/**

 * WinPR: Windows Portable Runtime

 * OpenSSL Library Initialization

 *

 * Copyright 2014 Thincast Technologies GmbH

 * Copyright 2014 Norbert Federa <norbert.federa@thincast.com>

 *

 * 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.

 */

#include <winpr/config.h>

#include <winpr/atexit.h>

#include <winpr/crt.h>

#include <winpr/synch.h>

#include <winpr/ssl.h>

#include <winpr/thread.h>

#include <winpr/crypto.h>

#ifdef WITH_OPENSSL

#include <openssl/ssl.h>

#include <openssl/err.h>

#if defined(OPENSSL_VERSION_MAJOR) && (OPENSSL_VERSION_MAJOR >= 3)

#include <openssl/provider.h>

#endif

#include "../log.h"

#define TAG WINPR_TAG("utils.ssl")

static BOOL g_winpr_openssl_initialized_by_winpr = FALSE;

#if defined(OPENSSL_VERSION_MAJOR) && (OPENSSL_VERSION_MAJOR >= 3)

static OSSL_PROVIDER* s_winpr_openssl_provider_fips = nullptr;

static OSSL_PROVIDER* s_winpr_openssl_provider_legacy = nullptr;

static OSSL_PROVIDER* s_winpr_openssl_provider_default = nullptr;

#endif

/**

 * Note from OpenSSL 1.1.0 "CHANGES":

 * OpenSSL now uses a new threading API. It is no longer necessary to

 * set locking callbacks to use OpenSSL in a multi-threaded environment.

 */

#if (OPENSSL_VERSION_NUMBER < 0x10100000L) || defined(LIBRESSL_VERSION_NUMBER)

#define WINPR_OPENSSL_LOCKING_REQUIRED 1

static int g_winpr_openssl_num_locks = 0;

static HANDLE* g_winpr_openssl_locks = nullptr;

struct CRYPTO_dynlock_value

{

  HANDLE mutex;

};

#if (OPENSSL_VERSION_NUMBER < 0x10000000L) || defined(LIBRESSL_VERSION_NUMBER)

static unsigned long _winpr_openssl_id(void)

{

  return (unsigned long)GetCurrentThreadId();

}

#endif

static void _winpr_openssl_locking(int mode, int type, const char* file, int line)

{

  if (mode & CRYPTO_LOCK)

  {

    (void)WaitForSingleObject(g_winpr_openssl_locks[type], INFINITE);

  }

  else

  {

    (void)ReleaseMutex(g_winpr_openssl_locks[type]);

  }

}

static struct CRYPTO_dynlock_value* _winpr_openssl_dynlock_create(const char* file, int line)

{

  struct CRYPTO_dynlock_value* dynlock;

  if (!(dynlock = (struct CRYPTO_dynlock_value*)malloc(sizeof(struct CRYPTO_dynlock_value))))

    return nullptr;

  if (!(dynlock->mutex = CreateMutex(nullptr, FALSE, nullptr)))

  {

    free(dynlock);

    return nullptr;

  }

  return dynlock;

}

static void _winpr_openssl_dynlock_lock(int mode, struct CRYPTO_dynlock_value* dynlock,

                                        const char* file, int line)

{

  if (mode & CRYPTO_LOCK)

  {

    (void)WaitForSingleObject(dynlock->mutex, INFINITE);

  }

  else

  {

    (void)ReleaseMutex(dynlock->mutex);

  }

}

static void _winpr_openssl_dynlock_destroy(struct CRYPTO_dynlock_value* dynlock, const char* file,

                                           int line)

{

  (void)CloseHandle(dynlock->mutex);

  free(dynlock);

}

static BOOL _winpr_openssl_initialize_locking(void)

{

  int count;

  /* OpenSSL static locking */

  if (CRYPTO_get_locking_callback())

  {

    WLog_WARN(TAG, "OpenSSL static locking callback is already set");

  }

  else

  {

    if ((count = CRYPTO_num_locks()) > 0)

    {

      HANDLE* locks;

      if (!(locks = calloc(count, sizeof(HANDLE))))

      {

        WLog_ERR(TAG, "error allocating lock table");

        return FALSE;

      }

      for (int i = 0; i < count; i++)

      {

        if (!(locks[i] = CreateMutex(nullptr, FALSE, nullptr)))

        {

          WLog_ERR(TAG, "error creating lock #%d", i);

          while (i--)

          {

            if (locks[i])

              (void)CloseHandle(locks[i]);

          }

          free(locks);

          return FALSE;

        }

      }

      g_winpr_openssl_locks = locks;

      g_winpr_openssl_num_locks = count;

      CRYPTO_set_locking_callback(_winpr_openssl_locking);

    }

  }

  /* OpenSSL dynamic locking */

  if (CRYPTO_get_dynlock_create_callback() || CRYPTO_get_dynlock_lock_callback() ||

      CRYPTO_get_dynlock_destroy_callback())

  {

    WLog_WARN(TAG, "dynamic locking callbacks are already set");

  }

  else

  {

    CRYPTO_set_dynlock_create_callback(_winpr_openssl_dynlock_create);

    CRYPTO_set_dynlock_lock_callback(_winpr_openssl_dynlock_lock);

    CRYPTO_set_dynlock_destroy_callback(_winpr_openssl_dynlock_destroy);

  }

  /* Use the deprecated CRYPTO_get_id_callback() if building against OpenSSL < 1.0.0 */

#if (OPENSSL_VERSION_NUMBER < 0x10000000L) || defined(LIBRESSL_VERSION_NUMBER)

  if (CRYPTO_get_id_callback())

  {

    WLog_WARN(TAG, "OpenSSL id_callback is already set");

  }

  else

  {

    CRYPTO_set_id_callback(_winpr_openssl_id);

  }

#endif

  return TRUE;

}

static BOOL _winpr_openssl_cleanup_locking(void)

{

  /* undo our static locking modifications */

  if (CRYPTO_get_locking_callback() == _winpr_openssl_locking)

  {

    CRYPTO_set_locking_callback(nullptr);

    for (int i = 0; i < g_winpr_openssl_num_locks; i++)

    {

      (void)CloseHandle(g_winpr_openssl_locks[i]);

    }

    g_winpr_openssl_num_locks = 0;

    free(g_winpr_openssl_locks);

    g_winpr_openssl_locks = nullptr;

  }

  /* unset our dynamic locking callbacks */

  if (CRYPTO_get_dynlock_create_callback() == _winpr_openssl_dynlock_create)

  {

    CRYPTO_set_dynlock_create_callback(nullptr);

  }

  if (CRYPTO_get_dynlock_lock_callback() == _winpr_openssl_dynlock_lock)

  {

    CRYPTO_set_dynlock_lock_callback(nullptr);

  }

  if (CRYPTO_get_dynlock_destroy_callback() == _winpr_openssl_dynlock_destroy)

  {

    CRYPTO_set_dynlock_destroy_callback(nullptr);

  }

#if (OPENSSL_VERSION_NUMBER < 0x10000000L) || defined(LIBRESSL_VERSION_NUMBER)

  if (CRYPTO_get_id_callback() == _winpr_openssl_id)

  {

    CRYPTO_set_id_callback(nullptr);

  }

#endif

  return TRUE;

}

#endif /* OpenSSL < 1.1.0 */

static BOOL winpr_enable_fips(DWORD flags)

{

  if (flags & WINPR_SSL_INIT_ENABLE_FIPS)

  {

#if (OPENSSL_VERSION_NUMBER < 0x10001000L) || defined(LIBRESSL_VERSION_NUMBER)

    WLog_ERR(TAG, "Openssl fips mode not available on openssl versions less than 1.0.1!");

    return FALSE;

#else

    WLog_DBG(TAG, "Ensuring openssl fips mode is enabled");

#if defined(OPENSSL_VERSION_MAJOR) && (OPENSSL_VERSION_MAJOR >= 3)

    s_winpr_openssl_provider_fips = OSSL_PROVIDER_load(nullptr, "fips");

    if (s_winpr_openssl_provider_fips == nullptr)

    {

      WLog_WARN(TAG, "OpenSSL FIPS provider failed to load");

    }

    if (!EVP_default_properties_is_fips_enabled(nullptr))

#else

    if (FIPS_mode() != 1)

#endif

    {

#if defined(OPENSSL_VERSION_MAJOR) && (OPENSSL_VERSION_MAJOR >= 3)

      if (EVP_set_default_properties(nullptr, "fips=yes"))

#else

      if (FIPS_mode_set(1))

#endif

        WLog_INFO(TAG, "Openssl fips mode enabled!");

      else

      {

        WLog_ERR(TAG, "Openssl fips mode enable failed!");

        return FALSE;

      }

    }

#endif

  }

  return TRUE;

}

static void winpr_openssl_cleanup(void)

{

  winpr_CleanupSSL(WINPR_SSL_INIT_DEFAULT);

}

static BOOL CALLBACK winpr_openssl_initialize(WINPR_ATTR_UNUSED PINIT_ONCE once, PVOID param,

                                              WINPR_ATTR_UNUSED PVOID* context)

{

  DWORD flags = param ? *(PDWORD)param : WINPR_SSL_INIT_DEFAULT;

  if (flags & WINPR_SSL_INIT_ALREADY_INITIALIZED)

  {

    return TRUE;

  }

#ifdef WINPR_OPENSSL_LOCKING_REQUIRED

  if (flags & WINPR_SSL_INIT_ENABLE_LOCKING)

  {

    if (!_winpr_openssl_initialize_locking())

    {

      return FALSE;

    }

  }

#endif

  /* SSL_load_error_strings() is void */

#if (OPENSSL_VERSION_NUMBER < 0x10100000L) || defined(LIBRESSL_VERSION_NUMBER)

  SSL_load_error_strings();

  /* SSL_library_init() always returns "1" */

  SSL_library_init();

  OpenSSL_add_all_digests();

  OpenSSL_add_all_ciphers();

#else

  if (OPENSSL_init_ssl(OPENSSL_INIT_LOAD_SSL_STRINGS | OPENSSL_INIT_LOAD_CRYPTO_STRINGS |

                           OPENSSL_INIT_ADD_ALL_CIPHERS | OPENSSL_INIT_ADD_ALL_DIGESTS |

                           OPENSSL_INIT_ENGINE_ALL_BUILTIN,

                       nullptr) != 1)

    return FALSE;

#endif

#if defined(OPENSSL_VERSION_MAJOR) && (OPENSSL_VERSION_MAJOR >= 3)

  /* The legacy provider is needed for MD4. */

  s_winpr_openssl_provider_legacy = OSSL_PROVIDER_load(nullptr, "legacy");

  if (s_winpr_openssl_provider_legacy == nullptr)

  {

    WLog_WARN(TAG, "OpenSSL LEGACY provider failed to load, no md4 support available!");

  }

  s_winpr_openssl_provider_default = OSSL_PROVIDER_load(nullptr, "default");

  if (s_winpr_openssl_provider_default == nullptr)

  {

    WLog_WARN(TAG, "OpenSSL DEFAULT provider failed to load");

  }

#endif

  (void)winpr_atexit(winpr_openssl_cleanup);

  g_winpr_openssl_initialized_by_winpr = TRUE;

  return TRUE;

}

/* exported functions */

BOOL winpr_InitializeSSL(DWORD flags)

{

  static INIT_ONCE once = INIT_ONCE_STATIC_INIT;

  if (!InitOnceExecuteOnce(&once, winpr_openssl_initialize, &flags, nullptr))

    return FALSE;

  return winpr_enable_fips(flags);

}

#if defined(OPENSSL_VERSION_MAJOR) && (OPENSSL_VERSION_MAJOR >= 3)

static int unload(OSSL_PROVIDER* provider, WINPR_ATTR_UNUSED void* data)

{

  if (!provider)

    return 1;

  const char* name = OSSL_PROVIDER_get0_name(provider);

  if (!name)

    return 1;

  OSSL_LIB_CTX* ctx = OSSL_LIB_CTX_get0_global_default();

  const int rc = OSSL_PROVIDER_available(ctx, name);

  if (rc < 1)

    return 1;

  OSSL_PROVIDER_unload(provider);

  return 1;

}

#endif

BOOL winpr_CleanupSSL(DWORD flags)

{

  if (flags & WINPR_SSL_CLEANUP_GLOBAL)

  {

    if (!g_winpr_openssl_initialized_by_winpr)

    {

      WLog_WARN(TAG, "ssl was not initialized by winpr");

      return FALSE;

    }

    g_winpr_openssl_initialized_by_winpr = FALSE;

#ifdef WINPR_OPENSSL_LOCKING_REQUIRED

    _winpr_openssl_cleanup_locking();

#endif

#if (OPENSSL_VERSION_NUMBER < 0x10100000L) || defined(LIBRESSL_VERSION_NUMBER)

    CRYPTO_cleanup_all_ex_data();

    ERR_free_strings();

    EVP_cleanup();

#endif

#ifdef WINPR_OPENSSL_LOCKING_REQUIRED

    flags |= WINPR_SSL_CLEANUP_THREAD;

#endif

  }

#ifdef WINPR_OPENSSL_LOCKING_REQUIRED

  if (flags & WINPR_SSL_CLEANUP_THREAD)

  {

#if (OPENSSL_VERSION_NUMBER < 0x10000000L) || defined(LIBRESSL_VERSION_NUMBER)

    ERR_remove_state(0);

#else

    ERR_remove_thread_state(nullptr);

#endif

  }

#endif

#if defined(OPENSSL_VERSION_MAJOR) && (OPENSSL_VERSION_MAJOR >= 3)

  OSSL_LIB_CTX* ctx = OSSL_LIB_CTX_get0_global_default();

  if (ctx)

    OSSL_PROVIDER_do_all(ctx, unload, nullptr);

#endif

  return TRUE;

}

BOOL winpr_FIPSMode(void)

{

#if (OPENSSL_VERSION_NUMBER < 0x10001000L) || defined(LIBRESSL_VERSION_NUMBER)

  return FALSE;

#elif defined(OPENSSL_VERSION_MAJOR) && (OPENSSL_VERSION_MAJOR >= 3)

  return (EVP_default_properties_is_fips_enabled(nullptr) == 1);

#else

  return (FIPS_mode() == 1);

#endif

}

#else

BOOL winpr_InitializeSSL(DWORD flags)

{

  return TRUE;

}

BOOL winpr_CleanupSSL(DWORD flags)

{

  return TRUE;

}

BOOL winpr_FIPSMode(void)

{

  return FALSE;

}

#endif