md5.js

/**
 * MD5 Hash Class.
 */
export default class MD5 {
    /**
     * Constructs an Hash Class.
     */
    constructor() {
        this.hexTable = '0123456789abcdef'.split('');
        /* eslint-disable no-magic-numbers */
        this.unicodeArray = [
            [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15],
            [1, 6, 11, 0, 5, 10, 15, 4, 9, 14, 3, 8, 13, 2, 7, 12],
            [5, 8, 11, 14, 1, 4, 7, 10, 13, 0, 3, 6, 9, 12, 15, 2],
            [0, 7, 14, 5, 12, 3, 10, 1, 8, 15, 6, 13, 4, 11, 2, 9]
        ];
        this.sineArray = [
            [7, 12, 17, 22, 7, 12, 17, 22, 7, 12, 17, 22, 7, 12, 17, 22],
            [5, 9, 14, 20, 5, 9, 14, 20, 5, 9, 14, 20, 5, 9, 14, 20],
            [4, 11, 16, 23, 4, 11, 16, 23, 4, 11, 16, 23, 4, 11, 16, 23],
            [6, 10, 15, 21, 6, 10, 15, 21, 6, 10, 15, 21, 6, 10, 15, 21]
        ];
        this.tableArray = [
            [
                -680876936, -389564586, 606105819, -1044525330,
                -176418897, 1200080426, -1473231341, -45705983,
                1770035416, -1958414417, -42063, -1990404162,
                1804603682, -40341101, -1502002290, 1236535329
            ],
            [
                -165796510, -1069501632, 643717713, -373897302,
                -701558691, 38016083, -660478335, -405537848,
                568446438, -1019803690, -187363961, 1163531501,
                -1444681467, -51403784, 1735328473, -1926607734
            ],
            [
                -378558, -2022574463, 1839030562, -35309556,
                -1530992060, 1272893353, -155497632, -1094730640,
                681279174, -358537222, -722521979, 76029189,
                -640364487, -421815835, 530742520, -995338651
            ],
            [
                -198630844, 1126891415, -1416354905, -57434055,
                1700485571, -1894986606, -1051523, -2054922799,
                1873313359, -30611744, -1560198380, 1309151649,
                -145523070, -1120210379, 718787259, -343485551
            ]
        ];
        /* eslint-enable no-magic-numbers */

        this.functionArray = [this.ff.bind(this), this.gg.bind(this), this.hh.bind(this), this.ii.bind(this)];
    }

    /**
     * Start MD5 Hashing.
     *
     * @param {string} string String to hash.
     *
     * @returns {string} Hashed string.
     */
    transpile(string) {
        return this.hex(this.md5(string));
    }

    /**
     * Hexes an MD5 String.
     *
     * @param {string} md5String MD5 String to hex.
     *
     * @returns {string} Returns hexed string.
     */
    hex(md5String) {
        let i = 0;

        for (i; i < md5String.length; i++) {
            md5String[i] = this.rhex(md5String[i]);
        }

        return md5String.join('');
    }

    /**
     * Real hexing function.
     *
     * @param {string} character An character of an string to hex.
     *
     * @returns {string} Returns hexed char.
     */
    rhex(character) {
        const bit = 8;
        const halfBit = 4;
        const hex = 0x0F;
        let i = 0;
        let hexString = '', firstHex, secondHex;

        for (i; i < halfBit; i++) {
            firstHex = this.hexTable[(character >> (i * bit + halfBit)) & hex];
            secondHex = this.hexTable[(character >> (i * bit)) & hex];

            hexString += `${firstHex}${secondHex}`;
        }

        return hexString;
    }

    /**
     * Converts string to MD5.
     *
     * @param {string} string String to convert.
     *
     * @returns {string} MD5 of string.
     */
    md5(string) {
        /* eslint-disable no-magic-numbers */
        const hexKey = 0x80;
        let tail = [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0];
        let state = [1732584193, -271733879, -1732584194, 271733878];
        let mdString = string;
        let stringLength = mdString.length, i;

        for (i = 64; i <= mdString.length; i += 64) {
            state = this.md5Crypt(state, this.md5blk(mdString.substring(i - 64, i)));
        }

        mdString = mdString.substring(i - 64);

        for (i = 64; i < mdString.length; i++) {
            tail[i >> 2] |= mdString.charCodeAt(i) << ((i % 4) << 3);
        }

        tail[i >> 2] |= hexKey << ((i % 4) << 3);

        if (i > 55) {
            state = this.md5Crypt(state, tail);

            for (i = 0; i < 16; i++) {
                tail[i] = 0;
            }
        }

        tail[14] = stringLength * 8;

        state = this.md5Crypt(state, tail);

        return state;
        /* eslint-enable no-magic-numbers */
    }

    /**
     * Chunkwise unicode encryption.
     *
     * @param {string} string Chunk to encrypt.
     *
     * @returns {string} Encrypted chunk.
     */
    md5blk(string) {
        /* eslint-disable no-magic-numbers */
        let md5blks = [], i, firstPart, secondPart, thirdPart, fourthPart;

        for (i = 0; i < 64; i += 4) {
            firstPart = string.charCodeAt(i);
            secondPart = string.charCodeAt(i + 1) << 8;
            thirdPart = string.charCodeAt(i + 2) << 16;
            fourthPart = string.charCodeAt(i + 3) << 24;
            md5blks[i >> 2] = `${firstPart}${secondPart}${thirdPart}${fourthPart}`;
        }

        return md5blks;
        /* eslint-enable no-magic-numbers */
    }

    /**
     * Encrypt Chunk.
     *
     * @param {mixed} state State array.
     * @param {string} unicode Unicode encrypted Chunk.
     *
     * @returns {mixed} Changed state array.
     */
    md5Crypt(state, unicode) {
        /* eslint-disable no-magic-numbers */
        let a = state[0], b = state[1], c = state[2], d = state[3];
        let i, k;

        for (i = 0; i < 4; i++) {
            for (k = 0; k < 16; k += 4) {
                a = this.functionArray[i](
                    a, b, c, d,
                    unicode[this.unicodeArray[i][k]],
                    this.sineArray[i][k],
                    this.tableArray[i][k]
                );
                d = this.functionArray[i](
                    d, a, b, c,
                    unicode[this.unicodeArray[i][k + 1]],
                    this.sineArray[i][k + 1],
                    this.tableArray[i][k + 1]
                );
                c = this.functionArray[i](
                    c, d, a, b,
                    unicode[this.unicodeArray[i][k + 2]],
                    this.sineArray[i][k + 2],
                    this.tableArray[i][k + 2]
                );
                b = this.functionArray[i](
                    b, c, d, a,
                    unicode[this.unicodeArray[i][k + 3]],
                    this.sineArray[i][k + 3],
                    this.tableArray[i][k + 3]
                );
            }
        }

        state[0] = this.add32(a, state[0]);
        state[1] = this.add32(b, state[1]);
        state[2] = this.add32(c, state[2]);
        state[3] = this.add32(d, state[3]);

        return state;
        /* eslint-enable no-magic-numbers */
    }

    /**
     * FF Encryption.
     *
     * @param {string} a Char state a.
     * @param {string} b Char state b.
     * @param {string} c Char state c.
     * @param {string} d Char state d.
     * @param {string} x Unicode String.
     * @param {number} s Sine number.
     * @param {number} t Table number.
     *
     * @returns {string} String to return.
     */
    ff(a, b, c, d, x, s, t) {
        return this.cmn((b & c) | ((~b) & d), a, b, x, s, t);
    }

    /**
     * GG Encryption.
     *
     * @param {string} a Char state a.
     * @param {string} b Char state b.
     * @param {string} c Char state c.
     * @param {string} d Char state d.
     * @param {string} x Unicode String.
     * @param {number} s Sine number.
     * @param {number} t Table number.
     *
     * @returns {string} String to return.
     */
    gg(a, b, c, d, x, s, t) {
        return this.cmn((b & d) | (c & (~d)), a, b, x, s, t);
    }

    /**
     * HH Encryption.
     *
     * @param {string} a Char state a.
     * @param {string} b Char state b.
     * @param {string} c Char state c.
     * @param {string} d Char state d.
     * @param {string} x Unicode String.
     * @param {number} s Sine number.
     * @param {number} t Table number.
     *
     * @returns {string} String to return.
     */
    hh(a, b, c, d, x, s, t) {
        return this.cmn(b ^ c ^ d, a, b, x, s, t);
    }

    /**
     * II Encryption.
     *
     * @param {string} a Char state a.
     * @param {string} b Char state b.
     * @param {string} c Char state c.
     * @param {string} d Char state d.
     * @param {string} x Unicode String.
     * @param {number} s Sine number.
     * @param {number} t Table number.
     *
     * @returns {string} String to return.
     */
    ii(a, b, c, d, x, s, t) {
        return this.cmn(c ^ (b | (~d)), a, b, x, s, t);
    }

    /**
     * CMN Encryption.
     *
     * @param {string} q Char state q.
     * @param {string} a Char state a.
     * @param {string} b Char state b.
     * @param {string} x Unicode String.
     * @param {number} s Sine number.
     * @param {number} t Table number.
     *
     * @returns {string} String to return.
     */
    cmn(q, a, b, x, s, t) {
        /* eslint-disable no-magic-numbers */
        let c = a;

        c = this.add32(this.add32(a, q), this.add32(x, t));

        return this.add32((c << s) | (c >>> (32 - s)), b);
        /* eslint-enable no-magic-numbers */
    }

    /**
     * Adds 32 bit.
     *
     * @param {string} a Char state a.
     * @param {string} b Char state b.
     *
     * @returns {string} String to return.
     */
    add32(a, b) {
        let hex = 0xFFFFFFFF;

        return (a + b) & hex;
    }
}