Message also accepts an ArrayBuffer

Author: Kenneth Heutmaker

lib/message.js

@@ -22,7 +22,9 @@ var Message = function Message(message) {
   if (!(this instanceof Message)) {
     return new Message(message);
   }
-  $.checkArgument(_.isString(message) || message instanceof Buffer,
+  // When lodash is updated to v4.3.0 or better, change this to _.isBuffer and _.isArrayBuffer
+  $.checkArgument(_.isString(message) || (Buffer && Buffer.isBuffer(message)) ||
+    (message instanceof Object && message.toString() === "[object ArrayBuffer]"),
     'First argument must be a string or Buffer');
   this.message = message;
 
@@ -33,8 +35,7 @@ Message.MAGIC_BYTES = new Buffer('Bitcoin Signed Message:\n');
 
 Message.prototype.magicHash = function magicHash() {
   var prefix1 = BufferWriter.varintBufNum(Message.MAGIC_BYTES.length);
-  var messageBuffer = this.message instanceof Buffer ?
-    this.message : new Buffer(this.message);
+  var messageBuffer = new Buffer(this.message);
   var prefix2 = BufferWriter.varintBufNum(messageBuffer.length);
   var buf = Buffer.concat([prefix1, Message.MAGIC_BYTES, prefix2, messageBuffer]);
   var hash = sha256sha256(buf);