Using non-constant time memcmp() makes the verification of the authentication tag in the decrypt path vulnerable to timing attacks. Fix this by using crypto_memneq() instead. Signed-off-by: David Gstir <david@xxxxxxxxxxxxx> --- drivers/crypto/nx/nx-aes-ccm.c | 2 +- drivers/crypto/nx/nx-aes-gcm.c | 3 ++- 2 files changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/crypto/nx/nx-aes-ccm.c b/drivers/crypto/nx/nx-aes-ccm.c index 73ef49922788..7038f364acb5 100644 --- a/drivers/crypto/nx/nx-aes-ccm.c +++ b/drivers/crypto/nx/nx-aes-ccm.c @@ -409,7 +409,7 @@ static int ccm_nx_decrypt(struct aead_request *req, processed += to_process; } while (processed < nbytes); - rc = memcmp(csbcpb->cpb.aes_ccm.out_pat_or_mac, priv->oauth_tag, + rc = crypto_memneq(csbcpb->cpb.aes_ccm.out_pat_or_mac, priv->oauth_tag, authsize) ? -EBADMSG : 0; out: spin_unlock_irqrestore(&nx_ctx->lock, irq_flags); diff --git a/drivers/crypto/nx/nx-aes-gcm.c b/drivers/crypto/nx/nx-aes-gcm.c index eee624f589b6..abd465f479c4 100644 --- a/drivers/crypto/nx/nx-aes-gcm.c +++ b/drivers/crypto/nx/nx-aes-gcm.c @@ -21,6 +21,7 @@ #include <crypto/internal/aead.h> #include <crypto/aes.h> +#include <crypto/algapi.h> #include <crypto/scatterwalk.h> #include <linux/module.h> #include <linux/types.h> @@ -418,7 +419,7 @@ mac: itag, req->src, req->assoclen + nbytes, crypto_aead_authsize(crypto_aead_reqtfm(req)), SCATTERWALK_FROM_SG); - rc = memcmp(itag, otag, + rc = crypto_memneq(itag, otag, crypto_aead_authsize(crypto_aead_reqtfm(req))) ? -EBADMSG : 0; } -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-crypto" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
