Fix GCC warning in `ssl_calc_finished_tls_sha384`
This commit fixes the same warning fixed by but without
wasting RAM. By casting `mbedtls_sha512_finish_ret()`, `padbuf`
could be kept 48 bytes long without triggering any warnings.
@@ -3197,12 +3197,15 @@ static void ssl_calc_finished_tls_sha256(
#endif /* MBEDTLS_SHA256_C */
#if defined(MBEDTLS_SHA512_C)
+
+typedef int (*finish_sha384_t)(mbedtls_sha512_context*, unsigned char[48]);
+
static void ssl_calc_finished_tls_sha384(
mbedtls_ssl_context *ssl, unsigned char *buf, int from )
{
int len = 12;
const char *sender;
- unsigned char padbuf[64];
+ unsigned char padbuf[48];
#if defined(MBEDTLS_USE_PSA_CRYPTO)
size_t hash_size;
psa_hash_operation_t sha384_psa = PSA_HASH_OPERATION_INIT;
@@ -3255,8 +3258,14 @@ static void ssl_calc_finished_tls_sha384(
MBEDTLS_SSL_DEBUG_BUF( 4, "finished sha512 state", (unsigned char *)
sha512.state, sizeof( sha512.state ) );
#endif
+ /*
+ * For SHA-384, we can save 16 bytes by keeping padbuf 48 bytes long.
+ * However, to avoid stringop-overflow warning in gcc, we have to cast
+ * mbedtls_sha512_finish_ret().
+ */
+ finish_sha384_t finish = (finish_sha384_t)mbedtls_sha512_finish_ret;
+ finish( &sha512, padbuf );
- mbedtls_sha512_finish_ret( &sha512, padbuf );
mbedtls_sha512_free( &sha512 );
#endif
