[U-Boot] [PATCH 10/10][v6] rsa: Use checksum algorithms from struct hash_algo

[Ruchika Gupta]

Currently the hash functions used in RSA are called directly from the sha1
and sha256 libraries. Change the RSA checksum library to use the progressive
hash API's registered with struct hash_algo. This will allow the checksum
library to use the hardware accelerated progressive hash API's once available.

Signed-off-by: Ruchika Gupta <ruchika.gupta at freescale.com>
CC: Simon Glass <sjg at chromium.org>
---
Changes in v6:
Removed changes in ls1021aqds.h accidently included in this patch

Changes in v5:
Both tools and uboot use the same code in rsa-checksum.c

Changes in v4:
No changes in this patch. Still under discussion

Changes in v3:
Modified rsa-verify to check for return from checksum function

Changes in v2:
Added generic function hash_calculate. Pass an additional
argument as name of algorithm. 

 common/image-sig.c            |  6 +++---
 include/image.h               |  5 +++--
 include/u-boot/rsa-checksum.h | 17 +++++++++++----
 lib/rsa/rsa-checksum.c        | 50 ++++++++++++++++++++++++++-----------------
 lib/rsa/rsa-verify.c          |  7 +++++-
 5 files changed, 55 insertions(+), 30 deletions(-)

diff --git a/common/image-sig.c b/common/image-sig.c
index 8601eda..2c9f0cd 100644
--- a/common/image-sig.c
+++ b/common/image-sig.c
@@ -38,7 +38,7 @@ struct checksum_algo checksum_algos[] = {
 #if IMAGE_ENABLE_SIGN
 		EVP_sha1,
 #endif
-		sha1_calculate,
+		hash_calculate,
 		padding_sha1_rsa2048,
 	},
 	{
@@ -48,7 +48,7 @@ struct checksum_algo checksum_algos[] = {
 #if IMAGE_ENABLE_SIGN
 		EVP_sha256,
 #endif
-		sha256_calculate,
+		hash_calculate,
 		padding_sha256_rsa2048,
 	},
 	{
@@ -58,7 +58,7 @@ struct checksum_algo checksum_algos[] = {
 #if IMAGE_ENABLE_SIGN
 		EVP_sha256,
 #endif
-		sha256_calculate,
+		hash_calculate,
 		padding_sha256_rsa4096,
 	}
 
diff --git a/include/image.h b/include/image.h
index ee3afe3..dcbc72f 100644
--- a/include/image.h
+++ b/include/image.h
@@ -927,8 +927,9 @@ struct checksum_algo {
 #if IMAGE_ENABLE_SIGN
 	const EVP_MD *(*calculate_sign)(void);
 #endif
-	void (*calculate)(const struct image_region region[],
-			  int region_count, uint8_t *checksum);
+	int (*calculate)(const char *name,
+			 const struct image_region region[],
+			 int region_count, uint8_t *checksum);
 	const uint8_t *rsa_padding;
 };
 
diff --git a/include/u-boot/rsa-checksum.h b/include/u-boot/rsa-checksum.h
index c996fb3..3c69d85 100644
--- a/include/u-boot/rsa-checksum.h
+++ b/include/u-boot/rsa-checksum.h
@@ -16,9 +16,18 @@ extern const uint8_t padding_sha256_rsa4096[];
 extern const uint8_t padding_sha256_rsa2048[];
 extern const uint8_t padding_sha1_rsa2048[];
 
-void sha256_calculate(const struct image_region region[], int region_count,
-		      uint8_t *checksum);
-void sha1_calculate(const struct image_region region[], int region_count,
-		    uint8_t *checksum);
+/**
+ * hash_calculate() - Calculate hash over the data
+ *
+ * @name:  Name of algorithm to be used for hash calculation
+ * @region: Array having info of regions over which hash needs to be calculated
+ * @region_count: Number of regions in the region array
+ * @checksum: Buffer contanining the output hash
+ *
+ * @return 0 if OK, < 0 if error
+ */
+int hash_calculate(const char *name,
+		   const struct image_region region[], int region_count,
+		   uint8_t *checksum);
 
 #endif
diff --git a/lib/rsa/rsa-checksum.c b/lib/rsa/rsa-checksum.c
index 8d8b59f..68d9d65 100644
--- a/lib/rsa/rsa-checksum.c
+++ b/lib/rsa/rsa-checksum.c
@@ -10,12 +10,13 @@
 #include <asm/byteorder.h>
 #include <asm/errno.h>
 #include <asm/unaligned.h>
+#include <hash.h>
 #else
 #include "fdt_host.h"
-#endif
-#include <u-boot/rsa.h>
 #include <u-boot/sha1.h>
 #include <u-boot/sha256.h>
+#endif
+#include <u-boot/rsa.h>
 
 /* PKCS 1.5 paddings as described in the RSA PKCS#1 v2.1 standard. */
 
@@ -136,28 +137,37 @@ const uint8_t padding_sha256_rsa4096[RSA4096_BYTES - SHA256_SUM_LEN] = {
 	0x03, 0x04, 0x02, 0x01, 0x05, 0x00, 0x04, 0x20
 };
 
-void sha1_calculate(const struct image_region region[], int region_count,
-		    uint8_t *checksum)
+int hash_calculate(const char *name,
+		    const struct image_region region[],
+		    int region_count, uint8_t *checksum)
 {
-	sha1_context ctx;
+	struct hash_algo *algo;
+	int ret = 0;
+	void *ctx;
 	uint32_t i;
 	i = 0;
 
-	sha1_starts(&ctx);
-	for (i = 0; i < region_count; i++)
-		sha1_update(&ctx, region[i].data, region[i].size);
-	sha1_finish(&ctx, checksum);
-}
+	ret = hash_progressive_lookup_algo(name, &algo);
+	if (ret)
+		return ret;
 
-void sha256_calculate(const struct image_region region[], int region_count,
-		      uint8_t *checksum)
-{
-	sha256_context ctx;
-	uint32_t i;
-	i = 0;
+	ret = algo->hash_init(algo, &ctx);
+	if (ret)
+		return ret;
+
+	for (i = 0; i < region_count - 1; i++) {
+		ret = algo->hash_update(algo, ctx, region[i].data,
+					region[i].size, 0);
+		if (ret)
+			return ret;
+	}
+
+	ret = algo->hash_update(algo, ctx, region[i].data, region[i].size, 1);
+	if (ret)
+		return ret;
+	ret = algo->hash_finish(algo, ctx, checksum, algo->digest_size);
+	if (ret)
+		return ret;
 
-	sha256_starts(&ctx);
-	for (i = 0; i < region_count; i++)
-		sha256_update(&ctx, region[i].data, region[i].size);
-	sha256_finish(&ctx, checksum);
+	return 0;
 }
diff --git a/lib/rsa/rsa-verify.c b/lib/rsa/rsa-verify.c
index da45daf..60126d2 100644
--- a/lib/rsa/rsa-verify.c
+++ b/lib/rsa/rsa-verify.c
@@ -184,7 +184,12 @@ int rsa_verify(struct image_sign_info *info,
 	}
 
 	/* Calculate checksum with checksum-algorithm */
-	info->algo->checksum->calculate(region, region_count, hash);
+	ret = info->algo->checksum->calculate(info->algo->checksum->name,
+					region, region_count, hash);
+	if (ret < 0) {
+		debug("%s: Error in checksum calculation\n", __func__);
+		return -EINVAL;
+	}
 
 	/* See if we must use a particular key */
 	if (info->required_keynode != -1) {
-- 
1.8.1.4