crypto: caam - generate hash keys in-place

When generating a split key or hashing the key, DMA mapping the key
buffers coming directly from user is incorrect, since they are
not guaranteed to be DMAable.

Update driver to first copy user-provided key in the output buffer
("key_out") and then use this buffer for in-place computation
(split key generation, respectively key hashing).
Signed-off-by: Horia Geantă <horia.geanta@nxp.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/crypto/caam/caamhash.c

@@ -395,13 +395,13 @@ static int acmac_set_sh_desc(struct crypto_ahash *ahash)
 }
 
 /* Digest hash size if it is too large */
-static int hash_digest_key(struct caam_hash_ctx *ctx, const u8 *key_in,
-			   u32 *keylen, u8 *key_out, u32 digestsize)
+static int hash_digest_key(struct caam_hash_ctx *ctx, u32 *keylen, u8 *key,
+			   u32 digestsize)
 {
 	struct device *jrdev = ctx->jrdev;
 	u32 *desc;
 	struct split_key_result result;
-	dma_addr_t src_dma, dst_dma;
+	dma_addr_t key_dma;
 	int ret;
 
 	desc = kmalloc(CAAM_CMD_SZ * 8 + CAAM_PTR_SZ * 2, GFP_KERNEL | GFP_DMA);
@@ -412,18 +412,9 @@ static int hash_digest_key(struct caam_hash_ctx *ctx, const u8 *key_in,
 
 	init_job_desc(desc, 0);
 
-	src_dma = dma_map_single(jrdev, (void *)key_in, *keylen,
-				 DMA_TO_DEVICE);
-	if (dma_mapping_error(jrdev, src_dma)) {
-		dev_err(jrdev, "unable to map key input memory\n");
-		kfree(desc);
-		return -ENOMEM;
-	}
-	dst_dma = dma_map_single(jrdev, (void *)key_out, digestsize,
-				 DMA_FROM_DEVICE);
-	if (dma_mapping_error(jrdev, dst_dma)) {
-		dev_err(jrdev, "unable to map key output memory\n");
-		dma_unmap_single(jrdev, src_dma, *keylen, DMA_TO_DEVICE);
+	key_dma = dma_map_single(jrdev, key, *keylen, DMA_BIDIRECTIONAL);
+	if (dma_mapping_error(jrdev, key_dma)) {
+		dev_err(jrdev, "unable to map key memory\n");
 		kfree(desc);
 		return -ENOMEM;
 	}
@@ -431,16 +422,16 @@ static int hash_digest_key(struct caam_hash_ctx *ctx, const u8 *key_in,
 	/* Job descriptor to perform unkeyed hash on key_in */
 	append_operation(desc, ctx->adata.algtype | OP_ALG_ENCRYPT |
 			 OP_ALG_AS_INITFINAL);
-	append_seq_in_ptr(desc, src_dma, *keylen, 0);
+	append_seq_in_ptr(desc, key_dma, *keylen, 0);
 	append_seq_fifo_load(desc, *keylen, FIFOLD_CLASS_CLASS2 |
 			     FIFOLD_TYPE_LAST2 | FIFOLD_TYPE_MSG);
-	append_seq_out_ptr(desc, dst_dma, digestsize, 0);
+	append_seq_out_ptr(desc, key_dma, digestsize, 0);
 	append_seq_store(desc, digestsize, LDST_CLASS_2_CCB |
 			 LDST_SRCDST_BYTE_CONTEXT);
 
 #ifdef DEBUG
 	print_hex_dump(KERN_ERR, "key_in@"__stringify(__LINE__)": ",
-		       DUMP_PREFIX_ADDRESS, 16, 4, key_in, *keylen, 1);
+		       DUMP_PREFIX_ADDRESS, 16, 4, key, *keylen, 1);
 	print_hex_dump(KERN_ERR, "jobdesc@"__stringify(__LINE__)": ",
 		       DUMP_PREFIX_ADDRESS, 16, 4, desc, desc_bytes(desc), 1);
 #endif
@@ -456,12 +447,10 @@ static int hash_digest_key(struct caam_hash_ctx *ctx, const u8 *key_in,
 #ifdef DEBUG
 		print_hex_dump(KERN_ERR,
 			       "digested key@"__stringify(__LINE__)": ",
-			       DUMP_PREFIX_ADDRESS, 16, 4, key_in,
-			       digestsize, 1);
+			       DUMP_PREFIX_ADDRESS, 16, 4, key, digestsize, 1);
 #endif
 	}
-	dma_unmap_single(jrdev, src_dma, *keylen, DMA_TO_DEVICE);
-	dma_unmap_single(jrdev, dst_dma, digestsize, DMA_FROM_DEVICE);
+	dma_unmap_single(jrdev, key_dma, *keylen, DMA_BIDIRECTIONAL);
 
 	*keylen = digestsize;
 
@@ -485,13 +474,10 @@ static int ahash_setkey(struct crypto_ahash *ahash,
 #endif
 
 	if (keylen > blocksize) {
-		hashed_key = kmalloc_array(digestsize,
-					   sizeof(*hashed_key),
-					   GFP_KERNEL | GFP_DMA);
+		hashed_key = kmemdup(key, keylen, GFP_KERNEL | GFP_DMA);
 		if (!hashed_key)
 			return -ENOMEM;
-		ret = hash_digest_key(ctx, key, &keylen, hashed_key,
-				      digestsize);
+		ret = hash_digest_key(ctx, &keylen, hashed_key, digestsize);
 		if (ret)
 			goto bad_free_key;
 		key = hashed_key;

drivers/crypto/caam/key_gen.c

@@ -48,7 +48,7 @@ int gen_split_key(struct device *jrdev, u8 *key_out,
 {
 	u32 *desc;
 	struct split_key_result result;
-	dma_addr_t dma_addr_in, dma_addr_out;
+	dma_addr_t dma_addr;
 	int ret = -ENOMEM;
 
 	adata->keylen = split_key_len(adata->algtype & OP_ALG_ALGSEL_MASK);
@@ -71,22 +71,17 @@ int gen_split_key(struct device *jrdev, u8 *key_out,
 		return ret;
 	}
 
-	dma_addr_in = dma_map_single(jrdev, (void *)key_in, keylen,
-				     DMA_TO_DEVICE);
-	if (dma_mapping_error(jrdev, dma_addr_in)) {
-		dev_err(jrdev, "unable to map key input memory\n");
-		goto out_free;
-	}
+	memcpy(key_out, key_in, keylen);
 
-	dma_addr_out = dma_map_single(jrdev, key_out, adata->keylen_pad,
-				      DMA_FROM_DEVICE);
-	if (dma_mapping_error(jrdev, dma_addr_out)) {
-		dev_err(jrdev, "unable to map key output memory\n");
-		goto out_unmap_in;
+	dma_addr = dma_map_single(jrdev, key_out, adata->keylen_pad,
+				  DMA_BIDIRECTIONAL);
+	if (dma_mapping_error(jrdev, dma_addr)) {
+		dev_err(jrdev, "unable to map key memory\n");
+		goto out_free;
 	}
 
 	init_job_desc(desc, 0);
-	append_key(desc, dma_addr_in, keylen, CLASS_2 | KEY_DEST_CLASS_REG);
+	append_key(desc, dma_addr, keylen, CLASS_2 | KEY_DEST_CLASS_REG);
 
 	/* Sets MDHA up into an HMAC-INIT */
 	append_operation(desc, (adata->algtype & OP_ALG_ALGSEL_MASK) |
@@ -104,12 +99,10 @@ int gen_split_key(struct device *jrdev, u8 *key_out,
 	 * FIFO_STORE with the explicit split-key content store
 	 * (0x26 output type)
 	 */
-	append_fifo_store(desc, dma_addr_out, adata->keylen,
+	append_fifo_store(desc, dma_addr, adata->keylen,
 			  LDST_CLASS_2_CCB | FIFOST_TYPE_SPLIT_KEK);
 
 #ifdef DEBUG
-	print_hex_dump(KERN_ERR, "ctx.key@"__stringify(__LINE__)": ",
-		       DUMP_PREFIX_ADDRESS, 16, 4, key_in, keylen, 1);
 	print_hex_dump(KERN_ERR, "jobdesc@"__stringify(__LINE__)": ",
 		       DUMP_PREFIX_ADDRESS, 16, 4, desc, desc_bytes(desc), 1);
 #endif
@@ -129,10 +122,7 @@ int gen_split_key(struct device *jrdev, u8 *key_out,
 #endif
 	}
 
-	dma_unmap_single(jrdev, dma_addr_out, adata->keylen_pad,
-			 DMA_FROM_DEVICE);
-out_unmap_in:
-	dma_unmap_single(jrdev, dma_addr_in, keylen, DMA_TO_DEVICE);
+	dma_unmap_single(jrdev, dma_addr, adata->keylen_pad, DMA_BIDIRECTIONAL);
 out_free:
 	kfree(desc);
 	return ret;