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 #if GNUTLS_VERSION_NUMBER <= 0x020b00
  35 #include <gcrypt.h>
  36 GCRY_THREAD_OPTION_PTHREAD_IMPL;
  37 #endif
  38
  39 #include "claws.h"
  40 #include "utils.h"
  41 #include "ssl.h"
  42 #include "ssl_certificate.h"
  43 #include "hooks.h"
  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 ssl;
  56         gboolean done;
  57 } thread_data;
  58 #endif
  59
  60 static int gnutls_client_cert_cb(gnutls_session session,
  61                                const gnutls_datum *req_ca_rdn, int nreqs,
  62                                const gnutls_pk_algorithm *sign_algos,
  63                                int sign_algos_length, gnutls_retr_st *st)
  64 {
  65         SSLClientCertHookData hookdata;
  66         SockInfo *sockinfo = (SockInfo *)gnutls_session_get_ptr(session);
  67         gnutls_certificate_type type = gnutls_certificate_type_get(session);
  68         gnutls_x509_crt crt;
  69         gnutls_x509_privkey key;
  70
  71         st->ncerts = 0;
  72
  73         hookdata.account = sockinfo->account;
  74         hookdata.cert_path = NULL;
  75         hookdata.password = NULL;
  76         hookdata.is_smtp = sockinfo->is_smtp;
  77         hooks_invoke(SSLCERT_GET_CLIENT_CERT_HOOKLIST, &hookdata);
  78
  79         if (hookdata.cert_path == NULL)
  80                 return 0;
  81
  82         sockinfo->client_crt = ssl_certificate_get_x509_from_pem_file(hookdata.cert_path);
  83         sockinfo->client_key = ssl_certificate_get_pkey_from_pem_file(hookdata.cert_path);
  84         if (!(sockinfo->client_crt && sockinfo->client_key)) {
  85                 /* try pkcs12 format */
  86                 ssl_certificate_get_x509_and_pkey_from_p12_file(hookdata.cert_path, hookdata.password,
  87                         &crt, &key);
  88                 sockinfo->client_crt = crt;
  89                 sockinfo->client_key = key;
  90         }
  91
  92         if (type == GNUTLS_CRT_X509 && sockinfo->client_crt && sockinfo->client_key) {
  93                 st->ncerts = 1;
  94                 st->type = type;
  95                 st->cert.x509 = &(sockinfo->client_crt);
  96                 st->key.x509 = sockinfo->client_key;
  97                 st->deinit_all = 0;
  98                 return 0;
  99         }
 100         return 0;
 101 }
 102
 103 const gchar *claws_ssl_get_cert_file(void)
 104 {
 105         const char *cert_files[]={
 106                 "/etc/pki/tls/certs/ca-bundle.crt",
 107                 "/etc/certs/ca-bundle.crt",
 108                 "/usr/share/ssl/certs/ca-bundle.crt",
 109                 "/etc/ssl/certs/ca-certificates.crt",
 110                 "/usr/local/ssl/certs/ca-bundle.crt",
 111                 "/etc/apache/ssl.crt/ca-bundle.crt",
 112                 "/usr/share/curl/curl-ca-bundle.crt",
 113                 "/usr/share/curl/curl-ca-bundle.crt",
 114                 "/usr/lib/ssl/cert.pem",
 115                 NULL};
 116         int i;
 117
 118         if (g_getenv("SSL_CERT_FILE"))
 119                 return g_getenv("SSL_CERT_FILE");
 120 #ifndef G_OS_WIN32
 121         for (i = 0; cert_files[i]; i++) {
 122                 if (is_file_exist(cert_files[i]))
 123                         return cert_files[i];
 124         }
 125         return NULL;
 126 #else
 127         return get_cert_file();
 128 #endif
 129 }
 130
 131 const gchar *claws_ssl_get_cert_dir(void)
 132 {
 133         const char *cert_dirs[]={
 134                 "/etc/pki/tls/certs",
 135                 "/etc/certs",
 136                 "/usr/share/ssl/certs",
 137                 "/etc/ssl/certs",
 138                 "/usr/local/ssl/certs",
 139                 "/etc/apache/ssl.crt",
 140                 "/usr/share/curl",
 141                 "/usr/lib/ssl/certs",
 142                 NULL};
 143         int i;
 144
 145         if (g_getenv("SSL_CERT_DIR"))
 146                 return g_getenv("SSL_CERT_DIR");
 147 #ifndef G_OS_WIN32
 148         for (i = 0; cert_dirs[i]; i++) {
 149                 if (is_dir_exist(cert_dirs[i]))
 150                         return cert_dirs[i];
 151         }
 152         return NULL;
 153 #else
 154         return "put_what_s_needed_here";
 155 #endif
 156 }
 157
 158 void ssl_init(void)
 159 {
 160 #if GNUTLS_VERSION_NUMBER <= 0x020b00
 161         gcry_control (GCRYCTL_SET_THREAD_CBS, &gcry_threads_pthread);
 162 #endif
 163 #ifdef HAVE_LIBETPAN
 164         mailstream_gnutls_init_not_required();
 165 #endif
 166         gnutls_global_init();
 167 }
 168
 169 void ssl_done(void)
 170 {
 171         gnutls_global_deinit();
 172 }
 173
 174 #ifdef USE_PTHREAD
 175 static void *SSL_connect_thread(void *data)
 176 {
 177         thread_data *td = (thread_data *)data;
 178         int result = -1;
 179
 180         pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, NULL);
 181         pthread_setcanceltype(PTHREAD_CANCEL_ASYNCHRONOUS, NULL);
 182
 183         do {
 184                 result = gnutls_handshake(td->ssl);
 185         } while (result == GNUTLS_E_AGAIN || result == GNUTLS_E_INTERRUPTED);
 186
 187         td->done = TRUE; /* let the caller thread join() */
 188         return GINT_TO_POINTER(result);
 189 }
 190 #endif
 191
 192 static gint SSL_connect_nb(gnutls_session ssl)
 193 {
 194         int result;
 195 #ifdef USE_PTHREAD
 196         thread_data *td = g_new0(thread_data, 1);
 197         pthread_t pt;
 198         pthread_attr_t pta;
 199         void *res = NULL;
 200         time_t start_time = time(NULL);
 201         gboolean killed = FALSE;
 202
 203         td->ssl  = ssl;
 204         td->done = FALSE;
 205
 206         /* try to create a thread to initialize the SSL connection,
 207          * fallback to blocking method in case of problem
 208          */
 209         if (pthread_attr_init(&pta) != 0 ||
 210             pthread_attr_setdetachstate(&pta, PTHREAD_CREATE_JOINABLE) != 0 ||
 211             pthread_create(&pt, &pta, SSL_connect_thread, td) != 0) {
 212                 do {
 213                         result = gnutls_handshake(td->ssl);
 214                 } while (result == GNUTLS_E_AGAIN || result == GNUTLS_E_INTERRUPTED);
 215                 return result;
 216         }
 217         debug_print("waiting for SSL_connect thread...\n");
 218         while(!td->done) {
 219                 /* don't let the interface freeze while waiting */
 220                 claws_do_idle();
 221                 if (time(NULL) - start_time > 30) {
 222                         pthread_cancel(pt);
 223                         td->done = TRUE;
 224                         killed = TRUE;
 225                 }
 226         }
 227
 228         /* get the thread's return value and clean its resources */
 229         pthread_join(pt, &res);
 230         g_free(td);
 231
 232         if (killed) {
 233                 res = GINT_TO_POINTER(-1);
 234         }
 235         debug_print("SSL_connect thread returned %d\n",
 236                         GPOINTER_TO_INT(res));
 237
 238         return GPOINTER_TO_INT(res);
 239 #else /* USE_PTHREAD */
 240         do {
 241                 result = gnutls_handshake(ssl);
 242         } while (result == GNUTLS_E_AGAIN || result == GNUTLS_E_INTERRUPTED);
 243 #endif
 244 }
 245
 246 gboolean ssl_init_socket(SockInfo *sockinfo)
 247 {
 248         return ssl_init_socket_with_method(sockinfo, SSL_METHOD_SSLv23);
 249 }
 250
 251 gboolean ssl_init_socket_with_method(SockInfo *sockinfo, SSLMethod method)
 252 {
 253         gnutls_session session;
 254         int r;
 255         const gnutls_datum *raw_cert_list;
 256         unsigned int raw_cert_list_length;
 257         gnutls_x509_crt cert = NULL;
 258         guint status;
 259         gnutls_certificate_credentials_t xcred;
 260
 261         if (gnutls_certificate_allocate_credentials (&xcred) != 0)
 262                 return FALSE;
 263
 264         r = gnutls_init(&session, GNUTLS_CLIENT);
 265         if (session == NULL || r != 0)
 266                 return FALSE;
 267
 268 #if GNUTLS_VERSION_NUMBER < 0x030003
 269         gnutls_transport_set_lowat (session, 0);
 270 #endif
 271         if (method == 0)
 272                 gnutls_priority_set_direct(session, "NORMAL:-VERS-TLS1.0:-VERS-TLS1.1:-VERS-TLS1.2", NULL);
 273         else
 274                 gnutls_priority_set_direct(session, "NORMAL", NULL);
 275         gnutls_record_disable_padding(session);
 276
 277         gnutls_credentials_set(session, GNUTLS_CRD_CERTIFICATE, xcred);
 278
 279         if (claws_ssl_get_cert_file()) {
 280                 r = gnutls_certificate_set_x509_trust_file(xcred, claws_ssl_get_cert_file(),  GNUTLS_X509_FMT_PEM);
 281                 if (r < 0)
 282                         g_warning("Can't read SSL_CERT_FILE %s: %s\n",
 283                                 claws_ssl_get_cert_file(),
 284                                 gnutls_strerror(r));
 285         } else {
 286                 debug_print("Can't find SSL ca-certificates file\n");
 287         }
 288         gnutls_certificate_set_verify_flags (xcred, GNUTLS_VERIFY_ALLOW_X509_V1_CA_CRT);
 289
 290         gnutls_transport_set_ptr(session, (gnutls_transport_ptr) sockinfo->sock);
 291         gnutls_session_set_ptr(session, sockinfo);
 292         gnutls_certificate_client_set_retrieve_function(xcred, gnutls_client_cert_cb);
 293
 294         gnutls_dh_set_prime_bits(session, 512);
 295
 296         if ((r = SSL_connect_nb(session)) < 0) {
 297                 g_warning("SSL connection failed (%s)", gnutls_strerror(r));
 298                 gnutls_certificate_free_credentials(xcred);
 299                 gnutls_deinit(session);
 300                 return FALSE;
 301         }
 302
 303         /* Get server's certificate (note: beware of dynamic allocation) */
 304         raw_cert_list = gnutls_certificate_get_peers(session, &raw_cert_list_length);
 305
 306         if (!raw_cert_list
 307         ||  gnutls_certificate_type_get(session) != GNUTLS_CRT_X509
 308         ||  (r = gnutls_x509_crt_init(&cert)) < 0
 309         ||  (r = gnutls_x509_crt_import(cert, &raw_cert_list[0], GNUTLS_X509_FMT_DER)) < 0) {
 310                 g_warning("cert get failure: %d %s\n", r, gnutls_strerror(r));
 311                 gnutls_certificate_free_credentials(xcred);
 312                 gnutls_deinit(session);
 313                 return FALSE;
 314         }
 315
 316         r = gnutls_certificate_verify_peers2(session, &status);
 317
 318         if (!ssl_certificate_check(cert, status, sockinfo->hostname, sockinfo->port)) {
 319                 gnutls_x509_crt_deinit(cert);
 320                 gnutls_certificate_free_credentials(xcred);
 321                 gnutls_deinit(session);
 322                 return FALSE;
 323         }
 324
 325         gnutls_x509_crt_deinit(cert);
 326
 327         sockinfo->ssl = session;
 328         sockinfo->xcred = xcred;
 329         return TRUE;
 330 }
 331
 332 void ssl_done_socket(SockInfo *sockinfo)
 333 {
 334         if (sockinfo && sockinfo->ssl) {
 335                 gnutls_certificate_free_credentials(sockinfo->xcred);
 336                 gnutls_deinit(sockinfo->ssl);
 337                 if (sockinfo->client_crt)
 338                         gnutls_x509_crt_deinit(sockinfo->client_crt);
 339                 if (sockinfo->client_key)
 340                         gnutls_x509_privkey_deinit(sockinfo->client_key);
 341                 sockinfo->client_key = NULL;
 342                 sockinfo->client_crt = NULL;
 343                 sockinfo->ssl = NULL;
 344         }
 345 }
 346
 347 #endif /* USE_GNUTLS */