gio/gtlscertificate.c

   1 /* GIO - GLib Input, Output and Certificateing Library
   2  *
   3  * Copyright (C) 2010 Red Hat, Inc.
   4  *
   5  * This library is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU Lesser General Public
   7  * License as published by the Free Software Foundation; either
   8  * version 2.1 of the License, or (at your option) any later version.
   9  *
  10  * This library is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * Lesser General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU Lesser General
  16  * Public License along with this library; if not, see <http://www.gnu.org/licenses/>.
  17  */
  18
  19 #include "config.h"
  20
  21 #include "gtlscertificate.h"
  22
  23 #include <string.h>
  24 #include "ginitable.h"
  25 #include "gtlsbackend.h"
  26 #include "gtlsconnection.h"
  27 #include "glibintl.h"
  28
  29 /**
  30  * SECTION:gtlscertificate
  31  * @title: GTlsCertificate
  32  * @short_description: TLS certificate
  33  * @include: gio/gio.h
  34  * @see_also: #GTlsConnection
  35  *
  36  * A certificate used for TLS authentication and encryption.
  37  * This can represent either a certificate only (eg, the certificate
  38  * received by a client from a server), or the combination of
  39  * a certificate and a private key (which is needed when acting as a
  40  * #GTlsServerConnection).
  41  *
  42  * Since: 2.28
  43  */
  44
  45 /**
  46  * GTlsCertificate:
  47  *
  48  * Abstract base class for TLS certificate types.
  49  *
  50  * Since: 2.28
  51  */
  52
  53 G_DEFINE_ABSTRACT_TYPE (GTlsCertificate, g_tls_certificate, G_TYPE_OBJECT)
  54
  55 enum
  56 {
  57   PROP_0,
  58
  59   PROP_CERTIFICATE,
  60   PROP_CERTIFICATE_PEM,
  61   PROP_PRIVATE_KEY,
  62   PROP_PRIVATE_KEY_PEM,
  63   PROP_ISSUER
  64 };
  65
  66 static void
  67 g_tls_certificate_init (GTlsCertificate *cert)
  68 {
  69 }
  70
  71 static void
  72 g_tls_certificate_get_property (GObject    *object,
  73                                 guint       prop_id,
  74                                 GValue     *value,
  75                                 GParamSpec *pspec)
  76 {
  77   G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
  78 }
  79
  80 static void
  81 g_tls_certificate_set_property (GObject      *object,
  82                                 guint         prop_id,
  83                                 const GValue *value,
  84                                 GParamSpec   *pspec)
  85 {
  86   G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
  87 }
  88
  89 static void
  90 g_tls_certificate_class_init (GTlsCertificateClass *class)
  91 {
  92   GObjectClass *gobject_class = G_OBJECT_CLASS (class);
  93
  94   gobject_class->set_property = g_tls_certificate_set_property;
  95   gobject_class->get_property = g_tls_certificate_get_property;
  96
  97   /**
  98    * GTlsCertificate:certificate:
  99    *
 100    * The DER (binary) encoded representation of the certificate.
 101    * This property and the #GTlsCertificate:certificate-pem property
 102    * represent the same data, just in different forms.
 103    *
 104    * Since: 2.28
 105    */
 106   g_object_class_install_property (gobject_class, PROP_CERTIFICATE,
 107                                    g_param_spec_boxed ("certificate",
 108                                                        P_("Certificate"),
 109                                                        P_("The DER representation of the certificate"),
 110                                                        G_TYPE_BYTE_ARRAY,
 111                                                        G_PARAM_READWRITE |
 112                                                        G_PARAM_CONSTRUCT_ONLY |
 113                                                        G_PARAM_STATIC_STRINGS));
 114   /**
 115    * GTlsCertificate:certificate-pem:
 116    *
 117    * The PEM (ASCII) encoded representation of the certificate.
 118    * This property and the #GTlsCertificate:certificate
 119    * property represent the same data, just in different forms.
 120    *
 121    * Since: 2.28
 122    */
 123   g_object_class_install_property (gobject_class, PROP_CERTIFICATE_PEM,
 124                                    g_param_spec_string ("certificate-pem",
 125                                                         P_("Certificate (PEM)"),
 126                                                         P_("The PEM representation of the certificate"),
 127                                                         NULL,
 128                                                         G_PARAM_READWRITE |
 129                                                         G_PARAM_CONSTRUCT_ONLY |
 130                                                         G_PARAM_STATIC_STRINGS));
 131   /**
 132    * GTlsCertificate:private-key:
 133    *
 134    * The DER (binary) encoded representation of the certificate's
 135    * private key, in either PKCS#1 format or unencrypted PKCS#8
 136    * format. This property (or the #GTlsCertificate:private-key-pem
 137    * property) can be set when constructing a key (eg, from a file),
 138    * but cannot be read.
 139    *
 140    * PKCS#8 format is supported since 2.32; earlier releases only
 141    * support PKCS#1. You can use the `openssl rsa`
 142    * tool to convert PKCS#8 keys to PKCS#1.
 143    *
 144    * Since: 2.28
 145    */
 146   g_object_class_install_property (gobject_class, PROP_PRIVATE_KEY,
 147                                    g_param_spec_boxed ("private-key",
 148                                                        P_("Private key"),
 149                                                        P_("The DER representation of the certificate’s private key"),
 150                                                        G_TYPE_BYTE_ARRAY,
 151                                                        G_PARAM_WRITABLE |
 152                                                        G_PARAM_CONSTRUCT_ONLY |
 153                                                        G_PARAM_STATIC_STRINGS));
 154   /**
 155    * GTlsCertificate:private-key-pem:
 156    *
 157    * The PEM (ASCII) encoded representation of the certificate's
 158    * private key in either PKCS#1 format ("`BEGIN RSA PRIVATE
 159    * KEY`") or unencrypted PKCS#8 format ("`BEGIN
 160    * PRIVATE KEY`"). This property (or the
 161    * #GTlsCertificate:private-key property) can be set when
 162    * constructing a key (eg, from a file), but cannot be read.
 163    *
 164    * PKCS#8 format is supported since 2.32; earlier releases only
 165    * support PKCS#1. You can use the `openssl rsa`
 166    * tool to convert PKCS#8 keys to PKCS#1.
 167    *
 168    * Since: 2.28
 169    */
 170   g_object_class_install_property (gobject_class, PROP_PRIVATE_KEY_PEM,
 171                                    g_param_spec_string ("private-key-pem",
 172                                                         P_("Private key (PEM)"),
 173                                                         P_("The PEM representation of the certificate’s private key"),
 174                                                         NULL,
 175                                                         G_PARAM_WRITABLE |
 176                                                         G_PARAM_CONSTRUCT_ONLY |
 177                                                         G_PARAM_STATIC_STRINGS));
 178   /**
 179    * GTlsCertificate:issuer:
 180    *
 181    * A #GTlsCertificate representing the entity that issued this
 182    * certificate. If %NULL, this means that the certificate is either
 183    * self-signed, or else the certificate of the issuer is not
 184    * available.
 185    *
 186    * Since: 2.28
 187    */
 188   g_object_class_install_property (gobject_class, PROP_ISSUER,
 189                                    g_param_spec_object ("issuer",
 190                                                         P_("Issuer"),
 191                                                         P_("The certificate for the issuing entity"),
 192                                                         G_TYPE_TLS_CERTIFICATE,
 193                                                         G_PARAM_READWRITE |
 194                                                         G_PARAM_CONSTRUCT_ONLY |
 195                                                         G_PARAM_STATIC_STRINGS));
 196 }
 197
 198 static GTlsCertificate *
 199 g_tls_certificate_new_internal (const gchar      *certificate_pem,
 200                                 const gchar      *private_key_pem,
 201                                 GTlsCertificate  *issuer,
 202                                 GError          **error)
 203 {
 204   GObject *cert;
 205   GTlsBackend *backend;
 206
 207   backend = g_tls_backend_get_default ();
 208
 209   cert = g_initable_new (g_tls_backend_get_certificate_type (backend),
 210                          NULL, error,
 211                          "certificate-pem", certificate_pem,
 212                          "private-key-pem", private_key_pem,
 213                          "issuer", issuer,
 214                          NULL);
 215
 216   return G_TLS_CERTIFICATE (cert);
 217 }
 218
 219 #define PEM_CERTIFICATE_HEADER     "-----BEGIN CERTIFICATE-----"
 220 #define PEM_CERTIFICATE_FOOTER     "-----END CERTIFICATE-----"
 221 #define PEM_PKCS1_PRIVKEY_HEADER   "-----BEGIN RSA PRIVATE KEY-----"
 222 #define PEM_PKCS1_PRIVKEY_FOOTER   "-----END RSA PRIVATE KEY-----"
 223 #define PEM_PKCS8_PRIVKEY_HEADER   "-----BEGIN PRIVATE KEY-----"
 224 #define PEM_PKCS8_PRIVKEY_FOOTER   "-----END PRIVATE KEY-----"
 225 #define PEM_PKCS8_ENCRYPTED_HEADER "-----BEGIN ENCRYPTED PRIVATE KEY-----"
 226 #define PEM_PKCS8_ENCRYPTED_FOOTER "-----END ENCRYPTED PRIVATE KEY-----"
 227
 228 static gchar *
 229 parse_private_key (const gchar *data,
 230                    gsize data_len,
 231                    gboolean required,
 232                    GError **error)
 233 {
 234   const gchar *start, *end, *footer;
 235
 236   start = g_strstr_len (data, data_len, PEM_PKCS1_PRIVKEY_HEADER);
 237   if (start)
 238     footer = PEM_PKCS1_PRIVKEY_FOOTER;
 239   else
 240     {
 241       start = g_strstr_len (data, data_len, PEM_PKCS8_PRIVKEY_HEADER);
 242       if (start)
 243         footer = PEM_PKCS8_PRIVKEY_FOOTER;
 244       else
 245         {
 246           start = g_strstr_len (data, data_len, PEM_PKCS8_ENCRYPTED_HEADER);
 247           if (start)
 248             {
 249               g_set_error_literal (error, G_TLS_ERROR, G_TLS_ERROR_BAD_CERTIFICATE,
 250                                    _("Cannot decrypt PEM-encoded private key"));
 251             }
 252           else if (required)
 253             {
 254               g_set_error_literal (error, G_TLS_ERROR, G_TLS_ERROR_BAD_CERTIFICATE,
 255                                    _("No PEM-encoded private key found"));
 256             }
 257           return NULL;
 258         }
 259     }
 260
 261   end = g_strstr_len (start, data_len - (data - start), footer);
 262   if (!end)
 263     {
 264       g_set_error_literal (error, G_TLS_ERROR, G_TLS_ERROR_BAD_CERTIFICATE,
 265                            _("Could not parse PEM-encoded private key"));
 266       return NULL;
 267     }
 268   end += strlen (footer);
 269   while (*end == '\r' || *end == '\n')
 270     end++;
 271
 272   return g_strndup (start, end - start);
 273 }
 274
 275
 276 static gchar *
 277 parse_next_pem_certificate (const gchar **data,
 278                             const gchar  *data_end,
 279                             gboolean      required,
 280                             GError      **error)
 281 {
 282   const gchar *start, *end;
 283
 284   start = g_strstr_len (*data, data_end - *data, PEM_CERTIFICATE_HEADER);
 285   if (!start)
 286     {
 287       if (required)
 288         {
 289           g_set_error_literal (error, G_TLS_ERROR, G_TLS_ERROR_BAD_CERTIFICATE,
 290                                _("No PEM-encoded certificate found"));
 291         }
 292       return NULL;
 293     }
 294
 295   end = g_strstr_len (start, data_end - start, PEM_CERTIFICATE_FOOTER);
 296   if (!end)
 297     {
 298       g_set_error_literal (error, G_TLS_ERROR, G_TLS_ERROR_BAD_CERTIFICATE,
 299                            _("Could not parse PEM-encoded certificate"));
 300       return NULL;
 301     }
 302   end += strlen (PEM_CERTIFICATE_FOOTER);
 303   while (*end == '\r' || *end == '\n')
 304     end++;
 305
 306   *data = end;
 307
 308   return g_strndup (start, end - start);
 309 }
 310
 311 static GSList *
 312 parse_and_create_certificate_list (const gchar  *data,
 313                                    gsize         data_len,
 314                                    GError      **error)
 315 {
 316   GSList *first_pem_list = NULL, *pem_list = NULL;
 317   gchar *first_pem;
 318   const gchar *p, *end;
 319
 320   p = data;
 321   end = p + data_len;
 322
 323   /* Make sure we can load, at least, one certificate. */
 324   first_pem = parse_next_pem_certificate (&p, end, TRUE, error);
 325   if (!first_pem)
 326     return NULL;
 327
 328   /* Create a list with a single element. If we load more certificates
 329    * below, we will concatenate the two lists at the end. */
 330   first_pem_list = g_slist_prepend (first_pem_list, first_pem);
 331
 332   /* If we read one certificate successfully, let's see if we can read
 333    * some more. If not, we will simply return a list with the first one.
 334    */
 335   while (p && *p)
 336     {
 337       gchar *cert_pem;
 338       GError *error = NULL;
 339
 340       cert_pem = parse_next_pem_certificate (&p, end, FALSE, &error);
 341       if (error)
 342         {
 343           g_slist_free_full (pem_list, g_free);
 344           g_error_free (error);
 345           return first_pem_list;
 346         }
 347       else if (!cert_pem)
 348         {
 349           break;
 350         }
 351
 352       pem_list = g_slist_prepend (pem_list, cert_pem);
 353     }
 354
 355   pem_list = g_slist_concat (pem_list, first_pem_list);
 356
 357   return pem_list;
 358 }
 359
 360 static GTlsCertificate *
 361 create_certificate_chain_from_list (GSList       *pem_list,
 362                                     const gchar  *key_pem)
 363 {
 364   GTlsCertificate *cert = NULL, *issuer = NULL, *root = NULL;
 365   GTlsCertificateFlags flags;
 366   GSList *pem;
 367
 368   pem = pem_list;
 369   while (pem)
 370     {
 371       const gchar *key = NULL;
 372
 373       /* Private key belongs only to the first certificate. */
 374       if (!pem->next)
 375         key = key_pem;
 376
 377       /* We assume that the whole file is a certificate chain, so we use
 378        * each certificate as the issuer of the next one (list is in
 379        * reverse order).
 380        */
 381       issuer = cert;
 382       cert = g_tls_certificate_new_internal (pem->data, key, issuer, NULL);
 383       if (issuer)
 384         g_object_unref (issuer);
 385
 386       if (!cert)
 387         return NULL;
 388
 389       /* root will point to the last certificate in the file. */
 390       if (!root)
 391         root = cert;
 392
 393       pem = g_slist_next (pem);
 394     }
 395
 396   /* Verify that the certificates form a chain. (We don't care at this
 397    * point if there are other problems with it.)
 398    */
 399   flags = g_tls_certificate_verify (cert, NULL, root);
 400   if (flags & G_TLS_CERTIFICATE_UNKNOWN_CA)
 401     {
 402       /* It wasn't a chain, it's just a bunch of unrelated certs. */
 403       g_clear_object (&cert);
 404     }
 405
 406   return cert;
 407 }
 408
 409 static GTlsCertificate *
 410 parse_and_create_certificate (const gchar  *data,
 411                               gsize         data_len,
 412                               const gchar  *key_pem,
 413                               GError      **error)
 414
 415 {
 416   GSList *pem_list;
 417   GTlsCertificate *cert;
 418
 419   pem_list = parse_and_create_certificate_list (data, data_len, error);
 420   if (!pem_list)
 421     return NULL;
 422
 423   /* We don't pass the error here because, if it fails, we still want to
 424    * load and return the first certificate.
 425    */
 426   cert = create_certificate_chain_from_list (pem_list, key_pem);
 427   if (!cert)
 428     {
 429       GSList *last = NULL;
 430
 431       /* Get the first certificate (which is the last one as the list is
 432        * in reverse order).
 433        */
 434       last = g_slist_last (pem_list);
 435
 436       cert = g_tls_certificate_new_internal (last->data, key_pem, NULL, error);
 437     }
 438
 439   g_slist_free_full (pem_list, g_free);
 440
 441   return cert;
 442 }
 443
 444 /**
 445  * g_tls_certificate_new_from_pem:
 446  * @data: PEM-encoded certificate data
 447  * @length: the length of @data, or -1 if it's 0-terminated.
 448  * @error: #GError for error reporting, or %NULL to ignore.
 449  *
 450  * Creates a #GTlsCertificate from the PEM-encoded data in @data. If
 451  * @data includes both a certificate and a private key, then the
 452  * returned certificate will include the private key data as well. (See
 453  * the #GTlsCertificate:private-key-pem property for information about
 454  * supported formats.)
 455  *
 456  * The returned certificate will be the first certificate found in
 457  * @data. As of GLib 2.44, if @data contains more certificates it will
 458  * try to load a certificate chain. All certificates will be verified in
 459  * the order found (top-level certificate should be the last one in the
 460  * file) and the #GTlsCertificate:issuer property of each certificate
 461  * will be set accordingly if the verification succeeds. If any
 462  * certificate in the chain cannot be verified, the first certificate in
 463  * the file will still be returned.
 464  *
 465  * Returns: the new certificate, or %NULL if @data is invalid
 466  *
 467  * Since: 2.28
 468  */
 469 GTlsCertificate *
 470 g_tls_certificate_new_from_pem  (const gchar  *data,
 471                                  gssize        length,
 472                                  GError      **error)
 473 {
 474   GError *child_error = NULL;
 475   gchar *key_pem;
 476   GTlsCertificate *cert;
 477
 478   g_return_val_if_fail (data != NULL, NULL);
 479   g_return_val_if_fail (error == NULL || *error == NULL, NULL);
 480
 481   if (length == -1)
 482     length = strlen (data);
 483
 484   key_pem = parse_private_key (data, length, FALSE, &child_error);
 485   if (child_error != NULL)
 486     {
 487       g_propagate_error (error, child_error);
 488       return NULL;
 489     }
 490
 491   cert = parse_and_create_certificate (data, length, key_pem, error);
 492   g_free (key_pem);
 493
 494   return cert;
 495 }
 496
 497 /**
 498  * g_tls_certificate_new_from_file:
 499  * @file: (type filename): file containing a PEM-encoded certificate to import
 500  * @error: #GError for error reporting, or %NULL to ignore.
 501  *
 502  * Creates a #GTlsCertificate from the PEM-encoded data in @file. The
 503  * returned certificate will be the first certificate found in @file. As
 504  * of GLib 2.44, if @file contains more certificates it will try to load
 505  * a certificate chain. All certificates will be verified in the order
 506  * found (top-level certificate should be the last one in the file) and
 507  * the #GTlsCertificate:issuer property of each certificate will be set
 508  * accordingly if the verification succeeds. If any certificate in the
 509  * chain cannot be verified, the first certificate in the file will
 510  * still be returned.
 511  *
 512  * If @file cannot be read or parsed, the function will return %NULL and
 513  * set @error. Otherwise, this behaves like
 514  * g_tls_certificate_new_from_pem().
 515  *
 516  * Returns: the new certificate, or %NULL on error
 517  *
 518  * Since: 2.28
 519  */
 520 GTlsCertificate *
 521 g_tls_certificate_new_from_file (const gchar  *file,
 522                                  GError      **error)
 523 {
 524   GTlsCertificate *cert;
 525   gchar *contents;
 526   gsize length;
 527
 528   if (!g_file_get_contents (file, &contents, &length, error))
 529     return NULL;
 530
 531   cert = g_tls_certificate_new_from_pem (contents, length, error);
 532   g_free (contents);
 533   return cert;
 534 }
 535
 536 /**
 537  * g_tls_certificate_new_from_files:
 538  * @cert_file: (type filename): file containing one or more PEM-encoded
 539  *     certificates to import
 540  * @key_file: (type filename): file containing a PEM-encoded private key
 541  *     to import
 542  * @error: #GError for error reporting, or %NULL to ignore.
 543  *
 544  * Creates a #GTlsCertificate from the PEM-encoded data in @cert_file
 545  * and @key_file. The returned certificate will be the first certificate
 546  * found in @cert_file. As of GLib 2.44, if @cert_file contains more
 547  * certificates it will try to load a certificate chain. All
 548  * certificates will be verified in the order found (top-level
 549  * certificate should be the last one in the file) and the
 550  * #GTlsCertificate:issuer property of each certificate will be set
 551  * accordingly if the verification succeeds. If any certificate in the
 552  * chain cannot be verified, the first certificate in the file will
 553  * still be returned.
 554  *
 555  * If either file cannot be read or parsed, the function will return
 556  * %NULL and set @error. Otherwise, this behaves like
 557  * g_tls_certificate_new_from_pem().
 558  *
 559  * Returns: the new certificate, or %NULL on error
 560  *
 561  * Since: 2.28
 562  */
 563 GTlsCertificate *
 564 g_tls_certificate_new_from_files (const gchar  *cert_file,
 565                                   const gchar  *key_file,
 566                                   GError      **error)
 567 {
 568   GTlsCertificate *cert;
 569   gchar *cert_data, *key_data;
 570   gsize cert_len, key_len;
 571   gchar *key_pem;
 572
 573   if (!g_file_get_contents (key_file, &key_data, &key_len, error))
 574     return NULL;
 575
 576   key_pem = parse_private_key (key_data, key_len, TRUE, error);
 577   g_free (key_data);
 578   if (!key_pem)
 579     return NULL;
 580
 581   if (!g_file_get_contents (cert_file, &cert_data, &cert_len, error))
 582     {
 583       g_free (key_pem);
 584       return NULL;
 585     }
 586
 587   cert = parse_and_create_certificate (cert_data, cert_len, key_pem, error);
 588   g_free (cert_data);
 589   g_free (key_pem);
 590   return cert;
 591 }
 592
 593 /**
 594  * g_tls_certificate_list_new_from_file:
 595  * @file: (type filename): file containing PEM-encoded certificates to import
 596  * @error: #GError for error reporting, or %NULL to ignore.
 597  *
 598  * Creates one or more #GTlsCertificates from the PEM-encoded
 599  * data in @file. If @file cannot be read or parsed, the function will
 600  * return %NULL and set @error. If @file does not contain any
 601  * PEM-encoded certificates, this will return an empty list and not
 602  * set @error.
 603  *
 604  * Returns: (element-type Gio.TlsCertificate) (transfer full): a
 605  * #GList containing #GTlsCertificate objects. You must free the list
 606  * and its contents when you are done with it.
 607  *
 608  * Since: 2.28
 609  */
 610 GList *
 611 g_tls_certificate_list_new_from_file (const gchar  *file,
 612                                       GError      **error)
 613 {
 614   GQueue queue = G_QUEUE_INIT;
 615   gchar *contents, *end;
 616   const gchar *p;
 617   gsize length;
 618
 619   if (!g_file_get_contents (file, &contents, &length, error))
 620     return NULL;
 621
 622   end = contents + length;
 623   p = contents;
 624   while (p && *p)
 625     {
 626       gchar *cert_pem;
 627       GTlsCertificate *cert = NULL;
 628       GError *parse_error = NULL;
 629
 630       cert_pem = parse_next_pem_certificate (&p, end, FALSE, &parse_error);
 631       if (cert_pem)
 632         {
 633           cert = g_tls_certificate_new_internal (cert_pem, NULL, NULL, &parse_error);
 634           g_free (cert_pem);
 635         }
 636       if (!cert)
 637         {
 638           if (parse_error)
 639             {
 640               g_propagate_error (error, parse_error);
 641               g_list_free_full (queue.head, g_object_unref);
 642               queue.head = NULL;
 643             }
 644           break;
 645         }
 646       g_queue_push_tail (&queue, cert);
 647     }
 648
 649   g_free (contents);
 650   return queue.head;
 651 }
 652
 653
 654 /**
 655  * g_tls_certificate_get_issuer:
 656  * @cert: a #GTlsCertificate
 657  *
 658  * Gets the #GTlsCertificate representing @cert's issuer, if known
 659  *
 660  * Returns: (transfer none): The certificate of @cert's issuer,
 661  * or %NULL if @cert is self-signed or signed with an unknown
 662  * certificate.
 663  *
 664  * Since: 2.28
 665  */
 666 GTlsCertificate *
 667 g_tls_certificate_get_issuer (GTlsCertificate  *cert)
 668 {
 669   GTlsCertificate *issuer;
 670
 671   g_object_get (G_OBJECT (cert), "issuer", &issuer, NULL);
 672   if (issuer)
 673     g_object_unref (issuer);
 674
 675   return issuer;
 676 }
 677
 678 /**
 679  * g_tls_certificate_verify:
 680  * @cert: a #GTlsCertificate
 681  * @identity: (nullable): the expected peer identity
 682  * @trusted_ca: (nullable): the certificate of a trusted authority
 683  *
 684  * This verifies @cert and returns a set of #GTlsCertificateFlags
 685  * indicating any problems found with it. This can be used to verify a
 686  * certificate outside the context of making a connection, or to
 687  * check a certificate against a CA that is not part of the system
 688  * CA database.
 689  *
 690  * If @identity is not %NULL, @cert's name(s) will be compared against
 691  * it, and %G_TLS_CERTIFICATE_BAD_IDENTITY will be set in the return
 692  * value if it does not match. If @identity is %NULL, that bit will
 693  * never be set in the return value.
 694  *
 695  * If @trusted_ca is not %NULL, then @cert (or one of the certificates
 696  * in its chain) must be signed by it, or else
 697  * %G_TLS_CERTIFICATE_UNKNOWN_CA will be set in the return value. If
 698  * @trusted_ca is %NULL, that bit will never be set in the return
 699  * value.
 700  *
 701  * (All other #GTlsCertificateFlags values will always be set or unset
 702  * as appropriate.)
 703  *
 704  * Returns: the appropriate #GTlsCertificateFlags
 705  *
 706  * Since: 2.28
 707  */
 708 GTlsCertificateFlags
 709 g_tls_certificate_verify (GTlsCertificate     *cert,
 710                           GSocketConnectable  *identity,
 711                           GTlsCertificate     *trusted_ca)
 712 {
 713   return G_TLS_CERTIFICATE_GET_CLASS (cert)->verify (cert, identity, trusted_ca);
 714 }
 715
 716 /**
 717  * g_tls_certificate_is_same:
 718  * @cert_one: first certificate to compare
 719  * @cert_two: second certificate to compare
 720  *
 721  * Check if two #GTlsCertificate objects represent the same certificate.
 722  * The raw DER byte data of the two certificates are checked for equality.
 723  * This has the effect that two certificates may compare equal even if
 724  * their #GTlsCertificate:issuer, #GTlsCertificate:private-key, or
 725  * #GTlsCertificate:private-key-pem properties differ.
 726  *
 727  * Returns: whether the same or not
 728  *
 729  * Since: 2.34
 730  */
 731 gboolean
 732 g_tls_certificate_is_same (GTlsCertificate     *cert_one,
 733                            GTlsCertificate     *cert_two)
 734 {
 735   GByteArray *b1, *b2;
 736   gboolean equal;
 737
 738   g_return_val_if_fail (G_IS_TLS_CERTIFICATE (cert_one), FALSE);
 739   g_return_val_if_fail (G_IS_TLS_CERTIFICATE (cert_two), FALSE);
 740
 741   g_object_get (cert_one, "certificate", &b1, NULL);
 742   g_object_get (cert_two, "certificate", &b2, NULL);
 743
 744   equal = (b1->len == b2->len &&
 745            memcmp (b1->data, b2->data, b1->len) == 0);
 746
 747   g_byte_array_unref (b1);
 748   g_byte_array_unref (b2);
 749
 750   return equal;
 751 }