scrypt_cooked.js

var scrypt = (function () {
    var exports = {};

    //---------------------------------------------------------------------------
    // Horrifying UTF-8 and hex codecs

    function encode_utf8(s) {
	return encode_latin1(unescape(encodeURIComponent(s)));
    }

    function encode_latin1(s) {
	var result = new Uint8Array(s.length);
	for (var i = 0; i < s.length; i++) {
	    var c = s.charCodeAt(i);
	    if ((c & 0xff) !== c) throw {message: "Cannot encode string in Latin1", str: s};
	    result[i] = (c & 0xff);
	}
	return result;
    }

    function decode_utf8(bs) {
	return decodeURIComponent(escape(decode_latin1(bs)));
    }

    function decode_latin1(bs) {
	var encoded = [];
	for (var i = 0; i < bs.length; i++) {
	    encoded.push(String.fromCharCode(bs[i]));
	}
	return encoded.join('');
    }

    function to_hex(bs) {
	var encoded = [];
	for (var i = 0; i < bs.length; i++) {
	    encoded.push("0123456789abcdef"[(bs[i] >> 4) & 15]);
	    encoded.push("0123456789abcdef"[bs[i] & 15]);
	}
	return encoded.join('');
    }

    //---------------------------------------------------------------------------

    function injectBytes(bs, leftPadding) {
	var p = leftPadding || 0;
	var address = scrypt_raw._malloc(bs.length + p);
	scrypt_raw.HEAPU8.set(bs, address + p);
	for (var i = address; i < address + p; i++) {
	    scrypt_raw.HEAPU8[i] = 0;
	}
	return address;
    }

    function check_injectBytes(function_name, what, thing, expected_length, leftPadding) {
	check_length(function_name, what, thing, expected_length);
	return injectBytes(thing, leftPadding);
    }

    function extractBytes(address, length) {
	var result = new Uint8Array(length);
	result.set(scrypt_raw.HEAPU8.subarray(address, address + length));
	return result;
    }

    //---------------------------------------------------------------------------

    function check(function_name, result) {
	if (result !== 0) {
	    throw {message: "scrypt_raw." + function_name + " signalled an error"};
	}
    }

    function check_length(function_name, what, thing, expected_length) {
	if (thing.length !== expected_length) {
	    throw {message: "scrypt." + function_name + " expected " +
	           expected_length + "-byte " + what + " but got length " + thing.length};
	}
    }

    function Target(length) {
	this.length = length;
	this.address = scrypt_raw._malloc(length);
    }

    Target.prototype.extractBytes = function (offset) {
	var result = extractBytes(this.address + (offset || 0), this.length - (offset || 0));
	scrypt_raw._free(this.address);
	this.address = null;
	return result;
    };

    function free_all(addresses) {
	for (var i = 0; i < addresses.length; i++) {
	    scrypt_raw._free(addresses[i]);
	}
    }

    //---------------------------------------------------------------------------

    function random_bytes(count) {
	var bs = new Uint8Array(count);
	if(typeof(window.crypto) !== "undefined") {
	    if(typeof(window.crypto.getRandomValues) !== "undefined") {
	    	window.crypto.getRandomValues(bs);
	    	return bs;
	    }
	}
	if(typeof(window.msCrypto) !== "undefined") {
	    if(typeof(window.msCrypto.getRandomValues) !== "undefined") {
	    	window.msCrypto.getRandomValues(bs);
	    	return bs;
	    }
	}
	throw { message: "No suitable random number generator found!"};
    }

    function crypto_scrypt(passwd, salt, n, r, p, buflen) {
	var buf = new Target(buflen);
	var pa = injectBytes(passwd);
	var sa = injectBytes(salt);
	check("_crypto_scrypt",
	      scrypt_raw._crypto_scrypt(pa, passwd.length,
					sa, salt.length,
					n, 0, // 64 bits; zero upper half
					r,
					p,
					buf.address, buf.length));
	free_all([pa, sa]);
	return buf.extractBytes();
    }

    //---------------------------------------------------------------------------

    exports.encode_utf8 = encode_utf8;
    exports.encode_latin1 = encode_latin1;
    exports.decode_utf8 = decode_utf8;
    exports.decode_latin1 = decode_latin1;
    exports.to_hex = to_hex;

    exports.random_bytes = random_bytes;
    exports.crypto_scrypt = crypto_scrypt;

    return exports;
})();