node/node_modules/socket.io-client/lib/vendor/web-socket-js/flash-src/com/hurlant/crypto/symmetric/CFB8Mode.as

   1 /**
   2  * CFB8Mode
   3  *
   4  * An ActionScript 3 implementation of the CFB-8 confidentiality mode
   5  * Copyright (c) 2007 Henri Torgemane
   6  *
   7  * See LICENSE.txt for full license information.
   8  */
   9 package com.hurlant.crypto.symmetric
  10 {
  11         import com.hurlant.crypto.tests.TestCase;
  12         import flash.utils.ByteArray;
  13
  14         /**
  15          *
  16          * Note: The constructor accepts an optional padding argument, but ignores it otherwise.
  17          */
  18         public class CFB8Mode extends IVMode implements IMode
  19         {
  20                 public function CFB8Mode(key:ISymmetricKey, padding:IPad = null) {
  21                         super(key, null);
  22                 }
  23
  24                 public function encrypt(src:ByteArray):void {
  25                         var vector:ByteArray = getIV4e();
  26                         var tmp:ByteArray = new ByteArray;
  27                         for (var i:uint=0;i<src.length;i++) {
  28                                 tmp.position = 0;
  29                                 tmp.writeBytes(vector);
  30                                 key.encrypt(vector);
  31                                 src[i] ^= vector[0];
  32                                 // rotate
  33                                 for (var j:uint=0;j<blockSize-1;j++) {
  34                                         vector[j] = tmp[j+1];
  35                                 }
  36                                 vector[blockSize-1] = src[i];
  37                         }
  38                 }
  39
  40                 public function decrypt(src:ByteArray):void {
  41                         var vector:ByteArray = getIV4d();
  42                         var tmp:ByteArray = new ByteArray;
  43                         for (var i:uint=0;i<src.length;i++) {
  44                                 var c:uint = src[i];
  45                                 tmp.position = 0;
  46                                 tmp.writeBytes(vector); // I <- tmp
  47                                 key.encrypt(vector);    // O <- vector
  48                                 src[i] ^= vector[0];
  49                                 // rotate
  50                                 for (var j:uint=0;j<blockSize-1;j++) {
  51                                         vector[j] = tmp[j+1];
  52                                 }
  53                                 vector[blockSize-1] = c;
  54                         }
  55
  56                 }
  57                 public function toString():String {
  58                         return key.toString()+"-cfb8";
  59                 }
  60         }
  61 }