[CRYPTO] authenc: Fix hash verification
The previous code incorrectly included the hash in the verification which
also meant that we'd crash and burn when it comes to actually verifying
the hash since we'd go past the end of the SG list.
This patch fixes that by subtracting authsize from cryptlen at the start.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/crypto/authenc.c b/crypto/authenc.c
index a61dea1..82e03ff 100644
--- a/crypto/authenc.c
+++ b/crypto/authenc.c
@@ -158,7 +158,8 @@
return crypto_authenc_hash(req);
}
-static int crypto_authenc_verify(struct aead_request *req)
+static int crypto_authenc_verify(struct aead_request *req,
+ unsigned int cryptlen)
{
struct crypto_aead *authenc = crypto_aead_reqtfm(req);
struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
@@ -170,7 +171,6 @@
u8 *ohash = aead_request_ctx(req);
u8 *ihash;
struct scatterlist *src = req->src;
- unsigned int cryptlen = req->cryptlen;
unsigned int authsize;
int err;
@@ -214,16 +214,22 @@
struct crypto_aead *authenc = crypto_aead_reqtfm(req);
struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
struct ablkcipher_request *abreq = aead_request_ctx(req);
+ unsigned int cryptlen = req->cryptlen;
+ unsigned int authsize = crypto_aead_authsize(authenc);
int err;
- err = crypto_authenc_verify(req);
+ if (cryptlen < authsize)
+ return -EINVAL;
+ cryptlen -= authsize;
+
+ err = crypto_authenc_verify(req, cryptlen);
if (err)
return err;
ablkcipher_request_set_tfm(abreq, ctx->enc);
ablkcipher_request_set_callback(abreq, aead_request_flags(req),
crypto_authenc_decrypt_done, req);
- ablkcipher_request_set_crypt(abreq, req->src, req->dst, req->cryptlen,
+ ablkcipher_request_set_crypt(abreq, req->src, req->dst, cryptlen,
req->iv);
return crypto_ablkcipher_decrypt(abreq);
