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From:   Nayna Jain <nayna@linux.ibm.com>
To:     linux-integrity@vger.kernel.org
Cc:     Mimi Zohar <zohar@linux.ibm.com>,
        Jarkko Sakkinen <jarkko@kernel.org>,
        Eric Snowberg <eric.snowberg@oracle.com>,
        Paul Moore <paul@paul-moore.com>,
        linuxppc-dev <linuxppc-dev@lists.ozlabs.org>,
        linux-security-module@vger.kernel.org,
        linux-kernel@vger.kernel.org, Nayna Jain <nayna@linux.ibm.com>
Subject: [PATCH 1/6] integrity: PowerVM support for loading CA keys on machine keyring
Date:   Fri, 14 Jul 2023 11:34:30 -0400
Message-Id: <20230714153435.28155-2-nayna@linux.ibm.com>
In-Reply-To: <20230714153435.28155-1-nayna@linux.ibm.com>
References: <20230714153435.28155-1-nayna@linux.ibm.com>
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Keys that derive their trust from an entity such as a security officer,
administrator, system owner, or machine owner are said to have "imputed
trust". CA keys with imputed trust can be loaded onto the machine keyring.
The mechanism for loading these keys onto the machine keyring is platform
dependent.

Load keys stored in the variable trustedcadb onto the .machine keyring
on PowerVM platform.

Signed-off-by: Nayna Jain <nayna@linux.ibm.com>
---
 .../integrity/platform_certs/keyring_handler.c  |  8 ++++++++
 .../integrity/platform_certs/keyring_handler.h  |  5 +++++
 .../integrity/platform_certs/load_powerpc.c     | 17 +++++++++++++++++
 3 files changed, 30 insertions(+)

diff --git a/security/integrity/platform_certs/keyring_handler.c b/security/integrity/platform_certs/keyring_handler.c
index 8a1124e4d769..1649d047e3b8 100644
--- a/security/integrity/platform_certs/keyring_handler.c
+++ b/security/integrity/platform_certs/keyring_handler.c
@@ -69,6 +69,14 @@ __init efi_element_handler_t get_handler_for_mok(const efi_guid_t *sig_type)
 	return NULL;
 }
 
+__init efi_element_handler_t get_handler_for_ca_keys(const efi_guid_t *sig_type)
+{
+	if (efi_guidcmp(*sig_type, efi_cert_x509_guid) == 0)
+		return add_to_machine_keyring;
+
+	return NULL;
+}
+
 /*
  * Return the appropriate handler for particular signature list types found in
  * the UEFI dbx and MokListXRT tables.
diff --git a/security/integrity/platform_certs/keyring_handler.h b/security/integrity/platform_certs/keyring_handler.h
index 212d894a8c0c..6f15bb4cc8dc 100644
--- a/security/integrity/platform_certs/keyring_handler.h
+++ b/security/integrity/platform_certs/keyring_handler.h
@@ -29,6 +29,11 @@ efi_element_handler_t get_handler_for_db(const efi_guid_t *sig_type);
  */
 efi_element_handler_t get_handler_for_mok(const efi_guid_t *sig_type);
 
+/*
+ * Return the handler for particular signature list types for CA keys.
+ */
+efi_element_handler_t get_handler_for_ca_keys(const efi_guid_t *sig_type);
+
 /*
  * Return the handler for particular signature list types found in the dbx.
  */
diff --git a/security/integrity/platform_certs/load_powerpc.c b/security/integrity/platform_certs/load_powerpc.c
index 170789dc63d2..6263ce3b3f1e 100644
--- a/security/integrity/platform_certs/load_powerpc.c
+++ b/security/integrity/platform_certs/load_powerpc.c
@@ -59,6 +59,7 @@ static __init void *get_cert_list(u8 *key, unsigned long keylen, u64 *size)
 static int __init load_powerpc_certs(void)
 {
 	void *db = NULL, *dbx = NULL, *data = NULL;
+	void *trustedca = NULL;
 	u64 dsize = 0;
 	u64 offset = 0;
 	int rc = 0;
@@ -120,6 +121,22 @@ static int __init load_powerpc_certs(void)
 		kfree(data);
 	}
 
+	data = get_cert_list("trustedcadb", 12,  &dsize);
+	if (!data) {
+		pr_info("Couldn't get trustedcadb list from firmware\n");
+	} else if (IS_ERR(data)) {
+		rc = PTR_ERR(data);
+		pr_err("Error reading trustedcadb from firmware: %d\n", rc);
+	} else {
+		extract_esl(trustedca, data, dsize, offset);
+
+		rc = parse_efi_signature_list("powerpc:trustedca", trustedca, dsize,
+					      get_handler_for_ca_keys);
+		if (rc)
+			pr_err("Couldn't parse trustedcadb signatures: %d\n", rc);
+		kfree(data);
+	}
+
 	return rc;
 }
 late_initcall(load_powerpc_certs);
-- 
2.31.1