| /* |
| * TLS/SSL Protocol |
| * Copyright (c) 2018 Thomas Volkert |
| * |
| * 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 |
| */ |
| |
| #include <mbedtls/certs.h> |
| #include <mbedtls/config.h> |
| #include <mbedtls/ctr_drbg.h> |
| #include <mbedtls/entropy.h> |
| #include <mbedtls/net_sockets.h> |
| #include <mbedtls/platform.h> |
| #include <mbedtls/ssl.h> |
| #include <mbedtls/x509_crt.h> |
| |
| #include "avformat.h" |
| #include "internal.h" |
| #include "url.h" |
| #include "tls.h" |
| #include "libavutil/parseutils.h" |
| |
| typedef struct TLSContext { |
| const AVClass *class; |
| TLSShared tls_shared; |
| mbedtls_ssl_context ssl_context; |
| mbedtls_ssl_config ssl_config; |
| mbedtls_entropy_context entropy_context; |
| mbedtls_ctr_drbg_context ctr_drbg_context; |
| mbedtls_x509_crt ca_cert; |
| mbedtls_x509_crt own_cert; |
| mbedtls_pk_context priv_key; |
| char *priv_key_pw; |
| } TLSContext; |
| |
| #define OFFSET(x) offsetof(TLSContext, x) |
| |
| static int tls_close(URLContext *h) |
| { |
| TLSContext *tls_ctx = h->priv_data; |
| |
| mbedtls_ssl_close_notify(&tls_ctx->ssl_context); |
| mbedtls_pk_free(&tls_ctx->priv_key); |
| mbedtls_x509_crt_free(&tls_ctx->ca_cert); |
| mbedtls_x509_crt_free(&tls_ctx->own_cert); |
| mbedtls_ssl_free(&tls_ctx->ssl_context); |
| mbedtls_ssl_config_free(&tls_ctx->ssl_config); |
| mbedtls_ctr_drbg_free(&tls_ctx->ctr_drbg_context); |
| mbedtls_entropy_free(&tls_ctx->entropy_context); |
| |
| ffurl_closep(&tls_ctx->tls_shared.tcp); |
| return 0; |
| } |
| |
| static int handle_transport_error(URLContext *h, const char* func_name, int react_on_eagain, int ret) |
| { |
| switch (ret) { |
| case AVERROR(EAGAIN): |
| return react_on_eagain; |
| case AVERROR_EXIT: |
| return 0; |
| case AVERROR(EPIPE): |
| case AVERROR(ECONNRESET): |
| return MBEDTLS_ERR_NET_CONN_RESET; |
| default: |
| av_log(h, AV_LOG_ERROR, "%s returned 0x%x\n", func_name, ret); |
| errno = EIO; |
| return MBEDTLS_ERR_NET_SEND_FAILED; |
| } |
| } |
| |
| static int mbedtls_send(void *ctx, const unsigned char *buf, size_t len) |
| { |
| URLContext *h = (URLContext*) ctx; |
| int ret = ffurl_write(h, buf, len); |
| if (ret >= 0) |
| return ret; |
| |
| if (h->max_packet_size && len > h->max_packet_size) |
| return MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL; |
| |
| return handle_transport_error(h, "ffurl_write", MBEDTLS_ERR_SSL_WANT_WRITE, ret); |
| } |
| |
| static int mbedtls_recv(void *ctx, unsigned char *buf, size_t len) |
| { |
| URLContext *h = (URLContext*) ctx; |
| int ret = ffurl_read(h, buf, len); |
| if (ret >= 0) |
| return ret; |
| |
| if (h->max_packet_size && len > h->max_packet_size) |
| return MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL; |
| |
| return handle_transport_error(h, "ffurl_read", MBEDTLS_ERR_SSL_WANT_READ, ret); |
| } |
| |
| static void handle_pk_parse_error(URLContext *h, int ret) |
| { |
| switch (ret) { |
| case MBEDTLS_ERR_PK_FILE_IO_ERROR: |
| av_log(h, AV_LOG_ERROR, "Read of key file failed. Is it actually there, are the access permissions correct?\n"); |
| break; |
| case MBEDTLS_ERR_PK_PASSWORD_REQUIRED: |
| av_log(h, AV_LOG_ERROR, "A password for the private key is missing.\n"); |
| break; |
| case MBEDTLS_ERR_PK_PASSWORD_MISMATCH: |
| av_log(h, AV_LOG_ERROR, "The given password for the private key is wrong.\n"); |
| break; |
| default: |
| av_log(h, AV_LOG_ERROR, "mbedtls_pk_parse_key returned -0x%x\n", -ret); |
| break; |
| } |
| } |
| |
| static void handle_handshake_error(URLContext *h, int ret) |
| { |
| switch (ret) { |
| case MBEDTLS_ERR_SSL_NO_USABLE_CIPHERSUITE: |
| av_log(h, AV_LOG_ERROR, "None of the common ciphersuites is usable. Was the local certificate correctly set?\n"); |
| break; |
| case MBEDTLS_ERR_SSL_FATAL_ALERT_MESSAGE: |
| av_log(h, AV_LOG_ERROR, "A fatal alert message was received from the peer, has the peer a correct certificate?\n"); |
| break; |
| case MBEDTLS_ERR_SSL_CA_CHAIN_REQUIRED: |
| av_log(h, AV_LOG_ERROR, "No CA chain is set, but required to operate. Was the CA correctly set?\n"); |
| break; |
| case MBEDTLS_ERR_NET_CONN_RESET: |
| av_log(h, AV_LOG_ERROR, "TLS handshake was aborted by peer.\n"); |
| break; |
| default: |
| av_log(h, AV_LOG_ERROR, "mbedtls_ssl_handshake returned -0x%x\n", -ret); |
| break; |
| } |
| } |
| |
| static void parse_options(TLSContext *tls_ctxc, const char *uri) |
| { |
| char buf[1024]; |
| const char *p = strchr(uri, '?'); |
| if (!p) |
| return; |
| |
| if (!tls_ctxc->priv_key_pw && av_find_info_tag(buf, sizeof(buf), "key_password", p)) |
| tls_ctxc->priv_key_pw = av_strdup(buf); |
| } |
| |
| static int tls_open(URLContext *h, const char *uri, int flags, AVDictionary **options) |
| { |
| TLSContext *tls_ctx = h->priv_data; |
| TLSShared *shr = &tls_ctx->tls_shared; |
| uint32_t verify_res_flags; |
| int ret; |
| |
| // parse additional options |
| parse_options(tls_ctx, uri); |
| |
| if ((ret = ff_tls_open_underlying(shr, h, uri, options)) < 0) |
| goto fail; |
| |
| mbedtls_ssl_init(&tls_ctx->ssl_context); |
| mbedtls_ssl_config_init(&tls_ctx->ssl_config); |
| mbedtls_entropy_init(&tls_ctx->entropy_context); |
| mbedtls_ctr_drbg_init(&tls_ctx->ctr_drbg_context); |
| mbedtls_x509_crt_init(&tls_ctx->ca_cert); |
| mbedtls_pk_init(&tls_ctx->priv_key); |
| |
| // load trusted CA |
| if (shr->ca_file) { |
| if ((ret = mbedtls_x509_crt_parse_file(&tls_ctx->ca_cert, shr->ca_file)) != 0) { |
| av_log(h, AV_LOG_ERROR, "mbedtls_x509_crt_parse_file for CA cert returned %d\n", ret); |
| goto fail; |
| } |
| } |
| |
| // load own certificate |
| if (shr->cert_file) { |
| if ((ret = mbedtls_x509_crt_parse_file(&tls_ctx->own_cert, shr->cert_file)) != 0) { |
| av_log(h, AV_LOG_ERROR, "mbedtls_x509_crt_parse_file for own cert returned %d\n", ret); |
| goto fail; |
| } |
| } |
| |
| // load key file |
| if (shr->key_file) { |
| if ((ret = mbedtls_pk_parse_keyfile(&tls_ctx->priv_key, |
| shr->key_file, |
| tls_ctx->priv_key_pw)) != 0) { |
| handle_pk_parse_error(h, ret); |
| goto fail; |
| } |
| } |
| |
| // seed the random number generator |
| if ((ret = mbedtls_ctr_drbg_seed(&tls_ctx->ctr_drbg_context, |
| mbedtls_entropy_func, |
| &tls_ctx->entropy_context, |
| NULL, 0)) != 0) { |
| av_log(h, AV_LOG_ERROR, "mbedtls_ctr_drbg_seed returned %d\n", ret); |
| goto fail; |
| } |
| |
| if ((ret = mbedtls_ssl_config_defaults(&tls_ctx->ssl_config, |
| shr->listen ? MBEDTLS_SSL_IS_SERVER : MBEDTLS_SSL_IS_CLIENT, |
| MBEDTLS_SSL_TRANSPORT_STREAM, |
| MBEDTLS_SSL_PRESET_DEFAULT)) != 0) { |
| av_log(h, AV_LOG_ERROR, "mbedtls_ssl_config_defaults returned %d\n", ret); |
| goto fail; |
| } |
| |
| mbedtls_ssl_conf_authmode(&tls_ctx->ssl_config, |
| shr->ca_file ? MBEDTLS_SSL_VERIFY_REQUIRED : MBEDTLS_SSL_VERIFY_NONE); |
| mbedtls_ssl_conf_rng(&tls_ctx->ssl_config, mbedtls_ctr_drbg_random, &tls_ctx->ctr_drbg_context); |
| mbedtls_ssl_conf_ca_chain(&tls_ctx->ssl_config, &tls_ctx->ca_cert, NULL); |
| |
| // set own certificate and private key |
| if ((ret = mbedtls_ssl_conf_own_cert(&tls_ctx->ssl_config, &tls_ctx->own_cert, &tls_ctx->priv_key)) != 0) { |
| av_log(h, AV_LOG_ERROR, "mbedtls_ssl_conf_own_cert returned %d\n", ret); |
| goto fail; |
| } |
| |
| if ((ret = mbedtls_ssl_setup(&tls_ctx->ssl_context, &tls_ctx->ssl_config)) != 0) { |
| av_log(h, AV_LOG_ERROR, "mbedtls_ssl_setup returned %d\n", ret); |
| goto fail; |
| } |
| |
| if (!shr->listen && !shr->numerichost) { |
| if ((ret = mbedtls_ssl_set_hostname(&tls_ctx->ssl_context, shr->host)) != 0) { |
| av_log(h, AV_LOG_ERROR, "mbedtls_ssl_set_hostname returned %d\n", ret); |
| goto fail; |
| } |
| } |
| |
| // set I/O functions to use FFmpeg internal code for transport layer |
| mbedtls_ssl_set_bio(&tls_ctx->ssl_context, shr->tcp, mbedtls_send, mbedtls_recv, NULL); |
| |
| // ssl handshake |
| while ((ret = mbedtls_ssl_handshake(&tls_ctx->ssl_context)) != 0) { |
| if (ret != MBEDTLS_ERR_SSL_WANT_READ && ret != MBEDTLS_ERR_SSL_WANT_WRITE) { |
| handle_handshake_error(h, ret); |
| goto fail; |
| } |
| } |
| |
| if (shr->verify) { |
| // check the result of the certificate verification |
| if ((verify_res_flags = mbedtls_ssl_get_verify_result(&tls_ctx->ssl_context)) != 0) { |
| av_log(h, AV_LOG_ERROR, "mbedtls_ssl_get_verify_result reported problems "\ |
| "with the certificate verification, returned flags: %u\n", |
| verify_res_flags); |
| if (verify_res_flags & MBEDTLS_X509_BADCERT_NOT_TRUSTED) |
| av_log(h, AV_LOG_ERROR, "The certificate is not correctly signed by the trusted CA.\n"); |
| goto fail; |
| } |
| } |
| |
| return 0; |
| |
| fail: |
| tls_close(h); |
| return AVERROR(EIO); |
| } |
| |
| static int handle_tls_error(URLContext *h, const char* func_name, int ret) |
| { |
| switch (ret) { |
| case MBEDTLS_ERR_SSL_WANT_READ: |
| case MBEDTLS_ERR_SSL_WANT_WRITE: |
| return AVERROR(EAGAIN); |
| case MBEDTLS_ERR_NET_SEND_FAILED: |
| case MBEDTLS_ERR_NET_RECV_FAILED: |
| return AVERROR(EIO); |
| case MBEDTLS_ERR_NET_CONN_RESET: |
| case MBEDTLS_ERR_SSL_PEER_CLOSE_NOTIFY: |
| av_log(h, AV_LOG_WARNING, "%s reported connection reset by peer\n", func_name); |
| return AVERROR_EOF; |
| default: |
| av_log(h, AV_LOG_ERROR, "%s returned -0x%x\n", func_name, -ret); |
| return AVERROR(EIO); |
| } |
| } |
| |
| static int tls_read(URLContext *h, uint8_t *buf, int size) |
| { |
| TLSContext *tls_ctx = h->priv_data; |
| int ret; |
| |
| if ((ret = mbedtls_ssl_read(&tls_ctx->ssl_context, buf, size)) > 0) { |
| // return read length |
| return ret; |
| } |
| |
| return handle_tls_error(h, "mbedtls_ssl_read", ret); |
| } |
| |
| static int tls_write(URLContext *h, const uint8_t *buf, int size) |
| { |
| TLSContext *tls_ctx = h->priv_data; |
| int ret; |
| |
| if ((ret = mbedtls_ssl_write(&tls_ctx->ssl_context, buf, size)) > 0) { |
| // return written length |
| return ret; |
| } |
| |
| return handle_tls_error(h, "mbedtls_ssl_write", ret); |
| } |
| |
| static int tls_get_file_handle(URLContext *h) |
| { |
| TLSContext *c = h->priv_data; |
| return ffurl_get_file_handle(c->tls_shared.tcp); |
| } |
| |
| static int tls_get_short_seek(URLContext *h) |
| { |
| TLSContext *s = h->priv_data; |
| return ffurl_get_short_seek(s->tls_shared.tcp); |
| } |
| |
| static const AVOption options[] = { |
| TLS_COMMON_OPTIONS(TLSContext, tls_shared), \ |
| {"key_password", "Password for the private key file", OFFSET(priv_key_pw), AV_OPT_TYPE_STRING, .flags = TLS_OPTFL }, \ |
| { NULL } |
| }; |
| |
| static const AVClass tls_class = { |
| .class_name = "tls", |
| .item_name = av_default_item_name, |
| .option = options, |
| .version = LIBAVUTIL_VERSION_INT, |
| }; |
| |
| const URLProtocol ff_tls_protocol = { |
| .name = "tls", |
| .url_open2 = tls_open, |
| .url_read = tls_read, |
| .url_write = tls_write, |
| .url_close = tls_close, |
| .url_get_file_handle = tls_get_file_handle, |
| .url_get_short_seek = tls_get_short_seek, |
| .priv_data_size = sizeof(TLSContext), |
| .flags = URL_PROTOCOL_FLAG_NETWORK, |
| .priv_data_class = &tls_class, |
| }; |