66 lines
1.4 KiB
JavaScript
66 lines
1.4 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 proto = {};
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function CBCState(iv) {
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assert.equal(iv.length, 8, 'Invalid IV length');
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this.iv = new Array(8);
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for (var i = 0; i < this.iv.length; i++)
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this.iv[i] = iv[i];
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}
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function instantiate(Base) {
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function CBC(options) {
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Base.call(this, options);
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this._cbcInit();
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}
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inherits(CBC, Base);
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var keys = Object.keys(proto);
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for (var i = 0; i < keys.length; i++) {
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var key = keys[i];
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CBC.prototype[key] = proto[key];
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}
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CBC.create = function create(options) {
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return new CBC(options);
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};
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return CBC;
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}
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exports.instantiate = instantiate;
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proto._cbcInit = function _cbcInit() {
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var state = new CBCState(this.options.iv);
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this._cbcState = state;
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};
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proto._update = function _update(inp, inOff, out, outOff) {
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var state = this._cbcState;
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var superProto = this.constructor.super_.prototype;
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var iv = state.iv;
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if (this.type === 'encrypt') {
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for (var i = 0; i < this.blockSize; i++)
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iv[i] ^= inp[inOff + i];
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superProto._update.call(this, iv, 0, out, outOff);
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for (var i = 0; i < this.blockSize; i++)
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iv[i] = out[outOff + i];
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} else {
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superProto._update.call(this, inp, inOff, out, outOff);
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for (var i = 0; i < this.blockSize; i++)
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out[outOff + i] ^= iv[i];
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for (var i = 0; i < this.blockSize; i++)
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iv[i] = inp[inOff + i];
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}
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};
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