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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>
namespace Botan {
namespace TLS {
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 m_active_state && !is_closed(); }
/**
* @return true iff the connection has been definitely closed
*/
bool is_closed() const { return m_connection_closed; }
/**
* 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);
/**
* 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() = 0;
Handshake_State& create_handshake_state();
/**
* 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_protocol_version(Protocol_Version version);
Protocol_Version current_protocol_version() const
{ return m_current_version; }
void set_maximum_fragment_size(size_t maximum);
void change_cipher_spec_reader(Connection_Side side);
void change_cipher_spec_writer(Connection_Side side);
void send_record(byte record_type, const std::vector<byte>& record);
/* 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;
bool secure_renegotiation_supported() const;
/* state accesssible by subclasses */
std::function<bool (const Session&)> m_handshake_fn;
RandomNumberGenerator& m_rng;
Session_Manager& m_session_manager;
private:
void send_record(byte type, const byte input[], size_t length);
void write_record(byte type, const byte input[], size_t length);
bool peer_supports_heartbeats() const;
bool heartbeat_sending_allowed() const;
/* callbacks */
std::function<void (const byte[], size_t, Alert)> m_proc_fn;
std::function<void (const byte[], size_t)> m_output_fn;
/* writing cipher state */
std::vector<byte> m_writebuf;
std::unique_ptr<class Connection_Cipher_State> m_write_cipherstate;
u64bit m_write_seq_no = 0;
/* reading cipher state */
std::vector<byte> m_readbuf;
size_t m_readbuf_pos = 0;
std::unique_ptr<class Connection_Cipher_State> m_read_cipherstate;
u64bit m_read_seq_no = 0;
/* connection parameters */
std::unique_ptr<Handshake_State> m_active_state;
std::unique_ptr<Handshake_State> m_pending_state;
Protocol_Version m_current_version;
size_t m_max_fragment = MAX_PLAINTEXT_SIZE;
bool m_secure_renegotiation = false;
bool m_connection_closed = false;
};
}
}
#endif
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