crypto: make randomBytes() compatible with domains

Don't execute the callback in the context of the global object.

MakeCallback() tries to apply the active domain to the callback. If the user
polluted the global object with a 'domain' property, as in the code example
below, MakeCallback() will try to apply that.

Example:

    domain = {};                // missing var keyword is intentional
    crypto.randomBytes(8, cb);  // TypeError: undefined is not a function

Fixes #3956.

src/node_crypto.cc

@@ -4354,7 +4354,7 @@ typedef int (*RandomBytesGenerator)(unsigned char* buf, int size);
 
 struct RandomBytesRequest {
   ~RandomBytesRequest();
-  Persistent<Function> callback_;
+  Persistent<Object> obj_;
   unsigned long error_; // openssl error code or zero
   uv_work_t work_req_;
   size_t size_;
@@ -4363,10 +4363,9 @@ struct RandomBytesRequest {
 
 
 RandomBytesRequest::~RandomBytesRequest() {
-  if (!callback_.IsEmpty()) {
-    callback_.Dispose();
-    callback_.Clear();
-  }
+  if (obj_.IsEmpty()) return;
+  obj_.Dispose();
+  obj_.Clear();
 }
 
 
@@ -4427,12 +4426,7 @@ void RandomBytesAfter(uv_work_t* work_req) {
   HandleScope scope;
   Local<Value> argv[2];
   RandomBytesCheck(req, argv);
-
-  // XXX There should be an object connected to this that
-  // we can attach a domain onto.
-  MakeCallback(Context::GetCurrent()->Global(),
-               req->callback_,
-               ARRAY_SIZE(argv), argv);
+  MakeCallback(req->obj_, "ondone", ARRAY_SIZE(argv), argv);
 
   delete req;
 }
@@ -4457,15 +4451,15 @@ Handle<Value> RandomBytes(const Arguments& args) {
   req->size_ = size;
 
   if (args[1]->IsFunction()) {
-    Local<Function> callback_v = Local<Function>(Function::Cast(*args[1]));
-    req->callback_ = Persistent<Function>::New(callback_v);
+    req->obj_ = Persistent<Object>::New(Object::New());
+    req->obj_->Set(String::New("ondone"), args[1]);
 
     uv_queue_work(uv_default_loop(),
                   &req->work_req_,
                   RandomBytesWork<generator>,
                   RandomBytesAfter<generator>);
 
-    return Undefined();
+    return req->obj_;
   }
   else {
     Local<Value> argv[2];

test/simple/test-domain-crypto.js

@@ -0,0 +1,36 @@
+// Copyright Joyent, Inc. and other Node contributors.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a
+// copy of this software and associated documentation files (the
+// "Software"), to deal in the Software without restriction, including
+// without limitation the rights to use, copy, modify, merge, publish,
+// distribute, sublicense, and/or sell copies of the Software, and to permit
+// persons to whom the Software is furnished to do so, subject to the
+// following conditions:
+//
+// The above copyright notice and this permission notice shall be included
+// in all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
+// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
+// USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+try {
+  var crypto = require('crypto');
+} catch (e) {
+  console.log('Not compiled with OPENSSL support.');
+  process.exit();
+}
+
+// the missing var keyword is intentional
+domain = require('domain');
+
+// should not throw a 'TypeError: undefined is not a function' exception
+crypto.randomBytes(8);
+crypto.randomBytes(8, function() {});
+crypto.pseudoRandomBytes(8);
+crypto.pseudoRandomBytes(8, function() {});