[Fix] return valid values on multi-byte-wide TypedArray input

Author: ChALkeR

index.js

@@ -3,12 +3,6 @@ var Buffer = require('safe-buffer').Buffer
 var Transform = require('stream').Transform
 var inherits = require('inherits')
 
-function throwIfNotStringOrBuffer (val, prefix) {
-  if (!Buffer.isBuffer(val) && typeof val !== 'string') {
-    throw new TypeError(prefix + ' must be a string or a buffer')
-  }
-}
-
 function HashBase (blockSize) {
   Transform.call(this)
 
@@ -44,10 +38,56 @@ HashBase.prototype._flush = function (callback) {
   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 v5.12, 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) {
-  throwIfNotStringOrBuffer(data, 'Data')
   if (this._finalized) throw new Error('Digest already called')
-  if (!Buffer.isBuffer(data)) data = Buffer.from(data, encoding)
+
+  data = toBuffer(data, encoding) // asserts correct input type
 
   // consume data
   var block = this._block

test/index.js

@@ -77,7 +77,7 @@ test('HashBase#update', function (t) {
   t.test('only string or buffer is allowed', function (t) {
     t.throws(function () {
       t.base.update(null)
-    }, /^TypeError: Data must be a string or a buffer$/)
+    }, /^TypeError: The "data" argument must be of type string or an instance of Buffer, TypedArray, or DataView.$/)
     t.end()
   })
 
@@ -128,6 +128,20 @@ test('HashBase#update', function (t) {
     t.end()
   })
 
+  t.test('handle UInt16Array', function (t) {
+    beforeEach(t, createHashBase)
+
+    if (ArrayBuffer.isView && (Buffer.prototype instanceof Uint8Array || Buffer.TYPED_ARRAY_SUPPORT)) {
+      t.base._update = noop
+      t.base.update(new Uint16Array([1234, 512]))
+      t.same(t.base._block.slice(0, t.base._blockOffset), Buffer.from('d2040002', 'hex'))
+    } else {
+      t.skip('ArrayBuffer.isView and/or TypedArray not fully supported')
+    }
+
+    t.end()
+  })
+
   t.end()
 })