* 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). *
* 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 String. * * @return the MD5 hash of the input as String. */ public static final String hash(String str) { return MD5.asHex(MD5.digest(str.getBytes())); }//hash /** * Returns the MD5 hash of the input data. *
* 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 byte[] to be digested. * * @return the MD5 hash of the data as String. */ 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 String containing unsigned hexadecimal * numbers as digits. *
* Contains two hex digit characters for each byte from the passed in
* byte[].
*
* @param data the array of bytes to be converted into a hex-string.
* @return the generated hexadecimal representation as
* String.
*/
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 dtw.webmail.util.MD5