/*
    * A JavaScript implementation of the RSA Data Security, Inc. MD5 Message
    * Digest Algorithm, as defined in RFC 1321.
    * Version 1.1 Copyright (C) Paul Johnston 1999 - 2002.
    * Code also contributed by Greg Holt
    * See http://pajhome.org.uk/site/legal.html for details.
    */

    /*
    * 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 rol(num, cnt) {
        return (num << cnt) | (num >>> (32 - cnt))
    }

    /*
    * These functions implement the four basic operations the algorithm uses.
    */
    function cmn(q, a, b, x, s, t) {
        return safe_add(rol(safe_add(safe_add(a, q), safe_add(x, t)), s), b)
    }
    function ff(a, b, c, d, x, s, t) {
        return cmn((b & c) | ((~b) & d), a, b, x, s, t)
    }
    function gg(a, b, c, d, x, s, t) {
        return cmn((b & d) | (c & (~d)), a, b, x, s, t)
    }
    function hh(a, b, c, d, x, s, t) {
        return cmn(b ^ c ^ d, a, b, x, s, t)
    }
    function ii(a, b, c, d, x, s, t) {
        return cmn(c ^ (b | (~d)), a, b, x, s, t)
    }

    /*
    * Calculate the MD5 of an array of little-endian words, producing an array
    * of little-endian words.
    */
    function coreMD5(x) {
        var a = 1732584193
        var b = -271733879
        var c = -1732584194
        var d = 271733878

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

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

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

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

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

    /*
    * Convert an array of little-endian words to a hex string.
    */
    function binl2hex(binarray) {
        var hex_tab = "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 base64 encoded string.
    */
    function binl2b64(binarray) {
        var tab = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"
        var str = ""
        for (var i = 0; i < binarray.length * 32; i += 6) {
            str += tab.charAt(((binarray[i >> 5] << (i % 32)) & 0x3F) |
                      ((binarray[i >> 5 + 1] >> (32 - i % 32)) & 0x3F))
        }
        return str
    }

    /*
    * Convert an 8-bit character string to a sequence of 16-word blocks, stored
    * as an array, and append appropriate padding for MD4/5 calculation.
    * If any of the characters are >255, the high byte is silently ignored.
    */
    function str2binl(str) {
        var nblk = ((str.length + 8) >> 6) + 1 // number of 16-word blocks
        var blks = new Array(nblk * 16)
        for (var i = 0; i < nblk * 16; i++) blks[i] = 0
        for (var i = 0; i < str.length; i++)
            blks[i >> 2] |= (str.charCodeAt(i) & 0xFF) << ((i % 4) * 8)
        blks[i >> 2] |= 0x80 << ((i % 4) * 8)
        blks[nblk * 16 - 2] = str.length * 8
        return blks
    }

    /*
    * Convert a wide-character string to a sequence of 16-word blocks, stored as
    * an array, and append appropriate padding for MD4/5 calculation.
    */
    function strw2binl(str) {
        var nblk = ((str.length + 4) >> 5) + 1 // number of 16-word blocks
        var blks = new Array(nblk * 16)
        for (var i = 0; i < nblk * 16; i++) blks[i] = 0
        for (var i = 0; i < str.length; i++)
            blks[i >> 1] |= str.charCodeAt(i) << ((i % 2) * 16)
        blks[i >> 1] |= 0x80 << ((i % 2) * 16)
        blks[nblk * 16 - 2] = str.length * 16
        return blks
    }

    /*
    * External interface
    */
    function hexMD5(str) { return binl2hex(coreMD5(str2binl(str))) }
    function hexMD5w(str) { return binl2hex(coreMD5(strw2binl(str))) }
    function b64MD5(str) { return binl2b64(coreMD5(str2binl(str))) }
    function b64MD5w(str) { return binl2b64(coreMD5(strw2binl(str))) }
    /* Backward compatibility */
    function calcMD5(str) { return binl2hex(coreMD5(str2binl(str))) }


    /*
    * Library functions to assist in integration using SIM method
    *
    * Main Interfaces:
    *
    * function InsertFP (loginid, txnkey, amount, sequence) - Insert HTML form elements required for SIM
    * function CalculateFP (loginid, txnkey, amount, sequence, tstamp) - Returns Fingerprint.
    * function GetSecondsSince1970 () - Returns the number of seconds since 1970 Jan 1 UTC.
    *
    * DISCLAIMER:
    This code is distributed in the hope that it will be useful, but without any warranty;
    without even the implied warranty of merchantability or fitness for a particular purpose.
    *
    */

    function binl2byt(binarray) {
        var hex_tab = "0123456789abcdef";
        var bytarray = new Array(binarray.length * 4);
        var str = "";
        for (var i = 0; i < binarray.length * 4; i++) {
            bytarray[i] = (binarray[i >> 2] >> ((i % 4) * 8 + 4) & 0xF) << 4 |
		   binarray[i >> 2] >> ((i % 4) * 8) & 0xF;
        }
        return bytarray;
    }


    function bytarray2word(barray) {

        var blks = new Array(barray.length / 4);
        for (var i = 0; i < blks.length; i++) blks[i] = 0
        for (var i = 0; i < barray.length; i++)
            blks[i >> 2] |= (barray[i] & 0xFF) << ((i % 4) * 8)
        //blks[i>>2] |= 0x80 << ((i%4) * 8)
        //blks[nblk*16-2] = barray.length * 8
        return blks
    }

    function bytarray2binl(barray) {

        var nblk = ((barray.length + 8) >> 6) + 1 // number of 16-word blocks
        var blks = new Array(nblk * 16)
        for (var i = 0; i < nblk * 16; i++) blks[i] = 0
        for (var i = 0; i < barray.length; i++)
            blks[i >> 2] |= (barray[i] & 0xFF) << ((i % 4) * 8)
        blks[i >> 2] |= 0x80 << ((i % 4) * 8)
        blks[nblk * 16 - 2] = barray.length * 8
        return blks
    }

    function b_calcMD5(barray) { return coreMD5(bytarray2binl(barray)) }


    function HMAC(key, text) {
        var hkey;
        var ipad = new Array(64);
        var opad = new Array(64);
        var idata;
        var odata;

        idata = new Array(64 + text.length);
        odata = new Array(64 + 16);
        if (key.length > 64) {
            hkey = calcMD5(key);
        }
        else
            hkey = key;

        for (i = 0; i < 64; i++) {
            idata[i] = ipad[i] = 0x36;
            odata[i] = opad[i] = 0x5C;
        }

        for (i = 0; i < hkey.length; i++) {
            ipad[i] ^= hkey.charCodeAt(i);
            opad[i] ^= hkey.charCodeAt(i);

            idata[i] = ipad[i] & 0xFF;
            odata[i] = opad[i] & 0xFF;
        }

        for (i = 0; i < text.length; i++) {
            idata[64 + i] = text.charCodeAt(i) & 0xFF;
        }

        var innerhashout = binl2byt(b_calcMD5(idata));
        for (i = 0; i < 16; i++) {
            odata[64 + i] = innerhashout[i];
        }


        return binl2hex(b_calcMD5(odata));
    }

    /* Return the number of seconds elapsed since Jan 1, 1970 UTC */
    function GetSecondsSince1970() {
        var d = new Date();
        var secs = Math.floor(d.getTime() / 1000);

        return (secs);
    }

    /* Returns the fingerprint */
    /* Use this when you need control of HTML output */
    /* Currency is optional. If you send x_currency_code then you must pass the same currency code here */
    function CalculateFP(loginid, txnkey, amount, sequence, tstamp, currency) {

        if (currency == null) currency = "";

        var fingerprint = HMAC(txnkey, loginid + "^" + sequence + "^" + tstamp + "^" + amount + "^" + currency);

        return (fingerprint);

    }

    /* Insert the HTML form elements needed for SIM */
    /* currency is optional. */
    var tstamp;
    function InsertFP(loginid, txnkey, amount, sequence, currency) {
        tstamp = GetSecondsSince1970();

        //***   for testing only:   ***********************************
        // var tstamp = 1050143570;

        var fingerprint = CalculateFP(loginid, txnkey, amount, sequence, tstamp, currency);

        document.getElementById('x_fp_hash').value = fingerprint;
        document.getElementById('x_fp_timestamp').value = tstamp;
        
        return (0);

    }