/*

 * Copyright (C) 2001-2016 Free Software Foundation, Inc.

 * Copyright (C) 2015-2016 Red Hat, Inc.

 *

 * Author: Nikos Mavrogiannopoulos

 *

 * This file is part of GnuTLS.

 *

 * The GnuTLS is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Lesser General Public License

 * as published by the Free Software Foundation; either version 2.1 of

 * the License, or (at your option) any later version.

 *

 * This library is distributed in the hope that it will be useful, but

 * WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

 * Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public License

 * along with this program.  If not, see <https://www.gnu.org/licenses/>.

 *

 */

#include "gnutls_int.h"

#include "errors.h"

#include <libtasn1.h>

#include "dh.h"

#include "random.h"

#include <gnutls/pkcs11.h>

#include "hello_ext.h" /* for _gnutls_hello_ext_init */

#include "supplemental.h" /* for _gnutls_supplemental_deinit */

#include "locks.h"

#include "system.h"

#include "accelerated/cryptodev.h"

#include "accelerated/afalg.h"

#include "accelerated/accelerated.h"

#include "fips.h"

#include "atfork.h"

#include "system-keys.h"

#include "str.h"

#include "global.h"

/* Minimum library versions we accept. */

#define GNUTLS_MIN_LIBTASN1_VERSION "0.3.4"

#ifdef __sun

#pragma fini(lib_deinit)

#pragma init(lib_init)

#define _CONSTRUCTOR

#define _DESTRUCTOR

#else

#define _CONSTRUCTOR __attribute__((constructor))

#define _DESTRUCTOR __attribute__((destructor))

#endif

#ifndef _WIN32

int __attribute__((weak)) _gnutls_global_init_skip(void);

int _gnutls_global_init_skip(void)

{

  return 0;

}

#else

inline static int _gnutls_global_init_skip(void)

{

  return 0;

}

#endif

/* created by asn1c */

extern const asn1_static_node gnutls_asn1_tab[];

extern const asn1_static_node pkix_asn1_tab[];

asn1_node _gnutls_pkix1_asn = NULL;

asn1_node _gnutls_gnutls_asn = NULL;

gnutls_log_func _gnutls_log_func = NULL;

gnutls_audit_log_func _gnutls_audit_log_func = NULL;

int _gnutls_log_level = 0; /* default log level */

unsigned int _gnutls_global_version = GNUTLS_VERSION_NUMBER;

static int _gnutls_global_init(unsigned constructor);

static void _gnutls_global_deinit(unsigned destructor);

static void default_log_func(int level, const char *str)

{

  fprintf(stderr, "gnutls[%d]: %s", level, str);

}

/**

 * gnutls_global_set_log_function:

 * @log_func: it's a log function

 *

 * This is the function where you set the logging function gnutls is

 * going to use.  This function only accepts a character array.

 * Normally you may not use this function since it is only used for

 * debugging purposes.

 *

 * @gnutls_log_func is of the form,

 * void (*gnutls_log_func)( int level, const char*);

 **/

void gnutls_global_set_log_function(gnutls_log_func log_func)

{

  _gnutls_log_func = log_func;

}

/**

 * gnutls_global_set_audit_log_function:

 * @log_func: it is the audit log function

 *

 * This is the function to set the audit logging function. This

 * is a function to report important issues, such as possible

 * attacks in the protocol. This is different from gnutls_global_set_log_function()

 * because it will report also session-specific events. The session

 * parameter will be null if there is no corresponding TLS session.

 *

 * @gnutls_audit_log_func is of the form,

 * void (*gnutls_audit_log_func)( gnutls_session_t, const char*);

 *

 * Since: 3.0

 **/

void gnutls_global_set_audit_log_function(gnutls_audit_log_func log_func)

{

  _gnutls_audit_log_func = log_func;

}

static void gettime_from_time(struct timespec *t)

{

  t->tv_sec = gnutls_time(NULL);

  t->tv_nsec = 0;

}

/**

 * gnutls_global_set_time_function:

 * @time_func: it's the system time function, a gnutls_time_func() callback.

 *

 * This is the function where you can override the default system time

 * function.  The application provided function should behave the same

 * as the standard function.

 *

 * Since: 2.12.0

 **/

void gnutls_global_set_time_function(gnutls_time_func time_func)

{

  gnutls_time = time_func;

  /* When the time function is overridden, also override the

   * gettime function to use the derived value, even if its

   * resolution is lower.

   */

  _gnutls_global_set_gettime_function(gettime_from_time);

}

/**

 * gnutls_global_set_log_level:

 * @level: it's an integer from 0 to 99.

 *

 * This is the function that allows you to set the log level.  The

 * level is an integer between 0 and 9.  Higher values mean more

 * verbosity. The default value is 0.  Larger values should only be

 * used with care, since they may reveal sensitive information.

 *

 * Use a log level over 10 to enable all debugging options.

 **/

void gnutls_global_set_log_level(int level)

{

  _gnutls_log_level = level;

}

/**

 * gnutls_global_set_mem_functions:

 * @alloc_func: it's the default memory allocation function. Like malloc().

 * @secure_alloc_func: This is the memory allocation function that will be used for sensitive data.

 * @is_secure_func: a function that returns 0 if the memory given is not secure. May be NULL.

 * @realloc_func: A realloc function

 * @free_func: The function that frees allocated data. Must accept a NULL pointer.

 *

 * Deprecated: since 3.3.0 it is no longer possible to replace the internally used 

 *  memory allocation functions

 *

 * This is the function where you set the memory allocation functions

 * gnutls is going to use. By default the libc's allocation functions

 * (malloc(), free()), are used by gnutls, to allocate both sensitive

 * and not sensitive data.  This function is provided to set the

 * memory allocation functions to something other than the defaults

 *

 * This function must be called before gnutls_global_init() is called.

 * This function is not thread safe.

 **/

void gnutls_global_set_mem_functions(gnutls_alloc_function alloc_func,

             gnutls_alloc_function secure_alloc_func,

             gnutls_is_secure_function is_secure_func,

             gnutls_realloc_function realloc_func,

             gnutls_free_function free_func)

{

  _gnutls_debug_log(

    "called the deprecated gnutls_global_set_mem_functions()\n");

}

GNUTLS_STATIC_MUTEX(global_init_mutex);

static int _gnutls_init = 0;

/* cache the return code */

static int _gnutls_init_ret = 0;

/**

 * gnutls_global_init:

 *

 * Since GnuTLS 3.3.0 this function is no longer necessary to be explicitly

 * called. To disable the implicit call (in a library constructor) of this

 * function set the environment variable %GNUTLS_NO_IMPLICIT_INIT to 1.

 *

 * This function performs any required precalculations, detects

 * the supported CPU capabilities and initializes the underlying

 * cryptographic backend. In order to free any resources 

 * taken by this call you should gnutls_global_deinit() 

 * when gnutls usage is no longer needed.

 *

 * This function increments a global counter, so that

 * gnutls_global_deinit() only releases resources when it has been

 * called as many times as gnutls_global_init().  This is useful when

 * GnuTLS is used by more than one library in an application.  This

 * function can be called many times, but will only do something the

 * first time. It is thread safe since GnuTLS 3.3.0.

 *

 * A subsequent call of this function if the initial has failed will

 * return the same error code.

 *

 * Returns: On success, %GNUTLS_E_SUCCESS (0) is returned,

 *   otherwise a negative error code is returned.

 **/

int gnutls_global_init(void)

{

  return _gnutls_global_init(0);

}

static int _gnutls_global_init(unsigned constructor)

{

  int ret = 0, res;

  int level;

  const char *e;

  if (!constructor) {

    ret = gnutls_static_mutex_lock(&global_init_mutex);

    if (ret < 0) {

      return gnutls_assert_val(ret);

    }

  }

  _gnutls_init++;

  if (_gnutls_init > 1) {

    ret = _gnutls_init_ret;

    goto out;

  }

  _gnutls_switch_lib_state(LIB_STATE_INIT);

  e = secure_getenv("GNUTLS_DEBUG_LEVEL");

  if (e != NULL) {

    level = atoi(e);

    gnutls_global_set_log_level(level);

    if (_gnutls_log_func == NULL)

      gnutls_global_set_log_function(default_log_func);

    _gnutls_debug_log("Enabled GnuTLS " VERSION " logging...\n");

  }

#ifdef HAVE_DCGETTEXT

  bindtextdomain(PACKAGE, LOCALEDIR);

#endif

  res = gnutls_crypto_init();

  if (res != 0) {

    gnutls_assert();

    ret = GNUTLS_E_CRYPTO_INIT_FAILED;

    goto out;

  }

  ret = _gnutls_system_key_init();

  if (ret != 0) {

    gnutls_assert();

  }

  /* initialize ASN.1 parser

   */

  if (asn1_check_version(GNUTLS_MIN_LIBTASN1_VERSION) == NULL) {

    gnutls_assert();

    _gnutls_debug_log("Checking for libtasn1 failed: %s < %s\n",

          asn1_check_version(NULL),

          GNUTLS_MIN_LIBTASN1_VERSION);

    ret = GNUTLS_E_INCOMPATIBLE_LIBTASN1_LIBRARY;

    goto out;

  }

  _gnutls_pkix1_asn = NULL;

  res = asn1_array2tree(pkix_asn1_tab, &_gnutls_pkix1_asn, NULL);

  if (res != ASN1_SUCCESS) {

    gnutls_assert();

    ret = _gnutls_asn2err(res);

    goto out;

  }

  res = asn1_array2tree(gnutls_asn1_tab, &_gnutls_gnutls_asn, NULL);

  if (res != ASN1_SUCCESS) {

    gnutls_assert();

    ret = _gnutls_asn2err(res);

    goto out;

  }

  /* Initialize the random generator */

  ret = _gnutls_rnd_preinit();

  if (ret < 0) {

    gnutls_assert();

    goto out;

  }

  /* Initialize the default TLS extensions */

  ret = _gnutls_hello_ext_init();

  if (ret < 0) {

    gnutls_assert();

    goto out;

  }

  ret = gnutls_system_global_init();

  if (ret < 0) {

    gnutls_assert();

    goto out;

  }

#ifndef _WIN32

  ret = _gnutls_register_fork_handler();

  if (ret < 0) {

    gnutls_assert();

    goto out;

  }

#endif

#ifdef ENABLE_FIPS140

  res = _gnutls_fips_mode_enabled();

  /* res == 1 -> fips140-2 mode enabled

   * res == 2 -> only self checks performed - but no failure

   * res == not in fips140 mode

   */

  if (res != 0) {

    _gnutls_debug_log("FIPS140-2 mode: %d\n", res);

    _gnutls_priority_update_fips();

    /* first round of self checks, these are done on the

     * nettle algorithms which are used internally */

    _gnutls_switch_lib_state(LIB_STATE_SELFTEST);

    ret = _gnutls_fips_perform_self_checks1();

    if (ret < 0) {

      _gnutls_switch_lib_state(LIB_STATE_ERROR);

      _gnutls_audit_log(

        NULL, "FIPS140-2 self testing part1 failed\n");

      if (res != 2) {

        gnutls_assert();

        goto out;

      }

    }

  }

#endif

  _gnutls_register_accel_crypto();

  _gnutls_cryptodev_init();

  _gnutls_afalg_init();

#ifdef ENABLE_FIPS140

  /* These self tests are performed on the overridden algorithms

   * (e.g., AESNI overridden AES). They are after _gnutls_register_accel_crypto()

   * intentionally */

  if (res != 0) {

    _gnutls_switch_lib_state(LIB_STATE_SELFTEST);

    ret = _gnutls_fips_perform_self_checks2();

    if (ret < 0) {

      _gnutls_switch_lib_state(LIB_STATE_ERROR);

      _gnutls_audit_log(

        NULL, "FIPS140-2 self testing part 2 failed\n");

      if (res != 2) {

        gnutls_assert();

        goto out;

      }

    }

    _gnutls_fips_mode_reset_zombie();

  }

#endif

  _gnutls_prepare_to_load_system_priorities();

  _gnutls_switch_lib_state(LIB_STATE_OPERATIONAL);

  ret = 0;

out:

  _gnutls_init_ret = ret;

  if (!constructor) {

    (void)gnutls_static_mutex_unlock(&global_init_mutex);

  }

  return ret;

}

static void _gnutls_global_deinit(unsigned destructor)

{

  if (!destructor) {

    if (gnutls_static_mutex_lock(&global_init_mutex) < 0) {

      return;

    }

  }

  if (_gnutls_init == 1) {

    _gnutls_init = 0;

    if (_gnutls_init_ret < 0) {

      /* only deinitialize if gnutls_global_init() has

       * succeeded */

      gnutls_assert();

      goto fail;

    }

    _gnutls_system_key_deinit();

    gnutls_crypto_deinit();

    _gnutls_rnd_deinit();

    _gnutls_hello_ext_deinit();

    asn1_delete_structure(&_gnutls_gnutls_asn);

    asn1_delete_structure(&_gnutls_pkix1_asn);

    _gnutls_crypto_deregister();

    gnutls_system_global_deinit();

    _gnutls_cryptodev_deinit();

    _gnutls_supplemental_deinit();

    _gnutls_unload_system_priorities();

#ifdef ENABLE_PKCS11

    /* Do not try to deinitialize the PKCS #11 libraries

     * from the destructor. If we do and the PKCS #11 modules

     * are already being unloaded, we may crash.

     */

    if (destructor == 0) {

      gnutls_pkcs11_deinit();

    }

#endif

#ifdef HAVE_TROUSERS

    _gnutls_tpm_global_deinit();

#endif

#ifdef HAVE_TPM2

    _gnutls_tpm2_deinit();

#endif

    _gnutls_nss_keylog_deinit();

  } else {

    if (_gnutls_init > 0)

      _gnutls_init--;

  }

fail:

  if (!destructor) {

    (void)gnutls_static_mutex_unlock(&global_init_mutex);

  }

}

/**

 * gnutls_global_deinit:

 *

 * This function deinitializes the global data, that were initialized

 * using gnutls_global_init().

 *

 * Since GnuTLS 3.3.0 this function is no longer necessary to be explicitly

 * called. GnuTLS will automatically deinitialize on library destructor. See

 * gnutls_global_init() for disabling the implicit initialization/deinitialization.

 *

 **/

void gnutls_global_deinit(void)

{

  _gnutls_global_deinit(0);

}

/**

 * gnutls_check_version:

 * @req_version: version string to compare with, or %NULL.

 *

 * Check the GnuTLS Library version against the provided string.

 * See %GNUTLS_VERSION for a suitable @req_version string.

 *

 * See also gnutls_check_version_numeric(), which provides this

 * functionality as a macro.

 *

 * Returns: Check that the version of the library is at

 *   minimum the one given as a string in @req_version and return the

 *   actual version string of the library; return %NULL if the

 *   condition is not met.  If %NULL is passed to this function no

 *   check is done and only the version string is returned.

  **/

const char *gnutls_check_version(const char *req_version)

{

  if (!req_version || strverscmp(req_version, VERSION) <= 0)

    return VERSION;

  return NULL;

}

static void _CONSTRUCTOR lib_init(void)

{

  int ret;

  const char *e;

  if (_gnutls_global_init_skip() != 0)

    return;

  e = secure_getenv("GNUTLS_NO_IMPLICIT_INIT");

  if (e != NULL) {

    ret = atoi(e);

    if (ret == 1)

      return;

  }

  e = secure_getenv("GNUTLS_NO_EXPLICIT_INIT");

  if (e != NULL) {

    _gnutls_debug_log(

      "GNUTLS_NO_EXPLICIT_INIT is deprecated; use GNUTLS_NO_IMPLICIT_INIT\n");

    ret = atoi(e);

    if (ret == 1)

      return;

  }

  ret = _gnutls_global_init(1);

  if (ret < 0) {

    fprintf(stderr, "Error in GnuTLS initialization: %s\n",

      gnutls_strerror(ret));

    _gnutls_switch_lib_state(LIB_STATE_ERROR);

  }

}

static void _DESTRUCTOR lib_deinit(void)

{

  int ret;

  const char *e;

  if (_gnutls_global_init_skip() != 0)

    return;

  e = secure_getenv("GNUTLS_NO_IMPLICIT_INIT");

  if (e != NULL) {

    ret = atoi(e);

    if (ret == 1)

      return;

  }

  e = secure_getenv("GNUTLS_NO_EXPLICIT_INIT");

  if (e != NULL) {

    _gnutls_debug_log(

      "GNUTLS_NO_EXPLICIT_INIT is deprecated; use GNUTLS_NO_IMPLICIT_INIT\n");

    ret = atoi(e);

    if (ret == 1)

      return;

  }

  _gnutls_global_deinit(1);

}

static const struct gnutls_library_config_st _gnutls_library_config[] = {

#ifdef FIPS_MODULE_NAME

  { "fips-module-name", FIPS_MODULE_NAME },

#endif

#ifdef FIPS_MODULE_VERSION

  { "fips-module-version", FIPS_MODULE_VERSION },

#endif

  { "libgnutls-soname", GNUTLS_LIBRARY_SONAME },

  { "libnettle-soname", NETTLE_LIBRARY_SONAME },

  { "libhogweed-soname", HOGWEED_LIBRARY_SONAME },

  { "libgmp-soname", GMP_LIBRARY_SONAME },

  { "hardware-features", HW_FEATURES },

  { "tls-features", TLS_FEATURES },

  { "default-system-config", SYSTEM_PRIORITY_FILE },

  { NULL, NULL }

};

/**

 * gnutls_get_library_config:

 *

 * Returns the library configuration as key value pairs.

 * Currently defined keys are:

 *

 *  - fips-module-name: the name of the FIPS140 module

 *

 *  - fips-module-version: the version of the FIPS140 module

 *

 *  - libgnutls-soname: the SONAME of the library itself

 *

 *  - libnettle-soname: the library SONAME of linked libnettle

 *

 *  - libhogweed-soname: the library SONAME of linked libhogweed

 *

 *  - libgmp-soname: the library SONAME of linked libgmp

 *

 *  - hardware-features: enabled hardware support features

 *

 *  - tls-features: enabled TLS protocol features

 *

 * Returns: a NUL-terminated %gnutls_library_config_st array

 *

 * Since: 3.7.3

 */

const gnutls_library_config_st *gnutls_get_library_config(void)

{

  return _gnutls_library_config;

}