libavformat/tls_gnutls.c
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 /*
  * TLS/SSL Protocol
  * Copyright (c) 2011 Martin Storsjo
  *
  * This file is part of FFmpeg.
  *
  * FFmpeg is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
  *
  * FFmpeg is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public
  * License along with FFmpeg; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
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 #include <errno.h>
 
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 #include <gnutls/gnutls.h>
 #include <gnutls/x509.h>
 
 #include "avformat.h"
 #include "internal.h"
 #include "network.h"
 #include "os_support.h"
 #include "url.h"
 #include "tls.h"
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 #include "libavcodec/internal.h"
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 #include "libavutil/avstring.h"
 #include "libavutil/opt.h"
 #include "libavutil/parseutils.h"
 
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 #if HAVE_THREADS && GNUTLS_VERSION_NUMBER <= 0x020b00
 #include <gcrypt.h>
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 #include "libavutil/thread.h"
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 GCRY_THREAD_OPTION_PTHREAD_IMPL;
 #endif
 
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 typedef struct TLSContext {
     const AVClass *class;
     TLSShared tls_shared;
     gnutls_session_t session;
     gnutls_certificate_credentials_t cred;
     int need_shutdown;
 } TLSContext;
 
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 void ff_gnutls_init(void)
 {
     avpriv_lock_avformat();
 #if HAVE_THREADS && GNUTLS_VERSION_NUMBER < 0x020b00
     if (gcry_control(GCRYCTL_ANY_INITIALIZATION_P) == 0)
         gcry_control(GCRYCTL_SET_THREAD_CBS, &gcry_threads_pthread);
 #endif
     gnutls_global_init();
     avpriv_unlock_avformat();
 }
 
 void ff_gnutls_deinit(void)
 {
     avpriv_lock_avformat();
     gnutls_global_deinit();
     avpriv_unlock_avformat();
 }
 
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 static int print_tls_error(URLContext *h, int ret)
 {
     switch (ret) {
     case GNUTLS_E_AGAIN:
     case GNUTLS_E_INTERRUPTED:
         break;
     case GNUTLS_E_WARNING_ALERT_RECEIVED:
         av_log(h, AV_LOG_WARNING, "%s\n", gnutls_strerror(ret));
         break;
     default:
         av_log(h, AV_LOG_ERROR, "%s\n", gnutls_strerror(ret));
         break;
     }
     return AVERROR(EIO);
 }
 
 static int tls_close(URLContext *h)
 {
     TLSContext *c = h->priv_data;
     if (c->need_shutdown)
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         gnutls_bye(c->session, GNUTLS_SHUT_WR);
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     if (c->session)
         gnutls_deinit(c->session);
     if (c->cred)
         gnutls_certificate_free_credentials(c->cred);
     if (c->tls_shared.tcp)
         ffurl_close(c->tls_shared.tcp);
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     ff_gnutls_deinit();
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     return 0;
 }
 
 static ssize_t gnutls_url_pull(gnutls_transport_ptr_t transport,
                                void *buf, size_t len)
 {
     URLContext *h = (URLContext*) transport;
     int ret = ffurl_read(h, buf, len);
     if (ret >= 0)
         return ret;
     if (ret == AVERROR_EXIT)
         return 0;
     errno = EIO;
     return -1;
 }
 
 static ssize_t gnutls_url_push(gnutls_transport_ptr_t transport,
                                const void *buf, size_t len)
 {
     URLContext *h = (URLContext*) transport;
     int ret = ffurl_write(h, buf, len);
     if (ret >= 0)
         return ret;
     if (ret == AVERROR_EXIT)
         return 0;
     errno = EIO;
     return -1;
 }
 
 static int tls_open(URLContext *h, const char *uri, int flags, AVDictionary **options)
 {
     TLSContext *p = h->priv_data;
     TLSShared *c = &p->tls_shared;
     int ret;
 
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     ff_gnutls_init();
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     if ((ret = ff_tls_open_underlying(c, h, uri, options)) < 0)
         goto fail;
 
     gnutls_init(&p->session, c->listen ? GNUTLS_SERVER : GNUTLS_CLIENT);
     if (!c->listen && !c->numerichost)
         gnutls_server_name_set(p->session, GNUTLS_NAME_DNS, c->host, strlen(c->host));
     gnutls_certificate_allocate_credentials(&p->cred);
     if (c->ca_file) {
         ret = gnutls_certificate_set_x509_trust_file(p->cred, c->ca_file, GNUTLS_X509_FMT_PEM);
         if (ret < 0)
             av_log(h, AV_LOG_ERROR, "%s\n", gnutls_strerror(ret));
     }
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 #if GNUTLS_VERSION_NUMBER >= 0x030020
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     else
         gnutls_certificate_set_x509_system_trust(p->cred);
 #endif
     gnutls_certificate_set_verify_flags(p->cred, c->verify ?
                                         GNUTLS_VERIFY_ALLOW_X509_V1_CA_CRT : 0);
     if (c->cert_file && c->key_file) {
         ret = gnutls_certificate_set_x509_key_file(p->cred,
                                                    c->cert_file, c->key_file,
                                                    GNUTLS_X509_FMT_PEM);
         if (ret < 0) {
             av_log(h, AV_LOG_ERROR,
                    "Unable to set cert/key files %s and %s: %s\n",
                    c->cert_file, c->key_file, gnutls_strerror(ret));
             ret = AVERROR(EIO);
             goto fail;
         }
     } else if (c->cert_file || c->key_file)
         av_log(h, AV_LOG_ERROR, "cert and key required\n");
     gnutls_credentials_set(p->session, GNUTLS_CRD_CERTIFICATE, p->cred);
     gnutls_transport_set_pull_function(p->session, gnutls_url_pull);
     gnutls_transport_set_push_function(p->session, gnutls_url_push);
     gnutls_transport_set_ptr(p->session, c->tcp);
     gnutls_priority_set_direct(p->session, "NORMAL", NULL);
     ret = gnutls_handshake(p->session);
     if (ret) {
         ret = print_tls_error(h, ret);
         goto fail;
     }
     p->need_shutdown = 1;
     if (c->verify) {
         unsigned int status, cert_list_size;
         gnutls_x509_crt_t cert;
         const gnutls_datum_t *cert_list;
         if ((ret = gnutls_certificate_verify_peers2(p->session, &status)) < 0) {
             av_log(h, AV_LOG_ERROR, "Unable to verify peer certificate: %s\n",
                                     gnutls_strerror(ret));
             ret = AVERROR(EIO);
             goto fail;
         }
         if (status & GNUTLS_CERT_INVALID) {
             av_log(h, AV_LOG_ERROR, "Peer certificate failed verification\n");
             ret = AVERROR(EIO);
             goto fail;
         }
         if (gnutls_certificate_type_get(p->session) != GNUTLS_CRT_X509) {
             av_log(h, AV_LOG_ERROR, "Unsupported certificate type\n");
             ret = AVERROR(EIO);
             goto fail;
         }
         gnutls_x509_crt_init(&cert);
         cert_list = gnutls_certificate_get_peers(p->session, &cert_list_size);
         gnutls_x509_crt_import(cert, cert_list, GNUTLS_X509_FMT_DER);
         ret = gnutls_x509_crt_check_hostname(cert, c->host);
         gnutls_x509_crt_deinit(cert);
         if (!ret) {
             av_log(h, AV_LOG_ERROR,
                    "The certificate's owner does not match hostname %s\n", c->host);
             ret = AVERROR(EIO);
             goto fail;
         }
     }
 
     return 0;
 fail:
     tls_close(h);
     return ret;
 }
 
 static int tls_read(URLContext *h, uint8_t *buf, int size)
 {
     TLSContext *c = h->priv_data;
     int ret = gnutls_record_recv(c->session, buf, size);
     if (ret > 0)
         return ret;
     if (ret == 0)
         return AVERROR_EOF;
     return print_tls_error(h, ret);
 }
 
 static int tls_write(URLContext *h, const uint8_t *buf, int size)
 {
     TLSContext *c = h->priv_data;
     int ret = gnutls_record_send(c->session, buf, size);
     if (ret > 0)
         return ret;
     if (ret == 0)
         return AVERROR_EOF;
     return print_tls_error(h, ret);
 }
 
 static const AVOption options[] = {
     TLS_COMMON_OPTIONS(TLSContext, tls_shared),
     { NULL }
 };
 
 static const AVClass tls_class = {
     .class_name = "tls",
     .item_name  = av_default_item_name,
     .option     = options,
     .version    = LIBAVUTIL_VERSION_INT,
 };
 
 URLProtocol ff_tls_gnutls_protocol = {
     .name           = "tls",
     .url_open2      = tls_open,
     .url_read       = tls_read,
     .url_write      = tls_write,
     .url_close      = tls_close,
     .priv_data_size = sizeof(TLSContext),
     .flags          = URL_PROTOCOL_FLAG_NETWORK,
     .priv_data_class = &tls_class,
 };