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                 return 0;
  88
  89         sockinfo->client_crt = ssl_certificate_get_x509_from_pem_file(hookdata.cert_path);
  90         sockinfo->client_key = ssl_certificate_get_pkey_from_pem_file(hookdata.cert_path);
  91         if (!(sockinfo->client_crt && sockinfo->client_key)) {
  92                 /* try pkcs12 format */
  93                 ssl_certificate_get_x509_and_pkey_from_p12_file(hookdata.cert_path, hookdata.password,
  94                         &crt, &key);
  95                 sockinfo->client_crt = crt;
  96                 sockinfo->client_key = key;
  97         }
  98
  99         if (type == GNUTLS_CRT_X509 && sockinfo->client_crt && sockinfo->client_key) {
 100                 st->ncerts = 1;
 101 #if GNUTLS_VERSION_NUMBER <= 0x020c00
 102                 st->type = type;
 103 #else
 104                 st->key_type = type;
 105 #endif
 106                 st->cert.x509 = &(sockinfo->client_crt);
 107                 st->key.x509 = sockinfo->client_key;
 108                 st->deinit_all = 0;
 109                 return 0;
 110         }
 111         return 0;
 112 }
 113
 114 const gchar *claws_ssl_get_cert_file(void)
 115 {
 116         const char *cert_files[]={
 117                 "/etc/pki/tls/certs/ca-bundle.crt",
 118                 "/etc/certs/ca-bundle.crt",
 119                 "/etc/ssl/ca-bundle.pem",
 120                 "/usr/share/ssl/certs/ca-bundle.crt",
 121                 "/etc/ssl/certs/ca-certificates.crt",
 122                 "/usr/local/ssl/certs/ca-bundle.crt",
 123                 "/etc/apache/ssl.crt/ca-bundle.crt",
 124                 "/usr/share/curl/curl-ca-bundle.crt",
 125                 "/usr/share/curl/curl-ca-bundle.crt",
 126                 "/usr/lib/ssl/cert.pem",
 127                 NULL};
 128         int i;
 129
 130         if (g_getenv("SSL_CERT_FILE"))
 131                 return g_getenv("SSL_CERT_FILE");
 132 #ifndef G_OS_WIN32
 133         for (i = 0; cert_files[i]; i++) {
 134                 if (is_file_exist(cert_files[i]))
 135                         return cert_files[i];
 136         }
 137         return NULL;
 138 #else
 139         return get_cert_file();
 140 #endif
 141 }
 142
 143 const gchar *claws_ssl_get_cert_dir(void)
 144 {
 145         const char *cert_dirs[]={
 146                 "/etc/pki/tls/certs",
 147                 "/etc/certs",
 148                 "/usr/share/ssl/certs",
 149                 "/etc/ssl/certs",
 150                 "/usr/local/ssl/certs",
 151                 "/etc/apache/ssl.crt",
 152                 "/usr/share/curl",
 153                 "/usr/lib/ssl/certs",
 154                 NULL};
 155         int i;
 156
 157         if (g_getenv("SSL_CERT_DIR"))
 158                 return g_getenv("SSL_CERT_DIR");
 159 #ifndef G_OS_WIN32
 160         for (i = 0; cert_dirs[i]; i++) {
 161                 if (is_dir_exist(cert_dirs[i]))
 162                         return cert_dirs[i];
 163         }
 164         return NULL;
 165 #else
 166         return NULL;
 167 #endif
 168 }
 169
 170 void ssl_init(void)
 171 {
 172 #if GNUTLS_VERSION_NUMBER <= 0x020b00
 173         gcry_control (GCRYCTL_SET_THREAD_CBS, &gcry_threads_pthread);
 174 #endif
 175 #ifdef HAVE_LIBETPAN
 176         mailstream_gnutls_init_not_required();
 177 #endif
 178         gnutls_global_init();
 179 }
 180
 181 void ssl_done(void)
 182 {
 183         gnutls_global_deinit();
 184 }
 185
 186 #ifdef USE_PTHREAD
 187 static void *SSL_connect_thread(void *data)
 188 {
 189         thread_data *td = (thread_data *)data;
 190         int result = -1;
 191
 192         pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, NULL);
 193         pthread_setcanceltype(PTHREAD_CANCEL_ASYNCHRONOUS, NULL);
 194
 195         do {
 196                 result = gnutls_handshake(td->ssl);
 197         } while (result == GNUTLS_E_AGAIN || result == GNUTLS_E_INTERRUPTED);
 198
 199         td->done = TRUE; /* let the caller thread join() */
 200         return GINT_TO_POINTER(result);
 201 }
 202 #endif
 203
 204 static gint SSL_connect_nb(gnutls_session_t ssl)
 205 {
 206         int result;
 207 #ifdef USE_PTHREAD
 208         thread_data *td = g_new0(thread_data, 1);
 209         pthread_t pt;
 210         pthread_attr_t pta;
 211         void *res = NULL;
 212         time_t start_time = time(NULL);
 213         gboolean killed = FALSE;
 214
 215         td->ssl  = ssl;
 216         td->done = FALSE;
 217
 218         /* try to create a thread to initialize the SSL connection,
 219          * fallback to blocking method in case of problem
 220          */
 221         if (pthread_attr_init(&pta) != 0 ||
 222             pthread_attr_setdetachstate(&pta, PTHREAD_CREATE_JOINABLE) != 0 ||
 223             pthread_create(&pt, &pta, SSL_connect_thread, td) != 0) {
 224                 do {
 225                         result = gnutls_handshake(td->ssl);
 226                 } while (result == GNUTLS_E_AGAIN || result == GNUTLS_E_INTERRUPTED);
 227                 return result;
 228         }
 229         debug_print("waiting for SSL_connect thread...\n");
 230         while(!td->done) {
 231                 /* don't let the interface freeze while waiting */
 232                 claws_do_idle();
 233                 if (time(NULL) - start_time > 30) {
 234                         pthread_cancel(pt);
 235                         td->done = TRUE;
 236                         killed = TRUE;
 237                 }
 238         }
 239
 240         /* get the thread's return value and clean its resources */
 241         pthread_join(pt, &res);
 242         g_free(td);
 243
 244         if (killed) {
 245                 res = GINT_TO_POINTER(-1);
 246         }
 247         debug_print("SSL_connect thread returned %d\n",
 248                         GPOINTER_TO_INT(res));
 249
 250         return GPOINTER_TO_INT(res);
 251 #else /* USE_PTHREAD */
 252         do {
 253                 result = gnutls_handshake(ssl);
 254         } while (result == GNUTLS_E_AGAIN || result == GNUTLS_E_INTERRUPTED);
 255 #endif
 256 }
 257
 258 gboolean ssl_init_socket(SockInfo *sockinfo)
 259 {
 260         return ssl_init_socket_with_method(sockinfo, SSL_METHOD_SSLv23);
 261 }
 262
 263 gnutls_x509_crt_t *ssl_get_certificate_chain(gnutls_session_t session, gint *list_len)
 264 {
 265         const gnutls_datum_t *raw_cert_list;
 266         gnutls_x509_crt_t *certs = NULL;
 267         gboolean result = TRUE;
 268
 269         *list_len = -1;
 270         if (!session)
 271                 return NULL;
 272
 273         raw_cert_list = gnutls_certificate_get_peers(session, list_len);
 274
 275         if (raw_cert_list && gnutls_certificate_type_get(session) == GNUTLS_CRT_X509) {
 276                 int i = 0;
 277
 278                 certs = g_malloc(sizeof(gnutls_x509_crt_t) * (*list_len));
 279
 280                 for(i = 0 ; i < (*list_len) ; i++) {
 281                         int r;
 282
 283                         gnutls_x509_crt_init(&certs[i]);
 284                         r = gnutls_x509_crt_import(certs[i], &raw_cert_list[i], GNUTLS_X509_FMT_DER);
 285                         if (r < 0) {
 286                                 g_warning("cert get failure: %d %s\n", r, gnutls_strerror(r));
 287
 288                                 result = FALSE;
 289                                 i--;
 290                                 break;
 291                         }
 292                 }
 293                 if (!result) {
 294                         for (; i >= 0; i--)
 295                                 gnutls_x509_crt_deinit(certs[i]);
 296
 297                         g_free(certs);
 298                         *list_len = -1;
 299
 300                         return NULL;
 301                 }
 302         }
 303
 304         return certs;
 305 }
 306
 307 gboolean ssl_init_socket_with_method(SockInfo *sockinfo, SSLMethod method)
 308 {
 309         gnutls_session_t session;
 310         int r, i;
 311         unsigned int cert_list_length;
 312         gnutls_x509_crt_t *certs = NULL;
 313         gnutls_certificate_credentials_t xcred;
 314
 315         if (gnutls_certificate_allocate_credentials (&xcred) != 0)
 316                 return FALSE;
 317
 318         r = gnutls_init(&session, GNUTLS_CLIENT);
 319         if (session == NULL || r != 0)
 320                 return FALSE;
 321
 322         if (sockinfo->gnutls_priority && strlen(sockinfo->gnutls_priority)) {
 323                 r = gnutls_priority_set_direct(session, sockinfo->gnutls_priority, NULL);
 324                 debug_print("Setting GnuTLS priority to %s, status = %d\n",
 325                             sockinfo->gnutls_priority, r);
 326         }
 327         else {
 328                 if (method == 0)
 329                         gnutls_priority_set_direct(session, "NORMAL:-VERS-TLS1.0:-VERS-TLS1.1:-VERS-TLS1.2", NULL);
 330                 else
 331                         gnutls_priority_set_direct(session, "NORMAL", NULL);
 332         }
 333         gnutls_record_disable_padding(session);
 334
 335         gnutls_credentials_set(session, GNUTLS_CRD_CERTIFICATE, xcred);
 336
 337         if (claws_ssl_get_cert_file()) {
 338                 r = gnutls_certificate_set_x509_trust_file(xcred, claws_ssl_get_cert_file(),  GNUTLS_X509_FMT_PEM);
 339                 if (r < 0)
 340                         g_warning("Can't read SSL_CERT_FILE %s: %s\n",
 341                                 claws_ssl_get_cert_file(),
 342                                 gnutls_strerror(r));
 343         } else {
 344                 debug_print("Can't find SSL ca-certificates file\n");
 345         }
 346         gnutls_certificate_set_verify_flags (xcred, GNUTLS_VERIFY_ALLOW_X509_V1_CA_CRT);
 347
 348         gnutls_transport_set_ptr(session, (gnutls_transport_ptr_t) GINT_TO_POINTER(sockinfo->sock));
 349         gnutls_session_set_ptr(session, sockinfo);
 350 #if GNUTLS_VERSION_NUMBER <= 0x020c00
 351         gnutls_certificate_client_set_retrieve_function(xcred, gnutls_client_cert_cb);
 352 #else
 353         gnutls_certificate_set_retrieve_function(xcred, gnutls_cert_cb);
 354 #endif
 355
 356         gnutls_dh_set_prime_bits(session, 512);
 357
 358         if ((r = SSL_connect_nb(session)) < 0) {
 359                 g_warning("SSL connection failed (%s)", gnutls_strerror(r));
 360                 gnutls_certificate_free_credentials(xcred);
 361                 gnutls_deinit(session);
 362                 return FALSE;
 363         }
 364
 365         /* Get server's certificate (note: beware of dynamic allocation) */
 366         certs = ssl_get_certificate_chain(session, &cert_list_length);
 367
 368         if (!certs) {
 369                 gnutls_certificate_free_credentials(xcred);
 370                 gnutls_deinit(session);
 371                 return FALSE;
 372         }
 373
 374         if (!ssl_certificate_check_chain(certs, cert_list_length, sockinfo->hostname, sockinfo->port,
 375                                          sockinfo->ssl_cert_auto_accept)) {
 376                 for (i = 0; i < cert_list_length; i++)
 377                         gnutls_x509_crt_deinit(certs[i]);
 378                 g_free(certs);
 379                 gnutls_certificate_free_credentials(xcred);
 380                 gnutls_deinit(session);
 381                 return FALSE;
 382         }
 383
 384         for (i = 0; i < cert_list_length; i++)
 385                 gnutls_x509_crt_deinit(certs[i]);
 386         g_free(certs);
 387
 388         sockinfo->ssl = session;
 389         sockinfo->xcred = xcred;
 390         return TRUE;
 391 }
 392
 393 void ssl_done_socket(SockInfo *sockinfo)
 394 {
 395         if (sockinfo && sockinfo->ssl) {
 396                 if (sockinfo->xcred)
 397                         gnutls_certificate_free_credentials(sockinfo->xcred);
 398                 gnutls_deinit(sockinfo->ssl);
 399                 if (sockinfo->client_crt)
 400                         gnutls_x509_crt_deinit(sockinfo->client_crt);
 401                 if (sockinfo->client_key)
 402                         gnutls_x509_privkey_deinit(sockinfo->client_key);
 403                 sockinfo->client_key = NULL;
 404                 sockinfo->client_crt = NULL;
 405                 sockinfo->xcred = NULL;
 406                 sockinfo->ssl = NULL;
 407         }
 408 }
 409
 410 #endif /* USE_GNUTLS */