lib: rsa: Fix const-correctness of rsassa_pss functions

Prior to introduction of modifications in rsassa_pss functions
related to padding verification, doing a pass to update
const-correctness in targeted functions to comply with
coding-rules and avoid const-cast

Signed-off-by: SESA644425 <gioja.hermann@non.se.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/include/image.h b/include/image.h
index 673b5f5..e4c6a50 100644
--- a/include/image.h
+++ b/include/image.h
@@ -1309,7 +1309,7 @@
 struct padding_algo {
 	const char *name;
 	int (*verify)(struct image_sign_info *info,
-		      uint8_t *pad, int pad_len,
+		      const uint8_t *pad, int pad_len,
 		      const uint8_t *hash, int hash_len);
 };
 
diff --git a/include/u-boot/rsa.h b/include/u-boot/rsa.h
index b9634e3..085363e 100644
--- a/include/u-boot/rsa.h
+++ b/include/u-boot/rsa.h
@@ -101,11 +101,11 @@
 			 const void *hash, uint8_t *sig, uint sig_len);
 
 int padding_pkcs_15_verify(struct image_sign_info *info,
-			   uint8_t *msg, int msg_len,
+			   const uint8_t *msg, int msg_len,
 			   const uint8_t *hash, int hash_len);
 
 int padding_pss_verify(struct image_sign_info *info,
-		       uint8_t *msg, int msg_len,
+		       const uint8_t *msg, int msg_len,
 		       const uint8_t *hash, int hash_len);
 
 #define RSA_DEFAULT_PADDING_NAME		"pkcs-1.5"
diff --git a/lib/rsa/rsa-verify.c b/lib/rsa/rsa-verify.c
index 1126640..c2c7248 100644
--- a/lib/rsa/rsa-verify.c
+++ b/lib/rsa/rsa-verify.c
@@ -73,7 +73,7 @@
 }
 
 int padding_pkcs_15_verify(struct image_sign_info *info,
-			   uint8_t *msg, int msg_len,
+			   const uint8_t *msg, int msg_len,
 			   const uint8_t *hash, int hash_len)
 {
 	struct checksum_algo *checksum = info->checksum;
@@ -125,7 +125,7 @@
  * Return: 0 if the octet string was correctly generated, others on error
  */
 static int mask_generation_function1(struct checksum_algo *checksum,
-				     uint8_t *seed, int seed_len,
+				     const uint8_t *seed, int seed_len,
 				     uint8_t *output, int output_len)
 {
 	struct image_region region[2];
@@ -176,9 +176,9 @@
 }
 
 static int compute_hash_prime(struct checksum_algo *checksum,
-			      uint8_t *pad, int pad_len,
-			      uint8_t *hash, int hash_len,
-			      uint8_t *salt, int salt_len,
+			      const uint8_t *pad, int pad_len,
+			      const uint8_t *hash, int hash_len,
+			      const uint8_t *salt, int salt_len,
 			      uint8_t *hprime)
 {
 	struct image_region region[3];
@@ -215,7 +215,7 @@
  * @hash_len:	Length of the hash
  */
 int padding_pss_verify(struct image_sign_info *info,
-		       uint8_t *msg, int msg_len,
+		       const uint8_t *msg, int msg_len,
 		       const uint8_t *hash, int hash_len)
 {
 	uint8_t *masked_db = NULL;
@@ -287,7 +287,7 @@
 
 	/* step 12 & 13 */
 	compute_hash_prime(checksum, pad_zero, 8,
-			   (uint8_t *)hash, hash_len,
+			   hash, hash_len,
 			   salt, salt_len, hprime);
 
 	/* step 14 */