Harden hash comparison in TLS1.2 finished

Author: Frauschi

src/internal.c

@@ -17611,7 +17611,8 @@ int DoFinished(WOLFSSL* ssl, const byte* input, word32* inOutIdx, word32 size,
     #endif
 
     if (sniff == NO_SNIFF) {
-        if (XMEMCMP(input + *inOutIdx, &ssl->hsHashes->verifyHashes,size) != 0){
+        if (ConstantCompare(input + *inOutIdx,
+                   (const byte*)&ssl->hsHashes->verifyHashes, (int)size) != 0) {
             WOLFSSL_MSG("Verify finished error on hashes");
             WOLFSSL_ERROR_VERBOSE(VERIFY_FINISHED_ERROR);
             return VERIFY_FINISHED_ERROR;