tls: Hide backend implementation details from users
[libav.git] / libavformat / tls_gnutls.c
1 /*
2 * TLS/SSL Protocol
3 * Copyright (c) 2011 Martin Storsjo
4 *
5 * This file is part of Libav.
6 *
7 * Libav 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 * Libav 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 Libav; 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 typedef struct TLSContext {
39 const AVClass *class;
40 TLSShared tls_shared;
41 gnutls_session_t session;
42 gnutls_certificate_credentials_t cred;
43 int need_shutdown;
44 } TLSContext;
45
46 void ff_gnutls_init(void)
47 {
48 avpriv_lock_avformat();
49 gnutls_global_init();
50 avpriv_unlock_avformat();
51 }
52
53 void ff_gnutls_deinit(void)
54 {
55 avpriv_lock_avformat();
56 gnutls_global_deinit();
57 avpriv_unlock_avformat();
58 }
59
60 static int print_tls_error(URLContext *h, int ret)
61 {
62 switch (ret) {
63 case GNUTLS_E_AGAIN:
64 case GNUTLS_E_INTERRUPTED:
65 break;
66 case GNUTLS_E_WARNING_ALERT_RECEIVED:
67 av_log(h, AV_LOG_WARNING, "%s\n", gnutls_strerror(ret));
68 break;
69 default:
70 av_log(h, AV_LOG_ERROR, "%s\n", gnutls_strerror(ret));
71 break;
72 }
73 return AVERROR(EIO);
74 }
75
76 static int tls_close(URLContext *h)
77 {
78 TLSContext *c = h->priv_data;
79 if (c->need_shutdown)
80 gnutls_bye(c->session, GNUTLS_SHUT_WR);
81 if (c->session)
82 gnutls_deinit(c->session);
83 if (c->cred)
84 gnutls_certificate_free_credentials(c->cred);
85 if (c->tls_shared.tcp)
86 ffurl_close(c->tls_shared.tcp);
87 ff_gnutls_deinit();
88 return 0;
89 }
90
91 static ssize_t gnutls_url_pull(gnutls_transport_ptr_t transport,
92 void *buf, size_t len)
93 {
94 URLContext *h = (URLContext*) transport;
95 int ret = ffurl_read(h, buf, len);
96 if (ret >= 0)
97 return ret;
98 if (ret == AVERROR_EXIT)
99 return 0;
100 errno = EIO;
101 return -1;
102 }
103
104 static ssize_t gnutls_url_push(gnutls_transport_ptr_t transport,
105 const void *buf, size_t len)
106 {
107 URLContext *h = (URLContext*) transport;
108 int ret = ffurl_write(h, buf, len);
109 if (ret >= 0)
110 return ret;
111 if (ret == AVERROR_EXIT)
112 return 0;
113 errno = EIO;
114 return -1;
115 }
116
117 static int tls_open(URLContext *h, const char *uri, int flags, AVDictionary **options)
118 {
119 TLSContext *p = h->priv_data;
120 TLSShared *c = &p->tls_shared;
121 int ret;
122
123 ff_gnutls_init();
124
125 if ((ret = ff_tls_open_underlying(c, h, uri, options)) < 0)
126 goto fail;
127
128 gnutls_init(&p->session, c->listen ? GNUTLS_SERVER : GNUTLS_CLIENT);
129 if (!c->listen && !c->numerichost)
130 gnutls_server_name_set(p->session, GNUTLS_NAME_DNS, c->host, strlen(c->host));
131 gnutls_certificate_allocate_credentials(&p->cred);
132 if (c->ca_file)
133 gnutls_certificate_set_x509_trust_file(p->cred, c->ca_file, GNUTLS_X509_FMT_PEM);
134 #if GNUTLS_VERSION_MAJOR >= 3
135 else
136 gnutls_certificate_set_x509_system_trust(p->cred);
137 #endif
138 gnutls_certificate_set_verify_flags(p->cred, c->verify ?
139 GNUTLS_VERIFY_ALLOW_X509_V1_CA_CRT : 0);
140 if (c->cert_file && c->key_file) {
141 ret = gnutls_certificate_set_x509_key_file(p->cred,
142 c->cert_file, c->key_file,
143 GNUTLS_X509_FMT_PEM);
144 if (ret < 0) {
145 av_log(h, AV_LOG_ERROR,
146 "Unable to set cert/key files %s and %s: %s\n",
147 c->cert_file, c->key_file, gnutls_strerror(ret));
148 ret = AVERROR(EIO);
149 goto fail;
150 }
151 }
152 gnutls_credentials_set(p->session, GNUTLS_CRD_CERTIFICATE, p->cred);
153 gnutls_transport_set_pull_function(p->session, gnutls_url_pull);
154 gnutls_transport_set_push_function(p->session, gnutls_url_push);
155 gnutls_transport_set_ptr(p->session, c->tcp);
156 gnutls_priority_set_direct(p->session, "NORMAL", NULL);
157 ret = gnutls_handshake(p->session);
158 if (ret) {
159 ret = print_tls_error(h, ret);
160 goto fail;
161 }
162 p->need_shutdown = 1;
163 if (c->verify) {
164 unsigned int status, cert_list_size;
165 gnutls_x509_crt_t cert;
166 const gnutls_datum_t *cert_list;
167 if ((ret = gnutls_certificate_verify_peers2(p->session, &status)) < 0) {
168 av_log(h, AV_LOG_ERROR, "Unable to verify peer certificate: %s\n",
169 gnutls_strerror(ret));
170 ret = AVERROR(EIO);
171 goto fail;
172 }
173 if (status & GNUTLS_CERT_INVALID) {
174 av_log(h, AV_LOG_ERROR, "Peer certificate failed verification\n");
175 ret = AVERROR(EIO);
176 goto fail;
177 }
178 if (gnutls_certificate_type_get(p->session) != GNUTLS_CRT_X509) {
179 av_log(h, AV_LOG_ERROR, "Unsupported certificate type\n");
180 ret = AVERROR(EIO);
181 goto fail;
182 }
183 gnutls_x509_crt_init(&cert);
184 cert_list = gnutls_certificate_get_peers(p->session, &cert_list_size);
185 gnutls_x509_crt_import(cert, cert_list, GNUTLS_X509_FMT_DER);
186 ret = gnutls_x509_crt_check_hostname(cert, c->host);
187 gnutls_x509_crt_deinit(cert);
188 if (!ret) {
189 av_log(h, AV_LOG_ERROR,
190 "The certificate's owner does not match hostname %s\n", c->host);
191 ret = AVERROR(EIO);
192 goto fail;
193 }
194 }
195
196 return 0;
197 fail:
198 tls_close(h);
199 return ret;
200 }
201
202 static int tls_read(URLContext *h, uint8_t *buf, int size)
203 {
204 TLSContext *c = h->priv_data;
205 int ret = gnutls_record_recv(c->session, buf, size);
206 if (ret > 0)
207 return ret;
208 if (ret == 0)
209 return AVERROR_EOF;
210 return print_tls_error(h, ret);
211 }
212
213 static int tls_write(URLContext *h, const uint8_t *buf, int size)
214 {
215 TLSContext *c = h->priv_data;
216 int ret = gnutls_record_send(c->session, buf, size);
217 if (ret > 0)
218 return ret;
219 if (ret == 0)
220 return AVERROR_EOF;
221 return print_tls_error(h, ret);
222 }
223
224 static const AVOption options[] = {
225 TLS_COMMON_OPTIONS(TLSContext, tls_shared),
226 { NULL }
227 };
228
229 static const AVClass tls_class = {
230 .class_name = "tls",
231 .item_name = av_default_item_name,
232 .option = options,
233 .version = LIBAVUTIL_VERSION_INT,
234 };
235
236 const URLProtocol ff_tls_protocol = {
237 .name = "tls",
238 .url_open2 = tls_open,
239 .url_read = tls_read,
240 .url_write = tls_write,
241 .url_close = tls_close,
242 .priv_data_size = sizeof(TLSContext),
243 .flags = URL_PROTOCOL_FLAG_NETWORK,
244 .priv_data_class = &tls_class,
245 };