�PNG  IHDR��;���IDATx��ܻn�0���K�� �)(�pA��� ���7�LeG{�� �§㻢|��ذaÆ 6lذaÆ 6lذaÆ 6lom��$^�y���ذag�5bÆ 6lذaÆ 6lذa{���� 6lذaÆ �`����}H�Fkm�,�m����Ӫ���ô�ô!� �x�|'ܢ˟;�E:���9�&ᶒ�}�{�v]�n&�6� �h��_��t�ڠ͵-ҫ���Z;��Z$�.�P���k�ž)�!��o���>}l�eQfJ�T��u і���چ��\��X=8��Rن4`Vw�l�>����n�G�^��i�s��"ms�$�u��i��?w�bs[m�6�K4���O���.�4��%����/����b�C%��t ��M�ז� �-l�G6�mrz2���s�%�9��s@���-�k�9�=���)������k�B5����\��+͂�Zsٲ ��Rn��~G���R���C����� �wIcI��n7jJ���hۛNCS|���j0��8y�iHKֶۛ�k�Ɉ+;Sz������L/��F�*\��Ԕ�#"5��m�2��[S��������=�g��n�a�P�e�ғ�L�� lذaÆ 6l�^k��̱aÆ 6lذaÆ 6lذa;���� �_��ذaÆ 6lذaÆ 6lذaÆ ���R���IEND�B` 'use strict'; var assert = require('minimalistic-assert'); var inherits = require('inherits'); var utils = require('./utils'); var Cipher = require('./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); };