[PATCH AUTOSEL 4.4 29/48] crypto: mxs-dcp - Fix SHA null hashes and output length

[PATCH AUTOSEL 4.4 29/48] crypto: mxs-dcp - Fix SHA null hashes and output length

[Sasha Levin]

From: Radu Solea <radu.solea@nxp.com>

[ Upstream commit c709eebaf5c5faa8a0f140355f9cfe67e8f7afb1 ]

DCP writes at least 32 bytes in the output buffer instead of hash length
as documented. Add intermediate buffer to prevent write out of bounds.

When requested to produce null hashes DCP fails to produce valid output.
Add software workaround to bypass hardware and return valid output.

Signed-off-by: Radu Solea <radu.solea@nxp.com>
Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/crypto/mxs-dcp.c | 47 +++++++++++++++++++++++++++++++---------
 1 file changed, 37 insertions(+), 10 deletions(-)

diff --git a/drivers/crypto/mxs-dcp.c b/drivers/crypto/mxs-dcp.c
index fe8cfe24c518f..38c5dd8891138 100644
--- a/drivers/crypto/mxs-dcp.c
+++ b/drivers/crypto/mxs-dcp.c
@@ -28,9 +28,24 @@
 
 #define DCP_MAX_CHANS	4
 #define DCP_BUF_SZ	PAGE_SIZE
+#define DCP_SHA_PAY_SZ  64
 
 #define DCP_ALIGNMENT	64
 
+/*
+ * Null hashes to align with hw behavior on imx6sl and ull
+ * these are flipped for consistency with hw output
+ */
+const uint8_t sha1_null_hash[] =
+	"\x09\x07\xd8\xaf\x90\x18\x60\x95\xef\xbf"
+	"\x55\x32\x0d\x4b\x6b\x5e\xee\xa3\x39\xda";
+
+const uint8_t sha256_null_hash[] =
+	"\x55\xb8\x52\x78\x1b\x99\x95\xa4"
+	"\x4c\x93\x9b\x64\xe4\x41\xae\x27"
+	"\x24\xb9\x6f\x99\xc8\xf4\xfb\x9a"
+	"\x14\x1c\xfc\x98\x42\xc4\xb0\xe3";
+
 /* DCP DMA descriptor. */
 struct dcp_dma_desc {
 	uint32_t	next_cmd_addr;
@@ -48,6 +63,7 @@ struct dcp_coherent_block {
 	uint8_t			aes_in_buf[DCP_BUF_SZ];
 	uint8_t			aes_out_buf[DCP_BUF_SZ];
 	uint8_t			sha_in_buf[DCP_BUF_SZ];
+	uint8_t			sha_out_buf[DCP_SHA_PAY_SZ];
 
 	uint8_t			aes_key[2 * AES_KEYSIZE_128];
 
@@ -518,8 +534,6 @@ static int mxs_dcp_run_sha(struct ahash_request *req)
 	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
 	struct dcp_async_ctx *actx = crypto_ahash_ctx(tfm);
 	struct dcp_sha_req_ctx *rctx = ahash_request_ctx(req);
-	struct hash_alg_common *halg = crypto_hash_alg_common(tfm);
-
 	struct dcp_dma_desc *desc = &sdcp->coh->desc[actx->chan];
 
 	dma_addr_t digest_phys = 0;
@@ -541,10 +555,23 @@ static int mxs_dcp_run_sha(struct ahash_request *req)
 	desc->payload = 0;
 	desc->status = 0;
 
+	/*
+	 * Align driver with hw behavior when generating null hashes
+	 */
+	if (rctx->init && rctx->fini && desc->size == 0) {
+		struct hash_alg_common *halg = crypto_hash_alg_common(tfm);
+		const uint8_t *sha_buf =
+			(actx->alg == MXS_DCP_CONTROL1_HASH_SELECT_SHA1) ?
+			sha1_null_hash : sha256_null_hash;
+		memcpy(sdcp->coh->sha_out_buf, sha_buf, halg->digestsize);
+		ret = 0;
+		goto done_run;
+	}
+
 	/* Set HASH_TERM bit for last transfer block. */
 	if (rctx->fini) {
-		digest_phys = dma_map_single(sdcp->dev, req->result,
-					     halg->digestsize, DMA_FROM_DEVICE);
+		digest_phys = dma_map_single(sdcp->dev, sdcp->coh->sha_out_buf,
+					     DCP_SHA_PAY_SZ, DMA_FROM_DEVICE);
 		desc->control0 |= MXS_DCP_CONTROL0_HASH_TERM;
 		desc->payload = digest_phys;
 	}
@@ -552,9 +579,10 @@ static int mxs_dcp_run_sha(struct ahash_request *req)
 	ret = mxs_dcp_start_dma(actx);
 
 	if (rctx->fini)
-		dma_unmap_single(sdcp->dev, digest_phys, halg->digestsize,
+		dma_unmap_single(sdcp->dev, digest_phys, DCP_SHA_PAY_SZ,
 				 DMA_FROM_DEVICE);
 
+done_run:
 	dma_unmap_single(sdcp->dev, buf_phys, DCP_BUF_SZ, DMA_TO_DEVICE);
 
 	return ret;
@@ -572,6 +600,7 @@ static int dcp_sha_req_to_buf(struct crypto_async_request *arq)
 	const int nents = sg_nents(req->src);
 
 	uint8_t *in_buf = sdcp->coh->sha_in_buf;
+	uint8_t *out_buf = sdcp->coh->sha_out_buf;
 
 	uint8_t *src_buf;
 
@@ -626,11 +655,9 @@ static int dcp_sha_req_to_buf(struct crypto_async_request *arq)
 
 		actx->fill = 0;
 
-		/* For some reason, the result is flipped. */
-		for (i = 0; i < halg->digestsize / 2; i++) {
-			swap(req->result[i],
-			     req->result[halg->digestsize - i - 1]);
-		}
+		/* For some reason the result is flipped */
+		for (i = 0; i < halg->digestsize; i++)
+			req->result[i] = out_buf[halg->digestsize - i - 1];
 	}
 
 	return 0;
-- 
2.20.1

[PATCH AUTOSEL 4.4 30/48] crypto: mxs-dcp - Fix AES issues

[Sasha Levin]

From: Radu Solea <radu.solea@nxp.com>

[ Upstream commit fadd7a6e616b89c7f4f7bfa7b824f290bab32c3c ]

The DCP driver does not obey cryptlen, when doing android CTS this
results in passing to hardware input stream lengths which are not
multiple of block size.

Add a check to prevent future erroneous stream lengths from reaching the
hardware and adjust the scatterlist walking code to obey cryptlen.

Also properly copy-out the IV for chaining.

Signed-off-by: Radu Solea <radu.solea@nxp.com>
Signed-off-by: Franck LENORMAND <franck.lenormand@nxp.com>
Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/crypto/mxs-dcp.c | 33 +++++++++++++++++++++++++++++++--
 1 file changed, 31 insertions(+), 2 deletions(-)

diff --git a/drivers/crypto/mxs-dcp.c b/drivers/crypto/mxs-dcp.c
index 38c5dd8891138..4b82cf9da0ba7 100644
--- a/drivers/crypto/mxs-dcp.c
+++ b/drivers/crypto/mxs-dcp.c
@@ -225,6 +225,12 @@ static int mxs_dcp_run_aes(struct dcp_async_ctx *actx,
 	dma_addr_t dst_phys = dma_map_single(sdcp->dev, sdcp->coh->aes_out_buf,
 					     DCP_BUF_SZ, DMA_FROM_DEVICE);
 
+	if (actx->fill % AES_BLOCK_SIZE) {
+		dev_err(sdcp->dev, "Invalid block size!\n");
+		ret = -EINVAL;
+		goto aes_done_run;
+	}
+
 	/* Fill in the DMA descriptor. */
 	desc->control0 = MXS_DCP_CONTROL0_DECR_SEMAPHORE |
 		    MXS_DCP_CONTROL0_INTERRUPT |
@@ -254,6 +260,7 @@ static int mxs_dcp_run_aes(struct dcp_async_ctx *actx,
 
 	ret = mxs_dcp_start_dma(actx);
 
+aes_done_run:
 	dma_unmap_single(sdcp->dev, key_phys, 2 * AES_KEYSIZE_128,
 			 DMA_TO_DEVICE);
 	dma_unmap_single(sdcp->dev, src_phys, DCP_BUF_SZ, DMA_TO_DEVICE);
@@ -280,13 +287,15 @@ static int mxs_dcp_aes_block_crypt(struct crypto_async_request *arq)
 
 	uint8_t *out_tmp, *src_buf, *dst_buf = NULL;
 	uint32_t dst_off = 0;
+	uint32_t last_out_len = 0;
 
 	uint8_t *key = sdcp->coh->aes_key;
 
 	int ret = 0;
 	int split = 0;
-	unsigned int i, len, clen, rem = 0;
+	unsigned int i, len, clen, rem = 0, tlen = 0;
 	int init = 0;
+	bool limit_hit = false;
 
 	actx->fill = 0;
 
@@ -305,6 +314,11 @@ static int mxs_dcp_aes_block_crypt(struct crypto_async_request *arq)
 	for_each_sg(req->src, src, nents, i) {
 		src_buf = sg_virt(src);
 		len = sg_dma_len(src);
+		tlen += len;
+		limit_hit = tlen > req->nbytes;
+
+		if (limit_hit)
+			len = req->nbytes - (tlen - len);
 
 		do {
 			if (actx->fill + len > out_off)
@@ -321,13 +335,15 @@ static int mxs_dcp_aes_block_crypt(struct crypto_async_request *arq)
 			 * If we filled the buffer or this is the last SG,
 			 * submit the buffer.
 			 */
-			if (actx->fill == out_off || sg_is_last(src)) {
+			if (actx->fill == out_off || sg_is_last(src) ||
+				limit_hit) {
 				ret = mxs_dcp_run_aes(actx, req, init);
 				if (ret)
 					return ret;
 				init = 0;
 
 				out_tmp = out_buf;
+				last_out_len = actx->fill;
 				while (dst && actx->fill) {
 					if (!split) {
 						dst_buf = sg_virt(dst);
@@ -350,6 +366,19 @@ static int mxs_dcp_aes_block_crypt(struct crypto_async_request *arq)
 				}
 			}
 		} while (len);
+
+		if (limit_hit)
+			break;
+	}
+
+	/* Copy the IV for CBC for chaining */
+	if (!rctx->ecb) {
+		if (rctx->enc)
+			memcpy(req->info, out_buf+(last_out_len-AES_BLOCK_SIZE),
+				AES_BLOCK_SIZE);
+		else
+			memcpy(req->info, in_buf+(last_out_len-AES_BLOCK_SIZE),
+				AES_BLOCK_SIZE);
 	}
 
 	return ret;
-- 
2.20.1