Cast: Adding helper crypto classes

media/cast/transport/utility/transport_encryption_handler.h

+// 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.
+
+#ifndef MEDIA_CAST_TRANSPORT_TRANSPORT_UTILITY_ENCRYPTION_HANDLER_H_
+#define MEDIA_CAST_TRANSPORT_TRANSPORT_UTILITY_ENCRYPTION_HANDLER_H_
+
+// Helper class to handle encryption for the Cast Transport library.
+#include <string>
+
+#include "base/basictypes.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/strings/string_piece.h"
+#include "base/threading/non_thread_safe.h"
+
+namespace crypto {
+class Encryptor;
+class SymmetricKey;
+}
+
+namespace media {
+namespace cast {
+namespace transport {
+
+class TransportEncryptionHandler : public base::NonThreadSafe {
+ public:
+  TransportEncryptionHandler();
+  ~TransportEncryptionHandler();
+
+  bool Initialize(std::string aes_key, std::string aes_iv_mask);
+
+  bool Encrypt(uint32 frame_id, std::string data, std::string* encrypted_data);
+
+  bool Decrypt(uint32 frame_id,
+               const base::StringPiece& ciphertext,
+               std::string* plaintext);
+
+  bool initialized() const { return initialized_; }
+
+ private:
+  scoped_ptr<crypto::SymmetricKey> key_;
+  scoped_ptr<crypto::Encryptor> encryptor_;
+  std::string iv_mask_;
+  bool initialized_;
+
+  DISALLOW_COPY_AND_ASSIGN(TransportEncryptionHandler);
+};
+
+}  // namespace transport
+}  // namespace cast
+}  // namespace media
+
+#endif  // MEDIA_CAST_TRANSPORT_TRANSPORT_UTILITY_ENCRYPTION_HANDLER_H_