[PATCH 1/2] crypto: fix cfb mode decryption

Dmitry Eremin-Solenikov
2018-10-20T07:10:02Z

crypto_cfb_decrypt_segment() incorrectly XOR'ed generated keystream with
IV, rather than with data stream, resulting in incorrect decryption.
Test vectors will be added in the next patch.

Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Cc: stable@vger.kernel.org
---
crypto/cfb.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/crypto/cfb.c b/crypto/cfb.c
index a0d68c09e1b9..fd4e8500e121 100644
--- a/crypto/cfb.c
+++ b/crypto/cfb.c
@@ -144,7 +144,7 @@ static int crypto_cfb_decrypt_segment(struct skcipher_walk *walk,

do {
crypto_cfb_encrypt_one(tfm, iv, dst);
- crypto_xor(dst, iv, bsize);
+ crypto_xor(dst, src, bsize);
iv = src;

src += bsize;
--
2.19.1