crypto: qat - Ensure ipad and opad are zeroed

The patch ad511e260a27b8e35d273cc0ecfe5a8ff9543181 (crypto: qat -
Fix incorrect uses of memzero_explicit) broke hashing because the
code was in fact overwriting the qat_auth_state variable.

In fact there is no reason for the variable to exist anyway since
all we are using it for is to store ipad and opad.  So we could
simply create ipad and opad directly and avoid this whole mess.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --git a/drivers/crypto/qat/qat_common/qat_algs.c b/drivers/crypto/qat/qat_common/qat_algs.c
index a0d95f329094bf0577b3d4a91acf1ad71cf8d148..e2c4b254ac411b9eaf8f42931e0aa349e484a9ac 100644 (file)
--- a/drivers/crypto/qat/qat_common/qat_algs.c
+++ b/drivers/crypto/qat/qat_common/qat_algs.c
@@ -160,33 +160,30 @@ static int qat_alg_do_precomputes(struct icp_qat_hw_auth_algo_blk *hash,
                                  const uint8_t *auth_key,
                                  unsigned int auth_keylen)
 {
-       struct qat_auth_state auth_state;
        SHASH_DESC_ON_STACK(shash, ctx->hash_tfm);
        struct sha1_state sha1;
        struct sha256_state sha256;
        struct sha512_state sha512;
        int block_size = crypto_shash_blocksize(ctx->hash_tfm);
        int digest_size = crypto_shash_digestsize(ctx->hash_tfm);
-       uint8_t *ipad = auth_state.data;
-       uint8_t *opad = ipad + block_size;
+       char ipad[block_size];
+       char opad[block_size];
        __be32 *hash_state_out;
        __be64 *hash512_state_out;
        int i, offset;
 
-       memset(auth_state.data, 0, sizeof(auth_state.data));
+       memset(ipad, 0, block_size);
+       memset(opad, 0, block_size);
        shash->tfm = ctx->hash_tfm;
        shash->flags = 0x0;
 
        if (auth_keylen > block_size) {
-               char buff[SHA512_BLOCK_SIZE];
                int ret = crypto_shash_digest(shash, auth_key,
-                                             auth_keylen, buff);
+                                             auth_keylen, ipad);
                if (ret)
                        return ret;
 
-               memcpy(ipad, buff, digest_size);
-               memcpy(opad, buff, digest_size);
-               memzero_explicit(buff, sizeof(buff));
+               memcpy(opad, ipad, digest_size);
        } else {
                memcpy(ipad, auth_key, auth_keylen);
                memcpy(opad, auth_key, auth_keylen);