/***
* jwma Java WebMail
* Copyright (c) 2000-2003 jwma team
*
* jwma is free software; you can distribute and use this source
* under the terms of the BSD-style license received along with
* the distribution.
 ***/package com.struts2.framework.util;/**
 * This class implements the MD5 algorithm.
 * <p>
 * The specification is available from RFC 1321,
 * and there are numerous implementations out there,
 * this one was tuned specifically for hashing short
 * strings (i.e. passwords).
 * <p>
 * I do not recommend to use this implementation for
 * anything else but that, and if anybody feels that
 * this code is to "close" to something available on
 * the net, please contact me, and I will certainly take
 * steps to clear up the situation.
 */public final class MD5 {  /**
   * Returns the MD5 hash digest transformed into a hex
   * representation as <tt>String</tt>.
   *
   * @return the MD5 hash of the input as <tt>String</tt>.
   */  public static final String hash(String str) {    return MD5.asHex(MD5.digest(str.getBytes()));  }//hash  /**
   * Returns the MD5 hash of the input data.
   * <p>
   * Following the the MD5 standard specification, the result
   * is returned least significant byte first, however,
   * many applications use the most significant byte first (more conventional).
   *
   * @param msg the <tt>byte[]</tt> to be digested.
   *
   * @return the MD5 hash of the data as <tt>String</tt>.
   */  public static final byte[] digest(byte[] msg) {    int padsize = (120 - (msg.length % 64)) % 64;    int i;    long l = msg.length * 8;

    //MD5 registers
    int a = 0x67452301, aa,
        b = 0xefcdab89, bb,
        c = 0x98badcfe, cc,
        d = 0x10325476, dd;    byte[] src = new byte[msg.length + padsize + 8];

    //padding
    try {      System.arraycopy(msg, 0, src, 0, msg.length);    } catch (Exception ex) {      //should not happen, but calm's the compiler    }    src[msg.length] = (byte) 0x80;    for (i = msg.length + 1; i < msg.length + padsize; i++) src[i] = 0;

    //append length
    for (i = src.length - 8; i < src.length; i++) {      src[i] = (byte) l;      l >>>= 8;    }    int[] x = new int[16];

    //prcess the data 16-word blocks
    for (i = 0; i < src.length; i += 64) {      //construct block
      for (int j = 0; j < 16; j++) {        x[j] = 0;        for (int k = 3; k >= 0; k--) {          x[j] <<= 8;          x[j] += src[i + j * 4 + k] & 0xff;        }      }      aa = a;      bb = b;      cc = c;      dd = d;      a = round1(a, b, c, d, 0, 7, 1, x);      d = round1(d, a, b, c, 1, 12, 2, x);      c = round1(c, d, a, b, 2, 17, 3, x);      b = round1(b, c, d, a, 3, 22, 4, x);      a = round1(a, b, c, d, 4, 7, 5, x);      d = round1(d, a, b, c, 5, 12, 6, x);      c = round1(c, d, a, b, 6, 17, 7, x);      b = round1(b, c, d, a, 7, 22, 8, x);      a = round1(a, b, c, d, 8, 7, 9, x);      d = round1(d, a, b, c, 9, 12, 10, x);      c = round1(c, d, a, b, 10, 17, 11, x);      b = round1(b, c, d, a, 11, 22, 12, x);      a = round1(a, b, c, d, 12, 7, 13, x);      d = round1(d, a, b, c, 13, 12, 14, x);      c = round1(c, d, a, b, 14, 17, 15, x);      b = round1(b, c, d, a, 15, 22, 16, x);      a = round2(a, b, c, d, 1, 5, 17, x);      d = round2(d, a, b, c, 6, 9, 18, x);      c = round2(c, d, a, b, 11, 14, 19, x);      b = round2(b, c, d, a, 0, 20, 20, x);      a = round2(a, b, c, d, 5, 5, 21, x);      d = round2(d, a, b, c, 10, 9, 22, x);      c = round2(c, d, a, b, 15, 14, 23, x);      b = round2(b, c, d, a, 4, 20, 24, x);      a = round2(a, b, c, d, 9, 5, 25, x);      d = round2(d, a, b, c, 14, 9, 26, x);      c = round2(c, d, a, b, 3, 14, 27, x);      b = round2(b, c, d, a, 8, 20, 28, x);      a = round2(a, b, c, d, 13, 5, 29, x);      d = round2(d, a, b, c, 2, 9, 30, x);      c = round2(c, d, a, b, 7, 14, 31, x);      b = round2(b, c, d, a, 12, 20, 32, x);      a = round3(a, b, c, d, 5, 4, 33, x);      d = round3(d, a, b, c, 8, 11, 34, x);      c = round3(c, d, a, b, 11, 16, 35, x);      b = round3(b, c, d, a, 14, 23, 36, x);      a = round3(a, b, c, d, 1, 4, 37, x);      d = round3(d, a, b, c, 4, 11, 38, x);      c = round3(c, d, a, b, 7, 16, 39, x);      b = round3(b, c, d, a, 10, 23, 40, x);      a = round3(a, b, c, d, 13, 4, 41, x);      d = round3(d, a, b, c, 0, 11, 42, x);      c = round3(c, d, a, b, 3, 16, 43, x);      b = round3(b, c, d, a, 6, 23, 44, x);      a = round3(a, b, c, d, 9, 4, 45, x);      d = round3(d, a, b, c, 12, 11, 46, x);      c = round3(c, d, a, b, 15, 16, 47, x);      b = round3(b, c, d, a, 2, 23, 48, x);      a = round4(a, b, c, d, 0, 6, 49, x);      d = round4(d, a, b, c, 7, 10, 50, x);      c = round4(c, d, a, b, 14, 15, 51, x);      b = round4(b, c, d, a, 5, 21, 52, x);      a = round4(a, b, c, d, 12, 6, 53, x);      d = round4(d, a, b, c, 3, 10, 54, x);      c = round4(c, d, a, b, 10, 15, 55, x);      b = round4(b, c, d, a, 1, 21, 56, x);      a = round4(a, b, c, d, 8, 6, 57, x);      d = round4(d, a, b, c, 15, 10, 58, x);      c = round4(c, d, a, b, 6, 15, 59, x);      b = round4(b, c, d, a, 13, 21, 60, x);      a = round4(a, b, c, d, 4, 6, 61, x);      d = round4(d, a, b, c, 11, 10, 62, x);      c = round4(c, d, a, b, 2, 15, 63, x);      b = round4(b, c, d, a, 9, 21, 64, x);      a += aa;      b += bb;      c += cc;      d += dd;    }    byte[] ret = new byte[16];    for (i = 0; i < 4; i++) {      ret[i] = (byte) a;      a >>>= 8;    }    for (; i < 8; i++) {      ret[i] = (byte) b;      b >>>= 8;    }    for (; i < 12; i++) {      ret[i] = (byte) c;      c >>>= 8;    }    for (; i < 16; i++) {      ret[i] = (byte) d;      d >>>= 8;    }    return ret;  }//digest  /** MD5 Transformation routines *********************************************/  private static final int rot(int x, int s) {    return x << s | x >>> (32 - s);  }//rot  private static final int F(int x, int y, int z) {    return (x & y) | (~x & z);  }//F  private static final int G(int x, int y, int z) {    return (x & z) | (y & ~z);  }//G  private static final int H(int x, int y, int z) {    return x ^ y ^ z;  }//H  private static final int I(int x, int y, int z) {    return y ^ (x | ~z);  }//I  private static final int round1(int a, int b, int c,                                  int d, int k, int s,                                  int i, int[] x) {    return b + rot((a + F(b, c, d) + x[k] + T[i - 1]), s);  }//round1  private static final int round2(int a, int b, int c,                                  int d, int k, int s,                                  int i, int[] x) {    return b + rot((a + G(b, c, d) + x[k] + T[i - 1]), s);  }//round2  private static final int round3(int a, int b, int c,                                  int d, int k, int s,                                  int i, int[] x) {    return b + rot((a + H(b, c, d) + x[k] + T[i - 1]), s);  }//round3  private static final int round4(int a, int b, int c,                                  int d, int k, int s,                                  int i, int[] x) {    return b + rot((a + I(b, c, d) + x[k] + T[i - 1]), s);  }//round4  private static final int T[] = {    0xd76aa478, 0xe8c7b756, 0x242070db, 0xc1bdceee, 0xf57c0faf,    0x4787c62a, 0xa8304613, 0xfd469501, 0x698098d8, 0x8b44f7af,    0xffff5bb1, 0x895cd7be, 0x6b901122, 0xfd987193, 0xa679438e,    0x49b40821, 0xf61e2562, 0xc040b340, 0x265e5a51, 0xe9b6c7aa,    0xd62f105d, 0x02441453, 0xd8a1e681, 0xe7d3fbc8, 0x21e1cde6,    0xc33707d6, 0xf4d50d87, 0x455a14ed, 0xa9e3e905, 0xfcefa3f8,    0x676f02d9, 0x8d2a4c8a, 0xfffa3942, 0x8771f681, 0x6d9d6122,    0xfde5380c, 0xa4beea44, 0x4bdecfa9, 0xf6bb4b60, 0xbebfbc70,    0x289b7ec6, 0xeaa127fa, 0xd4ef3085, 0x04881d05, 0xd9d4d039,    0xe6db99e5, 0x1fa27cf8, 0xc4ac5665, 0xf4292244, 0x432aff97,    0xab9423a7, 0xfc93a039, 0x655b59c3, 0x8f0ccc92, 0xffeff47d,    0x85845dd1, 0x6fa87e4f, 0xfe2ce6e0, 0xa3014314, 0x4e0811a1,    0xf7537e82, 0xbd3af235, 0x2ad7d2bb, 0xeb86d391  };

  /** END MD5 Transformation routines *****************************************/

  /**
   * Returns a <tt>String</tt> containing unsigned hexadecimal
   * numbers as digits.
   * <p>
   * Contains two hex digit characters for each byte from the passed in
   * <tt>byte[]</tt>.
   *
   * @param data the array of bytes to be converted into a hex-string.
   * @return	the generated hexadecimal representation as
   *          <tt>String</tt>.
   */  public static final String asHex(byte[] data) {    //double size, two bytes (hex range) for one byte
    StringBuffer buf = new StringBuffer(data.length * 2);    for (int i = 0; i < data.length; i++) {      //don't forget the second hex digit
      if (((int) data[i] & 0xff) < 0x10) {        buf.append("0");      }      buf.append(Long.toString((int) data[i] & 0xff, 16));    }    return buf.toString();  }//asHex  /**
   * A main, to allow using this class from the command line.
   */  public static void main(String[] args) {    try {      if (args == null || args.length == 0) {        System.out.println("Usage: java com.imb.util.MD5 <password>");      }      System.out.println("Hash=" + hash(args[0]));    } catch (Exception ex) {      ex.printStackTrace();    }  }//main}//class MD5