2023-05-17 15:52:00

by Jorge Lopez

[permalink] [raw]
Subject: [PATCH v14 00/13] hp-bioscfg driver

HP BIOS Configuration driver purpose is to provide a driver supporting
the latest sysfs class firmware attributes framework allowing the user
to change BIOS settings and security solutions on HP Inc.’s commercial
notebooks.

Many features of HP Commercial notebooks can be managed using Windows
Management Instrumentation (WMI). WMI is an implementation of Web-Based
Enterprise Management (WBEM) that provides a standards-based interface
for changing and monitoring system settings. HP BIOSCFG driver provides
a native Linux solution and the exposed features facilitates the
migration to Linux environments.

The Linux security features to be provided in hp-bioscfg driver enables
managing the BIOS settings and security solutions via sysfs, a virtual
filesystem that can be used by user-mode applications. The new
documentation cover HP-specific firmware sysfs attributes such Secure
Platform Management and Sure Start. Each section provides security
feature description and identifies sysfs directories and files exposed
by the driver.

Many HP Commercial notebooks include a feature called Secure Platform
Management (SPM), which replaces older password-based BIOS settings
management with public key cryptography. PC secure product management
begins when a target system is provisioned with cryptographic keys
that are used to ensure the integrity of communications between system
management utilities and the BIOS.

HP Commercial notebooks have several BIOS settings that control its
behaviour and capabilities, many of which are related to security.
To prevent unauthorized changes to these settings, the system can
be configured to use a cryptographic signature-based authorization
string that the BIOS will use to verify authorization to modify the
setting.

Linux Security components are under development and not published yet.
The only linux component is the driver (hp bioscfg) at this time.
Other published security components are under Windows.

Signed-off-by: Jorge Lopez <[email protected]>

---
Based on the latest platform-drivers-x86.git/for-next

History

Version 14
Only patches marked [update] changed between version 14 and 13
Sorted commit patches alphabetically
Rename ordered-attributes to order-list-attributes

Patches
Documentation
biosattr-interface [update]
bioscfg
bioscfg-h
enum-attributes [update]
int-attributes
order-list-attributes
passwdattr-interface
spmobj-attributes
string-attributes
surestart-attributes
Makefile ../hp/Makefile ../hp/Kconfig
MAINTAINERS


Version 13
Only patches marked [update] changed between version 12 and 13
Sorted commit patches alphabetically
Rename ordered-attributes to order-list-attributes

Patches
Documentation [update]
biosattr-interface [update]
bioscfg [update]
bioscfg-h [update]
enum-attributes [update]
int-attributes [update]
order-list-attributes [update]
passwdattr-interface [update]
spmobj-attributes [update]
string-attributes [update]
surestart-attributes [update]
Makefile ../hp/Makefile ../hp/Kconfig
MAINTAINERS

Version 12
Only patches marked [update] changed between version 11 and 12

Patches
Documentation [update]
biosattr-interface [update]
bioscfg [update]
int-attributes [update]
ordered-attributes [update]
passwdobj-attributes [deleted]
string-attributes [update]
bioscfg-h [update]
enum-attributes [update]
passwdattr-interface [update]
spmobj-attributes [update]
surestart-attributes [update]
Makefile ../hp/Makefile ../hp/Kconfig [update]
MAINTAINERS


Version 11
Only patches marked [update] changed between version 10 and 11

Patches
Documentation
biosattr-interface [update]
bioscfg
int-attributes
ordered-attributes
passwdobj-attributes [update]
string-attributes
bioscfg-h
enum-attributes
passwdattr-interface
spmobj-attributes [update]
surestart-attributes [update]
Makefile ../hp/Makefile ../hp/Kconfig
MAINTAINERS

Version 10
Break down changes to single files per patch
Removed SPM/statusbin support
Patches
Documentation
biosattr-interface
bioscfg
int-attributes
ordered-attributes
passwdobj-attributes
string-attributes
bioscfg-h
enum-attributes
passwdattr-interface
spmobj-attributes
surestart-attributes
Makefile ../hp/Makefile ../hp/Kconfig
MAINTAINERS

Version 9
Includes only sysfs-class-firmware-attributes documentation

Version 8
Includes only sysfs-class-firmware-attributes documentation

Version 7
Includes only sysfs-class-firmware-attributes documentation

Version 6
Breaks down the changes into 4 patches
SureAdmin-attributes was removed

Version 5
Remove version 4 patch 1
Address review changes proposed in Version 4
Reorganize all patches number and file order




Jorge Lopez (13):
hp-bioscfg: Documentation
hp-bioscfg: bioscfg-h
hp-bioscfg: bioscfg
hp-bioscfg: biosattr-interface
hp-bioscfg: enum-attributes
hp-bioscfg: int-attributes
hp-bioscfg: order-list-attributes
hp-bioscfg: passwdobj-attributes
hp-bioscfg: spmobj-attributes
hp-bioscfg: string-attributes
hp-bioscfg: surestart-attributes
hp-bioscfg: Makefile
hp-bioscfg: MAINTAINERS

.../testing/sysfs-class-firmware-attributes | 102 +-
MAINTAINERS | 6 +
drivers/platform/x86/hp/Kconfig | 16 +
drivers/platform/x86/hp/Makefile | 1 +
drivers/platform/x86/hp/hp-bioscfg/Makefile | 11 +
.../x86/hp/hp-bioscfg/biosattr-interface.c | 317 ++++++
drivers/platform/x86/hp/hp-bioscfg/bioscfg.c | 988 ++++++++++++++++++
drivers/platform/x86/hp/hp-bioscfg/bioscfg.h | 486 +++++++++
.../x86/hp/hp-bioscfg/enum-attributes.c | 465 +++++++++
.../x86/hp/hp-bioscfg/int-attributes.c | 440 ++++++++
.../x86/hp/hp-bioscfg/order-list-attributes.c | 454 ++++++++
.../x86/hp/hp-bioscfg/passwdobj-attributes.c | 540 ++++++++++
.../x86/hp/hp-bioscfg/spmobj-attributes.c | 389 +++++++
.../x86/hp/hp-bioscfg/string-attributes.c | 404 +++++++
.../x86/hp/hp-bioscfg/surestart-attributes.c | 132 +++
15 files changed, 4749 insertions(+), 2 deletions(-)
create mode 100644 drivers/platform/x86/hp/hp-bioscfg/Makefile
create mode 100644 drivers/platform/x86/hp/hp-bioscfg/biosattr-interface.c
create mode 100644 drivers/platform/x86/hp/hp-bioscfg/bioscfg.c
create mode 100644 drivers/platform/x86/hp/hp-bioscfg/bioscfg.h
create mode 100644 drivers/platform/x86/hp/hp-bioscfg/enum-attributes.c
create mode 100644 drivers/platform/x86/hp/hp-bioscfg/int-attributes.c
create mode 100644 drivers/platform/x86/hp/hp-bioscfg/order-list-attributes.c
create mode 100644 drivers/platform/x86/hp/hp-bioscfg/passwdobj-attributes.c
create mode 100644 drivers/platform/x86/hp/hp-bioscfg/spmobj-attributes.c
create mode 100644 drivers/platform/x86/hp/hp-bioscfg/string-attributes.c
create mode 100644 drivers/platform/x86/hp/hp-bioscfg/surestart-attributes.c

--
2.34.1



2023-05-17 15:52:05

by Jorge Lopez

[permalink] [raw]
Subject: [PATCH v14 01/13] hp-bioscfg: Documentation

HP BIOS Configuration driver purpose is to provide a driver supporting
the latest sysfs class firmware attributes framework allowing the user
to change BIOS settings and security solutions on HP Inc.’s commercial
notebooks.

Many features of HP Commercial notebooks can be managed using Windows
Management Instrumentation (WMI). WMI is an implementation of Web-Based
Enterprise Management (WBEM) that provides a standards-based interface
for changing and monitoring system settings. HP BIOSCFG driver provides
a native Linux solution and the exposed features facilitates the
migration to Linux environments.

The Linux security features to be provided in hp-bioscfg driver enables
managing the BIOS settings and security solutions via sysfs, a virtual
filesystem that can be used by user-mode applications. The new
documentation cover HP-specific firmware sysfs attributes such Secure
Platform Management and Sure Start. Each section provides security
feature description and identifies sysfs directories and files exposed
by the driver.

Many HP Commercial notebooks include a feature called Secure Platform
Management (SPM), which replaces older password-based BIOS settings
management with public key cryptography. PC secure product management
begins when a target system is provisioned with cryptographic keys
that are used to ensure the integrity of communications between system
management utilities and the BIOS.

HP Commercial notebooks have several BIOS settings that control its
behaviour and capabilities, many of which are related to security.
To prevent unauthorized changes to these settings, the system can
be configured to use a cryptographic signature-based authorization
string that the BIOS will use to verify authorization to modify the
setting.

Linux Security components are under development and not published yet.
The only linux component is the driver (hp bioscfg) at this time.
Other published security components are under Windows.

Signed-off-by: Jorge Lopez <[email protected]>

---
Based on the latest platform-drivers-x86.git/for-next
---
.../testing/sysfs-class-firmware-attributes | 102 +++++++++++++++++-
1 file changed, 100 insertions(+), 2 deletions(-)

diff --git a/Documentation/ABI/testing/sysfs-class-firmware-attributes b/Documentation/ABI/testing/sysfs-class-firmware-attributes
index 4cdba3477176..f8d6c089228b 100644
--- a/Documentation/ABI/testing/sysfs-class-firmware-attributes
+++ b/Documentation/ABI/testing/sysfs-class-firmware-attributes
@@ -22,6 +22,11 @@ Description:
- integer: a range of numerical values
- string

+ HP specific types
+ -----------------
+ - ordered-list - a set of ordered list valid values
+
+
All attribute types support the following values:

current_value:
@@ -126,6 +131,22 @@ Description:
value will not be effective through sysfs until this rule is
met.

+ HP specific class extensions
+ ------------------------------
+
+ On HP systems the following additional attributes are available:
+
+ "ordered-list"-type specific properties:
+
+ elements:
+ A file that can be read to obtain the possible
+ list of values of the <attr>. Values are separated using
+ semi-colon (``;``). The order individual elements are listed
+ according to their priority. An element listed first has the
+ highest priority. Writing the list in a different order to
+ current_value alters the priority order for the particular
+ attribute.
+
What: /sys/class/firmware-attributes/*/authentication/
Date: February 2021
KernelVersion: 5.11
@@ -206,7 +227,7 @@ Description:
Drivers may emit a CHANGE uevent when a password is set or unset
userspace may check it again.

- On Dell and Lenovo systems, if Admin password is set, then all BIOS attributes
+ On Dell, Lenovo and HP systems, if Admin password is set, then all BIOS attributes
require password validation.
On Lenovo systems if you change the Admin password the new password is not active until
the next boot.
@@ -296,6 +317,15 @@ Description:
echo "signature" > authentication/Admin/signature
echo "password" > authentication/Admin/certificate_to_password

+ HP specific class extensions
+ --------------------------------
+
+ On HP systems the following additional settings are available:
+
+ role: enhanced-bios-auth:
+ This role is specific to Secure Platform Management (SPM) attribute.
+ It requires configuring an endorsement (kek) and signing certificate (sk).
+

What: /sys/class/firmware-attributes/*/attributes/pending_reboot
Date: February 2021
@@ -311,7 +341,7 @@ Description:
== =========================================
0 All BIOS attributes setting are current
1 A reboot is necessary to get pending BIOS
- attribute changes applied
+ attribute changes applied
== =========================================

Note, userspace applications need to follow below steps for efficient
@@ -364,3 +394,71 @@ Description:
use it to enable extra debug attributes or BIOS features for testing purposes.

Note that any changes to this attribute requires a reboot for changes to take effect.
+
+
+ HP specific class extensions - Secure Platform Manager (SPM)
+ --------------------------------
+
+What: /sys/class/firmware-attributes/*/authentication/SPM/kek
+Date: March 29
+KernelVersion: 5.18
+Contact: "Jorge Lopez" <[email protected]>
+Description:
+ 'kek' Key-Encryption-Key is a write-only file that can be used to configure the
+ RSA public key that will be used by the BIOS to verify
+ signatures when setting the signing key. When written,
+ the bytes should correspond to the KEK certificate
+ (x509 .DER format containing an OU). The size of the
+ certificate must be less than or equal to 4095 bytes.
+
+What: /sys/class/firmware-attributes/*/authentication/SPM/sk
+Date: March 29
+KernelVersion: 5.18
+Contact: "Jorge Lopez" <[email protected]>
+Description:
+ 'sk' Signature Key is a write-only file that can be used to configure the RSA
+ public key that will be used by the BIOS to verify signatures
+ when configuring BIOS settings and security features. When
+ written, the bytes should correspond to the modulus of the
+ public key. The exponent is assumed to be 0x10001.
+
+What: /sys/class/firmware-attributes/*/authentication/SPM/status
+Date: March 29
+KernelVersion: 5.18
+Contact: "Jorge Lopez" <[email protected]>
+Description:
+ 'status' is a read-only file that returns ASCII text in JSON format reporting
+ the status information.
+
+ "State": "not provisioned | provisioned | provisioning in progress ",
+ "Version": " Major. Minor ",
+ "Nonce": <16-bit unsigned number display in base 10>,
+ "FeaturesInUse": <16-bit unsigned number display in base 10>,
+ "EndorsementKeyMod": "<256 bytes in base64>",
+ "SigningKeyMod": "<256 bytes in base64>"
+
+What: /sys/class/firmware-attributes/*/attributes/Sure_Start/audit_log_entries
+Date: March 29
+KernelVersion: 5.18
+Contact: "Jorge Lopez" <[email protected]>
+Description:
+ 'audit_log_entries' is a read-only file that returns the events in the log.
+
+ Audit log entry format
+
+ Byte 0-15: Requested Audit Log entry (Each Audit log is 16 bytes)
+ Byte 16-127: Unused
+
+What: /sys/class/firmware-attributes/*/attributes/Sure_Start/audit_log_entry_count
+Date: March 29
+KernelVersion: 5.18
+Contact: "Jorge Lopez" <[email protected]>
+Description:
+ 'audit_log_entry_count' is a read-only file that returns the number of existing
+ audit log events available to be read. Values are separated using comma (``,``)
+
+ [No of entries],[log entry size],[Max number of entries supported]
+
+ log entry size identifies audit log size for the current BIOS version.
+ The current size is 16 bytes but it can be up to 128 bytes long in future BIOS
+ versions.
--
2.34.1


2023-05-17 15:52:22

by Jorge Lopez

[permalink] [raw]
Subject: [PATCH v14 07/13] hp-bioscfg: order-list-attributes

HP BIOS Configuration driver purpose is to provide a driver supporting
the latest sysfs class firmware attributes framework allowing the user
to change BIOS settings and security solutions on HP Inc.’s commercial
notebooks.

Many features of HP Commercial notebooks can be managed using Windows
Management Instrumentation (WMI). WMI is an implementation of Web-Based
Enterprise Management (WBEM) that provides a standards-based interface
for changing and monitoring system settings. HP BIOSCFG driver provides
a native Linux solution and the exposed features facilitates the
migration to Linux environments.

The Linux security features to be provided in hp-bioscfg driver enables
managing the BIOS settings and security solutions via sysfs, a virtual
filesystem that can be used by user-mode applications. The new
documentation cover HP-specific firmware sysfs attributes such Secure
Platform Management and Sure Start. Each section provides security
feature description and identifies sysfs directories and files exposed
by the driver.

Many HP Commercial notebooks include a feature called Secure Platform
Management (SPM), which replaces older password-based BIOS settings
management with public key cryptography. PC secure product management
begins when a target system is provisioned with cryptographic keys
that are used to ensure the integrity of communications between system
management utilities and the BIOS.

HP Commercial notebooks have several BIOS settings that control its
behaviour and capabilities, many of which are related to security.
To prevent unauthorized changes to these settings, the system can
be configured to use a cryptographic signature-based authorization
string that the BIOS will use to verify authorization to modify the
setting.

Linux Security components are under development and not published yet.
The only linux component is the driver (hp bioscfg) at this time.
Other published security components are under Windows.

Signed-off-by: Jorge Lopez <[email protected]>

---
Based on the latest platform-drivers-x86.git/for-next
---
.../x86/hp/hp-bioscfg/order-list-attributes.c | 454 ++++++++++++++++++
1 file changed, 454 insertions(+)
create mode 100644 drivers/platform/x86/hp/hp-bioscfg/order-list-attributes.c

diff --git a/drivers/platform/x86/hp/hp-bioscfg/order-list-attributes.c b/drivers/platform/x86/hp/hp-bioscfg/order-list-attributes.c
new file mode 100644
index 000000000000..73ed75e0e384
--- /dev/null
+++ b/drivers/platform/x86/hp/hp-bioscfg/order-list-attributes.c
@@ -0,0 +1,454 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Functions corresponding to ordered list type attributes under
+ * BIOS ORDERED LIST GUID for use with hp-bioscfg driver.
+ *
+ * Copyright (c) 2022 HP Development Company, L.P.
+ */
+
+#include "bioscfg.h"
+
+GET_INSTANCE_ID(ordered_list);
+
+static ssize_t current_value_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
+{
+ int instance_id = get_ordered_list_instance_id(kobj);
+
+ if (instance_id < 0)
+ return -EIO;
+
+ return sysfs_emit(buf, "%s\n",
+ bioscfg_drv.ordered_list_data[instance_id].current_value);
+}
+
+static int replace_char_str(u8 *buffer, char *repl_char, char *repl_with)
+{
+ char *src = buffer;
+ int buflen = strlen(buffer);
+ int item;
+
+ if (buflen < 1)
+ return -EINVAL;
+
+ for (item = 0; item < buflen; item++)
+ if (src[item] == *repl_char)
+ src[item] = *repl_with;
+
+ return 0;
+}
+
+/**
+ * validate_ordered_list_input() -
+ * Validate input of current_value against possible values
+ *
+ * @instance: The instance on which input is validated
+ * @buf: Input value
+ */
+static int validate_ordered_list_input(int instance, char *buf)
+{
+ /* validation is done by BIOS. This validation function will
+ * convert semicolon to commas. BIOS uses commas as
+ * separators when reporting ordered-list values.
+ */
+ return replace_char_str(buf, SEMICOLON_SEP, COMMA_SEP);
+}
+
+static void update_ordered_list_value(int instance, char *attr_value)
+{
+ struct ordered_list_data *ordered_list_data = &bioscfg_drv.ordered_list_data[instance];
+
+ strscpy(ordered_list_data->current_value,
+ attr_value,
+ sizeof(ordered_list_data->current_value));
+}
+
+ATTRIBUTE_S_COMMON_PROPERTY_SHOW(display_name, ordered_list);
+static struct kobj_attribute ordered_list_display_name =
+ __ATTR_RO(display_name);
+
+ATTRIBUTE_PROPERTY_STORE(current_value, ordered_list);
+static struct kobj_attribute ordered_list_current_val =
+ __ATTR_RW_MODE(current_value, 0644);
+
+ATTRIBUTE_VALUES_PROPERTY_SHOW(elements, ordered_list, SEMICOLON_SEP);
+static struct kobj_attribute ordered_list_elements_val =
+ __ATTR_RO(elements);
+
+static ssize_t type_show(struct kobject *kobj, struct kobj_attribute *attr,
+ char *buf)
+{
+ return sysfs_emit(buf, "ordered-list\n");
+}
+
+static struct kobj_attribute ordered_list_type =
+ __ATTR_RO(type);
+
+static struct kobj_attribute common_display_langcode =
+ __ATTR_RO(display_name_language_code);
+
+static struct attribute *ordered_list_attrs[] = {
+ &common_display_langcode.attr,
+ &ordered_list_display_name.attr,
+ &ordered_list_current_val.attr,
+ &ordered_list_elements_val.attr,
+ &ordered_list_type.attr,
+ NULL
+};
+
+static const struct attribute_group ordered_list_attr_group = {
+ .attrs = ordered_list_attrs,
+};
+
+int hp_alloc_ordered_list_data(void)
+{
+ bioscfg_drv.ordered_list_instances_count =
+ hp_get_instance_count(HP_WMI_BIOS_ORDERED_LIST_GUID);
+ bioscfg_drv.ordered_list_data = kcalloc(bioscfg_drv.ordered_list_instances_count,
+ sizeof(*bioscfg_drv.ordered_list_data),
+ GFP_KERNEL);
+ if (!bioscfg_drv.ordered_list_data) {
+ bioscfg_drv.ordered_list_instances_count = 0;
+ return -ENOMEM;
+ }
+ return 0;
+}
+
+/* Expected Values types associated with each element */
+static const acpi_object_type expected_order_types[] = {
+ [NAME] = ACPI_TYPE_STRING,
+ [VALUE] = ACPI_TYPE_STRING,
+ [PATH] = ACPI_TYPE_STRING,
+ [IS_READONLY] = ACPI_TYPE_INTEGER,
+ [DISPLAY_IN_UI] = ACPI_TYPE_INTEGER,
+ [REQUIRES_PHYSICAL_PRESENCE] = ACPI_TYPE_INTEGER,
+ [SEQUENCE] = ACPI_TYPE_INTEGER,
+ [PREREQUISITES_SIZE] = ACPI_TYPE_INTEGER,
+ [PREREQUISITES] = ACPI_TYPE_STRING,
+ [SECURITY_LEVEL] = ACPI_TYPE_INTEGER,
+ [ORD_LIST_SIZE] = ACPI_TYPE_INTEGER,
+ [ORD_LIST_ELEMENTS] = ACPI_TYPE_STRING,
+};
+
+static int hp_populate_ordered_list_elements_from_package(union acpi_object *order_obj,
+ int order_obj_count,
+ int instance_id)
+{
+ char *str_value = NULL;
+ int value_len;
+ int ret;
+ u32 size;
+ u32 int_value;
+ int elem;
+ int reqs;
+ int eloc;
+ char *tmpstr = NULL;
+ char *part_tmp = NULL;
+ int tmp_len = 0;
+ char *part = NULL;
+ struct ordered_list_data *ordered_list_data = &bioscfg_drv.ordered_list_data[instance_id];
+
+ if (!order_obj)
+ return -EINVAL;
+
+ for (elem = 1, eloc = 1; elem < order_obj_count; elem++, eloc++) {
+ /* ONLY look at the first ORDERED_ELEM_CNT elements */
+ if (eloc == ORD_ELEM_CNT)
+ goto exit_list;
+
+ switch (order_obj[elem].type) {
+ case ACPI_TYPE_STRING:
+ if (elem != PREREQUISITES && elem != ORD_LIST_ELEMENTS) {
+ ret = hp_convert_hexstr_to_str(order_obj[elem].string.pointer,
+ order_obj[elem].string.length,
+ &str_value, &value_len);
+ if (ret)
+ continue;
+ }
+ break;
+ case ACPI_TYPE_INTEGER:
+ int_value = (u32)order_obj[elem].integer.value;
+ break;
+ default:
+ pr_warn("Unsupported object type [%d]\n", order_obj[elem].type);
+ continue;
+ }
+
+ /* Check that both expected and read object type match */
+ if (expected_order_types[eloc] != order_obj[elem].type) {
+ pr_err("Error expected type %d for elem %d, but got type %d instead\n",
+ expected_order_types[eloc], elem, order_obj[elem].type);
+ return -EIO;
+ }
+
+ /* Assign appropriate element value to corresponding field*/
+ switch (eloc) {
+ case VALUE:
+ strscpy(ordered_list_data->current_value,
+ str_value, sizeof(ordered_list_data->current_value));
+ replace_char_str(ordered_list_data->current_value, COMMA_SEP, SEMICOLON_SEP);
+ break;
+ case PATH:
+ strscpy(ordered_list_data->common.path, str_value,
+ sizeof(ordered_list_data->common.path));
+ break;
+ case IS_READONLY:
+ ordered_list_data->common.is_readonly = int_value;
+ break;
+ case DISPLAY_IN_UI:
+ ordered_list_data->common.display_in_ui = int_value;
+ break;
+ case REQUIRES_PHYSICAL_PRESENCE:
+ ordered_list_data->common.requires_physical_presence = int_value;
+ break;
+ case SEQUENCE:
+ ordered_list_data->common.sequence = int_value;
+ break;
+ case PREREQUISITES_SIZE:
+ ordered_list_data->common.prerequisites_size = int_value;
+ if (int_value > MAX_PREREQUISITES_SIZE)
+ pr_warn("Prerequisites size value exceeded the maximum number of elements supported or data may be malformed\n");
+
+ /*
+ * This HACK is needed to keep the expected
+ * element list pointing to the right obj[elem].type
+ * when the size is zero. PREREQUISITES
+ * object is omitted by BIOS when the size is
+ * zero.
+ */
+ if (int_value == 0)
+ eloc++;
+ break;
+ case PREREQUISITES:
+ size = min_t(u32, ordered_list_data->common.prerequisites_size,
+ MAX_PREREQUISITES_SIZE);
+ for (reqs = 0; reqs < size; reqs++) {
+ ret = hp_convert_hexstr_to_str(order_obj[elem + reqs].string.pointer,
+ order_obj[elem + reqs].string.length,
+ &str_value, &value_len);
+
+ if (ret)
+ continue;
+
+ strscpy(ordered_list_data->common.prerequisites[reqs],
+ str_value,
+ sizeof(ordered_list_data->common.prerequisites[reqs]));
+
+ kfree(str_value);
+ }
+ break;
+
+ case SECURITY_LEVEL:
+ ordered_list_data->common.security_level = int_value;
+ break;
+
+ case ORD_LIST_SIZE:
+ ordered_list_data->elements_size = int_value;
+ if (int_value > MAX_ELEMENTS_SIZE)
+ pr_warn("Ordered List size value exceeded the maximum number of elements supported or data may be malformed\n");
+ /*
+ * This HACK is needed to keep the expected
+ * element list pointing to the right obj[elem].type
+ * when the size is zero. ORD_LIST_ELEMENTS
+ * object is omitted by BIOS when the size is
+ * zero.
+ */
+ if (int_value == 0)
+ eloc++;
+ break;
+ case ORD_LIST_ELEMENTS:
+ size = ordered_list_data->elements_size;
+
+ /*
+ * Ordered list data is stored in hex and comma separated format
+ * Convert the data and split it to show each element
+ */
+ ret = hp_convert_hexstr_to_str(str_value, value_len, &tmpstr, &tmp_len);
+ if (ret)
+ goto exit_list;
+
+ part_tmp = tmpstr;
+ part = strsep(&part_tmp, COMMA_SEP);
+ if (!part)
+ strscpy(ordered_list_data->elements[0],
+ tmpstr,
+ sizeof(ordered_list_data->elements[0]));
+
+ for (elem = 1; elem < MAX_ELEMENTS_SIZE && part; elem++) {
+ strscpy(ordered_list_data->elements[elem],
+ part,
+ sizeof(ordered_list_data->elements[elem]));
+ part = strsep(&part_tmp, SEMICOLON_SEP);
+ }
+
+ break;
+ default:
+ pr_warn("Invalid element: %d found in Ordered_List attribute or data may be malformed\n", elem);
+ break;
+ }
+ kfree(tmpstr);
+ kfree(str_value);
+ }
+
+exit_list:
+ kfree(tmpstr);
+ kfree(str_value);
+ return 0;
+}
+
+/**
+ * hp_populate_ordered_list_package_data() -
+ * Populate all properties of an instance under ordered_list attribute
+ *
+ * @order_obj: ACPI object with ordered_list data
+ * @instance_id: The instance to enumerate
+ * @attr_name_kobj: The parent kernel object
+ */
+int hp_populate_ordered_list_package_data(union acpi_object *order_obj, int instance_id,
+ struct kobject *attr_name_kobj)
+{
+ struct ordered_list_data *ordered_list_data = &bioscfg_drv.ordered_list_data[instance_id];
+
+ ordered_list_data->attr_name_kobj = attr_name_kobj;
+
+ hp_populate_ordered_list_elements_from_package(order_obj,
+ order_obj->package.count,
+ instance_id);
+ hp_update_attribute_permissions(ordered_list_data->common.is_readonly,
+ &ordered_list_current_val);
+ hp_friendly_user_name_update(ordered_list_data->common.path,
+ attr_name_kobj->name,
+ ordered_list_data->common.display_name,
+ sizeof(ordered_list_data->common.display_name));
+ return sysfs_create_group(attr_name_kobj, &ordered_list_attr_group);
+}
+
+static int hp_populate_ordered_list_elements_from_buffer(u8 *buffer_ptr, u32 *buffer_size,
+ int instance_id)
+{
+ int reqs;
+ int values;
+ struct ordered_list_data *ordered_list_data = &bioscfg_drv.ordered_list_data[instance_id];
+
+ /*
+ * In earlier implementation, reported errors were ignored
+ * causing the data to remain uninitialized. It is for this
+ * reason functions may return an error and no validation
+ * takes place.
+ */
+
+ // VALUE:
+ hp_get_string_from_buffer(&buffer_ptr, buffer_size, ordered_list_data->current_value,
+ sizeof(ordered_list_data->current_value));
+ replace_char_str(ordered_list_data->current_value, COMMA_SEP, SEMICOLON_SEP);
+
+ // PATH:
+ hp_get_string_from_buffer(&buffer_ptr, buffer_size, ordered_list_data->common.path,
+ sizeof(ordered_list_data->common.path));
+
+ // IS_READONLY:
+ hp_get_integer_from_buffer(&buffer_ptr, buffer_size,
+ &ordered_list_data->common.is_readonly);
+
+ //DISPLAY_IN_UI:
+ hp_get_integer_from_buffer(&buffer_ptr, buffer_size,
+ &ordered_list_data->common.display_in_ui);
+
+ // REQUIRES_PHYSICAL_PRESENCE:
+ hp_get_integer_from_buffer(&buffer_ptr, buffer_size,
+ &ordered_list_data->common.requires_physical_presence);
+
+ // SEQUENCE:
+ hp_get_integer_from_buffer(&buffer_ptr, buffer_size,
+ &ordered_list_data->common.sequence);
+
+ // PREREQUISITES_SIZE:
+ hp_get_integer_from_buffer(&buffer_ptr, buffer_size,
+ &ordered_list_data->common.prerequisites_size);
+
+ if (ordered_list_data->common.prerequisites_size > MAX_PREREQUISITES_SIZE) {
+ /* Report a message and limit prerequisite size to maximum value */
+ pr_warn("String Prerequisites size value exceeded the maximum number of elements supported or data may be malformed\n");
+ ordered_list_data->common.prerequisites_size = MAX_PREREQUISITES_SIZE;
+ }
+
+ // PREREQUISITES:
+ for (reqs = 0; reqs < ordered_list_data->common.prerequisites_size; reqs++)
+ hp_get_string_from_buffer(&buffer_ptr, buffer_size,
+ ordered_list_data->common.prerequisites[reqs],
+ sizeof(ordered_list_data->common.prerequisites[reqs]));
+
+ // SECURITY_LEVEL:
+ hp_get_integer_from_buffer(&buffer_ptr, buffer_size,
+ &ordered_list_data->common.security_level);
+
+ // ORD_LIST_SIZE:
+ hp_get_integer_from_buffer(&buffer_ptr, buffer_size,
+ &ordered_list_data->elements_size);
+
+ if (ordered_list_data->elements_size > MAX_ELEMENTS_SIZE) {
+ /* Report a message and limit elements size to maximum value */
+ pr_warn("Ordered List size value exceeded the maximum number of elements supported or data may be malformed\n");
+ ordered_list_data->elements_size = MAX_ELEMENTS_SIZE;
+ }
+
+ // ORD_LIST_ELEMENTS:
+ for (values = 0; values < ordered_list_data->elements_size; values++)
+ hp_get_string_from_buffer(&buffer_ptr, buffer_size,
+ ordered_list_data->elements[values],
+ sizeof(ordered_list_data->elements[values]));
+
+ return 0;
+}
+
+/**
+ * hp_populate_ordered_list_buffer_data() - Populate all properties of an
+ * instance under ordered list attribute
+ *
+ * @buffer_ptr: Buffer pointer
+ * @buffer_size: Buffer size
+ * @instance_id: The instance to enumerate
+ * @attr_name_kobj: The parent kernel object
+ */
+int hp_populate_ordered_list_buffer_data(u8 *buffer_ptr, u32 *buffer_size, int instance_id,
+ struct kobject *attr_name_kobj)
+{
+ struct ordered_list_data *ordered_list_data = &bioscfg_drv.ordered_list_data[instance_id];
+
+ ordered_list_data->attr_name_kobj = attr_name_kobj;
+
+ /* Populate ordered list elements */
+ hp_populate_ordered_list_elements_from_buffer(buffer_ptr, buffer_size,
+ instance_id);
+ hp_update_attribute_permissions(ordered_list_data->common.is_readonly,
+ &ordered_list_current_val);
+ hp_friendly_user_name_update(ordered_list_data->common.path,
+ attr_name_kobj->name,
+ ordered_list_data->common.display_name,
+ sizeof(ordered_list_data->common.display_name));
+
+ return sysfs_create_group(attr_name_kobj, &ordered_list_attr_group);
+}
+
+/**
+ * hp_exit_ordered_list_attributes() - Clear all attribute data
+ *
+ * Clears all data allocated for this group of attributes
+ */
+void hp_exit_ordered_list_attributes(void)
+{
+ int instance_id;
+
+ for (instance_id = 0; instance_id < bioscfg_drv.ordered_list_instances_count;
+ instance_id++) {
+ struct kobject *attr_name_kobj =
+ bioscfg_drv.ordered_list_data[instance_id].attr_name_kobj;
+
+ if (attr_name_kobj)
+ sysfs_remove_group(attr_name_kobj,
+ &ordered_list_attr_group);
+ }
+ bioscfg_drv.ordered_list_instances_count = 0;
+
+ kfree(bioscfg_drv.ordered_list_data);
+ bioscfg_drv.ordered_list_data = NULL;
+}
--
2.34.1


2023-05-17 15:52:24

by Jorge Lopez

[permalink] [raw]
Subject: [PATCH v14 08/13] hp-bioscfg: passwdobj-attributes

HP BIOS Configuration driver purpose is to provide a driver supporting
the latest sysfs class firmware attributes framework allowing the user
to change BIOS settings and security solutions on HP Inc.’s commercial
notebooks.

Many features of HP Commercial notebooks can be managed using Windows
Management Instrumentation (WMI). WMI is an implementation of Web-Based
Enterprise Management (WBEM) that provides a standards-based interface
for changing and monitoring system settings. HP BIOSCFG driver provides
a native Linux solution and the exposed features facilitates the
migration to Linux environments.

The Linux security features to be provided in hp-bioscfg driver enables
managing the BIOS settings and security solutions via sysfs, a virtual
filesystem that can be used by user-mode applications. The new
documentation cover HP-specific firmware sysfs attributes such Secure
Platform Management and Sure Start. Each section provides security
feature description and identifies sysfs directories and files exposed
by the driver.

Many HP Commercial notebooks include a feature called Secure Platform
Management (SPM), which replaces older password-based BIOS settings
management with public key cryptography. PC secure product management
begins when a target system is provisioned with cryptographic keys
that are used to ensure the integrity of communications between system
management utilities and the BIOS.

HP Commercial notebooks have several BIOS settings that control its
behaviour and capabilities, many of which are related to security.
To prevent unauthorized changes to these settings, the system can
be configured to use a cryptographic signature-based authorization
string that the BIOS will use to verify authorization to modify the
setting.

Linux Security components are under development and not published yet.
The only linux component is the driver (hp bioscfg) at this time.
Other published security components are under Windows.

Signed-off-by: Jorge Lopez <[email protected]>

---
Based on the latest platform-drivers-x86.git/for-next
---
.../x86/hp/hp-bioscfg/passwdobj-attributes.c | 540 ++++++++++++++++++
1 file changed, 540 insertions(+)
create mode 100644 drivers/platform/x86/hp/hp-bioscfg/passwdobj-attributes.c

diff --git a/drivers/platform/x86/hp/hp-bioscfg/passwdobj-attributes.c b/drivers/platform/x86/hp/hp-bioscfg/passwdobj-attributes.c
new file mode 100644
index 000000000000..483426696144
--- /dev/null
+++ b/drivers/platform/x86/hp/hp-bioscfg/passwdobj-attributes.c
@@ -0,0 +1,540 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Functions corresponding to password object type attributes under
+ * BIOS PASSWORD for use with hp-bioscfg driver.
+ *
+ * Copyright (c) 2022 HP Development Company, L.P.
+ */
+
+#include "bioscfg.h"
+#include <asm-generic/posix_types.h>
+
+GET_INSTANCE_ID(password);
+/*
+ * Clear all passwords copied to memory for a particular
+ * authentication instance
+ */
+static int clear_passwords(const int instance)
+{
+ struct password_data *password_data = &bioscfg_drv.password_data[instance];
+
+ if (!password_data->is_enabled)
+ return 0;
+
+ memset(password_data->current_password,
+ 0, sizeof(password_data->current_password));
+ memset(password_data->new_password,
+ 0, sizeof(password_data->new_password));
+
+ return 0;
+}
+
+/*
+ * Clear all credentials copied to memory for both Power-ON and Setup
+ * BIOS instances
+ */
+int hp_clear_all_credentials(void)
+{
+ int count = bioscfg_drv.password_instances_count;
+ int instance;
+
+ /* clear all passwords */
+ for (instance = 0; instance < count; instance++)
+ clear_passwords(instance);
+
+ /* clear auth_token */
+ kfree(bioscfg_drv.spm_data.auth_token);
+ bioscfg_drv.spm_data.auth_token = NULL;
+
+ return 0;
+}
+
+int hp_get_password_instance_for_type(const char *name)
+{
+ int count = bioscfg_drv.password_instances_count;
+ int instance;
+
+ for (instance = 0; instance < count; instance++)
+ if (!strcmp(bioscfg_drv.password_data[instance].common.display_name, name))
+ return instance;
+
+ return -EINVAL;
+}
+
+static int validate_password_input(int instance_id, const char *buf)
+{
+ int length;
+ struct password_data *password_data = &bioscfg_drv.password_data[instance_id];
+
+ length = strlen(buf);
+ if (buf[length - 1] == '\n')
+ length--;
+
+ if (length > MAX_PASSWD_SIZE)
+ return INVALID_BIOS_AUTH;
+
+ if (password_data->min_password_length > length ||
+ password_data->max_password_length < length)
+ return INVALID_BIOS_AUTH;
+ return SUCCESS;
+}
+
+ATTRIBUTE_N_PROPERTY_SHOW(is_enabled, password);
+static struct kobj_attribute password_is_password_set = __ATTR_RO(is_enabled);
+
+static int store_password_instance(struct kobject *kobj, const char *buf,
+ size_t count, bool is_current)
+{
+ char *buf_cp;
+ int id, ret = 0;
+
+ buf_cp = kstrdup(buf, GFP_KERNEL);
+ if (!buf_cp)
+ return -ENOMEM;
+
+ ret = hp_enforce_single_line_input(buf_cp, count);
+ if (!ret) {
+ id = get_password_instance_id(kobj);
+
+ if (id >= 0)
+ ret = validate_password_input(id, buf_cp);
+ }
+
+ if (!ret) {
+ if (is_current)
+ strscpy(bioscfg_drv.password_data[id].current_password,
+ buf_cp,
+ sizeof(bioscfg_drv.password_data[id].current_password));
+ else
+ strscpy(bioscfg_drv.password_data[id].new_password,
+ buf_cp,
+ sizeof(bioscfg_drv.password_data[id].new_password));
+ }
+
+ kfree(buf_cp);
+ return ret < 0 ? ret : count;
+}
+
+static ssize_t current_password_store(struct kobject *kobj,
+ struct kobj_attribute *attr,
+ const char *buf, size_t count)
+{
+ return store_password_instance(kobj, buf, count, true);
+}
+
+static struct kobj_attribute password_current_password = __ATTR_WO(current_password);
+
+static ssize_t new_password_store(struct kobject *kobj,
+ struct kobj_attribute *attr,
+ const char *buf, size_t count)
+{
+ return store_password_instance(kobj, buf, count, true);
+}
+
+static struct kobj_attribute password_new_password = __ATTR_WO(new_password);
+
+ATTRIBUTE_N_PROPERTY_SHOW(min_password_length, password);
+static struct kobj_attribute password_min_password_length = __ATTR_RO(min_password_length);
+
+ATTRIBUTE_N_PROPERTY_SHOW(max_password_length, password);
+static struct kobj_attribute password_max_password_length = __ATTR_RO(max_password_length);
+
+static ssize_t role_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
+{
+ if (!strcmp(kobj->name, SETUP_PASSWD))
+ return sysfs_emit(buf, "%s\n", BIOS_ADMIN);
+
+ if (!strcmp(kobj->name, POWER_ON_PASSWD))
+ return sysfs_emit(buf, "%s\n", POWER_ON);
+
+ return -EIO;
+}
+
+static struct kobj_attribute password_role = __ATTR_RO(role);
+
+static ssize_t mechanism_show(struct kobject *kobj, struct kobj_attribute *attr,
+ char *buf)
+{
+ int i = get_password_instance_id(kobj);
+
+ if (i < 0)
+ return i;
+
+ if (bioscfg_drv.password_data[i].mechanism != PASSWORD)
+ return -EINVAL;
+
+ return sysfs_emit(buf, "%s\n", PASSWD_MECHANISM_TYPES);
+}
+
+static struct kobj_attribute password_mechanism = __ATTR_RO(mechanism);
+
+ATTRIBUTE_VALUES_PROPERTY_SHOW(encodings, password, SEMICOLON_SEP);
+static struct kobj_attribute password_encodings_val = __ATTR_RO(encodings);
+
+static struct attribute *password_attrs[] = {
+ &password_is_password_set.attr,
+ &password_min_password_length.attr,
+ &password_max_password_length.attr,
+ &password_current_password.attr,
+ &password_new_password.attr,
+ &password_role.attr,
+ &password_mechanism.attr,
+ &password_encodings_val.attr,
+ NULL
+};
+
+static const struct attribute_group password_attr_group = {
+ .attrs = password_attrs
+};
+
+int hp_alloc_password_data(void)
+{
+ bioscfg_drv.password_instances_count = hp_get_instance_count(HP_WMI_BIOS_PASSWORD_GUID);
+ bioscfg_drv.password_data = kcalloc(bioscfg_drv.password_instances_count,
+ sizeof(*bioscfg_drv.password_data), GFP_KERNEL);
+ if (!bioscfg_drv.password_data) {
+ bioscfg_drv.password_instances_count = 0;
+ return -ENOMEM;
+ }
+
+ return 0;
+}
+
+/* Expected Values types associated with each element */
+static const acpi_object_type expected_password_types[] = {
+ [NAME] = ACPI_TYPE_STRING,
+ [VALUE] = ACPI_TYPE_STRING,
+ [PATH] = ACPI_TYPE_STRING,
+ [IS_READONLY] = ACPI_TYPE_INTEGER,
+ [DISPLAY_IN_UI] = ACPI_TYPE_INTEGER,
+ [REQUIRES_PHYSICAL_PRESENCE] = ACPI_TYPE_INTEGER,
+ [SEQUENCE] = ACPI_TYPE_INTEGER,
+ [PREREQUISITES_SIZE] = ACPI_TYPE_INTEGER,
+ [PREREQUISITES] = ACPI_TYPE_STRING,
+ [SECURITY_LEVEL] = ACPI_TYPE_INTEGER,
+ [PSWD_MIN_LENGTH] = ACPI_TYPE_INTEGER,
+ [PSWD_MAX_LENGTH] = ACPI_TYPE_INTEGER,
+ [PSWD_SIZE] = ACPI_TYPE_INTEGER,
+ [PSWD_ENCODINGS] = ACPI_TYPE_STRING,
+ [PSWD_IS_SET] = ACPI_TYPE_INTEGER,
+};
+
+static int hp_populate_password_elements_from_package(union acpi_object *password_obj,
+ int password_obj_count,
+ int instance_id)
+{
+ char *str_value = NULL;
+ int value_len;
+ int ret;
+ u32 size;
+ u32 int_value;
+ int elem;
+ int reqs;
+ int eloc;
+ int pos_values;
+ struct password_data *password_data = &bioscfg_drv.password_data[instance_id];
+
+ if (!password_obj)
+ return -EINVAL;
+
+ for (elem = 1, eloc = 1; elem < password_obj_count; elem++, eloc++) {
+ /* ONLY look at the first PASSWORD_ELEM_CNT elements */
+ if (eloc == PSWD_ELEM_CNT)
+ goto exit_package;
+
+ switch (password_obj[elem].type) {
+ case ACPI_TYPE_STRING:
+ if (PREREQUISITES != elem && PSWD_ENCODINGS != elem) {
+ ret = hp_convert_hexstr_to_str(password_obj[elem].string.pointer,
+ password_obj[elem].string.length,
+ &str_value, &value_len);
+ if (ret)
+ continue;
+ }
+ break;
+ case ACPI_TYPE_INTEGER:
+ int_value = (u32)password_obj[elem].integer.value;
+ break;
+ default:
+ pr_warn("Unsupported object type [%d]\n", password_obj[elem].type);
+ continue;
+ }
+
+ /* Check that both expected and read object type match */
+ if (expected_password_types[eloc] != password_obj[elem].type) {
+ pr_err("Error expected type %d for elem %d, but got type %d instead\n",
+ expected_password_types[eloc], elem, password_obj[elem].type);
+ return -EIO;
+ }
+
+ /* Assign appropriate element value to corresponding field*/
+ switch (eloc) {
+ case VALUE:
+ break;
+ case PATH:
+ strscpy(password_data->common.path, str_value,
+ sizeof(password_data->common.path));
+ break;
+ case IS_READONLY:
+ password_data->common.is_readonly = int_value;
+ break;
+ case DISPLAY_IN_UI:
+ password_data->common.display_in_ui = int_value;
+ break;
+ case REQUIRES_PHYSICAL_PRESENCE:
+ password_data->common.requires_physical_presence = int_value;
+ break;
+ case SEQUENCE:
+ password_data->common.sequence = int_value;
+ break;
+ case PREREQUISITES_SIZE:
+ password_data->common.prerequisites_size = int_value;
+ if (int_value > MAX_PREREQUISITES_SIZE)
+ pr_warn("Prerequisites size value exceeded the maximum number of elements supported or data may be malformed\n");
+
+ /* This HACK is needed to keep the expected
+ * element list pointing to the right obj[elem].type
+ * when the size is zero. PREREQUISITES
+ * object is omitted by BIOS when the size is
+ * zero.
+ */
+ if (int_value == 0)
+ eloc++;
+ break;
+ case PREREQUISITES:
+ size = min_t(u32, password_data->common.prerequisites_size,
+ MAX_PREREQUISITES_SIZE);
+
+ for (reqs = 0; reqs < size; reqs++) {
+ ret = hp_convert_hexstr_to_str(password_obj[elem + reqs].string.pointer,
+ password_obj[elem + reqs].string.length,
+ &str_value, &value_len);
+
+ if (ret)
+ break;
+
+ strscpy(password_data->common.prerequisites[reqs],
+ str_value,
+ sizeof(password_data->common.prerequisites[reqs]));
+
+ kfree(str_value);
+ }
+ break;
+ case SECURITY_LEVEL:
+ password_data->common.security_level = int_value;
+ break;
+ case PSWD_MIN_LENGTH:
+ password_data->min_password_length = int_value;
+ break;
+ case PSWD_MAX_LENGTH:
+ password_data->max_password_length = int_value;
+ break;
+ case PSWD_SIZE:
+ password_data->encodings_size = int_value;
+ if (int_value > MAX_ENCODINGS_SIZE)
+ pr_warn("Password Encoding size value exceeded the maximum number of elements supported or data may be malformed\n");
+
+ /* This HACK is needed to keep the expected
+ * element list pointing to the right obj[elem].type
+ * when the size is zero. PSWD_ENCODINGS
+ * object is omitted by BIOS when the size is
+ * zero.
+ */
+ if (int_value == 0)
+ eloc++;
+ break;
+ case PSWD_ENCODINGS:
+ size = min_t(u32, password_data->encodings_size, MAX_ENCODINGS_SIZE);
+ for (pos_values = 0; pos_values < size; pos_values++) {
+ ret = hp_convert_hexstr_to_str(password_obj[elem + pos_values].string.pointer,
+ password_obj[elem + pos_values].string.length,
+ &str_value, &value_len);
+ if (ret)
+ break;
+
+ strscpy(password_data->encodings[pos_values],
+ str_value,
+ sizeof(password_data->encodings[pos_values]));
+ kfree(str_value);
+ }
+ break;
+ case PSWD_IS_SET:
+ password_data->is_enabled = int_value;
+ break;
+ default:
+ pr_warn("Invalid element: %d found in Password attribute or data may be malformed\n", elem);
+ break;
+ }
+ }
+
+exit_package:
+ kfree(str_value);
+ return 0;
+}
+
+/**
+ * hp_populate_password_package_data()
+ * Populate all properties for an instance under password attribute
+ *
+ * @password_obj: ACPI object with password data
+ * @instance_id: The instance to enumerate
+ * @attr_name_kobj: The parent kernel object
+ */
+int hp_populate_password_package_data(union acpi_object *password_obj, int instance_id,
+ struct kobject *attr_name_kobj)
+{
+ struct password_data *password_data = &bioscfg_drv.password_data[instance_id];
+
+ password_data->attr_name_kobj = attr_name_kobj;
+
+ hp_populate_password_elements_from_package(password_obj,
+ password_obj->package.count,
+ instance_id);
+
+ hp_friendly_user_name_update(password_data->common.path,
+ attr_name_kobj->name,
+ password_data->common.display_name,
+ sizeof(password_data->common.display_name));
+
+ if (!strcmp(attr_name_kobj->name, SETUP_PASSWD))
+ return sysfs_create_group(attr_name_kobj, &password_attr_group);
+
+ return sysfs_create_group(attr_name_kobj, &password_attr_group);
+}
+
+static int hp_populate_password_elements_from_buffer(u8 *buffer_ptr, u32 *buffer_size,
+ int instance_id)
+{
+ int reqs;
+ int values;
+ int isreadonly;
+ struct password_data *password_data = &bioscfg_drv.password_data[instance_id];
+
+ // VALUE:
+ hp_get_string_from_buffer(&buffer_ptr, buffer_size, password_data->current_password,
+ sizeof(password_data->current_password));
+
+ // PATH:
+ hp_get_string_from_buffer(&buffer_ptr, buffer_size, password_data->common.path,
+ sizeof(password_data->common.path));
+
+ // IS_READONLY:
+ hp_get_integer_from_buffer(&buffer_ptr, buffer_size,
+ &password_data->common.is_readonly);
+
+ //DISPLAY_IN_UI:
+ hp_get_integer_from_buffer(&buffer_ptr, buffer_size,
+ &password_data->common.display_in_ui);
+
+ // REQUIRES_PHYSICAL_PRESENCE:
+ hp_get_integer_from_buffer(&buffer_ptr, buffer_size,
+ &password_data->common.requires_physical_presence);
+
+ // SEQUENCE:
+ hp_get_integer_from_buffer(&buffer_ptr, buffer_size,
+ &password_data->common.sequence);
+
+ // PREREQUISITES_SIZE:
+ hp_get_integer_from_buffer(&buffer_ptr, buffer_size,
+ &password_data->common.prerequisites_size);
+
+ if (password_data->common.prerequisites_size > MAX_PREREQUISITES_SIZE) {
+ /* Report a message and limit prerequisite size to maximum value */
+ pr_warn("Password Prerequisites size value exceeded the maximum number of elements supported or data may be malformed\n");
+ password_data->common.prerequisites_size = MAX_PREREQUISITES_SIZE;
+ }
+
+ // PREREQUISITES:
+ for (reqs = 0; reqs < password_data->common.prerequisites_size; reqs++)
+ hp_get_string_from_buffer(&buffer_ptr, buffer_size,
+ password_data->common.prerequisites[reqs],
+ sizeof(password_data->common.prerequisites[reqs]));
+
+ // SECURITY_LEVEL:
+ hp_get_integer_from_buffer(&buffer_ptr, buffer_size,
+ &password_data->common.security_level);
+
+ // PSWD_MIN_LENGTH:
+ hp_get_integer_from_buffer(&buffer_ptr, buffer_size,
+ &password_data->min_password_length);
+
+ // PSWD_MAX_LENGTH:
+ hp_get_integer_from_buffer(&buffer_ptr, buffer_size,
+ &password_data->max_password_length);
+
+ // PSWD_SIZE:
+ if (password_data->encodings_size > MAX_ENCODINGS_SIZE) {
+ /* Report a message and limit possible values size to maximum value */
+ pr_warn("Password Encoding size value exceeded the maximum number of elements supported or data may be malformed\n");
+ password_data->encodings_size = MAX_ENCODINGS_SIZE;
+ }
+
+ // PSWD_ENCODINGS:
+ for (values = 0; values < password_data->encodings_size; values++)
+ hp_get_string_from_buffer(&buffer_ptr, buffer_size,
+ password_data->encodings[values],
+ sizeof(password_data->encodings[values]));
+
+ // PSWD_IS_SET:
+ hp_get_integer_from_buffer(&buffer_ptr, buffer_size, &isreadonly);
+ password_data->is_enabled = isreadonly ? true : false;
+
+ return 0;
+}
+
+/**
+ * hp_populate_password_buffer_data()
+ * Populate all properties for an instance under password object attribute
+ *
+ * @buffer_ptr: Buffer pointer
+ * @buffer_size: Buffer size
+ * @instance_id: The instance to enumerate
+ * @attr_name_kobj: The parent kernel object
+ */
+int hp_populate_password_buffer_data(u8 *buffer_ptr, u32 *buffer_size, int instance_id,
+ struct kobject *attr_name_kobj)
+{
+ struct password_data *password_data = &bioscfg_drv.password_data[instance_id];
+
+ password_data->attr_name_kobj = attr_name_kobj;
+
+ /* Populate Password attributes */
+ hp_populate_password_elements_from_buffer(buffer_ptr, buffer_size,
+ instance_id);
+ hp_friendly_user_name_update(password_data->common.path,
+ attr_name_kobj->name,
+ password_data->common.display_name,
+ sizeof(password_data->common.display_name));
+ if (!strcmp(attr_name_kobj->name, SETUP_PASSWD))
+ return sysfs_create_group(attr_name_kobj, &password_attr_group);
+
+ return sysfs_create_group(attr_name_kobj, &password_attr_group);
+}
+
+/**
+ * hp_exit_password_attributes() - Clear all attribute data
+ *
+ * Clears all data allocated for this group of attributes
+ */
+void hp_exit_password_attributes(void)
+{
+ int instance_id;
+
+ for (instance_id = 0; instance_id < bioscfg_drv.password_instances_count;
+ instance_id++) {
+ struct kobject *attr_name_kobj =
+ bioscfg_drv.password_data[instance_id].attr_name_kobj;
+
+ if (attr_name_kobj) {
+ if (!strcmp(attr_name_kobj->name, SETUP_PASSWD))
+ sysfs_remove_group(attr_name_kobj,
+ &password_attr_group);
+ else
+ sysfs_remove_group(attr_name_kobj,
+ &password_attr_group);
+ }
+ }
+ bioscfg_drv.password_instances_count = 0;
+ kfree(bioscfg_drv.password_data);
+ bioscfg_drv.password_data = NULL;
+}
--
2.34.1


2023-05-17 15:53:54

by Jorge Lopez

[permalink] [raw]
Subject: [PATCH v14 03/13] hp-bioscfg: bioscfg

HP BIOS Configuration driver purpose is to provide a driver supporting
the latest sysfs class firmware attributes framework allowing the user
to change BIOS settings and security solutions on HP Inc.’s commercial
notebooks.

Many features of HP Commercial notebooks can be managed using Windows
Management Instrumentation (WMI). WMI is an implementation of Web-Based
Enterprise Management (WBEM) that provides a standards-based interface
for changing and monitoring system settings. HP BIOSCFG driver provides
a native Linux solution and the exposed features facilitates the
migration to Linux environments.

The Linux security features to be provided in hp-bioscfg driver enables
managing the BIOS settings and security solutions via sysfs, a virtual
filesystem that can be used by user-mode applications. The new
documentation cover HP-specific firmware sysfs attributes such Secure
Platform Management and Sure Start. Each section provides security
feature description and identifies sysfs directories and files exposed
by the driver.

Many HP Commercial notebooks include a feature called Secure Platform
Management (SPM), which replaces older password-based BIOS settings
management with public key cryptography. PC secure product management
begins when a target system is provisioned with cryptographic keys
that are used to ensure the integrity of communications between system
management utilities and the BIOS.

HP Commercial notebooks have several BIOS settings that control its
behaviour and capabilities, many of which are related to security.
To prevent unauthorized changes to these settings, the system can
be configured to use a cryptographic signature-based authorization
string that the BIOS will use to verify authorization to modify the
setting.

Linux Security components are under development and not published yet.
The only linux component is the driver (hp bioscfg) at this time.
Other published security components are under Windows.

Signed-off-by: Jorge Lopez <[email protected]>

---
Based on the latest platform-drivers-x86.git/for-next
---
drivers/platform/x86/hp/hp-bioscfg/bioscfg.c | 988 +++++++++++++++++++
1 file changed, 988 insertions(+)
create mode 100644 drivers/platform/x86/hp/hp-bioscfg/bioscfg.c

diff --git a/drivers/platform/x86/hp/hp-bioscfg/bioscfg.c b/drivers/platform/x86/hp/hp-bioscfg/bioscfg.c
new file mode 100644
index 000000000000..fe0be40c8dee
--- /dev/null
+++ b/drivers/platform/x86/hp/hp-bioscfg/bioscfg.c
@@ -0,0 +1,988 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Common methods for use with hp-bioscfg driver
+ *
+ * Copyright (c) 2022 HP Development Company, L.P.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/fs.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/wmi.h>
+#include "bioscfg.h"
+#include "../../firmware_attributes_class.h"
+#include <linux/nls.h>
+#include <linux/errno.h>
+
+MODULE_AUTHOR("Jorge Lopez <[email protected]>");
+MODULE_DESCRIPTION("HP BIOS Configuration Driver");
+MODULE_LICENSE("GPL");
+
+struct bioscfg_priv bioscfg_drv = {
+ .mutex = __MUTEX_INITIALIZER(bioscfg_drv.mutex),
+};
+
+static struct class *fw_attr_class;
+
+ssize_t display_name_language_code_show(struct kobject *kobj,
+ struct kobj_attribute *attr,
+ char *buf)
+{
+ return sysfs_emit(buf, "%s\n", bioscfg_drv.display_name_language_code);
+}
+
+int hp_get_integer_from_buffer(u8 **buffer, u32 *buffer_size, u32 *integer)
+{
+ int *ptr = PTR_ALIGN((int *)*buffer, 4);
+
+ /* Ensure there is enough space remaining to read the integer */
+ if (*buffer_size < sizeof(int))
+ return -EINVAL;
+
+ *integer = *(ptr++);
+ *buffer = (u8 *)ptr;
+ *buffer_size -= sizeof(int);
+
+ return 0;
+}
+
+int hp_get_string_from_buffer(u8 **buffer, u32 *buffer_size, char *dst, u32 dst_size)
+{
+ u16 *src = (u16 *)*buffer;
+ u16 src_size;
+
+ u16 size;
+ int i;
+ int conv_dst_size;
+
+ if (*buffer_size < sizeof(u16))
+ return -EINVAL;
+
+ src_size = *(src++);
+ /* size value in u16 chars */
+ size = src_size / sizeof(u16);
+
+ /* Ensure there is enough space remaining to read and convert
+ * the string
+ */
+ if (*buffer_size < src_size)
+ return -EINVAL;
+
+ for (i = 0; i < size; i++)
+ if (src[i] == '\\' ||
+ src[i] == '\r' ||
+ src[i] == '\n' ||
+ src[i] == '\t')
+ size++;
+
+ /*
+ * Conversion is limited to destination string max number of
+ * bytes.
+ */
+ conv_dst_size = size;
+ if (size > dst_size)
+ conv_dst_size = dst_size - 1;
+
+ /*
+ * convert from UTF-16 unicode to ASCII
+ */
+ utf16s_to_utf8s(src, src_size, UTF16_HOST_ENDIAN, dst, conv_dst_size);
+ dst[conv_dst_size] = 0;
+
+ for (i = 0; i < size && i < conv_dst_size; i++) {
+ if (*src == '\\' ||
+ *src == '\r' ||
+ *src == '\n' ||
+ *src == '\t')
+ dst[i++] = '\\';
+
+ if (*src == '\r')
+ dst[i] = 'r';
+ else if (*src == '\n')
+ dst[i] = 'n';
+ else if (*src == '\t')
+ dst[i] = 't';
+ else if (*src == '"')
+ dst[i] = '\'';
+ else
+ dst[i] = *src;
+ src++;
+ }
+
+ *buffer = (u8 *)src;
+ *buffer_size -= size * sizeof(u16);
+
+ return size;
+}
+
+int hp_enforce_single_line_input(char *buf, size_t count)
+{
+ char *p;
+
+ p = memchr(buf, '\n', count);
+
+ if (p == buf + count - 1)
+ *p = '\0'; /* strip trailing newline */
+ else if (p)
+ return -EINVAL; /* enforce single line input */
+
+ return 0;
+}
+
+/* Set pending reboot value and generate KOBJ_NAME event */
+void hp_set_reboot_and_signal_event(void)
+{
+ bioscfg_drv.pending_reboot = true;
+ kobject_uevent(&bioscfg_drv.class_dev->kobj, KOBJ_CHANGE);
+}
+
+/**
+ * hp_calculate_string_buffer() - determines size of string buffer for
+ * use with BIOS communication
+ *
+ * @str: the string to calculate based upon
+ */
+size_t hp_calculate_string_buffer(const char *str)
+{
+ size_t length = strlen(str);
+
+ /* BIOS expects 4 bytes when an empty string is found */
+ if (length == 0)
+ return 4;
+
+ /* u16 length field + one UTF16 char for each input char */
+ return sizeof(u16) + strlen(str) * sizeof(u16);
+}
+
+int hp_wmi_error_and_message(int error_code)
+{
+ char *error_msg = NULL;
+ int ret;
+
+ switch (error_code) {
+ case SUCCESS:
+ error_msg = "Success";
+ ret = 0;
+ break;
+ case CMD_FAILED:
+ error_msg = "Command failed";
+ ret = -EINVAL;
+ break;
+ case INVALID_SIGN:
+ error_msg = "Invalid signature";
+ ret = -EINVAL;
+ break;
+ case INVALID_CMD_VALUE:
+ error_msg = "Invalid command value/Feature not supported";
+ ret = -EOPNOTSUPP;
+ break;
+ case INVALID_CMD_TYPE:
+ error_msg = "Invalid command type";
+ ret = -EINVAL;
+ break;
+ case INVALID_DATA_SIZE:
+ error_msg = "Invalid data size";
+ ret = -EINVAL;
+ break;
+ case INVALID_CMD_PARAM:
+ error_msg = "Invalid command parameter";
+ ret = -EINVAL;
+ break;
+ case ENCRYP_CMD_REQUIRED:
+ error_msg = "Secure/encrypted command required";
+ ret = -EACCES;
+ break;
+ case NO_SECURE_SESSION:
+ error_msg = "No secure session established";
+ ret = -EACCES;
+ break;
+ case SECURE_SESSION_FOUND:
+ error_msg = "Secure session already established";
+ ret = -EACCES;
+ break;
+ case SECURE_SESSION_FAILED:
+ error_msg = "Secure session failed";
+ ret = -EIO;
+ break;
+ case AUTH_FAILED:
+ error_msg = "Other permission/Authentication failed";
+ ret = -EACCES;
+ break;
+ case INVALID_BIOS_AUTH:
+ error_msg = "Invalid BIOS administrator password";
+ ret = -EINVAL;
+ break;
+ case NONCE_DID_NOT_MATCH:
+ error_msg = "Nonce did not match";
+ ret = -EINVAL;
+ break;
+ case GENERIC_ERROR:
+ error_msg = "Generic/Other error";
+ ret = -EIO;
+ break;
+ case BIOS_ADMIN_POLICY_NOT_MET:
+ error_msg = "BIOS Admin password does not meet password policy requirements";
+ ret = -EINVAL;
+ break;
+ case BIOS_ADMIN_NOT_SET:
+ error_msg = "BIOS Setup password is not set";
+ ret = -EPERM;
+ break;
+ case P21_NO_PROVISIONED:
+ error_msg = "P21 is not provisioned";
+ ret = -EPERM;
+ break;
+ case P21_PROVISION_IN_PROGRESS:
+ error_msg = "P21 is already provisioned or provisioning is in progress and a signing key has already been sent";
+ ret = -EINPROGRESS;
+ break;
+ case P21_IN_USE:
+ error_msg = "P21 in use (cannot deprovision)";
+ ret = -EPERM;
+ break;
+ case HEP_NOT_ACTIVE:
+ error_msg = "HEP not activated";
+ ret = -EPERM;
+ break;
+ case HEP_ALREADY_SET:
+ error_msg = "HEP Transport already set";
+ ret = -EINVAL;
+ break;
+ case HEP_CHECK_STATE:
+ error_msg = "Check the current HEP state";
+ ret = -EINVAL;
+ break;
+ default:
+ error_msg = "Generic/Other error";
+ ret = -EIO;
+ break;
+ }
+
+ if (error_code)
+ pr_warn_ratelimited("Returned error 0x%x, \"%s\"\n", error_code, error_msg);
+
+ return ret;
+}
+
+static ssize_t pending_reboot_show(struct kobject *kobj,
+ struct kobj_attribute *attr,
+ char *buf)
+{
+ return sysfs_emit(buf, "%d\n", bioscfg_drv.pending_reboot);
+}
+
+static struct kobj_attribute pending_reboot = __ATTR_RO(pending_reboot);
+
+/*
+ * create_attributes_level_sysfs_files() - Creates pending_reboot attributes
+ */
+static int create_attributes_level_sysfs_files(void)
+{
+ return sysfs_create_file(&bioscfg_drv.main_dir_kset->kobj,
+ &pending_reboot.attr);
+}
+
+static void attr_name_release(struct kobject *kobj)
+{
+ kfree(kobj);
+}
+
+static const struct kobj_type attr_name_ktype = {
+ .release = attr_name_release,
+ .sysfs_ops = &kobj_sysfs_ops,
+};
+
+/**
+ * hp_get_wmiobj_pointer() - Get Content of WMI block for particular instance
+ *
+ * @instance_id: WMI instance ID
+ * @guid_string: WMI GUID (in str form)
+ *
+ * Fetches the content for WMI block (instance_id) under GUID (guid_string)
+ * Caller must kfree the return
+ */
+union acpi_object *hp_get_wmiobj_pointer(int instance_id, const char *guid_string)
+{
+ struct acpi_buffer out = { ACPI_ALLOCATE_BUFFER, NULL };
+ acpi_status status;
+
+ status = wmi_query_block(guid_string, instance_id, &out);
+ return ACPI_SUCCESS(status) ? (union acpi_object *)out.pointer : NULL;
+}
+
+/**
+ * hp_get_instance_count() - Compute total number of instances under guid_string
+ *
+ * @guid_string: WMI GUID (in string form)
+ */
+int hp_get_instance_count(const char *guid_string)
+{
+ union acpi_object *wmi_obj = NULL;
+ int i = 0;
+
+ do {
+ kfree(wmi_obj);
+ wmi_obj = hp_get_wmiobj_pointer(i, guid_string);
+ i++;
+ } while (wmi_obj);
+
+ return i - 1;
+}
+
+/**
+ * hp_alloc_attributes_data() - Allocate attributes data for a particular type
+ *
+ * @attr_type: Attribute type to allocate
+ */
+static int hp_alloc_attributes_data(int attr_type)
+{
+ switch (attr_type) {
+ case HPWMI_STRING_TYPE:
+ return hp_alloc_string_data();
+
+ case HPWMI_INTEGER_TYPE:
+ return hp_alloc_integer_data();
+
+ case HPWMI_ENUMERATION_TYPE:
+ return hp_alloc_enumeration_data();
+
+ case HPWMI_ORDERED_LIST_TYPE:
+ return hp_alloc_ordered_list_data();
+
+ case HPWMI_PASSWORD_TYPE:
+ return hp_alloc_password_data();
+
+ default:
+ return 0;
+ }
+}
+
+int hp_convert_hexstr_to_str(const char *input, u32 input_len, char **str, int *len)
+{
+ int ret = 0;
+ int new_len = 0;
+ char tmp[] = "0x00";
+ char *new_str = NULL;
+ long ch;
+ int i;
+
+ if (input_len <= 0 || !input || !str || !len)
+ return -EINVAL;
+
+ *len = 0;
+ *str = NULL;
+
+ new_str = kmalloc(input_len, GFP_KERNEL);
+ if (!new_str)
+ return -ENOMEM;
+
+ for (i = 0; i < input_len; i += 5) {
+ strncpy(tmp, input + i, strlen(tmp));
+ if (kstrtol(tmp, 16, &ch) == 0) {
+ // escape char
+ if (ch == '\\' ||
+ ch == '\r' ||
+ ch == '\n' || ch == '\t') {
+ if (ch == '\r')
+ ch = 'r';
+ else if (ch == '\n')
+ ch = 'n';
+ else if (ch == '\t')
+ ch = 't';
+ new_str[new_len++] = '\\';
+ }
+ new_str[new_len++] = ch;
+ if (ch == '\0')
+ break;
+ }
+ }
+
+ if (new_len) {
+ new_str[new_len] = '\0';
+ *str = krealloc(new_str, (new_len + 1) * sizeof(char),
+ GFP_KERNEL);
+ if (*str)
+ *len = new_len;
+ else
+ ret = -ENOMEM;
+ } else {
+ ret = -EFAULT;
+ }
+
+ if (ret)
+ kfree(new_str);
+ return ret;
+}
+
+/* map output size to the corresponding WMI method id */
+int hp_encode_outsize_for_pvsz(int outsize)
+{
+ if (outsize > 4096)
+ return -EINVAL;
+ if (outsize > 1024)
+ return 5;
+ if (outsize > 128)
+ return 4;
+ if (outsize > 4)
+ return 3;
+ if (outsize > 0)
+ return 2;
+ return 1;
+}
+
+/*
+ * Update friendly display name for several attributes associated to
+ * 'Schedule Power-On'
+ */
+void hp_friendly_user_name_update(char *path, const char *attr_name,
+ char *attr_display, int attr_size)
+{
+ if (strstr(path, SCHEDULE_POWER_ON))
+ snprintf(attr_display, attr_size, "%s - %s", SCHEDULE_POWER_ON, attr_name);
+ else
+ strscpy(attr_display, attr_name, attr_size);
+}
+
+/**
+ * hp_update_attribute_permissions() - Update attributes permissions when
+ * isReadOnly value is 1
+ *
+ * @is_readonly: bool value to indicate if it a readonly attribute.
+ * @current_val: kobj_attribute corresponding to attribute.
+ *
+ */
+void hp_update_attribute_permissions(bool is_readonly, struct kobj_attribute *current_val)
+{
+ current_val->attr.mode = is_readonly ? 0444 : 0644;
+}
+
+/**
+ * destroy_attribute_objs() - Free a kset of kobjects
+ * @kset: The kset to destroy
+ *
+ * Fress kobjects created for each attribute_name under attribute type kset
+ */
+static void destroy_attribute_objs(struct kset *kset)
+{
+ struct kobject *pos, *next;
+
+ list_for_each_entry_safe(pos, next, &kset->list, entry)
+ kobject_put(pos);
+}
+
+/**
+ * release_attributes_data() - Clean-up all sysfs directories and files created
+ */
+static void release_attributes_data(void)
+{
+ mutex_lock(&bioscfg_drv.mutex);
+
+ hp_exit_string_attributes();
+ hp_exit_integer_attributes();
+ hp_exit_enumeration_attributes();
+ hp_exit_ordered_list_attributes();
+ hp_exit_password_attributes();
+ hp_exit_sure_start_attributes();
+ hp_exit_secure_platform_attributes();
+
+ if (bioscfg_drv.authentication_dir_kset) {
+ destroy_attribute_objs(bioscfg_drv.authentication_dir_kset);
+ kset_unregister(bioscfg_drv.authentication_dir_kset);
+ bioscfg_drv.authentication_dir_kset = NULL;
+ }
+ if (bioscfg_drv.main_dir_kset) {
+ sysfs_remove_file(&bioscfg_drv.main_dir_kset->kobj, &pending_reboot.attr);
+ destroy_attribute_objs(bioscfg_drv.main_dir_kset);
+ kset_unregister(bioscfg_drv.main_dir_kset);
+ bioscfg_drv.main_dir_kset = NULL;
+ }
+ mutex_unlock(&bioscfg_drv.mutex);
+}
+
+/**
+ * hp_add_other_attributes() - Initialize HP custom attributes not
+ * reported by BIOS and required to support Secure Platform and Sure
+ * Start.
+ *
+ * @attr_type: Custom HP attribute not reported by BIOS
+ *
+ * Initialize all 2 types of attributes: Platform and Sure Start
+ * object. Populates each attribute types respective properties
+ * under sysfs files.
+ *
+ * Returns zero(0) if successful. Otherwise, a negative value.
+ */
+static int hp_add_other_attributes(int attr_type)
+{
+ struct kobject *attr_name_kobj;
+ union acpi_object *obj = NULL;
+ int retval;
+ char *attr_name;
+
+ mutex_lock(&bioscfg_drv.mutex);
+
+ attr_name_kobj = kzalloc(sizeof(*attr_name_kobj), GFP_KERNEL);
+ if (!attr_name_kobj) {
+ retval = -ENOMEM;
+ goto err_other_attr_init;
+ }
+
+ /* Check if attribute type is supported */
+ switch (attr_type) {
+ case HPWMI_SECURE_PLATFORM_TYPE:
+ attr_name_kobj->kset = bioscfg_drv.authentication_dir_kset;
+ attr_name = SPM_STR;
+ break;
+
+ case HPWMI_SURE_START_TYPE:
+ attr_name_kobj->kset = bioscfg_drv.main_dir_kset;
+ attr_name = SURE_START_STR;
+ break;
+
+ default:
+ pr_err("Error: Unknown attr_type: %d\n", attr_type);
+ retval = -EINVAL;
+ goto err_other_attr_init;
+ }
+
+ retval = kobject_init_and_add(attr_name_kobj, &attr_name_ktype,
+ NULL, "%s", attr_name);
+ if (retval) {
+ pr_err("Error encountered [%d]\n", retval);
+ kobject_put(attr_name_kobj);
+ goto err_other_attr_init;
+ }
+
+ /* Populate attribute data */
+ switch (attr_type) {
+ case HPWMI_SECURE_PLATFORM_TYPE:
+ retval = hp_populate_secure_platform_data(attr_name_kobj);
+ break;
+
+ case HPWMI_SURE_START_TYPE:
+ retval = hp_populate_sure_start_data(attr_name_kobj);
+ break;
+
+ default:
+ goto err_other_attr_init;
+ }
+
+ mutex_unlock(&bioscfg_drv.mutex);
+ return 0;
+
+err_other_attr_init:
+ mutex_unlock(&bioscfg_drv.mutex);
+ kfree(obj);
+ return retval;
+}
+
+static int hp_init_bios_package_attribute(enum hp_wmi_data_type attr_type,
+ union acpi_object *obj,
+ const char *guid, int min_elements,
+ int instance_id)
+{
+ struct kobject *attr_name_kobj;
+ union acpi_object *elements;
+ struct kset *temp_kset;
+
+ char *str_value = NULL;
+ int str_len;
+ int retval = 0;
+
+ /* Take action appropriate to each ACPI TYPE */
+ if (obj->package.count < min_elements) {
+ pr_err("ACPI-package does not have enough elements: %d < %d\n",
+ obj->package.count, min_elements);
+ goto pack_attr_exit;
+ }
+
+ elements = obj->package.elements;
+
+ /* sanity checking */
+ if (elements[NAME].type != ACPI_TYPE_STRING) {
+ pr_debug("incorrect element type\n");
+ goto pack_attr_exit;
+ }
+ if (strlen(elements[NAME].string.pointer) == 0) {
+ pr_debug("empty attribute found\n");
+ goto pack_attr_exit;
+ }
+
+ if (attr_type == HPWMI_PASSWORD_TYPE)
+ temp_kset = bioscfg_drv.authentication_dir_kset;
+ else
+ temp_kset = bioscfg_drv.main_dir_kset;
+
+ /* convert attribute name to string */
+ retval = hp_convert_hexstr_to_str(elements[NAME].string.pointer,
+ elements[NAME].string.length,
+ &str_value, &str_len);
+
+ if (retval) {
+ pr_debug("Failed to populate integer package data. Error [0%0x]\n",
+ retval);
+ kfree(str_value);
+ return retval;
+ }
+
+ /* All duplicate attributes found are ignored */
+ if (kset_find_obj(temp_kset, str_value)) {
+ pr_debug("Duplicate attribute name found - %s\n",
+ str_value);
+ goto pack_attr_exit;
+ }
+
+ /* build attribute */
+ attr_name_kobj = kzalloc(sizeof(*attr_name_kobj), GFP_KERNEL);
+ if (!attr_name_kobj) {
+ retval = -ENOMEM;
+ goto pack_attr_exit;
+ }
+
+ attr_name_kobj->kset = temp_kset;
+
+ retval = kobject_init_and_add(attr_name_kobj, &attr_name_ktype,
+ NULL, "%s", str_value);
+
+ if (retval) {
+ kobject_put(attr_name_kobj);
+ goto pack_attr_exit;
+ }
+
+ /* enumerate all of these attributes */
+ switch (attr_type) {
+ case HPWMI_STRING_TYPE:
+ retval = hp_populate_string_package_data(elements,
+ instance_id,
+ attr_name_kobj);
+ break;
+ case HPWMI_INTEGER_TYPE:
+ retval = hp_populate_integer_package_data(elements,
+ instance_id,
+ attr_name_kobj);
+ break;
+ case HPWMI_ENUMERATION_TYPE:
+ retval = hp_populate_enumeration_package_data(elements,
+ instance_id,
+ attr_name_kobj);
+ break;
+ case HPWMI_ORDERED_LIST_TYPE:
+ retval = hp_populate_ordered_list_package_data(elements,
+ instance_id,
+ attr_name_kobj);
+ break;
+ case HPWMI_PASSWORD_TYPE:
+ retval = hp_populate_password_package_data(elements,
+ instance_id,
+ attr_name_kobj);
+ break;
+ default:
+ pr_debug("Unknown attribute type found: 0x%x\n", attr_type);
+ break;
+ }
+
+pack_attr_exit:
+ kfree(str_value);
+ return retval;
+}
+
+static int hp_init_bios_buffer_attribute(enum hp_wmi_data_type attr_type,
+ union acpi_object *obj,
+ const char *guid, int min_elements,
+ int instance_id)
+{
+ struct kobject *attr_name_kobj;
+ struct kset *temp_kset;
+ char str[MAX_BUFF_SIZE];
+
+ char *temp_str = NULL;
+ char *str_value = NULL;
+ u8 *buffer_ptr = NULL;
+ int buffer_size;
+ int retval = 0;
+
+ buffer_size = obj->buffer.length;
+ buffer_ptr = obj->buffer.pointer;
+
+ retval = hp_get_string_from_buffer(&buffer_ptr,
+ &buffer_size, str, MAX_BUFF_SIZE);
+
+ if (retval < 0)
+ goto buff_attr_exit;
+
+ if (attr_type == HPWMI_PASSWORD_TYPE ||
+ attr_type == HPWMI_SECURE_PLATFORM_TYPE)
+ temp_kset = bioscfg_drv.authentication_dir_kset;
+ else
+ temp_kset = bioscfg_drv.main_dir_kset;
+
+ /* All duplicate attributes found are ignored */
+ if (kset_find_obj(temp_kset, str)) {
+ pr_debug("Duplicate attribute name found - %s\n", str);
+ goto buff_attr_exit;
+ }
+
+ /* build attribute */
+ attr_name_kobj = kzalloc(sizeof(*attr_name_kobj), GFP_KERNEL);
+ if (!attr_name_kobj) {
+ retval = -ENOMEM;
+ goto buff_attr_exit;
+ }
+
+ attr_name_kobj->kset = temp_kset;
+
+ temp_str = str;
+ if (attr_type == HPWMI_SECURE_PLATFORM_TYPE)
+ temp_str = "SPM";
+
+ retval = kobject_init_and_add(attr_name_kobj,
+ &attr_name_ktype, NULL, "%s",
+ temp_str);
+ if (retval) {
+ kobject_put(attr_name_kobj);
+ goto buff_attr_exit;
+ }
+
+ /* enumerate all of these attributes */
+ switch (attr_type) {
+ case HPWMI_STRING_TYPE:
+ retval = hp_populate_string_buffer_data(buffer_ptr,
+ &buffer_size,
+ instance_id,
+ attr_name_kobj);
+ break;
+ case HPWMI_INTEGER_TYPE:
+ retval = hp_populate_integer_buffer_data(buffer_ptr,
+ &buffer_size,
+ instance_id,
+ attr_name_kobj);
+ break;
+ case HPWMI_ENUMERATION_TYPE:
+ retval = hp_populate_enumeration_buffer_data(buffer_ptr,
+ &buffer_size,
+ instance_id,
+ attr_name_kobj);
+ break;
+ case HPWMI_ORDERED_LIST_TYPE:
+ retval = hp_populate_ordered_list_buffer_data(buffer_ptr,
+ &buffer_size,
+ instance_id,
+ attr_name_kobj);
+ break;
+ case HPWMI_PASSWORD_TYPE:
+ retval = hp_populate_password_buffer_data(buffer_ptr,
+ &buffer_size,
+ instance_id,
+ attr_name_kobj);
+ break;
+ default:
+ pr_debug("Unknown attribute type found: 0x%x\n", attr_type);
+ break;
+ }
+
+buff_attr_exit:
+ kfree(str_value);
+ return retval;
+}
+
+/**
+ * hp_init_bios_attributes() - Initialize all attributes for a type
+ * @attr_type: The attribute type to initialize
+ * @guid: The WMI GUID associated with this type to initialize
+ *
+ * Initialiaze all 5 types of attributes: enumeration, integer,
+ * string, password, ordered list object. Populates each attrbute types
+ * respective properties under sysfs files
+ */
+static int hp_init_bios_attributes(enum hp_wmi_data_type attr_type, const char *guid)
+{
+ union acpi_object *obj = NULL;
+ int min_elements;
+
+ /* instance_id needs to be reset for each type GUID
+ * also, instance IDs are unique within GUID but not across
+ */
+ int instance_id = 0;
+ int retval = 0;
+
+ retval = hp_alloc_attributes_data(attr_type);
+ if (retval)
+ return retval;
+
+ switch (attr_type) {
+ case HPWMI_STRING_TYPE:
+ min_elements = STR_ELEM_CNT;
+ break;
+ case HPWMI_INTEGER_TYPE:
+ min_elements = INT_ELEM_CNT;
+ break;
+ case HPWMI_ENUMERATION_TYPE:
+ min_elements = ENUM_ELEM_CNT;
+ break;
+ case HPWMI_ORDERED_LIST_TYPE:
+ min_elements = ORD_ELEM_CNT;
+ break;
+ case HPWMI_PASSWORD_TYPE:
+ min_elements = PSWD_ELEM_CNT;
+ break;
+ default:
+ pr_err("Error: Unknown attr_type: %d\n", attr_type);
+ return -EINVAL;
+ }
+
+ /* Report display name language code */
+ strscpy(bioscfg_drv.display_name_language_code,
+ LANG_CODE_STR,
+ sizeof(bioscfg_drv.display_name_language_code));
+
+ /* need to use specific instance_id and guid combination to get right data */
+ obj = hp_get_wmiobj_pointer(instance_id, guid);
+ if (!obj)
+ return -ENODEV;
+
+ mutex_lock(&bioscfg_drv.mutex);
+ while (obj) {
+ /* Take action appropriate to each ACPI TYPE */
+ if (obj->type == ACPI_TYPE_PACKAGE) {
+ retval = hp_init_bios_package_attribute(attr_type, obj,
+ guid, min_elements,
+ instance_id);
+ if (retval)
+ goto err_attr_init;
+ } else if (obj->type == ACPI_TYPE_BUFFER) {
+ retval = hp_init_bios_buffer_attribute(attr_type, obj,
+ guid, min_elements,
+ instance_id);
+ if (retval)
+ goto err_attr_init;
+ } else {
+ pr_err("Expected ACPI-package or buffer type, got: %d\n",
+ obj->type);
+ retval = -EIO;
+ goto err_attr_init;
+ }
+
+ kfree(obj);
+ instance_id++;
+ obj = hp_get_wmiobj_pointer(instance_id, guid);
+ }
+
+err_attr_init:
+ mutex_unlock(&bioscfg_drv.mutex);
+ kfree(obj);
+ return retval;
+}
+
+static int __init hp_init(void)
+{
+ int ret;
+ int hp_bios_capable = wmi_has_guid(HP_WMI_BIOS_GUID);
+ int set_bios_settings = wmi_has_guid(HP_WMI_SET_BIOS_SETTING_GUID);
+
+ if (!hp_bios_capable) {
+ pr_err("Unable to run on non-HP system\n");
+ return -ENODEV;
+ }
+
+ if (!set_bios_settings) {
+ pr_err("Unable to set BIOS settings on HP systems\n");
+ return -ENODEV;
+ }
+
+ ret = hp_init_attr_set_interface();
+ if (ret)
+ return ret;
+
+ ret = fw_attributes_class_get(&fw_attr_class);
+ if (ret)
+ goto err_unregister_class;
+
+ bioscfg_drv.class_dev = device_create(fw_attr_class, NULL, MKDEV(0, 0),
+ NULL, "%s", DRIVER_NAME);
+ if (IS_ERR(bioscfg_drv.class_dev)) {
+ ret = PTR_ERR(bioscfg_drv.class_dev);
+ goto err_unregister_class;
+ }
+
+ bioscfg_drv.main_dir_kset = kset_create_and_add("attributes", NULL,
+ &bioscfg_drv.class_dev->kobj);
+ if (!bioscfg_drv.main_dir_kset) {
+ ret = -ENOMEM;
+ pr_debug("Failed to create and add attributes\n");
+ goto err_destroy_classdev;
+ }
+
+ bioscfg_drv.authentication_dir_kset = kset_create_and_add("authentication", NULL,
+ &bioscfg_drv.class_dev->kobj);
+ if (!bioscfg_drv.authentication_dir_kset) {
+ ret = -ENOMEM;
+ pr_debug("Failed to create and add authentication\n");
+ goto err_release_attributes_data;
+ }
+
+ /*
+ * sysfs level attributes.
+ * - pending_reboot
+ */
+ ret = create_attributes_level_sysfs_files();
+ if (ret)
+ pr_debug("Failed to create sysfs level attributes\n");
+
+ ret = hp_init_bios_attributes(HPWMI_STRING_TYPE, HP_WMI_BIOS_STRING_GUID);
+ if (ret)
+ pr_debug("Failed to populate string type attributes\n");
+
+ ret = hp_init_bios_attributes(HPWMI_INTEGER_TYPE, HP_WMI_BIOS_INTEGER_GUID);
+ if (ret)
+ pr_debug("Failed to populate integer type attributes\n");
+
+ ret = hp_init_bios_attributes(HPWMI_ENUMERATION_TYPE, HP_WMI_BIOS_ENUMERATION_GUID);
+ if (ret)
+ pr_debug("Failed to populate enumeration type attributes\n");
+
+ ret = hp_init_bios_attributes(HPWMI_ORDERED_LIST_TYPE, HP_WMI_BIOS_ORDERED_LIST_GUID);
+ if (ret)
+ pr_debug("Failed to populate ordered list object type attributes\n");
+
+ ret = hp_init_bios_attributes(HPWMI_PASSWORD_TYPE, HP_WMI_BIOS_PASSWORD_GUID);
+ if (ret)
+ pr_debug("Failed to populate password object type attributes\n");
+
+ bioscfg_drv.spm_data.attr_name_kobj = NULL;
+ ret = hp_add_other_attributes(HPWMI_SECURE_PLATFORM_TYPE);
+ if (ret)
+ pr_debug("Failed to populate secure platform object type attribute\n");
+
+ bioscfg_drv.sure_start_attr_kobj = NULL;
+ ret = hp_add_other_attributes(HPWMI_SURE_START_TYPE);
+ if (ret)
+ pr_debug("Failed to populate sure start object type attribute\n");
+
+ return 0;
+
+err_release_attributes_data:
+ release_attributes_data();
+
+err_destroy_classdev:
+ device_destroy(fw_attr_class, MKDEV(0, 0));
+
+err_unregister_class:
+ fw_attributes_class_put();
+ hp_exit_attr_set_interface();
+
+ return ret;
+}
+
+static void __exit hp_exit(void)
+{
+ release_attributes_data();
+ device_destroy(fw_attr_class, MKDEV(0, 0));
+
+ fw_attributes_class_put();
+ hp_exit_attr_set_interface();
+}
+
+module_init(hp_init);
+module_exit(hp_exit);
--
2.34.1


2023-05-17 15:54:52

by Jorge Lopez

[permalink] [raw]
Subject: [PATCH v14 12/13] hp-bioscfg: Makefile

HP BIOS Configuration driver purpose is to provide a driver supporting
the latest sysfs class firmware attributes framework allowing the user
to change BIOS settings and security solutions on HP Inc.’s commercial
notebooks.

Many features of HP Commercial notebooks can be managed using Windows
Management Instrumentation (WMI). WMI is an implementation of Web-Based
Enterprise Management (WBEM) that provides a standards-based interface
for changing and monitoring system settings. HP BIOSCFG driver provides
a native Linux solution and the exposed features facilitates the
migration to Linux environments.

The Linux security features to be provided in hp-bioscfg driver enables
managing the BIOS settings and security solutions via sysfs, a virtual
filesystem that can be used by user-mode applications. The new
documentation cover HP-specific firmware sysfs attributes such Secure
Platform Management and Sure Start. Each section provides security
feature description and identifies sysfs directories and files exposed
by the driver.

Many HP Commercial notebooks include a feature called Secure Platform
Management (SPM), which replaces older password-based BIOS settings
management with public key cryptography. PC secure product management
begins when a target system is provisioned with cryptographic keys
that are used to ensure the integrity of communications between system
management utilities and the BIOS.

HP Commercial notebooks have several BIOS settings that control its
behaviour and capabilities, many of which are related to security.
To prevent unauthorized changes to these settings, the system can
be configured to use a cryptographic signature-based authorization
string that the BIOS will use to verify authorization to modify the
setting.

Linux Security components are under development and not published yet.
The only linux component is the driver (hp bioscfg) at this time.
Other published security components are under Windows.

Signed-off-by: Jorge Lopez <[email protected]>

---
Based on the latest platform-drivers-x86.git/for-next
---
drivers/platform/x86/hp/Kconfig | 16 ++++++++++++++++
drivers/platform/x86/hp/Makefile | 1 +
drivers/platform/x86/hp/hp-bioscfg/Makefile | 11 +++++++++++
3 files changed, 28 insertions(+)
create mode 100644 drivers/platform/x86/hp/hp-bioscfg/Makefile

diff --git a/drivers/platform/x86/hp/Kconfig b/drivers/platform/x86/hp/Kconfig
index ae165955311c..7fef4f12e498 100644
--- a/drivers/platform/x86/hp/Kconfig
+++ b/drivers/platform/x86/hp/Kconfig
@@ -60,4 +60,20 @@ config TC1100_WMI
This is a driver for the WMI extensions (wireless and bluetooth power
control) of the HP Compaq TC1100 tablet.

+config HP_BIOSCFG
+ tristate "HP BIOS Configuration Driver"
+ default m
+ depends on ACPI_WMI
+ select NLS
+ select FW_ATTR_CLASS
+ help
+ This driver enables administrators to securely manage BIOS settings
+ using digital certificates and public-key cryptography that eliminate
+ the need for passwords for both remote and local management. It supports
+ changing BIOS settings on many HP machines from 2018 and newer without
+ the use of any additional software.
+
+ To compile this driver as a module, choose M here: the module will
+ be called hp-bioscfg.
+
endif # X86_PLATFORM_DRIVERS_HP
diff --git a/drivers/platform/x86/hp/Makefile b/drivers/platform/x86/hp/Makefile
index db1eed4cd7c7..e4f908a61acf 100644
--- a/drivers/platform/x86/hp/Makefile
+++ b/drivers/platform/x86/hp/Makefile
@@ -8,3 +8,4 @@
obj-$(CONFIG_HP_ACCEL) += hp_accel.o
obj-$(CONFIG_HP_WMI) += hp-wmi.o
obj-$(CONFIG_TC1100_WMI) += tc1100-wmi.o
+obj-$(CONFIG_HP_BIOSCFG) += hp-bioscfg/
diff --git a/drivers/platform/x86/hp/hp-bioscfg/Makefile b/drivers/platform/x86/hp/hp-bioscfg/Makefile
new file mode 100644
index 000000000000..67be0d917753
--- /dev/null
+++ b/drivers/platform/x86/hp/hp-bioscfg/Makefile
@@ -0,0 +1,11 @@
+obj-$(CONFIG_HP_BIOSCFG) := hp-bioscfg.o
+
+hp-bioscfg-objs := bioscfg.o \
+ biosattr-interface.o \
+ enum-attributes.o \
+ int-attributes.o \
+ order-list-attributes.o \
+ passwdobj-attributes.o \
+ spmobj-attributes.o \
+ string-attributes.o \
+ surestart-attributes.o
--
2.34.1


2023-05-17 15:59:09

by Jorge Lopez

[permalink] [raw]
Subject: [PATCH v14 13/13] hp-bioscfg: MAINTAINERS

HP BIOS Configuration driver purpose is to provide a driver supporting
the latest sysfs class firmware attributes framework allowing the user
to change BIOS settings and security solutions on HP Inc.’s commercial
notebooks.

Many features of HP Commercial notebooks can be managed using Windows
Management Instrumentation (WMI). WMI is an implementation of Web-Based
Enterprise Management (WBEM) that provides a standards-based interface
for changing and monitoring system settings. HP BIOSCFG driver provides
a native Linux solution and the exposed features facilitates the
migration to Linux environments.

The Linux security features to be provided in hp-bioscfg driver enables
managing the BIOS settings and security solutions via sysfs, a virtual
filesystem that can be used by user-mode applications. The new
documentation cover HP-specific firmware sysfs attributes such Secure
Platform Management and Sure Start. Each section provides security
feature description and identifies sysfs directories and files exposed
by the driver.

Many HP Commercial notebooks include a feature called Secure Platform
Management (SPM), which replaces older password-based BIOS settings
management with public key cryptography. PC secure product management
begins when a target system is provisioned with cryptographic keys
that are used to ensure the integrity of communications between system
management utilities and the BIOS.

HP Commercial notebooks have several BIOS settings that control its
behaviour and capabilities, many of which are related to security.
To prevent unauthorized changes to these settings, the system can
be configured to use a cryptographic signature-based authorization
string that the BIOS will use to verify authorization to modify the
setting.

Linux Security components are under development and not published yet.
The only linux component is the driver (hp bioscfg) at this time.
Other published security components are under Windows.

Signed-off-by: Jorge Lopez <[email protected]>

---
Based on the latest platform-drivers-x86.git/for-next
---
MAINTAINERS | 6 ++++++
1 file changed, 6 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index 9af9ace0e348..648c986f5867 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -9436,6 +9436,12 @@ S: Obsolete
W: http://w1.fi/hostap-driver.html
F: drivers/net/wireless/intersil/hostap/

+HP BIOSCFG DRIVER
+M: Jorge Lopez <[email protected]>
+L: [email protected]
+S: Maintained
+F: drivers/platform/x86/hp/hp-bioscfg/
+
HP COMPAQ TC1100 TABLET WMI EXTRAS DRIVER
L: [email protected]
S: Orphan
--
2.34.1


2023-05-17 15:59:09

by Jorge Lopez

[permalink] [raw]
Subject: [PATCH v14 05/13] hp-bioscfg: enum-attributes

HP BIOS Configuration driver purpose is to provide a driver supporting
the latest sysfs class firmware attributes framework allowing the user
to change BIOS settings and security solutions on HP Inc.’s commercial
notebooks.

Many features of HP Commercial notebooks can be managed using Windows
Management Instrumentation (WMI). WMI is an implementation of Web-Based
Enterprise Management (WBEM) that provides a standards-based interface
for changing and monitoring system settings. HP BIOSCFG driver provides
a native Linux solution and the exposed features facilitates the
migration to Linux environments.

The Linux security features to be provided in hp-bioscfg driver enables
managing the BIOS settings and security solutions via sysfs, a virtual
filesystem that can be used by user-mode applications. The new
documentation cover HP-specific firmware sysfs attributes such Secure
Platform Management and Sure Start. Each section provides security
feature description and identifies sysfs directories and files exposed
by the driver.

Many HP Commercial notebooks include a feature called Secure Platform
Management (SPM), which replaces older password-based BIOS settings
management with public key cryptography. PC secure product management
begins when a target system is provisioned with cryptographic keys
that are used to ensure the integrity of communications between system
management utilities and the BIOS.

HP Commercial notebooks have several BIOS settings that control its
behaviour and capabilities, many of which are related to security.
To prevent unauthorized changes to these settings, the system can
be configured to use a cryptographic signature-based authorization
string that the BIOS will use to verify authorization to modify the
setting.

Linux Security components are under development and not published yet.
The only linux component is the driver (hp bioscfg) at this time.
Other published security components are under Windows.

Signed-off-by: Jorge Lopez <[email protected]>

---
Based on the latest platform-drivers-x86.git/for-next
---
.../x86/hp/hp-bioscfg/enum-attributes.c | 465 ++++++++++++++++++
1 file changed, 465 insertions(+)
create mode 100644 drivers/platform/x86/hp/hp-bioscfg/enum-attributes.c

diff --git a/drivers/platform/x86/hp/hp-bioscfg/enum-attributes.c b/drivers/platform/x86/hp/hp-bioscfg/enum-attributes.c
new file mode 100644
index 000000000000..80842835606d
--- /dev/null
+++ b/drivers/platform/x86/hp/hp-bioscfg/enum-attributes.c
@@ -0,0 +1,465 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Functions corresponding to enumeration type attributes under
+ * BIOS Enumeration GUID for use with hp-bioscfg driver.
+ *
+ * Copyright (c) 2022 HP Development Company, L.P.
+ */
+
+#include "bioscfg.h"
+
+GET_INSTANCE_ID(enumeration);
+
+static ssize_t current_value_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
+{
+ int instance_id = get_enumeration_instance_id(kobj);
+
+ if (instance_id < 0)
+ return -EIO;
+
+ return sysfs_emit(buf, "%s\n",
+ bioscfg_drv.enumeration_data[instance_id].current_value);
+}
+
+/**
+ * validate_enumeration_input() -
+ * Validate input of current_value against possible values
+ *
+ * @instance_id: The instance on which input is validated
+ * @buf: Input value
+ */
+static int validate_enumeration_input(int instance_id, const char *buf)
+{
+ int i;
+ int found = 0;
+ struct enumeration_data *enum_data = &bioscfg_drv.enumeration_data[instance_id];
+
+ /* Is it a read only attribute */
+ if (enum_data->common.is_readonly)
+ return -EIO;
+
+ for (i = 0; i < enum_data->possible_values_size && !found; i++)
+ if (!strcmp(enum_data->possible_values[i], buf))
+ found = 1;
+
+ if (!found)
+ return -EINVAL;
+
+ return 0;
+}
+
+static void update_enumeration_value(int instance_id, char *attr_value)
+{
+ struct enumeration_data *enum_data = &bioscfg_drv.enumeration_data[instance_id];
+
+ strscpy(enum_data->current_value,
+ attr_value,
+ sizeof(enum_data->current_value));
+}
+
+ATTRIBUTE_S_COMMON_PROPERTY_SHOW(display_name, enumeration);
+static struct kobj_attribute enumeration_display_name =
+ __ATTR_RO(display_name);
+
+ATTRIBUTE_PROPERTY_STORE(current_value, enumeration);
+static struct kobj_attribute enumeration_current_val =
+ __ATTR_RW(current_value);
+
+ATTRIBUTE_VALUES_PROPERTY_SHOW(possible_values, enumeration, SEMICOLON_SEP);
+static struct kobj_attribute enumeration_poss_val =
+ __ATTR_RO(possible_values);
+
+static ssize_t type_show(struct kobject *kobj, struct kobj_attribute *attr,
+ char *buf)
+{
+ return sysfs_emit(buf, "enumeration\n");
+}
+
+static struct kobj_attribute enumeration_type =
+ __ATTR_RO(type);
+
+static struct kobj_attribute common_display_langcode =
+ __ATTR_RO(display_name_language_code);
+
+static struct attribute *enumeration_attrs[] = {
+ &common_display_langcode.attr,
+ &enumeration_display_name.attr,
+ &enumeration_current_val.attr,
+ &enumeration_poss_val.attr,
+ &enumeration_type.attr,
+ NULL
+};
+
+static const struct attribute_group enumeration_attr_group = {
+ .attrs = enumeration_attrs,
+};
+
+int hp_alloc_enumeration_data(void)
+{
+ bioscfg_drv.enumeration_instances_count =
+ hp_get_instance_count(HP_WMI_BIOS_ENUMERATION_GUID);
+
+ bioscfg_drv.enumeration_data = kcalloc(bioscfg_drv.enumeration_instances_count,
+ sizeof(*bioscfg_drv.enumeration_data), GFP_KERNEL);
+ if (!bioscfg_drv.enumeration_data) {
+ bioscfg_drv.enumeration_instances_count = 0;
+ return -ENOMEM;
+ }
+ return 0;
+}
+
+/* Expected Values types associated with each element */
+static const acpi_object_type expected_enum_types[] = {
+ [NAME] = ACPI_TYPE_STRING,
+ [VALUE] = ACPI_TYPE_STRING,
+ [PATH] = ACPI_TYPE_STRING,
+ [IS_READONLY] = ACPI_TYPE_INTEGER,
+ [DISPLAY_IN_UI] = ACPI_TYPE_INTEGER,
+ [REQUIRES_PHYSICAL_PRESENCE] = ACPI_TYPE_INTEGER,
+ [SEQUENCE] = ACPI_TYPE_INTEGER,
+ [PREREQUISITES_SIZE] = ACPI_TYPE_INTEGER,
+ [PREREQUISITES] = ACPI_TYPE_STRING,
+ [SECURITY_LEVEL] = ACPI_TYPE_INTEGER,
+ [ENUM_CURRENT_VALUE] = ACPI_TYPE_STRING,
+ [ENUM_SIZE] = ACPI_TYPE_INTEGER,
+ [ENUM_POSSIBLE_VALUES] = ACPI_TYPE_STRING,
+};
+
+static int hp_populate_enumeration_elements_from_package(union acpi_object *enum_obj,
+ int enum_obj_count,
+ int instance_id)
+{
+ char *str_value = NULL;
+ int value_len;
+ u32 size = 0;
+ u32 int_value;
+ int elem = 0;
+ int reqs;
+ int pos_values;
+ int ret;
+ int eloc;
+ struct enumeration_data *enum_data = &bioscfg_drv.enumeration_data[instance_id];
+
+ for (elem = 1, eloc = 1; elem < enum_obj_count; elem++, eloc++) {
+ /* ONLY look at the first ENUM_ELEM_CNT elements */
+ if (eloc == ENUM_ELEM_CNT)
+ goto exit_enumeration_package;
+
+ switch (enum_obj[elem].type) {
+ case ACPI_TYPE_STRING:
+ if (PREREQUISITES != elem && ENUM_POSSIBLE_VALUES != elem) {
+ ret = hp_convert_hexstr_to_str(enum_obj[elem].string.pointer,
+ enum_obj[elem].string.length,
+ &str_value, &value_len);
+ if (ret)
+ return -EINVAL;
+ }
+ break;
+ case ACPI_TYPE_INTEGER:
+ int_value = (u32)enum_obj[elem].integer.value;
+ break;
+ default:
+ pr_warn("Unsupported object type [%d]\n", enum_obj[elem].type);
+ continue;
+ }
+
+ /* Check that both expected and read object type match */
+ if (expected_enum_types[eloc] != enum_obj[elem].type) {
+ pr_err("Error expected type %d for elem %d, but got type %d instead\n",
+ expected_enum_types[eloc], elem, enum_obj[elem].type);
+ return -EIO;
+ }
+
+ /* Assign appropriate element value to corresponding field */
+ switch (eloc) {
+ case NAME:
+ case VALUE:
+ break;
+ case PATH:
+ strscpy(enum_data->common.path, str_value,
+ sizeof(enum_data->common.path));
+ break;
+ case IS_READONLY:
+ enum_data->common.is_readonly = int_value;
+ break;
+ case DISPLAY_IN_UI:
+ enum_data->common.display_in_ui = int_value;
+ break;
+ case REQUIRES_PHYSICAL_PRESENCE:
+ enum_data->common.requires_physical_presence = int_value;
+ break;
+ case SEQUENCE:
+ enum_data->common.sequence = int_value;
+ break;
+ case PREREQUISITES_SIZE:
+ enum_data->common.prerequisites_size = int_value;
+ if (int_value > MAX_PREREQUISITES_SIZE)
+ pr_warn("Prerequisites size value exceeded the maximum number of elements supported or data may be malformed\n");
+
+ /*
+ * This HACK is needed to keep the expected
+ * element list pointing to the right obj[elem].type
+ * when the size is zero. PREREQUISITES
+ * object is omitted by BIOS when the size is
+ * zero.
+ */
+ if (int_value == 0)
+ eloc++;
+ break;
+
+ case PREREQUISITES:
+ size = min_t(u32, enum_data->common.prerequisites_size, MAX_PREREQUISITES_SIZE);
+ for (reqs = 0; reqs < size; reqs++) {
+ if (elem >= enum_obj_count) {
+ pr_err("Error enum-objects package is too small\n");
+ return -EINVAL;
+ }
+
+ ret = hp_convert_hexstr_to_str(enum_obj[elem + reqs].string.pointer,
+ enum_obj[elem + reqs].string.length,
+ &str_value, &value_len);
+
+ if (ret)
+ return -EINVAL;
+
+ strscpy(enum_data->common.prerequisites[reqs],
+ str_value,
+ sizeof(enum_data->common.prerequisites[reqs]));
+
+ kfree(str_value);
+ }
+ break;
+
+ case SECURITY_LEVEL:
+ enum_data->common.security_level = int_value;
+ break;
+
+ case ENUM_CURRENT_VALUE:
+ strscpy(enum_data->current_value,
+ str_value, sizeof(enum_data->current_value));
+ break;
+ case ENUM_SIZE:
+ enum_data->possible_values_size = int_value;
+ if (int_value > MAX_VALUES_SIZE)
+ pr_warn("Possible number values size value exceeded the maximum number of elements supported or data may be malformed\n");
+
+ /*
+ * This HACK is needed to keep the expected
+ * element list pointing to the right obj[elem].type
+ * when the size is zero. POSSIBLE_VALUES
+ * object is omitted by BIOS when the size is zero.
+ */
+ if (int_value == 0)
+ eloc++;
+ break;
+
+ case ENUM_POSSIBLE_VALUES:
+ size = enum_data->possible_values_size;
+
+ for (pos_values = 0; pos_values < size && pos_values < MAX_VALUES_SIZE;
+ pos_values++) {
+ if (elem >= enum_obj_count) {
+ pr_err("Error enum-objects package is too small\n");
+ return -EINVAL;
+ }
+
+ ret = hp_convert_hexstr_to_str(enum_obj[elem + pos_values].string.pointer,
+ enum_obj[elem + pos_values].string.length,
+ &str_value, &value_len);
+
+ if (ret)
+ return -EINVAL;
+
+ /*
+ * ignore strings when possible values size
+ * is greater than MAX_VALUES_SIZE
+ */
+ if (size < MAX_VALUES_SIZE)
+ strscpy(enum_data->possible_values[pos_values],
+ str_value,
+ sizeof(enum_data->possible_values[pos_values]));
+ }
+ break;
+ default:
+ pr_warn("Invalid element: %d found in Enumeration attribute or data may be malformed\n", elem);
+ break;
+ }
+
+ kfree(str_value);
+ }
+
+exit_enumeration_package:
+ kfree(str_value);
+ return 0;
+}
+
+/**
+ * hp_populate_enumeration_package_data() -
+ * Populate all properties of an instance under enumeration attribute
+ *
+ * @enum_obj: ACPI object with enumeration data
+ * @instance_id: The instance to enumerate
+ * @attr_name_kobj: The parent kernel object
+ */
+int hp_populate_enumeration_package_data(union acpi_object *enum_obj,
+ int instance_id,
+ struct kobject *attr_name_kobj)
+{
+ struct enumeration_data *enum_data = &bioscfg_drv.enumeration_data[instance_id];
+
+ enum_data->attr_name_kobj = attr_name_kobj;
+
+ hp_populate_enumeration_elements_from_package(enum_obj,
+ enum_obj->package.count,
+ instance_id);
+ hp_update_attribute_permissions(enum_data->common.is_readonly,
+ &enumeration_current_val);
+ /*
+ * Several attributes have names such "MONDAY". Friendly
+ * user nane is generated to make the name more descriptive
+ */
+ hp_friendly_user_name_update(enum_data->common.path,
+ attr_name_kobj->name,
+ enum_data->common.display_name,
+ sizeof(enum_data->common.display_name));
+ return sysfs_create_group(attr_name_kobj, &enumeration_attr_group);
+}
+
+static int hp_populate_enumeration_elements_from_buffer(u8 *buffer_ptr, u32 *buffer_size,
+ int instance_id)
+{
+ int reqs;
+ int values;
+ struct enumeration_data *enum_data = &bioscfg_drv.enumeration_data[instance_id];
+
+ /*
+ * In earlier implementation, reported errors were ignored
+ * causing the data to remain uninitialized. It is for this
+ * reason functions may return an error and no validation
+ * takes place.
+ */
+
+ // VALUE:
+ hp_get_string_from_buffer(&buffer_ptr, buffer_size, enum_data->current_value,
+ sizeof(enum_data->current_value));
+
+ // PATH:
+ hp_get_string_from_buffer(&buffer_ptr, buffer_size, enum_data->common.path,
+ sizeof(enum_data->common.path));
+
+ // IS_READONLY:
+ hp_get_integer_from_buffer(&buffer_ptr, buffer_size,
+ &enum_data->common.is_readonly);
+
+ //DISPLAY_IN_UI:
+ hp_get_integer_from_buffer(&buffer_ptr, buffer_size,
+ &enum_data->common.display_in_ui);
+
+ // REQUIRES_PHYSICAL_PRESENCE:
+ hp_get_integer_from_buffer(&buffer_ptr, buffer_size,
+ &enum_data->common.requires_physical_presence);
+
+ // SEQUENCE:
+ hp_get_integer_from_buffer(&buffer_ptr, buffer_size,
+ &enum_data->common.sequence);
+
+ // PREREQUISITES_SIZE:
+ hp_get_integer_from_buffer(&buffer_ptr, buffer_size,
+ &enum_data->common.prerequisites_size);
+
+ if (enum_data->common.prerequisites_size > MAX_PREREQUISITES_SIZE) {
+ /* Report a message and limit prerequisite size to maximum value */
+ pr_warn("Enum Prerequisites size value exceeded the maximum number of elements supported or data may be malformed\n");
+ enum_data->common.prerequisites_size = MAX_PREREQUISITES_SIZE;
+ }
+
+ // PREREQUISITES:
+ for (reqs = 0; reqs < enum_data->common.prerequisites_size; reqs++)
+ hp_get_string_from_buffer(&buffer_ptr, buffer_size,
+ enum_data->common.prerequisites[reqs],
+ sizeof(enum_data->common.prerequisites[reqs]));
+
+ // SECURITY_LEVEL:
+ hp_get_integer_from_buffer(&buffer_ptr, buffer_size,
+ &enum_data->common.security_level);
+
+ // ENUM_CURRENT_VALUE:
+ hp_get_string_from_buffer(&buffer_ptr, buffer_size,
+ enum_data->current_value,
+ sizeof(enum_data->current_value));
+ // ENUM_SIZE:
+ hp_get_integer_from_buffer(&buffer_ptr, buffer_size,
+ &enum_data->possible_values_size);
+
+ if (enum_data->possible_values_size > MAX_VALUES_SIZE) {
+ /* Report a message and limit possible values size to maximum value */
+ pr_warn("Enum Possible size value exceeded the maximum number of elements supported or data may be malformed\n");
+ enum_data->possible_values_size = MAX_VALUES_SIZE;
+ }
+
+ // ENUM_POSSIBLE_VALUES:
+
+ for (values = 0; values < enum_data->possible_values_size; values++)
+ hp_get_string_from_buffer(&buffer_ptr, buffer_size,
+ enum_data->possible_values[values],
+ sizeof(enum_data->possible_values[values]));
+
+ return 0;
+}
+
+/**
+ * hp_populate_enumeration_buffer_data() -
+ * Populate all properties of an instance under enumeration attribute
+ *
+ * @buffer_ptr: Buffer pointer
+ * @buffer_size: Buffer size
+ * @instance_id: The instance to enumerate
+ * @attr_name_kobj: The parent kernel object
+ */
+int hp_populate_enumeration_buffer_data(u8 *buffer_ptr, u32 *buffer_size,
+ int instance_id,
+ struct kobject *attr_name_kobj)
+{
+ struct enumeration_data *enum_data = &bioscfg_drv.enumeration_data[instance_id];
+
+ enum_data->attr_name_kobj = attr_name_kobj;
+
+ /* Populate enumeration elements */
+ hp_populate_enumeration_elements_from_buffer(buffer_ptr, buffer_size, instance_id);
+
+ hp_update_attribute_permissions(enum_data->common.is_readonly,
+ &enumeration_current_val);
+ /*
+ * Several attributes have names such "MONDAY". A Friendlier
+ * user nane is generated to make the name more descriptive
+ */
+ hp_friendly_user_name_update(enum_data->common.path,
+ attr_name_kobj->name,
+ enum_data->common.display_name,
+ sizeof(enum_data->common.display_name));
+
+ return sysfs_create_group(attr_name_kobj, &enumeration_attr_group);
+}
+
+/**
+ * hp_exit_enumeration_attributes() - Clear all attribute data
+ *
+ * Clears all data allocated for this group of attributes
+ */
+void hp_exit_enumeration_attributes(void)
+{
+ int instance_id;
+
+ for (instance_id = 0; instance_id < bioscfg_drv.enumeration_instances_count;
+ instance_id++) {
+ struct enumeration_data *enum_data = &bioscfg_drv.enumeration_data[instance_id];
+ struct kobject *attr_name_kobj = enum_data->attr_name_kobj;
+
+ if (attr_name_kobj)
+ sysfs_remove_group(attr_name_kobj, &enumeration_attr_group);
+ }
+ bioscfg_drv.enumeration_instances_count = 0;
+
+ kfree(bioscfg_drv.enumeration_data);
+ bioscfg_drv.enumeration_data = NULL;
+}
--
2.34.1


2023-05-17 15:59:21

by Jorge Lopez

[permalink] [raw]
Subject: [PATCH v14 06/13] hp-bioscfg: int-attributes

HP BIOS Configuration driver purpose is to provide a driver supporting
the latest sysfs class firmware attributes framework allowing the user
to change BIOS settings and security solutions on HP Inc.’s commercial
notebooks.

Many features of HP Commercial notebooks can be managed using Windows
Management Instrumentation (WMI). WMI is an implementation of Web-Based
Enterprise Management (WBEM) that provides a standards-based interface
for changing and monitoring system settings. HP BIOSCFG driver provides
a native Linux solution and the exposed features facilitates the
migration to Linux environments.

The Linux security features to be provided in hp-bioscfg driver enables
managing the BIOS settings and security solutions via sysfs, a virtual
filesystem that can be used by user-mode applications. The new
documentation cover HP-specific firmware sysfs attributes such Secure
Platform Management and Sure Start. Each section provides security
feature description and identifies sysfs directories and files exposed
by the driver.

Many HP Commercial notebooks include a feature called Secure Platform
Management (SPM), which replaces older password-based BIOS settings
management with public key cryptography. PC secure product management
begins when a target system is provisioned with cryptographic keys
that are used to ensure the integrity of communications between system
management utilities and the BIOS.

HP Commercial notebooks have several BIOS settings that control its
behaviour and capabilities, many of which are related to security.
To prevent unauthorized changes to these settings, the system can
be configured to use a cryptographic signature-based authorization
string that the BIOS will use to verify authorization to modify the
setting.

Linux Security components are under development and not published yet.
The only linux component is the driver (hp bioscfg) at this time.
Other published security components are under Windows.

Signed-off-by: Jorge Lopez <[email protected]>

---
Based on the latest platform-drivers-x86.git/for-next
---
.../x86/hp/hp-bioscfg/int-attributes.c | 440 ++++++++++++++++++
1 file changed, 440 insertions(+)
create mode 100644 drivers/platform/x86/hp/hp-bioscfg/int-attributes.c

diff --git a/drivers/platform/x86/hp/hp-bioscfg/int-attributes.c b/drivers/platform/x86/hp/hp-bioscfg/int-attributes.c
new file mode 100644
index 000000000000..8a3836bd2430
--- /dev/null
+++ b/drivers/platform/x86/hp/hp-bioscfg/int-attributes.c
@@ -0,0 +1,440 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Functions corresponding to integer type attributes under
+ * BIOS Enumeration GUID for use with hp-bioscfg driver.
+ *
+ * Copyright (c) 2022 Hewlett-Packard Inc.
+ */
+
+#include "bioscfg.h"
+
+GET_INSTANCE_ID(integer);
+
+static ssize_t current_value_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
+{
+ int instance_id = get_integer_instance_id(kobj);
+
+ if (instance_id < 0)
+ return -EIO;
+
+ return sysfs_emit(buf, "%d\n",
+ bioscfg_drv.integer_data[instance_id].current_value);
+}
+
+/**
+ * validate_integer_input() -
+ * Validate input of current_value against lower and upper bound
+ *
+ * @instance_id: The instance on which input is validated
+ * @buf: Input value
+ */
+static int validate_integer_input(int instance_id, char *buf)
+{
+ int in_val;
+ int ret;
+ struct integer_data *integer_data = &bioscfg_drv.integer_data[instance_id];
+
+ /* BIOS treats it as a read only attribute */
+ if (integer_data->common.is_readonly)
+ return -EIO;
+
+ ret = kstrtoint(buf, 10, &in_val);
+ if (ret < 0)
+ return ret;
+
+ if (in_val < integer_data->lower_bound ||
+ in_val > integer_data->upper_bound)
+ return -ERANGE;
+
+ return 0;
+}
+
+static void update_integer_value(int instance_id, char *attr_value)
+{
+ int in_val;
+ int ret;
+ struct integer_data *integer_data = &bioscfg_drv.integer_data[instance_id];
+
+ ret = kstrtoint(attr_value, 10, &in_val);
+ if (ret == 0)
+ integer_data->current_value = in_val;
+ else
+ pr_warn("Invalid integer value found: %s\n", attr_value);
+}
+
+ATTRIBUTE_S_COMMON_PROPERTY_SHOW(display_name, integer);
+static struct kobj_attribute integer_display_name =
+ __ATTR_RO(display_name);
+
+ATTRIBUTE_PROPERTY_STORE(current_value, integer);
+static struct kobj_attribute integer_current_val =
+ __ATTR_RW_MODE(current_value, 0644);
+
+ATTRIBUTE_N_PROPERTY_SHOW(lower_bound, integer);
+static struct kobj_attribute integer_lower_bound =
+ __ATTR_RO(lower_bound);
+
+ATTRIBUTE_N_PROPERTY_SHOW(upper_bound, integer);
+static struct kobj_attribute integer_upper_bound =
+ __ATTR_RO(upper_bound);
+
+ATTRIBUTE_N_PROPERTY_SHOW(scalar_increment, integer);
+static struct kobj_attribute integer_scalar_increment =
+ __ATTR_RO(scalar_increment);
+
+static ssize_t type_show(struct kobject *kobj, struct kobj_attribute *attr,
+ char *buf)
+{
+ return sysfs_emit(buf, "integer\n");
+}
+
+static struct kobj_attribute integer_type =
+ __ATTR_RO(type);
+
+static struct kobj_attribute common_display_langcode =
+ __ATTR_RO(display_name_language_code);
+
+static struct attribute *integer_attrs[] = {
+ &common_display_langcode.attr,
+ &integer_display_name.attr,
+ &integer_current_val.attr,
+ &integer_lower_bound.attr,
+ &integer_upper_bound.attr,
+ &integer_scalar_increment.attr,
+ &integer_type.attr,
+ NULL
+};
+
+static const struct attribute_group integer_attr_group = {
+ .attrs = integer_attrs,
+};
+
+int hp_alloc_integer_data(void)
+{
+ bioscfg_drv.integer_instances_count = hp_get_instance_count(HP_WMI_BIOS_INTEGER_GUID);
+ bioscfg_drv.integer_data = kcalloc(bioscfg_drv.integer_instances_count,
+ sizeof(*bioscfg_drv.integer_data), GFP_KERNEL);
+
+ if (!bioscfg_drv.integer_data) {
+ bioscfg_drv.integer_instances_count = 0;
+ return -ENOMEM;
+ }
+ return 0;
+}
+
+/* Expected Values types associated with each element */
+static const acpi_object_type expected_integer_types[] = {
+ [NAME] = ACPI_TYPE_STRING,
+ [VALUE] = ACPI_TYPE_STRING,
+ [PATH] = ACPI_TYPE_STRING,
+ [IS_READONLY] = ACPI_TYPE_INTEGER,
+ [DISPLAY_IN_UI] = ACPI_TYPE_INTEGER,
+ [REQUIRES_PHYSICAL_PRESENCE] = ACPI_TYPE_INTEGER,
+ [SEQUENCE] = ACPI_TYPE_INTEGER,
+ [PREREQUISITES_SIZE] = ACPI_TYPE_INTEGER,
+ [PREREQUISITES] = ACPI_TYPE_STRING,
+ [SECURITY_LEVEL] = ACPI_TYPE_INTEGER,
+ [INT_LOWER_BOUND] = ACPI_TYPE_INTEGER,
+ [INT_UPPER_BOUND] = ACPI_TYPE_INTEGER,
+ [INT_SCALAR_INCREMENT] = ACPI_TYPE_INTEGER,
+};
+
+static int hp_populate_integer_elements_from_package(union acpi_object *integer_obj,
+ int integer_obj_count,
+ int instance_id)
+{
+ char *str_value = NULL;
+ int value_len;
+ int ret;
+ u32 int_value;
+ int elem;
+ int reqs;
+ int eloc;
+ int size;
+ struct integer_data *integer_data = &bioscfg_drv.integer_data[instance_id];
+
+ if (!integer_obj)
+ return -EINVAL;
+
+ for (elem = 1, eloc = 1; elem < integer_obj_count; elem++, eloc++) {
+ /* ONLY look at the first INTEGER_ELEM_CNT elements */
+ if (eloc == INT_ELEM_CNT)
+ goto exit_integer_package;
+
+ switch (integer_obj[elem].type) {
+ case ACPI_TYPE_STRING:
+ if (elem != PREREQUISITES) {
+ ret = hp_convert_hexstr_to_str(integer_obj[elem].string.pointer,
+ integer_obj[elem].string.length,
+ &str_value, &value_len);
+ if (ret)
+ continue;
+ }
+ break;
+ case ACPI_TYPE_INTEGER:
+ int_value = (u32)integer_obj[elem].integer.value;
+ break;
+ default:
+ pr_warn("Unsupported object type [%d]\n", integer_obj[elem].type);
+ continue;
+ }
+ /* Check that both expected and read object type match */
+ if (expected_integer_types[eloc] != integer_obj[elem].type) {
+ pr_err("Error expected type %d for elem %d, but got type %d instead\n",
+ expected_integer_types[eloc], elem, integer_obj[elem].type);
+ return -EIO;
+ }
+ /* Assign appropriate element value to corresponding field*/
+ switch (eloc) {
+ case VALUE:
+ ret = kstrtoint(str_value, 10, &int_value);
+ if (ret)
+ continue;
+
+ integer_data->current_value = int_value;
+ break;
+ case PATH:
+ strscpy(integer_data->common.path, str_value,
+ sizeof(integer_data->common.path));
+ break;
+ case IS_READONLY:
+ integer_data->common.is_readonly = int_value;
+ break;
+ case DISPLAY_IN_UI:
+ integer_data->common.display_in_ui = int_value;
+ break;
+ case REQUIRES_PHYSICAL_PRESENCE:
+ integer_data->common.requires_physical_presence = int_value;
+ break;
+ case SEQUENCE:
+ integer_data->common.sequence = int_value;
+ break;
+ case PREREQUISITES_SIZE:
+ if (integer_data->common.prerequisites_size > MAX_PREREQUISITES_SIZE)
+ pr_warn("Prerequisites size value exceeded the maximum number of elements supported or data may be malformed\n");
+ /*
+ * This HACK is needed to keep the expected
+ * element list pointing to the right obj[elem].type
+ * when the size is zero. PREREQUISITES
+ * object is omitted by BIOS when the size is
+ * zero.
+ */
+ if (integer_data->common.prerequisites_size == 0)
+ eloc++;
+ break;
+ case PREREQUISITES:
+ size = min_t(u32, integer_data->common.prerequisites_size, MAX_PREREQUISITES_SIZE);
+
+ for (reqs = 0; reqs < size; reqs++) {
+ if (elem >= integer_obj_count) {
+ pr_err("Error elem-objects package is too small\n");
+ return -EINVAL;
+ }
+
+ ret = hp_convert_hexstr_to_str(integer_obj[elem + reqs].string.pointer,
+ integer_obj[elem + reqs].string.length,
+ &str_value, &value_len);
+
+ if (ret)
+ continue;
+
+ strscpy(integer_data->common.prerequisites[reqs],
+ str_value,
+ sizeof(integer_data->common.prerequisites[reqs]));
+ kfree(str_value);
+ }
+ break;
+
+ case SECURITY_LEVEL:
+ integer_data->common.security_level = int_value;
+ break;
+ case INT_LOWER_BOUND:
+ integer_data->lower_bound = int_value;
+ break;
+ case INT_UPPER_BOUND:
+ integer_data->upper_bound = int_value;
+ break;
+ case INT_SCALAR_INCREMENT:
+ integer_data->scalar_increment = int_value;
+ break;
+ default:
+ pr_warn("Invalid element: %d found in Integer attribute or data may be malformed\n", elem);
+ break;
+ }
+ }
+exit_integer_package:
+ kfree(str_value);
+ return 0;
+}
+
+/**
+ * hp_populate_integer_package_data() -
+ * Populate all properties of an instance under integer attribute
+ *
+ * @integer_obj: ACPI object with integer data
+ * @instance_id: The instance to enumerate
+ * @attr_name_kobj: The parent kernel object
+ */
+int hp_populate_integer_package_data(union acpi_object *integer_obj,
+ int instance_id,
+ struct kobject *attr_name_kobj)
+{
+ struct integer_data *integer_data = &bioscfg_drv.integer_data[instance_id];
+
+ integer_data->attr_name_kobj = attr_name_kobj;
+ hp_populate_integer_elements_from_package(integer_obj,
+ integer_obj->package.count,
+ instance_id);
+ hp_update_attribute_permissions(integer_data->common.is_readonly,
+ &integer_current_val);
+ hp_friendly_user_name_update(integer_data->common.path,
+ attr_name_kobj->name,
+ integer_data->common.display_name,
+ sizeof(integer_data->common.display_name));
+ return sysfs_create_group(attr_name_kobj, &integer_attr_group);
+}
+
+static int hp_populate_integer_elements_from_buffer(u8 *buffer_ptr, u32 *buffer_size,
+ int instance_id)
+{
+ char *dst = NULL;
+ int reqs;
+ int ret;
+ int dst_size = *buffer_size / sizeof(u16);
+ struct integer_data *integer_data = &bioscfg_drv.integer_data[instance_id];
+
+ dst = kcalloc(dst_size, sizeof(char), GFP_KERNEL);
+ if (!dst)
+ return -ENOMEM;
+
+ /*
+ * Only data relevant to this driver and its functionality is
+ * read. BIOS defines the order in which each * element is
+ * read. Element 0 data is not relevant to this
+ * driver hence it is ignored. For clarity, all element names
+ * (DISPLAY_IN_UI) which defines the order in which is read
+ * and the name matches the variable where the data is stored.
+ */
+
+ /*
+ * In earlier implementation, reported errors were ignored
+ * causing the data to remain uninitialized. It is for this
+ * reason functions may return an error and no validation
+ * takes place.
+ */
+
+ // VALUE:
+ integer_data->current_value = 0;
+
+ hp_get_string_from_buffer(&buffer_ptr, buffer_size, dst, dst_size);
+ ret = kstrtoint(dst, 10, &integer_data->current_value);
+ if (ret)
+ pr_warn("Unable to convert string to integer: %s\n", dst);
+ kfree(dst);
+
+ // PATH:
+ hp_get_string_from_buffer(&buffer_ptr, buffer_size, integer_data->common.path,
+ sizeof(integer_data->common.path));
+
+ // IS_READONLY:
+ hp_get_integer_from_buffer(&buffer_ptr, buffer_size,
+ &integer_data->common.is_readonly);
+
+ //DISPLAY_IN_UI:
+ hp_get_integer_from_buffer(&buffer_ptr, buffer_size,
+ &integer_data->common.display_in_ui);
+
+ // REQUIRES_PHYSICAL_PRESENCE:
+ hp_get_integer_from_buffer(&buffer_ptr, buffer_size,
+ &integer_data->common.requires_physical_presence);
+
+ // SEQUENCE:
+ hp_get_integer_from_buffer(&buffer_ptr, buffer_size,
+ &integer_data->common.sequence);
+
+ // PREREQUISITES_SIZE:
+ hp_get_integer_from_buffer(&buffer_ptr, buffer_size,
+ &integer_data->common.prerequisites_size);
+
+ if (integer_data->common.prerequisites_size > MAX_PREREQUISITES_SIZE) {
+ /* Report a message and limit prerequisite size to maximum value */
+ pr_warn("Integer Prerequisites size value exceeded the maximum number of elements supported or data may be malformed\n");
+ integer_data->common.prerequisites_size = MAX_PREREQUISITES_SIZE;
+ }
+
+ // PREREQUISITES:
+ for (reqs = 0; reqs < integer_data->common.prerequisites_size; reqs++)
+ hp_get_string_from_buffer(&buffer_ptr, buffer_size,
+ integer_data->common.prerequisites[reqs],
+ sizeof(integer_data->common.prerequisites[reqs]));
+
+ // SECURITY_LEVEL:
+ hp_get_integer_from_buffer(&buffer_ptr, buffer_size,
+ &integer_data->common.security_level);
+
+ // INT_LOWER_BOUND:
+ hp_get_integer_from_buffer(&buffer_ptr, buffer_size,
+ &integer_data->lower_bound);
+
+ // INT_UPPER_BOUND:
+ hp_get_integer_from_buffer(&buffer_ptr, buffer_size,
+ &integer_data->upper_bound);
+
+ // INT_SCALAR_INCREMENT:
+ hp_get_integer_from_buffer(&buffer_ptr, buffer_size,
+ &integer_data->scalar_increment);
+
+ return 0;
+}
+
+/**
+ * hp_populate_integer_buffer_data() -
+ * Populate all properties of an instance under integer attribute
+ *
+ * @buffer_ptr: Buffer pointer
+ * @buffer_size: Buffer size
+ * @instance_id: The instance to enumerate
+ * @attr_name_kobj: The parent kernel object
+ */
+int hp_populate_integer_buffer_data(u8 *buffer_ptr, u32 *buffer_size, int instance_id,
+ struct kobject *attr_name_kobj)
+{
+ struct integer_data *integer_data = &bioscfg_drv.integer_data[instance_id];
+
+ integer_data->attr_name_kobj = attr_name_kobj;
+
+ /* Populate integer elements */
+ hp_populate_integer_elements_from_buffer(buffer_ptr, buffer_size,
+ instance_id);
+ hp_update_attribute_permissions(integer_data->common.is_readonly,
+ &integer_current_val);
+ hp_friendly_user_name_update(integer_data->common.path,
+ attr_name_kobj->name,
+ integer_data->common.display_name,
+ sizeof(integer_data->common.display_name));
+
+ return sysfs_create_group(attr_name_kobj, &integer_attr_group);
+}
+
+/**
+ * hp_exit_integer_attributes() - Clear all attribute data
+ *
+ * Clears all data allocated for this group of attributes
+ */
+void hp_exit_integer_attributes(void)
+{
+ int instance_id;
+
+ for (instance_id = 0; instance_id < bioscfg_drv.integer_instances_count;
+ instance_id++) {
+ struct kobject *attr_name_kobj =
+ bioscfg_drv.integer_data[instance_id].attr_name_kobj;
+
+ if (attr_name_kobj)
+ sysfs_remove_group(attr_name_kobj, &integer_attr_group);
+ }
+ bioscfg_drv.integer_instances_count = 0;
+
+ kfree(bioscfg_drv.integer_data);
+ bioscfg_drv.integer_data = NULL;
+}
--
2.34.1


2023-05-17 15:59:30

by Jorge Lopez

[permalink] [raw]
Subject: [PATCH v14 09/13] hp-bioscfg: spmobj-attributes

HP BIOS Configuration driver purpose is to provide a driver supporting
the latest sysfs class firmware attributes framework allowing the user
to change BIOS settings and security solutions on HP Inc.’s commercial
notebooks.

Many features of HP Commercial notebooks can be managed using Windows
Management Instrumentation (WMI). WMI is an implementation of Web-Based
Enterprise Management (WBEM) that provides a standards-based interface
for changing and monitoring system settings. HP BIOSCFG driver provides
a native Linux solution and the exposed features facilitates the
migration to Linux environments.

The Linux security features to be provided in hp-bioscfg driver enables
managing the BIOS settings and security solutions via sysfs, a virtual
filesystem that can be used by user-mode applications. The new
documentation cover HP-specific firmware sysfs attributes such Secure
Platform Management and Sure Start. Each section provides security
feature description and identifies sysfs directories and files exposed
by the driver.

Many HP Commercial notebooks include a feature called Secure Platform
Management (SPM), which replaces older password-based BIOS settings
management with public key cryptography. PC secure product management
begins when a target system is provisioned with cryptographic keys
that are used to ensure the integrity of communications between system
management utilities and the BIOS.

HP Commercial notebooks have several BIOS settings that control its
behaviour and capabilities, many of which are related to security.
To prevent unauthorized changes to these settings, the system can
be configured to use a cryptographic signature-based authorization
string that the BIOS will use to verify authorization to modify the
setting.

Linux Security components are under development and not published yet.
The only linux component is the driver (hp bioscfg) at this time.
Other published security components are under Windows.

Signed-off-by: Jorge Lopez <[email protected]>

---
Based on the latest platform-drivers-x86.git/for-next
---
.../x86/hp/hp-bioscfg/spmobj-attributes.c | 389 ++++++++++++++++++
1 file changed, 389 insertions(+)
create mode 100644 drivers/platform/x86/hp/hp-bioscfg/spmobj-attributes.c

diff --git a/drivers/platform/x86/hp/hp-bioscfg/spmobj-attributes.c b/drivers/platform/x86/hp/hp-bioscfg/spmobj-attributes.c
new file mode 100644
index 000000000000..66f025b5d113
--- /dev/null
+++ b/drivers/platform/x86/hp/hp-bioscfg/spmobj-attributes.c
@@ -0,0 +1,389 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Functions corresponding to secure platform management object type
+ * attributes under BIOS PASSWORD for use with hp-bioscfg driver
+ *
+ * Copyright (c) 2022 HP Development Company, L.P.
+ */
+
+#include "bioscfg.h"
+
+static const char * const spm_state_types[] = {
+ "not provisioned",
+ "provisioned",
+ "provisioning in progress",
+};
+
+static const char * const spm_mechanism_types[] = {
+ "not provisioned",
+ "signing-key",
+ "endorsement-key",
+};
+
+struct secureplatform_provisioning_data {
+ u8 state;
+ u8 version[2];
+ u8 reserved1;
+ u32 features;
+ u32 nonce;
+ u8 reserved2[28];
+ u8 sk_mod[MAX_KEY_MOD_SIZE];
+ u8 kek_mod[MAX_KEY_MOD_SIZE];
+};
+
+/**
+ * hp_calculate_security_buffer() - determines size of security buffer
+ * for authentication scheme
+ *
+ * @authentication: the authentication content
+ *
+ * Currently only supported type is Admin password
+ */
+size_t hp_calculate_security_buffer(const char *authentication)
+{
+ size_t size, authlen;
+
+ if (!authentication)
+ return sizeof(u16) * 2;
+
+ authlen = strlen(authentication);
+ if (!authlen)
+ return sizeof(u16) * 2;
+
+ size = sizeof(u16) + authlen * sizeof(u16);
+ if (!strstarts(authentication, BEAM_PREFIX))
+ size += strlen(UTF_PREFIX) * sizeof(u16);
+
+ return size;
+}
+
+/**
+ * hp_populate_security_buffer() - builds a security buffer for
+ * authentication scheme
+ *
+ * @authbuf: the security buffer
+ * @authentication: the authentication content
+ *
+ * Currently only supported type is PLAIN TEXT
+ */
+int hp_populate_security_buffer(u16 *authbuf, const char *authentication)
+{
+ u16 *auth = authbuf;
+ char *strprefix = NULL;
+ int ret = 0;
+
+ if (strstarts(authentication, BEAM_PREFIX)) {
+ /*
+ * BEAM_PREFIX is append to authbuf when a signature
+ * is provided and Sure Admin is enabled in BIOS
+ */
+ /* BEAM_PREFIX found, convert part to unicode */
+ auth = hp_ascii_to_utf16_unicode(auth, authentication);
+ if (!auth)
+ return -EINVAL;
+
+ } else {
+ /*
+ * UTF-16 prefix is append to the * authbuf when a BIOS
+ * admin password is configured in BIOS
+ */
+
+ /* append UTF_PREFIX to part and then convert it to unicode */
+ strprefix = kasprintf(GFP_KERNEL, "%s%s", UTF_PREFIX,
+ authentication);
+ if (!strprefix)
+ return -ENOMEM;
+
+ auth = hp_ascii_to_utf16_unicode(auth, strprefix);
+ kfree(strprefix);
+
+ if (!auth) {
+ ret = -EINVAL;
+ goto out_buffer;
+ }
+ }
+
+out_buffer:
+ return ret;
+}
+
+static ssize_t update_spm_state(void)
+{
+ struct secureplatform_provisioning_data data;
+ int ret;
+
+ ret = hp_wmi_perform_query(HPWMI_SECUREPLATFORM_GET_STATE,
+ HPWMI_SECUREPLATFORM, &data, 0,
+ sizeof(data));
+ if (ret < 0)
+ return ret;
+
+ bioscfg_drv.spm_data.mechanism = data.state;
+ if (bioscfg_drv.spm_data.mechanism)
+ bioscfg_drv.spm_data.is_enabled = 1;
+
+ return 0;
+}
+
+static ssize_t statusbin(struct kobject *kobj,
+ struct kobj_attribute *attr,
+ struct secureplatform_provisioning_data *buf)
+{
+ int ret = hp_wmi_perform_query(HPWMI_SECUREPLATFORM_GET_STATE,
+ HPWMI_SECUREPLATFORM, buf, 0,
+ sizeof(*buf));
+
+ if (ret < 0)
+ return ret;
+
+ return sizeof(struct secureplatform_provisioning_data);
+}
+
+/*
+ * status_show - Reads SPM status
+ */
+static ssize_t status_show(struct kobject *kobj, struct kobj_attribute
+ *attr, char *buf)
+{
+ int ret, i;
+ int len = 0;
+ struct secureplatform_provisioning_data data;
+
+ ret = statusbin(kobj, attr, &data);
+ if (ret < 0)
+ return ret;
+
+ /*
+ * 'status' is a read-only file that returns ASCII text in
+ * JSON format reporting the status information.
+ *
+ * "State": "not provisioned | provisioned | provisioning in progress ",
+ * "Version": " Major. Minor ",
+ * "Nonce": <16-bit unsigned number display in base 10>,
+ * "FeaturesInUse": <16-bit unsigned number display in base 10>,
+ * "EndorsementKeyMod": "<256 bytes in base64>",
+ * "SigningKeyMod": "<256 bytes in base64>"
+ */
+
+ len += sysfs_emit_at(buf, len, "{\n");
+ len += sysfs_emit_at(buf, len, "\t\"State\": \"%s\",\n",
+ spm_state_types[data.state]);
+ len += sysfs_emit_at(buf, len, "\t\"Version\": \"%d.%d\"",
+ data.version[0], data.version[1]);
+
+ /*
+ * state == 0 means secure platform management
+ * feature is not configured in BIOS.
+ */
+ if (data.state == 0) {
+ len += sysfs_emit_at(buf, len, "\n");
+ goto status_exit;
+ } else {
+ len += sysfs_emit_at(buf, len, ",\n");
+ }
+
+ len += sysfs_emit_at(buf, len, "\t\"Nonce\": %d,\n", data.nonce);
+ len += sysfs_emit_at(buf, len, "\t\"FeaturesInUse\": %d,\n", data.features);
+ len += sysfs_emit_at(buf, len, "\t\"EndorsementKeyMod\": \"");
+
+ for (i = 255; i >= 0; i--)
+ len += sysfs_emit_at(buf, len, " %u", data.kek_mod[i]);
+
+ len += sysfs_emit_at(buf, len, " \",\n");
+ len += sysfs_emit_at(buf, len, "\t\"SigningKeyMod\": \"");
+
+ for (i = 255; i >= 0; i--)
+ len += sysfs_emit_at(buf, len, " %u", data.sk_mod[i]);
+
+ /* Return buf contents */
+ len += sysfs_emit_at(buf, len, " \"\n");
+
+status_exit:
+ len += sysfs_emit_at(buf, len, "}\n");
+
+ return len;
+}
+
+static struct kobj_attribute password_spm_status = __ATTR_RO(status);
+
+ATTRIBUTE_SPM_N_PROPERTY_SHOW(is_enabled, spm);
+static struct kobj_attribute password_spm_is_key_enabled = __ATTR_RO(is_enabled);
+
+static ssize_t key_mechanism_show(struct kobject *kobj, struct kobj_attribute *attr,
+ char *buf)
+{
+ return sysfs_emit(buf, "%s\n",
+ spm_mechanism_types[bioscfg_drv.spm_data.mechanism]);
+}
+
+static struct kobj_attribute password_spm_key_mechanism = __ATTR_RO(key_mechanism);
+
+static ssize_t sk_store(struct kobject *kobj,
+ struct kobj_attribute *attr,
+ const char *buf, size_t count)
+{
+ int ret;
+ int length;
+
+ length = count;
+ if (buf[length - 1] == '\n')
+ length--;
+
+ /* allocate space and copy current signing key */
+ bioscfg_drv.spm_data.signing_key = kmalloc(length, GFP_KERNEL);
+ if (!bioscfg_drv.spm_data.signing_key)
+ return -ENOMEM;
+
+ strscpy(bioscfg_drv.spm_data.signing_key, buf, length);
+ bioscfg_drv.spm_data.signing_key[length] = '\0';
+
+ /* submit signing key payload */
+ ret = hp_wmi_perform_query(HPWMI_SECUREPLATFORM_SET_SK,
+ HPWMI_SECUREPLATFORM,
+ bioscfg_drv.spm_data.signing_key,
+ length, 0);
+
+ if (!ret) {
+ bioscfg_drv.spm_data.mechanism = SIGNING_KEY;
+ hp_set_reboot_and_signal_event();
+ }
+
+ kfree(bioscfg_drv.spm_data.signing_key);
+ bioscfg_drv.spm_data.signing_key = NULL;
+
+ return ret ? ret : count;
+}
+
+static struct kobj_attribute password_spm_signing_key = __ATTR_WO(sk);
+
+static ssize_t kek_store(struct kobject *kobj,
+ struct kobj_attribute *attr,
+ const char *buf, size_t count)
+{
+ int ret;
+ int length;
+
+ length = count;
+ if (buf[length - 1] == '\n')
+ length--;
+
+ /* allocate space and copy current signing key */
+ bioscfg_drv.spm_data.endorsement_key = kmalloc(length, GFP_KERNEL);
+ if (!bioscfg_drv.spm_data.endorsement_key) {
+ ret = -ENOMEM;
+ goto exit_kek;
+ }
+
+ memcpy(bioscfg_drv.spm_data.endorsement_key, buf, length);
+ bioscfg_drv.spm_data.endorsement_key[length] = '\0';
+
+ ret = hp_wmi_perform_query(HPWMI_SECUREPLATFORM_SET_KEK,
+ HPWMI_SECUREPLATFORM,
+ (void *)bioscfg_drv.spm_data.endorsement_key,
+ count, 0);
+
+ if (!ret) {
+ bioscfg_drv.spm_data.mechanism = ENDORSEMENT_KEY;
+ hp_set_reboot_and_signal_event();
+ }
+
+exit_kek:
+ kfree(bioscfg_drv.spm_data.endorsement_key);
+ bioscfg_drv.spm_data.endorsement_key = NULL;
+
+ return ret ? ret : count;
+}
+
+static struct kobj_attribute password_spm_endorsement_key = __ATTR_WO(kek);
+
+static ssize_t role_show(struct kobject *kobj, struct kobj_attribute *attr,
+ char *buf)
+{
+ return sysfs_emit(buf, "%s\n", BIOS_SPM);
+}
+
+static struct kobj_attribute password_spm_role = __ATTR_RO(role);
+
+static ssize_t auth_token_store(struct kobject *kobj,
+ struct kobj_attribute *attr,
+ const char *buf, size_t count)
+{
+ int ret = 0;
+ int length;
+
+ length = count;
+ if (buf[length - 1] == '\n')
+ length--;
+
+ /* allocate space and copy current auth token */
+ bioscfg_drv.spm_data.auth_token = kmalloc(count, GFP_KERNEL);
+ if (!bioscfg_drv.spm_data.auth_token) {
+ ret = -ENOMEM;
+ goto exit_token;
+ }
+
+ memcpy(bioscfg_drv.spm_data.auth_token, buf, count);
+ bioscfg_drv.spm_data.auth_token[length] = '\0';
+ return count;
+
+exit_token:
+ kfree(bioscfg_drv.spm_data.auth_token);
+ bioscfg_drv.spm_data.auth_token = NULL;
+
+ return ret;
+}
+
+static struct kobj_attribute password_spm_auth_token = __ATTR_WO(auth_token);
+
+static struct attribute *secure_platform_attrs[] = {
+ &password_spm_is_key_enabled.attr,
+ &password_spm_signing_key.attr,
+ &password_spm_endorsement_key.attr,
+ &password_spm_key_mechanism.attr,
+ &password_spm_status.attr,
+ &password_spm_role.attr,
+ &password_spm_auth_token.attr,
+ NULL,
+};
+
+static const struct attribute_group secure_platform_attr_group = {
+ .attrs = secure_platform_attrs,
+};
+
+void hp_exit_secure_platform_attributes(void)
+{
+ /* remove secure platform sysfs entry and free key data*/
+
+ kfree(bioscfg_drv.spm_data.endorsement_key);
+ bioscfg_drv.spm_data.endorsement_key = NULL;
+
+ kfree(bioscfg_drv.spm_data.signing_key);
+ bioscfg_drv.spm_data.signing_key = NULL;
+
+ kfree(bioscfg_drv.spm_data.auth_token);
+ bioscfg_drv.spm_data.auth_token = NULL;
+
+ if (bioscfg_drv.spm_data.attr_name_kobj)
+ sysfs_remove_group(bioscfg_drv.spm_data.attr_name_kobj,
+ &secure_platform_attr_group);
+}
+
+int hp_populate_secure_platform_data(struct kobject *attr_name_kobj)
+{
+ /* Populate data for Secure Platform Management */
+ bioscfg_drv.spm_data.attr_name_kobj = attr_name_kobj;
+
+ strscpy(bioscfg_drv.spm_data.attribute_name, SPM_STR,
+ sizeof(bioscfg_drv.spm_data.attribute_name));
+
+ bioscfg_drv.spm_data.is_enabled = 0;
+ bioscfg_drv.spm_data.mechanism = 0;
+ bioscfg_drv.pending_reboot = false;
+ update_spm_state();
+
+ bioscfg_drv.spm_data.endorsement_key = NULL;
+ bioscfg_drv.spm_data.signing_key = NULL;
+ bioscfg_drv.spm_data.auth_token = NULL;
+
+ return sysfs_create_group(attr_name_kobj, &secure_platform_attr_group);
+}
--
2.34.1


2023-05-17 16:00:19

by Jorge Lopez

[permalink] [raw]
Subject: [PATCH v14 04/13] hp-bioscfg: biosattr-interface

HP BIOS Configuration driver purpose is to provide a driver supporting
the latest sysfs class firmware attributes framework allowing the user
to change BIOS settings and security solutions on HP Inc.’s commercial
notebooks.

Many features of HP Commercial notebooks can be managed using Windows
Management Instrumentation (WMI). WMI is an implementation of Web-Based
Enterprise Management (WBEM) that provides a standards-based interface
for changing and monitoring system settings. HP BIOSCFG driver provides
a native Linux solution and the exposed features facilitates the
migration to Linux environments.

The Linux security features to be provided in hp-bioscfg driver enables
managing the BIOS settings and security solutions via sysfs, a virtual
filesystem that can be used by user-mode applications. The new
documentation cover HP-specific firmware sysfs attributes such Secure
Platform Management and Sure Start. Each section provides security
feature description and identifies sysfs directories and files exposed
by the driver.

Many HP Commercial notebooks include a feature called Secure Platform
Management (SPM), which replaces older password-based BIOS settings
management with public key cryptography. PC secure product management
begins when a target system is provisioned with cryptographic keys
that are used to ensure the integrity of communications between system
management utilities and the BIOS.

HP Commercial notebooks have several BIOS settings that control its
behaviour and capabilities, many of which are related to security.
To prevent unauthorized changes to these settings, the system can
be configured to use a cryptographic signature-based authorization
string that the BIOS will use to verify authorization to modify the
setting.

Linux Security components are under development and not published yet.
The only linux component is the driver (hp bioscfg) at this time.
Other published security components are under Windows.

Signed-off-by: Jorge Lopez <[email protected]>

---
Based on the latest platform-drivers-x86.git/for-next
---
.../x86/hp/hp-bioscfg/biosattr-interface.c | 317 ++++++++++++++++++
1 file changed, 317 insertions(+)
create mode 100644 drivers/platform/x86/hp/hp-bioscfg/biosattr-interface.c

diff --git a/drivers/platform/x86/hp/hp-bioscfg/biosattr-interface.c b/drivers/platform/x86/hp/hp-bioscfg/biosattr-interface.c
new file mode 100644
index 000000000000..1325491a8332
--- /dev/null
+++ b/drivers/platform/x86/hp/hp-bioscfg/biosattr-interface.c
@@ -0,0 +1,317 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Functions corresponding to methods under BIOS interface GUID
+ * for use with hp-bioscfg driver.
+ *
+ * Copyright (c) 2022 Hewlett-Packard Inc.
+ */
+
+#include <linux/wmi.h>
+#include "bioscfg.h"
+
+/*
+ * struct bios_args buffer is dynamically allocated. New WMI command types
+ * were introduced that exceeds 128-byte data size. Changes to handle
+ * the data size allocation scheme were kept in hp_wmi_perform_query function.
+ */
+struct bios_args {
+ u32 signature;
+ u32 command;
+ u32 commandtype;
+ u32 datasize;
+ u8 data[];
+};
+
+/**
+ * hp_set_attribute
+ *
+ * @a_name: The attribute name
+ * @a_value: The attribute value
+ *
+ * Sets an attribute to new value
+ *
+ * Returns zero on success
+ * -ENODEV if device is not found
+ * -EINVAL if the instance of 'Setup Admin' password is not found.
+ * -ENOMEM unable to allocate memory
+ */
+int hp_set_attribute(const char *a_name, const char *a_value)
+{
+ int security_area_size;
+ int a_name_size, a_value_size;
+ u16 *buffer = NULL;
+ u16 *start;
+ int buffer_size, instance, ret;
+ char *auth_token_choice;
+
+ mutex_lock(&bioscfg_drv.mutex);
+ if (!bioscfg_drv.bios_attr_wdev) {
+ ret = -ENODEV;
+ goto out_set_attribute;
+ }
+
+ instance = hp_get_password_instance_for_type(SETUP_PASSWD);
+ if (instance < 0) {
+ ret = -EINVAL;
+ goto out_set_attribute;
+ }
+
+ /* Select which auth token to use; password or [auth token] */
+ if (bioscfg_drv.spm_data.auth_token)
+ auth_token_choice = bioscfg_drv.spm_data.auth_token;
+ else
+ auth_token_choice = bioscfg_drv.password_data[instance].current_password;
+
+ a_name_size = hp_calculate_string_buffer(a_name);
+ a_value_size = hp_calculate_string_buffer(a_value);
+ security_area_size = hp_calculate_security_buffer(auth_token_choice);
+ buffer_size = a_name_size + a_value_size + security_area_size;
+
+ buffer = kmalloc(buffer_size + 1, GFP_KERNEL);
+ if (!buffer) {
+ ret = -ENOMEM;
+ goto out_set_attribute;
+ }
+
+ /* build variables to set */
+ start = buffer;
+ start = hp_ascii_to_utf16_unicode(start, a_name);
+ if (!start) {
+ ret = -EINVAL;
+ goto out_set_attribute;
+ }
+
+ start = hp_ascii_to_utf16_unicode(start, a_value);
+ if (!start) {
+ ret = -EINVAL;
+ goto out_set_attribute;
+ }
+
+ ret = hp_populate_security_buffer(start, auth_token_choice);
+ if (ret < 0)
+ goto out_set_attribute;
+
+ ret = hp_wmi_set_bios_setting(buffer, buffer_size);
+
+out_set_attribute:
+ kfree(buffer);
+ mutex_unlock(&bioscfg_drv.mutex);
+ return ret;
+}
+
+/**
+ * hp_wmi_perform_query
+ *
+ * @query: The commandtype (enum hp_wmi_commandtype)
+ * @command: The command (enum hp_wmi_command)
+ * @buffer: Buffer used as input and/or output
+ * @insize: Size of input buffer
+ * @outsize: Size of output buffer
+ *
+ * returns zero on success
+ * an HP WMI query specific error code (which is positive)
+ * -EINVAL if the query was not successful at all
+ * -EINVAL if the output buffer size exceeds buffersize
+ *
+ * Note: The buffersize must at least be the maximum of the input and output
+ * size. E.g. Battery info query is defined to have 1 byte input
+ * and 128 byte output. The caller would do:
+ * buffer = kzalloc(128, GFP_KERNEL);
+ * ret = hp_wmi_perform_query(HPWMI_BATTERY_QUERY, HPWMI_READ,
+ * buffer, 1, 128)
+ */
+int hp_wmi_perform_query(int query, enum hp_wmi_command command, void *buffer,
+ u32 insize, u32 outsize)
+{
+ struct acpi_buffer input, output = { ACPI_ALLOCATE_BUFFER, NULL };
+ struct bios_return *bios_return;
+ union acpi_object *obj = NULL;
+ struct bios_args *args = NULL;
+ u32 mid, actual_outsize, ret;
+ size_t bios_args_size;
+
+ mid = hp_encode_outsize_for_pvsz(outsize);
+ if (WARN_ON(mid < 0))
+ return mid;
+
+ bios_args_size = struct_size(args, data, insize);
+ args = kmalloc(bios_args_size, GFP_KERNEL);
+ if (!args)
+ return -ENOMEM;
+
+ input.length = bios_args_size;
+ input.pointer = args;
+
+ /* BIOS expects 'SECU' in hex as the signature value*/
+ args->signature = 0x55434553;
+ args->command = command;
+ args->commandtype = query;
+ args->datasize = insize;
+ memcpy(args->data, buffer, flex_array_size(args, data, insize));
+
+ ret = wmi_evaluate_method(HP_WMI_BIOS_GUID, 0, mid, &input, &output);
+ if (ret)
+ goto out_free;
+
+ obj = output.pointer;
+ if (!obj) {
+ ret = -EINVAL;
+ goto out_free;
+ }
+
+ if (obj->type != ACPI_TYPE_BUFFER ||
+ obj->buffer.length < sizeof(*bios_return)) {
+ pr_warn("query 0x%x returned wrong type or too small buffer\n", query);
+ ret = -EINVAL;
+ goto out_free;
+ }
+
+ bios_return = (struct bios_return *)obj->buffer.pointer;
+ ret = bios_return->return_code;
+ if (ret) {
+ if (ret != INVALID_CMD_VALUE && ret != INVALID_CMD_TYPE)
+ pr_warn("query 0x%x returned error 0x%x\n", query, ret);
+ goto out_free;
+ }
+
+ /* Ignore output data of zero size */
+ if (!outsize)
+ goto out_free;
+
+ actual_outsize = min_t(u32, outsize, obj->buffer.length - sizeof(*bios_return));
+ memcpy_and_pad(buffer, outsize, obj->buffer.pointer + sizeof(*bios_return),
+ actual_outsize, 0);
+
+out_free:
+ hp_wmi_error_and_message(ret);
+ kfree(obj);
+ kfree(args);
+ return ret;
+}
+
+static void *utf16_empty_string(u16 *p)
+{
+ *p++ = 2;
+ *p++ = 0x00;
+ return p;
+}
+
+/**
+ * hp_ascii_to_utf16_unicode - Convert ascii string to UTF-16 unicode
+ *
+ * BIOS supports UTF-16 characters that are 2 bytes long. No variable
+ * multi-byte language supported.
+ *
+ * @p: Unicode buffer address
+ * @str: string to convert to unicode
+ *
+ * Returns a void pointer to the buffer string
+ */
+void *hp_ascii_to_utf16_unicode(u16 *p, const u8 *str)
+{
+ int len = strlen(str);
+ int ret;
+
+ /*
+ * Add null character when reading an empty string
+ * "02 00 00 00"
+ */
+ if (len == 0)
+ return utf16_empty_string(p);
+
+ /* Move pointer len * 2 number of bytes */
+ *p++ = len * 2;
+ ret = utf8s_to_utf16s(str, strlen(str), UTF16_HOST_ENDIAN, p, len);
+ if (ret < 0) {
+ dev_err(bioscfg_drv.class_dev, "UTF16 conversion failed\n");
+ return NULL;
+ }
+
+ if (ret * sizeof(u16) > U16_MAX) {
+ dev_err(bioscfg_drv.class_dev, "Error string too long\n");
+ return NULL;
+ }
+
+ p += len;
+ return p;
+}
+
+/**
+ * hp_wmi_set_bios_setting - Set setting's value in BIOS
+ *
+ * @input_buffer: Input buffer address
+ * @input_size: Input buffer size
+ *
+ * Returns: Count of unicode characters written to BIOS if successful, otherwise
+ * -ENOMEM unable to allocate memory
+ * -EINVAL buffer not allocated or too small
+ */
+int hp_wmi_set_bios_setting(u16 *input_buffer, u32 input_size)
+{
+ union acpi_object *obj;
+ struct acpi_buffer input = {input_size, input_buffer};
+ struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
+ int ret;
+
+ ret = wmi_evaluate_method(HP_WMI_SET_BIOS_SETTING_GUID, 0, 1, &input, &output);
+
+ obj = output.pointer;
+ if (!obj)
+ return -EINVAL;
+
+ if (obj->type != ACPI_TYPE_INTEGER) {
+ ret = -EINVAL;
+ goto out_free;
+ }
+
+ ret = obj->integer.value;
+ if (ret) {
+ hp_wmi_error_and_message(ret);
+ goto out_free;
+ }
+
+out_free:
+ kfree(obj);
+ return ret;
+}
+
+static int hp_attr_set_interface_probe(struct wmi_device *wdev, const void *context)
+{
+ mutex_lock(&bioscfg_drv.mutex);
+ bioscfg_drv.bios_attr_wdev = wdev;
+ mutex_unlock(&bioscfg_drv.mutex);
+ return 0;
+}
+
+static void hp_attr_set_interface_remove(struct wmi_device *wdev)
+{
+ mutex_lock(&bioscfg_drv.mutex);
+ bioscfg_drv.bios_attr_wdev = NULL;
+ mutex_unlock(&bioscfg_drv.mutex);
+}
+
+static const struct wmi_device_id hp_attr_set_interface_id_table[] = {
+ { .guid_string = HP_WMI_BIOS_GUID},
+ { }
+};
+
+static struct wmi_driver hp_attr_set_interface_driver = {
+ .driver = {
+ .name = DRIVER_NAME,
+ },
+ .probe = hp_attr_set_interface_probe,
+ .remove = hp_attr_set_interface_remove,
+ .id_table = hp_attr_set_interface_id_table,
+};
+
+int hp_init_attr_set_interface(void)
+{
+ return wmi_driver_register(&hp_attr_set_interface_driver);
+}
+
+void hp_exit_attr_set_interface(void)
+{
+ wmi_driver_unregister(&hp_attr_set_interface_driver);
+}
+
+MODULE_DEVICE_TABLE(wmi, hp_attr_set_interface_id_table);
--
2.34.1


2023-05-17 16:00:21

by Jorge Lopez

[permalink] [raw]
Subject: [PATCH v14 10/13] hp-bioscfg: string-attributes

HP BIOS Configuration driver purpose is to provide a driver supporting
the latest sysfs class firmware attributes framework allowing the user
to change BIOS settings and security solutions on HP Inc.’s commercial
notebooks.

Many features of HP Commercial notebooks can be managed using Windows
Management Instrumentation (WMI). WMI is an implementation of Web-Based
Enterprise Management (WBEM) that provides a standards-based interface
for changing and monitoring system settings. HP BIOSCFG driver provides
a native Linux solution and the exposed features facilitates the
migration to Linux environments.

The Linux security features to be provided in hp-bioscfg driver enables
managing the BIOS settings and security solutions via sysfs, a virtual
filesystem that can be used by user-mode applications. The new
documentation cover HP-specific firmware sysfs attributes such Secure
Platform Management and Sure Start. Each section provides security
feature description and identifies sysfs directories and files exposed
by the driver.

Many HP Commercial notebooks include a feature called Secure Platform
Management (SPM), which replaces older password-based BIOS settings
management with public key cryptography. PC secure product management
begins when a target system is provisioned with cryptographic keys
that are used to ensure the integrity of communications between system
management utilities and the BIOS.

HP Commercial notebooks have several BIOS settings that control its
behaviour and capabilities, many of which are related to security.
To prevent unauthorized changes to these settings, the system can
be configured to use a cryptographic signature-based authorization
string that the BIOS will use to verify authorization to modify the
setting.

Linux Security components are under development and not published yet.
The only linux component is the driver (hp bioscfg) at this time.
Other published security components are under Windows.

Signed-off-by: Jorge Lopez <[email protected]>

---
Based on the latest platform-drivers-x86.git/for-next
---
.../x86/hp/hp-bioscfg/string-attributes.c | 404 ++++++++++++++++++
1 file changed, 404 insertions(+)
create mode 100644 drivers/platform/x86/hp/hp-bioscfg/string-attributes.c

diff --git a/drivers/platform/x86/hp/hp-bioscfg/string-attributes.c b/drivers/platform/x86/hp/hp-bioscfg/string-attributes.c
new file mode 100644
index 000000000000..39209171662b
--- /dev/null
+++ b/drivers/platform/x86/hp/hp-bioscfg/string-attributes.c
@@ -0,0 +1,404 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Functions corresponding to string type attributes under
+ * HP_WMI_BIOS_STRING_GUID for use with hp-bioscfg driver.
+ *
+ * Copyright (c) 2022 HP Development Company, L.P.
+ */
+
+#include "bioscfg.h"
+
+#define WMI_STRING_TYPE "HPBIOS_BIOSString"
+
+GET_INSTANCE_ID(string);
+
+static ssize_t current_value_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
+{
+ int instance_id = get_string_instance_id(kobj);
+
+ if (instance_id < 0)
+ return -EIO;
+
+ return sysfs_emit(buf, "%s\n",
+ bioscfg_drv.string_data[instance_id].current_value);
+}
+
+/**
+ * validate_string_input() -
+ * Validate input of current_value against min and max lengths
+ *
+ * @instance_id: The instance on which input is validated
+ * @buf: Input value
+ */
+static int validate_string_input(int instance_id, const char *buf)
+{
+ int in_len = strlen(buf);
+ struct string_data *string_data = &bioscfg_drv.string_data[instance_id];
+
+ /* BIOS treats it as a read only attribute */
+ if (string_data->common.is_readonly)
+ return -EIO;
+
+ if (in_len < string_data->min_length || in_len > string_data->max_length)
+ return -ERANGE;
+
+ return 0;
+}
+
+static void update_string_value(int instance_id, char *attr_value)
+{
+ struct string_data *string_data = &bioscfg_drv.string_data[instance_id];
+
+ /* Write settings to BIOS */
+ strscpy(string_data->current_value, attr_value, sizeof(string_data->current_value));
+}
+
+/*
+ * ATTRIBUTE_S_COMMON_PROPERTY_SHOW(display_name_language_code, string);
+ * static struct kobj_attribute string_display_langcode =
+ * __ATTR_RO(display_name_language_code);
+ */
+
+ATTRIBUTE_S_COMMON_PROPERTY_SHOW(display_name, string);
+static struct kobj_attribute string_display_name =
+ __ATTR_RO(display_name);
+
+ATTRIBUTE_PROPERTY_STORE(current_value, string);
+static struct kobj_attribute string_current_val =
+ __ATTR_RW_MODE(current_value, 0644);
+
+ATTRIBUTE_N_PROPERTY_SHOW(min_length, string);
+static struct kobj_attribute string_min_length =
+ __ATTR_RO(min_length);
+
+ATTRIBUTE_N_PROPERTY_SHOW(max_length, string);
+static struct kobj_attribute string_max_length =
+ __ATTR_RO(max_length);
+
+static ssize_t type_show(struct kobject *kobj, struct kobj_attribute *attr,
+ char *buf)
+{
+ return sysfs_emit(buf, "string\n");
+}
+
+static struct kobj_attribute string_type =
+ __ATTR_RO(type);
+
+static struct kobj_attribute common_display_langcode =
+ __ATTR_RO(display_name_language_code);
+
+static struct attribute *string_attrs[] = {
+ &common_display_langcode.attr,
+ &string_display_name.attr,
+ &string_current_val.attr,
+ &string_min_length.attr,
+ &string_max_length.attr,
+ &string_type.attr,
+ NULL
+};
+
+static const struct attribute_group string_attr_group = {
+ .attrs = string_attrs,
+};
+
+int hp_alloc_string_data(void)
+{
+ bioscfg_drv.string_instances_count = hp_get_instance_count(HP_WMI_BIOS_STRING_GUID);
+ bioscfg_drv.string_data = kcalloc(bioscfg_drv.string_instances_count,
+ sizeof(*bioscfg_drv.string_data), GFP_KERNEL);
+ if (!bioscfg_drv.string_data) {
+ bioscfg_drv.string_instances_count = 0;
+ return -ENOMEM;
+ }
+ return 0;
+}
+
+/* Expected Values types associated with each element */
+static const acpi_object_type expected_string_types[] = {
+ [NAME] = ACPI_TYPE_STRING,
+ [VALUE] = ACPI_TYPE_STRING,
+ [PATH] = ACPI_TYPE_STRING,
+ [IS_READONLY] = ACPI_TYPE_INTEGER,
+ [DISPLAY_IN_UI] = ACPI_TYPE_INTEGER,
+ [REQUIRES_PHYSICAL_PRESENCE] = ACPI_TYPE_INTEGER,
+ [SEQUENCE] = ACPI_TYPE_INTEGER,
+ [PREREQUISITES_SIZE] = ACPI_TYPE_INTEGER,
+ [PREREQUISITES] = ACPI_TYPE_STRING,
+ [SECURITY_LEVEL] = ACPI_TYPE_INTEGER,
+ [STR_MIN_LENGTH] = ACPI_TYPE_INTEGER,
+ [STR_MAX_LENGTH] = ACPI_TYPE_INTEGER,
+};
+
+static int hp_populate_string_elements_from_package(union acpi_object *string_obj,
+ int string_obj_count,
+ int instance_id)
+{
+ char *str_value = NULL;
+ int value_len;
+ int ret = 0;
+ u32 int_value;
+ int elem;
+ int reqs;
+ int eloc;
+ int size;
+ struct string_data *string_data = &bioscfg_drv.string_data[instance_id];
+
+ if (!string_obj)
+ return -EINVAL;
+
+ for (elem = 1, eloc = 1; elem < string_obj_count; elem++, eloc++) {
+ /* ONLY look at the first STRING_ELEM_CNT elements */
+ if (eloc == STR_ELEM_CNT)
+ goto exit_string_package;
+
+ switch (string_obj[elem].type) {
+ case ACPI_TYPE_STRING:
+ if (elem != PREREQUISITES) {
+ ret = hp_convert_hexstr_to_str(string_obj[elem].string.pointer,
+ string_obj[elem].string.length,
+ &str_value, &value_len);
+
+ if (ret)
+ continue;
+ }
+ break;
+ case ACPI_TYPE_INTEGER:
+ int_value = (u32)string_obj[elem].integer.value;
+ break;
+ default:
+ pr_warn("Unsupported object type [%d]\n", string_obj[elem].type);
+ continue;
+ }
+
+ /* Check that both expected and read object type match */
+ if (expected_string_types[eloc] != string_obj[elem].type) {
+ pr_err("Error expected type %d for elem %d, but got type %d instead\n",
+ expected_string_types[eloc], elem, string_obj[elem].type);
+ return -EIO;
+ }
+
+ /* Assign appropriate element value to corresponding field*/
+ switch (eloc) {
+ case VALUE:
+ strscpy(string_data->current_value,
+ str_value, sizeof(string_data->current_value));
+ break;
+ case PATH:
+ strscpy(string_data->common.path, str_value,
+ sizeof(string_data->common.path));
+ break;
+ case IS_READONLY:
+ string_data->common.is_readonly = int_value;
+ break;
+ case DISPLAY_IN_UI:
+ string_data->common.display_in_ui = int_value;
+ break;
+ case REQUIRES_PHYSICAL_PRESENCE:
+ string_data->common.requires_physical_presence = int_value;
+ break;
+ case SEQUENCE:
+ string_data->common.sequence = int_value;
+ break;
+ case PREREQUISITES_SIZE:
+ string_data->common.prerequisites_size = int_value;
+
+ if (string_data->common.prerequisites_size > MAX_PREREQUISITES_SIZE)
+ pr_warn("Prerequisites size value exceeded the maximum number of elements supported or data may be malformed\n");
+ /*
+ * This HACK is needed to keep the expected
+ * element list pointing to the right obj[elem].type
+ * when the size is zero. PREREQUISITES
+ * object is omitted by BIOS when the size is
+ * zero.
+ */
+ if (string_data->common.prerequisites_size == 0)
+ eloc++;
+ break;
+ case PREREQUISITES:
+ size = min_t(u32, string_data->common.prerequisites_size,
+ MAX_PREREQUISITES_SIZE);
+
+ for (reqs = 0; reqs < size; reqs++) {
+ if (elem >= string_obj_count) {
+ pr_err("Error elem-objects package is too small\n");
+ return -EINVAL;
+ }
+
+ ret = hp_convert_hexstr_to_str(string_obj[elem + reqs].string.pointer,
+ string_obj[elem + reqs].string.length,
+ &str_value, &value_len);
+
+ if (ret)
+ continue;
+
+ strscpy(string_data->common.prerequisites[reqs],
+ str_value,
+ sizeof(string_data->common.prerequisites[reqs]));
+ kfree(str_value);
+ }
+ break;
+
+ case SECURITY_LEVEL:
+ string_data->common.security_level = int_value;
+ break;
+ case STR_MIN_LENGTH:
+ string_data->min_length = int_value;
+ break;
+ case STR_MAX_LENGTH:
+ string_data->max_length = int_value;
+ break;
+ default:
+ pr_warn("Invalid element: %d found in String attribute or data may be malformed\n", elem);
+ break;
+ }
+
+ kfree(str_value);
+ }
+
+exit_string_package:
+ kfree(str_value);
+ return 0;
+}
+
+/**
+ * hp_populate_string_package_data() -
+ * Populate all properties of an instance under string attribute
+ *
+ * @string_obj: ACPI object with string data
+ * @instance_id: The instance to enumerate
+ * @attr_name_kobj: The parent kernel object
+ */
+int hp_populate_string_package_data(union acpi_object *string_obj,
+ int instance_id,
+ struct kobject *attr_name_kobj)
+{
+ struct string_data *string_data = &bioscfg_drv.string_data[instance_id];
+
+ string_data->attr_name_kobj = attr_name_kobj;
+
+ hp_populate_string_elements_from_package(string_obj,
+ string_obj->package.count,
+ instance_id);
+
+ hp_update_attribute_permissions(string_data->common.is_readonly,
+ &string_current_val);
+ hp_friendly_user_name_update(string_data->common.path,
+ attr_name_kobj->name,
+ string_data->common.display_name,
+ sizeof(string_data->common.display_name));
+ return sysfs_create_group(attr_name_kobj, &string_attr_group);
+}
+
+static int hp_populate_string_elements_from_buffer(u8 *buffer_ptr, u32 *buffer_size,
+ int instance_id)
+{
+ int reqs;
+ struct string_data *string_data = &bioscfg_drv.string_data[instance_id];
+
+ // VALUE:
+ hp_get_string_from_buffer(&buffer_ptr, buffer_size, string_data->current_value,
+ sizeof(string_data->current_value));
+
+ // PATH:
+ hp_get_string_from_buffer(&buffer_ptr, buffer_size, string_data->common.path,
+ sizeof(string_data->common.path));
+
+ // IS_READONLY:
+ hp_get_integer_from_buffer(&buffer_ptr, buffer_size,
+ &string_data->common.is_readonly);
+
+ //DISPLAY_IN_UI:
+ hp_get_integer_from_buffer(&buffer_ptr, buffer_size,
+ &string_data->common.display_in_ui);
+
+ // REQUIRES_PHYSICAL_PRESENCE:
+ hp_get_integer_from_buffer(&buffer_ptr, buffer_size,
+ &string_data->common.requires_physical_presence);
+
+ // SEQUENCE:
+ hp_get_integer_from_buffer(&buffer_ptr, buffer_size,
+ &string_data->common.sequence);
+
+ // PREREQUISITES_SIZE:
+ hp_get_integer_from_buffer(&buffer_ptr, buffer_size,
+ &string_data->common.prerequisites_size);
+
+ if (string_data->common.prerequisites_size > MAX_PREREQUISITES_SIZE) {
+ /* Report a message and limit prerequisite size to maximum value */
+ pr_warn("String Prerequisites size value exceeded the maximum number of elements supported or data may be malformed\n");
+ string_data->common.prerequisites_size = MAX_PREREQUISITES_SIZE;
+ }
+
+ // PREREQUISITES:
+ for (reqs = 0; reqs < string_data->common.prerequisites_size; reqs++)
+ hp_get_string_from_buffer(&buffer_ptr, buffer_size,
+ string_data->common.prerequisites[reqs],
+ sizeof(string_data->common.prerequisites[reqs]));
+
+ // SECURITY_LEVEL:
+ hp_get_integer_from_buffer(&buffer_ptr, buffer_size,
+ &string_data->common.security_level);
+
+ // STR_MIN_LENGTH:
+ hp_get_integer_from_buffer(&buffer_ptr, buffer_size,
+ &string_data->min_length);
+
+ // STR_MAX_LENGTH:
+ hp_get_integer_from_buffer(&buffer_ptr, buffer_size,
+ &string_data->max_length);
+
+ return 0;
+}
+
+/**
+ * hp_populate_string_buffer_data() -
+ * Populate all properties of an instance under string attribute
+ *
+ * @buffer_ptr: Buffer pointer
+ * @buffer_size: Buffer size
+ * @instance_id: The instance to enumerate
+ * @attr_name_kobj: The parent kernel object
+ */
+int hp_populate_string_buffer_data(u8 *buffer_ptr, u32 *buffer_size,
+ int instance_id,
+ struct kobject *attr_name_kobj)
+{
+ struct string_data *string_data = &bioscfg_drv.string_data[instance_id];
+
+ string_data->attr_name_kobj = attr_name_kobj;
+
+ hp_populate_string_elements_from_buffer(buffer_ptr, buffer_size,
+ instance_id);
+
+ hp_update_attribute_permissions(string_data->common.is_readonly,
+ &string_current_val);
+ hp_friendly_user_name_update(string_data->common.path,
+ attr_name_kobj->name,
+ string_data->common.display_name,
+ sizeof(string_data->common.display_name));
+
+ return sysfs_create_group(attr_name_kobj, &string_attr_group);
+}
+
+/**
+ * hp_exit_string_attributes() - Clear all attribute data
+ *
+ * Clears all data allocated for this group of attributes
+ */
+void hp_exit_string_attributes(void)
+{
+ int instance_id;
+
+ for (instance_id = 0; instance_id < bioscfg_drv.string_instances_count;
+ instance_id++) {
+ struct kobject *attr_name_kobj =
+ bioscfg_drv.string_data[instance_id].attr_name_kobj;
+
+ if (attr_name_kobj)
+ sysfs_remove_group(attr_name_kobj, &string_attr_group);
+ }
+ bioscfg_drv.string_instances_count = 0;
+
+ kfree(bioscfg_drv.string_data);
+ bioscfg_drv.string_data = NULL;
+}
--
2.34.1


2023-05-17 16:00:24

by Jorge Lopez

[permalink] [raw]
Subject: [PATCH v14 02/13] hp-bioscfg: bioscfg-h

HP BIOS Configuration driver purpose is to provide a driver supporting
the latest sysfs class firmware attributes framework allowing the user
to change BIOS settings and security solutions on HP Inc.’s commercial
notebooks.

Many features of HP Commercial notebooks can be managed using Windows
Management Instrumentation (WMI). WMI is an implementation of Web-Based
Enterprise Management (WBEM) that provides a standards-based interface
for changing and monitoring system settings. HP BIOSCFG driver provides
a native Linux solution and the exposed features facilitates the
migration to Linux environments.

The Linux security features to be provided in hp-bioscfg driver enables
managing the BIOS settings and security solutions via sysfs, a virtual
filesystem that can be used by user-mode applications. The new
documentation cover HP-specific firmware sysfs attributes such Secure
Platform Management and Sure Start. Each section provides security
feature description and identifies sysfs directories and files exposed
by the driver.

Many HP Commercial notebooks include a feature called Secure Platform
Management (SPM), which replaces older password-based BIOS settings
management with public key cryptography. PC secure product management
begins when a target system is provisioned with cryptographic keys
that are used to ensure the integrity of communications between system
management utilities and the BIOS.

HP Commercial notebooks have several BIOS settings that control its
behaviour and capabilities, many of which are related to security.
To prevent unauthorized changes to these settings, the system can
be configured to use a cryptographic signature-based authorization
string that the BIOS will use to verify authorization to modify the
setting.

Linux Security components are under development and not published yet.
The only linux component is the driver (hp bioscfg) at this time.
Other published security components are under Windows.

Signed-off-by: Jorge Lopez <[email protected]>

---
Based on the latest platform-drivers-x86.git/for-next
---
drivers/platform/x86/hp/hp-bioscfg/bioscfg.h | 486 +++++++++++++++++++
1 file changed, 486 insertions(+)
create mode 100644 drivers/platform/x86/hp/hp-bioscfg/bioscfg.h

diff --git a/drivers/platform/x86/hp/hp-bioscfg/bioscfg.h b/drivers/platform/x86/hp/hp-bioscfg/bioscfg.h
new file mode 100644
index 000000000000..3a3b24f766d2
--- /dev/null
+++ b/drivers/platform/x86/hp/hp-bioscfg/bioscfg.h
@@ -0,0 +1,486 @@
+/* SPDX-License-Identifier: GPL-2.0
+ *
+ * Definitions for kernel modules using hp_bioscfg driver
+ *
+ * Copyright (c) 2022 HP Development Company, L.P.
+ */
+
+#ifndef _HP_BIOSCFG_H_
+#define _HP_BIOSCFG_H_
+
+#include <linux/wmi.h>
+#include <linux/types.h>
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/capability.h>
+#include <linux/nls.h>
+
+#define DRIVER_NAME "hp-bioscfg"
+
+#define MAX_BUFF_SIZE 512
+#define MAX_KEY_MOD_SIZE 256
+#define MAX_PASSWD_SIZE 64
+#define MAX_PREREQUISITES_SIZE 20
+#define MAX_REQ_ELEM_SIZE 128
+#define MAX_VALUES_SIZE 16
+#define MAX_ENCODINGS_SIZE 16
+#define MAX_ELEMENTS_SIZE 16
+
+#define SPM_STR_DESC "Secure Platform Management"
+#define SPM_STR "SPM"
+#define SURE_START_DESC "Sure Start"
+#define SURE_START_STR "Sure_Start"
+#define SETUP_PASSWD "Setup Password"
+#define POWER_ON_PASSWD "Power-On Password"
+
+#define LANG_CODE_STR "en_US.UTF-8"
+#define SCHEDULE_POWER_ON "Scheduled Power-On"
+
+#define COMMA_SEP ","
+#define SEMICOLON_SEP ";"
+
+/* Sure Admin Functions */
+
+#define UTF_PREFIX "<utf-16/>"
+#define BEAM_PREFIX "<BEAM/>"
+
+enum mechanism_values {
+ PASSWORD = 0x00,
+ SIGNING_KEY = 0x01,
+ ENDORSEMENT_KEY = 0x02,
+};
+
+#define BIOS_ADMIN "bios-admin"
+#define POWER_ON "power-on"
+#define BIOS_SPM "enhanced-bios-auth"
+
+#define PASSWD_MECHANISM_TYPES "password"
+
+#define HP_WMI_BIOS_GUID "5FB7F034-2C63-45e9-BE91-3D44E2C707E4"
+
+#define HP_WMI_BIOS_STRING_GUID "988D08E3-68F4-4c35-AF3E-6A1B8106F83C"
+#define HP_WMI_BIOS_INTEGER_GUID "8232DE3D-663D-4327-A8F4-E293ADB9BF05"
+#define HP_WMI_BIOS_ENUMERATION_GUID "2D114B49-2DFB-4130-B8FE-4A3C09E75133"
+#define HP_WMI_BIOS_ORDERED_LIST_GUID "14EA9746-CE1F-4098-A0E0-7045CB4DA745"
+#define HP_WMI_BIOS_PASSWORD_GUID "322F2028-0F84-4901-988E-015176049E2D"
+#define HP_WMI_SET_BIOS_SETTING_GUID "1F4C91EB-DC5C-460b-951D-C7CB9B4B8D5E"
+
+enum hp_wmi_spm_commandtype {
+ HPWMI_SECUREPLATFORM_GET_STATE = 0x10,
+ HPWMI_SECUREPLATFORM_SET_KEK = 0x11,
+ HPWMI_SECUREPLATFORM_SET_SK = 0x12,
+};
+
+enum hp_wmi_surestart_commandtype {
+ HPWMI_SURESTART_GET_LOG_COUNT = 0x01,
+ HPWMI_SURESTART_GET_LOG = 0x02,
+};
+
+enum hp_wmi_command {
+ HPWMI_READ = 0x01,
+ HPWMI_WRITE = 0x02,
+ HPWMI_ODM = 0x03,
+ HPWMI_SURESTART = 0x20006,
+ HPWMI_GM = 0x20008,
+ HPWMI_SECUREPLATFORM = 0x20010,
+};
+
+struct bios_return {
+ u32 sigpass;
+ u32 return_code;
+};
+
+enum wmi_error_values {
+ SUCCESS = 0x00,
+ CMD_FAILED = 0x01,
+ INVALID_SIGN = 0x02,
+ INVALID_CMD_VALUE = 0x03,
+ INVALID_CMD_TYPE = 0x04,
+ INVALID_DATA_SIZE = 0x05,
+ INVALID_CMD_PARAM = 0x06,
+ ENCRYP_CMD_REQUIRED = 0x07,
+ NO_SECURE_SESSION = 0x08,
+ SECURE_SESSION_FOUND = 0x09,
+ SECURE_SESSION_FAILED = 0x0A,
+ AUTH_FAILED = 0x0B,
+ INVALID_BIOS_AUTH = 0x0E,
+ NONCE_DID_NOT_MATCH = 0x18,
+ GENERIC_ERROR = 0x1C,
+ BIOS_ADMIN_POLICY_NOT_MET = 0x28,
+ BIOS_ADMIN_NOT_SET = 0x38,
+ P21_NO_PROVISIONED = 0x1000,
+ P21_PROVISION_IN_PROGRESS = 0x1001,
+ P21_IN_USE = 0x1002,
+ HEP_NOT_ACTIVE = 0x1004,
+ HEP_ALREADY_SET = 0x1006,
+ HEP_CHECK_STATE = 0x1007,
+};
+
+struct common_data {
+ u8 display_name[MAX_BUFF_SIZE];
+ u8 path[MAX_BUFF_SIZE];
+ u32 is_readonly;
+ u32 display_in_ui;
+ u32 requires_physical_presence;
+ u32 sequence;
+ u32 prerequisites_size;
+ u8 prerequisites[MAX_PREREQUISITES_SIZE][MAX_BUFF_SIZE];
+ u32 security_level;
+};
+
+struct string_data {
+ struct common_data common;
+ struct kobject *attr_name_kobj;
+ u8 current_value[MAX_BUFF_SIZE];
+ u8 new_value[MAX_BUFF_SIZE];
+ u32 min_length;
+ u32 max_length;
+};
+
+struct integer_data {
+ struct common_data common;
+ struct kobject *attr_name_kobj;
+ u32 current_value;
+ u32 new_value;
+ u32 lower_bound;
+ u32 upper_bound;
+ u32 scalar_increment;
+};
+
+struct enumeration_data {
+ struct common_data common;
+ struct kobject *attr_name_kobj;
+ u8 current_value[MAX_BUFF_SIZE];
+ u8 new_value[MAX_BUFF_SIZE];
+ u32 possible_values_size;
+ u8 possible_values[MAX_VALUES_SIZE][MAX_BUFF_SIZE];
+};
+
+struct ordered_list_data {
+ struct common_data common;
+ struct kobject *attr_name_kobj;
+ u8 current_value[MAX_BUFF_SIZE];
+ u8 new_value[MAX_BUFF_SIZE];
+ u32 elements_size;
+ u8 elements[MAX_ELEMENTS_SIZE][MAX_BUFF_SIZE];
+};
+
+struct password_data {
+ struct common_data common;
+ struct kobject *attr_name_kobj;
+ u8 current_password[MAX_PASSWD_SIZE];
+ u8 new_password[MAX_PASSWD_SIZE];
+ u32 min_password_length;
+ u32 max_password_length;
+ u32 encodings_size;
+ u8 encodings[MAX_ENCODINGS_SIZE][MAX_BUFF_SIZE];
+ bool is_enabled;
+
+ /*
+ * 'role' identifies the type of authentication.
+ * Two known types are bios-admin and power-on.
+ * 'bios-admin' represents BIOS administrator password
+ * 'power-on' represents a password required to use the system
+ */
+ u32 role;
+
+ /*
+ * 'mechanism' represents the means of authentication.
+ * Only supported type currently is "password"
+ */
+ u32 mechanism;
+};
+
+struct secure_platform_data {
+ struct kobject *attr_name_kobj;
+ u8 attribute_name[MAX_BUFF_SIZE];
+ u8 *endorsement_key;
+ u8 *signing_key;
+ u8 *auth_token;
+ bool is_enabled;
+ u32 mechanism;
+};
+
+struct bioscfg_priv {
+ struct wmi_device *bios_attr_wdev;
+ struct kset *authentication_dir_kset;
+ struct kset *main_dir_kset;
+ struct device *class_dev;
+ struct string_data *string_data;
+ u32 string_instances_count;
+ struct integer_data *integer_data;
+ u32 integer_instances_count;
+ struct enumeration_data *enumeration_data;
+ u32 enumeration_instances_count;
+ struct ordered_list_data *ordered_list_data;
+ u32 ordered_list_instances_count;
+ struct password_data *password_data;
+ u32 password_instances_count;
+
+ struct kobject *sure_start_attr_kobj;
+ struct secure_platform_data spm_data;
+ u8 display_name_language_code[MAX_BUFF_SIZE];
+ bool pending_reboot;
+ struct mutex mutex;
+};
+
+/* global structure used by multiple WMI interfaces */
+extern struct bioscfg_priv bioscfg_drv;
+
+enum hp_wmi_data_type {
+ HPWMI_STRING_TYPE,
+ HPWMI_INTEGER_TYPE,
+ HPWMI_ENUMERATION_TYPE,
+ HPWMI_ORDERED_LIST_TYPE,
+ HPWMI_PASSWORD_TYPE,
+ HPWMI_SECURE_PLATFORM_TYPE,
+ HPWMI_SURE_START_TYPE,
+};
+
+enum hp_wmi_data_elements {
+ /* Common elements */
+ NAME = 0,
+ VALUE = 1,
+ PATH = 2,
+ IS_READONLY = 3,
+ DISPLAY_IN_UI = 4,
+ REQUIRES_PHYSICAL_PRESENCE = 5,
+ SEQUENCE = 6,
+ PREREQUISITES_SIZE = 7,
+ PREREQUISITES = 8,
+ SECURITY_LEVEL = 9,
+
+ /* String elements */
+ STR_MIN_LENGTH = 10,
+ STR_MAX_LENGTH = 11,
+ STR_ELEM_CNT = 12,
+
+ /* Integer elements */
+ INT_LOWER_BOUND = 10,
+ INT_UPPER_BOUND = 11,
+ INT_SCALAR_INCREMENT = 12,
+ INT_ELEM_CNT = 13,
+
+ /* Enumeration elements */
+ ENUM_CURRENT_VALUE = 10,
+ ENUM_SIZE = 11,
+ ENUM_POSSIBLE_VALUES = 12,
+ ENUM_ELEM_CNT = 13,
+
+ /* Ordered list elements */
+ ORD_LIST_SIZE = 10,
+ ORD_LIST_ELEMENTS = 11,
+ ORD_ELEM_CNT = 12,
+
+ /* Password elements */
+ PSWD_MIN_LENGTH = 10,
+ PSWD_MAX_LENGTH = 11,
+ PSWD_SIZE = 12,
+ PSWD_ENCODINGS = 13,
+ PSWD_IS_SET = 14,
+ PSWD_ELEM_CNT = 15,
+};
+
+#define GET_INSTANCE_ID(type) \
+ static int get_##type##_instance_id(struct kobject *kobj) \
+ { \
+ int i; \
+ \
+ for (i = 0; i <= bioscfg_drv.type##_instances_count; i++) { \
+ if (!strcmp(kobj->name, bioscfg_drv.type##_data[i].attr_name_kobj->name)) \
+ return i; \
+ } \
+ return -EIO; \
+ }
+
+#define ATTRIBUTE_S_PROPERTY_SHOW(name, type) \
+ static ssize_t name##_show(struct kobject *kobj, struct kobj_attribute *attr, \
+ char *buf) \
+ { \
+ int i = get_##type##_instance_id(kobj); \
+ if (i >= 0) \
+ return sysfs_emit(buf, "%s\n", bioscfg_drv.type##_data[i].name); \
+ return -EIO; \
+ }
+
+#define ATTRIBUTE_N_PROPERTY_SHOW(name, type) \
+ static ssize_t name##_show(struct kobject *kobj, struct kobj_attribute *attr, \
+ char *buf) \
+ { \
+ int i = get_##type##_instance_id(kobj); \
+ if (i >= 0) \
+ return sysfs_emit(buf, "%d\n", bioscfg_drv.type##_data[i].name); \
+ return -EIO; \
+ }
+
+#define ATTRIBUTE_PROPERTY_STORE(curr_val, type) \
+ static ssize_t curr_val##_store(struct kobject *kobj, \
+ struct kobj_attribute *attr, \
+ const char *buf, size_t count) \
+ { \
+ char *attr_value = NULL; \
+ int i; \
+ int ret = -EIO; \
+ \
+ attr_value = kstrdup(buf, GFP_KERNEL); \
+ if (!attr_value) \
+ return -ENOMEM; \
+ \
+ ret = hp_enforce_single_line_input(attr_value, count); \
+ if (!ret) { \
+ i = get_##type##_instance_id(kobj); \
+ if (i >= 0) \
+ ret = validate_##type##_input(i, attr_value); \
+ } \
+ if (!ret) \
+ ret = hp_set_attribute(kobj->name, attr_value); \
+ if (!ret) { \
+ update_##type##_value(i, attr_value); \
+ if (bioscfg_drv.type##_data[i].common.requires_physical_presence) \
+ hp_set_reboot_and_signal_event(); \
+ } \
+ hp_clear_all_credentials(); \
+ kfree(attr_value); \
+ \
+ return ret ? ret : count; \
+ }
+
+#define ATTRIBUTE_SPM_N_PROPERTY_SHOW(name, type) \
+ static ssize_t name##_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf) \
+ { \
+ return sysfs_emit(buf, "%d\n", bioscfg_drv.type##_data.name); \
+ }
+
+#define ATTRIBUTE_SPM_S_PROPERTY_SHOW(name, type) \
+ static ssize_t name##_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf) \
+ { \
+ return sysfs_emit(buf, "%s\n", bioscfg_drv.type##_data.name); \
+ }
+
+#define ATTRIBUTE_VALUES_PROPERTY_SHOW(name, type, sep) \
+ static ssize_t name##_show(struct kobject *kobj, \
+ struct kobj_attribute *attr, char *buf) \
+ { \
+ int i; \
+ int len = 0; \
+ int instance_id = get_##type##_instance_id(kobj); \
+ \
+ if (instance_id < 0) \
+ return 0; \
+ \
+ for (i = 0; i < bioscfg_drv.type##_data[instance_id].name##_size; i++) { \
+ if (i) \
+ len += sysfs_emit_at(buf, len, "%s", sep); \
+ \
+ len += sysfs_emit_at(buf, len, "%s", \
+ bioscfg_drv.type##_data[instance_id].name[i]); \
+ } \
+ len += sysfs_emit_at(buf, len, "\n"); \
+ return len; \
+ }
+
+#define ATTRIBUTE_S_COMMON_PROPERTY_SHOW(name, type) \
+ static ssize_t name##_show(struct kobject *kobj, struct kobj_attribute *attr, \
+ char *buf) \
+ { \
+ int i = get_##type##_instance_id(kobj); \
+ if (i >= 0) \
+ return sysfs_emit(buf, "%s\n", bioscfg_drv.type##_data[i].common.name); \
+ return -EIO; \
+ }
+
+/* Prototypes */
+
+/* String attributes */
+int hp_populate_string_buffer_data(u8 *buffer_ptr, u32 *buffer_size,
+ int instance_id,
+ struct kobject *attr_name_kobj);
+int hp_alloc_string_data(void);
+void hp_exit_string_attributes(void);
+int hp_populate_string_package_data(union acpi_object *str_obj,
+ int instance_id,
+ struct kobject *attr_name_kobj);
+
+/* Integer attributes */
+int hp_populate_integer_buffer_data(u8 *buffer_ptr, u32 *buffer_size,
+ int instance_id,
+ struct kobject *attr_name_kobj);
+int hp_alloc_integer_data(void);
+void hp_exit_integer_attributes(void);
+int hp_populate_integer_package_data(union acpi_object *integer_obj,
+ int instance_id,
+ struct kobject *attr_name_kobj);
+
+/* Enumeration attributes */
+int hp_populate_enumeration_buffer_data(u8 *buffer_ptr, u32 *buffer_size,
+ int instance_id,
+ struct kobject *attr_name_kobj);
+int hp_alloc_enumeration_data(void);
+void hp_exit_enumeration_attributes(void);
+int hp_populate_enumeration_package_data(union acpi_object *enum_obj,
+ int instance_id,
+ struct kobject *attr_name_kobj);
+
+/* Ordered list */
+int hp_populate_ordered_list_buffer_data(u8 *buffer_ptr,
+ u32 *buffer_size,
+ int instance_id,
+ struct kobject *attr_name_kobj);
+int hp_alloc_ordered_list_data(void);
+void hp_exit_ordered_list_attributes(void);
+int hp_populate_ordered_list_package_data(union acpi_object *order_obj,
+ int instance_id,
+ struct kobject *attr_name_kobj);
+
+/* Password authentication attributes */
+int hp_populate_password_buffer_data(u8 *buffer_ptr, u32 *buffer_size,
+ int instance_id,
+ struct kobject *attr_name_kobj);
+int hp_populate_password_package_data(union acpi_object *password_obj,
+ int instance_id,
+ struct kobject *attr_name_kobj);
+int hp_alloc_password_data(void);
+int hp_get_password_instance_for_type(const char *name);
+int hp_clear_all_credentials(void);
+int hp_set_attribute(const char *a_name, const char *a_value);
+
+/* SPM attributes */
+void hp_exit_password_attributes(void);
+void hp_exit_secure_platform_attributes(void);
+int hp_populate_secure_platform_data(struct kobject *attr_name_kobj);
+int hp_populate_security_buffer(u16 *buffer, const char *authentication);
+
+/* Bios Attributes interface */
+int hp_wmi_set_bios_setting(u16 *input_buffer, u32 input_size);
+int hp_wmi_perform_query(int query, enum hp_wmi_command command,
+ void *buffer, u32 insize, u32 outsize);
+
+/* Sure Start attributes */
+void hp_exit_sure_start_attributes(void);
+int hp_populate_sure_start_data(struct kobject *attr_name_kobj);
+
+/* Bioscfg */
+
+void hp_exit_attr_set_interface(void);
+int hp_init_attr_set_interface(void);
+size_t hp_calculate_string_buffer(const char *str);
+size_t hp_calculate_security_buffer(const char *authentication);
+void *hp_ascii_to_utf16_unicode(u16 *p, const u8 *str);
+int hp_get_integer_from_buffer(u8 **buffer, u32 *buffer_size, u32 *integer);
+int hp_get_string_from_buffer(u8 **buffer, u32 *buffer_size, char *dst, u32 dst_size);
+int hp_convert_hexstr_to_str(const char *input, u32 input_len, char **str, int *len);
+int hp_encode_outsize_for_pvsz(int outsize);
+int hp_enforce_single_line_input(char *buf, size_t count);
+void hp_set_reboot_and_signal_event(void);
+ssize_t display_name_language_code_show(struct kobject *kobj,
+ struct kobj_attribute *attr,
+ char *buf);
+union acpi_object *hp_get_wmiobj_pointer(int instance_id, const char *guid_string);
+int hp_get_instance_count(const char *guid_string);
+void hp_update_attribute_permissions(bool isreadonly, struct kobj_attribute *current_val);
+void hp_friendly_user_name_update(char *path, const char *attr_name,
+ char *attr_display, int attr_size);
+int hp_wmi_error_and_message(int error_code);
+
+#endif
--
2.34.1


2023-05-17 16:01:40

by Jorge Lopez

[permalink] [raw]
Subject: [PATCH v14 11/13] hp-bioscfg: surestart-attributes

HP BIOS Configuration driver purpose is to provide a driver supporting
the latest sysfs class firmware attributes framework allowing the user
to change BIOS settings and security solutions on HP Inc.’s commercial
notebooks.

Many features of HP Commercial notebooks can be managed using Windows
Management Instrumentation (WMI). WMI is an implementation of Web-Based
Enterprise Management (WBEM) that provides a standards-based interface
for changing and monitoring system settings. HP BIOSCFG driver provides
a native Linux solution and the exposed features facilitates the
migration to Linux environments.

The Linux security features to be provided in hp-bioscfg driver enables
managing the BIOS settings and security solutions via sysfs, a virtual
filesystem that can be used by user-mode applications. The new
documentation cover HP-specific firmware sysfs attributes such Secure
Platform Management and Sure Start. Each section provides security
feature description and identifies sysfs directories and files exposed
by the driver.

Many HP Commercial notebooks include a feature called Secure Platform
Management (SPM), which replaces older password-based BIOS settings
management with public key cryptography. PC secure product management
begins when a target system is provisioned with cryptographic keys
that are used to ensure the integrity of communications between system
management utilities and the BIOS.

HP Commercial notebooks have several BIOS settings that control its
behaviour and capabilities, many of which are related to security.
To prevent unauthorized changes to these settings, the system can
be configured to use a cryptographic signature-based authorization
string that the BIOS will use to verify authorization to modify the
setting.

Linux Security components are under development and not published yet.
The only linux component is the driver (hp bioscfg) at this time.
Other published security components are under Windows.

Signed-off-by: Jorge Lopez <[email protected]>

---
Based on the latest platform-drivers-x86.git/for-next
---
.../x86/hp/hp-bioscfg/surestart-attributes.c | 132 ++++++++++++++++++
1 file changed, 132 insertions(+)
create mode 100644 drivers/platform/x86/hp/hp-bioscfg/surestart-attributes.c

diff --git a/drivers/platform/x86/hp/hp-bioscfg/surestart-attributes.c b/drivers/platform/x86/hp/hp-bioscfg/surestart-attributes.c
new file mode 100644
index 000000000000..b57e42f29282
--- /dev/null
+++ b/drivers/platform/x86/hp/hp-bioscfg/surestart-attributes.c
@@ -0,0 +1,132 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Functions corresponding to sure start object type attributes under
+ * BIOS for use with hp-bioscfg driver
+ *
+ * Copyright (c) 2022 HP Development Company, L.P.
+ */
+
+#include "bioscfg.h"
+#include <linux/types.h>
+
+/* Maximum number of log entries supported when log entry size is 16
+ * bytes. This value is calculated by dividing 4096 (page size) by
+ * log entry size.
+ */
+#define LOG_MAX_ENTRIES 254
+
+/*
+ * Current Log entry size. This value size will change in the
+ * future. The driver reads a total of 128 bytes for each log entry
+ * provided by BIOS but only the first 16 bytes are used/read.
+ */
+#define LOG_ENTRY_SIZE 16
+
+/*
+ * audit_log_entry_count_show - Reports the number of
+ * existing audit log entries available
+ * to be read
+ */
+static ssize_t audit_log_entry_count_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf)
+{
+ int ret;
+ u32 count = 0;
+
+ ret = hp_wmi_perform_query(HPWMI_SURESTART_GET_LOG_COUNT,
+ HPWMI_SURESTART,
+ &count, 1, sizeof(count));
+
+ if (ret < 0)
+ return ret;
+
+ return sysfs_emit(buf, "%d,%d,%d\n", count, LOG_ENTRY_SIZE,
+ LOG_MAX_ENTRIES);
+}
+
+/*
+ * audit_log_entries_show() - Return all entries found in log file
+ */
+static ssize_t audit_log_entries_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf)
+{
+ int ret;
+ int i;
+ u32 count = 0;
+ u8 audit_log_buffer[128];
+
+ // Get the number of event logs
+ ret = hp_wmi_perform_query(HPWMI_SURESTART_GET_LOG_COUNT,
+ HPWMI_SURESTART,
+ &count, 1, sizeof(count));
+
+ if (ret < 0)
+ return ret;
+
+ /*
+ * The show() api will not work if the audit logs ever go
+ * beyond 4KB
+ */
+ if (count * LOG_ENTRY_SIZE > PAGE_SIZE)
+ return -EIO;
+
+ /*
+ * We are guaranteed the buffer is 4KB so today all the event
+ * logs will fit
+ */
+ for (i = 0; i < count; i++) {
+ audit_log_buffer[0] = i + 1;
+
+ /*
+ * read audit log entry at a time. 'buf' input value
+ * provides the audit log entry to be read. On
+ * input, Byte 0 = Audit Log entry number from
+ * beginning (1..254)
+ * Entry number 1 is the newest entry whereas the
+ * highest entry number (number of entries) is the
+ * oldest entry.
+ */
+ ret = hp_wmi_perform_query(HPWMI_SURESTART_GET_LOG,
+ HPWMI_SURESTART,
+ audit_log_buffer, 1, 128);
+
+ if (ret < 0 || (LOG_ENTRY_SIZE * i) > PAGE_SIZE) {
+ /*
+ * Encountered a failure while reading
+ * individual logs. Only a partial list of
+ * audit log will be returned.
+ */
+ break;
+ } else {
+ memcpy(buf, audit_log_buffer, LOG_ENTRY_SIZE);
+ buf += LOG_ENTRY_SIZE;
+ }
+ }
+
+ return i * LOG_ENTRY_SIZE;
+}
+
+static struct kobj_attribute sure_start_audit_log_entry_count = __ATTR_RO(audit_log_entry_count);
+static struct kobj_attribute sure_start_audit_log_entries = __ATTR_RO(audit_log_entries);
+
+static struct attribute *sure_start_attrs[] = {
+ &sure_start_audit_log_entry_count.attr,
+ &sure_start_audit_log_entries.attr,
+ NULL
+};
+
+static const struct attribute_group sure_start_attr_group = {
+ .attrs = sure_start_attrs,
+};
+
+void hp_exit_sure_start_attributes(void)
+{
+ sysfs_remove_group(bioscfg_drv.sure_start_attr_kobj,
+ &sure_start_attr_group);
+}
+
+int hp_populate_sure_start_data(struct kobject *attr_name_kobj)
+{
+ bioscfg_drv.sure_start_attr_kobj = attr_name_kobj;
+ return sysfs_create_group(attr_name_kobj, &sure_start_attr_group);
+}
--
2.34.1


2023-05-18 00:10:24

by Randy Dunlap

[permalink] [raw]
Subject: Re: [PATCH v14 01/13] hp-bioscfg: Documentation

Hi--

On 5/17/23 08:50, Jorge Lopez wrote:
> HP BIOS Configuration driver purpose is to provide a driver supporting
> the latest sysfs class firmware attributes framework allowing the user
> to change BIOS settings and security solutions on HP Inc.’s commercial
> notebooks.
>
> Many features of HP Commercial notebooks can be managed using Windows
> Management Instrumentation (WMI). WMI is an implementation of Web-Based
> Enterprise Management (WBEM) that provides a standards-based interface
> for changing and monitoring system settings. HP BIOSCFG driver provides
> a native Linux solution and the exposed features facilitates the
> migration to Linux environments.
>
> The Linux security features to be provided in hp-bioscfg driver enables
> managing the BIOS settings and security solutions via sysfs, a virtual
> filesystem that can be used by user-mode applications. The new
> documentation cover HP-specific firmware sysfs attributes such Secure
> Platform Management and Sure Start. Each section provides security
> feature description and identifies sysfs directories and files exposed
> by the driver.
>
> Many HP Commercial notebooks include a feature called Secure Platform
> Management (SPM), which replaces older password-based BIOS settings
> management with public key cryptography. PC secure product management
> begins when a target system is provisioned with cryptographic keys
> that are used to ensure the integrity of communications between system
> management utilities and the BIOS.
>
> HP Commercial notebooks have several BIOS settings that control its
> behaviour and capabilities, many of which are related to security.
> To prevent unauthorized changes to these settings, the system can
> be configured to use a cryptographic signature-based authorization
> string that the BIOS will use to verify authorization to modify the
> setting.
>
> Linux Security components are under development and not published yet.
> The only linux component is the driver (hp bioscfg) at this time.
> Other published security components are under Windows.
>

IMO it doesn't help to have this blurb repeated in each patch.

The commit message should describe what this patch does and why.

> Signed-off-by: Jorge Lopez <[email protected]>
>
> ---
> Based on the latest platform-drivers-x86.git/for-next
> ---
> .../testing/sysfs-class-firmware-attributes | 102 +++++++++++++++++-
> 1 file changed, 100 insertions(+), 2 deletions(-)
>
> diff --git a/Documentation/ABI/testing/sysfs-class-firmware-attributes b/Documentation/ABI/testing/sysfs-class-firmware-attributes
> index 4cdba3477176..f8d6c089228b 100644
> --- a/Documentation/ABI/testing/sysfs-class-firmware-attributes
> +++ b/Documentation/ABI/testing/sysfs-class-firmware-attributes
> @@ -22,6 +22,11 @@ Description:
> - integer: a range of numerical values
> - string
>
> + HP specific types
> + -----------------
> + - ordered-list - a set of ordered list valid values
> +
> +
> All attribute types support the following values:
>
> current_value:
> @@ -126,6 +131,22 @@ Description:
> value will not be effective through sysfs until this rule is
> met.
>
> + HP specific class extensions
> + ------------------------------
> +
> + On HP systems the following additional attributes are available:
> +
> + "ordered-list"-type specific properties:
> +
> + elements:
> + A file that can be read to obtain the possible
> + list of values of the <attr>. Values are separated using
> + semi-colon (``;``). The order individual elements are listed
> + according to their priority. An element listed first has the

I have trouble parsing "The order individual elements are list
according to their property."

> + highest priority. Writing the list in a different order to
> + current_value alters the priority order for the particular
> + attribute.
> +
> What: /sys/class/firmware-attributes/*/authentication/
> Date: February 2021
> KernelVersion: 5.11
> @@ -206,7 +227,7 @@ Description:
> Drivers may emit a CHANGE uevent when a password is set or unset
> userspace may check it again.
>
> - On Dell and Lenovo systems, if Admin password is set, then all BIOS attributes
> + On Dell, Lenovo and HP systems, if Admin password is set, then all BIOS attributes
> require password validation.
> On Lenovo systems if you change the Admin password the new password is not active until
> the next boot.

> @@ -364,3 +394,71 @@ Description:
> use it to enable extra debug attributes or BIOS features for testing purposes.
>
> Note that any changes to this attribute requires a reboot for changes to take effect.
> +
> +
> + HP specific class extensions - Secure Platform Manager (SPM)
> + --------------------------------
> +
> +What: /sys/class/firmware-attributes/*/authentication/SPM/kek
> +Date: March 29

Date: should be Month Year or Month Day Year according to other files
(although it is apparently not specified as far as my quick searching
found).

> +KernelVersion: 5.18
> +Contact: "Jorge Lopez" <[email protected]>
> +Description:
> + 'kek' Key-Encryption-Key is a write-only file that can be used to configure the
> + RSA public key that will be used by the BIOS to verify
> + signatures when setting the signing key. When written,
> + the bytes should correspond to the KEK certificate
> + (x509 .DER format containing an OU). The size of the
> + certificate must be less than or equal to 4095 bytes.
> +
> +What: /sys/class/firmware-attributes/*/authentication/SPM/sk
> +Date: March 29

Ditto.

> +KernelVersion: 5.18
> +Contact: "Jorge Lopez" <[email protected]>
> +Description:
> + 'sk' Signature Key is a write-only file that can be used to configure the RSA
> + public key that will be used by the BIOS to verify signatures
> + when configuring BIOS settings and security features. When
> + written, the bytes should correspond to the modulus of the
> + public key. The exponent is assumed to be 0x10001.
> +
> +What: /sys/class/firmware-attributes/*/authentication/SPM/status
> +Date: March 29

Ditto.

> +KernelVersion: 5.18
> +Contact: "Jorge Lopez" <[email protected]>
> +Description:
> + 'status' is a read-only file that returns ASCII text in JSON format reporting
> + the status information.
> +
> + "State": "not provisioned | provisioned | provisioning in progress ",
> + "Version": " Major. Minor ",
> + "Nonce": <16-bit unsigned number display in base 10>,
> + "FeaturesInUse": <16-bit unsigned number display in base 10>,
> + "EndorsementKeyMod": "<256 bytes in base64>",
> + "SigningKeyMod": "<256 bytes in base64>"
> +
> +What: /sys/class/firmware-attributes/*/attributes/Sure_Start/audit_log_entries
> +Date: March 29

Ditto.

> +KernelVersion: 5.18
> +Contact: "Jorge Lopez" <[email protected]>
> +Description:
> + 'audit_log_entries' is a read-only file that returns the events in the log.
> +
> + Audit log entry format
> +
> + Byte 0-15: Requested Audit Log entry (Each Audit log is 16 bytes)
> + Byte 16-127: Unused
> +
> +What: /sys/class/firmware-attributes/*/attributes/Sure_Start/audit_log_entry_count
> +Date: March 29

Ditto.

> +KernelVersion: 5.18
> +Contact: "Jorge Lopez" <[email protected]>
> +Description:
> + 'audit_log_entry_count' is a read-only file that returns the number of existing
> + audit log events available to be read. Values are separated using comma (``,``)
> +
> + [No of entries],[log entry size],[Max number of entries supported]
> +
> + log entry size identifies audit log size for the current BIOS version.
> + The current size is 16 bytes but it can be up to 128 bytes long in future BIOS
> + versions.

2023-05-18 16:34:11

by Jorge Lopez

[permalink] [raw]
Subject: Re: [PATCH v14 01/13] hp-bioscfg: Documentation

On Wed, May 17, 2023 at 6:42 PM Randy Dunlap <[email protected]> wrote:
>
> Hi--
>
> On 5/17/23 08:50, Jorge Lopez wrote:
> > HP BIOS Configuration driver purpose is to provide a driver supporting
> > the latest sysfs class firmware attributes framework allowing the user
> > to change BIOS settings and security solutions on HP Inc.’s commercial
> > notebooks.
> >
> > Many features of HP Commercial notebooks can be managed using Windows
> > Management Instrumentation (WMI). WMI is an implementation of Web-Based
> > Enterprise Management (WBEM) that provides a standards-based interface
> > for changing and monitoring system settings. HP BIOSCFG driver provides
> > a native Linux solution and the exposed features facilitates the
> > migration to Linux environments.
> >
> > The Linux security features to be provided in hp-bioscfg driver enables
> > managing the BIOS settings and security solutions via sysfs, a virtual
> > filesystem that can be used by user-mode applications. The new
> > documentation cover HP-specific firmware sysfs attributes such Secure
> > Platform Management and Sure Start. Each section provides security
> > feature description and identifies sysfs directories and files exposed
> > by the driver.
> >
> > Many HP Commercial notebooks include a feature called Secure Platform
> > Management (SPM), which replaces older password-based BIOS settings
> > management with public key cryptography. PC secure product management
> > begins when a target system is provisioned with cryptographic keys
> > that are used to ensure the integrity of communications between system
> > management utilities and the BIOS.
> >
> > HP Commercial notebooks have several BIOS settings that control its
> > behaviour and capabilities, many of which are related to security.
> > To prevent unauthorized changes to these settings, the system can
> > be configured to use a cryptographic signature-based authorization
> > string that the BIOS will use to verify authorization to modify the
> > setting.
> >
> > Linux Security components are under development and not published yet.
> > The only linux component is the driver (hp bioscfg) at this time.
> > Other published security components are under Windows.
> >
>
> IMO it doesn't help to have this blurb repeated in each patch.
>
> The commit message should describe what this patch does and why.
>
> > Signed-off-by: Jorge Lopez <[email protected]>
> >
> > ---
> > Based on the latest platform-drivers-x86.git/for-next
> > ---
> > .../testing/sysfs-class-firmware-attributes | 102 +++++++++++++++++-
> > 1 file changed, 100 insertions(+), 2 deletions(-)
> >
> > diff --git a/Documentation/ABI/testing/sysfs-class-firmware-attributes b/Documentation/ABI/testing/sysfs-class-firmware-attributes
> > index 4cdba3477176..f8d6c089228b 100644
> > --- a/Documentation/ABI/testing/sysfs-class-firmware-attributes
> > +++ b/Documentation/ABI/testing/sysfs-class-firmware-attributes
> > @@ -22,6 +22,11 @@ Description:
> > - integer: a range of numerical values
> > - string
> >
> > + HP specific types
> > + -----------------
> > + - ordered-list - a set of ordered list valid values
> > +
> > +
> > All attribute types support the following values:
> >
> > current_value:
> > @@ -126,6 +131,22 @@ Description:
> > value will not be effective through sysfs until this rule is
> > met.
> >
> > + HP specific class extensions
> > + ------------------------------
> > +
> > + On HP systems the following additional attributes are available:
> > +
> > + "ordered-list"-type specific properties:
> > +
> > + elements:
> > + A file that can be read to obtain the possible
> > + list of values of the <attr>. Values are separated using
> > + semi-colon (``;``). The order individual elements are listed
> > + according to their priority. An element listed first has the
>
> I have trouble parsing "The order individual elements are list
> according to their property."

I will update the text and provide a more comprehensive statement.
For instance... "Values are separated using semi-colon (``;``) and
listed according to their priority."
>
> > + highest priority. Writing the list in a different order to
> > + current_value alters the priority order for the particular
> > + attribute.
> > +
> > What: /sys/class/firmware-attributes/*/authentication/
> > Date: February 2021
> > KernelVersion: 5.11
> > @@ -206,7 +227,7 @@ Description:
> > Drivers may emit a CHANGE uevent when a password is set or unset
> > userspace may check it again.
> >
> > - On Dell and Lenovo systems, if Admin password is set, then all BIOS attributes
> > + On Dell, Lenovo and HP systems, if Admin password is set, then all BIOS attributes
> > require password validation.
> > On Lenovo systems if you change the Admin password the new password is not active until
> > the next boot.
>
> > @@ -364,3 +394,71 @@ Description:
> > use it to enable extra debug attributes or BIOS features for testing purposes.
> >
> > Note that any changes to this attribute requires a reboot for changes to take effect.
> > +
> > +
> > + HP specific class extensions - Secure Platform Manager (SPM)
> > + --------------------------------
> > +
> > +What: /sys/class/firmware-attributes/*/authentication/SPM/kek
> > +Date: March 29
>
> Date: should be Month Year or Month Day Year according to other files
> (although it is apparently not specified as far as my quick searching
> found).

Date format will be changed to Month Year across the file.
Thank you.
>
> > +KernelVersion: 5.18
> > +Contact: "Jorge Lopez" <[email protected]>
> > +Description:
> > + 'kek' Key-Encryption-Key is a write-only file that can be used to configure the
> > + RSA public key that will be used by the BIOS to verify
> > + signatures when setting the signing key. When written,
> > + the bytes should correspond to the KEK certificate
> > + (x509 .DER format containing an OU). The size of the
> > + certificate must be less than or equal to 4095 bytes.
> > +
> > +What: /sys/class/firmware-attributes/*/authentication/SPM/sk
> > +Date: March 29
>
> Ditto.
>
> > +KernelVersion: 5.18
> > +Contact: "Jorge Lopez" <[email protected]>
> > +Description:
> > + 'sk' Signature Key is a write-only file that can be used to configure the RSA
> > + public key that will be used by the BIOS to verify signatures
> > + when configuring BIOS settings and security features. When
> > + written, the bytes should correspond to the modulus of the
> > + public key. The exponent is assumed to be 0x10001.
> > +
> > +What: /sys/class/firmware-attributes/*/authentication/SPM/status
> > +Date: March 29
>
> Ditto.
>
> > +KernelVersion: 5.18
> > +Contact: "Jorge Lopez" <[email protected]>
> > +Description:
> > + 'status' is a read-only file that returns ASCII text in JSON format reporting
> > + the status information.
> > +
> > + "State": "not provisioned | provisioned | provisioning in progress ",
> > + "Version": " Major. Minor ",
> > + "Nonce": <16-bit unsigned number display in base 10>,
> > + "FeaturesInUse": <16-bit unsigned number display in base 10>,
> > + "EndorsementKeyMod": "<256 bytes in base64>",
> > + "SigningKeyMod": "<256 bytes in base64>"
> > +
> > +What: /sys/class/firmware-attributes/*/attributes/Sure_Start/audit_log_entries
> > +Date: March 29
>
> Ditto.
>
> > +KernelVersion: 5.18
> > +Contact: "Jorge Lopez" <[email protected]>
> > +Description:
> > + 'audit_log_entries' is a read-only file that returns the events in the log.
> > +
> > + Audit log entry format
> > +
> > + Byte 0-15: Requested Audit Log entry (Each Audit log is 16 bytes)
> > + Byte 16-127: Unused
> > +
> > +What: /sys/class/firmware-attributes/*/attributes/Sure_Start/audit_log_entry_count
> > +Date: March 29
>
> Ditto.
>
> > +KernelVersion: 5.18
> > +Contact: "Jorge Lopez" <[email protected]>
> > +Description:
> > + 'audit_log_entry_count' is a read-only file that returns the number of existing
> > + audit log events available to be read. Values are separated using comma (``,``)
> > +
> > + [No of entries],[log entry size],[Max number of entries supported]
> > +
> > + log entry size identifies audit log size for the current BIOS version.
> > + The current size is 16 bytes but it can be up to 128 bytes long in future BIOS
> > + versions.

2023-05-19 17:37:36

by Mark Pearson

[permalink] [raw]
Subject: Re: [PATCH v14 01/13] hp-bioscfg: Documentation

Hi Jorge,

On Wed, May 17, 2023, at 11:50 AM, Jorge Lopez wrote:
> HP BIOS Configuration driver purpose is to provide a driver supporting
> the latest sysfs class firmware attributes framework allowing the user
> to change BIOS settings and security solutions on HP Inc.’s commercial
> notebooks.
>
> Many features of HP Commercial notebooks can be managed using Windows
> Management Instrumentation (WMI). WMI is an implementation of Web-Based
> Enterprise Management (WBEM) that provides a standards-based interface
> for changing and monitoring system settings. HP BIOSCFG driver provides
> a native Linux solution and the exposed features facilitates the
> migration to Linux environments.
>
> The Linux security features to be provided in hp-bioscfg driver enables
> managing the BIOS settings and security solutions via sysfs, a virtual
> filesystem that can be used by user-mode applications. The new
> documentation cover HP-specific firmware sysfs attributes such Secure
> Platform Management and Sure Start. Each section provides security
> feature description and identifies sysfs directories and files exposed
> by the driver.
>
> Many HP Commercial notebooks include a feature called Secure Platform
> Management (SPM), which replaces older password-based BIOS settings
> management with public key cryptography. PC secure product management
> begins when a target system is provisioned with cryptographic keys
> that are used to ensure the integrity of communications between system
> management utilities and the BIOS.
>
> HP Commercial notebooks have several BIOS settings that control its
> behaviour and capabilities, many of which are related to security.
> To prevent unauthorized changes to these settings, the system can
> be configured to use a cryptographic signature-based authorization
> string that the BIOS will use to verify authorization to modify the
> setting.
>
> Linux Security components are under development and not published yet.
> The only linux component is the driver (hp bioscfg) at this time.
> Other published security components are under Windows.
>
> Signed-off-by: Jorge Lopez <[email protected]>
>
> ---
> Based on the latest platform-drivers-x86.git/for-next
> ---
> .../testing/sysfs-class-firmware-attributes | 102 +++++++++++++++++-
> 1 file changed, 100 insertions(+), 2 deletions(-)
>
> diff --git a/Documentation/ABI/testing/sysfs-class-firmware-attributes
> b/Documentation/ABI/testing/sysfs-class-firmware-attributes
> index 4cdba3477176..f8d6c089228b 100644
> --- a/Documentation/ABI/testing/sysfs-class-firmware-attributes
> +++ b/Documentation/ABI/testing/sysfs-class-firmware-attributes
<snip>
> +
> +
> + HP specific class extensions - Secure Platform Manager (SPM)
> + --------------------------------
> +
> +What: /sys/class/firmware-attributes/*/authentication/SPM/kek
> +Date: March 29
> +KernelVersion: 5.18
> +Contact: "Jorge Lopez" <[email protected]>
> +Description:
> + 'kek' Key-Encryption-Key is a write-only file that can be used to
> configure the
> + RSA public key that will be used by the BIOS to verify
> + signatures when setting the signing key. When written,
> + the bytes should correspond to the KEK certificate
> + (x509 .DER format containing an OU). The size of the
> + certificate must be less than or equal to 4095 bytes.
> +
> +What: /sys/class/firmware-attributes/*/authentication/SPM/sk
> +Date: March 29
> +KernelVersion: 5.18
> +Contact: "Jorge Lopez" <[email protected]>
> +Description:
> + 'sk' Signature Key is a write-only file that can be used to
> configure the RSA
> + public key that will be used by the BIOS to verify signatures
> + when configuring BIOS settings and security features. When
> + written, the bytes should correspond to the modulus of the
> + public key. The exponent is assumed to be 0x10001.
> +
> +What: /sys/class/firmware-attributes/*/authentication/SPM/status
> +Date: March 29
> +KernelVersion: 5.18
> +Contact: "Jorge Lopez" <[email protected]>
> +Description:
> + 'status' is a read-only file that returns ASCII text in JSON format
> reporting
> + the status information.
> +
> + "State": "not provisioned | provisioned | provisioning in progress
> ",
> + "Version": " Major. Minor ",
> + "Nonce": <16-bit unsigned number display in base 10>,
> + "FeaturesInUse": <16-bit unsigned number display in base 10>,
> + "EndorsementKeyMod": "<256 bytes in base64>",
> + "SigningKeyMod": "<256 bytes in base64>"
> +
> +What: /sys/class/firmware-attributes/*/attributes/Sure_Start/audit_log_entries
> +Date: March 29
> +KernelVersion: 5.18
> +Contact: "Jorge Lopez" <[email protected]>
> +Description:
> + 'audit_log_entries' is a read-only file that returns the events in
> the log.
> +
> + Audit log entry format
> +
> + Byte 0-15: Requested Audit Log entry (Each Audit log is 16 bytes)
> + Byte 16-127: Unused
> +
> +What: /sys/class/firmware-attributes/*/attributes/Sure_Start/audit_log_entry_count
> +Date: March 29
> +KernelVersion: 5.18
> +Contact: "Jorge Lopez" <[email protected]>
> +Description:
> + 'audit_log_entry_count' is a read-only file that returns the number
> of existing
> + audit log events available to be read. Values are separated using
> comma (``,``)
> +
> + [No of entries],[log entry size],[Max number of entries supported]
> +
> + log entry size identifies audit log size for the current BIOS
> version.
> + The current size is 16 bytes but it can be up to 128 bytes long in
> future BIOS
> + versions.
> --
> 2.34.1

Firstly apologies as I've done a poor job of following the updates to this series - so if this has already been discussed and agreed by more seasoned kernel contributors please feel free to disregard my comments :) I was catching up on my inbox and had some thoughts.

For SPM - as this replaces password usage, is it done for all account types? It seems a bit odd having it be a replacement for the passwords but in it's own location and not in the same place as (for example) Admin/current_password.
For the Lenovo implementation I put certificate, signature and save_signature in the authentication/Admin directory and I realise your implementation is different with the keys but if the kek and sk are only used with the Admin account then shouldn't they also be in that directory? It would be nice to have some commonality across vendors in my opinion.

For the Sure_Start I would propose de-branding this so it's generic and I don't think it fits under attributes as it doesn't support any of the other required attribute fields. I think your implementation of an audit log seems neat but if another vendor was to do similar it would be better to be able to reuse the same attribute name and enable common tooling.
I propose having this as just log/audit_entries and log/audit_count and have the log folder in the top alongside authentication and attributes.
If someone wants to add other logs in the future it would be a good place to have them.

Thanks
Mark

2023-05-19 21:07:56

by Jorge Lopez

[permalink] [raw]
Subject: Re: [PATCH v14 01/13] hp-bioscfg: Documentation

On Fri, May 19, 2023 at 12:34 PM Mark Pearson <[email protected]> wrote:
>
> Hi Jorge,
>
> On Wed, May 17, 2023, at 11:50 AM, Jorge Lopez wrote:
> > HP BIOS Configuration driver purpose is to provide a driver supporting
> > the latest sysfs class firmware attributes framework allowing the user
> > to change BIOS settings and security solutions on HP Inc.’s commercial
> > notebooks.
> >
> > Many features of HP Commercial notebooks can be managed using Windows
> > Management Instrumentation (WMI). WMI is an implementation of Web-Based
> > Enterprise Management (WBEM) that provides a standards-based interface
> > for changing and monitoring system settings. HP BIOSCFG driver provides
> > a native Linux solution and the exposed features facilitates the
> > migration to Linux environments.
> >
> > The Linux security features to be provided in hp-bioscfg driver enables
> > managing the BIOS settings and security solutions via sysfs, a virtual
> > filesystem that can be used by user-mode applications. The new
> > documentation cover HP-specific firmware sysfs attributes such Secure
> > Platform Management and Sure Start. Each section provides security
> > feature description and identifies sysfs directories and files exposed
> > by the driver.
> >
> > Many HP Commercial notebooks include a feature called Secure Platform
> > Management (SPM), which replaces older password-based BIOS settings
> > management with public key cryptography. PC secure product management
> > begins when a target system is provisioned with cryptographic keys
> > that are used to ensure the integrity of communications between system
> > management utilities and the BIOS.
> >
> > HP Commercial notebooks have several BIOS settings that control its
> > behaviour and capabilities, many of which are related to security.
> > To prevent unauthorized changes to these settings, the system can
> > be configured to use a cryptographic signature-based authorization
> > string that the BIOS will use to verify authorization to modify the
> > setting.
> >
> > Linux Security components are under development and not published yet.
> > The only linux component is the driver (hp bioscfg) at this time.
> > Other published security components are under Windows.
> >
> > Signed-off-by: Jorge Lopez <[email protected]>
> >
> > ---
> > Based on the latest platform-drivers-x86.git/for-next
> > ---
> > .../testing/sysfs-class-firmware-attributes | 102 +++++++++++++++++-
> > 1 file changed, 100 insertions(+), 2 deletions(-)
> >
> > diff --git a/Documentation/ABI/testing/sysfs-class-firmware-attributes
> > b/Documentation/ABI/testing/sysfs-class-firmware-attributes
> > index 4cdba3477176..f8d6c089228b 100644
> > --- a/Documentation/ABI/testing/sysfs-class-firmware-attributes
> > +++ b/Documentation/ABI/testing/sysfs-class-firmware-attributes
> <snip>
> > +
> > +
> > + HP specific class extensions - Secure Platform Manager (SPM)
> > + --------------------------------
> > +
> > +What: /sys/class/firmware-attributes/*/authentication/SPM/kek
> > +Date: March 29
> > +KernelVersion: 5.18
> > +Contact: "Jorge Lopez" <[email protected]>
> > +Description:
> > + 'kek' Key-Encryption-Key is a write-only file that can be used to
> > configure the
> > + RSA public key that will be used by the BIOS to verify
> > + signatures when setting the signing key. When written,
> > + the bytes should correspond to the KEK certificate
> > + (x509 .DER format containing an OU). The size of the
> > + certificate must be less than or equal to 4095 bytes.
> > +
> > +What: /sys/class/firmware-attributes/*/authentication/SPM/sk
> > +Date: March 29
> > +KernelVersion: 5.18
> > +Contact: "Jorge Lopez" <[email protected]>
> > +Description:
> > + 'sk' Signature Key is a write-only file that can be used to
> > configure the RSA
> > + public key that will be used by the BIOS to verify signatures
> > + when configuring BIOS settings and security features. When
> > + written, the bytes should correspond to the modulus of the
> > + public key. The exponent is assumed to be 0x10001.
> > +
> > +What: /sys/class/firmware-attributes/*/authentication/SPM/status
> > +Date: March 29
> > +KernelVersion: 5.18
> > +Contact: "Jorge Lopez" <[email protected]>
> > +Description:
> > + 'status' is a read-only file that returns ASCII text in JSON format
> > reporting
> > + the status information.
> > +
> > + "State": "not provisioned | provisioned | provisioning in progress
> > ",
> > + "Version": " Major. Minor ",
> > + "Nonce": <16-bit unsigned number display in base 10>,
> > + "FeaturesInUse": <16-bit unsigned number display in base 10>,
> > + "EndorsementKeyMod": "<256 bytes in base64>",
> > + "SigningKeyMod": "<256 bytes in base64>"
> > +
> > +What: /sys/class/firmware-attributes/*/attributes/Sure_Start/audit_log_entries
> > +Date: March 29
> > +KernelVersion: 5.18
> > +Contact: "Jorge Lopez" <[email protected]>
> > +Description:
> > + 'audit_log_entries' is a read-only file that returns the events in
> > the log.
> > +
> > + Audit log entry format
> > +
> > + Byte 0-15: Requested Audit Log entry (Each Audit log is 16 bytes)
> > + Byte 16-127: Unused
> > +
> > +What: /sys/class/firmware-attributes/*/attributes/Sure_Start/audit_log_entry_count
> > +Date: March 29
> > +KernelVersion: 5.18
> > +Contact: "Jorge Lopez" <[email protected]>
> > +Description:
> > + 'audit_log_entry_count' is a read-only file that returns the number
> > of existing
> > + audit log events available to be read. Values are separated using
> > comma (``,``)
> > +
> > + [No of entries],[log entry size],[Max number of entries supported]
> > +
> > + log entry size identifies audit log size for the current BIOS
> > version.
> > + The current size is 16 bytes but it can be up to 128 bytes long in
> > future BIOS
> > + versions.
> > --
> > 2.34.1
>
> Firstly apologies as I've done a poor job of following the updates to this series - so if this has already been discussed and agreed by more seasoned kernel contributors please feel free to disregard my comments :) I was catching up on my inbox and had some thoughts.

No worries.

>
> For SPM - as this replaces password usage, is it done for all account types? It seems a bit odd having it be a replacement for the passwords but in it's own location and not in the same place as (for example) Admin/current_password.
> For the Lenovo implementation I put certificate, signature and save_signature in the authentication/Admin directory and I realise your implementation is different with the keys but if the kek and sk are only used with the Admin account then shouldn't they also be in that directory? It would be nice to have some commonality across vendors in my opinion.
>

SPM (Security Platform Management) does not replace password usage and
it is done for the Admin account (Setup Password). SPM is a security
feature available to the user to configure/update BIOS settings when
Sure Admin is enabled in BIOS. One of the files provided under SPM is
the key _role and its value is set to ‘bios-spm.’ A ‘bios-spm’ role
indicates a password is used in combination with an
endorsement/signing key. It is also the reason why SPM is kept
separate under the list of authentication attributes.

> For the Sure_Start I would propose de-branding this so it's generic and I don't think it fits under attributes as it doesn't support any of the other required attribute fields. I think your implementation of an audit log seems neat but if another vendor was to do similar it would be better to be able to reuse the same attribute name and enable common tooling.
> I propose having this as just log/audit_entries and log/audit_count and have the log folder in the top alongside authentication and attributes.
> If someone wants to add other logs in the future it would be a good place to have them.

I like the idea of having a log folder alongside authentication and
attributes where future logs can be placed. Unfortunately, Sure_Start
is part of the security attributes and the initial driver provides a
minimal implementation. Other attributes associated with Sure_Start
and available in BIOS are 'SureStart Production Mode', 'Sure Start
Security Event Boot Notification', 'Sure Start BIOS Settings
Protection', 'Sure Start Secure Boot Keys Protection', and 'Sure Start
Security Event Policy'

>
> Thanks
> Mark

2023-05-19 23:40:50

by Mark Pearson

[permalink] [raw]
Subject: Re: [PATCH v14 01/13] hp-bioscfg: Documentation

Thanks Jorge,

On Fri, May 19, 2023, at 4:58 PM, Jorge Lopez wrote:
> On Fri, May 19, 2023 at 12:34 PM Mark Pearson <[email protected]> wrote:
>>
>> Hi Jorge,
>>
>> On Wed, May 17, 2023, at 11:50 AM, Jorge Lopez wrote:
>> > HP BIOS Configuration driver purpose is to provide a driver supporting
>> > the latest sysfs class firmware attributes framework allowing the user
>> > to change BIOS settings and security solutions on HP Inc.’s commercial
>> > notebooks.
>> >
>> > Many features of HP Commercial notebooks can be managed using Windows
>> > Management Instrumentation (WMI). WMI is an implementation of Web-Based
>> > Enterprise Management (WBEM) that provides a standards-based interface
>> > for changing and monitoring system settings. HP BIOSCFG driver provides
>> > a native Linux solution and the exposed features facilitates the
>> > migration to Linux environments.
>> >
>> > The Linux security features to be provided in hp-bioscfg driver enables
>> > managing the BIOS settings and security solutions via sysfs, a virtual
>> > filesystem that can be used by user-mode applications. The new
>> > documentation cover HP-specific firmware sysfs attributes such Secure
>> > Platform Management and Sure Start. Each section provides security
>> > feature description and identifies sysfs directories and files exposed
>> > by the driver.
>> >
>> > Many HP Commercial notebooks include a feature called Secure Platform
>> > Management (SPM), which replaces older password-based BIOS settings
>> > management with public key cryptography. PC secure product management
>> > begins when a target system is provisioned with cryptographic keys
>> > that are used to ensure the integrity of communications between system
>> > management utilities and the BIOS.
>> >
>> > HP Commercial notebooks have several BIOS settings that control its
>> > behaviour and capabilities, many of which are related to security.
>> > To prevent unauthorized changes to these settings, the system can
>> > be configured to use a cryptographic signature-based authorization
>> > string that the BIOS will use to verify authorization to modify the
>> > setting.
>> >
>> > Linux Security components are under development and not published yet.
>> > The only linux component is the driver (hp bioscfg) at this time.
>> > Other published security components are under Windows.
>> >
>> > Signed-off-by: Jorge Lopez <[email protected]>
>> >
>> > ---
>> > Based on the latest platform-drivers-x86.git/for-next
>> > ---
>> > .../testing/sysfs-class-firmware-attributes | 102 +++++++++++++++++-
>> > 1 file changed, 100 insertions(+), 2 deletions(-)
>> >
>> > diff --git a/Documentation/ABI/testing/sysfs-class-firmware-attributes
>> > b/Documentation/ABI/testing/sysfs-class-firmware-attributes
>> > index 4cdba3477176..f8d6c089228b 100644
>> > --- a/Documentation/ABI/testing/sysfs-class-firmware-attributes
>> > +++ b/Documentation/ABI/testing/sysfs-class-firmware-attributes
>> <snip>
>> > +
>> > +
>> > + HP specific class extensions - Secure Platform Manager (SPM)
>> > + --------------------------------
>> > +
>> > +What: /sys/class/firmware-attributes/*/authentication/SPM/kek
>> > +Date: March 29
>> > +KernelVersion: 5.18
>> > +Contact: "Jorge Lopez" <[email protected]>
>> > +Description:
>> > + 'kek' Key-Encryption-Key is a write-only file that can be used to
>> > configure the
>> > + RSA public key that will be used by the BIOS to verify
>> > + signatures when setting the signing key. When written,
>> > + the bytes should correspond to the KEK certificate
>> > + (x509 .DER format containing an OU). The size of the
>> > + certificate must be less than or equal to 4095 bytes.
>> > +
>> > +What: /sys/class/firmware-attributes/*/authentication/SPM/sk
>> > +Date: March 29
>> > +KernelVersion: 5.18
>> > +Contact: "Jorge Lopez" <[email protected]>
>> > +Description:
>> > + 'sk' Signature Key is a write-only file that can be used to
>> > configure the RSA
>> > + public key that will be used by the BIOS to verify signatures
>> > + when configuring BIOS settings and security features. When
>> > + written, the bytes should correspond to the modulus of the
>> > + public key. The exponent is assumed to be 0x10001.
>> > +
>> > +What: /sys/class/firmware-attributes/*/authentication/SPM/status
>> > +Date: March 29
>> > +KernelVersion: 5.18
>> > +Contact: "Jorge Lopez" <[email protected]>
>> > +Description:
>> > + 'status' is a read-only file that returns ASCII text in JSON format
>> > reporting
>> > + the status information.
>> > +
>> > + "State": "not provisioned | provisioned | provisioning in progress
>> > ",
>> > + "Version": " Major. Minor ",
>> > + "Nonce": <16-bit unsigned number display in base 10>,
>> > + "FeaturesInUse": <16-bit unsigned number display in base 10>,
>> > + "EndorsementKeyMod": "<256 bytes in base64>",
>> > + "SigningKeyMod": "<256 bytes in base64>"
>> > +
>> > +What: /sys/class/firmware-attributes/*/attributes/Sure_Start/audit_log_entries
>> > +Date: March 29
>> > +KernelVersion: 5.18
>> > +Contact: "Jorge Lopez" <[email protected]>
>> > +Description:
>> > + 'audit_log_entries' is a read-only file that returns the events in
>> > the log.
>> > +
>> > + Audit log entry format
>> > +
>> > + Byte 0-15: Requested Audit Log entry (Each Audit log is 16 bytes)
>> > + Byte 16-127: Unused
>> > +
>> > +What: /sys/class/firmware-attributes/*/attributes/Sure_Start/audit_log_entry_count
>> > +Date: March 29
>> > +KernelVersion: 5.18
>> > +Contact: "Jorge Lopez" <[email protected]>
>> > +Description:
>> > + 'audit_log_entry_count' is a read-only file that returns the number
>> > of existing
>> > + audit log events available to be read. Values are separated using
>> > comma (``,``)
>> > +
>> > + [No of entries],[log entry size],[Max number of entries supported]
>> > +
>> > + log entry size identifies audit log size for the current BIOS
>> > version.
>> > + The current size is 16 bytes but it can be up to 128 bytes long in
>> > future BIOS
>> > + versions.
>> > --
>> > 2.34.1
>>
>> Firstly apologies as I've done a poor job of following the updates to this series - so if this has already been discussed and agreed by more seasoned kernel contributors please feel free to disregard my comments :) I was catching up on my inbox and had some thoughts.
>
> No worries.
>
>>
>> For SPM - as this replaces password usage, is it done for all account types? It seems a bit odd having it be a replacement for the passwords but in it's own location and not in the same place as (for example) Admin/current_password.
>> For the Lenovo implementation I put certificate, signature and save_signature in the authentication/Admin directory and I realise your implementation is different with the keys but if the kek and sk are only used with the Admin account then shouldn't they also be in that directory? It would be nice to have some commonality across vendors in my opinion.
>>
>
> SPM (Security Platform Management) does not replace password usage and
> it is done for the Admin account (Setup Password). SPM is a security
> feature available to the user to configure/update BIOS settings when
> Sure Admin is enabled in BIOS. One of the files provided under SPM is
> the key _role and its value is set to ‘bios-spm.’ A ‘bios-spm’ role
> indicates a password is used in combination with an
> endorsement/signing key. It is also the reason why SPM is kept
> separate under the list of authentication attributes.

Ah - I think I get it, and in that case I can see why you keep it separate and it is a unique role.
I withdraw my suggestion :)

>
>> For the Sure_Start I would propose de-branding this so it's generic and I don't think it fits under attributes as it doesn't support any of the other required attribute fields. I think your implementation of an audit log seems neat but if another vendor was to do similar it would be better to be able to reuse the same attribute name and enable common tooling.
>> I propose having this as just log/audit_entries and log/audit_count and have the log folder in the top alongside authentication and attributes.
>> If someone wants to add other logs in the future it would be a good place to have them.
>
> I like the idea of having a log folder alongside authentication and
> attributes where future logs can be placed. Unfortunately, Sure_Start
> is part of the security attributes and the initial driver provides a
> minimal implementation. Other attributes associated with Sure_Start
> and available in BIOS are 'SureStart Production Mode', 'Sure Start
> Security Event Boot Notification', 'Sure Start BIOS Settings
> Protection', 'Sure Start Secure Boot Keys Protection', and 'Sure Start
> Security Event Policy'

Aren't all of these just regular attributes that show up under the attributes folder (and have current_value and possible_value settings etc)? Do they get created in your equivalent of probing the BIOS to determine what attributes are available or are they manually created entries? (I'm assuming automatic or they would be also added to the documentation)

It seemed to me the audit log entries were being handled differently because you had to specifically create the entries, with (I assume) some special handling for display?

Mark

2023-05-23 14:32:22

by Jorge Lopez

[permalink] [raw]
Subject: Re: [PATCH v14 01/13] hp-bioscfg: Documentation

On Fri, May 19, 2023 at 6:19 PM Mark Pearson <[email protected]> wrote:
>
> Thanks Jorge,
>
> On Fri, May 19, 2023, at 4:58 PM, Jorge Lopez wrote:
> > On Fri, May 19, 2023 at 12:34 PM Mark Pearson <[email protected]> wrote:
> >>
> >> Hi Jorge,
> >>
> >> On Wed, May 17, 2023, at 11:50 AM, Jorge Lopez wrote:
> >> > HP BIOS Configuration driver purpose is to provide a driver supporting
> >> > the latest sysfs class firmware attributes framework allowing the user
> >> > to change BIOS settings and security solutions on HP Inc.’s commercial
> >> > notebooks.
> >> >
> >> > Many features of HP Commercial notebooks can be managed using Windows
> >> > Management Instrumentation (WMI). WMI is an implementation of Web-Based
> >> > Enterprise Management (WBEM) that provides a standards-based interface
> >> > for changing and monitoring system settings. HP BIOSCFG driver provides
> >> > a native Linux solution and the exposed features facilitates the
> >> > migration to Linux environments.
> >> >
> >> > The Linux security features to be provided in hp-bioscfg driver enables
> >> > managing the BIOS settings and security solutions via sysfs, a virtual
> >> > filesystem that can be used by user-mode applications. The new
> >> > documentation cover HP-specific firmware sysfs attributes such Secure
> >> > Platform Management and Sure Start. Each section provides security
> >> > feature description and identifies sysfs directories and files exposed
> >> > by the driver.
> >> >
> >> > Many HP Commercial notebooks include a feature called Secure Platform
> >> > Management (SPM), which replaces older password-based BIOS settings
> >> > management with public key cryptography. PC secure product management
> >> > begins when a target system is provisioned with cryptographic keys
> >> > that are used to ensure the integrity of communications between system
> >> > management utilities and the BIOS.
> >> >
> >> > HP Commercial notebooks have several BIOS settings that control its
> >> > behaviour and capabilities, many of which are related to security.
> >> > To prevent unauthorized changes to these settings, the system can
> >> > be configured to use a cryptographic signature-based authorization
> >> > string that the BIOS will use to verify authorization to modify the
> >> > setting.
> >> >
> >> > Linux Security components are under development and not published yet.
> >> > The only linux component is the driver (hp bioscfg) at this time.
> >> > Other published security components are under Windows.
> >> >
> >> > Signed-off-by: Jorge Lopez <[email protected]>
> >> >
> >> > ---
> >> > Based on the latest platform-drivers-x86.git/for-next
> >> > ---
> >> > .../testing/sysfs-class-firmware-attributes | 102 +++++++++++++++++-
> >> > 1 file changed, 100 insertions(+), 2 deletions(-)
> >> >
> >> > diff --git a/Documentation/ABI/testing/sysfs-class-firmware-attributes
> >> > b/Documentation/ABI/testing/sysfs-class-firmware-attributes
> >> > index 4cdba3477176..f8d6c089228b 100644
> >> > --- a/Documentation/ABI/testing/sysfs-class-firmware-attributes
> >> > +++ b/Documentation/ABI/testing/sysfs-class-firmware-attributes
> >> <snip>
> >> > +
> >> > +
> >> > + HP specific class extensions - Secure Platform Manager (SPM)
> >> > + --------------------------------
> >> > +
> >> > +What: /sys/class/firmware-attributes/*/authentication/SPM/kek
> >> > +Date: March 29
> >> > +KernelVersion: 5.18
> >> > +Contact: "Jorge Lopez" <[email protected]>
> >> > +Description:
> >> > + 'kek' Key-Encryption-Key is a write-only file that can be used to
> >> > configure the
> >> > + RSA public key that will be used by the BIOS to verify
> >> > + signatures when setting the signing key. When written,
> >> > + the bytes should correspond to the KEK certificate
> >> > + (x509 .DER format containing an OU). The size of the
> >> > + certificate must be less than or equal to 4095 bytes.
> >> > +
> >> > +What: /sys/class/firmware-attributes/*/authentication/SPM/sk
> >> > +Date: March 29
> >> > +KernelVersion: 5.18
> >> > +Contact: "Jorge Lopez" <[email protected]>
> >> > +Description:
> >> > + 'sk' Signature Key is a write-only file that can be used to
> >> > configure the RSA
> >> > + public key that will be used by the BIOS to verify signatures
> >> > + when configuring BIOS settings and security features. When
> >> > + written, the bytes should correspond to the modulus of the
> >> > + public key. The exponent is assumed to be 0x10001.
> >> > +
> >> > +What: /sys/class/firmware-attributes/*/authentication/SPM/status
> >> > +Date: March 29
> >> > +KernelVersion: 5.18
> >> > +Contact: "Jorge Lopez" <[email protected]>
> >> > +Description:
> >> > + 'status' is a read-only file that returns ASCII text in JSON format
> >> > reporting
> >> > + the status information.
> >> > +
> >> > + "State": "not provisioned | provisioned | provisioning in progress
> >> > ",
> >> > + "Version": " Major. Minor ",
> >> > + "Nonce": <16-bit unsigned number display in base 10>,
> >> > + "FeaturesInUse": <16-bit unsigned number display in base 10>,
> >> > + "EndorsementKeyMod": "<256 bytes in base64>",
> >> > + "SigningKeyMod": "<256 bytes in base64>"
> >> > +
> >> > +What: /sys/class/firmware-attributes/*/attributes/Sure_Start/audit_log_entries
> >> > +Date: March 29
> >> > +KernelVersion: 5.18
> >> > +Contact: "Jorge Lopez" <[email protected]>
> >> > +Description:
> >> > + 'audit_log_entries' is a read-only file that returns the events in
> >> > the log.
> >> > +
> >> > + Audit log entry format
> >> > +
> >> > + Byte 0-15: Requested Audit Log entry (Each Audit log is 16 bytes)
> >> > + Byte 16-127: Unused
> >> > +
> >> > +What: /sys/class/firmware-attributes/*/attributes/Sure_Start/audit_log_entry_count
> >> > +Date: March 29
> >> > +KernelVersion: 5.18
> >> > +Contact: "Jorge Lopez" <[email protected]>
> >> > +Description:
> >> > + 'audit_log_entry_count' is a read-only file that returns the number
> >> > of existing
> >> > + audit log events available to be read. Values are separated using
> >> > comma (``,``)
> >> > +
> >> > + [No of entries],[log entry size],[Max number of entries supported]
> >> > +
> >> > + log entry size identifies audit log size for the current BIOS
> >> > version.
> >> > + The current size is 16 bytes but it can be up to 128 bytes long in
> >> > future BIOS
> >> > + versions.
> >> > --
> >> > 2.34.1
> >>
> >> Firstly apologies as I've done a poor job of following the updates to this series - so if this has already been discussed and agreed by more seasoned kernel contributors please feel free to disregard my comments :) I was catching up on my inbox and had some thoughts.
> >
> > No worries.
> >
> >>
> >> For SPM - as this replaces password usage, is it done for all account types? It seems a bit odd having it be a replacement for the passwords but in it's own location and not in the same place as (for example) Admin/current_password.
> >> For the Lenovo implementation I put certificate, signature and save_signature in the authentication/Admin directory and I realise your implementation is different with the keys but if the kek and sk are only used with the Admin account then shouldn't they also be in that directory? It would be nice to have some commonality across vendors in my opinion.
> >>
> >
> > SPM (Security Platform Management) does not replace password usage and
> > it is done for the Admin account (Setup Password). SPM is a security
> > feature available to the user to configure/update BIOS settings when
> > Sure Admin is enabled in BIOS. One of the files provided under SPM is
> > the key _role and its value is set to ‘bios-spm.’ A ‘bios-spm’ role
> > indicates a password is used in combination with an
> > endorsement/signing key. It is also the reason why SPM is kept
> > separate under the list of authentication attributes.
>
> Ah - I think I get it, and in that case I can see why you keep it separate and it is a unique role.
> I withdraw my suggestion :)
>
> >
> >> For the Sure_Start I would propose de-branding this so it's generic and I don't think it fits under attributes as it doesn't support any of the other required attribute fields. I think your implementation of an audit log seems neat but if another vendor was to do similar it would be better to be able to reuse the same attribute name and enable common tooling.
> >> I propose having this as just log/audit_entries and log/audit_count and have the log folder in the top alongside authentication and attributes.
> >> If someone wants to add other logs in the future it would be a good place to have them.
> >
> > I like the idea of having a log folder alongside authentication and
> > attributes where future logs can be placed. Unfortunately, Sure_Start
> > is part of the security attributes and the initial driver provides a
> > minimal implementation. Other attributes associated with Sure_Start
> > and available in BIOS are 'SureStart Production Mode', 'Sure Start
> > Security Event Boot Notification', 'Sure Start BIOS Settings
> > Protection', 'Sure Start Secure Boot Keys Protection', and 'Sure Start
> > Security Event Policy'
>
> Aren't all of these just regular attributes that show up under the attributes folder (and have current_value and possible_value settings etc)? Do they get created in your equivalent of probing the BIOS to determine what attributes are available or are they manually created entries? (I'm assuming automatic or they would be also added to the documentation)

'SureStart Production Mode', 'Sure Start Security Event Boot
Notification', 'Sure Start BIOS Settings Protection', 'Sure Start
Secure Boot Keys Protection', and 'Sure Start Security Event Policy'
are reported by BIOS therefore listed under attributes. 'Sure
Start/audit_log_entries and Sure_Start/audit_log_count_entries are
created manually and kept under attributes/Sure_Start; same location
as all other 'Sure Start' entries.

>
> It seemed to me the audit log entries were being handled differently because you had to specifically create the entries, with (I assume) some special handling for display?

Gathering the number of entries and reading each audit logs require
making multiple WMI calls (Security related). If 'Sure Start' was not
part of a security feature, I would agree to move it under a log
directory; sadly it is not the case.
>
> Mark

2023-05-23 16:24:10

by Mark Pearson

[permalink] [raw]
Subject: Re: [PATCH v14 01/13] hp-bioscfg: Documentation

Thanks Jorge

On Tue, May 23, 2023, at 10:16 AM, Jorge Lopez wrote:
> On Fri, May 19, 2023 at 6:19 PM Mark Pearson <[email protected]> wrote:
>>
>> Thanks Jorge,
>>
>> On Fri, May 19, 2023, at 4:58 PM, Jorge Lopez wrote:
>> > On Fri, May 19, 2023 at 12:34 PM Mark Pearson <[email protected]> wrote:
>> >>
>> >> Hi Jorge,
>> >>
>> >> On Wed, May 17, 2023, at 11:50 AM, Jorge Lopez wrote:
>> >> > HP BIOS Configuration driver purpose is to provide a driver supporting
>> >> > the latest sysfs class firmware attributes framework allowing the user
>> >> > to change BIOS settings and security solutions on HP Inc.’s commercial
>> >> > notebooks.
>> >> >
>> >> > Many features of HP Commercial notebooks can be managed using Windows
>> >> > Management Instrumentation (WMI). WMI is an implementation of Web-Based
>> >> > Enterprise Management (WBEM) that provides a standards-based interface
>> >> > for changing and monitoring system settings. HP BIOSCFG driver provides
>> >> > a native Linux solution and the exposed features facilitates the
>> >> > migration to Linux environments.
>> >> >
>> >> > The Linux security features to be provided in hp-bioscfg driver enables
>> >> > managing the BIOS settings and security solutions via sysfs, a virtual
>> >> > filesystem that can be used by user-mode applications. The new
>> >> > documentation cover HP-specific firmware sysfs attributes such Secure
>> >> > Platform Management and Sure Start. Each section provides security
>> >> > feature description and identifies sysfs directories and files exposed
>> >> > by the driver.
>> >> >
>> >> > Many HP Commercial notebooks include a feature called Secure Platform
>> >> > Management (SPM), which replaces older password-based BIOS settings
>> >> > management with public key cryptography. PC secure product management
>> >> > begins when a target system is provisioned with cryptographic keys
>> >> > that are used to ensure the integrity of communications between system
>> >> > management utilities and the BIOS.
>> >> >
>> >> > HP Commercial notebooks have several BIOS settings that control its
>> >> > behaviour and capabilities, many of which are related to security.
>> >> > To prevent unauthorized changes to these settings, the system can
>> >> > be configured to use a cryptographic signature-based authorization
>> >> > string that the BIOS will use to verify authorization to modify the
>> >> > setting.
>> >> >
>> >> > Linux Security components are under development and not published yet.
>> >> > The only linux component is the driver (hp bioscfg) at this time.
>> >> > Other published security components are under Windows.
>> >> >
>> >> > Signed-off-by: Jorge Lopez <[email protected]>
>> >> >
>> >> > ---
>> >> > Based on the latest platform-drivers-x86.git/for-next
>> >> > ---
>> >> > .../testing/sysfs-class-firmware-attributes | 102 +++++++++++++++++-
>> >> > 1 file changed, 100 insertions(+), 2 deletions(-)
>> >> >
>> >> > diff --git a/Documentation/ABI/testing/sysfs-class-firmware-attributes
>> >> > b/Documentation/ABI/testing/sysfs-class-firmware-attributes
>> >> > index 4cdba3477176..f8d6c089228b 100644
>> >> > --- a/Documentation/ABI/testing/sysfs-class-firmware-attributes
>> >> > +++ b/Documentation/ABI/testing/sysfs-class-firmware-attributes
>> >> <snip>
>> >> > +
>> >> > +
>> >> > + HP specific class extensions - Secure Platform Manager (SPM)
>> >> > + --------------------------------
>> >> > +
>> >> > +What: /sys/class/firmware-attributes/*/authentication/SPM/kek
>> >> > +Date: March 29
>> >> > +KernelVersion: 5.18
>> >> > +Contact: "Jorge Lopez" <[email protected]>
>> >> > +Description:
>> >> > + 'kek' Key-Encryption-Key is a write-only file that can be used to
>> >> > configure the
>> >> > + RSA public key that will be used by the BIOS to verify
>> >> > + signatures when setting the signing key. When written,
>> >> > + the bytes should correspond to the KEK certificate
>> >> > + (x509 .DER format containing an OU). The size of the
>> >> > + certificate must be less than or equal to 4095 bytes.
>> >> > +
>> >> > +What: /sys/class/firmware-attributes/*/authentication/SPM/sk
>> >> > +Date: March 29
>> >> > +KernelVersion: 5.18
>> >> > +Contact: "Jorge Lopez" <[email protected]>
>> >> > +Description:
>> >> > + 'sk' Signature Key is a write-only file that can be used to
>> >> > configure the RSA
>> >> > + public key that will be used by the BIOS to verify signatures
>> >> > + when configuring BIOS settings and security features. When
>> >> > + written, the bytes should correspond to the modulus of the
>> >> > + public key. The exponent is assumed to be 0x10001.
>> >> > +
>> >> > +What: /sys/class/firmware-attributes/*/authentication/SPM/status
>> >> > +Date: March 29
>> >> > +KernelVersion: 5.18
>> >> > +Contact: "Jorge Lopez" <[email protected]>
>> >> > +Description:
>> >> > + 'status' is a read-only file that returns ASCII text in JSON format
>> >> > reporting
>> >> > + the status information.
>> >> > +
>> >> > + "State": "not provisioned | provisioned | provisioning in progress
>> >> > ",
>> >> > + "Version": " Major. Minor ",
>> >> > + "Nonce": <16-bit unsigned number display in base 10>,
>> >> > + "FeaturesInUse": <16-bit unsigned number display in base 10>,
>> >> > + "EndorsementKeyMod": "<256 bytes in base64>",
>> >> > + "SigningKeyMod": "<256 bytes in base64>"
>> >> > +
>> >> > +What: /sys/class/firmware-attributes/*/attributes/Sure_Start/audit_log_entries
>> >> > +Date: March 29
>> >> > +KernelVersion: 5.18
>> >> > +Contact: "Jorge Lopez" <[email protected]>
>> >> > +Description:
>> >> > + 'audit_log_entries' is a read-only file that returns the events in
>> >> > the log.
>> >> > +
>> >> > + Audit log entry format
>> >> > +
>> >> > + Byte 0-15: Requested Audit Log entry (Each Audit log is 16 bytes)
>> >> > + Byte 16-127: Unused
>> >> > +
>> >> > +What: /sys/class/firmware-attributes/*/attributes/Sure_Start/audit_log_entry_count
>> >> > +Date: March 29
>> >> > +KernelVersion: 5.18
>> >> > +Contact: "Jorge Lopez" <[email protected]>
>> >> > +Description:
>> >> > + 'audit_log_entry_count' is a read-only file that returns the number
>> >> > of existing
>> >> > + audit log events available to be read. Values are separated using
>> >> > comma (``,``)
>> >> > +
>> >> > + [No of entries],[log entry size],[Max number of entries supported]
>> >> > +
>> >> > + log entry size identifies audit log size for the current BIOS
>> >> > version.
>> >> > + The current size is 16 bytes but it can be up to 128 bytes long in
>> >> > future BIOS
>> >> > + versions.
>> >> > --
>> >> > 2.34.1
>> >>
>> >> Firstly apologies as I've done a poor job of following the updates to this series - so if this has already been discussed and agreed by more seasoned kernel contributors please feel free to disregard my comments :) I was catching up on my inbox and had some thoughts.
>> >
>> > No worries.
>> >
>> >>
>> >> For SPM - as this replaces password usage, is it done for all account types? It seems a bit odd having it be a replacement for the passwords but in it's own location and not in the same place as (for example) Admin/current_password.
>> >> For the Lenovo implementation I put certificate, signature and save_signature in the authentication/Admin directory and I realise your implementation is different with the keys but if the kek and sk are only used with the Admin account then shouldn't they also be in that directory? It would be nice to have some commonality across vendors in my opinion.
>> >>
>> >
>> > SPM (Security Platform Management) does not replace password usage and
>> > it is done for the Admin account (Setup Password). SPM is a security
>> > feature available to the user to configure/update BIOS settings when
>> > Sure Admin is enabled in BIOS. One of the files provided under SPM is
>> > the key _role and its value is set to ‘bios-spm.’ A ‘bios-spm’ role
>> > indicates a password is used in combination with an
>> > endorsement/signing key. It is also the reason why SPM is kept
>> > separate under the list of authentication attributes.
>>
>> Ah - I think I get it, and in that case I can see why you keep it separate and it is a unique role.
>> I withdraw my suggestion :)
>>
>> >
>> >> For the Sure_Start I would propose de-branding this so it's generic and I don't think it fits under attributes as it doesn't support any of the other required attribute fields. I think your implementation of an audit log seems neat but if another vendor was to do similar it would be better to be able to reuse the same attribute name and enable common tooling.
>> >> I propose having this as just log/audit_entries and log/audit_count and have the log folder in the top alongside authentication and attributes.
>> >> If someone wants to add other logs in the future it would be a good place to have them.
>> >
>> > I like the idea of having a log folder alongside authentication and
>> > attributes where future logs can be placed. Unfortunately, Sure_Start
>> > is part of the security attributes and the initial driver provides a
>> > minimal implementation. Other attributes associated with Sure_Start
>> > and available in BIOS are 'SureStart Production Mode', 'Sure Start
>> > Security Event Boot Notification', 'Sure Start BIOS Settings
>> > Protection', 'Sure Start Secure Boot Keys Protection', and 'Sure Start
>> > Security Event Policy'
>>
>> Aren't all of these just regular attributes that show up under the attributes folder (and have current_value and possible_value settings etc)? Do they get created in your equivalent of probing the BIOS to determine what attributes are available or are they manually created entries? (I'm assuming automatic or they would be also added to the documentation)
>
> 'SureStart Production Mode', 'Sure Start Security Event Boot
> Notification', 'Sure Start BIOS Settings Protection', 'Sure Start
> Secure Boot Keys Protection', and 'Sure Start Security Event Policy'
> are reported by BIOS therefore listed under attributes. 'Sure
> Start/audit_log_entries and Sure_Start/audit_log_count_entries are
> created manually and kept under attributes/Sure_Start; same location
> as all other 'Sure Start' entries.
>
Thanks for the clarification

>>
>> It seemed to me the audit log entries were being handled differently because you had to specifically create the entries, with (I assume) some special handling for display?
>
> Gathering the number of entries and reading each audit logs require
> making multiple WMI calls (Security related). If 'Sure Start' was not
> part of a security feature, I would agree to move it under a log
> directory; sadly it is not the case.

OK - I'll defer to the more experienced kernel folk; but to me I think the argument still stands that these two fields are not standard attributes (they won't have any of the regular attribute fields) and by being in a directory they look as if they are trying to be. My vote would still be to:

- make them non vendor trademark specific so it could be used by other vendors for similar in the future.
- move them out of the attributes folder as they seem a bad fit to me

Thanks for all the insights - appreciated :)
Mark