/*!
|
* Crypto-JS v1.1.0
|
* http://code.google.com/p/crypto-js/
|
* Copyright (c) 2009, Jeff Mott. All rights reserved.
|
* http://code.google.com/p/crypto-js/wiki/License
|
*/
|
Crypto.mode.CBC = {
|
|
encrypt: function (cipher, m, iv) {
|
|
var blockSizeInBytes = cipher._blocksize * 4;
|
|
// Pad
|
m.push(0x80);
|
|
// Encrypt each block
|
for (var offset = 0; offset < m.length; offset += blockSizeInBytes) {
|
|
if (offset == 0) {
|
// XOR first block using IV
|
for (var i = 0; i < blockSizeInBytes; i++)
|
m[i] ^= iv[i];
|
}
|
else {
|
// XOR this block using previous crypted block
|
for (var i = 0; i < blockSizeInBytes; i++)
|
m[offset + i] ^= m[offset + i - blockSizeInBytes];
|
}
|
|
// Encrypt block
|
cipher._encryptblock(m, offset);
|
|
}
|
|
},
|
|
decrypt: function (cipher, c, iv) {
|
|
var blockSizeInBytes = cipher._blocksize * 4;
|
|
// Decrypt each block
|
for (var offset = 0; offset < c.length; offset += blockSizeInBytes) {
|
|
// Save this crypted block
|
var thisCryptedBlock = c.slice(offset, offset + blockSizeInBytes);
|
|
// Decrypt block
|
cipher._decryptblock(c, offset);
|
|
if (offset == 0) {
|
// XOR first block using IV
|
for (var i = 0; i < blockSizeInBytes; i++)
|
c[i] ^= iv[i];
|
}
|
else {
|
// XOR decrypted block using previous crypted block
|
for (var i = 0; i < blockSizeInBytes; i++)
|
c[offset + i] ^= prevCryptedBlock[i];
|
}
|
|
// This crypted block is the new previous crypted block
|
var prevCryptedBlock = thisCryptedBlock;
|
|
}
|
|
// Strip padding
|
while (c.pop() != 0x80) ;
|
|
}
|
|
};
|
