Re: [PATCH] rsa-pkcs1pad: use constant time memory comparison for MACs

[Herbert Xu]

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 
> Suggested-by: Stephan Müller 
> Cc: sta...@vger.kernel.org
> Cc: Herbert Xu 
> Cc: linux-crypto@vger.kernel.org

Patch applied.  Thanks.
-- 
Email: Herbert Xu 
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt

[PATCH] rsa-pkcs1pad: use constant time memory comparison for MACs

[Jason A. Donenfeld]

Otherwise, we enable all sorts of forgeries via timing attack.

Signed-off-by: Jason A. Donenfeld 
Suggested-by: Stephan Müller 
Cc: sta...@vger.kernel.org
Cc: Herbert Xu 
Cc: linux-crypto@vger.kernel.org
---
 crypto/rsa-pkcs1pad.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

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;
-- 
2.13.1