/*

 * 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 <http://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 <extensions.h>	/* for _gnutls_ext_init */

#include <supplemental.h> /* for _gnutls_supplemental_deinit */

#include <locks.h>

#include <system.h>

#include <accelerated/cryptodev.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_ARRAY_TYPE gnutls_asn1_tab[];

extern const ASN1_ARRAY_TYPE pkix_asn1_tab[];

void *_gnutls_file_mutex;

void *_gnutls_pkcs11_mutex;

ASN1_TYPE _gnutls_pkix1_asn = ASN1_TYPE_EMPTY;

ASN1_TYPE _gnutls_gnutls_asn = ASN1_TYPE_EMPTY;

gnutls_log_func _gnutls_log_func = NULL;

gnutls_audit_log_func _gnutls_audit_log_func = NULL;

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

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;

}

/**

 * 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;

}

/**

 * 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_EXPLICIT_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.

 *

 * 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) {

		GNUTLS_STATIC_MUTEX_LOCK(global_init_mutex);

	}

	_gnutls_init++;

	if (_gnutls_init > 1) {

		if (_gnutls_init == 2 && _gnutls_init_ret == 0) {

			/* some applications may close the urandom fd 

			 * before calling gnutls_global_init(). in that

			 * case reopen it */

			ret = _gnutls_rnd_check();

			if (ret < 0) {

				gnutls_assert();

				goto out;

			}

		}

		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 = ASN1_TYPE_EMPTY;

	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_ext_init();

	if (ret < 0) {

		gnutls_assert();

		goto out;

	}

	ret = gnutls_mutex_init(&_gnutls_file_mutex);

	if (ret < 0) {

		gnutls_assert();

		goto out;

	}

	ret = gnutls_mutex_init(&_gnutls_pkcs11_mutex);

	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 */

		ret = _gnutls_fips_perform_self_checks1();

		if (res != 2) {

			if (ret < 0) {

				gnutls_assert();

				goto out;

			}

		}

	}

#endif

	_gnutls_register_accel_crypto();

	_gnutls_cryptodev_init();

	_gnutls_load_system_priorities();

#ifdef ENABLE_FIPS140

	/* These self tests are performed on the overriden algorithms

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

	 * intentionally */

	if (res != 0) {

		ret = _gnutls_fips_perform_self_checks2();

		if (res != 2) {

			if (ret < 0) {

				gnutls_assert();

				goto out;

			}

		}

		_gnutls_fips_mode_reset_zombie();

	}

#endif

	_gnutls_switch_lib_state(LIB_STATE_OPERATIONAL);

	ret = 0;

      out:

	_gnutls_init_ret = ret;

	if (!constructor) {

		GNUTLS_STATIC_MUTEX_UNLOCK(global_init_mutex);

	}

	return ret;

}

static void _gnutls_global_deinit(unsigned destructor)

{

	if (!destructor) {

		GNUTLS_STATIC_MUTEX_LOCK(global_init_mutex);

	}

	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_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

		gnutls_mutex_deinit(&_gnutls_file_mutex);

		gnutls_mutex_deinit(&_gnutls_pkcs11_mutex);

	} else {

		if (_gnutls_init > 0)

			_gnutls_init--;

	}

 fail:

	if (!destructor) {

		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_EXPLICIT_INIT");

	if (e != NULL) {

		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)

{

	const char *e;

	if (_gnutls_global_init_skip() != 0)

		return;

	e = secure_getenv("GNUTLS_NO_EXPLICIT_INIT");

	if (e != NULL) {

		int ret = atoi(e);

		if (ret == 1)

			return;

	}

	_gnutls_global_deinit(1);

}