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From:   Thara Gopinath <thara.gopinath@linaro.org>
To:     herbert@gondor.apana.org.au, davem@davemloft.net,
        bjorn.andersson@linaro.org
Cc:     ebiggers@google.com, ardb@kernel.org, sivaprak@codeaurora.org,
        linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH 1/6] drivers: crypto: qce: sha: Restore/save sha1_state/sha256_state with qce_sha_reqctx in export/import
Date:   Fri, 18 Dec 2020 22:30:22 -0500
Message-Id: <20201219033027.3066042-2-thara.gopinath@linaro.org>
In-Reply-To: <20201219033027.3066042-1-thara.gopinath@linaro.org>
References: <20201219033027.3066042-1-thara.gopinath@linaro.org>
MIME-Version: 1.0
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Export and import interfaces save and restore partial transformation
states. The partial states were being stored and restored in struct
sha1_state for sha1/hmac(sha1) transformations and sha256_state for
sha256/hmac(sha256) transformations.This led to a bunch of corner cases
where improper state was being stored and restored. A few of the corner
cases that turned up during testing are:

- wrong byte_count restored if export/import is called twice without h/w
transaction in between
- wrong buflen restored back if the pending buffer
length is exactly the block size.
- wrong state restored if buffer length is 0.

To fix these issues, save and restore the entire qce_sha_rctx structure
instead of parts of it in sha1_state and sha256_state structures.
This in turn simplifies the export and import apis.

Signed-off-by: Thara Gopinath <thara.gopinath@linaro.org>
---
 drivers/crypto/qce/sha.c | 93 ++++------------------------------------
 1 file changed, 8 insertions(+), 85 deletions(-)

diff --git a/drivers/crypto/qce/sha.c b/drivers/crypto/qce/sha.c
index 61c418c12345..b8428da6716d 100644
--- a/drivers/crypto/qce/sha.c
+++ b/drivers/crypto/qce/sha.c
@@ -139,97 +139,20 @@ static int qce_ahash_init(struct ahash_request *req)
 
 static int qce_ahash_export(struct ahash_request *req, void *out)
 {
-	struct crypto_ahash *ahash = crypto_ahash_reqtfm(req);
-	struct qce_sha_reqctx *rctx = ahash_request_ctx(req);
-	unsigned long flags = rctx->flags;
-	unsigned int digestsize = crypto_ahash_digestsize(ahash);
-	unsigned int blocksize =
-			crypto_tfm_alg_blocksize(crypto_ahash_tfm(ahash));
-
-	if (IS_SHA1(flags) || IS_SHA1_HMAC(flags)) {
-		struct sha1_state *out_state = out;
-
-		out_state->count = rctx->count;
-		qce_cpu_to_be32p_array((__be32 *)out_state->state,
-				       rctx->digest, digestsize);
-		memcpy(out_state->buffer, rctx->buf, blocksize);
-	} else if (IS_SHA256(flags) || IS_SHA256_HMAC(flags)) {
-		struct sha256_state *out_state = out;
-
-		out_state->count = rctx->count;
-		qce_cpu_to_be32p_array((__be32 *)out_state->state,
-				       rctx->digest, digestsize);
-		memcpy(out_state->buf, rctx->buf, blocksize);
-	} else {
-		return -EINVAL;
-	}
-
-	return 0;
-}
-
-static int qce_import_common(struct ahash_request *req, u64 in_count,
-			     const u32 *state, const u8 *buffer, bool hmac)
-{
-	struct crypto_ahash *ahash = crypto_ahash_reqtfm(req);
 	struct qce_sha_reqctx *rctx = ahash_request_ctx(req);
-	unsigned int digestsize = crypto_ahash_digestsize(ahash);
-	unsigned int blocksize;
-	u64 count = in_count;
-
-	blocksize = crypto_tfm_alg_blocksize(crypto_ahash_tfm(ahash));
-	rctx->count = in_count;
-	memcpy(rctx->buf, buffer, blocksize);
-
-	if (in_count <= blocksize) {
-		rctx->first_blk = 1;
-	} else {
-		rctx->first_blk = 0;
-		/*
-		 * For HMAC, there is a hardware padding done when first block
-		 * is set. Therefore the byte_count must be incremened by 64
-		 * after the first block operation.
-		 */
-		if (hmac)
-			count += SHA_PADDING;
-	}
 
-	rctx->byte_count[0] = (__force __be32)(count & ~SHA_PADDING_MASK);
-	rctx->byte_count[1] = (__force __be32)(count >> 32);
-	qce_cpu_to_be32p_array((__be32 *)rctx->digest, (const u8 *)state,
-			       digestsize);
-	rctx->buflen = (unsigned int)(in_count & (blocksize - 1));
+	memcpy(out, rctx, sizeof(struct qce_sha_reqctx));
 
 	return 0;
 }
 
 static int qce_ahash_import(struct ahash_request *req, const void *in)
 {
-	struct qce_sha_reqctx *rctx;
-	unsigned long flags;
-	bool hmac;
-	int ret;
-
-	ret = qce_ahash_init(req);
-	if (ret)
-		return ret;
-
-	rctx = ahash_request_ctx(req);
-	flags = rctx->flags;
-	hmac = IS_SHA_HMAC(flags);
-
-	if (IS_SHA1(flags) || IS_SHA1_HMAC(flags)) {
-		const struct sha1_state *state = in;
+	struct qce_sha_reqctx *rctx = ahash_request_ctx(req);
 
-		ret = qce_import_common(req, state->count, state->state,
-					state->buffer, hmac);
-	} else if (IS_SHA256(flags) || IS_SHA256_HMAC(flags)) {
-		const struct sha256_state *state = in;
+	memcpy(rctx, in, sizeof(struct qce_sha_reqctx));
 
-		ret = qce_import_common(req, state->count, state->state,
-					state->buf, hmac);
-	}
-
-	return ret;
+	return 0;
 }
 
 static int qce_ahash_update(struct ahash_request *req)
@@ -450,7 +373,7 @@ static const struct qce_ahash_def ahash_def[] = {
 		.drv_name	= "sha1-qce",
 		.digestsize	= SHA1_DIGEST_SIZE,
 		.blocksize	= SHA1_BLOCK_SIZE,
-		.statesize	= sizeof(struct sha1_state),
+		.statesize	= sizeof(struct qce_sha_reqctx),
 		.std_iv		= std_iv_sha1,
 	},
 	{
@@ -459,7 +382,7 @@ static const struct qce_ahash_def ahash_def[] = {
 		.drv_name	= "sha256-qce",
 		.digestsize	= SHA256_DIGEST_SIZE,
 		.blocksize	= SHA256_BLOCK_SIZE,
-		.statesize	= sizeof(struct sha256_state),
+		.statesize	= sizeof(struct qce_sha_reqctx),
 		.std_iv		= std_iv_sha256,
 	},
 	{
@@ -468,7 +391,7 @@ static const struct qce_ahash_def ahash_def[] = {
 		.drv_name	= "hmac-sha1-qce",
 		.digestsize	= SHA1_DIGEST_SIZE,
 		.blocksize	= SHA1_BLOCK_SIZE,
-		.statesize	= sizeof(struct sha1_state),
+		.statesize	= sizeof(struct qce_sha_reqctx),
 		.std_iv		= std_iv_sha1,
 	},
 	{
@@ -477,7 +400,7 @@ static const struct qce_ahash_def ahash_def[] = {
 		.drv_name	= "hmac-sha256-qce",
 		.digestsize	= SHA256_DIGEST_SIZE,
 		.blocksize	= SHA256_BLOCK_SIZE,
-		.statesize	= sizeof(struct sha256_state),
+		.statesize	= sizeof(struct qce_sha_reqctx),
 		.std_iv		= std_iv_sha256,
 	},
 };
-- 
2.25.1