lib/gnutls_global.c

   1 /*
   2  * Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2008, 2009, 2010
   3  * Free Software Foundation, Inc.
   4  *
   5  * Author: Nikos Mavrogiannopoulos
   6  *
   7  * This file is part of GnuTLS.
   8  *
   9  * The GnuTLS is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU Lesser General Public License
  11  * as published by the Free Software Foundation; either version 2.1 of
  12  * the License, or (at your option) any later version.
  13  *
  14  * This library is distributed in the hope that it will be useful, but
  15  * WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17  * Lesser General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU Lesser General Public
  20  * License along with this library; if not, write to the Free Software
  21  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
  22  * USA
  23  *
  24  */
  25
  26 #include <gnutls_int.h>
  27 #include <gnutls_errors.h>
  28 #include <libtasn1.h>
  29 #include <gnutls_dh.h>
  30 #include <random.h>
  31 #include <gnutls/pkcs11.h>
  32
  33 #include <gnutls_extensions.h>  /* for _gnutls_ext_init */
  34 #include <gnutls_cryptodev.h>
  35 #include <locks.h>
  36 #include <system.h>
  37
  38 #include "sockets.h"
  39 #include "gettext.h"
  40
  41 /* Minimum library versions we accept. */
  42 #define GNUTLS_MIN_LIBTASN1_VERSION "0.3.4"
  43
  44 /* created by asn1c */
  45 extern const ASN1_ARRAY_TYPE gnutls_asn1_tab[];
  46 extern const ASN1_ARRAY_TYPE pkix_asn1_tab[];
  47
  48 ASN1_TYPE _gnutls_pkix1_asn;
  49 ASN1_TYPE _gnutls_gnutls_asn;
  50
  51 gnutls_log_func _gnutls_log_func;
  52 int _gnutls_log_level = 0;      /* default log level */
  53
  54 /**
  55  * gnutls_global_set_log_function:
  56  * @log_func: it's a log function
  57  *
  58  * This is the function where you set the logging function gnutls is
  59  * going to use.  This function only accepts a character array.
  60  * Normally you may not use this function since it is only used for
  61  * debugging purposes.
  62  *
  63  * gnutls_log_func is of the form,
  64  * void (*gnutls_log_func)( int level, const char*);
  65  **/
  66 void
  67 gnutls_global_set_log_function (gnutls_log_func log_func)
  68 {
  69   _gnutls_log_func = log_func;
  70 }
  71
  72 /**
  73  * gnutls_global_set_time_function:
  74  * @time_func: it's the system time function
  75  *
  76  * This is the function where you can override the default system
  77  * time function.
  78  *
  79  * gnutls_time_func is of the form,
  80  * time_t (*gnutls_time_func)( time*);
  81  **/
  82 void
  83 gnutls_global_set_time_function (gnutls_time_func time_func)
  84 {
  85   gnutls_time = time_func;
  86 }
  87
  88 /**
  89  * gnutls_global_set_log_level:
  90  * @level: it's an integer from 0 to 9.
  91  *
  92  * This is the function that allows you to set the log level.  The
  93  * level is an integer between 0 and 9.  Higher values mean more
  94  * verbosity. The default value is 0.  Larger values should only be
  95  * used with care, since they may reveal sensitive information.
  96  *
  97  * Use a log level over 10 to enable all debugging options.
  98  **/
  99 void
 100 gnutls_global_set_log_level (int level)
 101 {
 102   _gnutls_log_level = level;
 103 }
 104
 105 /**
 106  * gnutls_global_set_mem_functions:
 107  * @alloc_func: it's the default memory allocation function. Like malloc().
 108  * @secure_alloc_func: This is the memory allocation function that will be used for sensitive data.
 109  * @is_secure_func: a function that returns 0 if the memory given is not secure. May be NULL.
 110  * @realloc_func: A realloc function
 111  * @free_func: The function that frees allocated data. Must accept a NULL pointer.
 112  *
 113  * This is the function were you set the memory allocation functions
 114  * gnutls is going to use. By default the libc's allocation functions
 115  * (malloc(), free()), are used by gnutls, to allocate both sensitive
 116  * and not sensitive data.  This function is provided to set the
 117  * memory allocation functions to something other than the defaults
 118  *
 119  * This function must be called before gnutls_global_init() is called.
 120  * This function is not thread safe.
 121  **/
 122 void
 123 gnutls_global_set_mem_functions (gnutls_alloc_function alloc_func,
 124                                  gnutls_alloc_function secure_alloc_func,
 125                                  gnutls_is_secure_function is_secure_func,
 126                                  gnutls_realloc_function realloc_func,
 127                                  gnutls_free_function free_func)
 128 {
 129   gnutls_secure_malloc = secure_alloc_func;
 130   gnutls_malloc = alloc_func;
 131   gnutls_realloc = realloc_func;
 132   gnutls_free = free_func;
 133
 134   if (is_secure_func != NULL)
 135     _gnutls_is_secure_memory = is_secure_func;
 136   else
 137     _gnutls_is_secure_memory = _gnutls_is_secure_mem_null;
 138
 139   /* if using the libc's default malloc
 140    * use libc's calloc as well.
 141    */
 142   if (gnutls_malloc == malloc)
 143     {
 144       gnutls_calloc = calloc;
 145     }
 146   else
 147     {                           /* use the included ones */
 148       gnutls_calloc = _gnutls_calloc;
 149     }
 150   gnutls_strdup = _gnutls_strdup;
 151
 152 }
 153
 154 static int _gnutls_init = 0;
 155
 156
 157 /**
 158  * gnutls_global_init:
 159  *
 160  * This function initializes the global data to defaults.  Every
 161  * gnutls application has a global data which holds common parameters
 162  * shared by gnutls session structures.  You should call
 163  * gnutls_global_deinit() when gnutls usage is no longer needed
 164  *
 165  * Note that this function will also initialize the underlying crypto
 166  * backend, if it has not been initialized before.
 167  *
 168  * This function increment a global counter, so that
 169  * gnutls_global_deinit() only releases resources when it has been
 170  * called as many times as gnutls_global_init().  This is useful when
 171  * GnuTLS is used by more than one library in an application.  This
 172  * function can be called many times, but will only do something the
 173  * first time.
 174  *
 175  * Note!  This function is not thread safe.  If two threads call this
 176  * function simultaneously, they can cause a race between checking
 177  * the global counter and incrementing it, causing both threads to
 178  * execute the library initialization code.  That would lead to a
 179  * memory leak.  To handle this, your application could invoke this
 180  * function after aquiring a thread mutex.  To ignore the potential
 181  * memory leak is also an option.
 182  *
 183  * Returns: On success, %GNUTLS_E_SUCCESS (zero) is returned,
 184  *   otherwise an error code is returned.
 185  **/
 186 int
 187 gnutls_global_init (void)
 188 {
 189   int result = 0;
 190   int res;
 191
 192   if (_gnutls_init++)
 193     goto out;
 194
 195   if (gl_sockets_startup (SOCKETS_1_1))
 196     return GNUTLS_E_LIBRARY_VERSION_MISMATCH;
 197
 198   bindtextdomain (PACKAGE, LOCALEDIR);
 199
 200   res = gnutls_crypto_init ();
 201   if (res != 0)
 202     {
 203       gnutls_assert ();
 204       return GNUTLS_E_CRYPTO_INIT_FAILED;
 205     }
 206
 207   /* initialize ASN.1 parser
 208    * This should not deal with files in the final
 209    * version.
 210    */
 211   if (asn1_check_version (GNUTLS_MIN_LIBTASN1_VERSION) == NULL)
 212     {
 213       gnutls_assert ();
 214       _gnutls_debug_log ("Checking for libtasn1 failed: %s < %s\n",
 215                          asn1_check_version (NULL),
 216                          GNUTLS_MIN_LIBTASN1_VERSION);
 217       return GNUTLS_E_INCOMPATIBLE_LIBTASN1_LIBRARY;
 218     }
 219
 220   res = asn1_array2tree (pkix_asn1_tab, &_gnutls_pkix1_asn, NULL);
 221   if (res != ASN1_SUCCESS)
 222     {
 223       result = _gnutls_asn2err (res);
 224       goto out;
 225     }
 226
 227   res = asn1_array2tree (gnutls_asn1_tab, &_gnutls_gnutls_asn, NULL);
 228   if (res != ASN1_SUCCESS)
 229     {
 230       asn1_delete_structure (&_gnutls_pkix1_asn);
 231       result = _gnutls_asn2err (res);
 232       goto out;
 233     }
 234
 235   /* Initialize the random generator */
 236   result = _gnutls_rnd_init ();
 237   if (result < 0)
 238     {
 239       gnutls_assert ();
 240       goto out;
 241     }
 242
 243   /* Initialize the default TLS extensions */
 244   result = _gnutls_ext_init ();
 245   if (result < 0)
 246     {
 247       gnutls_assert ();
 248       goto out;
 249     }
 250
 251 #ifdef ENABLE_PKCS11
 252   gnutls_pkcs11_init (GNUTLS_PKCS11_FLAG_AUTO, NULL);
 253 #endif
 254
 255   _gnutls_cryptodev_init ();
 256
 257 out:
 258   return result;
 259 }
 260
 261 /**
 262  * gnutls_global_deinit:
 263  *
 264  * This function deinitializes the global data, that were initialized
 265  * using gnutls_global_init().
 266  *
 267  * Note!  This function is not thread safe.  See the discussion for
 268  * gnutls_global_init() for more information.
 269  **/
 270 void
 271 gnutls_global_deinit (void)
 272 {
 273   if (_gnutls_init == 1)
 274     {
 275       gl_sockets_cleanup ();
 276       _gnutls_rnd_deinit ();
 277       _gnutls_ext_deinit ();
 278       asn1_delete_structure (&_gnutls_gnutls_asn);
 279       asn1_delete_structure (&_gnutls_pkix1_asn);
 280       _gnutls_crypto_deregister ();
 281       _gnutls_cryptodev_deinit ();
 282 #ifdef ENABLE_PKCS11
 283       gnutls_pkcs11_deinit ();
 284 #endif
 285     }
 286   _gnutls_init--;
 287 }
 288
 289 /* These functions should be elsewere. Kept here for
 290  * historical reasons.
 291  */
 292
 293
 294 /**
 295  * gnutls_check_version:
 296  * @req_version: version string to compare with, or %NULL.
 297  *
 298  * Check GnuTLS Library version.
 299  *
 300  * See %GNUTLS_VERSION for a suitable @req_version string.
 301  *
 302  * Return value: Check that the version of the library is at
 303  *   minimum the one given as a string in @req_version and return the
 304  *   actual version string of the library; return %NULL if the
 305  *   condition is not met.  If %NULL is passed to this function no
 306  *   check is done and only the version string is returned.
 307   **/
 308 const char *
 309 gnutls_check_version (const char *req_version)
 310 {
 311   if (!req_version || strverscmp (req_version, VERSION) <= 0)
 312     return VERSION;
 313
 314   return NULL;
 315 }