Eliminate duplicate ct memcmp

Signed-off-by: Dave Rodgman <dave.rodgman@arm.com>
This commit is contained in:
Dave Rodgman 2023-09-11 18:25:16 +01:00
parent 8a7fb2d799
commit d26a3d6da7
3 changed files with 6 additions and 14 deletions

View file

@ -33,6 +33,7 @@
#include "mbedtls/ccm.h"
#include "mbedtls/platform_util.h"
#include "mbedtls/error.h"
#include "mbedtls/constant_time.h"
#include <string.h>
@ -533,13 +534,8 @@ static int mbedtls_ccm_compare_tags(const unsigned char *tag1,
const unsigned char *tag2,
size_t tag_len)
{
unsigned char i;
int diff;
/* Check tag in "constant-time" */
for (diff = 0, i = 0; i < tag_len; i++) {
diff |= tag1[i] ^ tag2[i];
}
int diff = mbedtls_ct_memcmp(tag1, tag2, tag_len);
if (diff != 0) {
return MBEDTLS_ERR_CCM_AUTH_FAILED;