MD5算法在JS中的实现

<script language="javascript"><!--/*********************************************************** md5.js** a javascript implementation of the rsa data security, inc. md5* message-digest algorithm.** copyright (c) paul johnston 1999. distributed under the lgpl.***********************************************************/

/* to convert strings to a list of ascii values */var sascii = " !\"#$%&'()*+,-./0123456789:;<=>?@abcdefghijklmnopqrstuvwxyz"var sascii = sascii + "[\\]^_`abcdefghijklmnopqrstuvwxyz{|}~";

/* convert integer to hex string */var shex = "0123456789abcdef";function hex(i){h = "";for(j = 0; j <= 3; j++){h += shex.charat((i >> (j * 8 + 4)) & 0x0f) +shex.charat((i >> (j * 8)) & 0x0f);}return h;}

/* add, handling overflows correctly */function add(x, y){return ((x&0x7fffffff) + (y&0x7fffffff)) ^ (x&0x80000000) ^ (y&0x80000000);}

/* md5 rounds functions */function r1(a, b, c, d, x, s, t){q = add(add(a, (b & c) | (~b & d)), add(x, t));return add((q << s) | ((q >> (32 - s)) & (math.pow(2, s) - 1)), b);}

function r2(a, b, c, d, x, s, t){q = add(add(a, (b & d) | (c & ~d)), add(x, t));return add((q << s) | ((q >> (32 - s)) & (math.pow(2, s) - 1)), b);}

function r3(a, b, c, d, x, s, t){q = add(add(a, b ^ c ^ d), add(x, t));return add((q << s) | ((q >> (32 - s)) & (math.pow(2, s) - 1)), b);}

function r4(a, b, c, d, x, s, t){q = add(add(a, c ^ (b | ~d)), add(x, t));return add((q << s) | ((q >> (32 - s)) & (math.pow(2, s) - 1)), b);}

/* main entry point */function calcmd5(sinp) {

/* calculate length in machine words, including padding */wlen = (((sinp.length + 8) >> 6) + 1) << 4;var x = new array(wlen);

/* convert string to array of words */j = 4;for (i = 0; (i * 4) < sinp.length; i++){x[i] = 0;for (j = 0; (j < 4) && ((j + i * 4) < sinp.length); j++){x[i] += (sascii.indexof(sinp.charat((i * 4) + j)) + 32) << (j * 8);}}

/* append padding bits and length */if (j == 4){x[i++] = 0x80;}else{x[i - 1] += 0x80 << (j * 8);}for(; i < wlen; i++) { x[i] = 0; }x[wlen - 2] = sinp.length * 8;

/* hard-coded initial values */a = 0x67452301;b = 0xefcdab89;c = 0x98badcfe;d = 0x10325476;

/* process each 16-word block in turn */for (i = 0; i < wlen; i += 16) {ao = a;bo = b;co = c;do = d;

a = r1(a, b, c, d, x[i+ 0], 7 , 0xd76aa478);d = r1(d, a, b, c, x[i+ 1], 12, 0xe8c7b756);c = r1(c, d, a, b, x[i+ 2], 17, 0x242070db);b = r1(b, c, d, a, x[i+ 3], 22, 0xc1bdceee);a = r1(a, b, c, d, x[i+ 4], 7 , 0xf57c0faf);d = r1(d, a, b, c, x[i+ 5], 12, 0x4787c62a);c = r1(c, d, a, b, x[i+ 6], 17, 0xa8304613);b = r1(b, c, d, a, x[i+ 7], 22, 0xfd469501);a = r1(a, b, c, d, x[i+ 8], 7 , 0x698098d8);d = r1(d, a, b, c, x[i+ 9], 12, 0x8b44f7af);c = r1(c, d, a, b, x[i+10], 17, 0xffff5bb1);b = r1(b, c, d, a, x[i+11], 22, 0x895cd7be);a = r1(a, b, c, d, x[i+12], 7 , 0x6b901122);d = r1(d, a, b, c, x[i+13], 12, 0xfd987193);c = r1(c, d, a, b, x[i+14], 17, 0xa679438e);b = r1(b, c, d, a, x[i+15], 22, 0x49b40821);

a = r2(a, b, c, d, x[i+ 1], 5 , 0xf61e2562);d = r2(d, a, b, c, x[i+ 6], 9 , 0xc040b340);c = r2(c, d, a, b, x[i+11], 14, 0x265e5a51);b = r2(b, c, d, a, x[i+ 0], 20, 0xe9b6c7aa);a = r2(a, b, c, d, x[i+ 5], 5 , 0xd62f105d);d = r2(d, a, b, c, x[i+10], 9 , 0x2441453);c = r2(c, d, a, b, x[i+15], 14, 0xd8a1e681);b = r2(b, c, d, a, x[i+ 4], 20, 0xe7d3fbc8);a = r2(a, b, c, d, x[i+ 9], 5 , 0x21e1cde6);d = r2(d, a, b, c, x[i+14], 9 , 0xc33707d6);c = r2(c, d, a, b, x[i+ 3], 14, 0xf4d50d87);b = r2(b, c, d, a, x[i+ 8], 20, 0x455a14ed);a = r2(a, b, c, d, x[i+13], 5 , 0xa9e3e905);d = r2(d, a, b, c, x[i+ 2], 9 , 0xfcefa3f8);c = r2(c, d, a, b, x[i+ 7], 14, 0x676f02d9);b = r2(b, c, d, a, x[i+12], 20, 0x8d2a4c8a);

a = r3(a, b, c, d, x[i+ 5], 4 , 0xfffa3942);d = r3(d, a, b, c, x[i+ 8], 11, 0x8771f681);c = r3(c, d, a, b, x[i+11], 16, 0x6d9d6122);b = r3(b, c, d, a, x[i+14], 23, 0xfde5380c);a = r3(a, b, c, d, x[i+ 1], 4 , 0xa4beea44);d = r3(d, a, b, c, x[i+ 4], 11, 0x4bdecfa9);c = r3(c, d, a, b, x[i+ 7], 16, 0xf6bb4b60);b = r3(b, c, d, a, x[i+10], 23, 0xbebfbc70);a = r3(a, b, c, d, x[i+13], 4 , 0x289b7ec6);d = r3(d, a, b, c, x[i+ 0], 11, 0xeaa127fa);c = r3(c, d, a, b, x[i+ 3], 16, 0xd4ef3085);b = r3(b, c, d, a, x[i+ 6], 23, 0x4881d05);a = r3(a, b, c, d, x[i+ 9], 4 , 0xd9d4d039);d = r3(d, a, b, c, x[i+12], 11, 0xe6db99e5);c = r3(c, d, a, b, x[i+15], 16, 0x1fa27cf8);b = r3(b, c, d, a, x[i+ 2], 23, 0xc4ac5665);

a = r4(a, b, c, d, x[i+ 0], 6 , 0xf4292244);d = r4(d, a, b, c, x[i+ 7], 10, 0x432aff97);c = r4(c, d, a, b, x[i+14], 15, 0xab9423a7);b = r4(b, c, d, a, x[i+ 5], 21, 0xfc93a039);a = r4(a, b, c, d, x[i+12], 6 , 0x655b59c3);d = r4(d, a, b, c, x[i+ 3], 10, 0x8f0ccc92);c = r4(c, d, a, b, x[i+10], 15, 0xffeff47d);b = r4(b, c, d, a, x[i+ 1], 21, 0x85845dd1);a = r4(a, b, c, d, x[i+ 8], 6 , 0x6fa87e4f);d = r4(d, a, b, c, x[i+15], 10, 0xfe2ce6e0);c = r4(c, d, a, b, x[i+ 6], 15, 0xa3014314);b = r4(b, c, d, a, x[i+13], 21, 0x4e0811a1);a = r4(a, b, c, d, x[i+ 4], 6 , 0xf7537e82);d = r4(d, a, b, c, x[i+11], 10, 0xbd3af235);c = r4(c, d, a, b, x[i+ 2], 15, 0x2ad7d2bb);b = r4(b, c, d, a, x[i+ 9], 21, 0xeb86d391);

a = add(a, ao);b = add(b, bo);c = add(c, co);d = add(d, do);}return hex(a) + hex(b) + hex(c) + hex(d);}

alert(hex("123456"))//--></script>