src/common/ssl.c

   1 /*
   2  * Sylpheed -- a GTK+ based, lightweight, and fast e-mail client
   3  * Copyright (C) 1999-2012 Hiroyuki Yamamoto 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
  20 #ifdef HAVE_CONFIG_H
  21 #  include "config.h"
  22 #include "claws-features.h"
  23 #endif
  24
  25 #ifdef USE_GNUTLS
  26 #include "defs.h"
  27
  28 #include <stdlib.h>
  29 #include <glib.h>
  30 #include <glib/gi18n.h>
  31 #include <errno.h>
  32 #include <pthread.h>
  33
  34 #include "claws.h"
  35 #include "utils.h"
  36 #include "ssl.h"
  37 #include "ssl_certificate.h"
  38 #include "hooks.h"
  39
  40 #if GNUTLS_VERSION_NUMBER <= 0x020b00
  41 #include <gcrypt.h>
  42 GCRY_THREAD_OPTION_PTHREAD_IMPL;
  43 #endif
  44
  45 #ifdef HAVE_LIBETPAN
  46 #include <libetpan/mailstream_ssl.h>
  47 #endif
  48
  49 #ifdef USE_PTHREAD
  50 #include <pthread.h>
  51 #endif
  52
  53 #ifdef USE_PTHREAD
  54 typedef struct _thread_data {
  55         gnutls_session_t ssl;
  56         gboolean done;
  57 } thread_data;
  58 #endif
  59
  60 #if GNUTLS_VERSION_NUMBER <= 0x020c00
  61 static int gnutls_client_cert_cb(gnutls_session_t session,
  62                                const gnutls_datum_t *req_ca_rdn, int nreqs,
  63                                const gnutls_pk_algorithm_t *sign_algos,
  64                                int sign_algos_length, gnutls_retr_st *st)
  65 #else
  66 static int gnutls_cert_cb(gnutls_session_t session,
  67                                const gnutls_datum_t *req_ca_rdn, int nreqs,
  68                                const gnutls_pk_algorithm_t *sign_algos,
  69                                int sign_algos_length, gnutls_retr2_st *st)
  70 #endif
  71 {
  72         SSLClientCertHookData hookdata;
  73         SockInfo *sockinfo = (SockInfo *)gnutls_session_get_ptr(session);
  74         gnutls_certificate_type_t type = gnutls_certificate_type_get(session);
  75         gnutls_x509_crt_t crt;
  76         gnutls_x509_privkey_t key;
  77
  78         st->ncerts = 0;
  79
  80         hookdata.account = sockinfo->account;
  81         hookdata.cert_path = NULL;
  82         hookdata.password = NULL;
  83         hookdata.is_smtp = sockinfo->is_smtp;
  84         hooks_invoke(SSLCERT_GET_CLIENT_CERT_HOOKLIST, &hookdata);
  85
  86         if (hookdata.cert_path == NULL) {
  87                 g_free(hookdata.password);
  88                 return 0;
  89         }
  90
  91         sockinfo->client_crt = ssl_certificate_get_x509_from_pem_file(hookdata.cert_path);
  92         sockinfo->client_key = ssl_certificate_get_pkey_from_pem_file(hookdata.cert_path);
  93         if (!(sockinfo->client_crt && sockinfo->client_key)) {
  94                 /* try pkcs12 format */
  95                 ssl_certificate_get_x509_and_pkey_from_p12_file(hookdata.cert_path, hookdata.password,
  96                         &crt, &key);
  97                 sockinfo->client_crt = crt;
  98                 sockinfo->client_key = key;
  99         }
 100
 101         if (type == GNUTLS_CRT_X509 && sockinfo->client_crt && sockinfo->client_key) {
 102                 st->ncerts = 1;
 103 #if GNUTLS_VERSION_NUMBER <= 0x020c00
 104                 st->type = type;
 105 #else
 106                 st->key_type = type;
 107 #endif
 108                 st->cert.x509 = &(sockinfo->client_crt);
 109                 st->key.x509 = sockinfo->client_key;
 110                 st->deinit_all = 0;
 111                 g_free(hookdata.password);
 112                 return 0;
 113         }
 114         g_free(hookdata.password);
 115         return 0;
 116 }
 117
 118 const gchar *claws_ssl_get_cert_file(void)
 119 {
 120 #ifndef G_OS_WIN32
 121         const char *cert_files[]={
 122                 "/etc/pki/tls/certs/ca-bundle.crt",
 123                 "/etc/certs/ca-bundle.crt",
 124                 "/etc/ssl/ca-bundle.pem",
 125                 "/usr/share/ssl/certs/ca-bundle.crt",
 126                 "/etc/ssl/certs/ca-certificates.crt",
 127                 "/usr/local/ssl/certs/ca-bundle.crt",
 128                 "/etc/apache/ssl.crt/ca-bundle.crt",
 129                 "/usr/share/curl/curl-ca-bundle.crt",
 130                 "/usr/share/curl/curl-ca-bundle.crt",
 131                 "/usr/lib/ssl/cert.pem",
 132                 NULL};
 133         int i;
 134 #endif
 135
 136         /* We honor this environment variable on all platforms. */
 137         if (g_getenv("SSL_CERT_FILE"))
 138                 return g_getenv("SSL_CERT_FILE");
 139
 140 #ifndef G_OS_WIN32
 141         for (i = 0; cert_files[i]; i++) {
 142                 if (is_file_exist(cert_files[i]))
 143                         return cert_files[i];
 144         }
 145         return NULL;
 146 #else
 147         return w32_get_cert_file();
 148 #endif
 149 }
 150
 151 const gchar *claws_ssl_get_cert_dir(void)
 152 {
 153         const char *cert_dirs[]={
 154                 "/etc/pki/tls/certs",
 155                 "/etc/certs",
 156                 "/usr/share/ssl/certs",
 157                 "/etc/ssl/certs",
 158                 "/usr/local/ssl/certs",
 159                 "/etc/apache/ssl.crt",
 160                 "/usr/share/curl",
 161                 "/usr/lib/ssl/certs",
 162                 NULL};
 163         int i;
 164
 165         if (g_getenv("SSL_CERT_DIR"))
 166                 return g_getenv("SSL_CERT_DIR");
 167 #ifndef G_OS_WIN32
 168         for (i = 0; cert_dirs[i]; i++) {
 169                 if (is_dir_exist(cert_dirs[i]))
 170                         return cert_dirs[i];
 171         }
 172         return NULL;
 173 #else
 174         return NULL;
 175 #endif
 176 }
 177
 178 void ssl_init(void)
 179 {
 180 #if GNUTLS_VERSION_NUMBER <= 0x020b00
 181         gcry_control (GCRYCTL_SET_THREAD_CBS, &gcry_threads_pthread);
 182 #endif
 183 #ifdef HAVE_LIBETPAN
 184         mailstream_gnutls_init_not_required();
 185 #endif
 186         gnutls_global_init();
 187 }
 188
 189 void ssl_done(void)
 190 {
 191         gnutls_global_deinit();
 192 }
 193
 194 #ifdef USE_PTHREAD
 195 static void *SSL_connect_thread(void *data)
 196 {
 197         thread_data *td = (thread_data *)data;
 198         int result = -1;
 199
 200         pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, NULL);
 201         pthread_setcanceltype(PTHREAD_CANCEL_ASYNCHRONOUS, NULL);
 202
 203         do {
 204                 result = gnutls_handshake(td->ssl);
 205         } while (result == GNUTLS_E_AGAIN || result == GNUTLS_E_INTERRUPTED);
 206
 207         td->done = TRUE; /* let the caller thread join() */
 208         return GINT_TO_POINTER(result);
 209 }
 210 #endif
 211
 212 static gint SSL_connect_nb(gnutls_session_t ssl)
 213 {
 214         int result;
 215 #ifdef USE_PTHREAD
 216         thread_data *td = g_new0(thread_data, 1);
 217         pthread_t pt;
 218         pthread_attr_t pta;
 219         void *res = NULL;
 220         time_t start_time = time(NULL);
 221         gboolean killed = FALSE;
 222
 223         td->ssl  = ssl;
 224         td->done = FALSE;
 225
 226         /* try to create a thread to initialize the SSL connection,
 227          * fallback to blocking method in case of problem
 228          */
 229         if (pthread_attr_init(&pta) != 0 ||
 230             pthread_attr_setdetachstate(&pta, PTHREAD_CREATE_JOINABLE) != 0 ||
 231             pthread_create(&pt, &pta, SSL_connect_thread, td) != 0) {
 232                 do {
 233                         result = gnutls_handshake(td->ssl);
 234                 } while (result == GNUTLS_E_AGAIN || result == GNUTLS_E_INTERRUPTED);
 235                 return result;
 236         }
 237         debug_print("waiting for SSL_connect thread...\n");
 238         while(!td->done) {
 239                 /* don't let the interface freeze while waiting */
 240                 claws_do_idle();
 241                 if (time(NULL) - start_time > 30) {
 242                         pthread_cancel(pt);
 243                         td->done = TRUE;
 244                         killed = TRUE;
 245                 }
 246         }
 247
 248         /* get the thread's return value and clean its resources */
 249         pthread_join(pt, &res);
 250         g_free(td);
 251
 252         if (killed) {
 253                 res = GINT_TO_POINTER(-1);
 254         }
 255         debug_print("SSL_connect thread returned %d\n",
 256                         GPOINTER_TO_INT(res));
 257
 258         return GPOINTER_TO_INT(res);
 259 #else /* USE_PTHREAD */
 260         do {
 261                 result = gnutls_handshake(ssl);
 262         } while (result == GNUTLS_E_AGAIN || result == GNUTLS_E_INTERRUPTED);
 263 #endif
 264 }
 265
 266 gnutls_x509_crt_t *ssl_get_certificate_chain(gnutls_session_t session, gint *list_len)
 267 {
 268         const gnutls_datum_t *raw_cert_list;
 269         gnutls_x509_crt_t *certs = NULL;
 270         gboolean result = TRUE;
 271
 272         *list_len = -1;
 273         if (!session)
 274                 return NULL;
 275
 276         raw_cert_list = gnutls_certificate_get_peers(session, list_len);
 277
 278         if (raw_cert_list && gnutls_certificate_type_get(session) == GNUTLS_CRT_X509) {
 279                 int i = 0;
 280
 281                 if (*list_len > 128)
 282                         *list_len = 128;
 283
 284                 certs = g_malloc(sizeof(gnutls_x509_crt_t) * (*list_len));
 285
 286                 for(i = 0 ; i < (*list_len) ; i++) {
 287                         int r;
 288
 289                         gnutls_x509_crt_init(&certs[i]);
 290                         r = gnutls_x509_crt_import(certs[i], &raw_cert_list[i], GNUTLS_X509_FMT_DER);
 291                         if (r < 0) {
 292                                 g_warning("cert get failure: %d %s", r, gnutls_strerror(r));
 293
 294                                 result = FALSE;
 295                                 i--;
 296                                 break;
 297                         }
 298                 }
 299                 if (!result) {
 300                         for (; i >= 0; i--)
 301                                 gnutls_x509_crt_deinit(certs[i]);
 302
 303                         g_free(certs);
 304                         *list_len = -1;
 305
 306                         return NULL;
 307                 }
 308         }
 309
 310         return certs;
 311 }
 312
 313 gboolean ssl_init_socket(SockInfo *sockinfo)
 314 {
 315         gnutls_session_t session;
 316         int r, i;
 317         unsigned int cert_list_length;
 318         gnutls_x509_crt_t *certs = NULL;
 319         gnutls_certificate_credentials_t xcred;
 320
 321         if (gnutls_certificate_allocate_credentials (&xcred) != 0)
 322                 return FALSE;
 323
 324         r = gnutls_init(&session, GNUTLS_CLIENT);
 325         if (session == NULL || r != 0)
 326                 return FALSE;
 327
 328         if (sockinfo->gnutls_priority && strlen(sockinfo->gnutls_priority)) {
 329                 r = gnutls_priority_set_direct(session, sockinfo->gnutls_priority, NULL);
 330                 debug_print("Setting GnuTLS priority to %s, status = %d\n",
 331                             sockinfo->gnutls_priority, r);
 332         }
 333 #ifdef GNUTLS_VERSION_NUMBER < 0x030400
 334         else {
 335                 gnutls_priority_set_direct(session, "NORMAL:-VERS-SSL3.0", NULL);
 336         }
 337 #endif
 338         gnutls_record_disable_padding(session);
 339
 340         gnutls_credentials_set(session, GNUTLS_CRD_CERTIFICATE, xcred);
 341
 342         if (claws_ssl_get_cert_file()) {
 343                 r = gnutls_certificate_set_x509_trust_file(xcred, claws_ssl_get_cert_file(),  GNUTLS_X509_FMT_PEM);
 344                 if (r < 0)
 345                         g_warning("Can't read SSL_CERT_FILE '%s': %s",
 346                                 claws_ssl_get_cert_file(),
 347                                 gnutls_strerror(r));
 348         } else {
 349                 debug_print("Can't find SSL ca-certificates file\n");
 350         }
 351         gnutls_certificate_set_verify_flags (xcred, GNUTLS_VERIFY_ALLOW_X509_V1_CA_CRT);
 352
 353         gnutls_transport_set_ptr(session, (gnutls_transport_ptr_t) GINT_TO_POINTER(sockinfo->sock));
 354         gnutls_session_set_ptr(session, sockinfo);
 355 #if GNUTLS_VERSION_NUMBER <= 0x020c00
 356         gnutls_certificate_client_set_retrieve_function(xcred, gnutls_client_cert_cb);
 357 #else
 358         gnutls_certificate_set_retrieve_function(xcred, gnutls_cert_cb);
 359 #endif
 360
 361         gnutls_dh_set_prime_bits(session, 512);
 362
 363         if ((r = SSL_connect_nb(session)) < 0) {
 364                 g_warning("SSL connection failed (%s)", gnutls_strerror(r));
 365                 gnutls_certificate_free_credentials(xcred);
 366                 gnutls_deinit(session);
 367                 return FALSE;
 368         }
 369
 370         /* Get server's certificate (note: beware of dynamic allocation) */
 371         certs = ssl_get_certificate_chain(session, &cert_list_length);
 372
 373         if (!certs) {
 374                 gnutls_certificate_free_credentials(xcred);
 375                 gnutls_deinit(session);
 376                 return FALSE;
 377         }
 378
 379         if (!ssl_certificate_check_chain(certs, cert_list_length, sockinfo->hostname, sockinfo->port,
 380                                          sockinfo->ssl_cert_auto_accept)) {
 381                 for (i = 0; i < cert_list_length; i++)
 382                         gnutls_x509_crt_deinit(certs[i]);
 383                 g_free(certs);
 384                 gnutls_certificate_free_credentials(xcred);
 385                 gnutls_deinit(session);
 386                 return FALSE;
 387         }
 388
 389         for (i = 0; i < cert_list_length; i++)
 390                 gnutls_x509_crt_deinit(certs[i]);
 391         g_free(certs);
 392
 393         sockinfo->ssl = session;
 394         sockinfo->xcred = xcred;
 395         return TRUE;
 396 }
 397
 398 void ssl_done_socket(SockInfo *sockinfo)
 399 {
 400         if (sockinfo && sockinfo->ssl) {
 401                 if (sockinfo->xcred)
 402                         gnutls_certificate_free_credentials(sockinfo->xcred);
 403                 gnutls_deinit(sockinfo->ssl);
 404                 if (sockinfo->client_crt)
 405                         gnutls_x509_crt_deinit(sockinfo->client_crt);
 406                 if (sockinfo->client_key)
 407                         gnutls_x509_privkey_deinit(sockinfo->client_key);
 408                 sockinfo->client_key = NULL;
 409                 sockinfo->client_crt = NULL;
 410                 sockinfo->xcred = NULL;
 411                 sockinfo->ssl = NULL;
 412         }
 413 }
 414
 415 #endif /* USE_GNUTLS */