text: //
  // Copyright (C) 2015 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 TPM_MANAGER_SERVER_TPM_CONNECTION_H_
  #define TPM_MANAGER_SERVER_TPM_CONNECTION_H_
  
  #include <string>
  
  #include <base/macros.h>
  #include <trousers/scoped_tss_type.h>
  
  namespace tpm_manager {
  
  class TpmConnection {
   public:
    TpmConnection() = default;
    ~TpmConnection() = default;
  
    // This method returns a handle to the current Tpm context.
    // Note: this method still retains ownership of the context. If this class
    // is deleted, the context handle will be invalidated. Returns 0 on failure.
    TSS_HCONTEXT GetContext();
  
    // This method tries to get a handle to the TPM. Returns 0 on failure.
    TSS_HTPM GetTpm();
  
    // This method tries to get a handle to the TPM and with the given owner
    // password. Returns 0 on failure.
    TSS_HTPM GetTpmWithAuth(const std::string& owner_password);
  
   private:
    // This method connects to the Tpm. Returns true on success.
    bool ConnectContextIfNeeded();
  
    trousers::ScopedTssContext context_;
  
    DISALLOW_COPY_AND_ASSIGN(TpmConnection);
  };
  
  }  // namespace tpm_manager
  
  #endif  // TPM_MANAGER_SERVER_TPM_CONNECTION_H_
  