RTC: Support config the DTLS role and version

trunk/conf/full.conf

@@ -495,6 +495,12 @@ vhost rtc.vhost.srs.com {
         # If off, we will regenerate the sequence number for RTP packet.
         # default: off
         keep_sequence off;
+        # The role of dtls when peer is actpass: passive or active
+        # default: passive
+        dtls_role  passive;
+        # The version of dtls, support dtls1.0, dtls1.2, and auto
+        # default: auto
+        dtls_version auto;
     }
     # whether enable min delay mode for vhost.
     # default: on, for RTC.

trunk/src/app/srs_app_config.cpp

@@ -3935,7 +3935,7 @@ srs_error_t SrsConfig::check_normal_config()
                 for (int j = 0; j < (int)conf->directives.size(); j++) {
                     string m = conf->at(j)->name;
                     if (m != "enabled" && m != "bframe" && m != "aac" && m != "stun_timeout" && m != "stun_strict_check"
-                        && m != "keep_sequence") {
+                        && m != "keep_sequence" && m != "dtls_role" && m != "dtls_version") {
                         return srs_error_new(ERROR_SYSTEM_CONFIG_INVALID, "illegal vhost.rtc.%s of %s", m.c_str(), vhost->arg0().c_str());
                     }
                 }
@@ -5038,6 +5038,42 @@ bool SrsConfig::get_rtc_keep_sequence(string vhost)
     return SRS_CONF_PERFER_FALSE(conf->arg0());
 }
 
+std::string SrsConfig::get_rtc_dtls_role(string vhost)
+{
+    static std::string DEFAULT = "passive";
+
+    SrsConfDirective* conf = get_rtc(vhost);
+
+    if (!conf) {
+        return DEFAULT;
+    }
+
+    conf = conf->get("dtls_role");
+    if (!conf || conf->arg0().empty()) {
+        return DEFAULT;
+    }
+
+    return conf->arg0();
+}
+
+std::string SrsConfig::get_rtc_dtls_version(string vhost)
+{
+    static std::string DEFAULT = "auto";
+
+    SrsConfDirective* conf = get_rtc(vhost);
+
+    if (!conf) {
+        return DEFAULT;
+    }
+
+    conf = conf->get("dtls_version");
+    if (!conf || conf->arg0().empty()) {
+        return DEFAULT;
+    }
+
+    return conf->arg0();
+}
+
 bool SrsConfig::get_rtc_nack_enabled(string vhost)
 {
     static bool DEFAULT = true;
@@ -5078,6 +5114,7 @@ bool SrsConfig::get_rtc_twcc_enabled(string vhost)
     }
     return SRS_CONF_PERFER_TRUE(conf->arg0());
 }
+
 SrsConfDirective* SrsConfig::get_vhost(string vhost, bool try_default_vhost)
 {
     srs_assert(root);

trunk/src/app/srs_app_config.hpp

@@ -547,6 +547,8 @@ public:
     bool get_rtc_keep_sequence(std::string vhost);
     bool get_rtc_nack_enabled(std::string vhost);
     bool get_rtc_twcc_enabled(std::string vhost);
+    std::string get_rtc_dtls_role(std::string vhost);
+    std::string get_rtc_dtls_version(std::string vhost);
 
 // vhost specified section
 public:

trunk/src/app/srs_app_rtc_api.cpp

@@ -169,6 +169,11 @@ srs_error_t SrsGoApiRtcPlay::do_serve_http(ISrsHttpResponseWriter* w, ISrsHttpMe
     }
 
     SrsSdp local_sdp;
+
+    // Config for SDP and session.
+    local_sdp.session_config_.dtls_role = _srs_config->get_rtc_dtls_role(request.vhost);
+    local_sdp.session_config_.dtls_version = _srs_config->get_rtc_dtls_version(request.vhost);
+
     if ((err = exchange_sdp(&request, remote_sdp, local_sdp)) != srs_success) {
         return srs_error_wrap(err, "remote sdp have error or unsupport attributes");
     }
@@ -369,7 +374,7 @@ srs_error_t SrsGoApiRtcPlay::exchange_sdp(SrsRequest* req, const SrsSdp& remote_
         } else if (remote_media_desc.session_info_.setup_ == "passive") {
             local_media_desc.session_info_.setup_ = "active";
         } else if (remote_media_desc.session_info_.setup_ == "actpass") {
-            local_media_desc.session_info_.setup_ = "passive";
+            local_media_desc.session_info_.setup_ = local_sdp.session_config_.dtls_role;
         } else {
             // @see: https://tools.ietf.org/html/rfc4145#section-4.1
             // The default value of the setup attribute in an offer/answer exchange
@@ -527,6 +532,11 @@ srs_error_t SrsGoApiRtcPublish::do_serve_http(ISrsHttpResponseWriter* w, ISrsHtt
     }
 
     SrsSdp local_sdp;
+
+    // Config for SDP and session.
+    local_sdp.session_config_.dtls_role = _srs_config->get_rtc_dtls_role(request.vhost);
+    local_sdp.session_config_.dtls_version = _srs_config->get_rtc_dtls_version(request.vhost);
+
     if ((err = exchange_sdp(&request, remote_sdp, local_sdp)) != srs_success) {
         return srs_error_wrap(err, "remote sdp have error or unsupport attributes");
     }
@@ -746,7 +756,7 @@ srs_error_t SrsGoApiRtcPublish::exchange_sdp(SrsRequest* req, const SrsSdp& remo
         } else if (remote_media_desc.session_info_.setup_ == "passive") {
             local_media_desc.session_info_.setup_ = "active";
         } else if (remote_media_desc.session_info_.setup_ == "actpass") {
-            local_media_desc.session_info_.setup_ = "passive";
+            local_media_desc.session_info_.setup_ = local_sdp.session_config_.dtls_role;
         } else {
             // @see: https://tools.ietf.org/html/rfc4145#section-4.1
             // The default value of the setup attribute in an offer/answer exchange

trunk/src/app/srs_app_rtc_conn.cpp

@@ -130,14 +130,14 @@ SrsSecurityTransport::~SrsSecurityTransport()
     }
 }
 
-srs_error_t SrsSecurityTransport::initialize(SrsRequest* r)
+srs_error_t SrsSecurityTransport::initialize(SrsSessionConfig* cfg)
 {
-    return dtls_->initialize(r);
+    return dtls_->initialize(cfg->dtls_role, cfg->dtls_version);
 }
 
-srs_error_t SrsSecurityTransport::do_handshake()
+srs_error_t SrsSecurityTransport::start_active_handshake()
 {
-    return dtls_->do_handshake();
+    return dtls_->start_active_handshake();
 }
 
 srs_error_t SrsSecurityTransport::write_dtls_data(void* data, int size) 
@@ -1862,7 +1862,8 @@ srs_error_t SrsRtcSession::initialize(SrsRtcSource* source, SrsRequest* r, bool
     is_publisher_ = is_publisher;
     source_ = source;
 
-    if ((err = transport_->initialize(req)) != srs_success) {
+    SrsSessionConfig* cfg = &local_sdp.session_config_;
+    if ((err = transport_->initialize(cfg)) != srs_success) {
         return srs_error_wrap(err, "init");
     }
 
@@ -1872,7 +1873,8 @@ srs_error_t SrsRtcSession::initialize(SrsRtcSource* source, SrsRequest* r, bool
 
     blackhole = _srs_config->get_rtc_server_black_hole();
 
-    srs_trace("RTC init session, timeout=%dms, blackhole=%d", srsu2msi(sessionStunTimeout), blackhole);
+    srs_trace("RTC init session, DTLS(role=%s, version=%s), timeout=%dms, blackhole=%d",
+        cfg->dtls_role.c_str(), cfg->dtls_version.c_str(), srsu2msi(sessionStunTimeout), blackhole);
 
     if (blackhole) {
         string blackhole_ep = _srs_config->get_rtc_server_black_hole_addr();
@@ -2150,6 +2152,10 @@ srs_error_t SrsRtcSession::on_binding_request(SrsStunPacket* r)
 
         state_ = DOING_DTLS_HANDSHAKE;
         srs_trace("rtc session=%s, STUN done, waitting DTLS handshake.", id().c_str());
+
+        if((err = transport_->start_active_handshake()) != srs_success) {
+            return srs_error_wrap(err, "fail to dtls handshake");
+        }
     }
 
     if (blackhole && blackhole_addr && blackhole_stfd) {

trunk/src/app/srs_app_rtc_conn.hpp

@@ -117,9 +117,9 @@ public:
     SrsSecurityTransport(SrsRtcSession* s);
     virtual ~SrsSecurityTransport();
 
-    srs_error_t initialize(SrsRequest* r);
-
-    srs_error_t do_handshake();
+    srs_error_t initialize(SrsSessionConfig* cfg);
+    // When play role of dtls client, it send handshake. 
+    srs_error_t start_active_handshake();
     srs_error_t on_dtls(char* data, int nb_data);
 public:
     // Encrypt the input plaintext to output cipher with nb_cipher bytes.
@@ -377,6 +377,7 @@ public:
     void switch_to_context();
     std::string context_id();
 public:
+    // Before initialize, user must set the local SDP, which is used to inititlize DTLS.
     srs_error_t initialize(SrsRtcSource* source, SrsRequest* r, bool is_publisher, std::string username, std::string context_id);
     // The peer address may change, we can identify that by STUN messages.
     srs_error_t on_stun(SrsUdpMuxSocket* skt, SrsStunPacket* r);

trunk/src/app/srs_app_rtc_dtls.cpp

@@ -31,6 +31,7 @@ using namespace std;
 #include <srs_kernel_error.hpp>
 #include <srs_app_config.hpp>
 #include <srs_core_autofree.hpp>
+#include <srs_rtmp_stack.hpp>
 
 #include <srtp2/srtp.h>
 #include <openssl/ssl.h>
@@ -244,6 +245,9 @@ SrsDtls::SrsDtls(ISrsDtlsCallback* cb)
 {
     callback = cb;
     handshake_done = false;
+
+    role_ = SrsDtlsRoleServer;
+    version_ = SrsDtlsVersionAuto;
 }
 
 SrsDtls::~SrsDtls()
@@ -266,9 +270,14 @@ SSL_CTX* SrsDtls::build_dtls_ctx()
 #if OPENSSL_VERSION_NUMBER < 0x10002000L // v1.0.2
     dtls_ctx = SSL_CTX_new(DTLSv1_method());
 #else
-    dtls_ctx = SSL_CTX_new(DTLS_method());
-    //dtls_ctx = SSL_CTX_new(DTLSv1_method());
-    //dtls_ctx = SSL_CTX_new(DTLSv1_2_method());
+    if (version_ == SrsDtlsVersion1_0) {
+        dtls_ctx = SSL_CTX_new(DTLSv1_method());
+    } else if (version_ == SrsDtlsVersion1_2) {
+        dtls_ctx = SSL_CTX_new(DTLSv1_2_method());
+    } else {
+        // SrsDtlsVersionAuto, use version-flexible DTLS methods
+        dtls_ctx = SSL_CTX_new(DTLS_method());
+    }
 #endif
 
     if (_srs_rtc_dtls_certificate->is_ecdsa()) { // By ECDSA, https://stackoverflow.com/a/6006898
@@ -323,18 +332,38 @@ SSL_CTX* SrsDtls::build_dtls_ctx()
     return dtls_ctx;
 }
 
-srs_error_t SrsDtls::initialize(SrsRequest* r)
+srs_error_t SrsDtls::initialize(std::string role, std::string version)
 {
     srs_error_t err = srs_success;
 
+    role_ = SrsDtlsRoleServer;
+    if (role == "active") {
+        role_ = SrsDtlsRoleClient;
+    }
+
+    if (version == "dtls1.0") {
+        version_ = SrsDtlsVersion1_0;
+    } else if (version == "dtls1.2") {
+        version_ = SrsDtlsVersion1_2;
+    } else {
+        version_ = SrsDtlsVersionAuto;
+    }
+
     dtls_ctx = build_dtls_ctx();
+
     // TODO: FIXME: Leak for SSL_CTX* return by build_dtls_ctx.
     if ((dtls = SSL_new(dtls_ctx)) == NULL) {
         return srs_error_new(ERROR_OpenSslCreateSSL, "SSL_new dtls");
     }
 
-    // Dtls setup passive, as server role.
-    SSL_set_accept_state(dtls);
+    if (role == "active") {
+        // Dtls setup active, as client role.
+        SSL_set_connect_state(dtls);
+        SSL_set_max_send_fragment(dtls, 1500);
+    } else {
+        // Dtls setup passive, as server role.
+        SSL_set_accept_state(dtls);
+    }
 
     if ((bio_in = BIO_new(BIO_s_mem())) == NULL) {
         return srs_error_new(ERROR_OpenSslBIONew, "BIO_new in");
@@ -350,7 +379,7 @@ srs_error_t SrsDtls::initialize(SrsRequest* r)
     return err;
 }
 
-srs_error_t SrsDtls::handshake()
+srs_error_t SrsDtls::do_handshake()
 {
     srs_error_t err = srs_success;
 
@@ -406,7 +435,7 @@ srs_error_t SrsDtls::on_dtls(char* data, int nb_data)
     }
 
     if (!handshake_done) {
-        err = handshake();
+        err = do_handshake();
     } else {
         while (BIO_ctrl_pending(bio_in) > 0) {
             char dtls_read_buf[8092];
@@ -423,9 +452,13 @@ srs_error_t SrsDtls::on_dtls(char* data, int nb_data)
     return err;
 }
 
-srs_error_t SrsDtls::do_handshake() 
+srs_error_t SrsDtls::start_active_handshake()
 {
-    return handshake();
+    if (role_ == SrsDtlsRoleClient) {
+        return do_handshake();
+    }
+
+    return srs_success;
 }
 
 const int SRTP_MASTER_KEY_KEY_LEN = 16;
@@ -450,8 +483,13 @@ srs_error_t SrsDtls::get_srtp_key(std::string& recv_key, std::string& send_key)
     offset += SRTP_MASTER_KEY_SALT_LEN;
     std::string server_master_salt(reinterpret_cast<char*>(material + offset), SRTP_MASTER_KEY_SALT_LEN);
 
-    recv_key = client_master_key + client_master_salt;
-    send_key = server_master_key + server_master_salt;
+    if (role_ == SrsDtlsRoleClient) {
+        recv_key = server_master_key + server_master_salt;
+        send_key = client_master_key + client_master_salt;
+    } else {
+        recv_key = client_master_key + client_master_salt;
+        send_key = server_master_key + server_master_salt;
+    }
 
     return err;
 }

trunk/src/app/srs_app_rtc_dtls.hpp

@@ -62,6 +62,22 @@ public:
 // @global config object.
 extern SrsDtlsCertificate* _srs_rtc_dtls_certificate;
 
+// @remark: play the role of DTLS_CLIENT, will send handshake
+// packet first.
+enum SrsDtlsRole {
+    SrsDtlsRoleClient,
+    SrsDtlsRoleServer
+};
+
+// @remark: DTLS_10 will all be ignored, and only DTLS1_2 will be accepted,
+// DTLS_10 Support will be completely removed in M84 or later.
+// TODO(https://bugs.webrtc.org/10261).
+enum SrsDtlsVersion {
+    SrsDtlsVersionAuto = -1,
+    SrsDtlsVersion1_0,
+    SrsDtlsVersion1_2
+};
+
 class ISrsDtlsCallback
 {
 public:
@@ -85,19 +101,26 @@ private:
     BIO* bio_out;
 
     ISrsDtlsCallback* callback;
-
     bool handshake_done;
+
+    // @remark: dtls_role_ default value is DTLS_SERVER.
+    SrsDtlsRole role_;
+    // @remark: dtls_version_ default value is SrsDtlsVersionAuto.
+    SrsDtlsVersion version_;
 public:
     SrsDtls(ISrsDtlsCallback* callback);
     virtual ~SrsDtls();
 public:
-    srs_error_t initialize(SrsRequest* r);  
-    srs_error_t do_handshake();
+    srs_error_t initialize(std::string role, std::string version);
+    // As DTLS client, start handshake actively, send the ClientHello packet.
+    srs_error_t start_active_handshake();
+    // When got DTLS packet, may handshake packets or application data.
+    // @remark When we are passive(DTLS server), we start handshake when got DTLS packet.
     srs_error_t on_dtls(char* data, int nb_data);
     srs_error_t get_srtp_key(std::string& recv_key, std::string& send_key);
 private:
     SSL_CTX* build_dtls_ctx();
-    srs_error_t handshake();
+    srs_error_t do_handshake();
 };
 
 class SrsSRTP

trunk/src/app/srs_app_rtc_sdp.hpp

@@ -34,6 +34,13 @@
 #include <map>
 const std::string kTWCCExt = "http://www.ietf.org/id/draft-holmer-rmcat-transport-wide-cc-extensions-01";
 
+struct SrsSessionConfig
+{
+public:
+    std::string dtls_role;
+    std::string dtls_version;
+};
+
 class SrsSessionInfo
 {
 public:
@@ -212,6 +219,7 @@ public:
     int64_t end_time_;
 
     SrsSessionInfo session_info_;
+    SrsSessionConfig session_config_;
 
     std::vector<std::string> groups_;
     std::string group_policy_;

trunk/src/app/srs_app_rtc_server.cpp

@@ -323,16 +323,6 @@ srs_error_t SrsRtcServer::create_session(
         }
     }
 
-    std::string cid = _srs_context->get_id();
-    SrsRtcSession* session = new SrsRtcSession(this);
-    if ((err = session->initialize(source, req, publish, username, cid)) != srs_success) {
-        srs_freep(session);
-        return srs_error_wrap(err, "init");
-    }
-
-    map_username_session.insert(make_pair(username, session));
-    *psession = session;
-
     local_sdp.set_ice_ufrag(local_ufrag);
     local_sdp.set_ice_pwd(local_pwd);
     local_sdp.set_fingerprint_algo("sha-256");
@@ -348,10 +338,22 @@ srs_error_t SrsRtcServer::create_session(
         }
     }
 
+    SrsRtcSession* session = new SrsRtcSession(this);
     session->set_remote_sdp(remote_sdp);
+    // We must setup the local SDP, then initialize the session object.
     session->set_local_sdp(local_sdp);
     session->set_state(WAITING_STUN);
 
+    std::string cid = _srs_context->get_id();
+    // Before session initialize, we must setup the local SDP.
+    if ((err = session->initialize(source, req, publish, username, cid)) != srs_success) {
+        srs_freep(session);
+        return srs_error_wrap(err, "init");
+    }
+
+    map_username_session.insert(make_pair(username, session));
+    *psession = session;
+
     return err;
 }