1 files changed, 125 insertions, 0 deletions
diff --git a/library/cryptojs/components/rc4.js b/library/cryptojs/components/rc4.js
new file mode 100644
index 000000000..69ccb1375
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+++ b/library/cryptojs/components/rc4.js
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+/*
+CryptoJS v3.1.2
+code.google.com/p/crypto-js
+(c) 2009-2013 by Jeff Mott. All rights reserved.
+code.google.com/p/crypto-js/wiki/License
+*/
+(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);
+}());