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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;
// Reusable objects
var S = [];
var C_ = [];
var G = [];
/**
* Rabbit stream cipher algorithm
*/
var Rabbit = C_algo.Rabbit = StreamCipher.extend({
_doReset: function () {
// Shortcuts
var K = this._key.words;
var iv = this.cfg.iv;
// Swap endian
for (var i = 0; i < 4; i++) {
K[i] = (((K[i] << 8) | (K[i] >>> 24)) & 0x00ff00ff) |
(((K[i] << 24) | (K[i] >>> 8)) & 0xff00ff00);
}
// Generate initial state values
var X = this._X = [
K[0], (K[3] << 16) | (K[2] >>> 16),
K[1], (K[0] << 16) | (K[3] >>> 16),
K[2], (K[1] << 16) | (K[0] >>> 16),
K[3], (K[2] << 16) | (K[1] >>> 16)
];
// Generate initial counter values
var C = this._C = [
(K[2] << 16) | (K[2] >>> 16), (K[0] & 0xffff0000) | (K[1] & 0x0000ffff),
(K[3] << 16) | (K[3] >>> 16), (K[1] & 0xffff0000) | (K[2] & 0x0000ffff),
(K[0] << 16) | (K[0] >>> 16), (K[2] & 0xffff0000) | (K[3] & 0x0000ffff),
(K[1] << 16) | (K[1] >>> 16), (K[3] & 0xffff0000) | (K[0] & 0x0000ffff)
];
// Carry bit
this._b = 0;
// Iterate the system four times
for (var i = 0; i < 4; i++) {
nextState.call(this);
}
// Modify the counters
for (var i = 0; i < 8; i++) {
C[i] ^= X[(i + 4) & 7];
}
// IV setup
if (iv) {
// Shortcuts
var IV = iv.words;
var IV_0 = IV[0];
var IV_1 = IV[1];
// Generate four subvectors
var i0 = (((IV_0 << 8) | (IV_0 >>> 24)) & 0x00ff00ff) | (((IV_0 << 24) | (IV_0 >>> 8)) & 0xff00ff00);
var i2 = (((IV_1 << 8) | (IV_1 >>> 24)) & 0x00ff00ff) | (((IV_1 << 24) | (IV_1 >>> 8)) & 0xff00ff00);
var i1 = (i0 >>> 16) | (i2 & 0xffff0000);
var i3 = (i2 << 16) | (i0 & 0x0000ffff);
// Modify counter values
C[0] ^= i0;
C[1] ^= i1;
C[2] ^= i2;
C[3] ^= i3;
C[4] ^= i0;
C[5] ^= i1;
C[6] ^= i2;
C[7] ^= i3;
// Iterate the system four times
for (var i = 0; i < 4; i++) {
nextState.call(this);
}
}
},
_doProcessBlock: function (M, offset) {
// Shortcut
var X = this._X;
// Iterate the system
nextState.call(this);
// Generate four keystream words
S[0] = X[0] ^ (X[5] >>> 16) ^ (X[3] << 16);
S[1] = X[2] ^ (X[7] >>> 16) ^ (X[5] << 16);
S[2] = X[4] ^ (X[1] >>> 16) ^ (X[7] << 16);
S[3] = X[6] ^ (X[3] >>> 16) ^ (X[1] << 16);
for (var i = 0; i < 4; i++) {
// Swap endian
S[i] = (((S[i] << 8) | (S[i] >>> 24)) & 0x00ff00ff) |
(((S[i] << 24) | (S[i] >>> 8)) & 0xff00ff00);
// Encrypt
M[offset + i] ^= S[i];
}
},
blockSize: 128/32,
ivSize: 64/32
});
function nextState() {
// Shortcuts
var X = this._X;
var C = this._C;
// Save old counter values
for (var i = 0; i < 8; i++) {
C_[i] = C[i];
}
// Calculate new counter values
C[0] = (C[0] + 0x4d34d34d + this._b) | 0;
C[1] = (C[1] + 0xd34d34d3 + ((C[0] >>> 0) < (C_[0] >>> 0) ? 1 : 0)) | 0;
C[2] = (C[2] + 0x34d34d34 + ((C[1] >>> 0) < (C_[1] >>> 0) ? 1 : 0)) | 0;
C[3] = (C[3] + 0x4d34d34d + ((C[2] >>> 0) < (C_[2] >>> 0) ? 1 : 0)) | 0;
C[4] = (C[4] + 0xd34d34d3 + ((C[3] >>> 0) < (C_[3] >>> 0) ? 1 : 0)) | 0;
C[5] = (C[5] + 0x34d34d34 + ((C[4] >>> 0) < (C_[4] >>> 0) ? 1 : 0)) | 0;
C[6] = (C[6] + 0x4d34d34d + ((C[5] >>> 0) < (C_[5] >>> 0) ? 1 : 0)) | 0;
C[7] = (C[7] + 0xd34d34d3 + ((C[6] >>> 0) < (C_[6] >>> 0) ? 1 : 0)) | 0;
this._b = (C[7] >>> 0) < (C_[7] >>> 0) ? 1 : 0;
// Calculate the g-values
for (var i = 0; i < 8; i++) {
var gx = X[i] + C[i];
// Construct high and low argument for squaring
var ga = gx & 0xffff;
var gb = gx >>> 16;
// Calculate high and low result of squaring
var gh = ((((ga * ga) >>> 17) + ga * gb) >>> 15) + gb * gb;
var gl = (((gx & 0xffff0000) * gx) | 0) + (((gx & 0x0000ffff) * gx) | 0);
// High XOR low
G[i] = gh ^ gl;
}
// Calculate new state values
X[0] = (G[0] + ((G[7] << 16) | (G[7] >>> 16)) + ((G[6] << 16) | (G[6] >>> 16))) | 0;
X[1] = (G[1] + ((G[0] << 8) | (G[0] >>> 24)) + G[7]) | 0;
X[2] = (G[2] + ((G[1] << 16) | (G[1] >>> 16)) + ((G[0] << 16) | (G[0] >>> 16))) | 0;
X[3] = (G[3] + ((G[2] << 8) | (G[2] >>> 24)) + G[1]) | 0;
X[4] = (G[4] + ((G[3] << 16) | (G[3] >>> 16)) + ((G[2] << 16) | (G[2] >>> 16))) | 0;
X[5] = (G[5] + ((G[4] << 8) | (G[4] >>> 24)) + G[3]) | 0;
X[6] = (G[6] + ((G[5] << 16) | (G[5] >>> 16)) + ((G[4] << 16) | (G[4] >>> 16))) | 0;
X[7] = (G[7] + ((G[6] << 8) | (G[6] >>> 24)) + G[5]) | 0;
}
/**
* Shortcut functions to the cipher's object interface.
*
* @example
*
* var ciphertext = CryptoJS.Rabbit.encrypt(message, key, cfg);
* var plaintext = CryptoJS.Rabbit.decrypt(ciphertext, key, cfg);
*/
C.Rabbit = StreamCipher._createHelper(Rabbit);
}());
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