khash.js

/**
 * Secure Hash Algorithm (SHA1)
 * http://www.webtoolkit.info/
 **/
function SHA1(msg) {
    function rotate_left(n, s) {
        var t4 = (n << s) | (n >>> (32 - s));
        return t4;
    }

    function lsb_hex(val) {
        var str = '';
        var i;
        var vh;
        var vl;
        for (i = 0; i <= 6; i += 2) {
            vh = (val >>> (i * 4 + 4)) & 0x0f;
            vl = (val >>> (i * 4)) & 0x0f;
            str += vh.toString(16) + vl.toString(16);
        }
        return str;
    }

    function cvt_hex(val) {
        var str = '';
        var i;
        var v;
        for (i = 7; i >= 0; i--) {
            v = (val >>> (i * 4)) & 0x0f;
            str += v.toString(16);
        }
        return str;
    }

    function Utf8Encode(string) {
        string = string.replace(/\r\n/g, '\n');
        var utftext = '';
        for (var n = 0; n < string.length; n++) {
            var c = string.charCodeAt(n);
            if (c < 128) {
                utftext += String.fromCharCode(c);
            } else if ((c > 127) && (c < 2048)) {
                utftext += String.fromCharCode((c >> 6) | 192);
                utftext += String.fromCharCode((c & 63) | 128);
            } else {
                utftext += String.fromCharCode((c >> 12) | 224);
                utftext += String.fromCharCode(((c >> 6) & 63) | 128);
                utftext += String.fromCharCode((c & 63) | 128);
            }
        }
        return utftext;
    }
    var blockstart;
    var i, j;
    var W = new Array(80);
    var H0 = 0x67452301;
    var H1 = 0xEFCDAB89;
    var H2 = 0x98BADCFE;
    var H3 = 0x10325476;
    var H4 = 0xC3D2E1F0;
    var A, B, C, D, E;
    var temp;
    msg = Utf8Encode(msg);
    var msg_len = msg.length;
    var word_array = new Array();
    for (i = 0; i < msg_len - 3; i += 4) {
        j = msg.charCodeAt(i) << 24 | msg.charCodeAt(i + 1) << 16 |
            msg.charCodeAt(i + 2) << 8 | msg.charCodeAt(i + 3);
        word_array.push(j);
    }
    switch (msg_len % 4) {
        case 0:
            i = 0x080000000;
            break;
        case 1:
            i = msg.charCodeAt(msg_len - 1) << 24 | 0x0800000;
            break;
        case 2:
            i = msg.charCodeAt(msg_len - 2) << 24 | msg.charCodeAt(msg_len - 1) << 16 | 0x08000;
            break;
        case 3:
            i = msg.charCodeAt(msg_len - 3) << 24 | msg.charCodeAt(msg_len - 2) << 16 | msg.charCodeAt(msg_len - 1) << 8 | 0x80;
            break;
    }
    word_array.push(i);
    while ((word_array.length % 16) != 14) word_array.push(0);
    word_array.push(msg_len >>> 29);
    word_array.push((msg_len << 3) & 0x0ffffffff);
    for (blockstart = 0; blockstart < word_array.length; blockstart += 16) {
        for (i = 0; i < 16; i++) W[i] = word_array[blockstart + i];
        for (i = 16; i <= 79; i++) W[i] = rotate_left(W[i - 3] ^ W[i - 8] ^ W[i - 14] ^ W[i - 16], 1);
        A = H0;
        B = H1;
        C = H2;
        D = H3;
        E = H4;
        for (i = 0; i <= 19; i++) {
            temp = (rotate_left(A, 5) + ((B & C) | (~B & D)) + E + W[i] + 0x5A827999) & 0x0ffffffff;
            E = D;
            D = C;
            C = rotate_left(B, 30);
            B = A;
            A = temp;
        }
        for (i = 20; i <= 39; i++) {
            temp = (rotate_left(A, 5) + (B ^ C ^ D) + E + W[i] + 0x6ED9EBA1) & 0x0ffffffff;
            E = D;
            D = C;
            C = rotate_left(B, 30);
            B = A;
            A = temp;
        }
        for (i = 40; i <= 59; i++) {
            temp = (rotate_left(A, 5) + ((B & C) | (B & D) | (C & D)) + E + W[i] + 0x8F1BBCDC) & 0x0ffffffff;
            E = D;
            D = C;
            C = rotate_left(B, 30);
            B = A;
            A = temp;
        }
        for (i = 60; i <= 79; i++) {
            temp = (rotate_left(A, 5) + (B ^ C ^ D) + E + W[i] + 0xCA62C1D6) & 0x0ffffffff;
            E = D;
            D = C;
            C = rotate_left(B, 30);
            B = A;
            A = temp;
        }
        H0 = (H0 + A) & 0x0ffffffff;
        H1 = (H1 + B) & 0x0ffffffff;
        H2 = (H2 + C) & 0x0ffffffff;
        H3 = (H3 + D) & 0x0ffffffff;
        H4 = (H4 + E) & 0x0ffffffff;
    }
    var temp = cvt_hex(H0) + cvt_hex(H1) + cvt_hex(H2) + cvt_hex(H3) + cvt_hex(H4);

    return temp.toLowerCase();
}

//base85 Ascii85 Original
function decode(str) {
    str = str.replace(/\s/g, "");
    str = str.replace(/z/g, "!!!!!");
    str = str.replace(/y/g, "+<VdL/");

    // Pad the end of the string so it's a multiple of 5
    var padding = 5 - (str.length % 5);
    if (str.length % 5 === 0) {
        padding = 0;
    }
    str += "u".repeat(padding);

    var num = 0;
    var ret = "";

    // Foreach 5 chars, convert it to an integer
    while (num * 5 < str.length) {
        var chunk = str.substring(num * 5, num * 5 + 5);
        var tmp = 0;

        for (var i = 0; i < chunk.length; i++) {
            var item = chunk.charCodeAt(i);
            tmp *= 85;
            tmp += item - 33;
        }

        // Convert the integer in to a string
        ret += String.fromCharCode((tmp >> 24) & 0xFF, (tmp >> 16) & 0xFF, (tmp >> 8) & 0xFF, tmp & 0xFF);

        num++;
    }

    // Remove any padding we had to add
    ret = ret.substring(0, ret.length - padding);

    return ret;
}

//Kount KHASH
const khash = {
    hash: function(data, len) {

        const decodedConfigKey = decode(process.env.CONFIG_KEY);

        const a = '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ';
        const r = SHA1(`${data}.${decodedConfigKey}`);
        let c = data.toString().substr(0, 6);
        if (len > 17) {
            len = 17;
        }
        const limit = 2 * len;
        for (let i = 0; i < limit; i += 2) {
            c += a[parseInt(r.substr(i, 7), 16) % 36];
        }

        return c;
    }
}

module.exports = khash;