@@ -176,6 +176,7 @@ int dlp_is_valid_cc(const unsigned char *buffer, size_t length)

     int mult   = 0;

     int sum    = 0;

     size_t i   = 0;

+    ssize_t j  = 0;

     int val    = 0;

     int digits = 0;

     char cc_digits[20];

@@ -232,9 +233,11 @@ int dlp_is_valid_cc(const unsigned char *buffer, size_t length)

     if (digits < 13 || (i < length && isdigit(buffer[i])))

         return 0;

+    j = (ssize_t)i;

+

     //figure out luhn digits

-    for (i = digits - 1; i >= 0; i--) {

-        val = cc_digits[i] - '0';

+    for (j = digits - 1; j >= 0; j--) {

+        val = cc_digits[j] - '0';

         if (mult) {

             if ((val *= 2) > 9) val -= 9;

         }