/* ====================================================================
 * Copyright (c) 1998-2001 The OpenSSL Project.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer. 
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. All advertising materials mentioning features or use of this
 *    software must display the following acknowledgment:
 *    "This product includes software developed by the OpenSSL Project
 *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
 *
 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
 *    endorse or promote products derived from this software without
 *    prior written permission. For written permission, please contact
 *    openssl-core@openssl.org.
 *
 * 5. Products derived from this software may not be called "OpenSSL"
 *    nor may "OpenSSL" appear in their names without prior written
 *    permission of the OpenSSL Project.
 *
 * 6. Redistributions of any form whatsoever must retain the following
 *    acknowledgment:
 *    "This product includes software developed by the OpenSSL Project
 *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
 *
 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 * ====================================================================
 *
 * This product includes cryptographic software written by Eric Young
 * (eay@cryptsoft.com).  This product includes software written by Tim
 * Hudson (tjh@cryptsoft.com). */

#ifndef OPENSSL_HEADER_BASE_H
#define OPENSSL_HEADER_BASE_H

/* Needed for BORINGSSL_MAKE_DELETER */
# include <openssl/bio.h>
# include <openssl/evp.h>
# include <openssl/dh.h>
# include <openssl/x509.h>
# include <openssl/ssl.h>

# define OPENSSL_ARRAY_SIZE(array) (sizeof(array) / sizeof((array)[0]))

/* Temporary TLS1.3 defines until OpenSSL supports these */
# define TLS1_3_VERSION                  0x0304
# define SSL_OP_NO_TLSv1_3               0

extern "C++" {

#include <memory>

namespace bssl {

namespace internal {

template <typename T>
struct DeleterImpl {};

template <typename T>
struct Deleter {
  void operator()(T *ptr) {
    // Rather than specialize Deleter for each type, we specialize
    // DeleterImpl. This allows bssl::UniquePtr<T> to be used while only
    // including base.h as long as the destructor is not emitted. This matches
    // std::unique_ptr's behavior on forward-declared types.
    //
    // DeleterImpl itself is specialized in the corresponding module's header
    // and must be included to release an object. If not included, the compiler
    // will error that DeleterImpl<T> does not have a method Free.
    DeleterImpl<T>::Free(ptr);
  }
};

template <typename T, typename CleanupRet, void (*init)(T *),
          CleanupRet (*cleanup)(T *)>
class StackAllocated {
 public:
  StackAllocated() { init(&ctx_); }
  ~StackAllocated() { cleanup(&ctx_); }

  StackAllocated(const StackAllocated<T, CleanupRet, init, cleanup> &) = delete;
  T& operator=(const StackAllocated<T, CleanupRet, init, cleanup> &) = delete;

  T *get() { return &ctx_; }
  const T *get() const { return &ctx_; }

  void Reset() {
    cleanup(&ctx_);
    init(&ctx_);
  }

 private:
  T ctx_;
};

}  // namespace internal

#define BORINGSSL_MAKE_DELETER(type, deleter)     \
  namespace internal {                            \
  template <>                                     \
  struct DeleterImpl<type> {                      \
    static void Free(type *ptr) { deleter(ptr); } \
  };                                              \
  }

// This makes a unique_ptr to STACK_OF(type) that owns all elements on the
// stack, i.e. it uses sk_pop_free() to clean up.
#define BORINGSSL_MAKE_STACK_DELETER(type, deleter) \
  namespace internal {                              \
  template <>                                       \
  struct DeleterImpl<STACK_OF(type)> {              \
    static void Free(STACK_OF(type) *ptr) {         \
      sk_##type##_pop_free(ptr, deleter);           \
    }                                               \
  };                                                \
  }

// Holds ownership of heap-allocated BoringSSL structures. Sample usage:
//   bssl::UniquePtr<BIO> rsa(RSA_new());
//   bssl::UniquePtr<BIO> bio(BIO_new(BIO_s_mem()));
template <typename T>
using UniquePtr = std::unique_ptr<T, internal::Deleter<T>>;

BORINGSSL_MAKE_DELETER(BIO, BIO_free)
BORINGSSL_MAKE_DELETER(EVP_PKEY, EVP_PKEY_free)
BORINGSSL_MAKE_DELETER(DH, DH_free)
BORINGSSL_MAKE_DELETER(X509, X509_free)
BORINGSSL_MAKE_DELETER(SSL, SSL_free)
BORINGSSL_MAKE_DELETER(SSL_CTX, SSL_CTX_free)
BORINGSSL_MAKE_DELETER(SSL_SESSION, SSL_SESSION_free)

}  // namespace bssl

}  /* extern C++ */


#endif  /* OPENSSL_HEADER_BASE_H */
