ssl.c

 
#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
 
#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