| 'use strict'; |
| |
| var assert = require('minimalistic-assert'); |
| var inherits = require('inherits'); |
| |
| var des = require('../des'); |
| var Cipher = des.Cipher; |
| var DES = des.DES; |
| |
| function EDEState(type, key) { |
| assert.equal(key.length, 24, 'Invalid key length'); |
| |
| var k1 = key.slice(0, 8); |
| var k2 = key.slice(8, 16); |
| var k3 = key.slice(16, 24); |
| |
| if (type === 'encrypt') { |
| this.ciphers = [ |
| DES.create({ type: 'encrypt', key: k1 }), |
| DES.create({ type: 'decrypt', key: k2 }), |
| DES.create({ type: 'encrypt', key: k3 }) |
| ]; |
| } else { |
| this.ciphers = [ |
| DES.create({ type: 'decrypt', key: k3 }), |
| DES.create({ type: 'encrypt', key: k2 }), |
| DES.create({ type: 'decrypt', key: k1 }) |
| ]; |
| } |
| } |
| |
| function EDE(options) { |
| Cipher.call(this, options); |
| |
| var state = new EDEState(this.type, this.options.key); |
| this._edeState = state; |
| } |
| inherits(EDE, Cipher); |
| |
| module.exports = EDE; |
| |
| EDE.create = function create(options) { |
| return new EDE(options); |
| }; |
| |
| EDE.prototype._update = function _update(inp, inOff, out, outOff) { |
| var state = this._edeState; |
| |
| state.ciphers[0]._update(inp, inOff, out, outOff); |
| state.ciphers[1]._update(out, outOff, out, outOff); |
| state.ciphers[2]._update(out, outOff, out, outOff); |
| }; |
| |
| EDE.prototype._pad = DES.prototype._pad; |
| EDE.prototype._unpad = DES.prototype._unpad; |