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     int io_err;
  55 } TLSContext;
  56
  57 void ff_gnutls_init(void)
  58 {
  59     ff_lock_avformat();
  60 #if HAVE_THREADS && GNUTLS_VERSION_NUMBER < 0x020b00
  61     if (gcry_control(GCRYCTL_ANY_INITIALIZATION_P) == 0)
  62         gcry_control(GCRYCTL_SET_THREAD_CBS, &gcry_threads_pthread);
  63 #endif
  64     gnutls_global_init();
  65     ff_unlock_avformat();
  66 }
  67
  68 void ff_gnutls_deinit(void)
  69 {
  70     ff_lock_avformat();
  71     gnutls_global_deinit();
  72     ff_unlock_avformat();
  73 }
  74
  75 static int print_tls_error(URLContext *h, int ret)
  76 {
  77     TLSContext *c = h->priv_data;
  78     switch (ret) {
  79     case GNUTLS_E_AGAIN:
  80         return AVERROR(EAGAIN);
  81     case GNUTLS_E_INTERRUPTED:
  82 #ifdef GNUTLS_E_PREMATURE_TERMINATION
  83     case GNUTLS_E_PREMATURE_TERMINATION:
  84 #endif
  85         break;
  86     case GNUTLS_E_WARNING_ALERT_RECEIVED:
  87         av_log(h, AV_LOG_WARNING, "%s\n", gnutls_strerror(ret));
  88         break;
  89     default:
  90         av_log(h, AV_LOG_ERROR, "%s\n", gnutls_strerror(ret));
  91         break;
  92     }
  93     if (c->io_err) {
  94         av_log(h, AV_LOG_ERROR, "IO error: %s\n", av_err2str(c->io_err));
  95         ret = c->io_err;
  96         c->io_err = 0;
  97         return ret;
  98     }
  99     return AVERROR(EIO);
 100 }
 101
 102 static int tls_close(URLContext *h)
 103 {
 104     TLSContext *c = h->priv_data;
 105     if (c->need_shutdown)
 106         gnutls_bye(c->session, GNUTLS_SHUT_WR);
 107     if (c->session)
 108         gnutls_deinit(c->session);
 109     if (c->cred)
 110         gnutls_certificate_free_credentials(c->cred);
 111     ffurl_closep(&c->tls_shared.tcp);
 112     ff_gnutls_deinit();
 113     return 0;
 114 }
 115
 116 static ssize_t gnutls_url_pull(gnutls_transport_ptr_t transport,
 117                                void *buf, size_t len)
 118 {
 119     TLSContext *c = (TLSContext*) transport;
 120     int ret = ffurl_read(c->tls_shared.tcp, buf, len);
 121     if (ret >= 0)
 122         return ret;
 123     if (ret == AVERROR_EXIT)
 124         return 0;
 125     if (ret == AVERROR(EAGAIN)) {
 126         errno = EAGAIN;
 127     } else {
 128         errno = EIO;
 129         c->io_err = ret;
 130     }
 131     return -1;
 132 }
 133
 134 static ssize_t gnutls_url_push(gnutls_transport_ptr_t transport,
 135                                const void *buf, size_t len)
 136 {
 137     TLSContext *c = (TLSContext*) transport;
 138     int ret = ffurl_write(c->tls_shared.tcp, buf, len);
 139     if (ret >= 0)
 140         return ret;
 141     if (ret == AVERROR_EXIT)
 142         return 0;
 143     if (ret == AVERROR(EAGAIN)) {
 144         errno = EAGAIN;
 145     } else {
 146         errno = EIO;
 147         c->io_err = ret;
 148     }
 149     return -1;
 150 }
 151
 152 static int tls_open(URLContext *h, const char *uri, int flags, AVDictionary **options)
 153 {
 154     TLSContext *p = h->priv_data;
 155     TLSShared *c = &p->tls_shared;
 156     int ret;
 157
 158     ff_gnutls_init();
 159
 160     if ((ret = ff_tls_open_underlying(c, h, uri, options)) < 0)
 161         goto fail;
 162
 163     gnutls_init(&p->session, c->listen ? GNUTLS_SERVER : GNUTLS_CLIENT);
 164     if (!c->listen && !c->numerichost)
 165         gnutls_server_name_set(p->session, GNUTLS_NAME_DNS, c->host, strlen(c->host));
 166     gnutls_certificate_allocate_credentials(&p->cred);
 167     if (c->ca_file) {
 168         ret = gnutls_certificate_set_x509_trust_file(p->cred, c->ca_file, GNUTLS_X509_FMT_PEM);
 169         if (ret < 0)
 170             av_log(h, AV_LOG_ERROR, "%s\n", gnutls_strerror(ret));
 171     }
 172 #if GNUTLS_VERSION_NUMBER >= 0x030020
 173     else
 174         gnutls_certificate_set_x509_system_trust(p->cred);
 175 #endif
 176     gnutls_certificate_set_verify_flags(p->cred, c->verify ?
 177                                         GNUTLS_VERIFY_ALLOW_X509_V1_CA_CRT : 0);
 178     if (c->cert_file && c->key_file) {
 179         ret = gnutls_certificate_set_x509_key_file(p->cred,
 180                                                    c->cert_file, c->key_file,
 181                                                    GNUTLS_X509_FMT_PEM);
 182         if (ret < 0) {
 183             av_log(h, AV_LOG_ERROR,
 184                    "Unable to set cert/key files %s and %s: %s\n",
 185                    c->cert_file, c->key_file, gnutls_strerror(ret));
 186             ret = AVERROR(EIO);
 187             goto fail;
 188         }
 189     } else if (c->cert_file || c->key_file)
 190         av_log(h, AV_LOG_ERROR, "cert and key required\n");
 191     gnutls_credentials_set(p->session, GNUTLS_CRD_CERTIFICATE, p->cred);
 192     gnutls_transport_set_pull_function(p->session, gnutls_url_pull);
 193     gnutls_transport_set_push_function(p->session, gnutls_url_push);
 194     gnutls_transport_set_ptr(p->session, p);
 195     gnutls_priority_set_direct(p->session, "NORMAL", NULL);
 196     do {
 197         if (ff_check_interrupt(&h->interrupt_callback)) {
 198             ret = AVERROR_EXIT;
 199             goto fail;
 200         }
 201
 202         ret = gnutls_handshake(p->session);
 203         if (gnutls_error_is_fatal(ret)) {
 204             ret = print_tls_error(h, ret);
 205             goto fail;
 206         }
 207     } while (ret);
 208     p->need_shutdown = 1;
 209     if (c->verify) {
 210         unsigned int status, cert_list_size;
 211         gnutls_x509_crt_t cert;
 212         const gnutls_datum_t *cert_list;
 213         if ((ret = gnutls_certificate_verify_peers2(p->session, &status)) < 0) {
 214             av_log(h, AV_LOG_ERROR, "Unable to verify peer certificate: %s\n",
 215                                     gnutls_strerror(ret));
 216             ret = AVERROR(EIO);
 217             goto fail;
 218         }
 219         if (status & GNUTLS_CERT_INVALID) {
 220             av_log(h, AV_LOG_ERROR, "Peer certificate failed verification\n");
 221             ret = AVERROR(EIO);
 222             goto fail;
 223         }
 224         if (gnutls_certificate_type_get(p->session) != GNUTLS_CRT_X509) {
 225             av_log(h, AV_LOG_ERROR, "Unsupported certificate type\n");
 226             ret = AVERROR(EIO);
 227             goto fail;
 228         }
 229         gnutls_x509_crt_init(&cert);
 230         cert_list = gnutls_certificate_get_peers(p->session, &cert_list_size);
 231         gnutls_x509_crt_import(cert, cert_list, GNUTLS_X509_FMT_DER);
 232         ret = gnutls_x509_crt_check_hostname(cert, c->host);
 233         gnutls_x509_crt_deinit(cert);
 234         if (!ret) {
 235             av_log(h, AV_LOG_ERROR,
 236                    "The certificate's owner does not match hostname %s\n", c->host);
 237             ret = AVERROR(EIO);
 238             goto fail;
 239         }
 240     }
 241
 242     return 0;
 243 fail:
 244     tls_close(h);
 245     return ret;
 246 }
 247
 248 static int tls_read(URLContext *h, uint8_t *buf, int size)
 249 {
 250     TLSContext *c = h->priv_data;
 251     int ret;
 252     // Set or clear the AVIO_FLAG_NONBLOCK on c->tls_shared.tcp
 253     c->tls_shared.tcp->flags &= ~AVIO_FLAG_NONBLOCK;
 254     c->tls_shared.tcp->flags |= h->flags & AVIO_FLAG_NONBLOCK;
 255     ret = gnutls_record_recv(c->session, buf, size);
 256     if (ret > 0)
 257         return ret;
 258     if (ret == 0)
 259         return AVERROR_EOF;
 260     return print_tls_error(h, ret);
 261 }
 262
 263 static int tls_write(URLContext *h, const uint8_t *buf, int size)
 264 {
 265     TLSContext *c = h->priv_data;
 266     int ret;
 267     // Set or clear the AVIO_FLAG_NONBLOCK on c->tls_shared.tcp
 268     c->tls_shared.tcp->flags &= ~AVIO_FLAG_NONBLOCK;
 269     c->tls_shared.tcp->flags |= h->flags & AVIO_FLAG_NONBLOCK;
 270     ret = gnutls_record_send(c->session, buf, size);
 271     if (ret > 0)
 272         return ret;
 273     if (ret == 0)
 274         return AVERROR_EOF;
 275     return print_tls_error(h, ret);
 276 }
 277
 278 static int tls_get_file_handle(URLContext *h)
 279 {
 280     TLSContext *c = h->priv_data;
 281     return ffurl_get_file_handle(c->tls_shared.tcp);
 282 }
 283
 284 static int tls_get_short_seek(URLContext *h)
 285 {
 286     TLSContext *s = h->priv_data;
 287     return ffurl_get_short_seek(s->tls_shared.tcp);
 288 }
 289
 290 static const AVOption options[] = {
 291     TLS_COMMON_OPTIONS(TLSContext, tls_shared),
 292     { NULL }
 293 };
 294
 295 static const AVClass tls_class = {
 296     .class_name = "tls",
 297     .item_name  = av_default_item_name,
 298     .option     = options,
 299     .version    = LIBAVUTIL_VERSION_INT,
 300 };
 301
 302 const URLProtocol ff_tls_protocol = {
 303     .name           = "tls",
 304     .url_open2      = tls_open,
 305     .url_read       = tls_read,
 306     .url_write      = tls_write,
 307     .url_close      = tls_close,
 308     .url_get_file_handle = tls_get_file_handle,
 309     .url_get_short_seek  = tls_get_short_seek,
 310     .priv_data_size = sizeof(TLSContext),
 311     .flags          = URL_PROTOCOL_FLAG_NETWORK,
 312     .priv_data_class = &tls_class,
 313 };