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#ifndef __GRPCPP_CREDENTIALS_H_
#define __GRPCPP_CREDENTIALS_H_

#include <memory>

#include <grpc++/config.h>

struct grpc_credentials;

namespace grpc {

// grpc_credentials wrapper class. Typical use in C++ applications is limited
// to creating an instance using CredentialsFactory, and passing it down
// during channel construction.

class Credentials final {
 public:
  ~Credentials();
  // TODO(abhikumar): Specify a plugin API here to be implemented by
  // credentials that do not have a corresponding implementation in C.

 protected:
  explicit Credentials(grpc_credentials*);

 private:
  grpc_credentials* GetRawCreds();

  friend class CredentialsFactory;

  grpc_credentials* creds_;
};

// Options used to build SslCredentials
struct SslCredentialsOptions {
  grpc::string pem_root_certs;
  grpc::string pem_private_key;
  grpc::string pem_cert_chain;
};

// Factory for building different types of Credentials
class CredentialsFactory {
 public:
  // Builds credentials with reasonable defaults.
  static std::unique_ptr<Credentials> DefaultCredentials();

  // Builds SSL Credentials given SSL specific options
  static std::unique_ptr<Credentials> SslCredentials(
      const SslCredentialsOptions& options);

  // Builds credentials for use when running in GCE
  static std::unique_ptr<Credentials> ComputeEngineCredentials();


  // Combines two credentials objects into a composite credentials
  static std::unique_ptr<Credentials> ComposeCredentials(
      const std::unique_ptr<Credentials>& creds1,
      const std::unique_ptr<Credentials>& creds2);
};

}  // namespace grpc

#endif  // __GRPCPP_CREDENTIALS_H_