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 < 0x030400
  61 #define DEFAULT_GNUTLS_PRIORITY "NORMAL:-VERS-SSL3.0"
  62 #else
  63 #define DEFAULT_GNUTLS_PRIORITY "NORMAL"
  64 #endif
  65
  66 #if GNUTLS_VERSION_NUMBER <= 0x020c00
  67 static int gnutls_client_cert_cb(gnutls_session_t session,
  68                                const gnutls_datum_t *req_ca_rdn, int nreqs,
  69                                const gnutls_pk_algorithm_t *sign_algos,
  70                                int sign_algos_length, gnutls_retr_st *st)
  71 #else
  72 static int gnutls_cert_cb(gnutls_session_t session,
  73                                const gnutls_datum_t *req_ca_rdn, int nreqs,
  74                                const gnutls_pk_algorithm_t *sign_algos,
  75                                int sign_algos_length, gnutls_retr2_st *st)
  76 #endif
  77 {
  78         SSLClientCertHookData hookdata;
  79         SockInfo *sockinfo = (SockInfo *)gnutls_session_get_ptr(session);
  80         gnutls_certificate_type_t type = gnutls_certificate_type_get(session);
  81         gnutls_x509_crt_t crt;
  82         gnutls_x509_privkey_t key;
  83
  84         st->ncerts = 0;
  85
  86         hookdata.account = sockinfo->account;
  87         hookdata.cert_path = NULL;
  88         hookdata.password = NULL;
  89         hookdata.is_smtp = sockinfo->is_smtp;
  90         hooks_invoke(SSLCERT_GET_CLIENT_CERT_HOOKLIST, &hookdata);
  91
  92         if (hookdata.cert_path == NULL) {
  93                 g_free(hookdata.password);
  94                 return 0;
  95         }
  96
  97         sockinfo->client_crt = ssl_certificate_get_x509_from_pem_file(hookdata.cert_path);
  98         sockinfo->client_key = ssl_certificate_get_pkey_from_pem_file(hookdata.cert_path);
  99         if (!(sockinfo->client_crt && sockinfo->client_key)) {
 100                 /* try pkcs12 format */
 101                 ssl_certificate_get_x509_and_pkey_from_p12_file(hookdata.cert_path, hookdata.password,
 102                         &crt, &key);
 103                 sockinfo->client_crt = crt;
 104                 sockinfo->client_key = key;
 105         }
 106
 107         if (type == GNUTLS_CRT_X509 && sockinfo->client_crt && sockinfo->client_key) {
 108                 st->ncerts = 1;
 109 #if GNUTLS_VERSION_NUMBER <= 0x020c00
 110                 st->type = type;
 111 #else
 112                 st->key_type = type;
 113 #endif
 114                 st->cert.x509 = &(sockinfo->client_crt);
 115                 st->key.x509 = sockinfo->client_key;
 116                 st->deinit_all = 0;
 117                 g_free(hookdata.password);
 118                 return 0;
 119         }
 120         g_free(hookdata.password);
 121         return 0;
 122 }
 123
 124 const gchar *claws_ssl_get_cert_file(void)
 125 {
 126 #ifndef G_OS_WIN32
 127         const char *cert_files[]={
 128                 "/etc/pki/tls/certs/ca-bundle.crt",
 129                 "/etc/certs/ca-bundle.crt",
 130                 "/etc/ssl/ca-bundle.pem",
 131                 "/usr/share/ssl/certs/ca-bundle.crt",
 132                 "/etc/ssl/certs/ca-certificates.crt",
 133                 "/usr/local/ssl/certs/ca-bundle.crt",
 134                 "/etc/apache/ssl.crt/ca-bundle.crt",
 135                 "/usr/share/curl/curl-ca-bundle.crt",
 136                 "/usr/share/curl/curl-ca-bundle.crt",
 137                 "/usr/lib/ssl/cert.pem",
 138                 NULL};
 139         int i;
 140 #endif
 141
 142         /* We honor this environment variable on all platforms. */
 143         if (g_getenv("SSL_CERT_FILE"))
 144                 return g_getenv("SSL_CERT_FILE");
 145
 146 #ifndef G_OS_WIN32
 147         for (i = 0; cert_files[i]; i++) {
 148                 if (is_file_exist(cert_files[i]))
 149                         return cert_files[i];
 150         }
 151         return NULL;
 152 #else
 153         return w32_get_cert_file();
 154 #endif
 155 }
 156
 157 const gchar *claws_ssl_get_cert_dir(void)
 158 {
 159         const char *cert_dirs[]={
 160                 "/etc/pki/tls/certs",
 161                 "/etc/certs",
 162                 "/usr/share/ssl/certs",
 163                 "/etc/ssl/certs",
 164                 "/usr/local/ssl/certs",
 165                 "/etc/apache/ssl.crt",
 166                 "/usr/share/curl",
 167                 "/usr/lib/ssl/certs",
 168                 NULL};
 169         int i;
 170
 171         if (g_getenv("SSL_CERT_DIR"))
 172                 return g_getenv("SSL_CERT_DIR");
 173 #ifndef G_OS_WIN32
 174         for (i = 0; cert_dirs[i]; i++) {
 175                 if (is_dir_exist(cert_dirs[i]))
 176                         return cert_dirs[i];
 177         }
 178         return NULL;
 179 #else
 180         return NULL;
 181 #endif
 182 }
 183
 184 void ssl_init(void)
 185 {
 186 #if GNUTLS_VERSION_NUMBER <= 0x020b00
 187         gcry_control (GCRYCTL_SET_THREAD_CBS, &gcry_threads_pthread);
 188 #endif
 189 #ifdef HAVE_LIBETPAN
 190         mailstream_gnutls_init_not_required();
 191 #endif
 192         gnutls_global_init();
 193 }
 194
 195 void ssl_done(void)
 196 {
 197         gnutls_global_deinit();
 198 }
 199
 200 #ifdef USE_PTHREAD
 201 static void *SSL_connect_thread(void *data)
 202 {
 203         thread_data *td = (thread_data *)data;
 204         int result = -1;
 205
 206         pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, NULL);
 207         pthread_setcanceltype(PTHREAD_CANCEL_ASYNCHRONOUS, NULL);
 208
 209         do {
 210                 result = gnutls_handshake(td->ssl);
 211         } while (result == GNUTLS_E_AGAIN || result == GNUTLS_E_INTERRUPTED);
 212
 213         td->done = TRUE; /* let the caller thread join() */
 214         return GINT_TO_POINTER(result);
 215 }
 216 #endif
 217
 218 static gint SSL_connect_nb(gnutls_session_t ssl)
 219 {
 220         int result;
 221 #ifdef USE_PTHREAD
 222         thread_data *td = g_new0(thread_data, 1);
 223         pthread_t pt;
 224         pthread_attr_t pta;
 225         void *res = NULL;
 226         time_t start_time = time(NULL);
 227         gboolean killed = FALSE;
 228
 229         td->ssl  = ssl;
 230         td->done = FALSE;
 231
 232         /* try to create a thread to initialize the SSL connection,
 233          * fallback to blocking method in case of problem
 234          */
 235         if (pthread_attr_init(&pta) != 0 ||
 236             pthread_attr_setdetachstate(&pta, PTHREAD_CREATE_JOINABLE) != 0 ||
 237             pthread_create(&pt, &pta, SSL_connect_thread, td) != 0) {
 238                 do {
 239                         result = gnutls_handshake(td->ssl);
 240                 } while (result == GNUTLS_E_AGAIN || result == GNUTLS_E_INTERRUPTED);
 241                 return result;
 242         }
 243         debug_print("waiting for SSL_connect thread...\n");
 244         while(!td->done) {
 245                 /* don't let the interface freeze while waiting */
 246                 claws_do_idle();
 247                 if (time(NULL) - start_time > 30) {
 248                         pthread_cancel(pt);
 249                         td->done = TRUE;
 250                         killed = TRUE;
 251                 }
 252         }
 253
 254         /* get the thread's return value and clean its resources */
 255         pthread_join(pt, &res);
 256         g_free(td);
 257
 258         if (killed) {
 259                 res = GINT_TO_POINTER(-1);
 260         }
 261         debug_print("SSL_connect thread returned %d\n",
 262                         GPOINTER_TO_INT(res));
 263
 264         return GPOINTER_TO_INT(res);
 265 #else /* USE_PTHREAD */
 266         do {
 267                 result = gnutls_handshake(ssl);
 268         } while (result == GNUTLS_E_AGAIN || result == GNUTLS_E_INTERRUPTED);
 269 #endif
 270 }
 271
 272 gnutls_x509_crt_t *ssl_get_certificate_chain(gnutls_session_t session, gint *list_len)
 273 {
 274         const gnutls_datum_t *raw_cert_list;
 275         gnutls_x509_crt_t *certs = NULL;
 276         gboolean result = TRUE;
 277
 278         *list_len = -1;
 279         if (!session)
 280                 return NULL;
 281
 282         raw_cert_list = gnutls_certificate_get_peers(session, list_len);
 283
 284         if (raw_cert_list && gnutls_certificate_type_get(session) == GNUTLS_CRT_X509) {
 285                 int i = 0;
 286
 287                 if (*list_len > 128)
 288                         *list_len = 128;
 289
 290                 certs = g_malloc(sizeof(gnutls_x509_crt_t) * (*list_len));
 291
 292                 for(i = 0 ; i < (*list_len) ; i++) {
 293                         int r;
 294
 295                         gnutls_x509_crt_init(&certs[i]);
 296                         r = gnutls_x509_crt_import(certs[i], &raw_cert_list[i], GNUTLS_X509_FMT_DER);
 297                         if (r < 0) {
 298                                 g_warning("cert get failure: %d %s", r, gnutls_strerror(r));
 299
 300                                 result = FALSE;
 301                                 i--;
 302                                 break;
 303                         }
 304                 }
 305                 if (!result) {
 306                         for (; i >= 0; i--)
 307                                 gnutls_x509_crt_deinit(certs[i]);
 308
 309                         g_free(certs);
 310                         *list_len = -1;
 311
 312                         return NULL;
 313                 }
 314         }
 315
 316         return certs;
 317 }
 318
 319 gboolean ssl_init_socket(SockInfo *sockinfo)
 320 {
 321         gnutls_session_t session;
 322         int r, i;
 323         unsigned int cert_list_length;
 324         gnutls_x509_crt_t *certs = NULL;
 325         gnutls_certificate_credentials_t xcred;
 326
 327         if (gnutls_certificate_allocate_credentials (&xcred) != 0)
 328                 return FALSE;
 329
 330         r = gnutls_init(&session, GNUTLS_CLIENT);
 331         if (session == NULL || r != 0)
 332                 return FALSE;
 333
 334         if (sockinfo->gnutls_priority && strlen(sockinfo->gnutls_priority)) {
 335                 r = gnutls_priority_set_direct(session, sockinfo->gnutls_priority, NULL);
 336                 debug_print("Setting GnuTLS priority to %s, status = %d\n",
 337                             sockinfo->gnutls_priority, r);
 338         }
 339         else {
 340                 gnutls_priority_set_direct(session, DEFAULT_GNUTLS_PRIORITY, NULL);
 341         }
 342
 343         gnutls_record_disable_padding(session);
 344
 345         gnutls_credentials_set(session, GNUTLS_CRD_CERTIFICATE, xcred);
 346
 347         if (claws_ssl_get_cert_file()) {
 348                 r = gnutls_certificate_set_x509_trust_file(xcred, claws_ssl_get_cert_file(),  GNUTLS_X509_FMT_PEM);
 349                 if (r < 0)
 350                         g_warning("Can't read SSL_CERT_FILE '%s': %s",
 351                                 claws_ssl_get_cert_file(),
 352                                 gnutls_strerror(r));
 353         } else {
 354                 debug_print("Can't find SSL ca-certificates file\n");
 355         }
 356         gnutls_certificate_set_verify_flags (xcred, GNUTLS_VERIFY_ALLOW_X509_V1_CA_CRT);
 357
 358         gnutls_transport_set_ptr(session, (gnutls_transport_ptr_t) GINT_TO_POINTER(sockinfo->sock));
 359         gnutls_session_set_ptr(session, sockinfo);
 360 #if GNUTLS_VERSION_NUMBER <= 0x020c00
 361         gnutls_certificate_client_set_retrieve_function(xcred, gnutls_client_cert_cb);
 362 #else
 363         gnutls_certificate_set_retrieve_function(xcred, gnutls_cert_cb);
 364 #endif
 365
 366         gnutls_dh_set_prime_bits(session, 512);
 367
 368         if ((r = SSL_connect_nb(session)) < 0) {
 369                 g_warning("SSL connection failed (%s)", gnutls_strerror(r));
 370                 gnutls_certificate_free_credentials(xcred);
 371                 gnutls_deinit(session);
 372                 return FALSE;
 373         }
 374
 375         /* Get server's certificate (note: beware of dynamic allocation) */
 376         certs = ssl_get_certificate_chain(session, &cert_list_length);
 377
 378         if (!certs) {
 379                 gnutls_certificate_free_credentials(xcred);
 380                 gnutls_deinit(session);
 381                 return FALSE;
 382         }
 383
 384         if (!ssl_certificate_check_chain(certs, cert_list_length, sockinfo->hostname, sockinfo->port,
 385                                          sockinfo->ssl_cert_auto_accept)) {
 386                 for (i = 0; i < cert_list_length; i++)
 387                         gnutls_x509_crt_deinit(certs[i]);
 388                 g_free(certs);
 389                 gnutls_certificate_free_credentials(xcred);
 390                 gnutls_deinit(session);
 391                 return FALSE;
 392         }
 393
 394         for (i = 0; i < cert_list_length; i++)
 395                 gnutls_x509_crt_deinit(certs[i]);
 396         g_free(certs);
 397
 398         sockinfo->ssl = session;
 399         sockinfo->xcred = xcred;
 400         return TRUE;
 401 }
 402
 403 void ssl_done_socket(SockInfo *sockinfo)
 404 {
 405         if (sockinfo && sockinfo->ssl) {
 406                 if (sockinfo->xcred)
 407                         gnutls_certificate_free_credentials(sockinfo->xcred);
 408                 gnutls_deinit(sockinfo->ssl);
 409                 if (sockinfo->client_crt)
 410                         gnutls_x509_crt_deinit(sockinfo->client_crt);
 411                 if (sockinfo->client_key)
 412                         gnutls_x509_privkey_deinit(sockinfo->client_key);
 413                 sockinfo->client_key = NULL;
 414                 sockinfo->client_crt = NULL;
 415                 sockinfo->xcred = NULL;
 416                 sockinfo->ssl = NULL;
 417         }
 418 }
 419
 420 #endif /* USE_GNUTLS */