wallet-core/node_modules/cipher-base/index.js

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2017-05-03 15:35:00 +02:00
var Transform = require('stream').Transform
var inherits = require('inherits')
var StringDecoder = require('string_decoder').StringDecoder
module.exports = CipherBase
inherits(CipherBase, Transform)
function CipherBase (hashMode) {
Transform.call(this)
this.hashMode = typeof hashMode === 'string'
if (this.hashMode) {
this[hashMode] = this._finalOrDigest
} else {
this.final = this._finalOrDigest
}
this._decoder = null
this._encoding = null
}
CipherBase.prototype.update = function (data, inputEnc, outputEnc) {
if (typeof data === 'string') {
data = new Buffer(data, inputEnc)
}
var outData = this._update(data)
if (this.hashMode) {
return this
}
if (outputEnc) {
outData = this._toString(outData, outputEnc)
}
return outData
}
CipherBase.prototype.setAutoPadding = function () {}
CipherBase.prototype.getAuthTag = function () {
throw new Error('trying to get auth tag in unsupported state')
}
CipherBase.prototype.setAuthTag = function () {
throw new Error('trying to set auth tag in unsupported state')
}
CipherBase.prototype.setAAD = function () {
throw new Error('trying to set aad in unsupported state')
}
CipherBase.prototype._transform = function (data, _, next) {
var err
try {
if (this.hashMode) {
this._update(data)
} else {
this.push(this._update(data))
}
} catch (e) {
err = e
} finally {
next(err)
}
}
CipherBase.prototype._flush = function (done) {
var err
try {
this.push(this._final())
} catch (e) {
err = e
} finally {
done(err)
}
}
CipherBase.prototype._finalOrDigest = function (outputEnc) {
var outData = this._final() || new Buffer('')
if (outputEnc) {
outData = this._toString(outData, outputEnc, true)
}
return outData
}
CipherBase.prototype._toString = function (value, enc, fin) {
if (!this._decoder) {
this._decoder = new StringDecoder(enc)
this._encoding = enc
}
if (this._encoding !== enc) {
throw new Error('can\'t switch encodings')
}
var out = this._decoder.write(value)
if (fin) {
out += this._decoder.end()
}
return out
}