src/common/ssl_certificate.c

   1 /*
   2  * Claws Mail -- a GTK based, lightweight, and fast e-mail client
   3  * Copyright (C) 1999-2016 Colin Leroy and the Claws Mail team
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 3 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program 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
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  17  */
  18
  19 #ifdef HAVE_CONFIG_H
  20 #  include "config.h"
  21 #include "claws-features.h"
  22 #endif
  23
  24 #ifdef USE_GNUTLS
  25 #include <gnutls/gnutls.h>
  26 #include <gnutls/x509.h>
  27 #include <gnutls/pkcs12.h>
  28 #include <sys/stat.h>
  29 #include <unistd.h>
  30 #include <string.h>
  31 #include <sys/types.h>
  32 #include <stdio.h>
  33 #include <glib.h>
  34 #include <glib/gi18n.h>
  35 #include <errno.h>
  36 #ifdef G_OS_WIN32
  37 #  include <winsock2.h>
  38 #else
  39 #  include <sys/socket.h>
  40 #  include <netinet/in.h>
  41 #  include <netdb.h>
  42 #endif /* G_OS_WIN32 */
  43 #include "ssl_certificate.h"
  44 #include "utils.h"
  45 #include "log.h"
  46 #include "socket.h"
  47 #include "hooks.h"
  48 #include "defs.h"
  49 #include "file-utils.h"
  50
  51 static GHashTable *warned_expired = NULL;
  52
  53 gboolean prefs_common_unsafe_ssl_certs(void);
  54
  55 static gchar *get_certificate_path(const gchar *host, const gchar *port, const gchar *fp)
  56 {
  57         gchar *ret;
  58         gchar *filename;
  59
  60         if (fp != NULL && prefs_common_unsafe_ssl_certs()) {
  61                 filename = g_strconcat(host, ".", port, ".", fp, ".cert", NULL);
  62         } else {
  63                 filename = g_strconcat(host, ".", port, ".cert", NULL);
  64         }
  65         subst_for_filename(filename);
  66
  67         ret = g_strconcat(get_rc_dir(), G_DIR_SEPARATOR_S,
  68                   "certs", G_DIR_SEPARATOR_S,
  69                   filename, NULL);
  70
  71         g_free(filename);
  72         return ret;
  73 }
  74
  75 static gchar *get_certificate_chain_path(const gchar *host, const gchar *port, const gchar *fp)
  76 {
  77         gchar *tmp = get_certificate_path(host, port, fp);
  78         gchar *result = g_strconcat(tmp, ".chain", NULL);
  79
  80         g_free(tmp);
  81
  82         return result;
  83 }
  84
  85 char * readable_fingerprint(unsigned char *src, int len)
  86 {
  87         int i=0;
  88         char * ret;
  89
  90         if (src == NULL)
  91                 return NULL;
  92         ret = g_strdup("");
  93         while (i < len) {
  94                 char *tmp2;
  95                 if(i>0)
  96                         tmp2 = g_strdup_printf("%s:%02X", ret, src[i]);
  97                 else
  98                         tmp2 = g_strdup_printf("%02X", src[i]);
  99                 g_free(ret);
 100                 ret = g_strdup(tmp2);
 101                 g_free(tmp2);
 102                 i++;
 103         }
 104         return ret;
 105 }
 106
 107 #if USE_GNUTLS
 108 static gnutls_x509_crt_t x509_crt_copy(gnutls_x509_crt_t src)
 109 {
 110     int ret;
 111     size_t size;
 112     gnutls_datum_t tmp;
 113     gnutls_x509_crt_t dest;
 114     size = 0;
 115
 116     if (gnutls_x509_crt_init(&dest) != 0) {
 117         g_warning("couldn't gnutls_x509_crt_init");
 118         return NULL;
 119     }
 120
 121     if (gnutls_x509_crt_export(src, GNUTLS_X509_FMT_DER, NULL, &size)
 122         != GNUTLS_E_SHORT_MEMORY_BUFFER) {
 123         g_warning("couldn't gnutls_x509_crt_export to get size");
 124         gnutls_x509_crt_deinit(dest);
 125         return NULL;
 126     }
 127
 128     tmp.data = malloc(size);
 129     memset(tmp.data, 0, size);
 130     ret = gnutls_x509_crt_export(src, GNUTLS_X509_FMT_DER, tmp.data, &size);
 131     if (ret == 0) {
 132         tmp.size = size;
 133         ret = gnutls_x509_crt_import(dest, &tmp, GNUTLS_X509_FMT_DER);
 134         if (ret) {
 135                 g_warning("couldn't gnutls_x509_crt_import for real (%d %s)", ret, gnutls_strerror(ret));
 136                 gnutls_x509_crt_deinit(dest);
 137                 dest = NULL;
 138         }
 139     } else {
 140         g_warning("couldn't gnutls_x509_crt_export for real (%d %s)", ret, gnutls_strerror(ret));
 141         gnutls_x509_crt_deinit(dest);
 142         dest = NULL;
 143     }
 144
 145     free(tmp.data);
 146     return dest;
 147 }
 148 #endif
 149
 150 static SSLCertificate *ssl_certificate_new(gnutls_x509_crt_t x509_cert, const gchar *host, gushort port)
 151 {
 152         SSLCertificate *cert = g_new0(SSLCertificate, 1);
 153         size_t n;
 154         unsigned char md[128];
 155
 156         if (host == NULL || x509_cert == NULL) {
 157                 ssl_certificate_destroy(cert);
 158                 return NULL;
 159         }
 160         cert->x509_cert = x509_crt_copy(x509_cert);
 161         cert->status = (guint)-1;
 162         cert->host = g_strdup(host);
 163         cert->port = port;
 164
 165         /* fingerprint */
 166         n = sizeof(md);
 167         gnutls_x509_crt_get_fingerprint(cert->x509_cert, GNUTLS_DIG_MD5, md, &n);
 168         cert->fingerprint = readable_fingerprint(md, (int)n);
 169         return cert;
 170 }
 171
 172 static void gnutls_export_X509_fp(FILE *fp, gnutls_x509_crt_t x509_cert, gnutls_x509_crt_fmt_t format)
 173 {
 174         char output[10*1024];
 175         size_t cert_size = 10*1024;
 176         int r;
 177
 178         if ((r = gnutls_x509_crt_export(x509_cert, format, output, &cert_size)) < 0) {
 179                 g_warning("couldn't export cert %s (%"G_GSIZE_FORMAT")", gnutls_strerror(r), cert_size);
 180                 return;
 181         }
 182         debug_print("writing %" G_GSIZE_FORMAT " bytes\n",cert_size);
 183         if (claws_fwrite(&output, 1, cert_size, fp) < cert_size) {
 184                 g_warning("failed to write cert: %d %s", errno, g_strerror(errno));
 185         }
 186 }
 187
 188 size_t gnutls_i2d_X509(gnutls_x509_crt_t x509_cert, unsigned char **output)
 189 {
 190         size_t cert_size = 10*1024;
 191         int r;
 192
 193         if (output == NULL)
 194                 return 0;
 195
 196         *output = malloc(cert_size);
 197
 198         if ((r = gnutls_x509_crt_export(x509_cert, GNUTLS_X509_FMT_DER, *output, &cert_size)) < 0) {
 199                 g_warning("couldn't export cert %s (%"G_GSIZE_FORMAT")", gnutls_strerror(r), cert_size);
 200                 free(*output);
 201                 *output = NULL;
 202                 return 0;
 203         }
 204         return cert_size;
 205 }
 206
 207 size_t gnutls_i2d_PrivateKey(gnutls_x509_privkey_t pkey, unsigned char **output)
 208 {
 209         size_t key_size = 10*1024;
 210         int r;
 211
 212         if (output == NULL)
 213                 return 0;
 214
 215         *output = malloc(key_size);
 216
 217         if ((r = gnutls_x509_privkey_export(pkey, GNUTLS_X509_FMT_DER, *output, &key_size)) < 0) {
 218                 g_warning("couldn't export key %s (%"G_GSIZE_FORMAT")", gnutls_strerror(r), key_size);
 219                 free(*output);
 220                 *output = NULL;
 221                 return 0;
 222         }
 223         return key_size;
 224 }
 225
 226 static int gnutls_import_X509_list_fp(FILE *fp, gnutls_x509_crt_fmt_t format,
 227                                    gnutls_x509_crt_t **cert_list, gint *num_certs)
 228 {
 229         gnutls_x509_crt_t *crt_list;
 230         unsigned int max = 512;
 231         unsigned int flags = 0;
 232         gnutls_datum_t tmp;
 233         struct stat s;
 234         int r;
 235
 236         *cert_list = NULL;
 237         *num_certs = 0;
 238
 239         if (fp == NULL)
 240                 return -ENOENT;
 241
 242         if (fstat(fileno(fp), &s) < 0) {
 243                 perror("fstat");
 244                 return -errno;
 245         }
 246
 247         crt_list=(gnutls_x509_crt_t*)malloc(max*sizeof(gnutls_x509_crt_t));
 248         tmp.data = malloc(s.st_size);
 249         memset(tmp.data, 0, s.st_size);
 250         tmp.size = s.st_size;
 251         if (claws_fread (tmp.data, 1, s.st_size, fp) < s.st_size) {
 252                 perror("claws_fread");
 253                 free(tmp.data);
 254                 free(crt_list);
 255                 return -EIO;
 256         }
 257
 258         if ((r = gnutls_x509_crt_list_import(crt_list, &max,
 259                         &tmp, format, flags)) < 0) {
 260                 debug_print("cert import failed: %s\n", gnutls_strerror(r));
 261                 free(tmp.data);
 262                 free(crt_list);
 263                 return r;
 264         }
 265         free(tmp.data);
 266         debug_print("got %d certs in crt_list! %p\n", max, &crt_list);
 267
 268         *cert_list = crt_list;
 269         *num_certs = max;
 270
 271         return r;
 272 }
 273
 274 /* return one certificate, read from file */
 275 static gnutls_x509_crt_t gnutls_import_X509_fp(FILE *fp, gnutls_x509_crt_fmt_t format)
 276 {
 277         gnutls_x509_crt_t *certs = NULL;
 278         gnutls_x509_crt_t cert = NULL;
 279         int i, ncerts, r;
 280
 281         if ((r = gnutls_import_X509_list_fp(fp, format, &certs, &ncerts)) < 0) {
 282                 return NULL;
 283         }
 284
 285         if (ncerts == 0)
 286                 return NULL;
 287
 288         for (i = 1; i < ncerts; i++)
 289                 gnutls_x509_crt_deinit(certs[i]);
 290
 291         cert = certs[0];
 292         free(certs);
 293
 294         return cert;
 295 }
 296
 297 static gnutls_x509_privkey_t gnutls_import_key_fp(FILE *fp, gnutls_x509_crt_fmt_t format)
 298 {
 299         gnutls_x509_privkey_t key = NULL;
 300         gnutls_datum_t tmp;
 301         struct stat s;
 302         int r;
 303         if (fstat(fileno(fp), &s) < 0) {
 304                 perror("fstat");
 305                 return NULL;
 306         }
 307         tmp.data = malloc(s.st_size);
 308         memset(tmp.data, 0, s.st_size);
 309         tmp.size = s.st_size;
 310         if (claws_fread (tmp.data, 1, s.st_size, fp) < s.st_size) {
 311                 perror("claws_fread");
 312                 free(tmp.data);
 313                 return NULL;
 314         }
 315
 316         gnutls_x509_privkey_init(&key);
 317         if ((r = gnutls_x509_privkey_import(key, &tmp, format)) < 0) {
 318                 debug_print("key import failed: %s\n", gnutls_strerror(r));
 319                 gnutls_x509_privkey_deinit(key);
 320                 key = NULL;
 321         }
 322         free(tmp.data);
 323         debug_print("got key! %p\n", key);
 324         return key;
 325 }
 326
 327 static gnutls_pkcs12_t gnutls_import_PKCS12_fp(FILE *fp, gnutls_x509_crt_fmt_t format)
 328 {
 329         gnutls_pkcs12_t p12 = NULL;
 330         gnutls_datum_t tmp;
 331         struct stat s;
 332         int r;
 333         if (fstat(fileno(fp), &s) < 0) {
 334                 log_error(LOG_PROTOCOL, _("Cannot stat P12 certificate file (%s)\n"),
 335                                   g_strerror(errno));
 336                 return NULL;
 337         }
 338         tmp.data = malloc(s.st_size);
 339         memset(tmp.data, 0, s.st_size);
 340         tmp.size = s.st_size;
 341         if (claws_fread (tmp.data, 1, s.st_size, fp) < s.st_size) {
 342                 log_error(LOG_PROTOCOL, _("Cannot read P12 certificate file (%s)\n"),
 343                                   g_strerror(errno));
 344                 free(tmp.data);
 345                 return NULL;
 346         }
 347
 348         gnutls_pkcs12_init(&p12);
 349
 350         if ((r = gnutls_pkcs12_import(p12, &tmp, format, 0)) < 0) {
 351                 log_error(LOG_PROTOCOL, _("Cannot import P12 certificate file (%s)\n"),
 352                                   gnutls_strerror(r));
 353                 gnutls_pkcs12_deinit(p12);
 354                 p12 = NULL;
 355         }
 356         free(tmp.data);
 357         debug_print("got p12! %p\n", p12);
 358         return p12;
 359 }
 360
 361 static void ssl_certificate_save (SSLCertificate *cert)
 362 {
 363         gchar *file, *port;
 364         FILE *fp;
 365
 366         file = g_strconcat(get_rc_dir(), G_DIR_SEPARATOR_S,
 367                           "certs", G_DIR_SEPARATOR_S, NULL);
 368
 369         if (!is_dir_exist(file))
 370                 make_dir_hier(file);
 371         g_free(file);
 372
 373         port = g_strdup_printf("%d", cert->port);
 374         file = get_certificate_path(cert->host, port, cert->fingerprint);
 375
 376         g_free(port);
 377         fp = claws_fopen(file, "wb");
 378         if (fp == NULL) {
 379                 g_free(file);
 380                 debug_print("Can't save certificate !\n");
 381                 return;
 382         }
 383
 384         gnutls_export_X509_fp(fp, cert->x509_cert, GNUTLS_X509_FMT_DER);
 385
 386         g_free(file);
 387         claws_safe_fclose(fp);
 388
 389 }
 390
 391 void ssl_certificate_destroy(SSLCertificate *cert)
 392 {
 393         if (cert == NULL)
 394                 return;
 395
 396         if (cert->x509_cert)
 397                 gnutls_x509_crt_deinit(cert->x509_cert);
 398         g_free(cert->host);
 399         g_free(cert->fingerprint);
 400         g_free(cert);
 401         cert = NULL;
 402 }
 403
 404 void ssl_certificate_delete_from_disk(SSLCertificate *cert)
 405 {
 406         gchar *buf;
 407         gchar *file;
 408         buf = g_strdup_printf("%d", cert->port);
 409         file = get_certificate_path(cert->host, buf, cert->fingerprint);
 410         claws_unlink (file);
 411         g_free(file);
 412         file = get_certificate_chain_path(cert->host, buf, cert->fingerprint);
 413         claws_unlink (file);
 414         g_free(file);
 415         g_free(buf);
 416 }
 417
 418 SSLCertificate *ssl_certificate_find (const gchar *host, gushort port, const gchar *fingerprint)
 419 {
 420         gchar *file = NULL;
 421         gchar *buf;
 422         SSLCertificate *cert = NULL;
 423         gnutls_x509_crt_t tmp_x509;
 424         FILE *fp = NULL;
 425         gboolean must_rename = FALSE;
 426
 427         buf = g_strdup_printf("%d", port);
 428
 429         if (fingerprint != NULL) {
 430                 file = get_certificate_path(host, buf, fingerprint);
 431                 fp = claws_fopen(file, "rb");
 432         }
 433         if (fp == NULL) {
 434                 /* see if we have the old one */
 435                 debug_print("didn't get %s\n", file);
 436                 g_free(file);
 437                 file = get_certificate_path(host, buf, NULL);
 438                 fp = claws_fopen(file, "rb");
 439
 440                 if (fp) {
 441                         debug_print("got %s\n", file);
 442                         must_rename = (fingerprint != NULL);
 443                 }
 444         } else {
 445                 debug_print("got %s first try\n", file);
 446         }
 447         if (fp == NULL) {
 448                 g_free(file);
 449                 g_free(buf);
 450                 return NULL;
 451         }
 452
 453         if ((tmp_x509 = gnutls_import_X509_fp(fp, GNUTLS_X509_FMT_DER)) != NULL) {
 454                 cert = ssl_certificate_new(tmp_x509, host, port);
 455                 debug_print("got cert %p\n", cert);
 456                 gnutls_x509_crt_deinit(tmp_x509);
 457         }
 458
 459         claws_fclose(fp);
 460         g_free(file);
 461
 462         if (must_rename) {
 463                 gchar *old = get_certificate_path(host, buf, NULL);
 464                 gchar *new = get_certificate_path(host, buf, fingerprint);
 465                 if (strcmp(old, new))
 466                         move_file(old, new, TRUE);
 467                 g_free(old);
 468                 g_free(new);
 469         }
 470         g_free(buf);
 471
 472         return cert;
 473 }
 474
 475 static gboolean ssl_certificate_compare (SSLCertificate *cert_a, SSLCertificate *cert_b)
 476 {
 477         char *output_a;
 478         char *output_b;
 479         size_t cert_size_a = 0, cert_size_b = 0;
 480         int r;
 481
 482         if (cert_a == NULL || cert_b == NULL)
 483                 return FALSE;
 484
 485         if ((r = gnutls_x509_crt_export(cert_a->x509_cert, GNUTLS_X509_FMT_DER, NULL, &cert_size_a))
 486             != GNUTLS_E_SHORT_MEMORY_BUFFER) {
 487                 g_warning("couldn't gnutls_x509_crt_export to get size a %s", gnutls_strerror(r));
 488                 return FALSE;
 489         }
 490
 491         if ((r = gnutls_x509_crt_export(cert_b->x509_cert, GNUTLS_X509_FMT_DER, NULL, &cert_size_b))
 492             != GNUTLS_E_SHORT_MEMORY_BUFFER) {
 493                 g_warning("couldn't gnutls_x509_crt_export to get size b %s", gnutls_strerror(r));
 494                 return FALSE;
 495         }
 496
 497         if (cert_size_a != cert_size_b) {
 498                 debug_print("sizes differ: %"G_GSIZE_FORMAT" != %"G_GSIZE_FORMAT"\n", cert_size_a, cert_size_b);
 499                 return FALSE;
 500         }
 501
 502         output_a = g_malloc(cert_size_a);
 503         output_b = g_malloc(cert_size_b);
 504         if ((r = gnutls_x509_crt_export(cert_a->x509_cert, GNUTLS_X509_FMT_DER, output_a, &cert_size_a)) < 0) {
 505                 g_warning("couldn't gnutls_x509_crt_export a %s", gnutls_strerror(r));
 506                 g_free(output_a);
 507                 g_free(output_b);
 508                 return FALSE;
 509         }
 510         if ((r = gnutls_x509_crt_export(cert_b->x509_cert, GNUTLS_X509_FMT_DER, output_b, &cert_size_b)) < 0) {
 511                 g_warning("couldn't gnutls_x509_crt_export b %s", gnutls_strerror(r));
 512                 g_free(output_a);
 513                 g_free(output_b);
 514                 return FALSE;
 515         }
 516         if (memcmp(output_a, output_b, cert_size_a)) {
 517                 debug_print("contents differ\n");
 518                 g_free(output_a);
 519                 g_free(output_b);
 520                 return FALSE;
 521         }
 522         g_free(output_a);
 523         g_free(output_b);
 524
 525         return TRUE;
 526 }
 527
 528 static guint check_cert(SSLCertificate *cert)
 529 {
 530         gnutls_x509_crt_t *ca_list = NULL;
 531         gnutls_x509_crt_t *chain = NULL;
 532         unsigned int max_ca = 512, max_certs;
 533         unsigned int flags = 0;
 534         int r, i;
 535         unsigned int status;
 536         gchar *chain_file = NULL, *buf = NULL;
 537         FILE *fp;
 538
 539         if (claws_ssl_get_cert_file())
 540                 fp = claws_fopen(claws_ssl_get_cert_file(), "r");
 541         else
 542                 return (guint)-1;
 543
 544         if (fp == NULL)
 545                 return (guint)-1;
 546
 547         if ((r = gnutls_import_X509_list_fp(fp, GNUTLS_X509_FMT_PEM, &ca_list, &max_ca)) < 0) {
 548                 debug_print("CA import failed: %s\n", gnutls_strerror(r));
 549                 claws_fclose(fp);
 550                 return (guint)-1;
 551         }
 552         claws_fclose(fp);
 553         fp = NULL;
 554
 555         buf = g_strdup_printf("%d", cert->port);
 556         chain_file = get_certificate_chain_path(cert->host, buf, cert->fingerprint);
 557         g_free(buf);
 558         if (is_file_exist(chain_file)) {
 559                 unsigned char md[128];
 560                 size_t n = 128;
 561                 char *fingerprint;
 562
 563                 fp = claws_fopen(chain_file, "r");
 564                 if (fp == NULL) {
 565                         debug_print("claws_fopen %s failed: %s\n", chain_file, g_strerror(errno));
 566                         g_free(chain_file);
 567                         return (guint)-1;
 568                 }
 569                 if ((r = gnutls_import_X509_list_fp(fp, GNUTLS_X509_FMT_PEM, &chain, &max_certs)) < 0) {
 570                         debug_print("chain import failed: %s\n", gnutls_strerror(r));
 571                         claws_fclose(fp);
 572                         g_free(chain_file);
 573                         return (guint)-1;
 574                 }
 575                 g_free(chain_file);
 576                 claws_fclose(fp);
 577                 fp = NULL;
 578
 579                 gnutls_x509_crt_get_fingerprint(chain[0], GNUTLS_DIG_MD5, md, &n);
 580                 fingerprint = readable_fingerprint(md, n);
 581                 if (!fingerprint || strcmp(fingerprint, cert->fingerprint)) {
 582                         debug_print("saved chain fingerprint does not match current : %s / %s\n",
 583                                 cert->fingerprint, fingerprint);
 584
 585                         return (guint)-1;
 586                 }
 587                 g_free(fingerprint);
 588
 589                 r = gnutls_x509_crt_list_verify (chain,
 590                                      max_certs,
 591                                      ca_list, max_ca,
 592                                      NULL, 0,
 593                                      GNUTLS_VERIFY_ALLOW_X509_V1_CA_CRT,
 594                                      &status);
 595                 if (r < 0)
 596                         debug_print("chain check failed: %s\n", gnutls_strerror(r));
 597
 598                 for (i = 0; i < max_certs; i++)
 599                         gnutls_x509_crt_deinit(chain[i]);
 600                 free(chain);
 601
 602         } else {
 603                 r = gnutls_x509_crt_verify(cert->x509_cert, ca_list, max_ca, flags, &status);
 604                 if (r < 0)
 605                         debug_print("cert check failed: %s\n", gnutls_strerror(r));
 606         }
 607
 608         for (i = 0; i < max_ca; i++)
 609                 gnutls_x509_crt_deinit(ca_list[i]);
 610         free(ca_list);
 611
 612         if (r < 0)
 613                 return (guint)-1;
 614         else
 615                 return status;
 616
 617 }
 618
 619 static gboolean ssl_certificate_is_valid(SSLCertificate *cert, guint status)
 620 {
 621         gchar *str_status = ssl_certificate_check_signer(cert, status);
 622
 623         if (str_status != NULL) {
 624                 g_free(str_status);
 625                 return FALSE;
 626         }
 627         return ssl_certificate_check_subject_cn(cert);
 628 }
 629
 630 char *ssl_certificate_check_signer (SSLCertificate *cert, guint status)
 631 {
 632         gnutls_x509_crt_t x509_cert = cert ? cert->x509_cert : NULL;
 633
 634         if (!cert)
 635                 return g_strdup(_("Internal error"));
 636
 637         if (status == (guint)-1) {
 638                 status = check_cert(cert);
 639                 if (status == -1)
 640                         return g_strdup(_("Uncheckable"));
 641         }
 642         if (status & GNUTLS_CERT_INVALID) {
 643                 if (gnutls_x509_crt_check_issuer(x509_cert, x509_cert))
 644                         return g_strdup(_("Self-signed certificate"));
 645         }
 646         if (status & GNUTLS_CERT_REVOKED)
 647                 return g_strdup(_("Revoked certificate"));
 648         if (status & GNUTLS_CERT_SIGNER_NOT_FOUND)
 649                 return g_strdup(_("No certificate issuer found"));
 650         if (status & GNUTLS_CERT_SIGNER_NOT_CA)
 651                 return g_strdup(_("Certificate issuer is not a CA"));
 652
 653
 654         return NULL;
 655 }
 656
 657 static void ssl_certificate_save_chain(gnutls_x509_crt_t *certs, gint len, const gchar *host, gushort port)
 658 {
 659         gint i;
 660         gchar *file = NULL;
 661         FILE *fp = NULL;
 662
 663         for (i = 0; i < len; i++) {
 664                 size_t n;
 665                 unsigned char md[128];
 666                 gnutls_x509_crt_t cert = certs[i];
 667
 668                 if (i == 0) {
 669                         n = sizeof(md);
 670                         gnutls_x509_crt_get_fingerprint(cert, GNUTLS_DIG_MD5, md, &n);
 671                         gchar *fingerprint = readable_fingerprint(md, n);
 672                         gchar *buf = g_strdup_printf("%d", port);
 673
 674                         file = get_certificate_chain_path(host, buf, fingerprint);
 675                         g_free(fingerprint);
 676
 677                         g_free(buf);
 678
 679                         fp = claws_fopen(file, "wb");
 680                         if (fp == NULL) {
 681                                 g_free(file);
 682                                 debug_print("Can't save certificate !\n");
 683                                 return;
 684                         }
 685                         g_free(file);
 686                 }
 687
 688                 gnutls_export_X509_fp(fp, cert, GNUTLS_X509_FMT_PEM);
 689
 690         }
 691         if (fp)
 692                 claws_safe_fclose(fp);
 693 }
 694
 695 gboolean ssl_certificate_check (gnutls_x509_crt_t x509_cert, guint status,
 696                                 const gchar *host, gushort port,
 697                                 gboolean accept_if_valid)
 698 {
 699         SSLCertificate *current_cert = NULL;
 700         SSLCertificate *known_cert;
 701         SSLCertHookData cert_hook_data;
 702         gchar *fingerprint;
 703         size_t n;
 704         unsigned char md[128];
 705         gboolean valid = FALSE;
 706
 707         current_cert = ssl_certificate_new(x509_cert, host, port);
 708
 709         if (current_cert == NULL) {
 710                 debug_print("Buggy certificate !\n");
 711                 return FALSE;
 712         }
 713
 714         current_cert->status = status;
 715         /* fingerprint */
 716         n = sizeof(md);
 717         gnutls_x509_crt_get_fingerprint(x509_cert, GNUTLS_DIG_MD5, md, &n);
 718         fingerprint = readable_fingerprint(md, n);
 719
 720         known_cert = ssl_certificate_find(host, port, fingerprint);
 721
 722         g_free(fingerprint);
 723
 724         if (accept_if_valid)
 725                 valid = ssl_certificate_is_valid(current_cert, status);
 726         else
 727                 valid = FALSE; /* Force check */
 728
 729         if (known_cert == NULL) {
 730                 if (valid) {
 731                         ssl_certificate_save(current_cert);
 732                         ssl_certificate_destroy(current_cert);
 733                         return TRUE;
 734                 }
 735
 736                 cert_hook_data.cert = current_cert;
 737                 cert_hook_data.old_cert = NULL;
 738                 cert_hook_data.expired = FALSE;
 739                 cert_hook_data.accept = FALSE;
 740
 741                 hooks_invoke(SSLCERT_ASK_HOOKLIST, &cert_hook_data);
 742
 743                 if (!cert_hook_data.accept) {
 744                         ssl_certificate_destroy(current_cert);
 745                         return FALSE;
 746                 } else {
 747                         ssl_certificate_save(current_cert);
 748                         ssl_certificate_destroy(current_cert);
 749                         return TRUE;
 750                 }
 751         } else if (!ssl_certificate_compare (current_cert, known_cert)) {
 752                 if (valid) {
 753                         ssl_certificate_save(current_cert);
 754                         ssl_certificate_destroy(current_cert);
 755                         ssl_certificate_destroy(known_cert);
 756                         return TRUE;
 757                 }
 758
 759                 cert_hook_data.cert = current_cert;
 760                 cert_hook_data.old_cert = known_cert;
 761                 cert_hook_data.expired = FALSE;
 762                 cert_hook_data.accept = FALSE;
 763
 764                 hooks_invoke(SSLCERT_ASK_HOOKLIST, &cert_hook_data);
 765
 766                 if (!cert_hook_data.accept) {
 767                         ssl_certificate_destroy(current_cert);
 768                         ssl_certificate_destroy(known_cert);
 769                         return FALSE;
 770                 } else {
 771                         ssl_certificate_save(current_cert);
 772                         ssl_certificate_destroy(current_cert);
 773                         ssl_certificate_destroy(known_cert);
 774                         return TRUE;
 775                 }
 776         } else if (gnutls_x509_crt_get_expiration_time(current_cert->x509_cert) < time(NULL)) {
 777                 gchar *tmp = g_strdup_printf("%s:%d", current_cert->host, current_cert->port);
 778
 779                 if (warned_expired == NULL)
 780                         warned_expired = g_hash_table_new(g_str_hash, g_str_equal);
 781
 782                 if (g_hash_table_lookup(warned_expired, tmp)) {
 783                         g_free(tmp);
 784                         ssl_certificate_destroy(current_cert);
 785                         ssl_certificate_destroy(known_cert);
 786                         return TRUE;
 787                 }
 788
 789                 cert_hook_data.cert = current_cert;
 790                 cert_hook_data.old_cert = NULL;
 791                 cert_hook_data.expired = TRUE;
 792                 cert_hook_data.accept = FALSE;
 793
 794                 hooks_invoke(SSLCERT_ASK_HOOKLIST, &cert_hook_data);
 795
 796                 if (!cert_hook_data.accept) {
 797                         g_free(tmp);
 798                         ssl_certificate_destroy(current_cert);
 799                         ssl_certificate_destroy(known_cert);
 800                         return FALSE;
 801                 } else {
 802                         g_hash_table_insert(warned_expired, tmp, GINT_TO_POINTER(1));
 803                         ssl_certificate_destroy(current_cert);
 804                         ssl_certificate_destroy(known_cert);
 805                         return TRUE;
 806                 }
 807         }
 808
 809         ssl_certificate_destroy(current_cert);
 810         ssl_certificate_destroy(known_cert);
 811         return TRUE;
 812 }
 813
 814 gboolean ssl_certificate_check_chain(gnutls_x509_crt_t *certs, gint chain_len,
 815                                      const gchar *host, gushort port,
 816                                      gboolean accept_if_valid)
 817 {
 818         int ncas = 0;
 819         gnutls_x509_crt_t *cas = NULL;
 820         gboolean result = FALSE;
 821         int i;
 822         gint status;
 823
 824         if (claws_ssl_get_cert_file()) {
 825                 FILE *fp = claws_fopen(claws_ssl_get_cert_file(), "rb");
 826                 int r = -errno;
 827
 828                 if (fp) {
 829                         r = gnutls_import_X509_list_fp(fp, GNUTLS_X509_FMT_PEM, &cas, &ncas);
 830                         claws_fclose(fp);
 831                 }
 832
 833                 if (r < 0)
 834                         g_warning("can't read SSL_CERT_FILE '%s': %s",
 835                                 claws_ssl_get_cert_file(),
 836                                 gnutls_strerror(r));
 837         } else {
 838                 debug_print("Can't find SSL ca-certificates file\n");
 839         }
 840
 841
 842         gnutls_x509_crt_list_verify (certs,
 843                              chain_len,
 844                              cas, ncas,
 845                              NULL, 0,
 846                              GNUTLS_VERIFY_ALLOW_X509_V1_CA_CRT,
 847                              &status);
 848
 849         result = ssl_certificate_check(certs[0], status, host, port,
 850                                         accept_if_valid);
 851
 852         if (result == TRUE) {
 853                 ssl_certificate_save_chain(certs, chain_len, host, port);
 854         }
 855
 856         for (i = 0; i < ncas; i++)
 857                 gnutls_x509_crt_deinit(cas[i]);
 858         free(cas);
 859
 860         return result;
 861 }
 862
 863 gnutls_x509_crt_t ssl_certificate_get_x509_from_pem_file(const gchar *file)
 864 {
 865         gnutls_x509_crt_t x509 = NULL;
 866         if (!file)
 867                 return NULL;
 868
 869         if (is_file_exist(file)) {
 870                 FILE *fp = claws_fopen(file, "r");
 871                 if (fp) {
 872                         x509 = gnutls_import_X509_fp(fp, GNUTLS_X509_FMT_PEM);
 873                         claws_fclose(fp);
 874                         return x509;
 875                 } else {
 876                         log_error(LOG_PROTOCOL, _("Cannot open certificate file %s: %s\n"),
 877                                   file, g_strerror(errno));
 878                 }
 879         } else {
 880                 log_error(LOG_PROTOCOL, _("Certificate file %s missing (%s)\n"),
 881                           file, g_strerror(errno));
 882         }
 883         return NULL;
 884 }
 885
 886 gnutls_x509_privkey_t ssl_certificate_get_pkey_from_pem_file(const gchar *file)
 887 {
 888         gnutls_x509_privkey_t key = NULL;
 889         if (!file)
 890                 return NULL;
 891
 892         if (is_file_exist(file)) {
 893                 FILE *fp = claws_fopen(file, "r");
 894                 if (fp) {
 895                         key = gnutls_import_key_fp(fp, GNUTLS_X509_FMT_PEM);
 896                         claws_fclose(fp);
 897                         return key;
 898                 } else {
 899                         log_error(LOG_PROTOCOL, _("Cannot open key file %s (%s)\n"),
 900                         file, g_strerror(errno));
 901                 }
 902         } else {
 903                 log_error(LOG_PROTOCOL, _("Key file %s missing (%s)\n"), file,
 904                           g_strerror(errno));
 905         }
 906         return NULL;
 907 }
 908
 909 /* From GnuTLS lib/gnutls_x509.c */
 910 static int
 911 parse_pkcs12 (gnutls_pkcs12_t p12,
 912               const char *password,
 913               gnutls_x509_privkey_t * key,
 914               gnutls_x509_crt_t * cert)
 915 {
 916   gnutls_pkcs12_bag_t bag = NULL;
 917   int index = 0;
 918   int ret;
 919
 920   for (;;)
 921     {
 922       int elements_in_bag;
 923       int i;
 924
 925       ret = gnutls_pkcs12_bag_init (&bag);
 926       if (ret < 0)
 927         {
 928           bag = NULL;
 929           goto done;
 930         }
 931
 932       ret = gnutls_pkcs12_get_bag (p12, index, bag);
 933       if (ret == GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE)
 934         break;
 935       if (ret < 0)
 936         {
 937           goto done;
 938         }
 939
 940       ret = gnutls_pkcs12_bag_get_type (bag, 0);
 941       if (ret < 0)
 942         {
 943           goto done;
 944         }
 945
 946       if (ret == GNUTLS_BAG_ENCRYPTED)
 947         {
 948           ret = gnutls_pkcs12_bag_decrypt (bag, password);
 949           if (ret < 0)
 950             {
 951               goto done;
 952             }
 953         }
 954
 955       elements_in_bag = gnutls_pkcs12_bag_get_count (bag);
 956       if (elements_in_bag < 0)
 957         {
 958           goto done;
 959         }
 960
 961       for (i = 0; i < elements_in_bag; i++)
 962         {
 963           int type;
 964           gnutls_datum_t data;
 965
 966           type = gnutls_pkcs12_bag_get_type (bag, i);
 967           if (type < 0)
 968             {
 969               goto done;
 970             }
 971
 972           ret = gnutls_pkcs12_bag_get_data (bag, i, &data);
 973           if (ret < 0)
 974             {
 975               goto done;
 976             }
 977
 978           switch (type)
 979             {
 980             case GNUTLS_BAG_PKCS8_ENCRYPTED_KEY:
 981             case GNUTLS_BAG_PKCS8_KEY:
 982               ret = gnutls_x509_privkey_init (key);
 983               if (ret < 0)
 984                 {
 985                   goto done;
 986                 }
 987
 988               ret = gnutls_x509_privkey_import_pkcs8
 989                 (*key, &data, GNUTLS_X509_FMT_DER, password,
 990                  type == GNUTLS_BAG_PKCS8_KEY ? GNUTLS_PKCS_PLAIN : 0);
 991               if (ret < 0)
 992                 {
 993                   goto done;
 994                 }
 995               break;
 996
 997             case GNUTLS_BAG_CERTIFICATE:
 998               ret = gnutls_x509_crt_init (cert);
 999               if (ret < 0)
1000                 {
1001                   goto done;
1002                 }
1003
1004               ret =
1005                 gnutls_x509_crt_import (*cert, &data, GNUTLS_X509_FMT_DER);
1006               if (ret < 0)
1007                 {
1008                   goto done;
1009                 }
1010               break;
1011
1012             case GNUTLS_BAG_ENCRYPTED:
1013               /* XXX Bother to recurse one level down?  Unlikely to
1014                  use the same password anyway. */
1015             case GNUTLS_BAG_EMPTY:
1016             default:
1017               break;
1018             }
1019         }
1020
1021       index++;
1022       gnutls_pkcs12_bag_deinit (bag);
1023     }
1024
1025   ret = 0;
1026
1027 done:
1028   if (bag)
1029     gnutls_pkcs12_bag_deinit (bag);
1030
1031   return ret;
1032 }
1033 void ssl_certificate_get_x509_and_pkey_from_p12_file(const gchar *file, const gchar *password,
1034                         gnutls_x509_crt_t *x509, gnutls_x509_privkey_t *pkey)
1035 {
1036         gnutls_pkcs12_t p12 = NULL;
1037
1038         int r;
1039
1040         *x509 = NULL;
1041         *pkey = NULL;
1042         if (!file)
1043                 return;
1044
1045         if (is_file_exist(file)) {
1046                 FILE *fp = claws_fopen(file, "r");
1047                 if (fp) {
1048                         p12 = gnutls_import_PKCS12_fp(fp, GNUTLS_X509_FMT_DER);
1049                         claws_fclose(fp);
1050                         if (!p12) {
1051                                 log_error(LOG_PROTOCOL, _("Failed to read P12 certificate file %s\n"), file);
1052                         }
1053                 } else {
1054                         log_error(LOG_PROTOCOL, _("Cannot open P12 certificate file %s (%s)\n"),
1055                                   file, g_strerror(errno));
1056                 }
1057         } else {
1058                 log_error(LOG_PROTOCOL, _("P12 Certificate file %s missing (%s)\n"), file,
1059                           g_strerror(errno));
1060         }
1061         if (p12 != NULL) {
1062                 if ((r = parse_pkcs12(p12, password, pkey, x509)) == 0) {
1063                         debug_print("got p12\n");
1064                 } else {
1065                         log_error(LOG_PROTOCOL, "%s\n", gnutls_strerror(r));
1066                 }
1067                 gnutls_pkcs12_deinit(p12);
1068         }
1069 }
1070
1071 gboolean ssl_certificate_check_subject_cn(SSLCertificate *cert)
1072 {
1073         return gnutls_x509_crt_check_hostname(cert->x509_cert, cert->host) != 0;
1074 }
1075
1076 gchar *ssl_certificate_get_subject_cn(SSLCertificate *cert)
1077 {
1078         gchar subject_cn[BUFFSIZE];
1079         size_t n = BUFFSIZE;
1080
1081         if(gnutls_x509_crt_get_dn_by_oid(cert->x509_cert,
1082                 GNUTLS_OID_X520_COMMON_NAME, 0, 0, subject_cn, &n))
1083                 return g_strdup(_("<not in certificate>"));
1084
1085         return g_strdup(subject_cn);
1086 }
1087
1088 #endif /* USE_GNUTLS */