;(function (root, factory, undef) {
    if (typeof exports === "object") {
        // CommonJS
        module.exports = exports = factory(require("./core"), require("./enc-base64"), require("./md5"), require("./evpkdf"), require("./cipher-core"));
    } else if (typeof define === "function" && define.amd) {
        // AMD
        define(["./core", "./enc-base64", "./md5", "./evpkdf", "./cipher-core"], factory);
    } else {
        // Global (browser)
        factory(root.CryptoJS);
    }
}(this, function (CryptoJS) {

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

        /**
         * RC4 stream cipher algorithm.
         */
        var RC4 = C_algo.RC4 = StreamCipher.extend({
            _doReset: function () {
                // Shortcuts
                var key = this._key;
                var keyWords = key.words;
                var keySigBytes = key.sigBytes;

                // Init sbox
                var S = this._S = [];
                for (var i = 0; i < 256; i++) {
                    S[i] = i;
                }

                // Key setup
                for (var i = 0, j = 0; i < 256; i++) {
                    var keyByteIndex = i % keySigBytes;
                    var keyByte = (keyWords[keyByteIndex >>> 2] >>> (24 - (keyByteIndex % 4) * 8)) & 0xff;

                    j = (j + S[i] + keyByte) % 256;

                    // Swap
                    var t = S[i];
                    S[i] = S[j];
                    S[j] = t;
                }

                // Counters
                this._i = this._j = 0;
            },

            _doProcessBlock: function (M, offset) {
                M[offset] ^= generateKeystreamWord.call(this);
            },

            keySize: 256 / 32,

            ivSize: 0
        });

        function generateKeystreamWord() {
            // Shortcuts
            var S = this._S;
            var i = this._i;
            var j = this._j;

            // Generate keystream word
            var keystreamWord = 0;
            for (var n = 0; n < 4; n++) {
                i = (i + 1) % 256;
                j = (j + S[i]) % 256;

                // Swap
                var t = S[i];
                S[i] = S[j];
                S[j] = t;

                keystreamWord |= S[(S[i] + S[j]) % 256] << (24 - n * 8);
            }

            // Update counters
            this._i = i;
            this._j = j;

            return keystreamWord;
        }

        /**
         * Shortcut functions to the cipher's object interface.
         *
         * @example
         *
         *     var ciphertext = CryptoJS.RC4.encrypt(message, key, cfg);
         *     var plaintext  = CryptoJS.RC4.decrypt(ciphertext, key, cfg);
         */
        C.RC4 = StreamCipher._createHelper(RC4);

        /**
         * Modified RC4 stream cipher algorithm.
         */
        var RC4Drop = C_algo.RC4Drop = RC4.extend({
            /**
             * Configuration options.
             *
             * @property {number} drop The number of keystream words to drop. Default 192
             */
            cfg: RC4.cfg.extend({
                drop: 192
            }),

            _doReset: function () {
                RC4._doReset.call(this);

                // Drop
                for (var i = this.cfg.drop; i > 0; i--) {
                    generateKeystreamWord.call(this);
                }
            }
        });

        /**
         * Shortcut functions to the cipher's object interface.
         *
         * @example
         *
         *     var ciphertext = CryptoJS.RC4Drop.encrypt(message, key, cfg);
         *     var plaintext  = CryptoJS.RC4Drop.decrypt(ciphertext, key, cfg);
         */
        C.RC4Drop = StreamCipher._createHelper(RC4Drop);
    }());


    return CryptoJS.RC4;

}));