PHPRPC Code

/********************************************
  PowMod BigInt library
  Author: Alexander Valyalkin (valyala@tut.by)
*********************************************/

function mul(a, b) {
    var n = a.length, m = b.length, nm = n + m, i, j, c = Array(n);
    for (i = 0; i < nm; i++) c[i] = 0;
    for (i = 0; i < n; i++) {
        for (j = 0; j < m; j++) {
            c[i + j] += a[i] * b[j];
            c[i + j + 1] += (c[i + j] >> 16) & 0xffff;
            c[i + j] &= 0xffff;
        }
    }
    return c;
}

function div(a, b, is_mod) {
    var n = a.length, m = b.length, i, j, d, tmp, qq, rr, c = Array();
    d = Math.floor(0x10000 / (b[m - 1] + 1));
    a = mul(a, [d]);
    b = mul(b, [d]);
    for (j = n - m; j >= 0; j--) {
        tmp = a[j + m] * 0x10000 + a[j + m - 1];
        rr = tmp % b[m - 1];
        qq = Math.round((tmp - rr) / b[m - 1]);
        if (qq == 0x10000 || (m > 1 && qq * b[m - 2] > 0x10000 * rr + a[j + m - 2])) {
            qq--;
            rr += b[m - 1];
            if (rr < 0x10000 && qq * b[m - 2] > 0x10000 * rr + a[j + m - 2]) qq--;
        }
        for (i = 0; i < m; i++) {
            tmp = i + j;
            a[tmp] -= b[i] * qq;
            a[tmp + 1] += Math.floor(a[tmp] / 0x10000);
            a[tmp] &= 0xffff;
        }
        c[j] = qq;
        if (a[tmp + 1] < 0) {
            c[j]--;
            for (i = 0; i < m; i++) {
                tmp = i + j;
                a[tmp] += b[i];
                if (a[tmp] > 0xffff) {
                    a[tmp + 1]++;
                    a[tmp] &= 0xffff;
                }
            }
        }
    }
    if (!is_mod) return c;
    b = Array();
    for (i = 0; i < m; i++) b[i] = a[i];
    return div(b, [d]);
}

function pow_mod(a, b, c) {
    var n = b.length, p = [1], i, j, tmp;
    for (i = 0; i < n - 1; i++) {
        tmp = b[i];
        for (j = 0; j < 0x10; j++) {
            if (tmp & 1) p = div(mul(p, a), c, 1);
            tmp >>= 1;
            a = div(mul(a, a), c, 1);
        }
    }
    tmp = b[i];
    while (tmp) {
        if (tmp & 1) p = div(mul(p, a), c, 1);
        tmp >>= 1;
        a = div(mul(a, a), c, 1);
    }
    return p;
}

/*************************************************************/

function zerofill(str, num) {
    var n = num - str.toString().length, i, s = '';
    for (i = 0; i < n; i++) s += '0';
    return s + str;
}

function dec2num(str) {
    var n = str.length, a = [0], i, j, m;
    n += 4 - (n % 4);
    str = zerofill(str, n);
    n >>= 2;
    for (i = 0; i < n; i++) {
        a = mul(a, [10000]);
        a[0] += parseInt(str.substring(4 * i, 4 * (i + 1)), 10);
        m = a.length;
        j = a[m] = 0;
        while (j < m && a[j] > 0xffff) {
            a[j++] &= 0xffff;
            a[j]++;
        }
        while (a.length > 1 && !a[a.length - 1]) a.length--;
    }
    return a;
}

function num2dec(a) {
    var n = 2 * a.length, b = Array(), i;
    for (i = 0; i < n; i++) {
        b[i] = zerofill(div(a, [10000], 1)[0], 4);
        a = div(a, [10000]);
    }
    while (b.length > 1 && !parseInt(b[b.length - 1], 10)) b.length--;
    n = b.length - 1;
    b[n] = parseInt(b[n], 10);
    b = b.reverse().join('');
    return b;
}

/*********************************************************/

function is_decimal(str) {
    var n = str.length;
    if (!n) return 0;
    str = str.split('');
    while (n--) if (isNaN(parseInt(str[n], 10))) return 0;
    return 1;
}

/*************************************************************/

function str2num(str) {
    var len = str.length;
    if (len & 1) {
        str = "\0" + str;
        len++;
    }
    len >>= 1;
    var result = Array();
    for (var i = 0; i < len; i++) {
        result[len - i - 1] = str.charCodeAt(i << 1) << 8 | str.charCodeAt((i << 1) + 1);
    }
    return result;
}

function num2str(num) {
    var n = num.length;
    var s = Array();
    for (var i = 0; i < n; i++) {
        s[n - i - 1] = String.fromCharCode(num[i] >> 8 & 0xff, num[i] & 0xff);
    }
    return s.join('');
}

function rand(n, s) {
    var lowBitMasks = new Array(0x0000, 0x0001, 0x0003, 0x0007,
                                0x000f, 0x001f, 0x003f, 0x007f,
                                0x00ff, 0x01ff, 0x03ff, 0x07ff,
                                0x0fff, 0x1fff, 0x3fff, 0x7fff);

    var r = n % 16;
    var q = Math.floor(n / 16);
    var result = Array();
    for (var i = 0; i < q; i++) {
        result[i] = Math.floor(Math.random() * 0xffff);
    }
    if (r != 0) {
        result[q] = Math.floor(Math.random() * lowBitMasks[r]);
        if (s) {
            result[q] |= 1 << (r - 1);
        }
    }
    else if (s) {
        result[q - 1] |= 0x8000;
    }
    return result;
}