#ifndef __DIFFIEHELLMAN__
#define __DIFFIEHELLMAN__

/*=========================================================================
 * Copyright (c) 2002-2014 Pivotal Software, Inc. All Rights Reserved.
 * This product is protected by U.S. and international copyright
 * and intellectual property laws. Pivotal products are covered by
 * more patents listed at http://www.pivotal.io/patents.
 *========================================================================
 */
#include <ace/DLL.h>
#include <ace/OS.h>
#include <string>
#include "../CacheableBuiltins.hpp"
#include "../Properties.hpp"
#include <ace/Recursive_Thread_Mutex.h>

#define DH_ERR_NO_ERROR         0
#define DH_ERR_UNSUPPORTED_ALGO 1
#define DH_ERR_ILLEGAL_KEYSIZE  2
#define DH_ERR_SUBJECT_NOT_FOUND 3
#define DH_ERR_NO_CERTIFICATES  4
#define DH_ERR_INVALID_SIGN     5

const char SecurityClientDhAlgo[] = "security-client-dhalgo";
const char SecurityClientKsPath[] = "security-client-kspath";

namespace gemfire {

class DiffieHellman {
  static ACE_Recursive_Thread_Mutex s_mutex;
public:
  void initDhKeys(const PropertiesPtr & props);
  void clearDhKeys(void);
  CacheableBytesPtr getPublicKey(void);
  void setPublicKeyOther(const CacheableBytesPtr & pubkey);
  void computeSharedSecret(void);
  CacheableBytesPtr encrypt(const CacheableBytesPtr & cleartext);
  CacheableBytesPtr encrypt(const uint8_t * cleartext, int len);
  CacheableBytesPtr decrypt(const CacheableBytesPtr & cleartext);
  CacheableBytesPtr decrypt(const uint8_t * cleartext, int len);
  bool verify(const CacheableStringPtr & subject, const CacheableBytesPtr & challenge, const CacheableBytesPtr & response);

  static void initOpenSSLFuncPtrs();

  DiffieHellman() : 
       /* adongre
        * CID 28933: Uninitialized pointer field (UNINIT_CTOR)
        */
       m_dhCtx((void*)0)
  {
    
  }
private:

  void * m_dhCtx;
  static bool m_inited;
  static void* getOpenSSLFuncPtr(const char* function_name);

  // OpenSSL Func Ptrs: Declare Func Ptr type and a static variable of FuncPtr type.
  //Convention: <Orig Func Name>_Type and <Orig Func Name>_Ptr
  typedef int (*gf_initDhKeys_Type)(void ** dhCtx, const char* dhAlgo, const char* ksPath);
  typedef void (*gf_clearDhKeys_Type)(void * dhCtx);
  typedef unsigned char* (*gf_getPublicKey_Type)(void * dhCtx, int* len);
  typedef void (*gf_setPublicKeyOther_Type)(void * dhCtx, const unsigned char* pubkey, int length);
  typedef void (*gf_computeSharedSecret_Type)(void * dhCtx);
  typedef unsigned char* (*gf_encryptDH_Type)(void * dhCtx, const unsigned char* cleartext,
    int len, int* retLen);
  typedef unsigned char* (*gf_decryptDH_Type)(void * dhCtx, const unsigned char* cleartext,
    int len, int* retLen);
  typedef bool (*gf_verifyDH_Type)(void * dhCtx, const char* subject, const unsigned char* challenge,
    int challengeLen, const unsigned char* response, int responseLen, int*reason);
  
#define DECLARE_DH_FUNC_PTR(OrigName)   \
  static OrigName##_Type OrigName##_Ptr;

  DECLARE_DH_FUNC_PTR(gf_initDhKeys)
  DECLARE_DH_FUNC_PTR(gf_clearDhKeys)
  DECLARE_DH_FUNC_PTR(gf_getPublicKey)
  DECLARE_DH_FUNC_PTR(gf_setPublicKeyOther)
  DECLARE_DH_FUNC_PTR(gf_computeSharedSecret)
  DECLARE_DH_FUNC_PTR(gf_encryptDH)
  DECLARE_DH_FUNC_PTR(gf_decryptDH)
  DECLARE_DH_FUNC_PTR(gf_verifyDH)

  static ACE_DLL m_dll;

}; // class DiffieHellman

}; // namespace gemfire

#endif // __DIFFIEHELLMAN__