libavformat/tls_openssl.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 "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     int io_err;
  50 } TLSContext;
  51
  52 #if HAVE_THREADS && OPENSSL_VERSION_NUMBER < 0x10100000L
  53 #include <openssl/crypto.h>
  54 pthread_mutex_t *openssl_mutexes;
  55 static void openssl_lock(int mode, int type, const char *file, int line)
  56 {
  57     if (mode & CRYPTO_LOCK)
  58         pthread_mutex_lock(&openssl_mutexes[type]);
  59     else
  60         pthread_mutex_unlock(&openssl_mutexes[type]);
  61 }
  62 #if !defined(WIN32) && OPENSSL_VERSION_NUMBER < 0x10000000
  63 static unsigned long openssl_thread_id(void)
  64 {
  65     return (intptr_t) pthread_self();
  66 }
  67 #endif
  68 #endif
  69
  70 int ff_openssl_init(void)
  71 {
  72     ff_lock_avformat();
  73     if (!openssl_init) {
  74         /* OpenSSL 1.0.2 or below, then you would use SSL_library_init. If you are
  75          * using OpenSSL 1.1.0 or above, then the library will initialize
  76          * itself automatically.
  77          * https://wiki.openssl.org/index.php/Library_Initialization
  78          */
  79 #if OPENSSL_VERSION_NUMBER < 0x10100000L
  80         SSL_library_init();
  81         SSL_load_error_strings();
  82 #endif
  83 #if HAVE_THREADS && OPENSSL_VERSION_NUMBER < 0x10100000L
  84         if (!CRYPTO_get_locking_callback()) {
  85             int i;
  86             openssl_mutexes = av_malloc_array(sizeof(pthread_mutex_t), CRYPTO_num_locks());
  87             if (!openssl_mutexes) {
  88                 ff_unlock_avformat();
  89                 return AVERROR(ENOMEM);
  90             }
  91
  92             for (i = 0; i < CRYPTO_num_locks(); i++)
  93                 pthread_mutex_init(&openssl_mutexes[i], NULL);
  94             CRYPTO_set_locking_callback(openssl_lock);
  95 #if !defined(WIN32) && OPENSSL_VERSION_NUMBER < 0x10000000
  96             CRYPTO_set_id_callback(openssl_thread_id);
  97 #endif
  98         }
  99 #endif
 100     }
 101     openssl_init++;
 102     ff_unlock_avformat();
 103
 104     return 0;
 105 }
 106
 107 void ff_openssl_deinit(void)
 108 {
 109     ff_lock_avformat();
 110     openssl_init--;
 111     if (!openssl_init) {
 112 #if HAVE_THREADS && OPENSSL_VERSION_NUMBER < 0x10100000L
 113         if (CRYPTO_get_locking_callback() == openssl_lock) {
 114             int i;
 115             CRYPTO_set_locking_callback(NULL);
 116             for (i = 0; i < CRYPTO_num_locks(); i++)
 117                 pthread_mutex_destroy(&openssl_mutexes[i]);
 118             av_free(openssl_mutexes);
 119         }
 120 #endif
 121     }
 122     ff_unlock_avformat();
 123 }
 124
 125 static int print_tls_error(URLContext *h, int ret)
 126 {
 127     TLSContext *c = h->priv_data;
 128     int printed = 0, e, averr = AVERROR(EIO);
 129     if (h->flags & AVIO_FLAG_NONBLOCK) {
 130         int err = SSL_get_error(c->ssl, ret);
 131         if (err == SSL_ERROR_WANT_READ || err == SSL_ERROR_WANT_WRITE)
 132             return AVERROR(EAGAIN);
 133     }
 134     while ((e = ERR_get_error()) != 0) {
 135         av_log(h, AV_LOG_ERROR, "%s\n", ERR_error_string(e, NULL));
 136         printed = 1;
 137     }
 138     if (c->io_err) {
 139         av_log(h, AV_LOG_ERROR, "IO error: %s\n", av_err2str(c->io_err));
 140         printed = 1;
 141         averr = c->io_err;
 142         c->io_err = 0;
 143     }
 144     if (!printed)
 145         av_log(h, AV_LOG_ERROR, "Unknown error\n");
 146     return averr;
 147 }
 148
 149 static int tls_close(URLContext *h)
 150 {
 151     TLSContext *c = h->priv_data;
 152     if (c->ssl) {
 153         SSL_shutdown(c->ssl);
 154         SSL_free(c->ssl);
 155     }
 156     if (c->ctx)
 157         SSL_CTX_free(c->ctx);
 158     ffurl_closep(&c->tls_shared.tcp);
 159 #if OPENSSL_VERSION_NUMBER >= 0x1010000fL
 160     if (c->url_bio_method)
 161         BIO_meth_free(c->url_bio_method);
 162 #endif
 163     ff_openssl_deinit();
 164     return 0;
 165 }
 166
 167 static int url_bio_create(BIO *b)
 168 {
 169 #if OPENSSL_VERSION_NUMBER >= 0x1010000fL
 170     BIO_set_init(b, 1);
 171     BIO_set_data(b, NULL);
 172     BIO_set_flags(b, 0);
 173 #else
 174     b->init = 1;
 175     b->ptr = NULL;
 176     b->flags = 0;
 177 #endif
 178     return 1;
 179 }
 180
 181 static int url_bio_destroy(BIO *b)
 182 {
 183     return 1;
 184 }
 185
 186 #if OPENSSL_VERSION_NUMBER >= 0x1010000fL
 187 #define GET_BIO_DATA(x) BIO_get_data(x)
 188 #else
 189 #define GET_BIO_DATA(x) (x)->ptr
 190 #endif
 191
 192 static int url_bio_bread(BIO *b, char *buf, int len)
 193 {
 194     TLSContext *c = GET_BIO_DATA(b);
 195     int ret = ffurl_read(c->tls_shared.tcp, buf, len);
 196     if (ret >= 0)
 197         return ret;
 198     BIO_clear_retry_flags(b);
 199     if (ret == AVERROR_EXIT)
 200         return 0;
 201     if (ret == AVERROR(EAGAIN))
 202         BIO_set_retry_read(b);
 203     else
 204         c->io_err = ret;
 205     return -1;
 206 }
 207
 208 static int url_bio_bwrite(BIO *b, const char *buf, int len)
 209 {
 210     TLSContext *c = GET_BIO_DATA(b);
 211     int ret = ffurl_write(c->tls_shared.tcp, buf, len);
 212     if (ret >= 0)
 213         return ret;
 214     BIO_clear_retry_flags(b);
 215     if (ret == AVERROR_EXIT)
 216         return 0;
 217     if (ret == AVERROR(EAGAIN))
 218         BIO_set_retry_write(b);
 219     else
 220         c->io_err = ret;
 221     return -1;
 222 }
 223
 224 static long url_bio_ctrl(BIO *b, int cmd, long num, void *ptr)
 225 {
 226     if (cmd == BIO_CTRL_FLUSH) {
 227         BIO_clear_retry_flags(b);
 228         return 1;
 229     }
 230     return 0;
 231 }
 232
 233 static int url_bio_bputs(BIO *b, const char *str)
 234 {
 235     return url_bio_bwrite(b, str, strlen(str));
 236 }
 237
 238 #if OPENSSL_VERSION_NUMBER < 0x1010000fL
 239 static BIO_METHOD url_bio_method = {
 240     .type = BIO_TYPE_SOURCE_SINK,
 241     .name = "urlprotocol bio",
 242     .bwrite = url_bio_bwrite,
 243     .bread = url_bio_bread,
 244     .bputs = url_bio_bputs,
 245     .bgets = NULL,
 246     .ctrl = url_bio_ctrl,
 247     .create = url_bio_create,
 248     .destroy = url_bio_destroy,
 249 };
 250 #endif
 251
 252 static int tls_open(URLContext *h, const char *uri, int flags, AVDictionary **options)
 253 {
 254     TLSContext *p = h->priv_data;
 255     TLSShared *c = &p->tls_shared;
 256     BIO *bio;
 257     int ret;
 258
 259     if ((ret = ff_openssl_init()) < 0)
 260         return ret;
 261
 262     if ((ret = ff_tls_open_underlying(c, h, uri, options)) < 0)
 263         goto fail;
 264
 265     // We want to support all versions of TLS >= 1.0, but not the deprecated
 266     // and insecure SSLv2 and SSLv3.  Despite the name, SSLv23_*_method()
 267     // enables support for all versions of SSL and TLS, and we then disable
 268     // support for the old protocols immediately after creating the context.
 269     p->ctx = SSL_CTX_new(c->listen ? SSLv23_server_method() : SSLv23_client_method());
 270     if (!p->ctx) {
 271         av_log(h, AV_LOG_ERROR, "%s\n", ERR_error_string(ERR_get_error(), NULL));
 272         ret = AVERROR(EIO);
 273         goto fail;
 274     }
 275     SSL_CTX_set_options(p->ctx, SSL_OP_NO_SSLv2 | SSL_OP_NO_SSLv3);
 276     if (c->ca_file) {
 277         if (!SSL_CTX_load_verify_locations(p->ctx, c->ca_file, NULL))
 278             av_log(h, AV_LOG_ERROR, "SSL_CTX_load_verify_locations %s\n", ERR_error_string(ERR_get_error(), NULL));
 279     }
 280     if (c->cert_file && !SSL_CTX_use_certificate_chain_file(p->ctx, c->cert_file)) {
 281         av_log(h, AV_LOG_ERROR, "Unable to load cert file %s: %s\n",
 282                c->cert_file, ERR_error_string(ERR_get_error(), NULL));
 283         ret = AVERROR(EIO);
 284         goto fail;
 285     }
 286     if (c->key_file && !SSL_CTX_use_PrivateKey_file(p->ctx, c->key_file, SSL_FILETYPE_PEM)) {
 287         av_log(h, AV_LOG_ERROR, "Unable to load key file %s: %s\n",
 288                c->key_file, ERR_error_string(ERR_get_error(), NULL));
 289         ret = AVERROR(EIO);
 290         goto fail;
 291     }
 292     // Note, this doesn't check that the peer certificate actually matches
 293     // the requested hostname.
 294     if (c->verify)
 295         SSL_CTX_set_verify(p->ctx, SSL_VERIFY_PEER|SSL_VERIFY_FAIL_IF_NO_PEER_CERT, NULL);
 296     p->ssl = SSL_new(p->ctx);
 297     if (!p->ssl) {
 298         av_log(h, AV_LOG_ERROR, "%s\n", ERR_error_string(ERR_get_error(), NULL));
 299         ret = AVERROR(EIO);
 300         goto fail;
 301     }
 302 #if OPENSSL_VERSION_NUMBER >= 0x1010000fL
 303     p->url_bio_method = BIO_meth_new(BIO_TYPE_SOURCE_SINK, "urlprotocol bio");
 304     BIO_meth_set_write(p->url_bio_method, url_bio_bwrite);
 305     BIO_meth_set_read(p->url_bio_method, url_bio_bread);
 306     BIO_meth_set_puts(p->url_bio_method, url_bio_bputs);
 307     BIO_meth_set_ctrl(p->url_bio_method, url_bio_ctrl);
 308     BIO_meth_set_create(p->url_bio_method, url_bio_create);
 309     BIO_meth_set_destroy(p->url_bio_method, url_bio_destroy);
 310     bio = BIO_new(p->url_bio_method);
 311     BIO_set_data(bio, p);
 312 #else
 313     bio = BIO_new(&url_bio_method);
 314     bio->ptr = p;
 315 #endif
 316     SSL_set_bio(p->ssl, bio, bio);
 317     if (!c->listen && !c->numerichost)
 318         SSL_set_tlsext_host_name(p->ssl, c->host);
 319     ret = c->listen ? SSL_accept(p->ssl) : SSL_connect(p->ssl);
 320     if (ret == 0) {
 321         av_log(h, AV_LOG_ERROR, "Unable to negotiate TLS/SSL session\n");
 322         ret = AVERROR(EIO);
 323         goto fail;
 324     } else if (ret < 0) {
 325         ret = print_tls_error(h, ret);
 326         goto fail;
 327     }
 328
 329     return 0;
 330 fail:
 331     tls_close(h);
 332     return ret;
 333 }
 334
 335 static int tls_read(URLContext *h, uint8_t *buf, int size)
 336 {
 337     TLSContext *c = h->priv_data;
 338     int ret;
 339     // Set or clear the AVIO_FLAG_NONBLOCK on c->tls_shared.tcp
 340     c->tls_shared.tcp->flags &= ~AVIO_FLAG_NONBLOCK;
 341     c->tls_shared.tcp->flags |= h->flags & AVIO_FLAG_NONBLOCK;
 342     ret = SSL_read(c->ssl, buf, size);
 343     if (ret > 0)
 344         return ret;
 345     if (ret == 0)
 346         return AVERROR_EOF;
 347     return print_tls_error(h, ret);
 348 }
 349
 350 static int tls_write(URLContext *h, const uint8_t *buf, int size)
 351 {
 352     TLSContext *c = h->priv_data;
 353     int ret;
 354     // Set or clear the AVIO_FLAG_NONBLOCK on c->tls_shared.tcp
 355     c->tls_shared.tcp->flags &= ~AVIO_FLAG_NONBLOCK;
 356     c->tls_shared.tcp->flags |= h->flags & AVIO_FLAG_NONBLOCK;
 357     ret = SSL_write(c->ssl, buf, size);
 358     if (ret > 0)
 359         return ret;
 360     if (ret == 0)
 361         return AVERROR_EOF;
 362     return print_tls_error(h, ret);
 363 }
 364
 365 static int tls_get_file_handle(URLContext *h)
 366 {
 367     TLSContext *c = h->priv_data;
 368     return ffurl_get_file_handle(c->tls_shared.tcp);
 369 }
 370
 371 static int tls_get_short_seek(URLContext *h)
 372 {
 373     TLSContext *s = h->priv_data;
 374     return ffurl_get_short_seek(s->tls_shared.tcp);
 375 }
 376
 377 static const AVOption options[] = {
 378     TLS_COMMON_OPTIONS(TLSContext, tls_shared),
 379     { NULL }
 380 };
 381
 382 static const AVClass tls_class = {
 383     .class_name = "tls",
 384     .item_name  = av_default_item_name,
 385     .option     = options,
 386     .version    = LIBAVUTIL_VERSION_INT,
 387 };
 388
 389 const URLProtocol ff_tls_protocol = {
 390     .name           = "tls",
 391     .url_open2      = tls_open,
 392     .url_read       = tls_read,
 393     .url_write      = tls_write,
 394     .url_close      = tls_close,
 395     .url_get_file_handle = tls_get_file_handle,
 396     .url_get_short_seek  = tls_get_short_seek,
 397     .priv_data_size = sizeof(TLSContext),
 398     .flags          = URL_PROTOCOL_FLAG_NETWORK,
 399     .priv_data_class = &tls_class,
 400 };