1 files changed, 44 insertions, 0 deletions
diff --git a/library/cryptojs/components/mode-ctr.js b/library/cryptojs/components/mode-ctr.js
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+++ b/library/cryptojs/components/mode-ctr.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
+*/
+/**
+ * Counter block mode.
+ */
+CryptoJS.mode.CTR = (function () {
+    var CTR = CryptoJS.lib.BlockCipherMode.extend();
+
+    var Encryptor = CTR.Encryptor = CTR.extend({
+        processBlock: function (words, offset) {
+            // Shortcuts
+            var cipher = this._cipher
+            var blockSize = cipher.blockSize;
+            var iv = this._iv;
+            var counter = this._counter;
+
+            // Generate keystream
+            if (iv) {
+                counter = this._counter = iv.slice(0);
+
+                // Remove IV for subsequent blocks
+                this._iv = undefined;
+            }
+            var keystream = counter.slice(0);
+            cipher.encryptBlock(keystream, 0);
+
+            // Increment counter
+            counter[blockSize - 1] = (counter[blockSize - 1] + 1) | 0
+
+            // Encrypt
+            for (var i = 0; i < blockSize; i++) {
+                words[offset + i] ^= keystream[i];
+            }
+        }
+    });
+
+    CTR.Decryptor = Encryptor;
+
+    return CTR;
+}());