java版的 MD5

public class MD5 { /* * A Java implementation of the RSA Data Security, Inc. MD5 Message * Digest Algorithm, as defined in RFC 1321. * Based on the JavaScript implementation of Paul Johnston * Copyright (C) Paul Johnston 1999 - 2000. * See http://pajhome.org.uk/site/legal.html for details. * Java Version by Thomas Weber (Orange Interactive GmbH) */ /* * Convert a 32-bit number to a hex string with ls-byte first */ String hex_chr = "0123456789abcdef"; private String rhex(int num) { String str = ""; for(int j = 0; j <= 3; j++) str = str + hex_chr.charAt((num >> (j * 8 + 4)) & 0x0F) + hex_chr.charAt((num >> (j * 8)) & 0x0F); return str; } /* * Convert a string to a sequence of 16-word blocks, stored as an array. * Append padding bits and the length, as described in the MD5 standard. */ private int[] str2blks_MD5(String str) { int nblk = ((str.length() + 8) >> 6) + 1; int[] blks = new int[nblk * 16]; int i = 0; for(i = 0; i < nblk * 16; i++) { blks[i] = 0; } for(i = 0; i < str.length(); i++) { blks[i >> 2] |= str.charAt(i) << ((i % 4) * 8); } blks[i >> 2] |= 0x80 << ((i % 4) * 8); blks[nblk * 16 - 2] = str.length()*8; return blks; } /* * Add integers, wrapping at 2^32 */ private int add(int x, int y) { return ((x&0x7FFFFFFF) + (y&0x7FFFFFFF)) ^ (x&0x80000000) ^ (y&0x80000000); } /* * Bitwise rotate a 32-bit number to the left */ private int rol(int num, int cnt) { return (num << cnt) | (num >>> (32 - cnt)); } /* * These functions implement the basic operation for each round of the * algorithm. */ private int cmn(int q, int a, int b, int x, int s, int t) { return add(rol(add(add(a, q), add(x, t)), s), b); } private int ff(int a, int b, int c, int d, int x, int s, int t) { return cmn((b & c) | ((~b) & d), a, b, x, s, t); } private int gg(int a, int b, int c, int d, int x, int s, int t) { return cmn((b & d) | (c & (~d)), a, b, x, s, t); } private int hh(int a, int b, int c, int d, int x, int s, int t) { return cmn(b ^ c ^ d, a, b, x, s, t); } private int ii(int a, int b, int c, int d, int x, int s, int t) { return cmn(c ^ (b | (~d)), a, b, x, s, t); } /* * Take a string and return the hex representation of its MD5. */ public String calcMD5(String str) { int[] x = str2blks_MD5(str); int a = 0x67452301; int b = 0xEFCDAB89; int c = 0x98BADCFE; int d = 0x10325476; for(int i = 0; i < x.length; i += 16) { int olda = a; int oldb = b; int oldc = c; int oldd = d; a = ff(a, b, c, d, x[i+ 0], 7 , 0xD76AA478); d = ff(d, a, b, c, x[i+ 1], 12, 0xE8C7B756); c = ff(c, d, a, b, x[i+ 2], 17, 0x242070DB); b = ff(b, c, d, a, x[i+ 3], 22, 0xC1BDCEEE); a = ff(a, b, c, d, x[i+ 4], 7 , 0xF57C0FAF); d = ff(d, a, b, c, x[i+ 5], 12, 0x4787C62A); c = ff(c, d, a, b, x[i+ 6], 17, 0xA8304613); b = ff(b, c, d, a, x[i+ 7], 22, 0xFD469501); a = ff(a, b, c, d, x[i+ 8], 7 , 0x698098D8); d = ff(d, a, b, c, x[i+ 9], 12, 0x8B44F7AF); c = ff(c, d, a, b, x[i+10], 17, 0xFFFF5BB1); b = ff(b, c, d, a, x[i+11], 22, 0x895CD7BE); a = ff(a, b, c, d, x[i+12], 7 , 0x6B901122); d = ff(d, a, b, c, x[i+13], 12, 0xFD987193); c = ff(c, d, a, b, x[i+14], 17, 0xA679438E); b = ff(b, c, d, a, x[i+15], 22, 0x49B40821); a = gg(a, b, c, d, x[i+ 1], 5 , 0xF61E2562); d = gg(d, a, b, c, x[i+ 6], 9 , 0xC040B340); c = gg(c, d, a, b, x[i+11], 14, 0x265E5A51); b = gg(b, c, d, a, x[i+ 0], 20, 0xE9B6C7AA); a = gg(a, b, c, d, x[i+ 5], 5 , 0xD62F105D); d = gg(d, a, b, c, x[i+10], 9 , 0x02441453); c = gg(c, d, a, b, x[i+15], 14, 0xD8A1E681); b = gg(b, c, d, a, x[i+ 4], 20, 0xE7D3FBC8); a = gg(a, b, c, d, x[i+ 9], 5 , 0x21E1CDE6); d = gg(d, a, b, c, x[i+14], 9 , 0xC33707D6); c = gg(c, d, a, b, x[i+ 3], 14, 0xF4D50D87); b = gg(b, c, d, a, x[i+ 8], 20, 0x455A14ED); a = gg(a, b, c, d, x[i+13], 5 , 0xA9E3E905); d = gg(d, a, b, c, x[i+ 2], 9 , 0xFCEFA3F8); c = gg(c, d, a, b, x[i+ 7], 14, 0x676F02D9); b = gg(b, c, d, a, x[i+12], 20, 0x8D2A4C8A); a = hh(a, b, c, d, x[i+ 5], 4 , 0xFFFA3942); d = hh(d, a, b, c, x[i+ 8], 11, 0x8771F681); c = hh(c, d, a, b, x[i+11], 16, 0x6D9D6122); b = hh(b, c, d, a, x[i+14], 23, 0xFDE5380C); a = hh(a, b, c, d, x[i+ 1], 4 , 0xA4BEEA44); d = hh(d, a, b, c, x[i+ 4], 11, 0x4BDECFA9); c = hh(c, d, a, b, x[i+ 7], 16, 0xF6BB4B60); b = hh(b, c, d, a, x[i+10], 23, 0xBEBFBC70); a = hh(a, b, c, d, x[i+13], 4 , 0x289B7EC6); d = hh(d, a, b, c, x[i+ 0], 11, 0xEAA127FA); c = hh(c, d, a, b, x[i+ 3], 16, 0xD4EF3085); b = hh(b, c, d, a, x[i+ 6], 23, 0x04881D05); a = hh(a, b, c, d, x[i+ 9], 4 , 0xD9D4D039); d = hh(d, a, b, c, x[i+12], 11, 0xE6DB99E5); c = hh(c, d, a, b, x[i+15], 16, 0x1FA27CF8); b = hh(b, c, d, a, x[i+ 2], 23, 0xC4AC5665); a = ii(a, b, c, d, x[i+ 0], 6 , 0xF4292244); d = ii(d, a, b, c, x[i+ 7], 10, 0x432AFF97); c = ii(c, d, a, b, x[i+14], 15, 0xAB9423A7); b = ii(b, c, d, a, x[i+ 5], 21, 0xFC93A039); a = ii(a, b, c, d, x[i+12], 6 , 0x655B59C3); d = ii(d, a, b, c, x[i+ 3], 10, 0x8F0CCC92); c = ii(c, d, a, b, x[i+10], 15, 0xFFEFF47D); b = ii(b, c, d, a, x[i+ 1], 21, 0x85845DD1); a = ii(a, b, c, d, x[i+ 8], 6 , 0x6FA87E4F); d = ii(d, a, b, c, x[i+15], 10, 0xFE2CE6E0); c = ii(c, d, a, b, x[i+ 6], 15, 0xA3014314); b = ii(b, c, d, a, x[i+13], 21, 0x4E0811A1); a = ii(a, b, c, d, x[i+ 4], 6 , 0xF7537E82); d = ii(d, a, b, c, x[i+11], 10, 0xBD3AF235); c = ii(c, d, a, b, x[i+ 2], 15, 0x2AD7D2BB); b = ii(b, c, d, a, x[i+ 9], 21, 0xEB86D391); a = add(a, olda); b = add(b, oldb); c = add(c, oldc); d = add(d, oldd); } return rhex(a) + rhex(b) + rhex(c) + rhex(d); } }