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/*
* TLS Channel
* (C) 2011,2012 Jack Lloyd
*
* Released under the terms of the Botan license
*/
#ifndef BOTAN_TLS_CHANNEL_H__
#define BOTAN_TLS_CHANNEL_H__
#include <botan/tls_policy.h>
#include <botan/tls_session.h>
#include <botan/tls_alert.h>
#include <botan/tls_session_manager.h>
#include <botan/x509cert.h>
#include <vector>
#include <string>
#include <memory>
#include <map>
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:
/**
* 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)
*/
virtual size_t received_data(const byte buf[], size_t buf_size);
/**
* Inject plaintext intended for counterparty
*/
void send(const byte buf[], size_t buf_size);
/**
* Inject plaintext intended for counterparty
*/
void send(const std::string& string);
/**
* Send a close notification alert
*/
void close() { send_alert(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;
/**
* 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 peer supports heartbeat messages
*/
bool peer_supports_heartbeats() const;
/**
* @return true iff we are allowed to send heartbeat messages
*/
bool heartbeat_sending_allowed() const;
/**
* @return true iff the counterparty supports the secure
* renegotiation extensions.
*/
bool secure_renegotiation_supported() 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
*/
void heartbeat(const byte payload[], size_t payload_size);
/**
* Attempt to send a heartbeat message (if negotiated with counterparty)
*/
void heartbeat() { heartbeat(nullptr, 0); }
/**
* @return certificate chain of the peer (may be empty)
*/
std::vector<X509_Certificate> 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;
Channel(std::function<void (const byte[], size_t)> socket_output_fn,
std::function<void (const byte[], size_t, Alert)> proc_fn,
std::function<bool (const Session&)> handshake_complete,
Session_Manager& session_manager,
RandomNumberGenerator& rng);
Channel(const Channel&) = delete;
Channel& operator=(const Channel&) = delete;
virtual ~Channel();
protected:
virtual void process_handshake_msg(const Handshake_State* active_state,
Handshake_State& pending_state,
Handshake_Type type,
const std::vector<byte>& contents) = 0;
virtual void initiate_handshake(Handshake_State& state,
bool force_full_renegotiation) = 0;
virtual std::vector<X509_Certificate>
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);
/**
* 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);
void activate_session();
void set_maximum_fragment_size(size_t maximum);
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<byte> secure_renegotiation_data_for_client_hello() const;
std::vector<byte> 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_fn(session); }
private:
void send_record(byte record_type, const std::vector<byte>& record);
void send_record_array(byte type, const byte input[], size_t length);
void write_record(Connection_Cipher_State* cipher_state,
byte type, const byte input[], size_t length);
Connection_Sequence_Numbers& sequence_numbers() const;
std::shared_ptr<Connection_Cipher_State> read_cipher_state_epoch(u16bit epoch) const;
std::shared_ptr<Connection_Cipher_State> write_cipher_state_epoch(u16bit epoch) const;
std::shared_ptr<Connection_Cipher_State> read_cipher_state_current() const;
std::shared_ptr<Connection_Cipher_State> write_cipher_state_current() const;
u16bit get_last_valid_epoch() const;
const Handshake_State* active_state() const { return m_active_state.get(); }
const Handshake_State* pending_state() const { return m_pending_state.get(); }
/* callbacks */
std::function<bool (const Session&)> m_handshake_fn;
std::function<void (const byte[], size_t, Alert)> m_proc_fn;
std::function<void (const byte[], size_t)> m_output_fn;
/* external state */
RandomNumberGenerator& m_rng;
Session_Manager& m_session_manager;
/* sequence number state */
std::unique_ptr<Connection_Sequence_Numbers> m_sequence_numbers;
/* I/O buffers */
std::vector<byte> m_writebuf;
std::vector<byte> m_readbuf;
/* cipher states for each epoch - epoch 0 is plaintext, thus null cipher state */
std::map<u16bit, std::shared_ptr<Connection_Cipher_State>> m_write_cipher_states =
{ { 0, nullptr } };
std::map<u16bit, std::shared_ptr<Connection_Cipher_State>> m_read_cipher_states =
{ { 0, nullptr } };
/* pending and active connection states */
std::unique_ptr<Handshake_State> m_active_state;
std::unique_ptr<Handshake_State> m_pending_state;
/* misc, should be removed? */
size_t m_max_fragment = MAX_PLAINTEXT_SIZE;
bool m_connection_closed = false;
};
}
}
#endif
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