sha256.js

;(function (root, factory) {
	if (typeof exports === "object") {
		// CommonJS
		module.exports = exports = factory(require("./core"));
	}
	else if (typeof define === "function" && define.amd) {
		// AMD
		define(["./core"], factory);
	}
	else {
		// Global (browser)
		factory(root.CryptoJS);
	}
}(this, function (CryptoJS) {

	(function (Math) {
	    // Shortcuts
	    var C = CryptoJS;
	    var C_lib = C.lib;
	    var WordArray = C_lib.WordArray;
	    var Hasher = C_lib.Hasher;
	    var C_algo = C.algo;

	    // Initialization and round constants tables
	    var H = [];
	    var K = [];

	    // Compute constants
	    (function () {
	        function isPrime(n) {
	            var sqrtN = Math.sqrt(n);
	            for (var factor = 2; factor <= sqrtN; factor++) {
	                if (!(n % factor)) {
	                    return false;
	                }
	            }

	            return true;
	        }

	        function getFractionalBits(n) {
	            return ((n - (n | 0)) * 0x100000000) | 0;
	        }

	        var n = 2;
	        var nPrime = 0;
	        while (nPrime < 64) {
	            if (isPrime(n)) {
	                if (nPrime < 8) {
	                    H[nPrime] = getFractionalBits(Math.pow(n, 1 / 2));
	                }
	                K[nPrime] = getFractionalBits(Math.pow(n, 1 / 3));

	                nPrime++;
	            }

	            n++;
	        }
	    }());

	    // Reusable object
	    var W = [];

	    /**
	     * SHA-256 hash algorithm.
	     */
	    var SHA256 = C_algo.SHA256 = Hasher.extend({
	        _doReset: function () {
	            this._hash = new WordArray.init(H.slice(0));
	        },

	        _doProcessBlock: function (M, offset) {
	            // Shortcut
	            var H = this._hash.words;

	            // Working variables
	            var a = H[0];
	            var b = H[1];
	            var c = H[2];
	            var d = H[3];
	            var e = H[4];
	            var f = H[5];
	            var g = H[6];
	            var h = H[7];

	            // Computation
	            for (var i = 0; i < 64; i++) {
	                if (i < 16) {
	                    W[i] = M[offset + i] | 0;
	                } else {
	                    var gamma0x = W[i - 15];
	                    var gamma0  = ((gamma0x << 25) | (gamma0x >>> 7))  ^
	                                  ((gamma0x << 14) | (gamma0x >>> 18)) ^
	                                   (gamma0x >>> 3);

	                    var gamma1x = W[i - 2];
	                    var gamma1  = ((gamma1x << 15) | (gamma1x >>> 17)) ^
	                                  ((gamma1x << 13) | (gamma1x >>> 19)) ^
	                                   (gamma1x >>> 10);

	                    W[i] = gamma0 + W[i - 7] + gamma1 + W[i - 16];
	                }

	                var ch  = (e & f) ^ (~e & g);
	                var maj = (a & b) ^ (a & c) ^ (b & c);

	                var sigma0 = ((a << 30) | (a >>> 2)) ^ ((a << 19) | (a >>> 13)) ^ ((a << 10) | (a >>> 22));
	                var sigma1 = ((e << 26) | (e >>> 6)) ^ ((e << 21) | (e >>> 11)) ^ ((e << 7)  | (e >>> 25));

	                var t1 = h + sigma1 + ch + K[i] + W[i];
	                var t2 = sigma0 + maj;

	                h = g;
	                g = f;
	                f = e;
	                e = (d + t1) | 0;
	                d = c;
	                c = b;
	                b = a;
	                a = (t1 + t2) | 0;
	            }

	            // Intermediate hash value
	            H[0] = (H[0] + a) | 0;
	            H[1] = (H[1] + b) | 0;
	            H[2] = (H[2] + c) | 0;
	            H[3] = (H[3] + d) | 0;
	            H[4] = (H[4] + e) | 0;
	            H[5] = (H[5] + f) | 0;
	            H[6] = (H[6] + g) | 0;
	            H[7] = (H[7] + h) | 0;
	        },

	        _doFinalize: function () {
	            // Shortcuts
	            var data = this._data;
	            var dataWords = data.words;

	            var nBitsTotal = this._nDataBytes * 8;
	            var nBitsLeft = data.sigBytes * 8;

	            // Add padding
	            dataWords[nBitsLeft >>> 5] |= 0x80 << (24 - nBitsLeft % 32);
	            dataWords[(((nBitsLeft + 64) >>> 9) << 4) + 14] = Math.floor(nBitsTotal / 0x100000000);
	            dataWords[(((nBitsLeft + 64) >>> 9) << 4) + 15] = nBitsTotal;
	            data.sigBytes = dataWords.length * 4;

	            // Hash final blocks
	            this._process();

	            // Return final computed hash
	            return this._hash;
	        },

	        clone: function () {
	            var clone = Hasher.clone.call(this);
	            clone._hash = this._hash.clone();

	            return clone;
	        }
	    });

	    /**
	     * Shortcut function to the hasher's object interface.
	     *
	     * @param {WordArray|string} message The message to hash.
	     *
	     * @return {WordArray} The hash.
	     *
	     * @static
	     *
	     * @example
	     *
	     *     var hash = CryptoJS.SHA256('message');
	     *     var hash = CryptoJS.SHA256(wordArray);
	     */
	    C.SHA256 = Hasher._createHelper(SHA256);

	    /**
	     * Shortcut function to the HMAC's object interface.
	     *
	     * @param {WordArray|string} message The message to hash.
	     * @param {WordArray|string} key The secret key.
	     *
	     * @return {WordArray} The HMAC.
	     *
	     * @static
	     *
	     * @example
	     *
	     *     var hmac = CryptoJS.HmacSHA256(message, key);
	     */
	    C.HmacSHA256 = Hasher._createHmacHelper(SHA256);
	}(Math));


	return CryptoJS.SHA256;

}));