139 lines
4.0 KiB
JavaScript
139 lines
4.0 KiB
JavaScript
'use strict'
|
|
var Buffer = require('safe-buffer').Buffer
|
|
var Transform = require('stream').Transform
|
|
var inherits = require('inherits')
|
|
|
|
function HashBase (blockSize) {
|
|
Transform.call(this)
|
|
|
|
this._block = Buffer.allocUnsafe(blockSize)
|
|
this._blockSize = blockSize
|
|
this._blockOffset = 0
|
|
this._length = [0, 0, 0, 0]
|
|
|
|
this._finalized = false
|
|
}
|
|
|
|
inherits(HashBase, Transform)
|
|
|
|
HashBase.prototype._transform = function (chunk, encoding, callback) {
|
|
var error = null
|
|
try {
|
|
this.update(chunk, encoding)
|
|
} catch (err) {
|
|
error = err
|
|
}
|
|
|
|
callback(error)
|
|
}
|
|
|
|
HashBase.prototype._flush = function (callback) {
|
|
var error = null
|
|
try {
|
|
this.push(this.digest())
|
|
} catch (err) {
|
|
error = err
|
|
}
|
|
|
|
callback(error)
|
|
}
|
|
|
|
var useUint8Array = typeof Uint8Array !== 'undefined'
|
|
var useArrayBuffer = typeof ArrayBuffer !== 'undefined' &&
|
|
typeof Uint8Array !== 'undefined' &&
|
|
ArrayBuffer.isView &&
|
|
(Buffer.prototype instanceof Uint8Array || Buffer.TYPED_ARRAY_SUPPORT)
|
|
|
|
function toBuffer (data, encoding) {
|
|
// No need to do anything for exact instance
|
|
// This is only valid when safe-buffer.Buffer === buffer.Buffer, i.e. when Buffer.from/Buffer.alloc existed
|
|
if (data instanceof Buffer) return data
|
|
|
|
// Convert strings to Buffer
|
|
if (typeof data === 'string') return Buffer.from(data, encoding)
|
|
|
|
/*
|
|
* Wrap any TypedArray instances and DataViews
|
|
* Makes sense only on engines with full TypedArray support -- let Buffer detect that
|
|
*/
|
|
if (useArrayBuffer && ArrayBuffer.isView(data)) {
|
|
if (data.byteLength === 0) return Buffer.alloc(0) // Bug in Node.js <6.3.1, which treats this as out-of-bounds
|
|
var res = Buffer.from(data.buffer, data.byteOffset, data.byteLength)
|
|
// Recheck result size, as offset/length doesn't work on Node.js <5.10
|
|
// We just go to Uint8Array case if this fails
|
|
if (res.byteLength === data.byteLength) return res
|
|
}
|
|
|
|
/*
|
|
* Uint8Array in engines where Buffer.from might not work with ArrayBuffer, just copy over
|
|
* Doesn't make sense with other TypedArray instances
|
|
*/
|
|
if (useUint8Array && data instanceof Uint8Array) return Buffer.from(data)
|
|
|
|
/*
|
|
* Old Buffer polyfill on an engine that doesn't have TypedArray support
|
|
* Also, this is from a different Buffer polyfill implementation then we have, as instanceof check failed
|
|
* Convert to our current Buffer implementation
|
|
*/
|
|
if (
|
|
Buffer.isBuffer(data) &&
|
|
data.constructor &&
|
|
typeof data.constructor.isBuffer === 'function' &&
|
|
data.constructor.isBuffer(data)
|
|
) {
|
|
return Buffer.from(data)
|
|
}
|
|
|
|
throw new TypeError('The "data" argument must be of type string or an instance of Buffer, TypedArray, or DataView.')
|
|
}
|
|
|
|
HashBase.prototype.update = function (data, encoding) {
|
|
if (this._finalized) throw new Error('Digest already called')
|
|
|
|
data = toBuffer(data, encoding) // asserts correct input type
|
|
|
|
// consume data
|
|
var block = this._block
|
|
var offset = 0
|
|
while (this._blockOffset + data.length - offset >= this._blockSize) {
|
|
for (var i = this._blockOffset; i < this._blockSize;) block[i++] = data[offset++]
|
|
this._update()
|
|
this._blockOffset = 0
|
|
}
|
|
while (offset < data.length) block[this._blockOffset++] = data[offset++]
|
|
|
|
// update length
|
|
for (var j = 0, carry = data.length * 8; carry > 0; ++j) {
|
|
this._length[j] += carry
|
|
carry = (this._length[j] / 0x0100000000) | 0
|
|
if (carry > 0) this._length[j] -= 0x0100000000 * carry
|
|
}
|
|
|
|
return this
|
|
}
|
|
|
|
HashBase.prototype._update = function () {
|
|
throw new Error('_update is not implemented')
|
|
}
|
|
|
|
HashBase.prototype.digest = function (encoding) {
|
|
if (this._finalized) throw new Error('Digest already called')
|
|
this._finalized = true
|
|
|
|
var digest = this._digest()
|
|
if (encoding !== undefined) digest = digest.toString(encoding)
|
|
|
|
// reset state
|
|
this._block.fill(0)
|
|
this._blockOffset = 0
|
|
for (var i = 0; i < 4; ++i) this._length[i] = 0
|
|
|
|
return digest
|
|
}
|
|
|
|
HashBase.prototype._digest = function () {
|
|
throw new Error('_digest is not implemented')
|
|
}
|
|
|
|
module.exports = HashBase
|