[PATCH 3.19.y-ckt 026/170] crypto: ccp - Limit the amount of information exported

From: Kamal Mostafa
Date: Fri Apr 01 2016 - 21:37:46 EST


3.19.8-ckt18 -stable review patch. If anyone has any objections, please let me know.

---8<------------------------------------------------------------

From: Tom Lendacky <thomas.lendacky@xxxxxxx>

commit d1662165ae612ec8b5f94a6b07e65ea58b6dce34 upstream.

Since the exported information can be exposed to user-space, instead of
exporting the entire request context only export the minimum information
needed.

Signed-off-by: Tom Lendacky <thomas.lendacky@xxxxxxx>
Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Kamal Mostafa <kamal@xxxxxxxxxxxxx>
---
drivers/crypto/ccp/ccp-crypto-aes-cmac.c | 16 +++++++++++-----
drivers/crypto/ccp/ccp-crypto-sha.c | 20 +++++++++++++++-----
drivers/crypto/ccp/ccp-crypto.h | 22 ++++++++++++++++++++++
3 files changed, 48 insertions(+), 10 deletions(-)

diff --git a/drivers/crypto/ccp/ccp-crypto-aes-cmac.c b/drivers/crypto/ccp/ccp-crypto-aes-cmac.c
index 504d6da..9d12fd4 100644
--- a/drivers/crypto/ccp/ccp-crypto-aes-cmac.c
+++ b/drivers/crypto/ccp/ccp-crypto-aes-cmac.c
@@ -204,9 +204,12 @@ static int ccp_aes_cmac_digest(struct ahash_request *req)
static int ccp_aes_cmac_export(struct ahash_request *req, void *out)
{
struct ccp_aes_cmac_req_ctx *rctx = ahash_request_ctx(req);
- struct ccp_aes_cmac_req_ctx *state = out;
+ struct ccp_aes_cmac_exp_ctx *state = out;

- *state = *rctx;
+ state->null_msg = rctx->null_msg;
+ memcpy(state->iv, rctx->iv, sizeof(state->iv));
+ state->buf_count = rctx->buf_count;
+ memcpy(state->buf, rctx->buf, sizeof(state->buf));

return 0;
}
@@ -214,9 +217,12 @@ static int ccp_aes_cmac_export(struct ahash_request *req, void *out)
static int ccp_aes_cmac_import(struct ahash_request *req, const void *in)
{
struct ccp_aes_cmac_req_ctx *rctx = ahash_request_ctx(req);
- const struct ccp_aes_cmac_req_ctx *state = in;
+ const struct ccp_aes_cmac_exp_ctx *state = in;

- *rctx = *state;
+ rctx->null_msg = state->null_msg;
+ memcpy(rctx->iv, state->iv, sizeof(rctx->iv));
+ rctx->buf_count = state->buf_count;
+ memcpy(rctx->buf, state->buf, sizeof(rctx->buf));

return 0;
}
@@ -358,7 +364,7 @@ int ccp_register_aes_cmac_algs(struct list_head *head)

halg = &alg->halg;
halg->digestsize = AES_BLOCK_SIZE;
- halg->statesize = sizeof(struct ccp_aes_cmac_req_ctx);
+ halg->statesize = sizeof(struct ccp_aes_cmac_exp_ctx);

base = &halg->base;
snprintf(base->cra_name, CRYPTO_MAX_ALG_NAME, "cmac(aes)");
diff --git a/drivers/crypto/ccp/ccp-crypto-sha.c b/drivers/crypto/ccp/ccp-crypto-sha.c
index 33e52f0..b934db9 100644
--- a/drivers/crypto/ccp/ccp-crypto-sha.c
+++ b/drivers/crypto/ccp/ccp-crypto-sha.c
@@ -196,9 +196,14 @@ static int ccp_sha_digest(struct ahash_request *req)
static int ccp_sha_export(struct ahash_request *req, void *out)
{
struct ccp_sha_req_ctx *rctx = ahash_request_ctx(req);
- struct ccp_sha_req_ctx *state = out;
+ struct ccp_sha_exp_ctx *state = out;

- *state = *rctx;
+ state->type = rctx->type;
+ state->msg_bits = rctx->msg_bits;
+ state->first = rctx->first;
+ memcpy(state->ctx, rctx->ctx, sizeof(state->ctx));
+ state->buf_count = rctx->buf_count;
+ memcpy(state->buf, rctx->buf, sizeof(state->buf));

return 0;
}
@@ -206,9 +211,14 @@ static int ccp_sha_export(struct ahash_request *req, void *out)
static int ccp_sha_import(struct ahash_request *req, const void *in)
{
struct ccp_sha_req_ctx *rctx = ahash_request_ctx(req);
- const struct ccp_sha_req_ctx *state = in;
+ const struct ccp_sha_exp_ctx *state = in;

- *rctx = *state;
+ rctx->type = state->type;
+ rctx->msg_bits = state->msg_bits;
+ rctx->first = state->first;
+ memcpy(rctx->ctx, state->ctx, sizeof(rctx->ctx));
+ rctx->buf_count = state->buf_count;
+ memcpy(rctx->buf, state->buf, sizeof(rctx->buf));

return 0;
}
@@ -413,7 +423,7 @@ static int ccp_register_sha_alg(struct list_head *head,

halg = &alg->halg;
halg->digestsize = def->digest_size;
- halg->statesize = sizeof(struct ccp_sha_req_ctx);
+ halg->statesize = sizeof(struct ccp_sha_exp_ctx);

base = &halg->base;
snprintf(base->cra_name, CRYPTO_MAX_ALG_NAME, "%s", def->name);
diff --git a/drivers/crypto/ccp/ccp-crypto.h b/drivers/crypto/ccp/ccp-crypto.h
index 9aa4ae1..7a0bb029 100644
--- a/drivers/crypto/ccp/ccp-crypto.h
+++ b/drivers/crypto/ccp/ccp-crypto.h
@@ -132,6 +132,15 @@ struct ccp_aes_cmac_req_ctx {
struct ccp_cmd cmd;
};

+struct ccp_aes_cmac_exp_ctx {
+ unsigned int null_msg;
+
+ u8 iv[AES_BLOCK_SIZE];
+
+ unsigned int buf_count;
+ u8 buf[AES_BLOCK_SIZE];
+};
+
/***** SHA related defines *****/
#define MAX_SHA_CONTEXT_SIZE SHA256_DIGEST_SIZE
#define MAX_SHA_BLOCK_SIZE SHA256_BLOCK_SIZE
@@ -174,6 +183,19 @@ struct ccp_sha_req_ctx {
struct ccp_cmd cmd;
};

+struct ccp_sha_exp_ctx {
+ enum ccp_sha_type type;
+
+ u64 msg_bits;
+
+ unsigned int first;
+
+ u8 ctx[MAX_SHA_CONTEXT_SIZE];
+
+ unsigned int buf_count;
+ u8 buf[MAX_SHA_BLOCK_SIZE];
+};
+
/***** Common Context Structure *****/
struct ccp_ctx {
int (*complete)(struct crypto_async_request *req, int ret);
--
2.7.4