用法：

md5Value = hex_md5("asdfasdf")

<script>

/** A JavaScript implementation of the RSA Data Security, Inc. MD5 Message* Digest Algorithm, as defined in RFC 1321.* Version 2.1 Copyright (C) Paul Johnston 1999 - 2002.* Other contributors: Greg Holt, Andrew Kepert, Ydnar, Lostinet* Distributed under the BSD License* See http://pajhome.org.uk/crypt/md5 for more info.*/

/** Configurable variables. You may need to tweak these to be compatible with* the server-side, but the defaults work in most cases.*/var hexcase = 0; /* hex output format. 0 - lowercase; 1 - uppercase */var b64pad = ""; /* base-64 pad character. "=" for strict RFC compliance */var chrsz = 8; /* bits per input character. 8 - ASCII; 16 - Unicode */

/** These are the functions you'll usually want to call* They take string arguments and return either hex or base-64 encoded strings*/function hex_md5(s){ return binl2hex(core_md5(str2binl(s), s.length * chrsz));}function b64_md5(s){ return binl2b64(core_md5(str2binl(s), s.length * chrsz));}function str_md5(s){ return binl2str(core_md5(str2binl(s), s.length * chrsz));}function hex_hmac_md5(key, data) { return binl2hex(core_hmac_md5(key, data)); }function b64_hmac_md5(key, data) { return binl2b64(core_hmac_md5(key, data)); }function str_hmac_md5(key, data) { return binl2str(core_hmac_md5(key, data)); }

/** Perform a simple self-test to see if the VM is working*/function md5_vm_test(){return hex_md5("abc") == "900150983cd24fb0d6963f7d28e17f72";}

/** Calculate the MD5 of an array of little-endian words, and a bit length*/function core_md5(x, len){/* append padding */x[len >> 5] |= 0x80 << ((len) % 32);x[(((len + 64) >>> 9) << 4) + 14] = len;

var a = 1732584193;var b = -271733879;var c = -1732584194;var d = 271733878;

for(var i = 0; i < x.length; i += 16){var olda = a;var oldb = b;var oldc = c;var oldd = d;

a = md5_ff(a, b, c, d, x[i+ 0], 7 , -680876936);d = md5_ff(d, a, b, c, x[i+ 1], 12, -389564586);c = md5_ff(c, d, a, b, x[i+ 2], 17, 606105819);b = md5_ff(b, c, d, a, x[i+ 3], 22, -1044525330);a = md5_ff(a, b, c, d, x[i+ 4], 7 , -176418897);d = md5_ff(d, a, b, c, x[i+ 5], 12, 1200080426);c = md5_ff(c, d, a, b, x[i+ 6], 17, -1473231341);b = md5_ff(b, c, d, a, x[i+ 7], 22, -45705983);a = md5_ff(a, b, c, d, x[i+ 8], 7 , 1770035416);d = md5_ff(d, a, b, c, x[i+ 9], 12, -1958414417);c = md5_ff(c, d, a, b, x[i+10], 17, -42063);b = md5_ff(b, c, d, a, x[i+11], 22, -1990404162);a = md5_ff(a, b, c, d, x[i+12], 7 , 1804603682);d = md5_ff(d, a, b, c, x[i+13], 12, -40341101);c = md5_ff(c, d, a, b, x[i+14], 17, -1502002290);b = md5_ff(b, c, d, a, x[i+15], 22, 1236535329);

a = md5_gg(a, b, c, d, x[i+ 1], 5 , -165796510);d = md5_gg(d, a, b, c, x[i+ 6], 9 , -1069501632);c = md5_gg(c, d, a, b, x[i+11], 14, 643717713);b = md5_gg(b, c, d, a, x[i+ 0], 20, -373897302);a = md5_gg(a, b, c, d, x[i+ 5], 5 , -701558691);d = md5_gg(d, a, b, c, x[i+10], 9 , 38016083);c = md5_gg(c, d, a, b, x[i+15], 14, -660478335);b = md5_gg(b, c, d, a, x[i+ 4], 20, -405537848);a = md5_gg(a, b, c, d, x[i+ 9], 5 , 568446438);d = md5_gg(d, a, b, c, x[i+14], 9 , -1019803690);c = md5_gg(c, d, a, b, x[i+ 3], 14, -187363961);b = md5_gg(b, c, d, a, x[i+ 8], 20, 1163531501);a = md5_gg(a, b, c, d, x[i+13], 5 , -1444681467);d = md5_gg(d, a, b, c, x[i+ 2], 9 , -51403784);c = md5_gg(c, d, a, b, x[i+ 7], 14, 1735328473);b = md5_gg(b, c, d, a, x[i+12], 20, -1926607734);

a = md5_hh(a, b, c, d, x[i+ 5], 4 , -378558);d = md5_hh(d, a, b, c, x[i+ 8], 11, -2022574463);c = md5_hh(c, d, a, b, x[i+11], 16, 1839030562);b = md5_hh(b, c, d, a, x[i+14], 23, -35309556);a = md5_hh(a, b, c, d, x[i+ 1], 4 , -1530992060);d = md5_hh(d, a, b, c, x[i+ 4], 11, 1272893353);c = md5_hh(c, d, a, b, x[i+ 7], 16, -155497632);b = md5_hh(b, c, d, a, x[i+10], 23, -1094730640);a = md5_hh(a, b, c, d, x[i+13], 4 , 681279174);d = md5_hh(d, a, b, c, x[i+ 0], 11, -358537222);c = md5_hh(c, d, a, b, x[i+ 3], 16, -722521979);b = md5_hh(b, c, d, a, x[i+ 6], 23, 76029189);a = md5_hh(a, b, c, d, x[i+ 9], 4 , -640364487);d = md5_hh(d, a, b, c, x[i+12], 11, -421815835);c = md5_hh(c, d, a, b, x[i+15], 16, 530742520);b = md5_hh(b, c, d, a, x[i+ 2], 23, -995338651);

a = md5_ii(a, b, c, d, x[i+ 0], 6 , -198630844);d = md5_ii(d, a, b, c, x[i+ 7], 10, 1126891415);c = md5_ii(c, d, a, b, x[i+14], 15, -1416354905);b = md5_ii(b, c, d, a, x[i+ 5], 21, -57434055);a = md5_ii(a, b, c, d, x[i+12], 6 , 1700485571);d = md5_ii(d, a, b, c, x[i+ 3], 10, -1894986606);c = md5_ii(c, d, a, b, x[i+10], 15, -1051523);b = md5_ii(b, c, d, a, x[i+ 1], 21, -2054922799);a = md5_ii(a, b, c, d, x[i+ 8], 6 , 1873313359);d = md5_ii(d, a, b, c, x[i+15], 10, -30611744);c = md5_ii(c, d, a, b, x[i+ 6], 15, -1560198380);b = md5_ii(b, c, d, a, x[i+13], 21, 1309151649);a = md5_ii(a, b, c, d, x[i+ 4], 6 , -145523070);d = md5_ii(d, a, b, c, x[i+11], 10, -1120210379);c = md5_ii(c, d, a, b, x[i+ 2], 15, 718787259);b = md5_ii(b, c, d, a, x[i+ 9], 21, -343485551);

a = safe_add(a, olda);b = safe_add(b, oldb);c = safe_add(c, oldc);d = safe_add(d, oldd);}return Array(a, b, c, d);

}

/** These functions implement the four basic operations the algorithm uses.*/function md5_cmn(q, a, b, x, s, t){return safe_add(bit_rol(safe_add(safe_add(a, q), safe_add(x, t)), s),b);}function md5_ff(a, b, c, d, x, s, t){return md5_cmn((b & c) | ((~b) & d), a, b, x, s, t);}function md5_gg(a, b, c, d, x, s, t){return md5_cmn((b & d) | (c & (~d)), a, b, x, s, t);}function md5_hh(a, b, c, d, x, s, t){return md5_cmn(b ^ c ^ d, a, b, x, s, t);}function md5_ii(a, b, c, d, x, s, t){return md5_cmn(c ^ (b | (~d)), a, b, x, s, t);}

/** Calculate the HMAC-MD5, of a key and some data*/function core_hmac_md5(key, data){var bkey = str2binl(key);if(bkey.length > 16) bkey = core_md5(bkey, key.length * chrsz);

var ipad = Array(16), opad = Array(16);for(var i = 0; i < 16; i++){ipad[i] = bkey[i] ^ 0x36363636;opad[i] = bkey[i] ^ 0x5C5C5C5C;}

var hash = core_md5(ipad.concat(str2binl(data)), 512 + data.length * chrsz);return core_md5(opad.concat(hash), 512 + 128);}

/** Add integers, wrapping at 2^32. This uses 16-bit operations internally* to work around bugs in some JS interpreters.*/function safe_add(x, y){var lsw = (x & 0xFFFF) + (y & 0xFFFF);var msw = (x >> 16) + (y >> 16) + (lsw >> 16);return (msw << 16) | (lsw & 0xFFFF);}

/** Bitwise rotate a 32-bit number to the left.*/function bit_rol(num, cnt){return (num << cnt) | (num >>> (32 - cnt));}

/** Convert a string to an array of little-endian words* If chrsz is ASCII, characters >255 have their hi-byte silently ignored.*/function str2binl(str){var bin = Array();var mask = (1 << chrsz) - 1;for(var i = 0; i < str.length * chrsz; i += chrsz)bin[i>>5] |= (str.charCodeAt(i / chrsz) & mask) << (i%32);return bin;}

/** Convert an array of little-endian words to a string*/function binl2str(bin){var str = "";var mask = (1 << chrsz) - 1;for(var i = 0; i < bin.length * 32; i += chrsz)str += String.fromCharCode((bin[i>>5] >>> (i % 32)) & mask);return str;}

/** Convert an array of little-endian words to a hex string.*/function binl2hex(binarray){var hex_tab = hexcase ? "0123456789ABCDEF" : "0123456789abcdef";var str = "";for(var i = 0; i < binarray.length * 4; i++){str += hex_tab.charAt((binarray[i>>2] >> ((i%4)*8+4)) & 0xF) +hex_tab.charAt((binarray[i>>2] >> ((i%4)*8 )) & 0xF);}return str;}

/** Convert an array of little-endian words to a base-64 string*/function binl2b64(binarray){var tab = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";var str = "";for(var i = 0; i < binarray.length * 4; i += 3){var triplet = (((binarray[i >> 2] >> 8 * ( i %4)) & 0xFF) << 16)| (((binarray[i+1 >> 2] >> 8 * ((i+1)%4)) & 0xFF) << 8 )| ((binarray[i+2 >> 2] >> 8 * ((i+2)%4)) & 0xFF);for(var j = 0; j < 4; j++){if(i * 8 + j * 6 > binarray.length * 32) str += b64pad;else str += tab.charAt((triplet >> 6*(3-j)) & 0x3F);}}return str;}</script>