First four patches are a resend algif_akcipher from
Stephan Mueller, with minor changes after rebase on top of 4.7-rc1.
The next three patches add support for keys stored in system
keyring subsystem.
First patch adds algif_akcipher nokey hadlers.
Second patch adds generic sign, verify, encrypt, decrypt accessors
functions to the asymmetric key type. These will be defined by
asymmetric subtypes, similarly to how public_key currently defines
the verify_signature function.
Third patch adds support for ALG_SET_KEY_ID and ALG_SET_PUBKEY_ID
commands to AF_ALG and setkeyid operation to the af_alg_type struct.
If the keyid is used then the afalg layer acquires the key for the
keyring subsystem and uses the new asymmetric accessor functions
instead of akcipher api. The asymmetric subtypes can use akcipher
api internally.
Patches are generate against:
http://git.kernel.org/cgit/linux/kernel/git/dhowells/linux-fs.git/log/?h=keys-next
v8 hanges:
- copy the result to user for verify after the signature_verify
operation. Before only the return code was checked, but not the
actual data. Reported by Mat Martineau
- remove the constrain on the output buffer size as requested by
Mat Martineau
- ifx uninitialize variable issue, reported by Mat Martineau
v7 changes:
- update to reflect changes in kernel_pkey_params struct
v6 changes:
- rabased on top of
http://git.kernel.org/cgit/linux/kernel/git/dhowells/linux-fs.git/log/?h=keys-asym-keyctl
v5 changes:
- drop public key changes and use new version provided by David
v4 changes:
- don't use internal public_key struct in af_alg.
- add generic accessor functions to asymmetric key type, which take
the generic struct key type and resolve the specific subtype internally
v3 changes:
- include Stephan's patches (rebased on 4.6-rc1)
- add algif_akcipher nokey hadlers
- add public_key info struct to public_key and helper query functions
- add a check if a key is a software accessible key on af_alg, and
return -ENOKEY if it isn't
v2 changes:
- pass the original skcipher request in ablkcipher.base.data instead of
casting it back from the ablkcipher request.
- rename _req to base_req
- dropped 3/3
---
Stephan Mueller (4):
crypto: AF_ALG -- add sign/verify API
crypto: AF_ALG -- add setpubkey setsockopt call
crypto: AF_ALG -- add asymmetric cipher interface
crypto: algif_akcipher - enable compilation
Tadeusz Struk (2):
crypto: algif_akcipher - add ops_nokey
crypto: AF_ALG - add support for key_id
crypto/Kconfig | 9
crypto/Makefile | 1
crypto/af_alg.c | 28 +
crypto/algif_akcipher.c | 878 +++++++++++++++++++++++++++++++++++++++++++
include/crypto/if_alg.h | 2
include/uapi/linux/if_alg.h | 5
6 files changed, 918 insertions(+), 5 deletions(-)
create mode 100644 crypto/algif_akcipher.c
--
TS
From: Stephan Mueller <[email protected]>
Add the Makefile and Kconfig updates to allow algif_akcipher to be
compiled.
Signed-off-by: Stephan Mueller <[email protected]>
Signed-off-by: Tadeusz Struk <[email protected]>
---
crypto/Kconfig | 9 +++++++++
crypto/Makefile | 1 +
2 files changed, 10 insertions(+)
diff --git a/crypto/Kconfig b/crypto/Kconfig
index 1d33beb..3c6113e 100644
--- a/crypto/Kconfig
+++ b/crypto/Kconfig
@@ -1627,6 +1627,15 @@ config CRYPTO_USER_API_AEAD
This option enables the user-spaces interface for AEAD
cipher algorithms.
+config CRYPTO_USER_API_AKCIPHER
+ tristate "User-space interface for asymmetric key cipher algorithms"
+ depends on NET
+ select CRYPTO_AKCIPHER2
+ select CRYPTO_USER_API
+ help
+ This option enables the user-spaces interface for asymmetric
+ key cipher algorithms.
+
config CRYPTO_HASH_INFO
bool
diff --git a/crypto/Makefile b/crypto/Makefile
index 4f4ef7e..c51ac16 100644
--- a/crypto/Makefile
+++ b/crypto/Makefile
@@ -121,6 +121,7 @@ obj-$(CONFIG_CRYPTO_USER_API_HASH) += algif_hash.o
obj-$(CONFIG_CRYPTO_USER_API_SKCIPHER) += algif_skcipher.o
obj-$(CONFIG_CRYPTO_USER_API_RNG) += algif_rng.o
obj-$(CONFIG_CRYPTO_USER_API_AEAD) += algif_aead.o
+obj-$(CONFIG_CRYPTO_USER_API_AKCIPHER) += algif_akcipher.o
#
# generic algorithms and the async_tx api
This patch adds support for asymmetric key type to AF_ALG.
It will work as follows: A new PF_ALG socket options are
added on top of existing ALG_SET_KEY and ALG_SET_PUBKEY, namely
ALG_SET_KEY_ID and ALG_SET_PUBKEY_ID for setting public and
private keys respectively. When these new options will be used
the user, instead of providing the key material, will provide a
key id and the key itself will be obtained from kernel keyring
subsystem. The user will use the standard tools (keyctl tool
or the keyctl syscall) for key instantiation and to obtain the
key id. The key id can also be obtained by reading the
/proc/keys file.
When a key corresponding to the given keyid is found, it is stored
in the socket context and subsequent crypto operation invoked by the
user will use the new asymmetric accessor functions instead of akcipher
api. The asymmetric subtype can internally use akcipher api or
invoke operations defined by a given subtype, depending on the
key type.
Signed-off-by: Tadeusz Struk <[email protected]>
---
crypto/af_alg.c | 10 ++
crypto/algif_akcipher.c | 212 ++++++++++++++++++++++++++++++++++++++++++-
include/crypto/if_alg.h | 1
include/uapi/linux/if_alg.h | 2
4 files changed, 220 insertions(+), 5 deletions(-)
diff --git a/crypto/af_alg.c b/crypto/af_alg.c
index 24dc082..59c8244 100644
--- a/crypto/af_alg.c
+++ b/crypto/af_alg.c
@@ -260,6 +260,16 @@ static int alg_setsockopt(struct socket *sock, int level, int optname,
err = alg_setkey(sk, optval, optlen, type->setpubkey);
break;
+
+ case ALG_SET_KEY_ID:
+ case ALG_SET_PUBKEY_ID:
+ /* ALG_SET_KEY_ID is only for akcipher */
+ if (!strcmp(type->name, "akcipher") ||
+ sock->state == SS_CONNECTED)
+ goto unlock;
+
+ err = alg_setkey(sk, optval, optlen, type->setkeyid);
+ break;
case ALG_SET_AEAD_AUTHSIZE:
if (sock->state == SS_CONNECTED)
goto unlock;
diff --git a/crypto/algif_akcipher.c b/crypto/algif_akcipher.c
index 2b8d37e..106f715 100644
--- a/crypto/algif_akcipher.c
+++ b/crypto/algif_akcipher.c
@@ -14,6 +14,8 @@
#include <crypto/akcipher.h>
#include <crypto/scatterwalk.h>
#include <crypto/if_alg.h>
+#include <crypto/public_key.h>
+#include <keys/asymmetric-type.h>
#include <linux/init.h>
#include <linux/list.h>
#include <linux/kernel.h>
@@ -29,6 +31,7 @@ struct akcipher_sg_list {
struct akcipher_tfm {
struct crypto_akcipher *akcipher;
+ char keyid[12];
bool has_key;
};
@@ -37,6 +40,7 @@ struct akcipher_ctx {
struct af_alg_sgl rsgl[ALG_MAX_PAGES];
struct af_alg_completion completion;
+ struct key *key;
unsigned long used;
@@ -317,6 +321,158 @@ unlock:
return err ? err : size;
}
+static int asym_key_encrypt(const struct key *key, struct akcipher_request *req)
+{
+ struct kernel_pkey_params params = {0};
+ char *src = NULL, *dst = NULL, *in, *out;
+ int ret;
+
+ if (!sg_is_last(req->src)) {
+ src = kmalloc(req->src_len, GFP_KERNEL);
+ if (!src)
+ return -ENOMEM;
+ scatterwalk_map_and_copy(src, req->src, 0, req->src_len, 0);
+ in = src;
+ } else {
+ in = sg_virt(req->src);
+ }
+ if (!sg_is_last(req->dst)) {
+ dst = kmalloc(req->dst_len, GFP_KERNEL);
+ if (!dst) {
+ kfree(src);
+ return -ENOMEM;
+ }
+ out = dst;
+ } else {
+ out = sg_virt(req->dst);
+ }
+ params.key = (struct key *)key;
+ params.in_len = req->src_len;
+ params.out_len = req->dst_len;
+ ret = encrypt_blob(¶ms, in, out);
+ if (ret)
+ goto free;
+
+ if (dst)
+ scatterwalk_map_and_copy(dst, req->dst, 0, req->dst_len, 1);
+free:
+ kfree(src);
+ kfree(dst);
+ return ret;
+}
+
+static int asym_key_decrypt(const struct key *key, struct akcipher_request *req)
+{
+ struct kernel_pkey_params params = {0};
+ char *src = NULL, *dst = NULL, *in, *out;
+ int ret;
+
+ if (!sg_is_last(req->src)) {
+ src = kmalloc(req->src_len, GFP_KERNEL);
+ if (!src)
+ return -ENOMEM;
+ scatterwalk_map_and_copy(src, req->src, 0, req->src_len, 0);
+ in = src;
+ } else {
+ in = sg_virt(req->src);
+ }
+ if (!sg_is_last(req->dst)) {
+ dst = kmalloc(req->dst_len, GFP_KERNEL);
+ if (!dst) {
+ kfree(src);
+ return -ENOMEM;
+ }
+ out = dst;
+ } else {
+ out = sg_virt(req->dst);
+ }
+ params.key = (struct key *)key;
+ params.in_len = req->src_len;
+ params.out_len = req->dst_len;
+ ret = decrypt_blob(¶ms, in, out);
+ if (ret)
+ goto free;
+
+ if (dst)
+ scatterwalk_map_and_copy(dst, req->dst, 0, req->dst_len, 1);
+free:
+ kfree(src);
+ kfree(dst);
+ return ret;
+}
+
+static int asym_key_sign(const struct key *key, struct akcipher_request *req)
+{
+ struct kernel_pkey_params params = {0};
+ char *src = NULL, *dst = NULL, *in, *out;
+ int ret;
+
+ if (!sg_is_last(req->src)) {
+ src = kmalloc(req->src_len, GFP_KERNEL);
+ if (!src)
+ return -ENOMEM;
+ scatterwalk_map_and_copy(src, req->src, 0, req->src_len, 0);
+ in = src;
+ } else {
+ in = sg_virt(req->src);
+ }
+ if (!sg_is_last(req->dst)) {
+ dst = kmalloc(req->dst_len, GFP_KERNEL);
+ if (!dst) {
+ kfree(src);
+ return -ENOMEM;
+ }
+ out = dst;
+ } else {
+ out = sg_virt(req->dst);
+ }
+ params.key = (struct key *)key;
+ params.in_len = req->src_len;
+ params.out_len = req->dst_len;
+ ret = create_signature(¶ms, in, out);
+ if (ret)
+ goto free;
+
+ if (dst)
+ scatterwalk_map_and_copy(dst, req->dst, 0, req->dst_len, 1);
+free:
+ kfree(src);
+ kfree(dst);
+ return ret;
+}
+
+static int asym_key_verify(const struct key *key, struct akcipher_request *req)
+{
+ struct public_key_signature sig;
+ char *src = NULL, *in, digest[20];
+ int ret;
+
+ if (!sg_is_last(req->src)) {
+ src = kmalloc(req->src_len, GFP_KERNEL);
+ if (!src)
+ return -ENOMEM;
+ scatterwalk_map_and_copy(src, req->src, 0, req->src_len, 0);
+ in = src;
+ } else {
+ in = sg_virt(req->src);
+ }
+ sig.pkey_algo = "rsa";
+ sig.encoding = "pkcs1";
+ /* Need to find a way to pass the hash param */
+ sig.hash_algo = "sha1";
+ sig.digest_size = sizeof(digest);
+ sig.digest = digest;
+ sig.s_size = req->src_len;
+ sig.s = src;
+ ret = verify_signature(key, &sig);
+ if (!ret) {
+ req->dst_len = sizeof(digest);
+ scatterwalk_map_and_copy(digest, req->dst, 0, req->dst_len, 1);
+ }
+ kfree(src);
+ return ret;
+}
+
static int akcipher_recvmsg(struct socket *sock, struct msghdr *msg,
size_t ignored, int flags)
{
@@ -366,16 +522,28 @@ static int akcipher_recvmsg(struct socket *sock, struct msghdr *msg,
usedpages);
switch (ctx->op) {
case ALG_OP_VERIFY:
- err = crypto_akcipher_verify(&ctx->req);
+ if (ctx->key)
+ err = asym_key_verify(ctx->key, &ctx->req);
+ else
+ err = crypto_akcipher_verify(&ctx->req);
break;
case ALG_OP_SIGN:
- err = crypto_akcipher_sign(&ctx->req);
+ if (ctx->key)
+ err = asym_key_sign(ctx->key, &ctx->req);
+ else
+ err = crypto_akcipher_sign(&ctx->req);
break;
case ALG_OP_ENCRYPT:
- err = crypto_akcipher_encrypt(&ctx->req);
+ if (ctx->key)
+ err = asym_key_encrypt(ctx->key, &ctx->req);
+ else
+ err = crypto_akcipher_encrypt(&ctx->req);
break;
case ALG_OP_DECRYPT:
- err = crypto_akcipher_decrypt(&ctx->req);
+ if (ctx->key)
+ err = asym_key_decrypt(ctx->key, &ctx->req);
+ else
+ err = crypto_akcipher_decrypt(&ctx->req);
break;
default:
err = -EFAULT;
@@ -568,6 +736,27 @@ static void akcipher_release(void *private)
kfree(tfm);
}
+static int akcipher_setkeyid(void *private, const u8 *key, unsigned int keylen)
+{
+ struct akcipher_tfm *tfm = private;
+ struct key *akey;
+ u32 keyid = *((u32 *)key);
+ int err = -ENOKEY;
+
+ /* Store the key id and verify that a key with the given id is present.
+ * The actual key will be acquired in the accept_parent function
+ */
+ sprintf(tfm->keyid, "id:%08x", keyid);
+ akey = request_key(&key_type_asymmetric, tfm->keyid, NULL);
+ if (IS_ERR(key))
+ goto out;
+
+ tfm->has_key = true;
+ key_put(akey);
+out:
+ return err;
+}
+
static int akcipher_setprivkey(void *private, const u8 *key,
unsigned int keylen)
{
@@ -599,6 +788,8 @@ static void akcipher_sock_destruct(struct sock *sk)
akcipher_put_sgl(sk);
sock_kfree_s(sk, ctx, ctx->len);
af_alg_release_parent(sk);
+ if (ctx->key)
+ key_put(ctx->key);
}
static int akcipher_accept_parent_nokey(void *private, struct sock *sk)
@@ -607,6 +798,7 @@ static int akcipher_accept_parent_nokey(void *private, struct sock *sk)
struct alg_sock *ask = alg_sk(sk);
struct akcipher_tfm *tfm = private;
struct crypto_akcipher *akcipher = tfm->akcipher;
+ struct key *key;
unsigned int len = sizeof(*ctx) + crypto_akcipher_reqsize(akcipher);
ctx = sock_kmalloc(sk, len, GFP_KERNEL);
@@ -623,11 +815,20 @@ static int akcipher_accept_parent_nokey(void *private, struct sock *sk)
af_alg_init_completion(&ctx->completion);
sg_init_table(ctx->tsgl.sg, ALG_MAX_PAGES);
- ask->private = ctx;
+ if (strlen(tfm->keyid)) {
+ key = request_key(&key_type_asymmetric, tfm->keyid, NULL);
+ if (IS_ERR(key)) {
+ sock_kfree_s(sk, ctx, len);
+ return -ENOKEY;
+ }
+ ctx->key = key;
+ memset(tfm->keyid, '\0', sizeof(tfm->keyid));
+ }
akcipher_request_set_tfm(&ctx->req, akcipher);
akcipher_request_set_callback(&ctx->req, CRYPTO_TFM_REQ_MAY_BACKLOG,
af_alg_complete, &ctx->completion);
+ ask->private = ctx;
sk->sk_destruct = akcipher_sock_destruct;
@@ -649,6 +850,7 @@ static const struct af_alg_type algif_type_akcipher = {
.release = akcipher_release,
.setkey = akcipher_setprivkey,
.setpubkey = akcipher_setpubkey,
+ .setkeyid = akcipher_setkeyid,
.accept = akcipher_accept_parent,
.accept_nokey = akcipher_accept_parent_nokey,
.ops = &algif_akcipher_ops,
diff --git a/include/crypto/if_alg.h b/include/crypto/if_alg.h
index 6c3e6e7..09c99ab 100644
--- a/include/crypto/if_alg.h
+++ b/include/crypto/if_alg.h
@@ -53,6 +53,7 @@ struct af_alg_type {
void (*release)(void *private);
int (*setkey)(void *private, const u8 *key, unsigned int keylen);
int (*setpubkey)(void *private, const u8 *key, unsigned int keylen);
+ int (*setkeyid)(void *private, const u8 *key, unsigned int keylen);
int (*accept)(void *private, struct sock *sk);
int (*accept_nokey)(void *private, struct sock *sk);
int (*setauthsize)(void *private, unsigned int authsize);
diff --git a/include/uapi/linux/if_alg.h b/include/uapi/linux/if_alg.h
index 02e6162..0379766 100644
--- a/include/uapi/linux/if_alg.h
+++ b/include/uapi/linux/if_alg.h
@@ -35,6 +35,8 @@ struct af_alg_iv {
#define ALG_SET_AEAD_ASSOCLEN 4
#define ALG_SET_AEAD_AUTHSIZE 5
#define ALG_SET_PUBKEY 6
+#define ALG_SET_PUBKEY_ID 7
+#define ALG_SET_KEY_ID 8
/* Operations */
#define ALG_OP_DECRYPT 0
From: Stephan Mueller <[email protected]>
This patch adds the user space interface for asymmetric ciphers. The
interface allows the use of sendmsg as well as vmsplice to provide data.
This version has been rebased on top of 4.7 and a few chackpatch issues
have been fixed. This version also removes the constrain on the output
buffer size.
Signed-off-by: Stephan Mueller <[email protected]>
Signed-off-by: Tadeusz Struk <[email protected]>
---
crypto/algif_akcipher.c | 531 +++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 531 insertions(+)
create mode 100644 crypto/algif_akcipher.c
diff --git a/crypto/algif_akcipher.c b/crypto/algif_akcipher.c
new file mode 100644
index 0000000..8dd6354
--- /dev/null
+++ b/crypto/algif_akcipher.c
@@ -0,0 +1,531 @@
+/*
+ * algif_akcipher: User-space interface for asymmetric cipher algorithms
+ *
+ * Copyright (C) 2015, Stephan Mueller <[email protected]>
+ *
+ * This file provides the user-space API for asymmetric ciphers.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ */
+
+#include <crypto/akcipher.h>
+#include <crypto/scatterwalk.h>
+#include <crypto/if_alg.h>
+#include <linux/init.h>
+#include <linux/list.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/net.h>
+#include <net/sock.h>
+
+struct akcipher_sg_list {
+ unsigned int cur;
+ struct scatterlist sg[ALG_MAX_PAGES];
+};
+
+struct akcipher_ctx {
+ struct akcipher_sg_list tsgl;
+ struct af_alg_sgl rsgl[ALG_MAX_PAGES];
+
+ struct af_alg_completion completion;
+
+ unsigned long used;
+
+ unsigned int len;
+ bool more;
+ bool merge;
+ int op;
+
+ struct akcipher_request req;
+};
+
+static inline int akcipher_sndbuf(struct sock *sk)
+{
+ struct alg_sock *ask = alg_sk(sk);
+ struct akcipher_ctx *ctx = ask->private;
+
+ return max_t(int, max_t(int, sk->sk_sndbuf & PAGE_MASK, PAGE_SIZE) -
+ ctx->used, 0);
+}
+
+static inline bool akcipher_writable(struct sock *sk)
+{
+ return akcipher_sndbuf(sk) >= PAGE_SIZE;
+}
+
+static void akcipher_put_sgl(struct sock *sk)
+{
+ struct alg_sock *ask = alg_sk(sk);
+ struct akcipher_ctx *ctx = ask->private;
+ struct akcipher_sg_list *sgl = &ctx->tsgl;
+ struct scatterlist *sg = sgl->sg;
+ unsigned int i;
+
+ for (i = 0; i < sgl->cur; i++) {
+ if (!sg_page(sg + i))
+ continue;
+
+ put_page(sg_page(sg + i));
+ sg_assign_page(sg + i, NULL);
+ }
+ sg_init_table(sg, ALG_MAX_PAGES);
+ sgl->cur = 0;
+ ctx->used = 0;
+ ctx->more = 0;
+ ctx->merge = 0;
+}
+
+static void akcipher_wmem_wakeup(struct sock *sk)
+{
+ struct socket_wq *wq;
+
+ if (!akcipher_writable(sk))
+ return;
+
+ rcu_read_lock();
+ wq = rcu_dereference(sk->sk_wq);
+ if (wq_has_sleeper(&wq->wait))
+ wake_up_interruptible_sync_poll(&wq->wait, POLLIN |
+ POLLRDNORM |
+ POLLRDBAND);
+ sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
+ rcu_read_unlock();
+}
+
+static int akcipher_wait_for_data(struct sock *sk, unsigned int flags)
+{
+ struct alg_sock *ask = alg_sk(sk);
+ struct akcipher_ctx *ctx = ask->private;
+ long timeout;
+ DEFINE_WAIT(wait);
+ int err = -ERESTARTSYS;
+
+ if (flags & MSG_DONTWAIT)
+ return -EAGAIN;
+
+ set_bit(SOCKWQ_ASYNC_WAITDATA, &sk->sk_socket->flags);
+
+ for (;;) {
+ if (signal_pending(current))
+ break;
+ prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
+ timeout = MAX_SCHEDULE_TIMEOUT;
+ if (sk_wait_event(sk, &timeout, !ctx->more)) {
+ err = 0;
+ break;
+ }
+ }
+ finish_wait(sk_sleep(sk), &wait);
+
+ clear_bit(SOCKWQ_ASYNC_WAITDATA, &sk->sk_socket->flags);
+
+ return err;
+}
+
+static void akcipher_data_wakeup(struct sock *sk)
+{
+ struct alg_sock *ask = alg_sk(sk);
+ struct akcipher_ctx *ctx = ask->private;
+ struct socket_wq *wq;
+
+ if (ctx->more)
+ return;
+ if (!ctx->used)
+ return;
+
+ rcu_read_lock();
+ wq = rcu_dereference(sk->sk_wq);
+ if (wq_has_sleeper(&wq->wait))
+ wake_up_interruptible_sync_poll(&wq->wait, POLLOUT |
+ POLLRDNORM |
+ POLLRDBAND);
+ sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
+ rcu_read_unlock();
+}
+
+static int akcipher_sendmsg(struct socket *sock, struct msghdr *msg,
+ size_t size)
+{
+ struct sock *sk = sock->sk;
+ struct alg_sock *ask = alg_sk(sk);
+ struct akcipher_ctx *ctx = ask->private;
+ struct akcipher_sg_list *sgl = &ctx->tsgl;
+ struct af_alg_control con = {};
+ long copied = 0;
+ int op = 0;
+ bool init = 0;
+ int err = -EINVAL;
+
+ if (msg->msg_controllen) {
+ err = af_alg_cmsg_send(msg, &con);
+ if (err)
+ return err;
+
+ init = 1;
+ switch (con.op) {
+ case ALG_OP_VERIFY:
+ case ALG_OP_SIGN:
+ case ALG_OP_ENCRYPT:
+ case ALG_OP_DECRYPT:
+ op = con.op;
+ break;
+ default:
+ return -EINVAL;
+ }
+ }
+
+ lock_sock(sk);
+ if (!ctx->more && ctx->used)
+ goto unlock;
+
+ if (init)
+ ctx->op = op;
+
+ while (size) {
+ unsigned long len = size;
+ struct scatterlist *sg = NULL;
+
+ /* use the existing memory in an allocated page */
+ if (ctx->merge) {
+ sg = sgl->sg + sgl->cur - 1;
+ len = min_t(unsigned long, len,
+ PAGE_SIZE - sg->offset - sg->length);
+ err = memcpy_from_msg(page_address(sg_page(sg)) +
+ sg->offset + sg->length,
+ msg, len);
+ if (err)
+ goto unlock;
+
+ sg->length += len;
+ ctx->merge = (sg->offset + sg->length) &
+ (PAGE_SIZE - 1);
+
+ ctx->used += len;
+ copied += len;
+ size -= len;
+ continue;
+ }
+
+ if (!akcipher_writable(sk)) {
+ /* user space sent too much data */
+ akcipher_put_sgl(sk);
+ err = -EMSGSIZE;
+ goto unlock;
+ }
+
+ /* allocate a new page */
+ len = min_t(unsigned long, size, akcipher_sndbuf(sk));
+ while (len) {
+ int plen = 0;
+
+ if (sgl->cur >= ALG_MAX_PAGES) {
+ akcipher_put_sgl(sk);
+ err = -E2BIG;
+ goto unlock;
+ }
+
+ sg = sgl->sg + sgl->cur;
+ plen = min_t(int, len, PAGE_SIZE);
+
+ sg_assign_page(sg, alloc_page(GFP_KERNEL));
+ if (!sg_page(sg)) {
+ err = -ENOMEM;
+ goto unlock;
+ }
+
+ err = memcpy_from_msg(page_address(sg_page(sg)),
+ msg, plen);
+ if (err) {
+ __free_page(sg_page(sg));
+ sg_assign_page(sg, NULL);
+ goto unlock;
+ }
+
+ sg->offset = 0;
+ sg->length = plen;
+ len -= plen;
+ ctx->used += plen;
+ copied += plen;
+ sgl->cur++;
+ size -= plen;
+ ctx->merge = plen & (PAGE_SIZE - 1);
+ }
+ }
+
+ err = 0;
+
+ ctx->more = msg->msg_flags & MSG_MORE;
+
+unlock:
+ akcipher_data_wakeup(sk);
+ release_sock(sk);
+
+ return err ?: copied;
+}
+
+static ssize_t akcipher_sendpage(struct socket *sock, struct page *page,
+ int offset, size_t size, int flags)
+{
+ struct sock *sk = sock->sk;
+ struct alg_sock *ask = alg_sk(sk);
+ struct akcipher_ctx *ctx = ask->private;
+ struct akcipher_sg_list *sgl = &ctx->tsgl;
+ int err = 0;
+
+ if (flags & MSG_SENDPAGE_NOTLAST)
+ flags |= MSG_MORE;
+
+ if (sgl->cur >= ALG_MAX_PAGES)
+ return -E2BIG;
+
+ lock_sock(sk);
+ if (!ctx->more && ctx->used)
+ goto unlock;
+
+ if (!size)
+ goto done;
+
+ if (!akcipher_writable(sk)) {
+ /* user space sent too much data */
+ akcipher_put_sgl(sk);
+ err = -EMSGSIZE;
+ goto unlock;
+ }
+
+ ctx->merge = 0;
+
+ get_page(page);
+ sg_set_page(sgl->sg + sgl->cur, page, size, offset);
+ sgl->cur++;
+ ctx->used += size;
+
+done:
+ ctx->more = flags & MSG_MORE;
+unlock:
+ akcipher_data_wakeup(sk);
+ release_sock(sk);
+
+ return err ? err : size;
+}
+
+static int akcipher_recvmsg(struct socket *sock, struct msghdr *msg,
+ size_t ignored, int flags)
+{
+ struct sock *sk = sock->sk;
+ struct alg_sock *ask = alg_sk(sk);
+ struct akcipher_ctx *ctx = ask->private;
+ struct akcipher_sg_list *sgl = &ctx->tsgl;
+ unsigned int i = 0;
+ int err;
+ unsigned long used = 0;
+ size_t usedpages = 0;
+ unsigned int cnt = 0;
+
+ /* Limit number of IOV blocks to be accessed below */
+ if (msg->msg_iter.nr_segs > ALG_MAX_PAGES)
+ return -ENOMSG;
+
+ lock_sock(sk);
+
+ if (ctx->more) {
+ err = akcipher_wait_for_data(sk, flags);
+ if (err)
+ goto unlock;
+ }
+
+ used = ctx->used;
+
+ /* convert iovecs of output buffers into scatterlists */
+ while (iov_iter_count(&msg->msg_iter)) {
+ /* make one iovec available as scatterlist */
+ err = af_alg_make_sg(&ctx->rsgl[cnt], &msg->msg_iter,
+ iov_iter_count(&msg->msg_iter));
+ if (err < 0)
+ goto unlock;
+ usedpages += err;
+ /* chain the new scatterlist with previous one */
+ if (cnt)
+ af_alg_link_sg(&ctx->rsgl[cnt - 1], &ctx->rsgl[cnt]);
+
+ iov_iter_advance(&msg->msg_iter, err);
+ cnt++;
+ }
+
+ sg_mark_end(sgl->sg + sgl->cur - 1);
+
+ akcipher_request_set_crypt(&ctx->req, sgl->sg, ctx->rsgl[0].sg, used,
+ usedpages);
+ switch (ctx->op) {
+ case ALG_OP_VERIFY:
+ err = crypto_akcipher_verify(&ctx->req);
+ break;
+ case ALG_OP_SIGN:
+ err = crypto_akcipher_sign(&ctx->req);
+ break;
+ case ALG_OP_ENCRYPT:
+ err = crypto_akcipher_encrypt(&ctx->req);
+ break;
+ case ALG_OP_DECRYPT:
+ err = crypto_akcipher_decrypt(&ctx->req);
+ break;
+ default:
+ err = -EFAULT;
+ goto unlock;
+ }
+
+ err = af_alg_wait_for_completion(err, &ctx->completion);
+
+ if (err) {
+ /* EBADMSG implies a valid cipher operation took place */
+ if (err == -EBADMSG)
+ akcipher_put_sgl(sk);
+ goto unlock;
+ }
+
+ akcipher_put_sgl(sk);
+
+unlock:
+ for (i = 0; i < cnt; i++)
+ af_alg_free_sg(&ctx->rsgl[i]);
+
+ akcipher_wmem_wakeup(sk);
+ release_sock(sk);
+
+ return err ? err : ctx->req.dst_len;
+}
+
+static unsigned int akcipher_poll(struct file *file, struct socket *sock,
+ poll_table *wait)
+{
+ struct sock *sk = sock->sk;
+ struct alg_sock *ask = alg_sk(sk);
+ struct akcipher_ctx *ctx = ask->private;
+ unsigned int mask = 0;
+
+ sock_poll_wait(file, sk_sleep(sk), wait);
+
+ if (!ctx->more)
+ mask |= POLLIN | POLLRDNORM;
+
+ if (akcipher_writable(sk))
+ mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
+
+ return mask;
+}
+
+static struct proto_ops algif_akcipher_ops = {
+ .family = PF_ALG,
+
+ .connect = sock_no_connect,
+ .socketpair = sock_no_socketpair,
+ .getname = sock_no_getname,
+ .ioctl = sock_no_ioctl,
+ .listen = sock_no_listen,
+ .shutdown = sock_no_shutdown,
+ .getsockopt = sock_no_getsockopt,
+ .mmap = sock_no_mmap,
+ .bind = sock_no_bind,
+ .accept = sock_no_accept,
+ .setsockopt = sock_no_setsockopt,
+
+ .release = af_alg_release,
+ .sendmsg = akcipher_sendmsg,
+ .sendpage = akcipher_sendpage,
+ .recvmsg = akcipher_recvmsg,
+ .poll = akcipher_poll,
+};
+
+static void *akcipher_bind(const char *name, u32 type, u32 mask)
+{
+ return crypto_alloc_akcipher(name, type, mask);
+}
+
+static void akcipher_release(void *private)
+{
+ crypto_free_akcipher(private);
+}
+
+static int akcipher_setprivkey(void *private, const u8 *key,
+ unsigned int keylen)
+{
+ return crypto_akcipher_set_priv_key(private, key, keylen);
+}
+
+static int akcipher_setpubkey(void *private, const u8 *key, unsigned int keylen)
+{
+ return crypto_akcipher_set_pub_key(private, key, keylen);
+}
+
+static void akcipher_sock_destruct(struct sock *sk)
+{
+ struct alg_sock *ask = alg_sk(sk);
+ struct akcipher_ctx *ctx = ask->private;
+
+ akcipher_put_sgl(sk);
+ sock_kfree_s(sk, ctx, ctx->len);
+ af_alg_release_parent(sk);
+}
+
+static int akcipher_accept_parent(void *private, struct sock *sk)
+{
+ struct akcipher_ctx *ctx;
+ struct alg_sock *ask = alg_sk(sk);
+ unsigned int len = sizeof(*ctx) + crypto_akcipher_reqsize(private);
+
+ ctx = sock_kmalloc(sk, len, GFP_KERNEL);
+ if (!ctx)
+ return -ENOMEM;
+ memset(ctx, 0, len);
+
+ ctx->len = len;
+ ctx->used = 0;
+ ctx->more = 0;
+ ctx->merge = 0;
+ ctx->op = 0;
+ ctx->tsgl.cur = 0;
+ af_alg_init_completion(&ctx->completion);
+ sg_init_table(ctx->tsgl.sg, ALG_MAX_PAGES);
+
+ ask->private = ctx;
+
+ akcipher_request_set_tfm(&ctx->req, private);
+ akcipher_request_set_callback(&ctx->req, CRYPTO_TFM_REQ_MAY_BACKLOG,
+ af_alg_complete, &ctx->completion);
+
+ sk->sk_destruct = akcipher_sock_destruct;
+
+ return 0;
+}
+
+static const struct af_alg_type algif_type_akcipher = {
+ .bind = akcipher_bind,
+ .release = akcipher_release,
+ .setkey = akcipher_setprivkey,
+ .setpubkey = akcipher_setpubkey,
+ .accept = akcipher_accept_parent,
+ .ops = &algif_akcipher_ops,
+ .name = "akcipher",
+ .owner = THIS_MODULE
+};
+
+static int __init algif_akcipher_init(void)
+{
+ return af_alg_register_type(&algif_type_akcipher);
+}
+
+static void __exit algif_akcipher_exit(void)
+{
+ int err = af_alg_unregister_type(&algif_type_akcipher);
+
+ WARN_ON(err);
+}
+
+module_init(algif_akcipher_init);
+module_exit(algif_akcipher_exit);
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Stephan Mueller <[email protected]>");
+MODULE_DESCRIPTION("Asymmetric kernel crypto API user space interface");
From: Stephan Mueller <[email protected]>
For supporting asymmetric ciphers, user space must be able to set the
public key. The patch adds a new setsockopt call for setting the public
key.
Signed-off-by: Stephan Mueller <[email protected]>
Signed-off-by: Tadeusz Struk <[email protected]>
---
crypto/af_alg.c | 18 +++++++++++++-----
include/crypto/if_alg.h | 1 +
2 files changed, 14 insertions(+), 5 deletions(-)
diff --git a/crypto/af_alg.c b/crypto/af_alg.c
index f5e18c2..24dc082 100644
--- a/crypto/af_alg.c
+++ b/crypto/af_alg.c
@@ -202,13 +202,17 @@ unlock:
}
static int alg_setkey(struct sock *sk, char __user *ukey,
- unsigned int keylen)
+ unsigned int keylen,
+ int (*setkey)(void *private, const u8 *key,
+ unsigned int keylen))
{
struct alg_sock *ask = alg_sk(sk);
- const struct af_alg_type *type = ask->type;
u8 *key;
int err;
+ if (!setkey)
+ return -ENOPROTOOPT;
+
key = sock_kmalloc(sk, keylen, GFP_KERNEL);
if (!key)
return -ENOMEM;
@@ -217,7 +221,7 @@ static int alg_setkey(struct sock *sk, char __user *ukey,
if (copy_from_user(key, ukey, keylen))
goto out;
- err = type->setkey(ask->private, key, keylen);
+ err = setkey(ask->private, key, keylen);
out:
sock_kzfree_s(sk, key, keylen);
@@ -247,10 +251,14 @@ static int alg_setsockopt(struct socket *sock, int level, int optname,
case ALG_SET_KEY:
if (sock->state == SS_CONNECTED)
goto unlock;
- if (!type->setkey)
+
+ err = alg_setkey(sk, optval, optlen, type->setkey);
+ break;
+ case ALG_SET_PUBKEY:
+ if (sock->state == SS_CONNECTED)
goto unlock;
- err = alg_setkey(sk, optval, optlen);
+ err = alg_setkey(sk, optval, optlen, type->setpubkey);
break;
case ALG_SET_AEAD_AUTHSIZE:
if (sock->state == SS_CONNECTED)
diff --git a/include/crypto/if_alg.h b/include/crypto/if_alg.h
index a2bfd78..6c3e6e7 100644
--- a/include/crypto/if_alg.h
+++ b/include/crypto/if_alg.h
@@ -52,6 +52,7 @@ struct af_alg_type {
void *(*bind)(const char *name, u32 type, u32 mask);
void (*release)(void *private);
int (*setkey)(void *private, const u8 *key, unsigned int keylen);
+ int (*setpubkey)(void *private, const u8 *key, unsigned int keylen);
int (*accept)(void *private, struct sock *sk);
int (*accept_nokey)(void *private, struct sock *sk);
int (*setauthsize)(void *private, unsigned int authsize);
Hi,
[auto build test ERROR on cryptodev/master]
[also build test ERROR on v4.7-rc4 next-20160623]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]
url: https://github.com/0day-ci/linux/commits/Tadeusz-Struk/crypto-algif-add-akcipher/20160624-065803
base: https://git.kernel.org/pub/scm/linux/kernel/git/herbert/cryptodev-2.6.git master
config: x86_64-allmodconfig (attached as .config)
compiler: gcc-6 (Debian 6.1.1-1) 6.1.1 20160430
reproduce:
# save the attached .config to linux build tree
make ARCH=x86_64
All error/warnings (new ones prefixed by >>):
crypto/algif_akcipher.c: In function 'asym_key_encrypt':
>> crypto/algif_akcipher.c:326:9: error: variable 'params' has initializer but incomplete type
struct kernel_pkey_params params = {0};
^~~~~~~~~~~~~~~~~~
>> crypto/algif_akcipher.c:326:38: warning: excess elements in struct initializer
struct kernel_pkey_params params = {0};
^
crypto/algif_akcipher.c:326:38: note: (near initialization for 'params')
>> crypto/algif_akcipher.c:326:28: error: storage size of 'params' isn't known
struct kernel_pkey_params params = {0};
^~~~~~
>> crypto/algif_akcipher.c:352:8: error: implicit declaration of function 'encrypt_blob' [-Werror=implicit-function-declaration]
ret = encrypt_blob(¶ms, in, out);
^~~~~~~~~~~~
>> crypto/algif_akcipher.c:326:28: warning: unused variable 'params' [-Wunused-variable]
struct kernel_pkey_params params = {0};
^~~~~~
crypto/algif_akcipher.c: In function 'asym_key_decrypt':
crypto/algif_akcipher.c:366:9: error: variable 'params' has initializer but incomplete type
struct kernel_pkey_params params = {0};
^~~~~~~~~~~~~~~~~~
crypto/algif_akcipher.c:366:38: warning: excess elements in struct initializer
struct kernel_pkey_params params = {0};
^
crypto/algif_akcipher.c:366:38: note: (near initialization for 'params')
crypto/algif_akcipher.c:366:28: error: storage size of 'params' isn't known
struct kernel_pkey_params params = {0};
^~~~~~
>> crypto/algif_akcipher.c:392:8: error: implicit declaration of function 'decrypt_blob' [-Werror=implicit-function-declaration]
ret = decrypt_blob(¶ms, in, out);
^~~~~~~~~~~~
crypto/algif_akcipher.c:366:28: warning: unused variable 'params' [-Wunused-variable]
struct kernel_pkey_params params = {0};
^~~~~~
crypto/algif_akcipher.c: In function 'asym_key_sign':
crypto/algif_akcipher.c:406:9: error: variable 'params' has initializer but incomplete type
struct kernel_pkey_params params = {0};
^~~~~~~~~~~~~~~~~~
crypto/algif_akcipher.c:406:38: warning: excess elements in struct initializer
struct kernel_pkey_params params = {0};
^
crypto/algif_akcipher.c:406:38: note: (near initialization for 'params')
crypto/algif_akcipher.c:406:28: error: storage size of 'params' isn't known
struct kernel_pkey_params params = {0};
^~~~~~
>> crypto/algif_akcipher.c:432:8: error: implicit declaration of function 'create_signature' [-Werror=implicit-function-declaration]
ret = create_signature(¶ms, in, out);
^~~~~~~~~~~~~~~~
crypto/algif_akcipher.c:406:28: warning: unused variable 'params' [-Wunused-variable]
struct kernel_pkey_params params = {0};
^~~~~~
crypto/algif_akcipher.c: In function 'asym_key_verify':
>> crypto/algif_akcipher.c:460:5: error: 'struct public_key_signature' has no member named 'encoding'
sig.encoding = "pkcs1";
^
cc1: some warnings being treated as errors
vim +/params +326 crypto/algif_akcipher.c
320
321 return err ? err : size;
322 }
323
324 static int asym_key_encrypt(const struct key *key, struct akcipher_request *req)
325 {
> 326 struct kernel_pkey_params params = {0};
327 char *src = NULL, *dst = NULL, *in, *out;
328 int ret;
329
330 if (!sg_is_last(req->src)) {
331 src = kmalloc(req->src_len, GFP_KERNEL);
332 if (!src)
333 return -ENOMEM;
334 scatterwalk_map_and_copy(src, req->src, 0, req->src_len, 0);
335 in = src;
336 } else {
337 in = sg_virt(req->src);
338 }
339 if (!sg_is_last(req->dst)) {
340 dst = kmalloc(req->dst_len, GFP_KERNEL);
341 if (!dst) {
342 kfree(src);
343 return -ENOMEM;
344 }
345 out = dst;
346 } else {
347 out = sg_virt(req->dst);
348 }
349 params.key = (struct key *)key;
350 params.in_len = req->src_len;
351 params.out_len = req->dst_len;
> 352 ret = encrypt_blob(¶ms, in, out);
353 if (ret)
354 goto free;
355
356 if (dst)
357 scatterwalk_map_and_copy(dst, req->dst, 0, req->dst_len, 1);
358 free:
359 kfree(src);
360 kfree(dst);
361 return ret;
362 }
363
364 static int asym_key_decrypt(const struct key *key, struct akcipher_request *req)
365 {
> 366 struct kernel_pkey_params params = {0};
367 char *src = NULL, *dst = NULL, *in, *out;
368 int ret;
369
370 if (!sg_is_last(req->src)) {
371 src = kmalloc(req->src_len, GFP_KERNEL);
372 if (!src)
373 return -ENOMEM;
374 scatterwalk_map_and_copy(src, req->src, 0, req->src_len, 0);
375 in = src;
376 } else {
377 in = sg_virt(req->src);
378 }
379 if (!sg_is_last(req->dst)) {
380 dst = kmalloc(req->dst_len, GFP_KERNEL);
381 if (!dst) {
382 kfree(src);
383 return -ENOMEM;
384 }
385 out = dst;
386 } else {
387 out = sg_virt(req->dst);
388 }
389 params.key = (struct key *)key;
390 params.in_len = req->src_len;
391 params.out_len = req->dst_len;
> 392 ret = decrypt_blob(¶ms, in, out);
393 if (ret)
394 goto free;
395
396 if (dst)
397 scatterwalk_map_and_copy(dst, req->dst, 0, req->dst_len, 1);
398 free:
399 kfree(src);
400 kfree(dst);
401 return ret;
402 }
403
404 static int asym_key_sign(const struct key *key, struct akcipher_request *req)
405 {
> 406 struct kernel_pkey_params params = {0};
407 char *src = NULL, *dst = NULL, *in, *out;
408 int ret;
409
410 if (!sg_is_last(req->src)) {
411 src = kmalloc(req->src_len, GFP_KERNEL);
412 if (!src)
413 return -ENOMEM;
414 scatterwalk_map_and_copy(src, req->src, 0, req->src_len, 0);
415 in = src;
416 } else {
417 in = sg_virt(req->src);
418 }
419 if (!sg_is_last(req->dst)) {
420 dst = kmalloc(req->dst_len, GFP_KERNEL);
421 if (!dst) {
422 kfree(src);
423 return -ENOMEM;
424 }
425 out = dst;
426 } else {
427 out = sg_virt(req->dst);
428 }
429 params.key = (struct key *)key;
430 params.in_len = req->src_len;
431 params.out_len = req->dst_len;
> 432 ret = create_signature(¶ms, in, out);
433 if (ret)
434 goto free;
435
436 if (dst)
437 scatterwalk_map_and_copy(dst, req->dst, 0, req->dst_len, 1);
438 free:
439 kfree(src);
440 kfree(dst);
441 return ret;
442 }
443
444 static int asym_key_verify(const struct key *key, struct akcipher_request *req)
445 {
446 struct public_key_signature sig;
447 char *src = NULL, *in, digest[20];
448 int ret;
449
450 if (!sg_is_last(req->src)) {
451 src = kmalloc(req->src_len, GFP_KERNEL);
452 if (!src)
453 return -ENOMEM;
454 scatterwalk_map_and_copy(src, req->src, 0, req->src_len, 0);
455 in = src;
456 } else {
457 in = sg_virt(req->src);
458 }
459 sig.pkey_algo = "rsa";
> 460 sig.encoding = "pkcs1";
461 /* Need to find a way to pass the hash param */
462 sig.hash_algo = "sha1";
463 sig.digest_size = sizeof(digest);
---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation
Am Donnerstag, 23. Juni 2016, 15:55:26 schrieb Tadeusz Struk:
Hi Tadeusz,
> First four patches are a resend algif_akcipher from
> Stephan Mueller, with minor changes after rebase on top of 4.7-rc1.
The first four patches:
Acked-by: Stephan Mueller <[email protected]>
Ciao
Stephan
Tadeusz,
On Thu, 23 Jun 2016, Tadeusz Struk wrote:
> This patch adds support for asymmetric key type to AF_ALG.
> It will work as follows: A new PF_ALG socket options are
> added on top of existing ALG_SET_KEY and ALG_SET_PUBKEY, namely
> ALG_SET_KEY_ID and ALG_SET_PUBKEY_ID for setting public and
> private keys respectively. When these new options will be used
> the user, instead of providing the key material, will provide a
> key id and the key itself will be obtained from kernel keyring
> subsystem. The user will use the standard tools (keyctl tool
> or the keyctl syscall) for key instantiation and to obtain the
> key id. The key id can also be obtained by reading the
> /proc/keys file.
>
> When a key corresponding to the given keyid is found, it is stored
> in the socket context and subsequent crypto operation invoked by the
> user will use the new asymmetric accessor functions instead of akcipher
> api. The asymmetric subtype can internally use akcipher api or
> invoke operations defined by a given subtype, depending on the
> key type.
>
> Signed-off-by: Tadeusz Struk <[email protected]>
> ---
> crypto/af_alg.c | 10 ++
> crypto/algif_akcipher.c | 212 ++++++++++++++++++++++++++++++++++++++++++-
> include/crypto/if_alg.h | 1
> include/uapi/linux/if_alg.h | 2
> 4 files changed, 220 insertions(+), 5 deletions(-)
>
> diff --git a/crypto/algif_akcipher.c b/crypto/algif_akcipher.c
> index 2b8d37e..106f715 100644
> --- a/crypto/algif_akcipher.c
> +++ b/crypto/algif_akcipher.c
> +static int asym_key_verify(const struct key *key, struct akcipher_request *req)
> +{
> + struct public_key_signature sig;
> + char *src = NULL, *in, digest[20];
> + int ret;
> +
> + if (!sg_is_last(req->src)) {
> + src = kmalloc(req->src_len, GFP_KERNEL);
> + if (!src)
> + return -ENOMEM;
> + scatterwalk_map_and_copy(src, req->src, 0, req->src_len, 0);
> + in = src;
> + } else {
> + in = sg_virt(req->src);
> + }
> + sig.pkey_algo = "rsa";
> + sig.encoding = "pkcs1";
> + /* Need to find a way to pass the hash param */
Comment still needed?
> + sig.hash_algo = "sha1";
> + sig.digest_size = sizeof(digest);
> + sig.digest = digest;
> + sig.s_size = req->src_len;
> + sig.s = src;
> + ret = verify_signature(key, &sig);
> + if (!ret) {
> + req->dst_len = sizeof(digest);
I think you fixed the BUG_ON() problem but there's still an issue with the
handling of the digest. Check the use of sig->digest in
public_key_verify_signature(), it's an input not an output. Right now it
looks like 20 uninitialized bytes are compared with the computed digest
within verify_signature, and then the unintialized bytes are copied to
req->dst here.
With some modifications to public_key_verify_signature you could get the
digest you need, but I'm not sure if verification with a hardware key
(like a key in a TPM) can or can not provide the digest needed. Maybe this
is why the verify_signature hook in struct asymmetric_key_subtype is
optional.
> + scatterwalk_map_and_copy(digest, req->dst, 0, req->dst_len, 1);
> + }
> + kfree(src);
> + return ret;
> +}
> +
--
Mat Martineau
Intel OTC
Hi Mat,
On 06/29/2016 11:43 AM, Mat Martineau wrote:
>> + ret = verify_signature(key, &sig);
>> + if (!ret) {
>> + req->dst_len = sizeof(digest);
>
> I think you fixed the BUG_ON() problem but there's still an issue with
> the handling of the digest. Check the use of sig->digest in
> public_key_verify_signature(), it's an input not an output. Right now it
> looks like 20 uninitialized bytes are compared with the computed digest
> within verify_signature, and then the unintialized bytes are copied to
> req->dst here.
>
> With some modifications to public_key_verify_signature you could get the
> digest you need, but I'm not sure if verification with a hardware key
> (like a key in a TPM) can or can not provide the digest needed. Maybe
> this is why the verify_signature hook in struct asymmetric_key_subtype
> is optional.
>
>> + scatterwalk_map_and_copy(digest, req->dst, 0, req->dst_len, 1);
>> + }
So it looks like the only thing that we need to return to the user in
this case is the return code. Do you agree?
Thanks,
--
TS
On Tue, 5 Jul 2016, Tadeusz Struk wrote:
> Hi Mat,
> On 06/29/2016 11:43 AM, Mat Martineau wrote:
>>> + ret = verify_signature(key, &sig);
>>> + if (!ret) {
>>> + req->dst_len = sizeof(digest);
>>
>> I think you fixed the BUG_ON() problem but there's still an issue with
>> the handling of the digest. Check the use of sig->digest in
>> public_key_verify_signature(), it's an input not an output. Right now it
>> looks like 20 uninitialized bytes are compared with the computed digest
>> within verify_signature, and then the unintialized bytes are copied to
>> req->dst here.
>>
>> With some modifications to public_key_verify_signature you could get the
>> digest you need, but I'm not sure if verification with a hardware key
>> (like a key in a TPM) can or can not provide the digest needed. Maybe
>> this is why the verify_signature hook in struct asymmetric_key_subtype
>> is optional.
>>
>>> + scatterwalk_map_and_copy(digest, req->dst, 0, req->dst_len, 1);
>>> + }
>
> So it looks like the only thing that we need to return to the user in
> this case is the return code. Do you agree?
The way verify_signature is implemented today, the only output is the
return code. For verify, maybe no read is required (just sendmsg() and
check the return code).
But this isn't the extent of the problem: verify_signature needs both the
signature to be verified and the expected hash as inputs. How is the
expected hash provided? Would you include it as a cmsg header?
ALG_OP_VERIFY should have consistent inputs and outputs whether the key
was set with ALG_SET_KEY_ID or ALG_SET_KEY.
--
Mat Martineau
Intel OTC
Hi Mat,
On 07/06/2016 12:38 PM, Mat Martineau wrote:
>> So it looks like the only thing that we need to return to the user in
>> this case is the return code. Do you agree?
>
> The way verify_signature is implemented today, the only output is the
> return code. For verify, maybe no read is required (just sendmsg() and
> check the return code).
>
> But this isn't the extent of the problem: verify_signature needs both
> the signature to be verified and the expected hash as inputs. How is the
> expected hash provided? Would you include it as a cmsg header?
> ALG_OP_VERIFY should have consistent inputs and outputs whether the key
> was set with ALG_SET_KEY_ID or ALG_SET_KEY.
The signature of verify_signature() is quite different from the other
new public key handlers, i.e. create_signature(), encrypt_blob(), and
decrypt_blob(). For verify_signature() we need the following parameters:
encrypted src, hash function to use, expected digest.
The expected digest could be optional if we would modify the
verify_signature() to return the decrypted buffer.
I think the best solution for now would be to just return -ENOPROTOOPT
for verify_signature in SET_KEY_ID mode.
All the four operations will be supported in the SET_KEY mode and
all but verify_signature() will be supported in the SET_KEY_ID mode.
This can added later if we will find a way to pass all parameters in a
consistent way. What do you think? If you are ok with that I will send a
new version soon.
Thanks,
--
TS
On Fri, 8 Jul 2016, Tadeusz Struk wrote:
> Hi Mat,
> On 07/06/2016 12:38 PM, Mat Martineau wrote:
>>> So it looks like the only thing that we need to return to the user in
>>> this case is the return code. Do you agree?
>>
>> The way verify_signature is implemented today, the only output is the
>> return code. For verify, maybe no read is required (just sendmsg() and
>> check the return code).
>>
>> But this isn't the extent of the problem: verify_signature needs both
>> the signature to be verified and the expected hash as inputs. How is the
>> expected hash provided? Would you include it as a cmsg header?
>> ALG_OP_VERIFY should have consistent inputs and outputs whether the key
>> was set with ALG_SET_KEY_ID or ALG_SET_KEY.
>
> The signature of verify_signature() is quite different from the other
> new public key handlers, i.e. create_signature(), encrypt_blob(), and
> decrypt_blob(). For verify_signature() we need the following parameters:
> encrypted src, hash function to use, expected digest.
> The expected digest could be optional if we would modify the
> verify_signature() to return the decrypted buffer.
> I think the best solution for now would be to just return -ENOPROTOOPT
> for verify_signature in SET_KEY_ID mode.
> All the four operations will be supported in the SET_KEY mode and
> all but verify_signature() will be supported in the SET_KEY_ID mode.
> This can added later if we will find a way to pass all parameters in a
> consistent way. What do you think? If you are ok with that I will send a
> new version soon.
Are the inputs and outputs defined for ALG_OP_VERIFY in SET_KEY mode going
to work for hardware keys (like TPM) in SET_KEY_ID mode? That's needed if
the verify SET_KEY_ID mode is to be added later.
--
Mat Martineau
Intel OTC
On 07/08/2016 09:38 AM, Mat Martineau wrote:
> Are the inputs and outputs defined for ALG_OP_VERIFY in SET_KEY mode
> going to work for hardware keys (like TPM) in SET_KEY_ID mode? That's
> needed if the verify SET_KEY_ID mode is to be added later.
Yes, we will just need to change the verify_signature() in public_key.c
to be consistent with the rest of handlers. What we need really is the
src (encrypted input), key (or key id), and an output buffer where we
can copy the result to.
Thanks,
--
TS