/*
 * OpenP2M Crypt Break
 *
 * Encrypt and decrypt password for program OpenP2M.
 *
 * 06/05/2006 - frighetti AT cascavel.pm.org
 */

import java.lang.String;
import java.math.BigInteger;

class RSA
{
  private BigInteger n, d, e;

  public RSA()
  {
    n = new BigInteger("849613389756793222155926708916406526722137707856633" + 
           "710486677120848018911369507691157686832490341300851" + 
           "2741498700587851315525414979963642608998181269527941");
    d = new BigInteger("169922677951358644431185341783281305344427541571326" +
           "742097335424169603782273897848542211926500549462803" +
           "9077923965408489035118957525416966246759228390003017");
    e = new BigInteger("5");
  }

  public final String encrypt(String s) {
    return "_" + encrypt(new BigInteger(s.getBytes())).toString(36);
  }

  private BigInteger encrypt(BigInteger message)
  {
    return message.modPow(e, n);
  }

  public final String decrypt(String s) throws NumberFormatException
  {
    return s.startsWith("_") ?
      new String(decrypt(new BigInteger(s.substring(1), 36)).toByteArray()) :
      new String(decrypt(new BigInteger(s)).toByteArray());
  }

  private BigInteger decrypt(BigInteger message)
  {
    return message.modPow(d, n);
  }
}

public class openp2m_crypt
{
  private String enc = null, dec = null;
  
  public static void main(String[] args)
  {
    if (args.length <= 1)
      usage();

    System.out.println(" " + parseargs(args) + "\n");
  }

  public static void usage()
  {
    System.out.println("Usage: \n" +
           "      java openp2m_crypt [-c <string for crypt> | -d <password crypted>]\n" +
           "              -c : criptography password for openp2m\n" +
           "              -d : decriptography password for openp2m\n");
    System.exit(1);
    
  }

  public static String parseargs(String[] args)
  {
    RSA rsa = new RSA();
    
    for (int i = 0; i < args.length; i++)
    {
      if (args[i].equals("-c") && i+1<args.length)
      {
        return rsa.encrypt(args[++i]);
      }
      else if (args[i].equals("-d") && i+1<args.length)
      {
        return rsa.decrypt(args[++i]);
      }
    }

    return "";
  }
}