git.sesse.net Git - ffmpeg/blob - libavformat/tls_gnutls.c

   1 /*
   2  * TLS/SSL Protocol
   3  * Copyright (c) 2011 Martin Storsjo
   4  *
   5  * This file is part of FFmpeg.
   6  *
   7  * FFmpeg is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * FFmpeg is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with FFmpeg; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21
  22 #include <errno.h>
  23
  24 #include <gnutls/gnutls.h>
  25 #include <gnutls/x509.h>
  26
  27 #include "avformat.h"
  28 #include "internal.h"
  29 #include "network.h"
  30 #include "os_support.h"
  31 #include "url.h"
  32 #include "tls.h"
  33 #include "libavcodec/internal.h"
  34 #include "libavutil/avstring.h"
  35 #include "libavutil/opt.h"
  36 #include "libavutil/parseutils.h"
  37
  38 #ifndef GNUTLS_VERSION_NUMBER
  39 #define GNUTLS_VERSION_NUMBER LIBGNUTLS_VERSION_NUMBER
  40 #endif
  41
  42 #if HAVE_THREADS && GNUTLS_VERSION_NUMBER <= 0x020b00
  43 #include <gcrypt.h>
  44 #include "libavutil/thread.h"
  45 GCRY_THREAD_OPTION_PTHREAD_IMPL;
  46 #endif
  47
  48 typedef struct TLSContext {
  49     const AVClass *class;
  50     TLSShared tls_shared;
  51     gnutls_session_t session;
  52     gnutls_certificate_credentials_t cred;
  53     int need_shutdown;
  54 } TLSContext;
  55
  56 void ff_gnutls_init(void)
  57 {
  58     ff_lock_avformat();
  59 #if HAVE_THREADS && GNUTLS_VERSION_NUMBER < 0x020b00
  60     if (gcry_control(GCRYCTL_ANY_INITIALIZATION_P) == 0)
  61         gcry_control(GCRYCTL_SET_THREAD_CBS, &gcry_threads_pthread);
  62 #endif
  63     gnutls_global_init();
  64     ff_unlock_avformat();
  65 }
  66
  67 void ff_gnutls_deinit(void)
  68 {
  69     ff_lock_avformat();
  70     gnutls_global_deinit();
  71     ff_unlock_avformat();
  72 }
  73
  74 static int print_tls_error(URLContext *h, int ret)
  75 {
  76     switch (ret) {
  77     case GNUTLS_E_AGAIN:
  78         return AVERROR(EAGAIN);
  79     case GNUTLS_E_INTERRUPTED:
  80 #ifdef GNUTLS_E_PREMATURE_TERMINATION
  81     case GNUTLS_E_PREMATURE_TERMINATION:
  82 #endif
  83         break;
  84     case GNUTLS_E_WARNING_ALERT_RECEIVED:
  85         av_log(h, AV_LOG_WARNING, "%s\n", gnutls_strerror(ret));
  86         break;
  87     default:
  88         av_log(h, AV_LOG_ERROR, "%s\n", gnutls_strerror(ret));
  89         break;
  90     }
  91     return AVERROR(EIO);
  92 }
  93
  94 static int tls_close(URLContext *h)
  95 {
  96     TLSContext *c = h->priv_data;
  97     if (c->need_shutdown)
  98         gnutls_bye(c->session, GNUTLS_SHUT_WR);
  99     if (c->session)
 100         gnutls_deinit(c->session);
 101     if (c->cred)
 102         gnutls_certificate_free_credentials(c->cred);
 103     if (c->tls_shared.tcp)
 104         ffurl_close(c->tls_shared.tcp);
 105     ff_gnutls_deinit();
 106     return 0;
 107 }
 108
 109 static ssize_t gnutls_url_pull(gnutls_transport_ptr_t transport,
 110                                void *buf, size_t len)
 111 {
 112     URLContext *h = (URLContext*) transport;
 113     int ret = ffurl_read(h, buf, len);
 114     if (ret >= 0)
 115         return ret;
 116     if (ret == AVERROR_EXIT)
 117         return 0;
 118     if (ret == AVERROR(EAGAIN))
 119         errno = EAGAIN;
 120     else
 121         errno = EIO;
 122     return -1;
 123 }
 124
 125 static ssize_t gnutls_url_push(gnutls_transport_ptr_t transport,
 126                                const void *buf, size_t len)
 127 {
 128     URLContext *h = (URLContext*) transport;
 129     int ret = ffurl_write(h, buf, len);
 130     if (ret >= 0)
 131         return ret;
 132     if (ret == AVERROR_EXIT)
 133         return 0;
 134     if (ret == AVERROR(EAGAIN))
 135         errno = EAGAIN;
 136     else
 137         errno = EIO;
 138     return -1;
 139 }
 140
 141 static int tls_open(URLContext *h, const char *uri, int flags, AVDictionary **options)
 142 {
 143     TLSContext *p = h->priv_data;
 144     TLSShared *c = &p->tls_shared;
 145     int ret;
 146
 147     ff_gnutls_init();
 148
 149     if ((ret = ff_tls_open_underlying(c, h, uri, options)) < 0)
 150         goto fail;
 151
 152     gnutls_init(&p->session, c->listen ? GNUTLS_SERVER : GNUTLS_CLIENT);
 153     if (!c->listen && !c->numerichost)
 154         gnutls_server_name_set(p->session, GNUTLS_NAME_DNS, c->host, strlen(c->host));
 155     gnutls_certificate_allocate_credentials(&p->cred);
 156     if (c->ca_file) {
 157         ret = gnutls_certificate_set_x509_trust_file(p->cred, c->ca_file, GNUTLS_X509_FMT_PEM);
 158         if (ret < 0)
 159             av_log(h, AV_LOG_ERROR, "%s\n", gnutls_strerror(ret));
 160     }
 161 #if GNUTLS_VERSION_NUMBER >= 0x030020
 162     else
 163         gnutls_certificate_set_x509_system_trust(p->cred);
 164 #endif
 165     gnutls_certificate_set_verify_flags(p->cred, c->verify ?
 166                                         GNUTLS_VERIFY_ALLOW_X509_V1_CA_CRT : 0);
 167     if (c->cert_file && c->key_file) {
 168         ret = gnutls_certificate_set_x509_key_file(p->cred,
 169                                                    c->cert_file, c->key_file,
 170                                                    GNUTLS_X509_FMT_PEM);
 171         if (ret < 0) {
 172             av_log(h, AV_LOG_ERROR,
 173                    "Unable to set cert/key files %s and %s: %s\n",
 174                    c->cert_file, c->key_file, gnutls_strerror(ret));
 175             ret = AVERROR(EIO);
 176             goto fail;
 177         }
 178     } else if (c->cert_file || c->key_file)
 179         av_log(h, AV_LOG_ERROR, "cert and key required\n");
 180     gnutls_credentials_set(p->session, GNUTLS_CRD_CERTIFICATE, p->cred);
 181     gnutls_transport_set_pull_function(p->session, gnutls_url_pull);
 182     gnutls_transport_set_push_function(p->session, gnutls_url_push);
 183     gnutls_transport_set_ptr(p->session, c->tcp);
 184     gnutls_priority_set_direct(p->session, "NORMAL", NULL);
 185     do {
 186         ret = gnutls_handshake(p->session);
 187         if (gnutls_error_is_fatal(ret)) {
 188             ret = print_tls_error(h, ret);
 189             goto fail;
 190         }
 191     } while (ret);
 192     p->need_shutdown = 1;
 193     if (c->verify) {
 194         unsigned int status, cert_list_size;
 195         gnutls_x509_crt_t cert;
 196         const gnutls_datum_t *cert_list;
 197         if ((ret = gnutls_certificate_verify_peers2(p->session, &status)) < 0) {
 198             av_log(h, AV_LOG_ERROR, "Unable to verify peer certificate: %s\n",
 199                                     gnutls_strerror(ret));
 200             ret = AVERROR(EIO);
 201             goto fail;
 202         }
 203         if (status & GNUTLS_CERT_INVALID) {
 204             av_log(h, AV_LOG_ERROR, "Peer certificate failed verification\n");
 205             ret = AVERROR(EIO);
 206             goto fail;
 207         }
 208         if (gnutls_certificate_type_get(p->session) != GNUTLS_CRT_X509) {
 209             av_log(h, AV_LOG_ERROR, "Unsupported certificate type\n");
 210             ret = AVERROR(EIO);
 211             goto fail;
 212         }
 213         gnutls_x509_crt_init(&cert);
 214         cert_list = gnutls_certificate_get_peers(p->session, &cert_list_size);
 215         gnutls_x509_crt_import(cert, cert_list, GNUTLS_X509_FMT_DER);
 216         ret = gnutls_x509_crt_check_hostname(cert, c->host);
 217         gnutls_x509_crt_deinit(cert);
 218         if (!ret) {
 219             av_log(h, AV_LOG_ERROR,
 220                    "The certificate's owner does not match hostname %s\n", c->host);
 221             ret = AVERROR(EIO);
 222             goto fail;
 223         }
 224     }
 225
 226     return 0;
 227 fail:
 228     tls_close(h);
 229     return ret;
 230 }
 231
 232 static int tls_read(URLContext *h, uint8_t *buf, int size)
 233 {
 234     TLSContext *c = h->priv_data;
 235     int ret;
 236     // Set or clear the AVIO_FLAG_NONBLOCK on c->tls_shared.tcp
 237     c->tls_shared.tcp->flags &= ~AVIO_FLAG_NONBLOCK;
 238     c->tls_shared.tcp->flags |= h->flags & AVIO_FLAG_NONBLOCK;
 239     ret = gnutls_record_recv(c->session, buf, size);
 240     if (ret > 0)
 241         return ret;
 242     if (ret == 0)
 243         return AVERROR_EOF;
 244     return print_tls_error(h, ret);
 245 }
 246
 247 static int tls_write(URLContext *h, const uint8_t *buf, int size)
 248 {
 249     TLSContext *c = h->priv_data;
 250     int ret;
 251     // Set or clear the AVIO_FLAG_NONBLOCK on c->tls_shared.tcp
 252     c->tls_shared.tcp->flags &= ~AVIO_FLAG_NONBLOCK;
 253     c->tls_shared.tcp->flags |= h->flags & AVIO_FLAG_NONBLOCK;
 254     ret = gnutls_record_send(c->session, buf, size);
 255     if (ret > 0)
 256         return ret;
 257     if (ret == 0)
 258         return AVERROR_EOF;
 259     return print_tls_error(h, ret);
 260 }
 261
 262 static int tls_get_file_handle(URLContext *h)
 263 {
 264     TLSContext *c = h->priv_data;
 265     return ffurl_get_file_handle(c->tls_shared.tcp);
 266 }
 267
 268 static const AVOption options[] = {
 269     TLS_COMMON_OPTIONS(TLSContext, tls_shared),
 270     { NULL }
 271 };
 272
 273 static const AVClass tls_class = {
 274     .class_name = "tls",
 275     .item_name  = av_default_item_name,
 276     .option     = options,
 277     .version    = LIBAVUTIL_VERSION_INT,
 278 };
 279
 280 const URLProtocol ff_tls_protocol = {
 281     .name           = "tls",
 282     .url_open2      = tls_open,
 283     .url_read       = tls_read,
 284     .url_write      = tls_write,
 285     .url_close      = tls_close,
 286     .url_get_file_handle = tls_get_file_handle,
 287     .priv_data_size = sizeof(TLSContext),
 288     .flags          = URL_PROTOCOL_FLAG_NETWORK,
 289     .priv_data_class = &tls_class,
 290 };