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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 "avformat.h"
23 #include "internal.h"
24 #include "network.h"
25 #include "os_support.h"
26 #include "url.h"
27 #include "tls.h"
28 #include "libavcodec/internal.h"
29 #include "libavutil/avstring.h"
30 #include "libavutil/avutil.h"
31 #include "libavutil/opt.h"
32 #include "libavutil/parseutils.h"
33 #include "libavutil/thread.h"
34 
35 #include <openssl/bio.h>
36 #include <openssl/ssl.h>
37 #include <openssl/err.h>
38 
39 static int openssl_init;
40 
41 typedef struct TLSContext {
42     const AVClass *class;
43     TLSShared tls_shared;
44     SSL_CTX *ctx;
45     SSL *ssl;
46 #if OPENSSL_VERSION_NUMBER >= 0x1010000fL
47     BIO_METHOD* url_bio_method;
48 #endif
49 } TLSContext;
50 
51 #if HAVE_THREADS && OPENSSL_VERSION_NUMBER < 0x10100000L
52 #include <openssl/crypto.h>
53 pthread_mutex_t *openssl_mutexes;
openssl_lock(int mode,int type,const char * file,int line)54 static void openssl_lock(int mode, int type, const char *file, int line)
55 {
56     if (mode & CRYPTO_LOCK)
57         pthread_mutex_lock(&openssl_mutexes[type]);
58     else
59         pthread_mutex_unlock(&openssl_mutexes[type]);
60 }
61 #if !defined(WIN32) && OPENSSL_VERSION_NUMBER < 0x10000000
openssl_thread_id(void)62 static unsigned long openssl_thread_id(void)
63 {
64     return (intptr_t) pthread_self();
65 }
66 #endif
67 #endif
68 
ff_openssl_init(void)69 int ff_openssl_init(void)
70 {
71     ff_lock_avformat();
72     if (!openssl_init) {
73         /* OpenSSL 1.0.2 or below, then you would use SSL_library_init. If you are
74          * using OpenSSL 1.1.0 or above, then the library will initialize
75          * itself automatically.
76          * https://wiki.openssl.org/index.php/Library_Initialization
77          */
78 #if OPENSSL_VERSION_NUMBER < 0x10100000L
79         SSL_library_init();
80         SSL_load_error_strings();
81 #endif
82 #if HAVE_THREADS && OPENSSL_VERSION_NUMBER < 0x10100000L
83         if (!CRYPTO_get_locking_callback()) {
84             int i;
85             openssl_mutexes = av_malloc_array(sizeof(pthread_mutex_t), CRYPTO_num_locks());
86             if (!openssl_mutexes) {
87                 ff_unlock_avformat();
88                 return AVERROR(ENOMEM);
89             }
90 
91             for (i = 0; i < CRYPTO_num_locks(); i++)
92                 pthread_mutex_init(&openssl_mutexes[i], NULL);
93             CRYPTO_set_locking_callback(openssl_lock);
94 #if !defined(WIN32) && OPENSSL_VERSION_NUMBER < 0x10000000
95             CRYPTO_set_id_callback(openssl_thread_id);
96 #endif
97         }
98 #endif
99     }
100     openssl_init++;
101     ff_unlock_avformat();
102 
103     return 0;
104 }
105 
ff_openssl_deinit(void)106 void ff_openssl_deinit(void)
107 {
108     ff_lock_avformat();
109     openssl_init--;
110     if (!openssl_init) {
111 #if HAVE_THREADS && OPENSSL_VERSION_NUMBER < 0x10100000L
112         if (CRYPTO_get_locking_callback() == openssl_lock) {
113             int i;
114             CRYPTO_set_locking_callback(NULL);
115             for (i = 0; i < CRYPTO_num_locks(); i++)
116                 pthread_mutex_destroy(&openssl_mutexes[i]);
117             av_free(openssl_mutexes);
118         }
119 #endif
120     }
121     ff_unlock_avformat();
122 }
123 
print_tls_error(URLContext * h,int ret)124 static int print_tls_error(URLContext *h, int ret)
125 {
126     TLSContext *c = h->priv_data;
127     if (h->flags & AVIO_FLAG_NONBLOCK) {
128         int err = SSL_get_error(c->ssl, ret);
129         if (err == SSL_ERROR_WANT_READ || err == SSL_ERROR_WANT_WRITE)
130             return AVERROR(EAGAIN);
131     }
132     av_log(h, AV_LOG_ERROR, "%s\n", ERR_error_string(ERR_get_error(), NULL));
133     return AVERROR(EIO);
134 }
135 
tls_close(URLContext * h)136 static int tls_close(URLContext *h)
137 {
138     TLSContext *c = h->priv_data;
139     if (c->ssl) {
140         SSL_shutdown(c->ssl);
141         SSL_free(c->ssl);
142     }
143     if (c->ctx)
144         SSL_CTX_free(c->ctx);
145     ffurl_closep(&c->tls_shared.tcp);
146 #if OPENSSL_VERSION_NUMBER >= 0x1010000fL
147     if (c->url_bio_method)
148         BIO_meth_free(c->url_bio_method);
149 #endif
150     ff_openssl_deinit();
151     return 0;
152 }
153 
url_bio_create(BIO * b)154 static int url_bio_create(BIO *b)
155 {
156 #if OPENSSL_VERSION_NUMBER >= 0x1010000fL
157     BIO_set_init(b, 1);
158     BIO_set_data(b, NULL);
159     BIO_set_flags(b, 0);
160 #else
161     b->init = 1;
162     b->ptr = NULL;
163     b->flags = 0;
164 #endif
165     return 1;
166 }
167 
url_bio_destroy(BIO * b)168 static int url_bio_destroy(BIO *b)
169 {
170     return 1;
171 }
172 
173 #if OPENSSL_VERSION_NUMBER >= 0x1010000fL
174 #define GET_BIO_DATA(x) BIO_get_data(x)
175 #else
176 #define GET_BIO_DATA(x) (x)->ptr
177 #endif
178 
url_bio_bread(BIO * b,char * buf,int len)179 static int url_bio_bread(BIO *b, char *buf, int len)
180 {
181     URLContext *h = GET_BIO_DATA(b);
182     int ret = ffurl_read(h, buf, len);
183     if (ret >= 0)
184         return ret;
185     BIO_clear_retry_flags(b);
186     if (ret == AVERROR(EAGAIN))
187         BIO_set_retry_read(b);
188     if (ret == AVERROR_EXIT)
189         return 0;
190     return -1;
191 }
192 
url_bio_bwrite(BIO * b,const char * buf,int len)193 static int url_bio_bwrite(BIO *b, const char *buf, int len)
194 {
195     URLContext *h = GET_BIO_DATA(b);
196     int ret = ffurl_write(h, buf, len);
197     if (ret >= 0)
198         return ret;
199     BIO_clear_retry_flags(b);
200     if (ret == AVERROR(EAGAIN))
201         BIO_set_retry_write(b);
202     if (ret == AVERROR_EXIT)
203         return 0;
204     return -1;
205 }
206 
url_bio_ctrl(BIO * b,int cmd,long num,void * ptr)207 static long url_bio_ctrl(BIO *b, int cmd, long num, void *ptr)
208 {
209     if (cmd == BIO_CTRL_FLUSH) {
210         BIO_clear_retry_flags(b);
211         return 1;
212     }
213     return 0;
214 }
215 
url_bio_bputs(BIO * b,const char * str)216 static int url_bio_bputs(BIO *b, const char *str)
217 {
218     return url_bio_bwrite(b, str, strlen(str));
219 }
220 
221 #if OPENSSL_VERSION_NUMBER < 0x1010000fL
222 static BIO_METHOD url_bio_method = {
223     .type = BIO_TYPE_SOURCE_SINK,
224     .name = "urlprotocol bio",
225     .bwrite = url_bio_bwrite,
226     .bread = url_bio_bread,
227     .bputs = url_bio_bputs,
228     .bgets = NULL,
229     .ctrl = url_bio_ctrl,
230     .create = url_bio_create,
231     .destroy = url_bio_destroy,
232 };
233 #endif
234 
tls_open(URLContext * h,const char * uri,int flags,AVDictionary ** options)235 static int tls_open(URLContext *h, const char *uri, int flags, AVDictionary **options)
236 {
237     TLSContext *p = h->priv_data;
238     TLSShared *c = &p->tls_shared;
239     BIO *bio;
240     int ret;
241 
242     if ((ret = ff_openssl_init()) < 0)
243         return ret;
244 
245     if ((ret = ff_tls_open_underlying(c, h, uri, options)) < 0)
246         goto fail;
247 
248     // We want to support all versions of TLS >= 1.0, but not the deprecated
249     // and insecure SSLv2 and SSLv3.  Despite the name, SSLv23_*_method()
250     // enables support for all versions of SSL and TLS, and we then disable
251     // support for the old protocols immediately after creating the context.
252     p->ctx = SSL_CTX_new(c->listen ? SSLv23_server_method() : SSLv23_client_method());
253     if (!p->ctx) {
254         av_log(h, AV_LOG_ERROR, "%s\n", ERR_error_string(ERR_get_error(), NULL));
255         ret = AVERROR(EIO);
256         goto fail;
257     }
258     SSL_CTX_set_options(p->ctx, SSL_OP_NO_SSLv2 | SSL_OP_NO_SSLv3);
259     if (c->ca_file) {
260         if (!SSL_CTX_load_verify_locations(p->ctx, c->ca_file, NULL))
261             av_log(h, AV_LOG_ERROR, "SSL_CTX_load_verify_locations %s\n", ERR_error_string(ERR_get_error(), NULL));
262     }
263     if (c->cert_file && !SSL_CTX_use_certificate_chain_file(p->ctx, c->cert_file)) {
264         av_log(h, AV_LOG_ERROR, "Unable to load cert file %s: %s\n",
265                c->cert_file, ERR_error_string(ERR_get_error(), NULL));
266         ret = AVERROR(EIO);
267         goto fail;
268     }
269     if (c->key_file && !SSL_CTX_use_PrivateKey_file(p->ctx, c->key_file, SSL_FILETYPE_PEM)) {
270         av_log(h, AV_LOG_ERROR, "Unable to load key file %s: %s\n",
271                c->key_file, ERR_error_string(ERR_get_error(), NULL));
272         ret = AVERROR(EIO);
273         goto fail;
274     }
275     // Note, this doesn't check that the peer certificate actually matches
276     // the requested hostname.
277     if (c->verify)
278         SSL_CTX_set_verify(p->ctx, SSL_VERIFY_PEER|SSL_VERIFY_FAIL_IF_NO_PEER_CERT, NULL);
279     p->ssl = SSL_new(p->ctx);
280     if (!p->ssl) {
281         av_log(h, AV_LOG_ERROR, "%s\n", ERR_error_string(ERR_get_error(), NULL));
282         ret = AVERROR(EIO);
283         goto fail;
284     }
285 #if OPENSSL_VERSION_NUMBER >= 0x1010000fL
286     p->url_bio_method = BIO_meth_new(BIO_TYPE_SOURCE_SINK, "urlprotocol bio");
287     BIO_meth_set_write(p->url_bio_method, url_bio_bwrite);
288     BIO_meth_set_read(p->url_bio_method, url_bio_bread);
289     BIO_meth_set_puts(p->url_bio_method, url_bio_bputs);
290     BIO_meth_set_ctrl(p->url_bio_method, url_bio_ctrl);
291     BIO_meth_set_create(p->url_bio_method, url_bio_create);
292     BIO_meth_set_destroy(p->url_bio_method, url_bio_destroy);
293     bio = BIO_new(p->url_bio_method);
294     BIO_set_data(bio, c->tcp);
295 #else
296     bio = BIO_new(&url_bio_method);
297     bio->ptr = c->tcp;
298 #endif
299     SSL_set_bio(p->ssl, bio, bio);
300     if (!c->listen && !c->numerichost)
301         SSL_set_tlsext_host_name(p->ssl, c->host);
302     ret = c->listen ? SSL_accept(p->ssl) : SSL_connect(p->ssl);
303     if (ret == 0) {
304         av_log(h, AV_LOG_ERROR, "Unable to negotiate TLS/SSL session\n");
305         ret = AVERROR(EIO);
306         goto fail;
307     } else if (ret < 0) {
308         ret = print_tls_error(h, ret);
309         goto fail;
310     }
311 
312     return 0;
313 fail:
314     tls_close(h);
315     return ret;
316 }
317 
tls_read(URLContext * h,uint8_t * buf,int size)318 static int tls_read(URLContext *h, uint8_t *buf, int size)
319 {
320     TLSContext *c = h->priv_data;
321     int ret;
322     // Set or clear the AVIO_FLAG_NONBLOCK on c->tls_shared.tcp
323     c->tls_shared.tcp->flags &= ~AVIO_FLAG_NONBLOCK;
324     c->tls_shared.tcp->flags |= h->flags & AVIO_FLAG_NONBLOCK;
325     ret = SSL_read(c->ssl, buf, size);
326     if (ret > 0)
327         return ret;
328     if (ret == 0)
329         return AVERROR_EOF;
330     return print_tls_error(h, ret);
331 }
332 
tls_write(URLContext * h,const uint8_t * buf,int size)333 static int tls_write(URLContext *h, const uint8_t *buf, int size)
334 {
335     TLSContext *c = h->priv_data;
336     int ret;
337     // Set or clear the AVIO_FLAG_NONBLOCK on c->tls_shared.tcp
338     c->tls_shared.tcp->flags &= ~AVIO_FLAG_NONBLOCK;
339     c->tls_shared.tcp->flags |= h->flags & AVIO_FLAG_NONBLOCK;
340     ret = SSL_write(c->ssl, buf, size);
341     if (ret > 0)
342         return ret;
343     if (ret == 0)
344         return AVERROR_EOF;
345     return print_tls_error(h, ret);
346 }
347 
tls_get_file_handle(URLContext * h)348 static int tls_get_file_handle(URLContext *h)
349 {
350     TLSContext *c = h->priv_data;
351     return ffurl_get_file_handle(c->tls_shared.tcp);
352 }
353 
tls_get_short_seek(URLContext * h)354 static int tls_get_short_seek(URLContext *h)
355 {
356     TLSContext *s = h->priv_data;
357     return ffurl_get_short_seek(s->tls_shared.tcp);
358 }
359 
360 static const AVOption options[] = {
361     TLS_COMMON_OPTIONS(TLSContext, tls_shared),
362     { NULL }
363 };
364 
365 static const AVClass tls_class = {
366     .class_name = "tls",
367     .item_name  = av_default_item_name,
368     .option     = options,
369     .version    = LIBAVUTIL_VERSION_INT,
370 };
371 
372 const URLProtocol ff_tls_protocol = {
373     .name           = "tls",
374     .url_open2      = tls_open,
375     .url_read       = tls_read,
376     .url_write      = tls_write,
377     .url_close      = tls_close,
378     .url_get_file_handle = tls_get_file_handle,
379     .url_get_short_seek  = tls_get_short_seek,
380     .priv_data_size = sizeof(TLSContext),
381     .flags          = URL_PROTOCOL_FLAG_NETWORK,
382     .priv_data_class = &tls_class,
383 };
384