upload android base code part6

android/system/tpm/trunks/scoped_key_handle.h

@@ -0,0 +1,71 @@
+//
+// Copyright (C) 2014 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+#ifndef TRUNKS_SCOPED_KEY_HANDLE_H_
+#define TRUNKS_SCOPED_KEY_HANDLE_H_
+
+#include "trunks/tpm_generated.h"
+#include "trunks/trunks_export.h"
+#include "trunks/trunks_factory.h"
+
+namespace trunks {
+
+// This class is used to wrap a Key or NV ram handle given by the TPM.
+// It provides a destructor that cleans up TPM resources associated with
+// that handle.
+class TRUNKS_EXPORT ScopedKeyHandle {
+ public:
+  // We provide a factory to the constructor so that we can later free
+  // resources associated with the handle.
+  explicit ScopedKeyHandle(const TrunksFactory& factory);
+  ScopedKeyHandle(const TrunksFactory& factory, TPM_HANDLE handle);
+  virtual ~ScopedKeyHandle();
+
+  // This method releases the TPM_HANDLE associated with this class.
+  // It returns the handle that was previously wrapped, and returns
+  // INVALID_HANDLE if the previous handle was unset.
+  virtual TPM_HANDLE release();
+
+  // This method flushes all context associated with the current handle,
+  // and has the class wrap |new_handle|
+  virtual void reset(TPM_HANDLE new_handle);
+
+  // This method flushes all context associated with the current handle,
+  // and resets the internal handle of the class to the uninitialized value.
+  // Note: After reset() this class should not be used again till a new handle
+  // is injected.
+  virtual void reset();
+
+  // This method returns a pointer to the handle associated with this class.
+  // This method does not transfer ownership.
+  virtual TPM_HANDLE* ptr();
+
+  // This method returns the handle currectly associated with the class.
+  // This method does not transfer ownership, therefore the handle returned
+  // might be stale.
+  virtual TPM_HANDLE get() const;
+
+ private:
+  const TrunksFactory& factory_;
+  TPM_HANDLE handle_;
+  void FlushHandleContext(TPM_HANDLE handle);
+
+  DISALLOW_COPY_AND_ASSIGN(ScopedKeyHandle);
+};
+
+}  // namespace trunks
+
+#endif  // TRUNKS_SCOPED_KEY_HANDLE_H_