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