103 lines
2 KiB
JavaScript
103 lines
2 KiB
JavaScript
|
/*
|
||
|
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
|
||
|
*/
|
||
|
/** @preserve
|
||
|
* Counter block mode compatible with Dr Brian Gladman fileenc.c
|
||
|
* derived from CryptoJS.mode.CTR
|
||
|
* Jan Hruby jhruby.web@gmail.com
|
||
|
*/
|
||
|
CryptoJS.mode.CTRGladman = (function () {
|
||
|
var CTRGladman = CryptoJS.lib.BlockCipherMode.extend();
|
||
|
|
||
|
function incWord(word)
|
||
|
{
|
||
|
if (((word >> 24) & 0xff) === 0xff) { //overflow
|
||
|
var b1 = (word >> 16)&0xff;
|
||
|
var b2 = (word >> 8)&0xff;
|
||
|
var b3 = word & 0xff;
|
||
|
|
||
|
if (b1 === 0xff) // overflow b1
|
||
|
{
|
||
|
b1 = 0;
|
||
|
if (b2 === 0xff)
|
||
|
{
|
||
|
b2 = 0;
|
||
|
if (b3 === 0xff)
|
||
|
{
|
||
|
b3 = 0;
|
||
|
}
|
||
|
else
|
||
|
{
|
||
|
++b3;
|
||
|
}
|
||
|
}
|
||
|
else
|
||
|
{
|
||
|
++b2;
|
||
|
}
|
||
|
}
|
||
|
else
|
||
|
{
|
||
|
++b1;
|
||
|
}
|
||
|
|
||
|
word = 0;
|
||
|
word += (b1 << 16);
|
||
|
word += (b2 << 8);
|
||
|
word += b3;
|
||
|
}
|
||
|
else
|
||
|
{
|
||
|
word += (0x01 << 24);
|
||
|
}
|
||
|
return word;
|
||
|
}
|
||
|
|
||
|
function incCounter(counter)
|
||
|
{
|
||
|
if ((counter[0] = incWord(counter[0])) === 0)
|
||
|
{
|
||
|
// encr_data in fileenc.c from Dr Brian Gladman's counts only with DWORD j < 8
|
||
|
counter[1] = incWord(counter[1]);
|
||
|
}
|
||
|
return counter;
|
||
|
}
|
||
|
|
||
|
var Encryptor = CTRGladman.Encryptor = CTRGladman.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;
|
||
|
}
|
||
|
|
||
|
incCounter(counter);
|
||
|
|
||
|
var keystream = counter.slice(0);
|
||
|
cipher.encryptBlock(keystream, 0);
|
||
|
|
||
|
// Encrypt
|
||
|
for (var i = 0; i < blockSize; i++) {
|
||
|
words[offset + i] ^= keystream[i];
|
||
|
}
|
||
|
}
|
||
|
});
|
||
|
|
||
|
CTRGladman.Decryptor = Encryptor;
|
||
|
|
||
|
return CTRGladman;
|
||
|
}());
|
||
|
|
||
|
|