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