rsa: cosmetic: rename pad_len to key_len

checksum_algo's pad_len field isn't actually used to store the length of
the padding but the total length of the RSA key (msg_len + pad_len)

Signed-off-by: Andrew Duda <aduda@meraki.com>
Signed-off-by: aduda <aduda@meraki.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

include/image.h

@@ -1070,7 +1070,7 @@ struct image_region {
 struct checksum_algo {
 	const char *name;
 	const int checksum_len;
-	const int pad_len;
+	const int key_len;
 #if IMAGE_ENABLE_SIGN
 	const EVP_MD *(*calculate_sign)(void);
 #endif

lib/rsa/rsa-verify.c

@@ -84,7 +84,7 @@ static int rsa_verify_key(struct key_prop *prop, const uint8_t *sig,
 	}
 
 	padding = algo->rsa_padding;
-	pad_len = algo->pad_len - algo->checksum_len;
+	pad_len = algo->key_len - algo->checksum_len;
 
 	/* Check pkcs1.5 padding bytes. */
 	if (memcmp(buf, padding, pad_len)) {
@@ -160,7 +160,7 @@ int rsa_verify(struct image_sign_info *info,
 {
 	const void *blob = info->fdt_blob;
 	/* Reserve memory for maximum checksum-length */
-	uint8_t hash[info->algo->checksum->pad_len];
+	uint8_t hash[info->algo->checksum->key_len];
 	int ndepth, noffset;
 	int sig_node, node;
 	char name[100];
@@ -171,7 +171,7 @@ int rsa_verify(struct image_sign_info *info,
 	 * rsa-signature-length
 	 */
 	if (info->algo->checksum->checksum_len >
-	    info->algo->checksum->pad_len) {
+	    info->algo->checksum->key_len) {
 		debug("%s: invlaid checksum-algorithm %s for %s\n",
 		      __func__, info->algo->checksum->name, info->algo->name);
 		return -EINVAL;