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yakovenkodenis/DES.js

Created May 26, 2016 15:29
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ES6 DES implementation (with PKCS7 padding)
Raw
DES.js
export default class DES {
_initial_permutation = [
58, 50, 42, 34, 26, 18, 10, 2,
60, 52, 44, 36, 28, 20, 12, 4,
62, 54, 46, 38, 30, 22, 14, 6,
64, 56, 48, 40, 32, 24, 16, 8,
57, 49, 41, 33, 25, 17, 9, 1,
59, 51, 43, 35, 27, 19, 11, 3,
61, 53, 45, 37, 29, 21, 13, 5,
63, 55, 47, 39, 31, 23, 15, 7
]
_final_permutation = [
40, 8, 48, 16, 56, 24, 64, 32,
39, 7, 47, 15, 55, 23, 63, 31,
38, 6, 46, 14, 54, 22, 62, 30,
37, 5, 45, 13, 53, 21, 61, 29,
36, 4, 44, 12, 52, 20, 60, 28,
35, 3, 43, 11, 51, 19, 59, 27,
34, 2, 42, 10, 50, 18, 58, 26,
33, 1, 41, 9, 49, 17, 57, 25
]
_expansion_function = [
32, 1, 2, 3, 4, 5,
4, 5, 6, 7, 8, 9,
8, 9, 10, 11, 12, 13,
12, 13, 14, 15, 16, 17,
16, 17, 18, 19, 20, 21,
20, 21, 22, 23, 24, 25,
24, 25, 26, 27, 28, 29,
28, 29, 30, 31, 32, 1
]
_permutation = [
16, 7, 20, 21, 29, 12, 28, 17,
1, 15, 23, 26, 5, 18, 31, 10,
2, 8, 24, 14, 32, 27, 3, 9,
19, 13, 30, 6, 22, 11, 4, 25
]
_pc1 = [
57, 49, 41, 33, 25, 17, 9,
1, 58, 50, 42, 34, 26, 18,
10, 2, 59, 51, 43, 35, 27,
19, 11, 3, 60, 52, 44, 36,
63, 55, 47, 39, 31, 23, 15,
7, 62, 54, 46, 38, 30, 22,
14, 6, 61, 53, 45, 37, 29,
21, 13, 5, 28, 20, 12, 4
]
_pc2 = [
14, 17, 11, 24, 1, 5,
3, 28, 15, 6, 21, 10,
23, 19, 12, 4, 26, 8,
16, 7, 27, 20, 13, 2,
41, 52, 31, 37, 47, 55,
30, 40, 51, 45, 33, 48,
44, 49, 39, 56, 34, 53,
46, 42, 50, 36, 29, 32
]
_left_rotations = [
1, 1, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 1
]
_sbox = [
// S1
[
[14, 4, 13, 1, 2, 15, 11, 8, 3, 10, 6, 12, 5, 9, 0, 7],
[0, 15, 7, 4, 14, 2, 13, 1, 10, 6, 12, 11, 9, 5, 3, 8],
[4, 1, 14, 8, 13, 6, 2, 11, 15, 12, 9, 7, 3, 10, 5, 0],
[15, 12, 8, 2, 4, 9, 1, 7, 5, 11, 3, 14, 10, 0, 6, 13]
],
// S2
[
[15, 1, 8, 14, 6, 11, 3, 4, 9, 7, 2, 13, 12, 0, 5, 10],
[3, 13, 4, 7, 15, 2, 8, 14, 12, 0, 1, 10, 6, 9, 11, 5],
[0, 14, 7, 11, 10, 4, 13, 1, 5, 8, 12, 6, 9, 3, 2, 15],
[13, 8, 10, 1, 3, 15, 4, 2, 11, 6, 7, 12, 0, 5, 14, 9]
],
// S3
[
[10, 0, 9, 14, 6, 3, 15, 5, 1, 13, 12, 7, 11, 4, 2, 8],
[13, 7, 0, 9, 3, 4, 6, 10, 2, 8, 5, 14, 12, 11, 15, 1],
[13, 6, 4, 9, 8, 15, 3, 0, 11, 1, 2, 12, 5, 10, 14, 7],
[1, 10, 13, 0, 6, 9, 8, 7, 4, 15, 14, 3, 11, 5, 2, 12]
],
// S4
[
[7, 13, 14, 3, 0, 6, 9, 10, 1, 2, 8, 5, 11, 12, 4, 15],
[13, 8, 11, 5, 6, 15, 0, 3, 4, 7, 2, 12, 1, 10, 14, 9],
[10, 6, 9, 0, 12, 11, 7, 13, 15, 1, 3, 14, 5, 2, 8, 4],
[3, 15, 0, 6, 10, 1, 13, 8, 9, 4, 5, 11, 12, 7, 2, 14]
],
// S5
[
[2, 12, 4, 1, 7, 10, 11, 6, 8, 5, 3, 15, 13, 0, 14, 9],
[14, 11, 2, 12, 4, 7, 13, 1, 5, 0, 15, 10, 3, 9, 8, 6],
[4, 2, 1, 11, 10, 13, 7, 8, 15, 9, 12, 5, 6, 3, 0, 14],
[11, 8, 12, 7, 1, 14, 2, 13, 6, 15, 0, 9, 10, 4, 5, 3]
],
// S6
[
[12, 1, 10, 15, 9, 2, 6, 8, 0, 13, 3, 4, 14, 7, 5, 11],
[10, 15, 4, 2, 7, 12, 9, 5, 6, 1, 13, 14, 0, 11, 3, 8],
[9, 14, 15, 5, 2, 8, 12, 3, 7, 0, 4, 10, 1, 13, 11, 6],
[4, 3, 2, 12, 9, 5, 15, 10, 11, 14, 1, 7, 6, 0, 8, 13]
],
// S7
[
[4, 11, 2, 14, 15, 0, 8, 13, 3, 12, 9, 7, 5, 10, 6, 1],
[13, 0, 11, 7, 4, 9, 1, 10, 14, 3, 5, 12, 2, 15, 8, 6],
[1, 4, 11, 13, 12, 3, 7, 14, 10, 15, 6, 8, 0, 5, 9, 2],
[6, 11, 13, 8, 1, 4, 10, 7, 9, 5, 0, 15, 14, 2, 3, 12]
],
// S8
[
[13, 2, 8, 4, 6, 15, 11, 1, 10, 9, 3, 14, 5, 0, 12, 7],
[1, 15, 13, 8, 10, 3, 7, 4, 12, 5, 6, 11, 0, 14, 9, 2],
[7, 11, 4, 1, 9, 12, 14, 2, 0, 6, 10, 13, 15, 3, 5, 8],
[2, 1, 14, 7, 4, 10, 8, 13, 15, 12, 9, 0, 3, 5, 6, 11]
]
]
constructor(key) {
this.key = key;
}
encrypt(message) {
let padded = this.pkcs7Padding(message),
result = [];
for (let block of padded) {
result = result.concat(this.encrypt64bit(block.join('')));
}
return result;
}
decrypt(message, msgInBits=false) {
let bitsArrayMsg;
if (msgInBits) {
bitsArrayMsg = message;
} else {
bitsArrayMsg = this._stringToBitsArray(message);
}
if (bitsArrayMsg.length % 64 !== 0) {
throw new Error('Ciphered code can only be a multiple of 64');
}
let blocksLst = this._chunkify(bitsArrayMsg, 64, true, 64);
let result = [];
for (let block of blocksLst) {
let decrypted = this.decrypt64bit(block, true),
bl = this._bitsArrayToCharArray(decrypted);
result = result.concat(this._unpad(bl));
}
return result.join('');
}
encrypt64bit(message) {
return this.crypt(message, true, false);
}
decrypt64bit(message, msgInBits=false) {
return this.crypt(message, false, msgInBits);
}
crypt(message, encrypt=true, msgInBits=false) {
let bitsArrayMsg;
if (msgInBits) {
bitsArrayMsg = message;
} else {
bitsArrayMsg = this._stringToBitsArray(message);
}
let bitsArrayKey = this._stringToBitsArray(this.key);
if (bitsArrayMsg.length != 64) {
throw new Error('Message must be 64 bit!');
}
if (bitsArrayKey.length != 64) {
throw new Error('Key must be 64 bit!');
}
// Compute 16 48-bit subkeys
let subkeys = this.getSubkeys(bitsArrayKey);
// Convert the message using the initial permutation block
let msg = [];
for (let i of this._initial_permutation) {
msg.push(bitsArrayMsg[i - 1]);
}
let L = msg.slice(0, 32),
R = msg.slice(32);
if (encrypt) {
for (let i = 0; i < 16; ++i) {
let prevR = R;
let rFeistel = this.feistelFunction(R, subkeys[i]);
R = [];
for (let j = 0; j < 32; ++j) {
R.push(L[j] ^ rFeistel[j]);
}
L = prevR;
}
} else {
for (let i = 15; i >= 0; --i) {
let prevL = L;
let lFeistel = this.feistelFunction(L, subkeys[i]);
L = [];
for (let j = 0; j < 32; ++j) {
L.push(R[j] ^ lFeistel[j]);
}
R = prevL;
}
}
let beforeFinalPermute = L.concat(R);
// compute final permutation
let finalPermute = [];
for (let i of this._final_permutation) {
finalPermute.push(beforeFinalPermute[i - 1]);
}
return finalPermute;
}
pkcs7Padding(message, blockSize = 8, pad=true) {
let msg = message.split(''),
blocksLst = this._chunkify(msg, blockSize, true, blockSize);
if (pad) {
let s = blockSize;
return blocksLst
.map(b => b.length < s ? this._pad(b, s) : b);
} else {
return blocksLst;
}
}
feistelFunction(r32bit, subkey48bit) {
let r48bit = [];
for (let i of this._expansion_function) {
r48bit.push(r32bit[i - 1]);
}
let subkeyXorR = [];
for (let i = 0; i < 48; ++i) {
subkeyXorR.push(r48bit[i] ^ subkey48bit[i]);
}
// Divide subkeyXorR into 8 6-bit blocks for computing s-boxes
let b6bitBlocks = this._chunkify(subkeyXorR, 8);
let afterSboxes32bit = [];
for (let i = 0; i < 8; ++i) {
afterSboxes32bit = afterSboxes32bit.concat(
this.computeSBox(this._sbox[i], b6bitBlocks[i])
);
}
// Compute the permutation and return the 32-bit block
let res32bit = [];
for (let i of this._permutation) {
res32bit.push(afterSboxes32bit[i - 1]);
}
return res32bit;
}
computeSBox(sbox, b6bit) {
let row = parseInt(b6bit[0] + '' + b6bit[5], 2),
col = parseInt(b6bit.slice(1, 5).join(''), 2);
const sboxRes = sbox[row][col];
return this._createBinaryString(sboxRes)
.substr(28).split('')
.map(i => parseInt(i));
}
getSubkeys(bitsArrayKey) {
// Compute Permuted Choice 1 on the key
let key56bit = []
for (let i of this._pc1) {
key56bit.push(bitsArrayKey[i-1]);
}
// Split the key into two 28-bit subkeys
let key56left = key56bit.slice(0, 28),
key56right = key56bit.slice(28);
// Compute 16 48-bit keys using left rotations and permuted choice 2
let subkeys48bit = [];
let C = key56left, D = key56right;
for (let i = 0; i < 16; ++i) {
C = this._arrayLeftRotate(C, this._left_rotations[i]);
D = this._arrayLeftRotate(D, this._left_rotations[i]);
let CD = C.concat(D);
let CDres = []
for (let j of this._pc2) {
CDres.push(CD[j-1]);
}
subkeys48bit.push(CDres);
}
return subkeys48bit;
}
_stringToBitsArray(str) {
return this._stringToByteArray(str)
.map(i => this._createBinaryString(i).substr(24))
.map(i => i.split(''))
.reduce((i1, i2) => i1.concat(i2))
.map(i => parseInt(i));
}
_bitsArrayToCharArray(arr) {
return this._chunkify(arr, 8, true, 8)
.map(b => parseInt(b.join(''), 2))
.map(c => String.fromCharCode(c));
}
_stringToByteArray(str) {
let byteArray = [],
len = str.length,
i = 0;
for (i; i < len; ++i) {
byteArray.push(str.charCodeAt(i));
}
return byteArray;
}
_createBinaryString(nMask) {
for (var nFlag = 0, nShifted = nMask, sMask = ''; nFlag < 32;
nFlag++, sMask += String(nShifted >>> 31), nShifted <<= 1);
return sMask;
}
_arrayLeftRotate(arr, rotations=1) {
for (let i = 0; i < rotations; ++i) {
arr = this._arrayLeftShift(arr);
}
return arr;
}
_arrayLeftShift(arr) {
let temp = new Array(),
len = arr.length - 1,
i = 1;
for (i; i <= len; ++i) {
temp.push(arr[i]);
}
temp.push(arr[0]);
return temp;
}
_chunkify(a, n, balanced, chunkSize) {
if (!isNaN(chunkSize)) {
return a.map(
(e, i) => i % chunkSize === 0 ? a.slice(i, i + chunkSize) : null
).filter(e => e);
}
if (n < 2) {
return [a];
}
let len = a.length,
out = [],
i = 0,
size;
if (len % n === 0) {
size = Math.floor(len / n);
while (i < len) {
out.push(a.slice(i, i += size));
}
}
else if (balanced) {
while (i < len) {
size = Math.ceil((len - i) / n--);
out.push(a.slice(i, i += size));
}
}
else {
n--;
size = Math.floor(len / n);
if (len % size === 0)
size--;
while (i < size * n) {
out.push(a.slice(i, i += size));
}
out.push(a.slice(size * n));
}
return out;
}
_pad(arr, blockSize) {
let z = blockSize - arr.length;
return arr.concat(Array(z).fill(z));
}
_unpad(arr) {
let last = arr[arr.length - 1];
if (!isNaN(last)) {
let arrStr = arr.join('');
let i = +last, j = i;
while (arrStr[arrStr.length - 1] === j.toString() && i > 0) {
arrStr = arrStr.slice(0, -1);
i--;
}
return arrStr.split('');
} else {
return arr;
}
}
}
Raw
DES_test.js
import DES from './DES';
let d = new DES('qwertyui');
// let cipher = d.encrypt64bit('heleo we')
// console.log(cipher);
// let decipheredBits = d.decrypt64bit(cipher, true);
// console.log(decipheredBits.length);
// console.log(decipheredBits);
let cipher = d.encrypt('hello world!');
// console.log(cipher);
let deciphered = d.decrypt(cipher, true);
console.log(deciphered);
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