104 lines
2.2 KiB
JavaScript
104 lines
2.2 KiB
JavaScript
'use strict';
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var Buffer = require('safe-buffer').Buffer;
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var Transform = require('stream').Transform;
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var StringDecoder = require('string_decoder').StringDecoder;
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var inherits = require('inherits');
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var toBuffer = require('to-buffer');
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function CipherBase(hashMode) {
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Transform.call(this);
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this.hashMode = typeof hashMode === 'string';
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if (this.hashMode) {
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this[hashMode] = this._finalOrDigest;
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} else {
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this['final'] = this._finalOrDigest;
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}
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if (this._final) {
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this.__final = this._final;
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this._final = null;
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}
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this._decoder = null;
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this._encoding = null;
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}
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inherits(CipherBase, Transform);
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CipherBase.prototype.update = function (data, inputEnc, outputEnc) {
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var bufferData = toBuffer(data, inputEnc); // asserts correct input type
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var outData = this._update(bufferData);
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if (this.hashMode) {
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return this;
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}
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if (outputEnc) {
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outData = this._toString(outData, outputEnc);
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}
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return outData;
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};
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CipherBase.prototype.setAutoPadding = function () {};
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CipherBase.prototype.getAuthTag = function () {
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throw new Error('trying to get auth tag in unsupported state');
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};
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CipherBase.prototype.setAuthTag = function () {
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throw new Error('trying to set auth tag in unsupported state');
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};
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CipherBase.prototype.setAAD = function () {
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throw new Error('trying to set aad in unsupported state');
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};
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CipherBase.prototype._transform = function (data, _, next) {
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var err;
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try {
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if (this.hashMode) {
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this._update(data);
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} else {
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this.push(this._update(data));
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}
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} catch (e) {
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err = e;
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} finally {
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next(err);
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}
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};
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CipherBase.prototype._flush = function (done) {
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var err;
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try {
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this.push(this.__final());
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} catch (e) {
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err = e;
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}
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done(err);
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};
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CipherBase.prototype._finalOrDigest = function (outputEnc) {
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var outData = this.__final() || Buffer.alloc(0);
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if (outputEnc) {
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outData = this._toString(outData, outputEnc, true);
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}
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return outData;
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};
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CipherBase.prototype._toString = function (value, enc, fin) {
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if (!this._decoder) {
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this._decoder = new StringDecoder(enc);
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this._encoding = enc;
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}
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if (this._encoding !== enc) {
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throw new Error('can’t switch encodings');
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}
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var out = this._decoder.write(value);
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if (fin) {
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out += this._decoder.end();
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}
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return out;
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};
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module.exports = CipherBase;
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