Add support for SRTP
This commit is contained in:
Marvin W
parent
9fed5ea865
commit
b393d41601
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@ -10,6 +10,7 @@ SOURCES
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"src/cipher.vala"
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"src/cipher_converter.vala"
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"src/error.vala"
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"src/random.vala"
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CUSTOM_VAPIS
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"${CMAKE_CURRENT_SOURCE_DIR}/vapi/gcrypt.vapi"
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PACKAGES
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5
plugins/crypto-vala/src/random.vala
Normal file
5
plugins/crypto-vala/src/random.vala
Normal file
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@ -0,0 +1,5 @@
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namespace Crypto {
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public static void randomize(uint8[] buffer) {
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GCrypt.Random.randomize(buffer);
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}
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}
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@ -18,18 +18,20 @@ SOURCES
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src/video_widget.vala
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src/register_plugin.vala
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CUSTOM_VAPIS
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${CMAKE_BINARY_DIR}/exports/crypto-vala.vapi
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${CMAKE_BINARY_DIR}/exports/xmpp-vala.vapi
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${CMAKE_BINARY_DIR}/exports/dino.vapi
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${CMAKE_BINARY_DIR}/exports/qlite.vapi
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${CMAKE_CURRENT_SOURCE_DIR}/src/srtp.vapi
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PACKAGES
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${RTP_PACKAGES}
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OPTIONS
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--vapidir=${CMAKE_CURRENT_SOURCE_DIR}/vapi
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)
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add_definitions(${VALA_CFLAGS} -DG_LOG_DOMAIN="rtp")
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add_library(rtp SHARED ${RTP_VALA_C})
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target_link_libraries(rtp libdino ${RTP_PACKAGES})
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add_definitions(${VALA_CFLAGS} -DG_LOG_DOMAIN="rtp" -I${CMAKE_CURRENT_SOURCE_DIR}/src)
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add_library(rtp SHARED ${RTP_VALA_C} src/srtp.c)
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target_link_libraries(rtp libdino crypto-vala ${RTP_PACKAGES})
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set_target_properties(rtp PROPERTIES PREFIX "")
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set_target_properties(rtp PROPERTIES LIBRARY_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/plugins/)
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@ -200,65 +200,23 @@ public class Dino.Plugins.Rtp.Module : JingleRtp.Module {
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plugin.close_stream(rtp_stream);
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}
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// public uint32 get_session_id(string id) {
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// return (uint32) id.split("-")[0].to_int();
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// }
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//
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// public string create_feed(string media, bool incoming) {
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// init();
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// string id = random_uuid();
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// if (media == "audio") {
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// id = "0-" + id;
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// } else {
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// id = "1-" + id;
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// }
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// MediaDevice? device = plugin.get_preferred_device(media, incoming);
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// Feed feed;
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// if (incoming) {
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// if (media == "audio") {
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// feed = new IncomingAudioFeed(id, this, device);
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// } else if (media == "video") {
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// feed = new IncomingVideoFeed(id, this, device);
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// } else {
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// critical("Incoming feed of media '%s' not supported", media);
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// return id;
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// }
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// } else {
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// if (media == "audio") {
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// string? matching_incoming_feed_id = null;
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// foreach (Feed match in plugin.feeds.values) {
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// if (match is IncomingAudioFeed) {
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// matching_incoming_feed_id = match.id;
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// }
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// }
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// feed = new OutgoingAudioFeed(id, this, device);
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// } else if (media == "video") {
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// feed = new OutgoingVideoFeed(id, this, device);
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// } else {
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// critical("Outgoing feed of media '%s' not supported", media);
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// return id;
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// }
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// }
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// plugin.add_feed(id, feed);
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// return id;
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// }
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//
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// public void connect_feed(string id, JingleRtp.PayloadType payload, Jingle.DatagramConnection connection) {
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// if (!plugin.feeds.has_key(id)) {
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// critical("Tried to connect feed with id %s, but no such feed found", id);
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// return;
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// }
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// Feed feed = plugin.feeds[id];
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// feed.connect(payload, connection);
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// }
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//
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// public void destroy_feed(string id) {
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// if (!plugin.feeds.has_key(id)) {
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// critical("Tried to destroy feed with id %s, but no such feed found", id);
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// return;
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// }
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// Feed feed = plugin.feeds[id];
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// feed.destroy();
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// plugin.feeds.remove(id);
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// }
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public override JingleRtp.Crypto? generate_local_crypto() {
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uint8[] keyAndSalt = new uint8[30];
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Crypto.randomize(keyAndSalt);
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return JingleRtp.Crypto.create(JingleRtp.Crypto.AES_CM_128_HMAC_SHA1_80, keyAndSalt);
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}
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public override JingleRtp.Crypto? pick_remote_crypto(Gee.List<JingleRtp.Crypto> cryptos) {
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foreach (JingleRtp.Crypto crypto in cryptos) {
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if (crypto.is_valid) return crypto;
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}
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return null;
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}
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public override JingleRtp.Crypto? pick_local_crypto(JingleRtp.Crypto? remote) {
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if (remote == null || !remote.is_valid) return null;
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uint8[] keyAndSalt = new uint8[30];
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Crypto.randomize(keyAndSalt);
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return remote.rekey(keyAndSalt);
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}
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}
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836
plugins/rtp/src/srtp.c
Normal file
836
plugins/rtp/src/srtp.c
Normal file
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@ -0,0 +1,836 @@
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/*
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* Secure RTP with libgcrypt
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* Copyright (C) 2007 Rémi Denis-Courmont
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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/* TODO:
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* Useless stuff (because nothing depends on it):
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* - non-nul key derivation rate
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* - MKI payload
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*/
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#ifdef HAVE_CONFIG_H
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# include <config.h>
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#endif
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#include <stdint.h>
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#include <stddef.h>
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#include "srtp.h"
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#include <stdbool.h>
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#include <stdlib.h>
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#include <assert.h>
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#include <errno.h>
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#include <gcrypt.h>
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#ifdef _WIN32
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# include <winsock2.h>
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#else
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# include <netinet/in.h>
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#endif
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#define debug( ... ) (void)0
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typedef struct srtp_proto_t
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{
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gcry_cipher_hd_t cipher;
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gcry_md_hd_t mac;
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uint64_t window;
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uint32_t salt[4];
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} srtp_proto_t;
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struct srtp_session_t
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{
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srtp_proto_t rtp;
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srtp_proto_t rtcp;
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unsigned flags;
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unsigned kdr;
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uint32_t rtcp_index;
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uint32_t rtp_roc;
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uint16_t rtp_seq;
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uint16_t rtp_rcc;
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uint8_t tag_len;
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};
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enum
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{
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SRTP_CRYPT,
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SRTP_AUTH,
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SRTP_SALT,
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SRTCP_CRYPT,
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SRTCP_AUTH,
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SRTCP_SALT
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};
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static inline unsigned rcc_mode (const srtp_session_t *s)
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{
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return (s->flags >> 4) & 3;
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}
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static void proto_destroy (srtp_proto_t *p)
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{
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gcry_md_close (p->mac);
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gcry_cipher_close (p->cipher);
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}
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/**
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* Releases all resources associated with a Secure RTP session.
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*/
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void srtp_destroy (srtp_session_t *s)
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{
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assert (s != NULL);
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proto_destroy (&s->rtcp);
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proto_destroy (&s->rtp);
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free (s);
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}
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static int proto_create (srtp_proto_t *p, int gcipher, int gmd)
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{
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if (gcry_cipher_open (&p->cipher, gcipher, GCRY_CIPHER_MODE_CTR, 0) == 0)
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{
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if (gcry_md_open (&p->mac, gmd, GCRY_MD_FLAG_HMAC) == 0)
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return 0;
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gcry_cipher_close (p->cipher);
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}
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return -1;
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}
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/**
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* Allocates a Secure RTP one-way session.
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* The same session cannot be used both ways because this would confuse
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* internal cryptographic counters; it is however of course feasible to open
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* multiple simultaneous sessions with the same master key.
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*
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* @param encr encryption algorithm number
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* @param auth authentication algortihm number
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* @param tag_len authentication tag byte length (NOT including RCC)
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* @param flags OR'ed optional flags.
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*
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* @return NULL in case of error
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*/
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srtp_session_t *
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srtp_create (int encr, int auth, unsigned tag_len, int prf, unsigned flags)
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{
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if ((flags & ~SRTP_FLAGS_MASK))
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return NULL;
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int cipher, md;
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switch (encr)
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{
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case SRTP_ENCR_NULL:
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cipher = GCRY_CIPHER_NONE;
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break;
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case SRTP_ENCR_AES_CM:
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cipher = GCRY_CIPHER_AES;
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break;
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default:
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return NULL;
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}
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switch (auth)
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{
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case SRTP_AUTH_NULL:
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md = GCRY_MD_NONE;
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break;
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case SRTP_AUTH_HMAC_SHA1:
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md = GCRY_MD_SHA1;
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break;
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default:
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return NULL;
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}
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if (tag_len > gcry_md_get_algo_dlen (md))
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return NULL;
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if (prf != SRTP_PRF_AES_CM)
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return NULL;
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srtp_session_t *s = malloc (sizeof (*s));
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if (s == NULL)
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return NULL;
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memset (s, 0, sizeof (*s));
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s->flags = flags;
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s->tag_len = tag_len;
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s->rtp_rcc = 1; /* Default RCC rate */
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if (rcc_mode (s))
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{
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if (tag_len < 4)
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goto error;
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}
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if (proto_create (&s->rtp, cipher, md) == 0)
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{
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if (proto_create (&s->rtcp, cipher, md) == 0)
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return s;
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proto_destroy (&s->rtp);
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}
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error:
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free (s);
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return NULL;
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}
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/**
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* Counter Mode encryption/decryption (ctr length = 16 bytes)
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* with non-padded (truncated) text
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*/
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static int
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do_ctr_crypt (gcry_cipher_hd_t hd, const void *ctr, uint8_t *data, size_t len)
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{
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const size_t ctrlen = 16;
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div_t d = div (len, ctrlen);
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if (gcry_cipher_setctr (hd, ctr, ctrlen)
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|| gcry_cipher_encrypt (hd, data, d.quot * ctrlen, NULL, 0))
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return -1;
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if (d.rem)
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{
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/* Truncated last block */
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uint8_t dummy[ctrlen];
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data += d.quot * ctrlen;
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memcpy (dummy, data, d.rem);
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memset (dummy + d.rem, 0, ctrlen - d.rem);
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if (gcry_cipher_encrypt (hd, dummy, ctrlen, data, ctrlen))
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return -1;
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memcpy (data, dummy, d.rem);
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}
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return 0;
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}
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/**
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* AES-CM key derivation (saltlen = 14 bytes)
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*/
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static int
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do_derive (gcry_cipher_hd_t prf, const void *salt,
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const uint8_t *r, size_t rlen, uint8_t label,
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void *out, size_t outlen)
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{
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uint8_t iv[16];
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memcpy (iv, salt, 14);
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iv[14] = iv[15] = 0;
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assert (rlen < 14);
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iv[13 - rlen] ^= label;
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for (size_t i = 0; i < rlen; i++)
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iv[sizeof (iv) - rlen + i] ^= r[i];
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memset (out, 0, outlen);
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return do_ctr_crypt (prf, iv, out, outlen);
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}
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/**
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* Sets (or resets) the master key and master salt for a SRTP session.
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* This must be done at least once before using srtp_send(), srtp_recv(),
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* srtcp_send() or srtcp_recv(). Also, rekeying is required every
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* 2^48 RTP packets or 2^31 RTCP packets (whichever comes first),
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* otherwise the protocol security might be broken.
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*
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* @return 0 on success, in case of error:
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* EINVAL invalid or unsupported key/salt sizes combination
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*/
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int
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srtp_setkey (srtp_session_t *s, const void *key, size_t keylen,
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const void *salt, size_t saltlen)
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{
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/* SRTP/SRTCP cipher/salt/MAC keys derivation */
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gcry_cipher_hd_t prf;
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uint8_t r[6], keybuf[20];
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if (saltlen != 14)
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return EINVAL;
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if (gcry_cipher_open (&prf, GCRY_CIPHER_AES, GCRY_CIPHER_MODE_CTR, 0)
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|| gcry_cipher_setkey (prf, key, keylen))
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return EINVAL;
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/* SRTP key derivation */
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#if 0
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if (s->kdr != 0)
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{
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uint64_t index = (((uint64_t)s->rtp_roc) << 16) | s->rtp_seq;
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index /= s->kdr;
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for (int i = sizeof (r) - 1; i >= 0; i--)
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{
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r[i] = index & 0xff;
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index = index >> 8;
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}
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}
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else
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#endif
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memset (r, 0, sizeof (r));
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if (do_derive (prf, salt, r, 6, SRTP_CRYPT, keybuf, 16)
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|| gcry_cipher_setkey (s->rtp.cipher, keybuf, 16)
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|| do_derive (prf, salt, r, 6, SRTP_AUTH, keybuf, 20)
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|| gcry_md_setkey (s->rtp.mac, keybuf, 20)
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|| do_derive (prf, salt, r, 6, SRTP_SALT, s->rtp.salt, 14))
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return -1;
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/* SRTCP key derivation */
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memcpy (r, &(uint32_t){ htonl (s->rtcp_index) }, 4);
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if (do_derive (prf, salt, r, 4, SRTCP_CRYPT, keybuf, 16)
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|| gcry_cipher_setkey (s->rtcp.cipher, keybuf, 16)
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|| do_derive (prf, salt, r, 4, SRTCP_AUTH, keybuf, 20)
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|| gcry_md_setkey (s->rtcp.mac, keybuf, 20)
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|| do_derive (prf, salt, r, 4, SRTCP_SALT, s->rtcp.salt, 14))
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return -1;
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(void)gcry_cipher_close (prf);
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return 0;
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}
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static int hexdigit (char c)
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{
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if ((c >= '0') && (c <= '9'))
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return c - '0';
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if ((c >= 'A') && (c <= 'F'))
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return c - 'A' + 0xA;
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if ((c >= 'a') && (c <= 'f'))
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return c - 'a' + 0xa;
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return -1;
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}
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static ssize_t hexstring (const char *in, uint8_t *out, size_t outlen)
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{
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size_t inlen = strlen (in);
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if ((inlen > (2 * outlen)) || (inlen & 1))
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return -1;
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for (size_t i = 0; i < inlen; i += 2)
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{
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int a = hexdigit (in[i]), b = hexdigit (in[i + 1]);
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if ((a == -1) || (b == -1))
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return -1;
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out[i / 2] = (a << 4) | b;
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}
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return inlen / 2;
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}
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/**
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* Sets (or resets) the master key and master salt for a SRTP session
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* from hexadecimal strings. See also srtp_setkey().
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*
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* @return 0 on success, in case of error:
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* EINVAL invalid or unsupported key/salt sizes combination
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||||
*/
|
||||
int
|
||||
srtp_setkeystring (srtp_session_t *s, const char *key, const char *salt)
|
||||
{
|
||||
uint8_t bkey[16]; /* TODO/NOTE: hard-coded for AES */
|
||||
uint8_t bsalt[14]; /* TODO/NOTE: hard-coded for the PRF-AES-CM */
|
||||
ssize_t bkeylen = hexstring (key, bkey, sizeof (bkey));
|
||||
ssize_t bsaltlen = hexstring (salt, bsalt, sizeof (bsalt));
|
||||
|
||||
if ((bkeylen == -1) || (bsaltlen == -1))
|
||||
return EINVAL;
|
||||
return srtp_setkey (s, bkey, bkeylen, bsalt, bsaltlen) ? EINVAL : 0;
|
||||
}
|
||||
|
||||
/**
|
||||
* Sets Roll-over-Counter Carry (RCC) rate for the SRTP session. If not
|
||||
* specified (through this function), the default rate of ONE is assumed
|
||||
* (i.e. every RTP packets will carry the RoC). RCC rate is ignored if none
|
||||
* of the RCC mode has been selected.
|
||||
*
|
||||
* The RCC mode is selected through one of these flags for srtp_create():
|
||||
* SRTP_RCC_MODE1: integrity protection only for RoC carrying packets
|
||||
* SRTP_RCC_MODE2: integrity protection for all packets
|
||||
* SRTP_RCC_MODE3: no integrity protection
|
||||
*
|
||||
* RCC mode 3 is insecure. Compared to plain RTP, it provides confidentiality
|
||||
* (through encryption) but is much more prone to DoS. It can only be used if
|
||||
* anti-spoofing protection is provided by lower network layers (e.g. IPsec,
|
||||
* or trusted routers and proper source address filtering).
|
||||
*
|
||||
* If RCC rate is 1, RCC mode 1 and 2 are functionally identical.
|
||||
*
|
||||
* @param rate RoC Carry rate (MUST NOT be zero)
|
||||
*/
|
||||
void srtp_setrcc_rate (srtp_session_t *s, uint16_t rate)
|
||||
{
|
||||
assert (rate != 0);
|
||||
s->rtp_rcc = rate;
|
||||
}
|
||||
|
||||
|
||||
/** AES-CM for RTP (salt = 14 bytes + 2 nul bytes) */
|
||||
static int
|
||||
rtp_crypt (gcry_cipher_hd_t hd, uint32_t ssrc, uint32_t roc, uint16_t seq,
|
||||
const uint32_t *salt, uint8_t *data, size_t len)
|
||||
{
|
||||
/* Determines cryptographic counter (IV) */
|
||||
uint32_t counter[4];
|
||||
counter[0] = salt[0];
|
||||
counter[1] = salt[1] ^ ssrc;
|
||||
counter[2] = salt[2] ^ htonl (roc);
|
||||
counter[3] = salt[3] ^ htonl (seq << 16);
|
||||
|
||||
/* Encryption */
|
||||
return do_ctr_crypt (hd, counter, data, len);
|
||||
}
|
||||
|
||||
|
||||
/** Determines SRTP Roll-Over-Counter (in host-byte order) */
|
||||
static uint32_t
|
||||
srtp_compute_roc (const srtp_session_t *s, uint16_t seq)
|
||||
{
|
||||
uint32_t roc = s->rtp_roc;
|
||||
|
||||
if (((seq - s->rtp_seq) & 0xffff) < 0x8000)
|
||||
{
|
||||
/* Sequence is ahead, good */
|
||||
if (seq < s->rtp_seq)
|
||||
roc++; /* Sequence number wrap */
|
||||
}
|
||||
else
|
||||
{
|
||||
/* Sequence is late, bad */
|
||||
if (seq > s->rtp_seq)
|
||||
roc--; /* Wrap back */
|
||||
}
|
||||
return roc;
|
||||
}
|
||||
|
||||
|
||||
/** Returns RTP sequence (in host-byte order) */
|
||||
static inline uint16_t rtp_seq (const uint8_t *buf)
|
||||
{
|
||||
return (buf[2] << 8) | buf[3];
|
||||
}
|
||||
|
||||
|
||||
/** Message Authentication and Integrity for RTP */
|
||||
static const uint8_t *
|
||||
rtp_digest (gcry_md_hd_t md, const uint8_t *data, size_t len,
|
||||
uint32_t roc)
|
||||
{
|
||||
gcry_md_reset (md);
|
||||
gcry_md_write (md, data, len);
|
||||
gcry_md_write (md, &(uint32_t){ htonl (roc) }, 4);
|
||||
return gcry_md_read (md, 0);
|
||||
}
|
||||
|
||||
|
||||
/**
|
||||
* Encrypts/decrypts a RTP packet and updates SRTP context
|
||||
* (CTR block cypher mode of operation has identical encryption and
|
||||
* decryption function).
|
||||
*
|
||||
* @param buf RTP packet to be en-/decrypted
|
||||
* @param len RTP packet length
|
||||
*
|
||||
* @return 0 on success, in case of error:
|
||||
* EINVAL malformatted RTP packet
|
||||
* EACCES replayed packet or out-of-window or sync lost
|
||||
*/
|
||||
static int srtp_crypt (srtp_session_t *s, uint8_t *buf, size_t len)
|
||||
{
|
||||
assert (s != NULL);
|
||||
assert (len >= 12u);
|
||||
|
||||
if ((buf[0] >> 6) != 2)
|
||||
return EINVAL;
|
||||
|
||||
/* Computes encryption offset */
|
||||
uint16_t offset = 12;
|
||||
offset += (buf[0] & 0xf) * 4; // skips CSRC
|
||||
|
||||
if (buf[0] & 0x10)
|
||||
{
|
||||
uint16_t extlen;
|
||||
|
||||
offset += 4;
|
||||
if (len < offset)
|
||||
return EINVAL;
|
||||
|
||||
memcpy (&extlen, buf + offset - 2, 2);
|
||||
offset += htons (extlen); // skips RTP extension header
|
||||
}
|
||||
|
||||
if (len < offset)
|
||||
return EINVAL;
|
||||
|
||||
/* Determines RTP 48-bits counter and SSRC */
|
||||
uint16_t seq = rtp_seq (buf);
|
||||
uint32_t roc = srtp_compute_roc (s, seq), ssrc;
|
||||
memcpy (&ssrc, buf + 8, 4);
|
||||
|
||||
/* Updates ROC and sequence (it's safe now) */
|
||||
int16_t diff = seq - s->rtp_seq;
|
||||
if (diff > 0)
|
||||
{
|
||||
/* Sequence in the future, good */
|
||||
s->rtp.window = s->rtp.window << diff;
|
||||
s->rtp.window |= UINT64_C(1);
|
||||
s->rtp_seq = seq, s->rtp_roc = roc;
|
||||
}
|
||||
else
|
||||
{
|
||||
/* Sequence in the past/present, bad */
|
||||
diff = -diff;
|
||||
if ((diff >= 64) || ((s->rtp.window >> diff) & 1))
|
||||
return EACCES; /* Replay attack */
|
||||
s->rtp.window |= UINT64_C(1) << diff;
|
||||
}
|
||||
|
||||
/* Encrypt/Decrypt */
|
||||
if (s->flags & SRTP_UNENCRYPTED)
|
||||
return 0;
|
||||
|
||||
if (rtp_crypt (s->rtp.cipher, ssrc, roc, seq, s->rtp.salt,
|
||||
buf + offset, len - offset))
|
||||
return EINVAL;
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
|
||||
/**
|
||||
* Turns a RTP packet into a SRTP packet: encrypt it, then computes
|
||||
* the authentication tag and appends it.
|
||||
* Note that you can encrypt packet in disorder.
|
||||
*
|
||||
* @param buf RTP packet to be encrypted/digested
|
||||
* @param lenp pointer to the RTP packet length on entry,
|
||||
* set to the SRTP length on exit (undefined on non-ENOSPC error)
|
||||
* @param bufsize size (bytes) of the packet buffer
|
||||
*
|
||||
* @return 0 on success, in case of error:
|
||||
* EINVAL malformatted RTP packet or internal error
|
||||
* ENOSPC bufsize is too small to add authentication tag
|
||||
* (<lenp> will hold the required byte size)
|
||||
* EACCES packet would trigger a replay error on receiver
|
||||
*/
|
||||
int
|
||||
srtp_send (srtp_session_t *s, uint8_t *buf, size_t *lenp, size_t bufsize)
|
||||
{
|
||||
size_t len = *lenp;
|
||||
size_t tag_len;
|
||||
size_t roc_len = 0;
|
||||
|
||||
/* Compute required buffer size */
|
||||
if (len < 12u)
|
||||
return EINVAL;
|
||||
|
||||
if (!(s->flags & SRTP_UNAUTHENTICATED))
|
||||
{
|
||||
tag_len = s->tag_len;
|
||||
|
||||
if (rcc_mode (s))
|
||||
{
|
||||
assert (tag_len >= 4);
|
||||
assert (s->rtp_rcc != 0);
|
||||
if ((rtp_seq (buf) % s->rtp_rcc) == 0)
|
||||
{
|
||||
roc_len = 4;
|
||||
if (rcc_mode (s) == 3)
|
||||
tag_len = 0; /* RCC mode 3 -> no auth*/
|
||||
else
|
||||
tag_len -= 4; /* RCC mode 1 or 2 -> auth*/
|
||||
}
|
||||
else
|
||||
{
|
||||
if (rcc_mode (s) & 1)
|
||||
tag_len = 0; /* RCC mode 1 or 3 -> no auth */
|
||||
}
|
||||
}
|
||||
|
||||
*lenp = len + roc_len + tag_len;
|
||||
}
|
||||
else
|
||||
tag_len = 0;
|
||||
|
||||
if (bufsize < *lenp)
|
||||
return ENOSPC;
|
||||
|
||||
/* Encrypt payload */
|
||||
int val = srtp_crypt (s, buf, len);
|
||||
if (val)
|
||||
return val;
|
||||
|
||||
/* Authenticate payload */
|
||||
if (!(s->flags & SRTP_UNAUTHENTICATED))
|
||||
{
|
||||
uint32_t roc = srtp_compute_roc (s, rtp_seq (buf));
|
||||
const uint8_t *tag = rtp_digest (s->rtp.mac, buf, len, roc);
|
||||
|
||||
if (roc_len)
|
||||
{
|
||||
memcpy (buf + len, &(uint32_t){ htonl (s->rtp_roc) }, 4);
|
||||
len += 4;
|
||||
}
|
||||
memcpy (buf + len, tag, tag_len);
|
||||
#if 0
|
||||
printf ("Sent : 0x");
|
||||
for (unsigned i = 0; i < tag_len; i++)
|
||||
printf ("%02x", tag[i]);
|
||||
puts ("");
|
||||
#endif
|
||||
}
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
|
||||
/**
|
||||
* Turns a SRTP packet into a RTP packet: authenticates the packet,
|
||||
* then decrypts it.
|
||||
*
|
||||
* @param buf RTP packet to be digested/decrypted
|
||||
* @param lenp pointer to the SRTP packet length on entry,
|
||||
* set to the RTP length on exit (undefined in case of error)
|
||||
*
|
||||
* @return 0 on success, in case of error:
|
||||
* EINVAL malformatted SRTP packet
|
||||
* EACCES authentication failed (spoofed packet or out-of-sync)
|
||||
*/
|
||||
int
|
||||
srtp_recv (srtp_session_t *s, uint8_t *buf, size_t *lenp)
|
||||
{
|
||||
size_t len = *lenp;
|
||||
if (len < 12u)
|
||||
return EINVAL;
|
||||
|
||||
if (!(s->flags & SRTP_UNAUTHENTICATED))
|
||||
{
|
||||
size_t tag_len = s->tag_len, roc_len = 0;
|
||||
if (rcc_mode (s))
|
||||
{
|
||||
if ((rtp_seq (buf) % s->rtp_rcc) == 0)
|
||||
{
|
||||
roc_len = 4;
|
||||
if (rcc_mode (s) == 3)
|
||||
tag_len = 0;
|
||||
else
|
||||
tag_len -= 4;
|
||||
}
|
||||
else
|
||||
{
|
||||
if (rcc_mode (s) & 1)
|
||||
tag_len = 0; // RCC mode 1 or 3: no auth
|
||||
}
|
||||
}
|
||||
|
||||
if (len < (12u + roc_len + tag_len))
|
||||
return EINVAL;
|
||||
len -= roc_len + tag_len;
|
||||
|
||||
uint32_t roc = srtp_compute_roc (s, rtp_seq (buf)), rcc;
|
||||
if (roc_len)
|
||||
{
|
||||
assert (roc_len == 4);
|
||||
memcpy (&rcc, buf + len, 4);
|
||||
rcc = ntohl (rcc);
|
||||
}
|
||||
else
|
||||
rcc = roc;
|
||||
|
||||
const uint8_t *tag = rtp_digest (s->rtp.mac, buf, len, rcc);
|
||||
#if 0
|
||||
printf ("Computed: 0x");
|
||||
for (unsigned i = 0; i < tag_len; i++)
|
||||
printf ("%02x", tag[i]);
|
||||
printf ("\nReceived: 0x");
|
||||
for (unsigned i = 0; i < tag_len; i++)
|
||||
printf ("%02x", buf[len + roc_len + i]);
|
||||
puts ("");
|
||||
#endif
|
||||
if (memcmp (buf + len + roc_len, tag, tag_len))
|
||||
return EACCES;
|
||||
|
||||
if (roc_len)
|
||||
{
|
||||
/* Authenticated packet carried a Roll-Over-Counter */
|
||||
s->rtp_roc += rcc - roc;
|
||||
assert (srtp_compute_roc (s, rtp_seq (buf)) == rcc);
|
||||
}
|
||||
*lenp = len;
|
||||
}
|
||||
|
||||
return srtp_crypt (s, buf, len);
|
||||
}
|
||||
|
||||
|
||||
/** AES-CM for RTCP (salt = 14 bytes + 2 nul bytes) */
|
||||
static int
|
||||
rtcp_crypt (gcry_cipher_hd_t hd, uint32_t ssrc, uint32_t index,
|
||||
const uint32_t *salt, uint8_t *data, size_t len)
|
||||
{
|
||||
return rtp_crypt (hd, ssrc, index >> 16, index & 0xffff, salt, data, len);
|
||||
}
|
||||
|
||||
|
||||
/** Message Authentication and Integrity for RTCP */
|
||||
static const uint8_t *
|
||||
rtcp_digest (gcry_md_hd_t md, const void *data, size_t len)
|
||||
{
|
||||
gcry_md_reset (md);
|
||||
gcry_md_write (md, data, len);
|
||||
return gcry_md_read (md, 0);
|
||||
}
|
||||
|
||||
|
||||
/**
|
||||
* Encrypts/decrypts a RTCP packet and updates SRTCP context
|
||||
* (CTR block cypher mode of operation has identical encryption and
|
||||
* decryption function).
|
||||
*
|
||||
* @param buf RTCP packet to be en-/decrypted
|
||||
* @param len RTCP packet length
|
||||
*
|
||||
* @return 0 on success, in case of error:
|
||||
* EINVAL malformatted RTCP packet
|
||||
*/
|
||||
static int srtcp_crypt (srtp_session_t *s, uint8_t *buf, size_t len)
|
||||
{
|
||||
assert (s != NULL);
|
||||
|
||||
/* 8-bytes unencrypted header, and 4-bytes unencrypted footer */
|
||||
if ((len < 12) || ((buf[0] >> 6) != 2))
|
||||
return EINVAL;
|
||||
|
||||
uint32_t index;
|
||||
memcpy (&index, buf + len, 4);
|
||||
index = ntohl (index);
|
||||
if (((index >> 31) != 0) != ((s->flags & SRTCP_UNENCRYPTED) == 0))
|
||||
return EINVAL; // E-bit mismatch
|
||||
|
||||
index &= ~(1 << 31); // clear E-bit for counter
|
||||
|
||||
/* Updates SRTCP index (safe here) */
|
||||
int32_t diff = index - s->rtcp_index;
|
||||
if (diff > 0)
|
||||
{
|
||||
/* Packet in the future, good */
|
||||
s->rtcp.window = s->rtcp.window << diff;
|
||||
s->rtcp.window |= UINT64_C(1);
|
||||
s->rtcp_index = index;
|
||||
}
|
||||
else
|
||||
{
|
||||
/* Packet in the past/present, bad */
|
||||
diff = -diff;
|
||||
if ((diff >= 64) || ((s->rtcp.window >> diff) & 1))
|
||||
return EACCES; // replay attack!
|
||||
s->rtp.window |= UINT64_C(1) << diff;
|
||||
}
|
||||
|
||||
/* Crypts SRTCP */
|
||||
if (s->flags & SRTCP_UNENCRYPTED)
|
||||
return 0;
|
||||
|
||||
uint32_t ssrc;
|
||||
memcpy (&ssrc, buf + 4, 4);
|
||||
|
||||
if (rtcp_crypt (s->rtcp.cipher, ssrc, index, s->rtp.salt,
|
||||
buf + 8, len - 8))
|
||||
return EINVAL;
|
||||
return 0;
|
||||
}
|
||||
|
||||
|
||||
/**
|
||||
* Turns a RTCP packet into a SRTCP packet: encrypt it, then computes
|
||||
* the authentication tag and appends it.
|
||||
*
|
||||
* @param buf RTCP packet to be encrypted/digested
|
||||
* @param lenp pointer to the RTCP packet length on entry,
|
||||
* set to the SRTCP length on exit (undefined in case of error)
|
||||
* @param bufsize size (bytes) of the packet buffer
|
||||
*
|
||||
* @return 0 on success, in case of error:
|
||||
* EINVAL malformatted RTCP packet or internal error
|
||||
* ENOSPC bufsize is too small (to add index and authentication tag)
|
||||
*/
|
||||
int
|
||||
srtcp_send (srtp_session_t *s, uint8_t *buf, size_t *lenp, size_t bufsize)
|
||||
{
|
||||
size_t len = *lenp;
|
||||
if (bufsize < (len + 4 + s->tag_len))
|
||||
return ENOSPC;
|
||||
|
||||
uint32_t index = ++s->rtcp_index;
|
||||
if (index >> 31)
|
||||
s->rtcp_index = index = 0; /* 31-bit wrap */
|
||||
|
||||
if ((s->flags & SRTCP_UNENCRYPTED) == 0)
|
||||
index |= 0x80000000; /* Set Encrypted bit */
|
||||
memcpy (buf + len, &(uint32_t){ htonl (index) }, 4);
|
||||
|
||||
int val = srtcp_crypt (s, buf, len);
|
||||
if (val)
|
||||
return val;
|
||||
|
||||
len += 4; /* Digests SRTCP index too */
|
||||
|
||||
const uint8_t *tag = rtcp_digest (s->rtcp.mac, buf, len);
|
||||
memcpy (buf + len, tag, s->tag_len);
|
||||
*lenp = len + s->tag_len;
|
||||
return 0;
|
||||
}
|
||||
|
||||
|
||||
/**
|
||||
* Turns a SRTCP packet into a RTCP packet: authenticates the packet,
|
||||
* then decrypts it.
|
||||
*
|
||||
* @param buf RTCP packet to be digested/decrypted
|
||||
* @param lenp pointer to the SRTCP packet length on entry,
|
||||
* set to the RTCP length on exit (undefined in case of error)
|
||||
*
|
||||
* @return 0 on success, in case of error:
|
||||
* EINVAL malformatted SRTCP packet
|
||||
* EACCES authentication failed (spoofed packet or out-of-sync)
|
||||
*/
|
||||
int
|
||||
srtcp_recv (srtp_session_t *s, uint8_t *buf, size_t *lenp)
|
||||
{
|
||||
size_t len = *lenp;
|
||||
|
||||
if (len < (4u + s->tag_len))
|
||||
return EINVAL;
|
||||
len -= s->tag_len;
|
||||
|
||||
const uint8_t *tag = rtcp_digest (s->rtcp.mac, buf, len);
|
||||
if (memcmp (buf + len, tag, s->tag_len))
|
||||
return EACCES;
|
||||
|
||||
len -= 4; /* Remove SRTCP index before decryption */
|
||||
*lenp = len;
|
||||
return srtcp_crypt (s, buf, len);
|
||||
}
|
||||
82
plugins/rtp/src/srtp.h
Normal file
82
plugins/rtp/src/srtp.h
Normal file
|
|
@ -0,0 +1,82 @@
|
|||
/*
|
||||
* Secure RTP with libgcrypt
|
||||
* Copyright (C) 2007 Rémi Denis-Courmont
|
||||
*
|
||||
* This library 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.
|
||||
*
|
||||
* This library 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 this library; if not, write to the Free Software
|
||||
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
|
||||
****************************************************************************/
|
||||
|
||||
#ifndef LIBVLC_SRTP_H
|
||||
# define LIBVLC_SRTP_H 1
|
||||
#include <stdint.h>
|
||||
|
||||
typedef struct srtp_session_t srtp_session_t;
|
||||
|
||||
enum
|
||||
{
|
||||
SRTP_UNENCRYPTED=0x1, //< do not encrypt SRTP packets
|
||||
SRTCP_UNENCRYPTED=0x2, //< do not encrypt SRTCP packets
|
||||
SRTP_UNAUTHENTICATED=0x4, //< authenticate only SRTCP packets
|
||||
|
||||
SRTP_RCC_MODE1=0x10, //< use Roll-over-Counter Carry mode 1
|
||||
SRTP_RCC_MODE2=0x20, //< use Roll-over-Counter Carry mode 2
|
||||
SRTP_RCC_MODE3=0x30, //< use Roll-over-Counter Carry mode 3 (insecure)
|
||||
|
||||
SRTP_FLAGS_MASK=0x37 //< mask for valid flags
|
||||
};
|
||||
|
||||
/** SRTP encryption algorithms (ciphers); same values as MIKEY */
|
||||
enum
|
||||
{
|
||||
SRTP_ENCR_NULL=0, //< no encryption
|
||||
SRTP_ENCR_AES_CM=1, //< AES counter mode
|
||||
SRTP_ENCR_AES_F8=2, //< AES F8 mode (not implemented)
|
||||
};
|
||||
|
||||
/** SRTP authenticaton algorithms; same values as MIKEY */
|
||||
enum
|
||||
{
|
||||
SRTP_AUTH_NULL=0, //< no authentication code
|
||||
SRTP_AUTH_HMAC_SHA1=1, //< HMAC-SHA1
|
||||
};
|
||||
|
||||
/** SRTP pseudo random function; same values as MIKEY */
|
||||
enum
|
||||
{
|
||||
SRTP_PRF_AES_CM=0, //< AES counter mode
|
||||
};
|
||||
|
||||
# ifdef __cplusplus
|
||||
extern "C" {
|
||||
# endif
|
||||
|
||||
srtp_session_t *srtp_create (int encr, int auth, unsigned tag_len, int prf,
|
||||
unsigned flags);
|
||||
void srtp_destroy (srtp_session_t *s);
|
||||
|
||||
int srtp_setkey (srtp_session_t *s, const void *key, size_t keylen,
|
||||
const void *salt, size_t saltlen);
|
||||
int srtp_setkeystring (srtp_session_t *s, const char *key, const char *salt);
|
||||
|
||||
void srtp_setrcc_rate (srtp_session_t *s, uint16_t rate);
|
||||
|
||||
int srtp_send (srtp_session_t *s, uint8_t *buf, size_t *lenp, size_t maxsize);
|
||||
int srtp_recv (srtp_session_t *s, uint8_t *buf, size_t *lenp);
|
||||
int srtcp_send (srtp_session_t *s, uint8_t *buf, size_t *lenp, size_t maxsiz);
|
||||
int srtcp_recv (srtp_session_t *s, uint8_t *buf, size_t *lenp);
|
||||
|
||||
# ifdef __cplusplus
|
||||
}
|
||||
# endif
|
||||
#endif
|
||||
103
plugins/rtp/src/srtp.vapi
Normal file
103
plugins/rtp/src/srtp.vapi
Normal file
|
|
@ -0,0 +1,103 @@
|
|||
[Compact]
|
||||
[CCode (cname = "srtp_session_t", free_function = "srtp_destroy", cheader_filename="srtp.h")]
|
||||
public class Dino.Plugins.Rtp.SrtpSession {
|
||||
[CCode (cname = "srtp_create")]
|
||||
public SrtpSession(SrtpEncryption encr, SrtpAuthentication auth, uint tag_len, SrtpPrf prf, SrtpFlags flags);
|
||||
[CCode (cname = "srtp_setkey")]
|
||||
public int setkey(uint8[] key, uint8[] salt);
|
||||
[CCode (cname = "srtp_setkeystring")]
|
||||
public int setkeystring(string key, string salt);
|
||||
[CCode (cname = "srtp_setrcc_rate")]
|
||||
public void setrcc_rate(uint16 rate);
|
||||
|
||||
[CCode (cname = "srtp_send")]
|
||||
private int rtp_send([CCode (array_length = false)] uint8[] buf, ref size_t len, size_t maxsize);
|
||||
[CCode (cname = "srtcp_send")]
|
||||
private int rtcp_send([CCode (array_length = false)] uint8[] buf, ref size_t len, size_t maxsize);
|
||||
[CCode (cname = "srtp_recv")]
|
||||
private int rtp_recv([CCode (array_length = false)] uint8[] buf, ref size_t len);
|
||||
[CCode (cname = "srtcp_recv")]
|
||||
private int rtcp_recv([CCode (array_length = false)] uint8[] buf, ref size_t len);
|
||||
|
||||
public uint8[] encrypt_rtp(uint8[] input, uint tag_len = 10) throws GLib.Error {
|
||||
uint8[] buf = new uint8[input.length+tag_len];
|
||||
GLib.Memory.copy(buf, input, input.length);
|
||||
size_t buf_use = input.length;
|
||||
int res = rtp_send(buf, ref buf_use, buf.length);
|
||||
if (res != 0) {
|
||||
throw new GLib.Error(-1, res, "RTP encrypt failed");
|
||||
}
|
||||
uint8[] ret = new uint8[buf_use];
|
||||
GLib.Memory.copy(ret, buf, buf_use);
|
||||
return ret;
|
||||
}
|
||||
|
||||
public uint8[] encrypt_rtcp(uint8[] input, uint tag_len = 10) throws GLib.Error {
|
||||
uint8[] buf = new uint8[input.length+tag_len+4];
|
||||
GLib.Memory.copy(buf, input, input.length);
|
||||
size_t buf_use = input.length;
|
||||
int res = rtcp_send(buf, ref buf_use, buf.length);
|
||||
if (res != 0) {
|
||||
throw new GLib.Error(-1, res, "RTCP encrypt failed");
|
||||
}
|
||||
uint8[] ret = new uint8[buf_use];
|
||||
GLib.Memory.copy(ret, buf, buf_use);
|
||||
return ret;
|
||||
}
|
||||
|
||||
public uint8[] decrypt_rtp(uint8[] input) throws GLib.Error {
|
||||
uint8[] buf = new uint8[input.length];
|
||||
GLib.Memory.copy(buf, input, input.length);
|
||||
size_t buf_use = input.length;
|
||||
int res = rtp_recv(buf, ref buf_use);
|
||||
if (res != 0) {
|
||||
throw new GLib.Error(-1, res, "RTP decrypt failed");
|
||||
}
|
||||
uint8[] ret = new uint8[buf_use];
|
||||
GLib.Memory.copy(ret, buf, buf_use);
|
||||
return ret;
|
||||
}
|
||||
|
||||
public uint8[] decrypt_rtcp(uint8[] input) throws GLib.Error {
|
||||
uint8[] buf = new uint8[input.length];
|
||||
GLib.Memory.copy(buf, input, input.length);
|
||||
size_t buf_use = input.length;
|
||||
int res = rtcp_recv(buf, ref buf_use);
|
||||
if (res != 0) {
|
||||
throw new GLib.Error(-1, res, "RTCP decrypt failed");
|
||||
}
|
||||
uint8[] ret = new uint8[buf_use];
|
||||
GLib.Memory.copy(ret, buf, buf_use);
|
||||
return ret;
|
||||
}
|
||||
}
|
||||
|
||||
[Flags]
|
||||
[CCode (cname = "unsigned", cprefix = "", cheader_filename="srtp.h", has_type_id = false)]
|
||||
public enum Dino.Plugins.Rtp.SrtpFlags {
|
||||
SRTP_UNENCRYPTED,
|
||||
SRTCP_UNENCRYPTED,
|
||||
SRTP_UNAUTHENTICATED,
|
||||
|
||||
SRTP_RCC_MODE1,
|
||||
SRTP_RCC_MODE2,
|
||||
SRTP_RCC_MODE3
|
||||
}
|
||||
|
||||
[CCode (cname = "int", cprefix = "SRTP_ENCR_", cheader_filename="srtp.h", has_type_id = false)]
|
||||
public enum Dino.Plugins.Rtp.SrtpEncryption {
|
||||
NULL,
|
||||
AES_CM,
|
||||
AES_F8
|
||||
}
|
||||
|
||||
[CCode (cname = "int", cprefix = "SRTP_AUTH_", cheader_filename="srtp.h", has_type_id = false)]
|
||||
public enum Dino.Plugins.Rtp.SrtpAuthentication {
|
||||
NULL,
|
||||
HMAC_SHA1
|
||||
}
|
||||
|
||||
[CCode (cname = "int", cprefix = "SRTP_PRF_", cheader_filename="srtp.h", has_type_id = false)]
|
||||
public enum Dino.Plugins.Rtp.SrtpPrf {
|
||||
AES_CM
|
||||
}
|
||||
|
|
@ -53,6 +53,9 @@ public class Dino.Plugins.Rtp.Stream : Xmpp.Xep.JingleRtp.Stream {
|
|||
private Gst.Pad send_rtp_sink_pad;
|
||||
private Gst.Pad send_rtp_src_pad;
|
||||
|
||||
private SrtpSession? local_crypto_session;
|
||||
private SrtpSession? remote_crypto_session;
|
||||
|
||||
public Stream(Plugin plugin, Xmpp.Xep.Jingle.Content content) {
|
||||
base(content);
|
||||
this.plugin = plugin;
|
||||
|
|
@ -144,6 +147,20 @@ public class Dino.Plugins.Rtp.Stream : Xmpp.Xep.JingleRtp.Stream {
|
|||
plugin.unpause();
|
||||
}
|
||||
|
||||
private void prepare_local_crypto() {
|
||||
if (local_crypto != null && local_crypto_session == null) {
|
||||
local_crypto_session = new SrtpSession(
|
||||
local_crypto.crypto_suite == Xep.JingleRtp.Crypto.F8_128_HMAC_SHA1_80 ? SrtpEncryption.AES_F8 : SrtpEncryption.AES_CM,
|
||||
SrtpAuthentication.HMAC_SHA1,
|
||||
local_crypto.crypto_suite == Xep.JingleRtp.Crypto.AES_CM_128_HMAC_SHA1_32 ? 4 : 10,
|
||||
SrtpPrf.AES_CM,
|
||||
0
|
||||
);
|
||||
local_crypto_session.setkey(local_crypto.key, local_crypto.salt);
|
||||
debug("Setting up encryption with key params %s", local_crypto.key_params);
|
||||
}
|
||||
}
|
||||
|
||||
private Gst.FlowReturn on_new_sample(Gst.App.Sink sink) {
|
||||
if (sink == null) {
|
||||
debug("Sink is null");
|
||||
|
|
@ -153,9 +170,16 @@ public class Dino.Plugins.Rtp.Stream : Xmpp.Xep.JingleRtp.Stream {
|
|||
Gst.Buffer buffer = sample.get_buffer();
|
||||
uint8[] data;
|
||||
buffer.extract_dup(0, buffer.get_size(), out data);
|
||||
prepare_local_crypto();
|
||||
if (sink == send_rtp) {
|
||||
if (local_crypto_session != null) {
|
||||
data = local_crypto_session.encrypt_rtp(data, local_crypto.crypto_suite == Xep.JingleRtp.Crypto.AES_CM_128_HMAC_SHA1_32 ? 4 : 10);
|
||||
}
|
||||
on_send_rtp_data(new Bytes.take(data));
|
||||
} else if (sink == send_rtcp) {
|
||||
if (local_crypto_session != null) {
|
||||
data = local_crypto_session.encrypt_rtcp(data, local_crypto.crypto_suite == Xep.JingleRtp.Crypto.AES_CM_128_HMAC_SHA1_32 ? 4 : 10);
|
||||
}
|
||||
on_send_rtcp_data(new Bytes.take(data));
|
||||
} else {
|
||||
warning("unknown sample");
|
||||
|
|
@ -258,15 +282,47 @@ public class Dino.Plugins.Rtp.Stream : Xmpp.Xep.JingleRtp.Stream {
|
|||
recv_rtp_src_pad = null;
|
||||
}
|
||||
|
||||
private void prepare_remote_crypto() {
|
||||
if (remote_crypto != null && remote_crypto_session == null) {
|
||||
remote_crypto_session = new SrtpSession(
|
||||
remote_crypto.crypto_suite == Xep.JingleRtp.Crypto.F8_128_HMAC_SHA1_80 ? SrtpEncryption.AES_F8 : SrtpEncryption.AES_CM,
|
||||
SrtpAuthentication.HMAC_SHA1,
|
||||
remote_crypto.crypto_suite == Xep.JingleRtp.Crypto.AES_CM_128_HMAC_SHA1_32 ? 4 : 10,
|
||||
SrtpPrf.AES_CM,
|
||||
0
|
||||
);
|
||||
remote_crypto_session.setkey(remote_crypto.key, remote_crypto.salt);
|
||||
debug("Setting up decryption with key params %s", remote_crypto.key_params);
|
||||
}
|
||||
}
|
||||
|
||||
public override void on_recv_rtp_data(Bytes bytes) {
|
||||
prepare_remote_crypto();
|
||||
uint8[] data = bytes.get_data();
|
||||
if (remote_crypto_session != null) {
|
||||
try {
|
||||
data = remote_crypto_session.decrypt_rtp(data);
|
||||
} catch (Error e) {
|
||||
warning("%s (%d)", e.message, e.code);
|
||||
}
|
||||
}
|
||||
if (push_recv_data) {
|
||||
recv_rtp.push_buffer(new Gst.Buffer.wrapped_bytes(bytes));
|
||||
recv_rtp.push_buffer(new Gst.Buffer.wrapped((owned) data));
|
||||
}
|
||||
}
|
||||
|
||||
public override void on_recv_rtcp_data(Bytes bytes) {
|
||||
prepare_remote_crypto();
|
||||
uint8[] data = bytes.get_data();
|
||||
if (remote_crypto_session != null) {
|
||||
try {
|
||||
data = remote_crypto_session.decrypt_rtcp(data);
|
||||
} catch (Error e) {
|
||||
warning("%s (%d)", e.message, e.code);
|
||||
}
|
||||
}
|
||||
if (push_recv_data) {
|
||||
recv_rtcp.push_buffer(new Gst.Buffer.wrapped_bytes(bytes));
|
||||
recv_rtcp.push_buffer(new Gst.Buffer.wrapped((owned) data));
|
||||
}
|
||||
}
|
||||
|
||||
|
|
|
|||
|
|
@ -17,7 +17,9 @@ public class Xmpp.Xep.JingleRtp.Parameters : Jingle.ContentParameters, Object {
|
|||
public bool encryption_required { get; private set; default = false; }
|
||||
public PayloadType? agreed_payload_type { get; private set; }
|
||||
public Gee.List<PayloadType> payload_types = new ArrayList<PayloadType>(PayloadType.equals_func);
|
||||
public Gee.List<Crypto> cryptos = new ArrayList<Crypto>();
|
||||
public Gee.List<Crypto> remote_cryptos = new ArrayList<Crypto>();
|
||||
public Crypto? local_crypto = null;
|
||||
public Crypto? remote_crypto = null;
|
||||
|
||||
public weak Stream? stream { get; private set; }
|
||||
|
||||
|
|
@ -27,7 +29,7 @@ public class Xmpp.Xep.JingleRtp.Parameters : Jingle.ContentParameters, Object {
|
|||
string media, Gee.List<PayloadType> payload_types,
|
||||
string? ssrc = null, bool rtcp_mux = false,
|
||||
string? bandwidth = null, string? bandwidth_type = null,
|
||||
bool encryption_required = false, Gee.List<Crypto> cryptos = new ArrayList<Crypto>()
|
||||
bool encryption_required = false, Crypto? local_crypto = null
|
||||
) {
|
||||
this.parent = parent;
|
||||
this.media = media;
|
||||
|
|
@ -37,7 +39,7 @@ public class Xmpp.Xep.JingleRtp.Parameters : Jingle.ContentParameters, Object {
|
|||
this.bandwidth_type = bandwidth_type;
|
||||
this.encryption_required = encryption_required;
|
||||
this.payload_types = payload_types;
|
||||
this.cryptos = cryptos;
|
||||
this.local_crypto = local_crypto;
|
||||
}
|
||||
|
||||
public Parameters.from_node(Module parent, StanzaNode node) throws Jingle.IqError {
|
||||
|
|
@ -49,7 +51,7 @@ public class Xmpp.Xep.JingleRtp.Parameters : Jingle.ContentParameters, Object {
|
|||
if (encryption != null) {
|
||||
this.encryption_required = encryption.get_attribute_bool("required", this.encryption_required);
|
||||
foreach (StanzaNode crypto in encryption.get_subnodes("crypto")) {
|
||||
this.cryptos.add(Crypto.parse(crypto));
|
||||
this.remote_cryptos.add(Crypto.parse(crypto));
|
||||
}
|
||||
}
|
||||
foreach (StanzaNode payloadType in node.get_subnodes("payload-type")) {
|
||||
|
|
@ -64,6 +66,15 @@ public class Xmpp.Xep.JingleRtp.Parameters : Jingle.ContentParameters, Object {
|
|||
content.reject();
|
||||
return;
|
||||
}
|
||||
remote_crypto = parent.pick_remote_crypto(remote_cryptos);
|
||||
if (local_crypto == null && remote_crypto != null) {
|
||||
local_crypto = parent.pick_local_crypto(remote_crypto);
|
||||
}
|
||||
if ((local_crypto == null || remote_crypto == null) && encryption_required) {
|
||||
debug("no usable encryption, but encryption required");
|
||||
content.reject();
|
||||
return;
|
||||
}
|
||||
}
|
||||
|
||||
public void accept(XmppStream stream, Jingle.Session session, Jingle.Content content) {
|
||||
|
|
@ -97,6 +108,15 @@ public class Xmpp.Xep.JingleRtp.Parameters : Jingle.ContentParameters, Object {
|
|||
}
|
||||
});
|
||||
|
||||
if (remote_crypto == null || local_crypto == null) {
|
||||
if (encryption_required) {
|
||||
warning("Encryption required but not provided in both directions");
|
||||
return;
|
||||
}
|
||||
remote_crypto = null;
|
||||
local_crypto = null;
|
||||
}
|
||||
|
||||
this.stream = parent.create_stream(content);
|
||||
rtp_datagram.datagram_received.connect(this.stream.on_recv_rtp_data);
|
||||
rtcp_datagram.datagram_received.connect(this.stream.on_recv_rtcp_data);
|
||||
|
|
@ -118,6 +138,20 @@ public class Xmpp.Xep.JingleRtp.Parameters : Jingle.ContentParameters, Object {
|
|||
}
|
||||
agreed_payload_type = preferred_payload_type;
|
||||
|
||||
Gee.List<StanzaNode> crypto_nodes = description_node.get_deep_subnodes("encryption", "crypto");
|
||||
if (crypto_nodes.size == 0) {
|
||||
warning("Counterpart didn't include any cryptos");
|
||||
if (encryption_required) {
|
||||
return;
|
||||
}
|
||||
} else {
|
||||
Crypto preferred_crypto = Crypto.parse(crypto_nodes[0]);
|
||||
if (local_crypto.crypto_suite != preferred_crypto.crypto_suite) {
|
||||
warning("Counterpart's crypto suite doesn't match any of our sent ones");
|
||||
}
|
||||
remote_crypto = preferred_crypto;
|
||||
}
|
||||
|
||||
accept(stream, session, content);
|
||||
}
|
||||
|
||||
|
|
@ -137,6 +171,10 @@ public class Xmpp.Xep.JingleRtp.Parameters : Jingle.ContentParameters, Object {
|
|||
ret.put_node(payload_type.to_xml());
|
||||
}
|
||||
}
|
||||
if (local_crypto != null) {
|
||||
ret.put_node(new StanzaNode.build("encryption", NS_URI)
|
||||
.put_node(local_crypto.to_xml()));
|
||||
}
|
||||
return ret;
|
||||
}
|
||||
}
|
||||
|
|
@ -20,6 +20,9 @@ public abstract class Module : XmppStreamModule {
|
|||
|
||||
public abstract async Gee.List<PayloadType> get_supported_payloads(string media);
|
||||
public abstract async PayloadType? pick_payload_type(string media, Gee.List<PayloadType> payloads);
|
||||
public abstract Crypto? generate_local_crypto();
|
||||
public abstract Crypto? pick_remote_crypto(Gee.List<Crypto> cryptos);
|
||||
public abstract Crypto? pick_local_crypto(Crypto? remote);
|
||||
public abstract Stream create_stream(Jingle.Content content);
|
||||
public abstract void close_stream(Stream stream);
|
||||
|
||||
|
|
@ -36,6 +39,7 @@ public abstract class Module : XmppStreamModule {
|
|||
|
||||
// Create audio content
|
||||
Parameters audio_content_parameters = new Parameters(this, "audio", yield get_supported_payloads("audio"));
|
||||
audio_content_parameters.local_crypto = generate_local_crypto();
|
||||
Jingle.Transport? audio_transport = yield jingle_module.select_transport(stream, content_type.required_transport_type, content_type.required_components, receiver_full_jid, Set.empty());
|
||||
if (audio_transport == null) {
|
||||
throw new Jingle.Error.NO_SHARED_PROTOCOLS("No suitable audio transports");
|
||||
|
|
@ -52,6 +56,7 @@ public abstract class Module : XmppStreamModule {
|
|||
if (video) {
|
||||
// Create video content
|
||||
Parameters video_content_parameters = new Parameters(this, "video", yield get_supported_payloads("video"));
|
||||
video_content_parameters.local_crypto = generate_local_crypto();
|
||||
Jingle.Transport? video_transport = yield stream.get_module(Jingle.Module.IDENTITY).select_transport(stream, content_type.required_transport_type, content_type.required_components, receiver_full_jid, Set.empty());
|
||||
if (video_transport == null) {
|
||||
throw new Jingle.Error.NO_SHARED_PROTOCOLS("No suitable video transports");
|
||||
|
|
@ -92,6 +97,7 @@ public abstract class Module : XmppStreamModule {
|
|||
if (content == null) {
|
||||
// Content for video does not yet exist -> create it
|
||||
Parameters video_content_parameters = new Parameters(this, "video", yield get_supported_payloads("video"));
|
||||
video_content_parameters.local_crypto = generate_local_crypto();
|
||||
Jingle.Transport? video_transport = yield stream.get_module(Jingle.Module.IDENTITY).select_transport(stream, content_type.required_transport_type, content_type.required_components, receiver_full_jid, Set.empty());
|
||||
if (video_transport == null) {
|
||||
throw new Jingle.Error.NO_SHARED_PROTOCOLS("No suitable video transports");
|
||||
|
|
@ -148,26 +154,130 @@ public abstract class Module : XmppStreamModule {
|
|||
}
|
||||
|
||||
public class Crypto {
|
||||
public string cryptoSuite { get; private set; }
|
||||
public string keyParams { get; private set; }
|
||||
public string? sessionParams { get; private set; }
|
||||
public string? tag { get; private set; }
|
||||
public const string AES_CM_128_HMAC_SHA1_80 = "AES_CM_128_HMAC_SHA1_80";
|
||||
public const string AES_CM_128_HMAC_SHA1_32 = "AES_CM_128_HMAC_SHA1_32";
|
||||
public const string F8_128_HMAC_SHA1_80 = "F8_128_HMAC_SHA1_80";
|
||||
|
||||
public string crypto_suite { get; private set; }
|
||||
public string key_params { get; private set; }
|
||||
public string? session_params { get; private set; }
|
||||
public string tag { get; private set; }
|
||||
|
||||
public uint8[] key_and_salt { owned get {
|
||||
if (!key_params.has_prefix("inline:")) return null;
|
||||
int endIndex = key_params.index_of("|");
|
||||
if (endIndex < 0) endIndex = key_params.length;
|
||||
string sub = key_params.substring(7, endIndex - 7);
|
||||
return Base64.decode(sub);
|
||||
}}
|
||||
|
||||
public string? lifetime { owned get {
|
||||
if (!key_params.has_prefix("inline:")) return null;
|
||||
int firstIndex = key_params.index_of("|");
|
||||
if (firstIndex < 0) return null;
|
||||
int endIndex = key_params.index_of("|", firstIndex + 1);
|
||||
if (endIndex < 0) {
|
||||
if (key_params.index_of(":", firstIndex) > 0) return null; // Is MKI
|
||||
endIndex = key_params.length;
|
||||
}
|
||||
return key_params.substring(firstIndex + 1, endIndex);
|
||||
}}
|
||||
|
||||
public int mki { get {
|
||||
if (!key_params.has_prefix("inline:")) return -1;
|
||||
int firstIndex = key_params.index_of("|");
|
||||
if (firstIndex < 0) return -1;
|
||||
int splitIndex = key_params.index_of(":", firstIndex);
|
||||
if (splitIndex < 0) return -1;
|
||||
int secondIndex = key_params.index_of("|", firstIndex + 1);
|
||||
if (secondIndex < 0) {
|
||||
return int.parse(key_params.substring(firstIndex + 1, splitIndex));
|
||||
} else if (splitIndex > secondIndex) {
|
||||
return int.parse(key_params.substring(secondIndex + 1, splitIndex));
|
||||
}
|
||||
return -1;
|
||||
}}
|
||||
|
||||
public int mki_length { get {
|
||||
if (!key_params.has_prefix("inline:")) return -1;
|
||||
int firstIndex = key_params.index_of("|");
|
||||
if (firstIndex < 0) return -1;
|
||||
int splitIndex = key_params.index_of(":", firstIndex);
|
||||
if (splitIndex < 0) return -1;
|
||||
int secondIndex = key_params.index_of("|", firstIndex + 1);
|
||||
if (secondIndex < 0 || splitIndex > secondIndex) {
|
||||
return int.parse(key_params.substring(splitIndex + 1, key_params.length));
|
||||
}
|
||||
return -1;
|
||||
}}
|
||||
|
||||
public bool is_valid { get {
|
||||
switch(crypto_suite) {
|
||||
case AES_CM_128_HMAC_SHA1_80:
|
||||
case AES_CM_128_HMAC_SHA1_32:
|
||||
case F8_128_HMAC_SHA1_80:
|
||||
return key_and_salt.length == 30;
|
||||
}
|
||||
return false;
|
||||
}}
|
||||
|
||||
public uint8[] key { owned get {
|
||||
uint8[] key_and_salt = key_and_salt;
|
||||
switch(crypto_suite) {
|
||||
case AES_CM_128_HMAC_SHA1_80:
|
||||
case AES_CM_128_HMAC_SHA1_32:
|
||||
case F8_128_HMAC_SHA1_80:
|
||||
if (key_and_salt.length >= 16) return key_and_salt[0:16];
|
||||
break;
|
||||
}
|
||||
return null;
|
||||
}}
|
||||
|
||||
public uint8[] salt { owned get {
|
||||
uint8[] keyAndSalt = key_and_salt;
|
||||
switch(crypto_suite) {
|
||||
case AES_CM_128_HMAC_SHA1_80:
|
||||
case AES_CM_128_HMAC_SHA1_32:
|
||||
case F8_128_HMAC_SHA1_80:
|
||||
if (keyAndSalt.length >= 30) return keyAndSalt[16:30];
|
||||
break;
|
||||
}
|
||||
return null;
|
||||
}}
|
||||
|
||||
public static Crypto create(string crypto_suite, uint8[] key_and_salt, string? session_params = null, string tag = "1") {
|
||||
Crypto crypto = new Crypto();
|
||||
crypto.crypto_suite = crypto_suite;
|
||||
crypto.key_params = "inline:" + Base64.encode(key_and_salt);
|
||||
crypto.session_params = session_params;
|
||||
crypto.tag = tag;
|
||||
return crypto;
|
||||
}
|
||||
|
||||
public Crypto rekey(uint8[] key_and_salt) {
|
||||
Crypto crypto = new Crypto();
|
||||
crypto.crypto_suite = crypto_suite;
|
||||
crypto.key_params = "inline:" + Base64.encode(key_and_salt);
|
||||
crypto.session_params = session_params;
|
||||
crypto.tag = tag;
|
||||
return crypto;
|
||||
}
|
||||
|
||||
public static Crypto parse(StanzaNode node) {
|
||||
Crypto crypto = new Crypto();
|
||||
crypto.cryptoSuite = node.get_attribute("crypto-suite");
|
||||
crypto.keyParams = node.get_attribute("key-params");
|
||||
crypto.sessionParams = node.get_attribute("session-params");
|
||||
crypto.crypto_suite = node.get_attribute("crypto-suite");
|
||||
crypto.key_params = node.get_attribute("key-params");
|
||||
crypto.session_params = node.get_attribute("session-params");
|
||||
crypto.tag = node.get_attribute("tag");
|
||||
return crypto;
|
||||
}
|
||||
|
||||
public StanzaNode to_xml() {
|
||||
StanzaNode node = new StanzaNode.build("crypto", NS_URI)
|
||||
.put_attribute("crypto-suite", cryptoSuite)
|
||||
.put_attribute("key-params", keyParams);
|
||||
if (sessionParams != null) node.put_attribute("session-params", sessionParams);
|
||||
if (tag != null) node.put_attribute("tag", tag);
|
||||
.put_attribute("crypto-suite", crypto_suite)
|
||||
.put_attribute("key-params", key_params)
|
||||
.put_attribute("tag", tag);
|
||||
if (session_params != null) node.put_attribute("session-params", session_params);
|
||||
return node;
|
||||
}
|
||||
}
|
||||
|
|
|
|||
|
|
@ -17,6 +17,20 @@ public abstract class Xmpp.Xep.JingleRtp.Stream : Object {
|
|||
}
|
||||
return null;
|
||||
}}
|
||||
public JingleRtp.Crypto? local_crypto { get {
|
||||
var content_params = content.content_params;
|
||||
if (content_params is Parameters) {
|
||||
return ((Parameters)content_params).local_crypto;
|
||||
}
|
||||
return null;
|
||||
}}
|
||||
public JingleRtp.Crypto? remote_crypto { get {
|
||||
var content_params = content.content_params;
|
||||
if (content_params is Parameters) {
|
||||
return ((Parameters)content_params).remote_crypto;
|
||||
}
|
||||
return null;
|
||||
}}
|
||||
public bool sending { get {
|
||||
return content.session.senders_include_us(content.senders);
|
||||
}}
|
||||
|
|
|
|||
Loading…
Reference in a new issue