FileZilla Password Decrypter

fzdecrypt.c

#include <stdio.h>

const char fzKey[] = "FILEZILLA1234567890ABCDEFGHIJKLMNOPQRSTUVWXYZ";
const int fzKeyLen = 45;

char *decrypt(const char *str, char *targetStr) {
  int i = 0, oriLen = 0, pos;
  if (!str || !targetStr) return 0;
  *targetStr = 0;
  for (; str[oriLen]; ++oriLen)
    ;
  if (oriLen % 3) return 0;
  oriLen /= 3;
  pos = oriLen % fzKeyLen;
  for (; i < oriLen; ++i) {
    targetStr[i] = ((str[i * 3] - '0') * 100 + (str[(i * 3) + 1] - '0') * 10 +
                  (str[(i * 3) + 2] - '0')) ^
                 fzKey[(i + pos) % fzKeyLen];
  }
  targetStr[i] = 0;
  return targetStr;
}

int main(int argc, char *argv[]) {
  int i = 1;
  if (argc <= 1) {
    printf("Format is: fzDecrypt password1 password2 ...\n");
    return -1;
  }
  for (; i < argc; ++i) {
    char dbuff[256];
    printf("%s -> %s\n", argv[i], decrypt(argv[i], dbuff));
  }
  return 0;
}