src/common/ssl.c

   1 /*
   2  * Sylpheed -- a GTK+ based, lightweight, and fast e-mail client
   3  * Copyright (C) 1999-2007 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 #include <gcrypt.h>
  33 GCRY_THREAD_OPTION_PTHREAD_IMPL;
  34
  35 #include "claws.h"
  36 #include "utils.h"
  37 #include "ssl.h"
  38 #include "ssl_certificate.h"
  39 #include "hooks.h"
  40
  41 #ifdef HAVE_LIBETPAN
  42 #include <libetpan/mailstream_ssl.h>
  43 #endif
  44
  45 #ifdef USE_PTHREAD
  46 #include <pthread.h>
  47 #endif
  48
  49 #ifdef USE_PTHREAD
  50 typedef struct _thread_data {
  51         gnutls_session ssl;
  52         gboolean done;
  53 } thread_data;
  54 #endif
  55
  56 static int gnutls_client_cert_cb(gnutls_session session,
  57                                const gnutls_datum *req_ca_rdn, int nreqs,
  58                                const gnutls_pk_algorithm *sign_algos,
  59                                int sign_algos_length, gnutls_retr_st *st)
  60 {
  61         SSLClientCertHookData hookdata;
  62         SockInfo *sockinfo = (SockInfo *)gnutls_session_get_ptr(session);
  63         gnutls_certificate_type type = gnutls_certificate_type_get(session);
  64         gnutls_x509_crt crt;
  65         gnutls_x509_privkey key;
  66
  67         st->ncerts = 0;
  68
  69         hookdata.account = sockinfo->account;
  70         hookdata.cert_path = NULL;
  71         hookdata.password = NULL;
  72         hookdata.is_smtp = sockinfo->is_smtp;
  73         hooks_invoke(SSLCERT_GET_CLIENT_CERT_HOOKLIST, &hookdata);
  74
  75         if (hookdata.cert_path == NULL)
  76                 return 0;
  77
  78         sockinfo->client_crt = ssl_certificate_get_x509_from_pem_file(hookdata.cert_path);
  79         sockinfo->client_key = ssl_certificate_get_pkey_from_pem_file(hookdata.cert_path);
  80         if (!(sockinfo->client_crt && sockinfo->client_key)) {
  81                 /* try pkcs12 format */
  82                 ssl_certificate_get_x509_and_pkey_from_p12_file(hookdata.cert_path, hookdata.password,
  83                         &crt, &key);
  84                 sockinfo->client_crt = crt;
  85                 sockinfo->client_key = key;
  86         }
  87
  88         if (type == GNUTLS_CRT_X509 && sockinfo->client_crt && sockinfo->client_key) {
  89                 st->ncerts = 1;
  90                 st->type = type;
  91                 st->cert.x509 = &(sockinfo->client_crt);
  92                 st->key.x509 = sockinfo->client_key;
  93                 st->deinit_all = 0;
  94                 return 0;
  95         }
  96         return 0;
  97 }
  98
  99 const gchar *claws_ssl_get_cert_file(void)
 100 {
 101         const char *cert_files[]={
 102                 "/etc/pki/tls/certs/ca-bundle.crt",
 103                 "/etc/certs/ca-bundle.crt",
 104                 "/usr/share/ssl/certs/ca-bundle.crt",
 105                 "/etc/ssl/certs/ca-certificates.crt",
 106                 "/usr/local/ssl/certs/ca-bundle.crt",
 107                 "/etc/apache/ssl.crt/ca-bundle.crt",
 108                 "/usr/share/curl/curl-ca-bundle.crt",
 109                 "/usr/share/curl/curl-ca-bundle.crt",
 110                 "/usr/lib/ssl/cert.pem",
 111                 NULL};
 112         int i;
 113
 114         if (g_getenv("SSL_CERT_FILE"))
 115                 return g_getenv("SSL_CERT_FILE");
 116 #ifndef G_OS_WIN32
 117         for (i = 0; cert_files[i]; i++) {
 118                 if (is_file_exist(cert_files[i]))
 119                         return cert_files[i];
 120         }
 121         return NULL;
 122 #else
 123         const gchar *cert_file = NULL;
 124         if (cert_file == NULL)
 125                 cert_file = g_strconcat(DATAROOTDIR,
 126                                 G_DIR_SEPARATOR_S,
 127                                 "ca-certificates.crt",
 128                                 NULL);
 129         return cert_file;
 130 #endif
 131 }
 132
 133 const gchar *claws_ssl_get_cert_dir(void)
 134 {
 135         const char *cert_dirs[]={
 136                 "/etc/pki/tls/certs",
 137                 "/etc/certs",
 138                 "/usr/share/ssl/certs",
 139                 "/etc/ssl/certs",
 140                 "/usr/local/ssl/certs",
 141                 "/etc/apache/ssl.crt",
 142                 "/usr/share/curl",
 143                 "/usr/lib/ssl/certs",
 144                 NULL};
 145         int i;
 146
 147         if (g_getenv("SSL_CERT_DIR"))
 148                 return g_getenv("SSL_CERT_DIR");
 149 #ifndef G_OS_WIN32
 150         for (i = 0; cert_dirs[i]; i++) {
 151                 if (is_dir_exist(cert_dirs[i]))
 152                         return cert_dirs[i];
 153         }
 154         return NULL;
 155 #else
 156         return "put_what_s_needed_here";
 157 #endif
 158 }
 159
 160 void ssl_init(void)
 161 {
 162         gcry_control (GCRYCTL_SET_THREAD_CBS, &gcry_threads_pthread);
 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 int cipher_prio[] = { GNUTLS_CIPHER_AES_128_CBC,
 256                                 GNUTLS_CIPHER_3DES_CBC,
 257                                 GNUTLS_CIPHER_AES_256_CBC,
 258                                 GNUTLS_CIPHER_ARCFOUR_128, 0 };
 259         const int kx_prio[] = { GNUTLS_KX_DHE_RSA,
 260                            GNUTLS_KX_RSA,
 261                            GNUTLS_KX_DHE_DSS, 0 };
 262         const int mac_prio[] = { GNUTLS_MAC_SHA1,
 263                                 GNUTLS_MAC_MD5, 0 };
 264         const int proto_prio[] = { GNUTLS_TLS1,
 265                                   GNUTLS_SSL3, 0 };
 266         const gnutls_datum *raw_cert_list;
 267         unsigned int raw_cert_list_length;
 268         gnutls_x509_crt cert = NULL;
 269         guint status;
 270         gnutls_certificate_credentials_t xcred;
 271
 272         if (gnutls_certificate_allocate_credentials (&xcred) != 0)
 273                 return FALSE;
 274
 275         r = gnutls_init(&session, GNUTLS_CLIENT);
 276         if (session == NULL || r != 0)
 277                 return FALSE;
 278
 279         gnutls_set_default_priority(session);
 280         gnutls_protocol_set_priority (session, proto_prio);
 281         gnutls_cipher_set_priority (session, cipher_prio);
 282         gnutls_kx_set_priority (session, kx_prio);
 283         gnutls_mac_set_priority (session, mac_prio);
 284
 285         gnutls_credentials_set(session, GNUTLS_CRD_CERTIFICATE, xcred);
 286
 287         if (claws_ssl_get_cert_file()) {
 288                 r = gnutls_certificate_set_x509_trust_file(xcred, claws_ssl_get_cert_file(),  GNUTLS_X509_FMT_PEM);
 289                 if (r < 0)
 290                         g_warning("Can't read SSL_CERT_FILE %s: %s\n",
 291                                 claws_ssl_get_cert_file(),
 292                                 gnutls_strerror(r));
 293         } else {
 294                 debug_print("Can't find SSL ca-certificates file\n");
 295         }
 296         gnutls_certificate_set_verify_flags (xcred, GNUTLS_VERIFY_ALLOW_X509_V1_CA_CRT);
 297
 298         gnutls_transport_set_ptr(session, (gnutls_transport_ptr) sockinfo->sock);
 299         gnutls_session_set_ptr(session, sockinfo);
 300         gnutls_certificate_client_set_retrieve_function(xcred, gnutls_client_cert_cb);
 301
 302         gnutls_dh_set_prime_bits(session, 512);
 303
 304         if ((r = SSL_connect_nb(session)) < 0) {
 305                 g_warning("SSL connection failed (%s)", gnutls_strerror(r));
 306                 gnutls_certificate_free_credentials(xcred);
 307                 gnutls_deinit(session);
 308                 return FALSE;
 309         }
 310
 311         /* Get server's certificate (note: beware of dynamic allocation) */
 312         raw_cert_list = gnutls_certificate_get_peers(session, &raw_cert_list_length);
 313
 314         if (!raw_cert_list
 315         ||  gnutls_certificate_type_get(session) != GNUTLS_CRT_X509
 316         ||  (r = gnutls_x509_crt_init(&cert)) < 0
 317         ||  (r = gnutls_x509_crt_import(cert, &raw_cert_list[0], GNUTLS_X509_FMT_DER)) < 0) {
 318                 g_warning("cert get failure: %d %s\n", r, gnutls_strerror(r));
 319                 gnutls_certificate_free_credentials(xcred);
 320                 gnutls_deinit(session);
 321                 return FALSE;
 322         }
 323
 324         r = gnutls_certificate_verify_peers2(session, &status);
 325
 326         if (!ssl_certificate_check(cert, status, sockinfo->canonical_name, sockinfo->hostname, sockinfo->port)) {
 327                 gnutls_x509_crt_deinit(cert);
 328                 gnutls_certificate_free_credentials(xcred);
 329                 gnutls_deinit(session);
 330                 return FALSE;
 331         }
 332
 333         gnutls_x509_crt_deinit(cert);
 334
 335         sockinfo->ssl = session;
 336         sockinfo->xcred = xcred;
 337         return TRUE;
 338 }
 339
 340 void ssl_done_socket(SockInfo *sockinfo)
 341 {
 342         if (sockinfo && sockinfo->ssl) {
 343                 gnutls_certificate_free_credentials(sockinfo->xcred);
 344                 gnutls_deinit(sockinfo->ssl);
 345                 if (sockinfo->client_crt)
 346                         gnutls_x509_crt_deinit(sockinfo->client_crt);
 347                 if (sockinfo->client_key)
 348                         gnutls_x509_privkey_deinit(sockinfo->client_key);
 349                 sockinfo->client_key = NULL;
 350                 sockinfo->client_crt = NULL;
 351                 sockinfo->ssl = NULL;
 352         }
 353 }
 354
 355 #endif /* USE_GNUTLS */