Single function implementation of MD5 in Javascript

md5

function md5(str) {
    var i, j,
        bytes = [],
        words = [],
        hex = [];

    var Y = [7, 12, 17, 22, 5, 9, 14, 20, 4, 11, 16, 23, 6, 10, 15, 21];

    var Z = [0xd76aa478, 0xe8c7b756, 0x242070db, 0xc1bdceee,
        0xf57c0faf, 0x4787c62a, 0xa8304613, 0xfd469501,
        0x698098d8, 0x8b44f7af, 0xffff5bb1, 0x895cd7be,
        0x6b901122, 0xfd987193, 0xa679438e, 0x49b40821,

        0xf61e2562, 0xc040b340, 0x265e5a51, 0xe9b6c7aa,
        0xd62f105d, 0x02441453, 0xd8a1e681, 0xe7d3fbc8,
        0x21e1cde6, 0xc33707d6, 0xf4d50d87, 0x455a14ed,
        0xa9e3e905, 0xfcefa3f8, 0x676f02d9, 0x8d2a4c8a,

        0xfffa3942, 0x8771f681, 0x6d9d6122, 0xfde5380c,
        0xa4beea44, 0x4bdecfa9, 0xf6bb4b60, 0xbebfbc70,
        0x289b7ec6, 0xeaa127fa, 0xd4ef3085, 0x04881d05,
        0xd9d4d039, 0xe6db99e5, 0x1fa27cf8, 0xc4ac5665,

        0xf4292244, 0x432aff97, 0xab9423a7, 0xfc93a039,
        0x655b59c3, 0x8f0ccc92, 0xffeff47d, 0x85845dd1,
        0x6fa87e4f, 0xfe2ce6e0, 0xa3014314, 0x4e0811a1,
        0xf7537e82, 0xbd3af235, 0x2ad7d2bb, 0xeb86d391];

    // Convert string to UTF-8
    str = unescape(encodeURIComponent(str));

    // Convert string to bytes
    for (i = 0; i < str.length; i++) {
        bytes.push(str.charCodeAt(i) & 0xFF);
    }

    // Convert bytes to words
    for (i = 0, j = 0; i < bytes.length; i++, j += 8) {
        words[j >>> 5] |= bytes[i] << (24 - j % 32);
    }

    var m = words,
        l = str.length * 8,
        a = 0x67452301,
        b = 0xefcdab89,
        c = 0x98badcfe,
        d = 0x10325476;

    // Swap endian
    for (i = 0; i < m.length; i++) {
        m[i] = ((m[i] << 8) | (m[i] >>> 24)) & 0x00FF00FF |
            ((m[i] << 24) | (m[i] >>> 8)) & 0xFF00FF00;
    }

    // Padding
    m[l >>> 5] |= 0x80 << (l % 32);
    m[(((l + 64) >>> 9) << 4) + 14] = l;

    // Calculate
    for (i = 0; i < m.length; i += 16) {
        var aa = a,
            bb = b,
            cc = c,
            dd = d;

        var tmp, n, x, y, z;

        for (j = 0; j < 64; j++) {
            z = Z[j];
            if (j < 16) {
                x = m[i + j];
                y = Y[j % 4];
                n = a + (b & c | ~b & d) + (x >>> 0) + z;
            }
            else if (j < 32) {
                x = m[i + (5 * j + 1) % 16];
                y = Y[4 + j % 4];
                n = a + (b & d | c & ~d) + (x >>> 0) + z;
            }
            else if (j < 48) {
                x = m[i + (3 * j + 5) % 16];
                y = Y[8 + j % 4];
                n = a + (b ^ c ^ d) + (x >>> 0) + z;
            }
            else {
                x = m[i + (7 * j) % 16];
                y = Y[12 + j % 4];
                n = a + (c ^ (b | ~d)) + (x >>> 0) + z;
            }

            a = ((n << y) | (n >>> (32 - y))) + b;

            // Rotate
            tmp = d;
            d = c;
            c = b;
            b = a;
            a = tmp;
        }

        a = (a + aa) >>> 0;
        b = (b + bb) >>> 0;
        c = (c + cc) >>> 0;
        d = (d + dd) >>> 0;
    }

    words = [a, b, c, d];

    // Swap endian
    for (i = 0; i < words.length; i++) {
        words[i] = ((words[i] << 8) | (words[i] >>> 24)) & 0x00FF00FF |
            ((words[i] << 24) | (words[i] >>> 8)) & 0xFF00FF00;
    }

    // Convert words to bytes
    for (bytes = [], i = 0; i < words.length * 32; i += 8) {
        bytes.push((words[i >>> 5] >>> (24 - i % 32)) & 0xFF);
    }

    // Convert bytes to hex
    for (hex = [], i = 0; i < bytes.length; i++) {
        hex.push((bytes[i] >>> 4).toString(16));
        hex.push((bytes[i] & 0xF).toString(16));
    }
    
    return hex.join('');
};