(function(){ | |
// Shortcuts | |
var C = Crypto, | |
util = C.util, | |
charenc = C.charenc, | |
UTF8 = charenc.UTF8; | |
// Precomputed SBOX | |
var SBOX = [ 0x63, 0x7c, 0x77, 0x7b, 0xf2, 0x6b, 0x6f, 0xc5, | |
0x30, 0x01, 0x67, 0x2b, 0xfe, 0xd7, 0xab, 0x76, | |
0xca, 0x82, 0xc9, 0x7d, 0xfa, 0x59, 0x47, 0xf0, | |
0xad, 0xd4, 0xa2, 0xaf, 0x9c, 0xa4, 0x72, 0xc0, | |
0xb7, 0xfd, 0x93, 0x26, 0x36, 0x3f, 0xf7, 0xcc, | |
0x34, 0xa5, 0xe5, 0xf1, 0x71, 0xd8, 0x31, 0x15, | |
0x04, 0xc7, 0x23, 0xc3, 0x18, 0x96, 0x05, 0x9a, | |
0x07, 0x12, 0x80, 0xe2, 0xeb, 0x27, 0xb2, 0x75, | |
0x09, 0x83, 0x2c, 0x1a, 0x1b, 0x6e, 0x5a, 0xa0, | |
0x52, 0x3b, 0xd6, 0xb3, 0x29, 0xe3, 0x2f, 0x84, | |
0x53, 0xd1, 0x00, 0xed, 0x20, 0xfc, 0xb1, 0x5b, | |
0x6a, 0xcb, 0xbe, 0x39, 0x4a, 0x4c, 0x58, 0xcf, | |
0xd0, 0xef, 0xaa, 0xfb, 0x43, 0x4d, 0x33, 0x85, | |
0x45, 0xf9, 0x02, 0x7f, 0x50, 0x3c, 0x9f, 0xa8, | |
0x51, 0xa3, 0x40, 0x8f, 0x92, 0x9d, 0x38, 0xf5, | |
0xbc, 0xb6, 0xda, 0x21, 0x10, 0xff, 0xf3, 0xd2, | |
0xcd, 0x0c, 0x13, 0xec, 0x5f, 0x97, 0x44, 0x17, | |
0xc4, 0xa7, 0x7e, 0x3d, 0x64, 0x5d, 0x19, 0x73, | |
0x60, 0x81, 0x4f, 0xdc, 0x22, 0x2a, 0x90, 0x88, | |
0x46, 0xee, 0xb8, 0x14, 0xde, 0x5e, 0x0b, 0xdb, | |
0xe0, 0x32, 0x3a, 0x0a, 0x49, 0x06, 0x24, 0x5c, | |
0xc2, 0xd3, 0xac, 0x62, 0x91, 0x95, 0xe4, 0x79, | |
0xe7, 0xc8, 0x37, 0x6d, 0x8d, 0xd5, 0x4e, 0xa9, | |
0x6c, 0x56, 0xf4, 0xea, 0x65, 0x7a, 0xae, 0x08, | |
0xba, 0x78, 0x25, 0x2e, 0x1c, 0xa6, 0xb4, 0xc6, | |
0xe8, 0xdd, 0x74, 0x1f, 0x4b, 0xbd, 0x8b, 0x8a, | |
0x70, 0x3e, 0xb5, 0x66, 0x48, 0x03, 0xf6, 0x0e, | |
0x61, 0x35, 0x57, 0xb9, 0x86, 0xc1, 0x1d, 0x9e, | |
0xe1, 0xf8, 0x98, 0x11, 0x69, 0xd9, 0x8e, 0x94, | |
0x9b, 0x1e, 0x87, 0xe9, 0xce, 0x55, 0x28, 0xdf, | |
0x8c, 0xa1, 0x89, 0x0d, 0xbf, 0xe6, 0x42, 0x68, | |
0x41, 0x99, 0x2d, 0x0f, 0xb0, 0x54, 0xbb, 0x16 ]; | |
// Compute inverse SBOX lookup table | |
for (var INVSBOX = [], i = 0; i < 256; i++) INVSBOX[SBOX[i]] = i; | |
// Compute mulitplication in GF(2^8) lookup tables | |
var MULT2 = [], | |
MULT3 = [], | |
MULT9 = [], | |
MULTB = [], | |
MULTD = [], | |
MULTE = []; | |
function xtime(a, b) { | |
for (var result = 0, i = 0; i < 8; i++) { | |
if (b & 1) result ^= a; | |
var hiBitSet = a & 0x80; | |
a = (a << 1) & 0xFF; | |
if (hiBitSet) a ^= 0x1b; | |
b >>>= 1; | |
} | |
return result; | |
} | |
for (var i = 0; i < 256; i++) { | |
MULT2[i] = xtime(i,2); | |
MULT3[i] = xtime(i,3); | |
MULT9[i] = xtime(i,9); | |
MULTB[i] = xtime(i,0xB); | |
MULTD[i] = xtime(i,0xD); | |
MULTE[i] = xtime(i,0xE); | |
} | |
// Precomputed RCon lookup | |
var RCON = [0x00, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36]; | |
// Inner state | |
var state = [[], [], [], []], | |
keylength, | |
nrounds, | |
keyschedule; | |
var AES = C.AES = { | |
/** | |
* Public API | |
*/ | |
encrypt: function (message, password, options) { | |
options = options || {}; | |
// Determine mode | |
var mode = options.mode || new C.mode.OFB; | |
// Allow mode to override options | |
if (mode.fixOptions) mode.fixOptions(options); | |
var | |
// Convert to bytes if message is a string | |
m = ( | |
message.constructor == String ? | |
UTF8.stringToBytes(message) : | |
message | |
), | |
// Generate random IV | |
iv = options.iv || util.randomBytes(AES._blocksize * 4), | |
// Generate key | |
k = ( | |
password.constructor == String ? | |
// Derive key from passphrase | |
C.PBKDF2(password, iv, 32, { asBytes: true }) : | |
// else, assume byte array representing cryptographic key | |
password | |
); | |
// Encrypt | |
AES._init(k); | |
mode.encrypt(AES, m, iv); | |
// Return ciphertext | |
m = options.iv ? m : iv.concat(m); | |
return (options && options.asBytes) ? m : util.bytesToBase64(m); | |
}, | |
decrypt: function (ciphertext, password, options) { | |
options = options || {}; | |
// Determine mode | |
var mode = options.mode || new C.mode.OFB; | |
// Allow mode to override options | |
if (mode.fixOptions) mode.fixOptions(options); | |
var | |
// Convert to bytes if ciphertext is a string | |
c = ( | |
ciphertext.constructor == String ? | |
util.base64ToBytes(ciphertext): | |
ciphertext | |
), | |
// Separate IV and message | |
iv = options.iv || c.splice(0, AES._blocksize * 4), | |
// Generate key | |
k = ( | |
password.constructor == String ? | |
// Derive key from passphrase | |
C.PBKDF2(password, iv, 32, { asBytes: true }) : | |
// else, assume byte array representing cryptographic key | |
password | |
); | |
// Decrypt | |
AES._init(k); | |
mode.decrypt(AES, c, iv); | |
// Return plaintext | |
return (options && options.asBytes) ? c : UTF8.bytesToString(c); | |
}, | |
/** | |
* Package private methods and properties | |
*/ | |
_blocksize: 4, | |
_encryptblock: function (m, offset) { | |
// Set input | |
for (var row = 0; row < AES._blocksize; row++) { | |
for (var col = 0; col < 4; col++) | |
state[row][col] = m[offset + col * 4 + row]; | |
} | |
// Add round key | |
for (var row = 0; row < 4; row++) { | |
for (var col = 0; col < 4; col++) | |
state[row][col] ^= keyschedule[col][row]; | |
} | |
for (var round = 1; round < nrounds; round++) { | |
// Sub bytes | |
for (var row = 0; row < 4; row++) { | |
for (var col = 0; col < 4; col++) | |
state[row][col] = SBOX[state[row][col]]; | |
} | |
// Shift rows | |
state[1].push(state[1].shift()); | |
state[2].push(state[2].shift()); | |
state[2].push(state[2].shift()); | |
state[3].unshift(state[3].pop()); | |
// Mix columns | |
for (var col = 0; col < 4; col++) { | |
var s0 = state[0][col], | |
s1 = state[1][col], | |
s2 = state[2][col], | |
s3 = state[3][col]; | |
state[0][col] = MULT2[s0] ^ MULT3[s1] ^ s2 ^ s3; | |
state[1][col] = s0 ^ MULT2[s1] ^ MULT3[s2] ^ s3; | |
state[2][col] = s0 ^ s1 ^ MULT2[s2] ^ MULT3[s3]; | |
state[3][col] = MULT3[s0] ^ s1 ^ s2 ^ MULT2[s3]; | |
} | |
// Add round key | |
for (var row = 0; row < 4; row++) { | |
for (var col = 0; col < 4; col++) | |
state[row][col] ^= keyschedule[round * 4 + col][row]; | |
} | |
} | |
// Sub bytes | |
for (var row = 0; row < 4; row++) { | |
for (var col = 0; col < 4; col++) | |
state[row][col] = SBOX[state[row][col]]; | |
} | |
// Shift rows | |
state[1].push(state[1].shift()); | |
state[2].push(state[2].shift()); | |
state[2].push(state[2].shift()); | |
state[3].unshift(state[3].pop()); | |
// Add round key | |
for (var row = 0; row < 4; row++) { | |
for (var col = 0; col < 4; col++) | |
state[row][col] ^= keyschedule[nrounds * 4 + col][row]; | |
} | |
// Set output | |
for (var row = 0; row < AES._blocksize; row++) { | |
for (var col = 0; col < 4; col++) | |
m[offset + col * 4 + row] = state[row][col]; | |
} | |
}, | |
_decryptblock: function (c, offset) { | |
// Set input | |
for (var row = 0; row < AES._blocksize; row++) { | |
for (var col = 0; col < 4; col++) | |
state[row][col] = c[offset + col * 4 + row]; | |
} | |
// Add round key | |
for (var row = 0; row < 4; row++) { | |
for (var col = 0; col < 4; col++) | |
state[row][col] ^= keyschedule[nrounds * 4 + col][row]; | |
} | |
for (var round = 1; round < nrounds; round++) { | |
// Inv shift rows | |
state[1].unshift(state[1].pop()); | |
state[2].push(state[2].shift()); | |
state[2].push(state[2].shift()); | |
state[3].push(state[3].shift()); | |
// Inv sub bytes | |
for (var row = 0; row < 4; row++) { | |
for (var col = 0; col < 4; col++) | |
state[row][col] = INVSBOX[state[row][col]]; | |
} | |
// Add round key | |
for (var row = 0; row < 4; row++) { | |
for (var col = 0; col < 4; col++) | |
state[row][col] ^= keyschedule[(nrounds - round) * 4 + col][row]; | |
} | |
// Inv mix columns | |
for (var col = 0; col < 4; col++) { | |
var s0 = state[0][col], | |
s1 = state[1][col], | |
s2 = state[2][col], | |
s3 = state[3][col]; | |
state[0][col] = MULTE[s0] ^ MULTB[s1] ^ MULTD[s2] ^ MULT9[s3]; | |
state[1][col] = MULT9[s0] ^ MULTE[s1] ^ MULTB[s2] ^ MULTD[s3]; | |
state[2][col] = MULTD[s0] ^ MULT9[s1] ^ MULTE[s2] ^ MULTB[s3]; | |
state[3][col] = MULTB[s0] ^ MULTD[s1] ^ MULT9[s2] ^ MULTE[s3]; | |
} | |
} | |
// Inv shift rows | |
state[1].unshift(state[1].pop()); | |
state[2].push(state[2].shift()); | |
state[2].push(state[2].shift()); | |
state[3].push(state[3].shift()); | |
// Inv sub bytes | |
for (var row = 0; row < 4; row++) { | |
for (var col = 0; col < 4; col++) | |
state[row][col] = INVSBOX[state[row][col]]; | |
} | |
// Add round key | |
for (var row = 0; row < 4; row++) { | |
for (var col = 0; col < 4; col++) | |
state[row][col] ^= keyschedule[col][row]; | |
} | |
// Set output | |
for (var row = 0; row < AES._blocksize; row++) { | |
for (var col = 0; col < 4; col++) | |
c[offset + col * 4 + row] = state[row][col]; | |
} | |
}, | |
/** | |
* Private methods | |
*/ | |
_init: function (k) { | |
keylength = k.length / 4; | |
nrounds = keylength + 6; | |
AES._keyexpansion(k); | |
}, | |
// Generate a key schedule | |
_keyexpansion: function (k) { | |
keyschedule = []; | |
for (var row = 0; row < keylength; row++) { | |
keyschedule[row] = [ | |
k[row * 4], | |
k[row * 4 + 1], | |
k[row * 4 + 2], | |
k[row * 4 + 3] | |
]; | |
} | |
for (var row = keylength; row < AES._blocksize * (nrounds + 1); row++) { | |
var temp = [ | |
keyschedule[row - 1][0], | |
keyschedule[row - 1][1], | |
keyschedule[row - 1][2], | |
keyschedule[row - 1][3] | |
]; | |
if (row % keylength == 0) { | |
// Rot word | |
temp.push(temp.shift()); | |
// Sub word | |
temp[0] = SBOX[temp[0]]; | |
temp[1] = SBOX[temp[1]]; | |
temp[2] = SBOX[temp[2]]; | |
temp[3] = SBOX[temp[3]]; | |
temp[0] ^= RCON[row / keylength]; | |
} else if (keylength > 6 && row % keylength == 4) { | |
// Sub word | |
temp[0] = SBOX[temp[0]]; | |
temp[1] = SBOX[temp[1]]; | |
temp[2] = SBOX[temp[2]]; | |
temp[3] = SBOX[temp[3]]; | |
} | |
keyschedule[row] = [ | |
keyschedule[row - keylength][0] ^ temp[0], | |
keyschedule[row - keylength][1] ^ temp[1], | |
keyschedule[row - keylength][2] ^ temp[2], | |
keyschedule[row - keylength][3] ^ temp[3] | |
]; | |
} | |
} | |
}; | |
})(); |