crypto: des3_ede - permit weak keys unless REQ_WEAK_KEY set

While its a slightly insane to bypass the key1 == key2 || key2 == key3 check in triple-des, since it reduces it to the same strength as des, some folks do need to do this from time to time for backwards compatibility with des. My own case is FIPS CAVS test vectors. Many triple-des test vectors use a single key, replicated 3x. In order to get the expected results, des3_ede_setkey() needs to only reject weak keys if the CRYPTO_TFM_REQ_WEAK_KEY flag is set. Also sets a more appropriate RES flag when a weak key is found. Signed-off-by: Jarod Wilson <[email protected]> Signed-off-by: Herbert Xu <[email protected]>
redpig · Dec 25, 2008 · ad79cdd · ad79cdd
1 parent bd9d20d
commit ad79cdd
Showing 1 changed file with 3 additions and 2 deletions.
diff --git a/crypto/des_generic.c b/crypto/des_generic.c
@@ -868,9 +868,10 @@ static int des3_ede_setkey(struct crypto_tfm *tfm, const u8 *key,
 	u32 *flags = &tfm->crt_flags;
 
 	if (unlikely(!((K[0] ^ K[2]) | (K[1] ^ K[3])) ||
-		     !((K[2] ^ K[4]) | (K[3] ^ K[5]))))
+		     !((K[2] ^ K[4]) | (K[3] ^ K[5]))) &&
+		     (*flags & CRYPTO_TFM_REQ_WEAK_KEY))
 	{
-		*flags |= CRYPTO_TFM_RES_BAD_KEY_SCHED;
+		*flags |= CRYPTO_TFM_RES_WEAK_KEY;
 		return -EINVAL;
 	}