fix: return valid values on multi-byte-wide TypedArray input

Author: ChALkeR

.eslintrc

@@ -7,6 +7,11 @@
     "func-style": "off",
   },
 
+  "globals": {
+    "Uint8Array": false,
+    "Uint16Array": false
+  },
+
   "overrides": [
     {
       "files": [

index.js

@@ -22,8 +22,42 @@ function CipherBase(hashMode) {
 }
 inherits(CipherBase, Transform);
 
+var useUint8Array = typeof Uint8Array !== 'undefined';
+var useArrayBuffer = typeof ArrayBuffer !== 'undefined'
+	&& typeof Uint8Array !== 'undefined'
+	&& ArrayBuffer.isView
+	&& (Buffer.prototype instanceof Uint8Array || Buffer.TYPED_ARRAY_SUPPORT);
+
 CipherBase.prototype.update = function (data, inputEnc, outputEnc) {
-	var bufferData = typeof data === 'string' ? Buffer.from(data, inputEnc) : data;
+	var bufferData;
+	if (data instanceof Buffer) {
+		// No need to do anything
+		bufferData = data;
+	} else if (typeof data === 'string') {
+		// Convert strings to Buffer
+		bufferData = Buffer.from(data, inputEnc);
+	} else if (useArrayBuffer && ArrayBuffer.isView(data)) {
+		/*
+		 * Wrap any TypedArray instances and DataViews
+		 * Makes sense only on engines with full TypedArray support -- let Buffer detect that
+		 */
+		bufferData = Buffer.from(data.buffer, data.byteOffset, data.byteLength);
+	} else if (useUint8Array && data instanceof Uint8Array) {
+		/*
+		 * Uint8Array in engines where Buffer.from might not work with ArrayBuffer, just copy over
+		 * Doesn't make sense with other TypedArray instances
+		 */
+		bufferData = Buffer.from(data);
+	} else if (Buffer.isBuffer(data) && data.consructor && data.consructor.isBuffer && data.consructor.isBuffer(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
+		 */
+		bufferData = Buffer.from(data);
+	} else {
+		throw new Error('The "data" argument must be of type string or an instance of Buffer, TypedArray, or DataView.');
+	}
 
 	var outData = this._update(bufferData);
 	if (this.hashMode) {

test/index.js

@@ -128,3 +128,28 @@ test('encodings', function (t) {
 		st.equals(txt, enc);
 	});
 });
+
+test('handle UInt16Array', function (t) {
+	function Cipher() {
+		CipherBase.call(this, 'finalName');
+		this._cache = [];
+	}
+	inherits(Cipher, CipherBase);
+	Cipher.prototype._update = function (input) {
+		t.ok(Buffer.isBuffer(input));
+		this._cache.push(input);
+	};
+	Cipher.prototype._final = function () {
+		return Buffer.concat(this._cache);
+	};
+
+	if (ArrayBuffer.isView && (Buffer.prototype instanceof Uint8Array || Buffer.TYPED_ARRAY_SUPPORT)) {
+		var cipher = new Cipher();
+		var final = cipher.update(new Uint16Array([1234, 512])).finalName('hex');
+		t.equals(final, 'd2040002');
+	} else {
+		t.skip('ArrayBuffer.isView and/or TypedArray not fully supported');
+	}
+
+	t.end();
+});