diff mbox

rsa-pkcs1pad: use constant time memory comparison for MACs

Message ID 20170611212023.31101-1-Jason@zx2c4.com (mailing list archive)
State New, archived
Headers show

Commit Message

Jason A. Donenfeld June 11, 2017, 9:20 p.m. UTC 
Otherwise, we enable all sorts of forgeries via timing attack.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Suggested-by: Stephan Müller <smueller@chronox.de>
Cc: stable@vger.kernel.org
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: linux-crypto@vger.kernel.org
---
 crypto/rsa-pkcs1pad.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Herbert Xu June 20, 2017, 3:38 a.m. UTC | #1 
On Sun, Jun 11, 2017 at 11:20:23PM +0200, Jason A. Donenfeld wrote:
> Otherwise, we enable all sorts of forgeries via timing attack.
> 
> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
> Suggested-by: Stephan Müller <smueller@chronox.de>
> Cc: stable@vger.kernel.org
> Cc: Herbert Xu <herbert@gondor.apana.org.au>
> Cc: linux-crypto@vger.kernel.org

Patch applied.  Thanks.
diff mbox

Patch

diff --git a/crypto/rsa-pkcs1pad.c b/crypto/rsa-pkcs1pad.c
index 8baab4307f7b..7830d304dff6 100644
--- a/crypto/rsa-pkcs1pad.c
+++ b/crypto/rsa-pkcs1pad.c
@@ -496,7 +496,7 @@  static int pkcs1pad_verify_complete(struct akcipher_request *req, int err)
 		goto done;
 	pos++;
 
-	if (memcmp(out_buf + pos, digest_info->data, digest_info->size))
+	if (crypto_memneq(out_buf + pos, digest_info->data, digest_info->size))
 		goto done;
 
 	pos += digest_info->size;