From: "Jason A. Donenfeld" <Jason@zx2c4.com>
Date: Sun, 11 Jun 2017 23:20:23 +0200
Subject: [PATCH] crypto: rsa-pkcs1pad - use constant time memory comparison
for MACs
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References: bnc#1060662
Patch-mainline: 4.12.2
Git-commit: fec17cb2231733174e039ad9054fa16bb358e2ec
commit fec17cb2231733174e039ad9054fa16bb358e2ec upstream.
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: Herbert Xu <herbert@gondor.apana.org.au>
Cc: linux-crypto@vger.kernel.org
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
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;
--
2.14.2