/*
 * 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.
 */

var MD5 = (function () {
    /*
     * 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 */

    /*
     * Add integers, wrapping at 2^32. This uses 16-bit operations internally
     * to work around bugs in some JS interpreters.
     */
    var safe_add = function (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.
     */
    var bit_rol = function (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.
     */
    var str2binl = function (str) {
        var bin = [];
        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
     */
    var binl2str = function (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.
     */
    var binl2hex = function (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
     */
    var binl2b64 = function (binarray) {
        var tab = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
        var str = "";
        var triplet, j;
        for(var i = 0; i < binarray.length * 4; i += 3)
        {
            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(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;
    };

    /*
     * These functions implement the four basic operations the algorithm uses.
     */
    var md5_cmn = function (q, a, b, x, s, t) {
        return safe_add(bit_rol(safe_add(safe_add(a, q),safe_add(x, t)), s),b);
    };

    var md5_ff = function (a, b, c, d, x, s, t) {
        return md5_cmn((b & c) | ((~b) & d), a, b, x, s, t);
    };

    var md5_gg = function (a, b, c, d, x, s, t) {
        return md5_cmn((b & d) | (c & (~d)), a, b, x, s, t);
    };

    var md5_hh = function (a, b, c, d, x, s, t) {
        return md5_cmn(b ^ c ^ d, a, b, x, s, t);
    };

    var md5_ii = function (a, b, c, d, x, s, t) {
        return md5_cmn(c ^ (b | (~d)), a, b, x, s, t);
    };

    /*
     * Calculate the MD5 of an array of little-endian words, and a bit length
     */
    var core_md5 = function (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;

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


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

        var ipad = new Array(16), opad = new 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);
    };

    var obj = {
        /*
         * These are the functions you'll usually want to call.
         * They take string arguments and return either hex or base-64 encoded
         * strings.
         */
        hexdigest: function (s) {
            return binl2hex(core_md5(str2binl(s), s.length * chrsz));
        },

        b64digest: function (s) {
            return binl2b64(core_md5(str2binl(s), s.length * chrsz));
        },

        hash: function (s) {
            return binl2str(core_md5(str2binl(s), s.length * chrsz));
        },

        hmac_hexdigest: function (key, data) {
            return binl2hex(core_hmac_md5(key, data));
        },

        hmac_b64digest: function (key, data) {
            return binl2b64(core_hmac_md5(key, data));
        },

        hmac_hash: function (key, data) {
            return binl2str(core_hmac_md5(key, data));
        },

        /*
         * Perform a simple self-test to see if the VM is working
         */
        test: function () {
            return MD5.hexdigest("abc") === "900150983cd24fb0d6963f7d28e17f72";
        }
    };

    return obj;
})();

// Nodify
exports.MD5 = MD5;
