src/common/ssl.c

   1 /*
   2  * Sylpheed -- a GTK+ based, lightweight, and fast e-mail client
   3  * Copyright (C) 1999-2011 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 #endif
  23
  24 #ifdef USE_GNUTLS
  25 #include "defs.h"
  26
  27 #include <stdlib.h>
  28 #include <glib.h>
  29 #include <glib/gi18n.h>
  30 #include <errno.h>
  31 #include <pthread.h>
  32
  33 #if GNUTLS_VERSION_NUMBER <= 0x020b00
  34 #include <gcrypt.h>
  35 GCRY_THREAD_OPTION_PTHREAD_IMPL;
  36 #endif
  37
  38 #include "claws.h"
  39 #include "utils.h"
  40 #include "ssl.h"
  41 #include "ssl_certificate.h"
  42 #include "hooks.h"
  43
  44 #ifdef HAVE_LIBETPAN
  45 #include <libetpan/mailstream_ssl.h>
  46 #endif
  47
  48 #ifdef USE_PTHREAD
  49 #include <pthread.h>
  50 #endif
  51
  52 #ifdef USE_PTHREAD
  53 typedef struct _thread_data {
  54         gnutls_session ssl;
  55         gboolean done;
  56 } thread_data;
  57 #endif
  58
  59 static int gnutls_client_cert_cb(gnutls_session session,
  60                                const gnutls_datum *req_ca_rdn, int nreqs,
  61                                const gnutls_pk_algorithm *sign_algos,
  62                                int sign_algos_length, gnutls_retr_st *st)
  63 {
  64         SSLClientCertHookData hookdata;
  65         SockInfo *sockinfo = (SockInfo *)gnutls_session_get_ptr(session);
  66         gnutls_certificate_type type = gnutls_certificate_type_get(session);
  67         gnutls_x509_crt crt;
  68         gnutls_x509_privkey key;
  69
  70         st->ncerts = 0;
  71
  72         hookdata.account = sockinfo->account;
  73         hookdata.cert_path = NULL;
  74         hookdata.password = NULL;
  75         hookdata.is_smtp = sockinfo->is_smtp;
  76         hooks_invoke(SSLCERT_GET_CLIENT_CERT_HOOKLIST, &hookdata);
  77
  78         if (hookdata.cert_path == NULL)
  79                 return 0;
  80
  81         sockinfo->client_crt = ssl_certificate_get_x509_from_pem_file(hookdata.cert_path);
  82         sockinfo->client_key = ssl_certificate_get_pkey_from_pem_file(hookdata.cert_path);
  83         if (!(sockinfo->client_crt && sockinfo->client_key)) {
  84                 /* try pkcs12 format */
  85                 ssl_certificate_get_x509_and_pkey_from_p12_file(hookdata.cert_path, hookdata.password,
  86                         &crt, &key);
  87                 sockinfo->client_crt = crt;
  88                 sockinfo->client_key = key;
  89         }
  90
  91         if (type == GNUTLS_CRT_X509 && sockinfo->client_crt && sockinfo->client_key) {
  92                 st->ncerts = 1;
  93                 st->type = type;
  94                 st->cert.x509 = &(sockinfo->client_crt);
  95                 st->key.x509 = sockinfo->client_key;
  96                 st->deinit_all = 0;
  97                 return 0;
  98         }
  99         return 0;
 100 }
 101
 102 const gchar *claws_ssl_get_cert_file(void)
 103 {
 104         const char *cert_files[]={
 105                 "/etc/pki/tls/certs/ca-bundle.crt",
 106                 "/etc/certs/ca-bundle.crt",
 107                 "/usr/share/ssl/certs/ca-bundle.crt",
 108                 "/etc/ssl/certs/ca-certificates.crt",
 109                 "/usr/local/ssl/certs/ca-bundle.crt",
 110                 "/etc/apache/ssl.crt/ca-bundle.crt",
 111                 "/usr/share/curl/curl-ca-bundle.crt",
 112                 "/usr/share/curl/curl-ca-bundle.crt",
 113                 "/usr/lib/ssl/cert.pem",
 114                 NULL};
 115         int i;
 116
 117         if (g_getenv("SSL_CERT_FILE"))
 118                 return g_getenv("SSL_CERT_FILE");
 119 #ifndef G_OS_WIN32
 120         for (i = 0; cert_files[i]; i++) {
 121                 if (is_file_exist(cert_files[i]))
 122                         return cert_files[i];
 123         }
 124         return NULL;
 125 #else
 126         return get_cert_file();
 127 #endif
 128 }
 129
 130 const gchar *claws_ssl_get_cert_dir(void)
 131 {
 132         const char *cert_dirs[]={
 133                 "/etc/pki/tls/certs",
 134                 "/etc/certs",
 135                 "/usr/share/ssl/certs",
 136                 "/etc/ssl/certs",
 137                 "/usr/local/ssl/certs",
 138                 "/etc/apache/ssl.crt",
 139                 "/usr/share/curl",
 140                 "/usr/lib/ssl/certs",
 141                 NULL};
 142         int i;
 143
 144         if (g_getenv("SSL_CERT_DIR"))
 145                 return g_getenv("SSL_CERT_DIR");
 146 #ifndef G_OS_WIN32
 147         for (i = 0; cert_dirs[i]; i++) {
 148                 if (is_dir_exist(cert_dirs[i]))
 149                         return cert_dirs[i];
 150         }
 151         return NULL;
 152 #else
 153         return "put_what_s_needed_here";
 154 #endif
 155 }
 156
 157 void ssl_init(void)
 158 {
 159 #if GNUTLS_VERSION_NUMBER <= 0x020b00
 160         gcry_control (GCRYCTL_SET_THREAD_CBS, &gcry_threads_pthread);
 161 #endif
 162 #ifdef HAVE_LIBETPAN
 163         mailstream_gnutls_init_not_required();
 164 #endif
 165         gnutls_global_init();
 166 }
 167
 168 void ssl_done(void)
 169 {
 170         gnutls_global_deinit();
 171 }
 172
 173 #ifdef USE_PTHREAD
 174 static void *SSL_connect_thread(void *data)
 175 {
 176         thread_data *td = (thread_data *)data;
 177         int result = -1;
 178
 179         pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, NULL);
 180         pthread_setcanceltype(PTHREAD_CANCEL_ASYNCHRONOUS, NULL);
 181
 182         do {
 183                 result = gnutls_handshake(td->ssl);
 184         } while (result == GNUTLS_E_AGAIN || result == GNUTLS_E_INTERRUPTED);
 185
 186         td->done = TRUE; /* let the caller thread join() */
 187         return GINT_TO_POINTER(result);
 188 }
 189 #endif
 190
 191 static gint SSL_connect_nb(gnutls_session ssl)
 192 {
 193         int result;
 194 #ifdef USE_PTHREAD
 195         thread_data *td = g_new0(thread_data, 1);
 196         pthread_t pt;
 197         pthread_attr_t pta;
 198         void *res = NULL;
 199         time_t start_time = time(NULL);
 200         gboolean killed = FALSE;
 201
 202         td->ssl  = ssl;
 203         td->done = FALSE;
 204
 205         /* try to create a thread to initialize the SSL connection,
 206          * fallback to blocking method in case of problem
 207          */
 208         if (pthread_attr_init(&pta) != 0 ||
 209             pthread_attr_setdetachstate(&pta, PTHREAD_CREATE_JOINABLE) != 0 ||
 210             pthread_create(&pt, &pta, SSL_connect_thread, td) != 0) {
 211                 do {
 212                         result = gnutls_handshake(td->ssl);
 213                 } while (result == GNUTLS_E_AGAIN || result == GNUTLS_E_INTERRUPTED);
 214                 return result;
 215         }
 216         debug_print("waiting for SSL_connect thread...\n");
 217         while(!td->done) {
 218                 /* don't let the interface freeze while waiting */
 219                 claws_do_idle();
 220                 if (time(NULL) - start_time > 30) {
 221                         pthread_cancel(pt);
 222                         td->done = TRUE;
 223                         killed = TRUE;
 224                 }
 225         }
 226
 227         /* get the thread's return value and clean its resources */
 228         pthread_join(pt, &res);
 229         g_free(td);
 230
 231         if (killed) {
 232                 res = GINT_TO_POINTER(-1);
 233         }
 234         debug_print("SSL_connect thread returned %d\n",
 235                         GPOINTER_TO_INT(res));
 236
 237         return GPOINTER_TO_INT(res);
 238 #else /* USE_PTHREAD */
 239         do {
 240                 result = gnutls_handshake(ssl);
 241         } while (result == GNUTLS_E_AGAIN || result == GNUTLS_E_INTERRUPTED);
 242 #endif
 243 }
 244
 245 gboolean ssl_init_socket(SockInfo *sockinfo)
 246 {
 247         return ssl_init_socket_with_method(sockinfo, SSL_METHOD_SSLv23);
 248 }
 249
 250 gboolean ssl_init_socket_with_method(SockInfo *sockinfo, SSLMethod method)
 251 {
 252         gnutls_session session;
 253         int r;
 254         const gnutls_datum *raw_cert_list;
 255         unsigned int raw_cert_list_length;
 256         gnutls_x509_crt cert = NULL;
 257         guint status;
 258         gnutls_certificate_credentials_t xcred;
 259
 260         if (gnutls_certificate_allocate_credentials (&xcred) != 0)
 261                 return FALSE;
 262
 263         r = gnutls_init(&session, GNUTLS_CLIENT);
 264         if (session == NULL || r != 0)
 265                 return FALSE;
 266
 267         gnutls_transport_set_lowat (session, 0);
 268
 269         gnutls_priority_set_direct(session, "NORMAL", NULL);
 270         gnutls_record_disable_padding(session);
 271
 272         gnutls_credentials_set(session, GNUTLS_CRD_CERTIFICATE, xcred);
 273
 274         if (claws_ssl_get_cert_file()) {
 275                 r = gnutls_certificate_set_x509_trust_file(xcred, claws_ssl_get_cert_file(),  GNUTLS_X509_FMT_PEM);
 276                 if (r < 0)
 277                         g_warning("Can't read SSL_CERT_FILE %s: %s\n",
 278                                 claws_ssl_get_cert_file(),
 279                                 gnutls_strerror(r));
 280         } else {
 281                 debug_print("Can't find SSL ca-certificates file\n");
 282         }
 283         gnutls_certificate_set_verify_flags (xcred, GNUTLS_VERIFY_ALLOW_X509_V1_CA_CRT);
 284
 285         gnutls_transport_set_ptr(session, (gnutls_transport_ptr) sockinfo->sock);
 286         gnutls_session_set_ptr(session, sockinfo);
 287         gnutls_certificate_client_set_retrieve_function(xcred, gnutls_client_cert_cb);
 288
 289         gnutls_dh_set_prime_bits(session, 512);
 290
 291         if ((r = SSL_connect_nb(session)) < 0) {
 292                 g_warning("SSL connection failed (%s)", gnutls_strerror(r));
 293                 gnutls_certificate_free_credentials(xcred);
 294                 gnutls_deinit(session);
 295                 return FALSE;
 296         }
 297
 298         /* Get server's certificate (note: beware of dynamic allocation) */
 299         raw_cert_list = gnutls_certificate_get_peers(session, &raw_cert_list_length);
 300
 301         if (!raw_cert_list
 302         ||  gnutls_certificate_type_get(session) != GNUTLS_CRT_X509
 303         ||  (r = gnutls_x509_crt_init(&cert)) < 0
 304         ||  (r = gnutls_x509_crt_import(cert, &raw_cert_list[0], GNUTLS_X509_FMT_DER)) < 0) {
 305                 g_warning("cert get failure: %d %s\n", r, gnutls_strerror(r));
 306                 gnutls_certificate_free_credentials(xcred);
 307                 gnutls_deinit(session);
 308                 return FALSE;
 309         }
 310
 311         r = gnutls_certificate_verify_peers2(session, &status);
 312
 313         if (!ssl_certificate_check(cert, status, sockinfo->hostname, sockinfo->port)) {
 314                 gnutls_x509_crt_deinit(cert);
 315                 gnutls_certificate_free_credentials(xcred);
 316                 gnutls_deinit(session);
 317                 return FALSE;
 318         }
 319
 320         gnutls_x509_crt_deinit(cert);
 321
 322         sockinfo->ssl = session;
 323         sockinfo->xcred = xcred;
 324         return TRUE;
 325 }
 326
 327 void ssl_done_socket(SockInfo *sockinfo)
 328 {
 329         if (sockinfo && sockinfo->ssl) {
 330                 gnutls_certificate_free_credentials(sockinfo->xcred);
 331                 gnutls_deinit(sockinfo->ssl);
 332                 if (sockinfo->client_crt)
 333                         gnutls_x509_crt_deinit(sockinfo->client_crt);
 334                 if (sockinfo->client_key)
 335                         gnutls_x509_privkey_deinit(sockinfo->client_key);
 336                 sockinfo->client_key = NULL;
 337                 sockinfo->client_crt = NULL;
 338                 sockinfo->ssl = NULL;
 339         }
 340 }
 341
 342 #endif /* USE_GNUTLS */