/* * TLS Channel * (C) 2011,2012,2014,2015 Jack Lloyd * * Botan is released under the Simplified BSD License (see license.txt) */ #ifndef BOTAN_TLS_CHANNEL_H__ #define BOTAN_TLS_CHANNEL_H__ #include #include #include #include #include #include #include #include namespace Botan { namespace TLS { class Connection_Cipher_State; class Connection_Sequence_Numbers; class Handshake_State; /** * Generic interface for TLS endpoint */ class BOTAN_DLL Channel { public: typedef std::function output_fn; typedef std::function data_cb; typedef std::function alert_cb; typedef std::function handshake_cb; Channel(output_fn out, data_cb app_data_cb, alert_cb alert_cb, handshake_cb hs_cb, Session_Manager& session_manager, RandomNumberGenerator& rng, bool is_datagram, size_t reserved_io_buffer_size); Channel(const Channel&) = delete; Channel& operator=(const Channel&) = delete; virtual ~Channel(); /** * Inject TLS traffic received from counterparty * @return a hint as the how many more bytes we need to process the * current record (this may be 0 if on a record boundary) */ size_t received_data(const byte buf[], size_t buf_size); /** * Inject TLS traffic received from counterparty * @return a hint as the how many more bytes we need to process the * current record (this may be 0 if on a record boundary) */ size_t received_data(const std::vector& buf); /** * Inject plaintext intended for counterparty * Throws an exception if is_active() is false */ void send(const byte buf[], size_t buf_size); /** * Inject plaintext intended for counterparty * Throws an exception if is_active() is false */ void send(const std::string& val); /** * Inject plaintext intended for counterparty * Throws an exception if is_active() is false */ template void send(const std::vector& val) { send(val.data(), val.size()); } /** * Send a TLS alert message. If the alert is fatal, the internal * state (keys, etc) will be reset. * @param alert the Alert to send */ void send_alert(const Alert& alert); /** * Send a warning alert */ void send_warning_alert(Alert::Type type) { send_alert(Alert(type, false)); } /** * Send a fatal alert */ void send_fatal_alert(Alert::Type type) { send_alert(Alert(type, true)); } /** * Send a close notification alert */ void close() { send_warning_alert(Alert::CLOSE_NOTIFY); } /** * @return true iff the connection is active for sending application data */ bool is_active() const; /** * @return true iff the connection has been definitely closed */ bool is_closed() const; /** * @return certificate chain of the peer (may be empty) */ std::vector peer_cert_chain() const; /** * Key material export (RFC 5705) * @param label a disambiguating label string * @param context a per-association context value * @param length the length of the desired key in bytes * @return key of length bytes */ SymmetricKey key_material_export(const std::string& label, const std::string& context, size_t length) const; /** * Attempt to renegotiate the session * @param force_full_renegotiation if true, require a full renegotiation, * otherwise allow session resumption */ void renegotiate(bool force_full_renegotiation = false); /** * @return true iff the counterparty supports the secure * renegotiation extensions. */ bool secure_renegotiation_supported() const; /** * Perform a handshake timeout check. This does nothing unless * this is a DTLS channel with a pending handshake state, in * which case we check for timeout and potentially retransmit * handshake packets. */ bool timeout_check(); /** * @return true iff the peer supports heartbeat messages */ bool peer_supports_heartbeats() const; /** * @return true iff we are allowed to send heartbeat messages */ bool heartbeat_sending_allowed() const; /** * Attempt to send a heartbeat message (if negotiated with counterparty) * @param payload will be echoed back * @param payload_size size of payload in bytes * @param pad_bytes include 16 + pad_bytes extra bytes in the message (not echoed) */ void heartbeat(const byte payload[], size_t payload_size, size_t pad_bytes = 0); /** * Attempt to send a heartbeat message (if negotiated with counterparty) */ void heartbeat() { heartbeat(nullptr, 0); } protected: virtual void process_handshake_msg(const Handshake_State* active_state, Handshake_State& pending_state, Handshake_Type type, const std::vector& contents) = 0; virtual void initiate_handshake(Handshake_State& state, bool force_full_renegotiation) = 0; virtual std::vector get_peer_cert_chain(const Handshake_State& state) const = 0; virtual Handshake_State* new_handshake_state(class Handshake_IO* io) = 0; Handshake_State& create_handshake_state(Protocol_Version version); void activate_session(); void change_cipher_spec_reader(Connection_Side side); void change_cipher_spec_writer(Connection_Side side); /* secure renegotiation handling */ void secure_renegotiation_check(const class Client_Hello* client_hello); void secure_renegotiation_check(const class Server_Hello* server_hello); std::vector secure_renegotiation_data_for_client_hello() const; std::vector secure_renegotiation_data_for_server_hello() const; RandomNumberGenerator& rng() { return m_rng; } Session_Manager& session_manager() { return m_session_manager; } bool save_session(const Session& session) const { return m_handshake_cb(session); } private: size_t maximum_fragment_size() const; void send_record(byte record_type, const std::vector& record); void send_record_under_epoch(u16bit epoch, byte record_type, const std::vector& record); void send_record_array(u16bit epoch, byte record_type, const byte input[], size_t length); void write_record(Connection_Cipher_State* cipher_state, u16bit epoch, byte type, const byte input[], size_t length); Connection_Sequence_Numbers& sequence_numbers() const; std::shared_ptr read_cipher_state_epoch(u16bit epoch) const; std::shared_ptr write_cipher_state_epoch(u16bit epoch) const; void reset_state(); const Handshake_State* active_state() const { return m_active_state.get(); } const Handshake_State* pending_state() const { return m_pending_state.get(); } bool m_is_datagram; /* callbacks */ handshake_cb m_handshake_cb; data_cb m_data_cb; alert_cb m_alert_cb; output_fn m_output_fn; /* external state */ RandomNumberGenerator& m_rng; Session_Manager& m_session_manager; /* sequence number state */ std::unique_ptr m_sequence_numbers; /* pending and active connection states */ std::unique_ptr m_active_state; std::unique_ptr m_pending_state; /* cipher states for each epoch */ std::map> m_write_cipher_states; std::map> m_read_cipher_states; /* I/O buffers */ secure_vector m_writebuf; secure_vector m_readbuf; }; } } #endif