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 <da...@sigma-star.at>
---
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
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