Hook up the Push API with GCM's new ability to own encryption keys.

components/gcm_driver/crypto/gcm_encryption_provider.h

+// Copyright 2015 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.
+
+#ifndef COMPONENTS_GCM_DRIVER_CRYPTO_GCM_ENCRYPTION_PROVIDER_H_
+#define COMPONENTS_GCM_DRIVER_CRYPTO_GCM_ENCRYPTION_PROVIDER_H_
+
+#include <stdint.h>
+#include <string>
+
+#include "base/callback_forward.h"
+#include "base/macros.h"
+#include "base/memory/ref_counted.h"
+#include "base/memory/weak_ptr.h"
+
+namespace base {
+class FilePath;
+class SequencedTaskRunner;
+}
+
+namespace gcm {
+
+class GCMKeyStore;
+class KeyPair;
+
+// Provider that enables the GCM Driver to deal with encryption key management
+// and decryption of incoming messages.
+class GCMEncryptionProvider {
+ public:
+  // Callback to be invoked when the public encryption key is available.
+  using PublicKeyCallback = base::Callback<void(const std::string&)>;
+
+  GCMEncryptionProvider();
+  ~GCMEncryptionProvider();
+
+  // Initializes the encryption provider with the |store_path| and the
+  // |blocking_task_runner|. Done separately from the constructor in order to
+  // avoid needing a blocking task runner for anything using GCMDriver.
+  void Init(
+      const base::FilePath& store_path,
+      const scoped_refptr<base::SequencedTaskRunner>& blocking_task_runner);
+
+  // Retrieves the public encryption key belonging to |app_id|. If no keys have
+  // been associated with |app_id| yet, they will be created.
+  void GetPublicKey(const std::string& app_id,
+                    const PublicKeyCallback& callback);
+
+ private:
+  void DidGetPublicKey(const std::string& app_id,
+                       const PublicKeyCallback& callback,
+                       const KeyPair& pair);
+
+  void DidCreatePublicKey(const PublicKeyCallback& callback,
+                          const KeyPair& pair);
+
+  scoped_refptr<GCMKeyStore> key_store_;
+
+  base::WeakPtrFactory<GCMEncryptionProvider> weak_ptr_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(GCMEncryptionProvider);
+};
+
+}  // namespace gcm
+
+#endif  // COMPONENTS_GCM_DRIVER_CRYPTO_GCM_ENCRYPTION_PROVIDER_H_