Current Dev State

static/js/ketcher2/node_modules/des.js/lib/des/des.js

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+'use strict';
+
+var assert = require('minimalistic-assert');
+var inherits = require('inherits');
+
+var des = require('../des');
+var utils = des.utils;
+var Cipher = des.Cipher;
+
+function DESState() {
+  this.tmp = new Array(2);
+  this.keys = null;
+}
+
+function DES(options) {
+  Cipher.call(this, options);
+
+  var state = new DESState();
+  this._desState = state;
+
+  this.deriveKeys(state, options.key);
+}
+inherits(DES, Cipher);
+module.exports = DES;
+
+DES.create = function create(options) {
+  return new DES(options);
+};
+
+var shiftTable = [
+  1, 1, 2, 2, 2, 2, 2, 2,
+  1, 2, 2, 2, 2, 2, 2, 1
+];
+
+DES.prototype.deriveKeys = function deriveKeys(state, key) {
+  state.keys = new Array(16 * 2);
+
+  assert.equal(key.length, this.blockSize, 'Invalid key length');
+
+  var kL = utils.readUInt32BE(key, 0);
+  var kR = utils.readUInt32BE(key, 4);
+
+  utils.pc1(kL, kR, state.tmp, 0);
+  kL = state.tmp[0];
+  kR = state.tmp[1];
+  for (var i = 0; i < state.keys.length; i += 2) {
+    var shift = shiftTable[i >>> 1];
+    kL = utils.r28shl(kL, shift);
+    kR = utils.r28shl(kR, shift);
+    utils.pc2(kL, kR, state.keys, i);
+  }
+};
+
+DES.prototype._update = function _update(inp, inOff, out, outOff) {
+  var state = this._desState;
+
+  var l = utils.readUInt32BE(inp, inOff);
+  var r = utils.readUInt32BE(inp, inOff + 4);
+
+  // Initial Permutation
+  utils.ip(l, r, state.tmp, 0);
+  l = state.tmp[0];
+  r = state.tmp[1];
+
+  if (this.type === 'encrypt')
+    this._encrypt(state, l, r, state.tmp, 0);
+  else
+    this._decrypt(state, l, r, state.tmp, 0);
+
+  l = state.tmp[0];
+  r = state.tmp[1];
+
+  utils.writeUInt32BE(out, l, outOff);
+  utils.writeUInt32BE(out, r, outOff + 4);
+};
+
+DES.prototype._pad = function _pad(buffer, off) {
+  var value = buffer.length - off;
+  for (var i = off; i < buffer.length; i++)
+    buffer[i] = value;
+
+  return true;
+};
+
+DES.prototype._unpad = function _unpad(buffer) {
+  var pad = buffer[buffer.length - 1];
+  for (var i = buffer.length - pad; i < buffer.length; i++)
+    assert.equal(buffer[i], pad);
+
+  return buffer.slice(0, buffer.length - pad);
+};
+
+DES.prototype._encrypt = function _encrypt(state, lStart, rStart, out, off) {
+  var l = lStart;
+  var r = rStart;
+
+  // Apply f() x16 times
+  for (var i = 0; i < state.keys.length; i += 2) {
+    var keyL = state.keys[i];
+    var keyR = state.keys[i + 1];
+
+    // f(r, k)
+    utils.expand(r, state.tmp, 0);
+
+    keyL ^= state.tmp[0];
+    keyR ^= state.tmp[1];
+    var s = utils.substitute(keyL, keyR);
+    var f = utils.permute(s);
+
+    var t = r;
+    r = (l ^ f) >>> 0;
+    l = t;
+  }
+
+  // Reverse Initial Permutation
+  utils.rip(r, l, out, off);
+};
+
+DES.prototype._decrypt = function _decrypt(state, lStart, rStart, out, off) {
+  var l = rStart;
+  var r = lStart;
+
+  // Apply f() x16 times
+  for (var i = state.keys.length - 2; i >= 0; i -= 2) {
+    var keyL = state.keys[i];
+    var keyR = state.keys[i + 1];
+
+    // f(r, k)
+    utils.expand(l, state.tmp, 0);
+
+    keyL ^= state.tmp[0];
+    keyR ^= state.tmp[1];
+    var s = utils.substitute(keyL, keyR);
+    var f = utils.permute(s);
+
+    var t = l;
+    l = (r ^ f) >>> 0;
+    r = t;
+  }
+
+  // Reverse Initial Permutation
+  utils.rip(l, r, out, off);
+};