Partial implementation of subscription restrictions.

third_party/WebKit/Source/modules/push_messaging/PushManager.cpp

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "modules/push_messaging/PushManager.h"
 
 #include "bindings/core/v8/ScriptPromise.h"
 #include "bindings/core/v8/ScriptPromiseResolver.h"
 #include "bindings/core/v8/ScriptState.h"
 #include "core/dom/DOMException.h"
@@ skipping 16 matching lines @@
 namespace blink {
 namespace {
 
 WebPushProvider* pushProvider()
 {
     WebPushProvider* webPushProvider = Platform::current()->pushProvider();
     ASSERT(webPushProvider);
     return webPushProvider;
 }
 
-WebPushSubscriptionOptions toWebPushSubscriptionOptions(const PushSubscriptionOptions& options)
-{
-    WebPushSubscriptionOptions webOptions;
-    webOptions.userVisibleOnly = options.userVisibleOnly();
-    return webOptions;
-}
-
 } // namespace
 
 PushManager::PushManager(ServiceWorkerRegistration* registration)
     : m_registration(registration)
 {
     ASSERT(registration);
 }
 
+String PushManager::toString(const ArrayBufferOrArrayBufferView& applicationServerKey)
+{
+    // Check the validity of the sender info. It should either be a numeric sender
+    // ID or a 65 byte unencrypted key.

[Peter Beverloo, 2016/02/23 14:28:29]

Developers will have two ways in Chrome to provide their keys.

(1) The new standardized way (SubscriptionOptions.applicationServerKey). This
*must* be a valid point on the P-256 curve, i.e. a 65-byte sequence starting
with 0x04.

https://github.com/w3c/push-api/pull/182/files

Accepting sender Ids in this property as well would mean that we violate the
spec, and also limit our own ability to use this as a carrot for moving to the
Web Push protocol.

Put differently, we shouldn't accept a sender Id here.

(2) The existing, proprietary way (`gcm_sender_id` in the manifest). This is an
opaque string that we just forward to GCM.

We already don't care about this value, and I think there's no reason to start
caring now either.

What does matter is that we give (1) precedence over (2), and that's exactly
what this CL does in the PushMessagingMessageFilter :-).

Sorry that this is confusing.

[harkness, 2016/02/26 11:44:26]

Done.

+    char* input;
+    int length;
+    if (applicationServerKey.isArrayBuffer()) {
+        input = static_cast<char*>(
+            applicationServerKey.getAsArrayBuffer()->data());
+        length = applicationServerKey.getAsArrayBuffer()->byteLength();
+    } else if (applicationServerKey.isArrayBufferView()) {
+        input = static_cast<char*>(
+            applicationServerKey.getAsArrayBufferView()->buffer()->data());
+        length = applicationServerKey.getAsArrayBufferView()->buffer()->byteLength();
+    } else {
+        return String();

[Peter Beverloo, 2016/02/23 14:28:29]

ASSERT_NOT_REACHED();

(The ArrayBufferOrArrayBufferView type should ensure that we never reach this.)

[harkness, 2016/02/26 11:44:26]

Done.

+    }
+
+    if ((atoi(input) != 0) || (length == 65 && input[0] == 0x04))
+        return WebString::fromUTF8(input, length);
+    return String();

[Peter Beverloo, 2016/02/23 14:28:29]

Per the specification:
Right now we silently fail. Instead, we should throw an InvalidAccessError. You
can do this by rejecting the promise like we do on line 81. (Rejected promises
effectively are thrown exceptions.)

This means that in we might have to separate the concern of (1)
ArrayBufferOrArrayBufferView to WebString, (2) validating that the
`applicationServerKey`, when set, is valid.

[harkness, 2016/02/26 11:44:26]

Done.

+}
+
+WebPushSubscriptionOptions PushManager::toWebPushSubscriptionOptions(const PushSubscriptionOptions& options)
+{
+    WebPushSubscriptionOptions webOptions;
+    webOptions.userVisibleOnly = options.userVisibleOnly();
+    if (options.hasApplicationServerKey()) {

[Peter Beverloo, 2016/02/23 14:28:29]

nit: no need for brackets on one-line statements.

[harkness, 2016/02/26 11:44:26]

Done.

+        webOptions.applicationServerKey = PushManager::toString(options.applicationServerKey());
+    }
+    return webOptions;
+}
+
 ScriptPromise PushManager::subscribe(ScriptState* scriptState, const PushSubscriptionOptions& options)
 {
     if (!m_registration->active())
         return ScriptPromise::rejectWithDOMException(scriptState, DOMException::create(AbortError, "Subscription failed - no active Service Worker"));
 
     ScriptPromiseResolver* resolver = ScriptPromiseResolver::create(scriptState);
     ScriptPromise promise = resolver->promise();
 
     // The document context is the only reasonable context from which to ask the user for permission
     // to use the Push API. The embedder should persist the permission so that later calls in
@@ skipping 33 matching lines @@
     pushProvider()->getPermissionStatus(m_registration->webRegistration(), toWebPushSubscriptionOptions(options), new PushPermissionStatusCallbacks(resolver));
     return promise;
 }
 
 DEFINE_TRACE(PushManager)
 {
     visitor->trace(m_registration);
 }
 
 } // namespace blink