/*   
 *   A   JavaScript   implementation   of   the   Secure   Hash   Algorithm,   SHA-1,   as   defined   
 *   in   FIPS   PUB   180-1   
 *   Version   2.1-BETA   Copyright   Paul   Johnston   2000   -   2002.   
 *   Other   contributors:   Greg   Holt,   Andrew   Kepert,   Ydnar,   Lostinet   
 *   Distributed   under   the   BSD   License   
 *   See   http://pajhome.org.uk/crypt/md5   for   details.   
 */
/*   
 *   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_sha1(s) {
    return binb2hex(core_sha1(str2binb(s), s.length * chrsz));
}

function b64_sha1(s) {
    return binb2b64(core_sha1(str2binb(s), s.length * chrsz));
}

function str_sha1(s) {
    return binb2str(core_sha1(str2binb(s), s.length * chrsz));
}

function hex_hmac_sha1(key, data) {
    return binb2hex(core_hmac_sha1(key, data));
}

function b64_hmac_sha1(key, data) {
    return binb2b64(core_hmac_sha1(key, data));
}

function str_hmac_sha1(key, data) {
    return binb2str(core_hmac_sha1(key, data));
}

/*   
 *   Perform   a   simple   self-test   to   see   if   the   VM   is   working   
 */
function sha1_vm_test() {
    return hex_sha1("abc") == "a9993e364706816aba3e25717850c26c9cd0d89d";
}

/*   
 *   Calculate   the   SHA-1   of   an   array   of   big-endian   words,   and   a   bit   length   
 */
function core_sha1(x, len) {
    /*   append   padding   */
    x[len >> 5] |= 0x80 << (24 - len % 32);
    x[((len + 64 >> 9) << 4) + 15] = len;

    var w = Array(80);
    var a = 1732584193;
    var b = -271733879;
    var c = -1732584194;
    var d = 271733878;
    var e = -1009589776;

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

        for (var j = 0; j < 80; j++) {
            if (j < 16) w[j] = x[i + j];
            else w[j] = rol(w[j - 3] ^ w[j - 8] ^ w[j - 14] ^ w[j - 16], 1);
            var t = safe_add(safe_add(rol(a, 5), sha1_ft(j, b, c, d)), safe_add(safe_add(e, w[j]), sha1_kt(j)));
            e = d;
            d = c;
            c = rol(b, 30);
            b = a;
            a = t;
        }

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

}

/*   
 *   Perform   the   appropriate   triplet   combination   function   for   the   current   
 *   iteration   
 */
function sha1_ft(t, b, c, d) {
    if (t < 20) return (b & c) | ((~b) & d);
    if (t < 40) return b ^ c ^ d;
    if (t < 60) return (b & c) | (b & d) | (c & d);
    return b ^ c ^ d;
}

/*   
 *   Determine   the   appropriate   additive   constant   for   the   current   iteration   
 */
function sha1_kt(t) {
    return (t < 20) ? 1518500249 : (t < 40) ? 1859775393 : (t < 60) ? -1894007588 : -899497514;
}

/*   
 *   Calculate   the   HMAC-SHA1   of   a   key   and   some   data   
 */
function core_hmac_sha1(key, data) {
    var bkey = str2binb(key);
    if (bkey.length > 16) bkey = core_sha1(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_sha1(ipad.concat(str2binb(data)), 512 + data.length * chrsz);
    return core_sha1(opad.concat(hash), 512 + 160);
}

/*   
 *   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));
}

/*   
 *   Convert   an   8-bit   or   16-bit   string   to   an   array   of   big-endian   words   
 *   In   8-bit   function,   characters   >255   have   their   hi-byte   silently   ignored.   
 */
function str2binb(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) << (24 - i % 32);
    return bin;
}

/*   
 *   Convert   an   array   of   big-endian   words   to   a   string   
 */
function binb2str(bin) {
    var str = "";
    var mask = (1 << chrsz) - 1;
    for (var i = 0; i < bin.length * 32; i += chrsz)
    str += String.fromCharCode((bin[i >> 5] >>> (24 - i % 32)) & mask);
    return str;
}

/*   
 *   Convert   an   array   of   big-endian   words   to   a   hex   string.   
 */
function binb2hex(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] >> ((3 - i % 4) * 8 + 4)) & 0xF) + hex_tab.charAt((binarray[i >> 2] >> ((3 - i % 4) * 8)) & 0xF);
    }
    return str;
}

/*   
 *   Convert   an   array   of   big-endian   words   to   a   base-64   string   
 */
function binb2b64(binarray) {
    var tab = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
    var str = "";
    for (var i = 0; i < binarray.length * 4; i += 3) {
        var triplet = (((binarray[i >> 2] >> 8 * (3 - i % 4)) & 0xFF) << 16) | (((binarray[i + 1 >> 2] >> 8 * (3 - (i + 1) % 4)) & 0xFF) << 8) | ((binarray[i + 2 >> 2] >> 8 * (3 - (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;
}