sha224.js

'use strict';

/**
 * A JavaScript implementation of the Secure Hash Algorithm, SHA-256, as defined
 * in FIPS 180-2
 * Version 2.2-beta Copyright Angel Marin, Paul Johnston 2000 - 2009.
 * Other contributors: Greg Holt, Andrew Kepert, Ydnar, Lostinet
 *
 */

var inherits = require('inherits');
var Sha256 = require('./sha256');
var Hash = require('./hash');
var Buffer = require('safe-buffer').Buffer;

var W = new Array(64);

function Sha224() {
	this.init();

	this._w = W; // new Array(64)

	Hash.call(this, 64, 56);
}

inherits(Sha224, Sha256);

Sha224.prototype.init = function () {
	this._a = 0xc1059ed8;
	this._b = 0x367cd507;
	this._c = 0x3070dd17;
	this._d = 0xf70e5939;
	this._e = 0xffc00b31;
	this._f = 0x68581511;
	this._g = 0x64f98fa7;
	this._h = 0xbefa4fa4;

	return this;
};

Sha224.prototype._hash = function () {
	var H = Buffer.allocUnsafe(28);

	H.writeInt32BE(this._a, 0);
	H.writeInt32BE(this._b, 4);
	H.writeInt32BE(this._c, 8);
	H.writeInt32BE(this._d, 12);
	H.writeInt32BE(this._e, 16);
	H.writeInt32BE(this._f, 20);
	H.writeInt32BE(this._g, 24);

	return H;
};

module.exports = Sha224;