aes.js
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(function () {
// Shortcuts
var C = CryptoJS;
var C_lib = C.lib;
var BlockCipher = C_lib.BlockCipher;
var C_algo = C.algo;
// Lookup tables
var SBOX = [];
var INV_SBOX = [];
var SUB_MIX_0 = [];
var SUB_MIX_1 = [];
var SUB_MIX_2 = [];
var SUB_MIX_3 = [];
var INV_SUB_MIX_0 = [];
var INV_SUB_MIX_1 = [];
var INV_SUB_MIX_2 = [];
var INV_SUB_MIX_3 = [];
// Compute lookup tables
(function () {
// Compute double table
var d = [];
for (var i = 0; i < 256; i++) {
if (i < 128) {
d[i] = i << 1;
} else {
d[i] = (i << 1) ^ 0x11b;
}
}
// Walk GF(2^8)
var x = 0;
var xi = 0;
for (var i = 0; i < 256; i++) {
// Compute sbox
var sx = xi ^ (xi << 1) ^ (xi << 2) ^ (xi << 3) ^ (xi << 4);
sx = (sx >>> 8) ^ (sx & 0xff) ^ 0x63;
SBOX[x] = sx;
INV_SBOX[sx] = x;
// Compute multiplication
var x2 = d[x];
var x4 = d[x2];
var x8 = d[x4];
// Compute sub bytes, mix columns tables
var t = (d[sx] * 0x101) ^ (sx * 0x1010100);
SUB_MIX_0[x] = (t << 24) | (t >>> 8);
SUB_MIX_1[x] = (t << 16) | (t >>> 16);
SUB_MIX_2[x] = (t << 8) | (t >>> 24);
SUB_MIX_3[x] = t;
// Compute inv sub bytes, inv mix columns tables
var t = (x8 * 0x1010101) ^ (x4 * 0x10001) ^ (x2 * 0x101) ^ (x * 0x1010100);
INV_SUB_MIX_0[sx] = (t << 24) | (t >>> 8);
INV_SUB_MIX_1[sx] = (t << 16) | (t >>> 16);
INV_SUB_MIX_2[sx] = (t << 8) | (t >>> 24);
INV_SUB_MIX_3[sx] = t;
// Compute next counter
if (!x) {
x = xi = 1;
} else {
x = x2 ^ d[d[d[x8 ^ x2]]];
xi ^= d[d[xi]];
}
}
}());
// Precomputed Rcon lookup
var RCON = [0x00, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36];
/**
* AES block cipher algorithm.
*/
var AES = C_algo.AES = BlockCipher.extend({
_doReset: function () {
var t;
// Skip reset of nRounds has been set before and key did not change
if (this._nRounds && this._keyPriorReset === this._key) {
return;
}
// Shortcuts
var key = this._keyPriorReset = this._key;
var keyWords = key.words;
var keySize = key.sigBytes / 4;
// Compute number of rounds
var nRounds = this._nRounds = keySize + 6;
// Compute number of key schedule rows
var ksRows = (nRounds + 1) * 4;
// Compute key schedule
var keySchedule = this._keySchedule = [];
for (var ksRow = 0; ksRow < ksRows; ksRow++) {
if (ksRow < keySize) {
keySchedule[ksRow] = keyWords[ksRow];
} else {
t = keySchedule[ksRow - 1];
if (!(ksRow % keySize)) {
// Rot word
t = (t << 8) | (t >>> 24);
// Sub word
t = (SBOX[t >>> 24] << 24) | (SBOX[(t >>> 16) & 0xff] << 16) | (SBOX[(t >>> 8) & 0xff] << 8) | SBOX[t & 0xff];
// Mix Rcon
t ^= RCON[(ksRow / keySize) | 0] << 24;
} else if (keySize > 6 && ksRow % keySize == 4) {
// Sub word
t = (SBOX[t >>> 24] << 24) | (SBOX[(t >>> 16) & 0xff] << 16) | (SBOX[(t >>> 8) & 0xff] << 8) | SBOX[t & 0xff];
}
keySchedule[ksRow] = keySchedule[ksRow - keySize] ^ t;
}
}
// Compute inv key schedule
var invKeySchedule = this._invKeySchedule = [];
for (var invKsRow = 0; invKsRow < ksRows; invKsRow++) {
var ksRow = ksRows - invKsRow;
if (invKsRow % 4) {
var t = keySchedule[ksRow];
} else {
var t = keySchedule[ksRow - 4];
}
if (invKsRow < 4 || ksRow <= 4) {
invKeySchedule[invKsRow] = t;
} else {
invKeySchedule[invKsRow] = INV_SUB_MIX_0[SBOX[t >>> 24]] ^ INV_SUB_MIX_1[SBOX[(t >>> 16) & 0xff]] ^
INV_SUB_MIX_2[SBOX[(t >>> 8) & 0xff]] ^ INV_SUB_MIX_3[SBOX[t & 0xff]];
}
}
},
encryptBlock: function (M, offset) {
this._doCryptBlock(M, offset, this._keySchedule, SUB_MIX_0, SUB_MIX_1, SUB_MIX_2, SUB_MIX_3, SBOX);
},
decryptBlock: function (M, offset) {
// Swap 2nd and 4th rows
var t = M[offset + 1];
M[offset + 1] = M[offset + 3];
M[offset + 3] = t;
this._doCryptBlock(M, offset, this._invKeySchedule, INV_SUB_MIX_0, INV_SUB_MIX_1, INV_SUB_MIX_2, INV_SUB_MIX_3, INV_SBOX);
// Inv swap 2nd and 4th rows
var t = M[offset + 1];
M[offset + 1] = M[offset + 3];
M[offset + 3] = t;
},
_doCryptBlock: function (M, offset, keySchedule, SUB_MIX_0, SUB_MIX_1, SUB_MIX_2, SUB_MIX_3, SBOX) {
// Shortcut
var nRounds = this._nRounds;
// Get input, add round key
var s0 = M[offset] ^ keySchedule[0];
var s1 = M[offset + 1] ^ keySchedule[1];
var s2 = M[offset + 2] ^ keySchedule[2];
var s3 = M[offset + 3] ^ keySchedule[3];
// Key schedule row counter
var ksRow = 4;
// Rounds
for (var round = 1; round < nRounds; round++) {
// Shift rows, sub bytes, mix columns, add round key
var t0 = SUB_MIX_0[s0 >>> 24] ^ SUB_MIX_1[(s1 >>> 16) & 0xff] ^ SUB_MIX_2[(s2 >>> 8) & 0xff] ^ SUB_MIX_3[s3 & 0xff] ^ keySchedule[ksRow++];
var t1 = SUB_MIX_0[s1 >>> 24] ^ SUB_MIX_1[(s2 >>> 16) & 0xff] ^ SUB_MIX_2[(s3 >>> 8) & 0xff] ^ SUB_MIX_3[s0 & 0xff] ^ keySchedule[ksRow++];
var t2 = SUB_MIX_0[s2 >>> 24] ^ SUB_MIX_1[(s3 >>> 16) & 0xff] ^ SUB_MIX_2[(s0 >>> 8) & 0xff] ^ SUB_MIX_3[s1 & 0xff] ^ keySchedule[ksRow++];
var t3 = SUB_MIX_0[s3 >>> 24] ^ SUB_MIX_1[(s0 >>> 16) & 0xff] ^ SUB_MIX_2[(s1 >>> 8) & 0xff] ^ SUB_MIX_3[s2 & 0xff] ^ keySchedule[ksRow++];
// Update state
s0 = t0;
s1 = t1;
s2 = t2;
s3 = t3;
}
// Shift rows, sub bytes, add round key
var t0 = ((SBOX[s0 >>> 24] << 24) | (SBOX[(s1 >>> 16) & 0xff] << 16) | (SBOX[(s2 >>> 8) & 0xff] << 8) | SBOX[s3 & 0xff]) ^ keySchedule[ksRow++];
var t1 = ((SBOX[s1 >>> 24] << 24) | (SBOX[(s2 >>> 16) & 0xff] << 16) | (SBOX[(s3 >>> 8) & 0xff] << 8) | SBOX[s0 & 0xff]) ^ keySchedule[ksRow++];
var t2 = ((SBOX[s2 >>> 24] << 24) | (SBOX[(s3 >>> 16) & 0xff] << 16) | (SBOX[(s0 >>> 8) & 0xff] << 8) | SBOX[s1 & 0xff]) ^ keySchedule[ksRow++];
var t3 = ((SBOX[s3 >>> 24] << 24) | (SBOX[(s0 >>> 16) & 0xff] << 16) | (SBOX[(s1 >>> 8) & 0xff] << 8) | SBOX[s2 & 0xff]) ^ keySchedule[ksRow++];
// Set output
M[offset] = t0;
M[offset + 1] = t1;
M[offset + 2] = t2;
M[offset + 3] = t3;
},
keySize: 256/32
});
/**
* Shortcut functions to the cipher's object interface.
*
* @example
*
* var ciphertext = CryptoJS.AES.encrypt(message, key, cfg);
* var plaintext = CryptoJS.AES.decrypt(ciphertext, key, cfg);
*/
C.AES = BlockCipher._createHelper(AES);
}());