2013-12-11 10:29:12

by Daniel Borkmann

Subject: [PATCH cryptodev] crypto: arch - use crypto_memneq instead of memcmp

Replace remaining occurences (just as we did in crypto/) under arch/*/crypto/
that make use of memcmp() for comparing keys or authentication tags for
usage with crypto_memneq(). It can simply be used as a drop-in replacement
for the normal memcmp().

Signed-off-by: Daniel Borkmann <[email protected]>
Cc: James Yonan <[email protected]>
---
arch/s390/crypto/des_s390.c | 6 +++---
arch/x86/crypto/aesni-intel_glue.c | 2 +-
2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/s390/crypto/des_s390.c b/arch/s390/crypto/des_s390.c
index bcca01c..200f2a1 100644
--- a/arch/s390/crypto/des_s390.c
+++ b/arch/s390/crypto/des_s390.c
@@ -237,9 +237,9 @@ static int des3_setkey(struct crypto_tfm *tfm, const u8 *key,
struct s390_des_ctx *ctx = crypto_tfm_ctx(tfm);
u32 *flags = &tfm->crt_flags;

- if (!(memcmp(key, &key[DES_KEY_SIZE], DES_KEY_SIZE) &&
- memcmp(&key[DES_KEY_SIZE], &key[DES_KEY_SIZE * 2],
- DES_KEY_SIZE)) &&
+ if (!(crypto_memneq(key, &key[DES_KEY_SIZE], DES_KEY_SIZE) &&
+ crypto_memneq(&key[DES_KEY_SIZE], &key[DES_KEY_SIZE * 2],
+ DES_KEY_SIZE)) &&
(*flags & CRYPTO_TFM_REQ_WEAK_KEY)) {
*flags |= CRYPTO_TFM_RES_WEAK_KEY;
return -EINVAL;
diff --git a/arch/x86/crypto/aesni-intel_glue.c b/arch/x86/crypto/aesni-intel_glue.c
index 835488b..aba34b8 100644
--- a/arch/x86/crypto/aesni-intel_glue.c
+++ b/arch/x86/crypto/aesni-intel_glue.c
@@ -1001,7 +1001,7 @@ static int __driver_rfc4106_decrypt(struct aead_request *req)
authTag, auth_tag_len);

/* Compare generated tag with passed in tag. */
- retval = memcmp(src + tempCipherLen, authTag, auth_tag_len) ?
+ retval = crypto_memneq(src + tempCipherLen, authTag, auth_tag_len) ?
-EBADMSG : 0;

if (one_entry_in_sg) {
--
1.8.3.1

2013-12-20 14:07:50

by Herbert Xu

Subject: Re: [PATCH cryptodev] crypto: arch - use crypto_memneq instead of memcmp

On Wed, Dec 11, 2013 at 11:28:59AM +0100, Daniel Borkmann wrote:
> Replace remaining occurences (just as we did in crypto/) under arch/*/crypto/
> that make use of memcmp() for comparing keys or authentication tags for
> usage with crypto_memneq(). It can simply be used as a drop-in replacement
> for the normal memcmp().
>
> Signed-off-by: Daniel Borkmann <[email protected]>
> Cc: James Yonan <[email protected]>

Patch applied. Thanks!
--
Email: Herbert Xu <[email protected]>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt