// based on the aes implimentation in triple sec
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// https://github.com/keybase/triplesec
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// which is in turn based on the one from crypto-js
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// https://code.google.com/p/crypto-js/
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var Buffer = require('safe-buffer').Buffer
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function asUInt32Array (buf) {
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if (!Buffer.isBuffer(buf)) buf = Buffer.from(buf)
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var len = (buf.length / 4) | 0
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var out = new Array(len)
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for (var i = 0; i < len; i++) {
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out[i] = buf.readUInt32BE(i * 4)
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}
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return out
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}
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function scrubVec (v) {
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for (var i = 0; i < v.length; v++) {
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v[i] = 0
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}
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}
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function cryptBlock (M, keySchedule, SUB_MIX, SBOX, nRounds) {
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var SUB_MIX0 = SUB_MIX[0]
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var SUB_MIX1 = SUB_MIX[1]
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var SUB_MIX2 = SUB_MIX[2]
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var SUB_MIX3 = SUB_MIX[3]
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var s0 = M[0] ^ keySchedule[0]
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var s1 = M[1] ^ keySchedule[1]
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var s2 = M[2] ^ keySchedule[2]
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var s3 = M[3] ^ keySchedule[3]
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var t0, t1, t2, t3
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var ksRow = 4
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for (var round = 1; round < nRounds; round++) {
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t0 = SUB_MIX0[s0 >>> 24] ^ SUB_MIX1[(s1 >>> 16) & 0xff] ^ SUB_MIX2[(s2 >>> 8) & 0xff] ^ SUB_MIX3[s3 & 0xff] ^ keySchedule[ksRow++]
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t1 = SUB_MIX0[s1 >>> 24] ^ SUB_MIX1[(s2 >>> 16) & 0xff] ^ SUB_MIX2[(s3 >>> 8) & 0xff] ^ SUB_MIX3[s0 & 0xff] ^ keySchedule[ksRow++]
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t2 = SUB_MIX0[s2 >>> 24] ^ SUB_MIX1[(s3 >>> 16) & 0xff] ^ SUB_MIX2[(s0 >>> 8) & 0xff] ^ SUB_MIX3[s1 & 0xff] ^ keySchedule[ksRow++]
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t3 = SUB_MIX0[s3 >>> 24] ^ SUB_MIX1[(s0 >>> 16) & 0xff] ^ SUB_MIX2[(s1 >>> 8) & 0xff] ^ SUB_MIX3[s2 & 0xff] ^ keySchedule[ksRow++]
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s0 = t0
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s1 = t1
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s2 = t2
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s3 = t3
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}
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t0 = ((SBOX[s0 >>> 24] << 24) | (SBOX[(s1 >>> 16) & 0xff] << 16) | (SBOX[(s2 >>> 8) & 0xff] << 8) | SBOX[s3 & 0xff]) ^ keySchedule[ksRow++]
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t1 = ((SBOX[s1 >>> 24] << 24) | (SBOX[(s2 >>> 16) & 0xff] << 16) | (SBOX[(s3 >>> 8) & 0xff] << 8) | SBOX[s0 & 0xff]) ^ keySchedule[ksRow++]
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t2 = ((SBOX[s2 >>> 24] << 24) | (SBOX[(s3 >>> 16) & 0xff] << 16) | (SBOX[(s0 >>> 8) & 0xff] << 8) | SBOX[s1 & 0xff]) ^ keySchedule[ksRow++]
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t3 = ((SBOX[s3 >>> 24] << 24) | (SBOX[(s0 >>> 16) & 0xff] << 16) | (SBOX[(s1 >>> 8) & 0xff] << 8) | SBOX[s2 & 0xff]) ^ keySchedule[ksRow++]
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t0 = t0 >>> 0
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t1 = t1 >>> 0
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t2 = t2 >>> 0
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t3 = t3 >>> 0
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return [t0, t1, t2, t3]
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}
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// AES constants
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var RCON = [0x00, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36]
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var G = (function () {
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// Compute double table
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var d = new Array(256)
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for (var j = 0; j < 256; j++) {
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if (j < 128) {
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d[j] = j << 1
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} else {
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d[j] = (j << 1) ^ 0x11b
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}
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}
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var SBOX = []
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var INV_SBOX = []
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var SUB_MIX = [[], [], [], []]
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var INV_SUB_MIX = [[], [], [], []]
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// Walk GF(2^8)
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var x = 0
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var xi = 0
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for (var i = 0; i < 256; ++i) {
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// Compute sbox
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var sx = xi ^ (xi << 1) ^ (xi << 2) ^ (xi << 3) ^ (xi << 4)
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sx = (sx >>> 8) ^ (sx & 0xff) ^ 0x63
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SBOX[x] = sx
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INV_SBOX[sx] = x
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// Compute multiplication
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var x2 = d[x]
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var x4 = d[x2]
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var x8 = d[x4]
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// Compute sub bytes, mix columns tables
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var t = (d[sx] * 0x101) ^ (sx * 0x1010100)
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SUB_MIX[0][x] = (t << 24) | (t >>> 8)
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SUB_MIX[1][x] = (t << 16) | (t >>> 16)
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SUB_MIX[2][x] = (t << 8) | (t >>> 24)
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SUB_MIX[3][x] = t
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// Compute inv sub bytes, inv mix columns tables
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t = (x8 * 0x1010101) ^ (x4 * 0x10001) ^ (x2 * 0x101) ^ (x * 0x1010100)
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INV_SUB_MIX[0][sx] = (t << 24) | (t >>> 8)
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INV_SUB_MIX[1][sx] = (t << 16) | (t >>> 16)
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INV_SUB_MIX[2][sx] = (t << 8) | (t >>> 24)
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INV_SUB_MIX[3][sx] = t
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if (x === 0) {
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x = xi = 1
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} else {
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x = x2 ^ d[d[d[x8 ^ x2]]]
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xi ^= d[d[xi]]
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}
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}
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return {
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SBOX: SBOX,
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INV_SBOX: INV_SBOX,
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SUB_MIX: SUB_MIX,
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INV_SUB_MIX: INV_SUB_MIX
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}
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})()
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function AES (key) {
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this._key = asUInt32Array(key)
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this._reset()
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}
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AES.blockSize = 4 * 4
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AES.keySize = 256 / 8
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AES.prototype.blockSize = AES.blockSize
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AES.prototype.keySize = AES.keySize
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AES.prototype._reset = function () {
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var keyWords = this._key
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var keySize = keyWords.length
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var nRounds = keySize + 6
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var ksRows = (nRounds + 1) * 4
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var keySchedule = []
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for (var k = 0; k < keySize; k++) {
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keySchedule[k] = keyWords[k]
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}
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for (k = keySize; k < ksRows; k++) {
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var t = keySchedule[k - 1]
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if (k % keySize === 0) {
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t = (t << 8) | (t >>> 24)
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t =
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(G.SBOX[t >>> 24] << 24) |
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(G.SBOX[(t >>> 16) & 0xff] << 16) |
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(G.SBOX[(t >>> 8) & 0xff] << 8) |
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(G.SBOX[t & 0xff])
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t ^= RCON[(k / keySize) | 0] << 24
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} else if (keySize > 6 && k % keySize === 4) {
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t =
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(G.SBOX[t >>> 24] << 24) |
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(G.SBOX[(t >>> 16) & 0xff] << 16) |
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(G.SBOX[(t >>> 8) & 0xff] << 8) |
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(G.SBOX[t & 0xff])
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}
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keySchedule[k] = keySchedule[k - keySize] ^ t
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}
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var invKeySchedule = []
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for (var ik = 0; ik < ksRows; ik++) {
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var ksR = ksRows - ik
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var tt = keySchedule[ksR - (ik % 4 ? 0 : 4)]
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if (ik < 4 || ksR <= 4) {
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invKeySchedule[ik] = tt
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} else {
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invKeySchedule[ik] =
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G.INV_SUB_MIX[0][G.SBOX[tt >>> 24]] ^
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G.INV_SUB_MIX[1][G.SBOX[(tt >>> 16) & 0xff]] ^
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G.INV_SUB_MIX[2][G.SBOX[(tt >>> 8) & 0xff]] ^
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G.INV_SUB_MIX[3][G.SBOX[tt & 0xff]]
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}
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}
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this._nRounds = nRounds
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this._keySchedule = keySchedule
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this._invKeySchedule = invKeySchedule
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}
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AES.prototype.encryptBlockRaw = function (M) {
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M = asUInt32Array(M)
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return cryptBlock(M, this._keySchedule, G.SUB_MIX, G.SBOX, this._nRounds)
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}
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AES.prototype.encryptBlock = function (M) {
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var out = this.encryptBlockRaw(M)
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var buf = Buffer.allocUnsafe(16)
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buf.writeUInt32BE(out[0], 0)
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buf.writeUInt32BE(out[1], 4)
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buf.writeUInt32BE(out[2], 8)
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buf.writeUInt32BE(out[3], 12)
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return buf
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}
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AES.prototype.decryptBlock = function (M) {
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M = asUInt32Array(M)
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// swap
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var m1 = M[1]
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M[1] = M[3]
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M[3] = m1
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var out = cryptBlock(M, this._invKeySchedule, G.INV_SUB_MIX, G.INV_SBOX, this._nRounds)
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var buf = Buffer.allocUnsafe(16)
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buf.writeUInt32BE(out[0], 0)
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buf.writeUInt32BE(out[3], 4)
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buf.writeUInt32BE(out[2], 8)
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buf.writeUInt32BE(out[1], 12)
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return buf
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}
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AES.prototype.scrub = function () {
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scrubVec(this._keySchedule)
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scrubVec(this._invKeySchedule)
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scrubVec(this._key)
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}
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module.exports.AES = AES
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