core: improve header safe guards for Via handling

(cherry picked from commit ad68e40)

src/core/crc.c

@@ -231,6 +231,8 @@ void crcitt_string_array( char *dst, str src[], int size )
 	ccitt = 0xFFFF;
 	str_len=CRC16_LEN;
 	for (i=0; i<size; i++ ) {
+		/* invalid str with positive length and null char pointer */
+		if( unlikely(src[i].s==NULL)) break;
 		c=src[i].s;
 		len=src[i].len;
 		while(len) {

src/core/msg_translator.c

@@ -168,12 +168,17 @@ static int check_via_address(struct ip_addr* ip, str *name,
 						(name->s[name->len-1]==']')&&
 						(strncasecmp(name->s+1, s, len)==0))
 				)
-		   )
+		   ) {
 			return 0;
-		else
-
+		}
+		else {
+			if (unlikely(name->s==NULL)) {
+				LM_CRIT("invalid Via host name\n");
+				return -1;
+			}
 			if (strncmp(name->s, s, name->len)==0)
 				return 0;
+		}
 	}else{
 		LM_CRIT("could not convert ip address\n");
 		return -1;