/*

* TLS Handshake State

* (C) 2004-2006,2011,2012 Jack Lloyd

*     2017 Harry Reimann, Rohde & Schwarz Cybersecurity

*

* Botan is released under the Simplified BSD License (see license.txt)

*/

#ifndef BOTAN_TLS_HANDSHAKE_STATE_H_

#define BOTAN_TLS_HANDSHAKE_STATE_H_

#include <botan/internal/tls_handshake_hash.h>

#include <botan/internal/tls_handshake_io.h>

#include <botan/internal/tls_handshake_transitions.h>

#include <botan/internal/tls_session_key.h>

#include <botan/tls_ciphersuite.h>

#include <botan/tls_exceptn.h>

#include <botan/tls_handshake_msg.h>

#include <botan/tls_callbacks.h>

#include <botan/pk_keys.h>

#include <botan/pubkey.h>

#include <functional>

#include <optional>

namespace Botan {

class KDF;

namespace TLS {

class Callbacks;

class Policy;

class Signature_Scheme;

class Hello_Verify_Request;

class Client_Hello_12;

class Server_Hello_12;

class Certificate_12;

class Certificate_Status;

class Server_Key_Exchange;

class Certificate_Request_12;

class Server_Hello_Done;

class Client_Key_Exchange;

class Certificate_Verify_12;

class New_Session_Ticket_12;

class Finished_12;

/**

* SSL/TLS Handshake State

*

* This is a data holder object for all state aggregated during the handshake,

* both on client and server side and across protocol versions.

* It does not implement any logic and offers no guarantees regarding state

* consistency and legal TLS state transitions.

*

* TODO: currently it implements some logic for TLS 1.2, which should be removed

* TODO: investigate moving the handshake_io to the channel

*/

class Handshake_State

   {

   public:

      Handshake_State(std::unique_ptr<Handshake_IO> io, Callbacks& callbacks);

      virtual ~Handshake_State();

      Handshake_State(const Handshake_State&) = delete;

      Handshake_State& operator=(const Handshake_State&) = delete;

      Handshake_IO& handshake_io() { return *m_handshake_io; }

      /**

      * Return true iff we have received a particular message already

      * @param msg_type the message type

      */

      bool received_handshake_msg(Handshake_Type msg_type) const;

      /**

      * Confirm that we were expecting this message type

      * @param msg_type the message type

      */

      void confirm_transition_to(Handshake_Type msg_type);

      /**

      * Record that we are expecting a particular message type next

      * @param msg_type the message type

      */

      void set_expected_next(Handshake_Type msg_type);

      std::pair<Handshake_Type, std::vector<uint8_t>>

         get_next_handshake_msg();

      std::vector<uint8_t> session_ticket() const;

      std::pair<std::string, Signature_Format>

         parse_sig_format(const Public_Key& key,

                          Signature_Scheme scheme,

                          const std::vector<Signature_Scheme>& offered_schemes,

                          bool for_client_auth,

                          const Policy& policy) const;

      std::pair<std::string, Signature_Format>

         choose_sig_format(const Private_Key& key,

                           Signature_Scheme& scheme,

                           bool for_client_auth,

                           const Policy& policy) const;

      std::unique_ptr<KDF> protocol_specific_prf() const;

      Protocol_Version version() const { return m_version; }

      void set_version(const Protocol_Version& version);

      void hello_verify_request(const Hello_Verify_Request& hello_verify);

      // TODO: take unique_ptr instead of raw pointers for all of these, as

      // we're taking the ownership

      void client_hello(Client_Hello_12* client_hello);

      void server_hello(Server_Hello_12* server_hello);

      void server_cert_status(Certificate_Status* server_cert_status);

      void server_kex(Server_Key_Exchange* server_kex);

      void cert_req(Certificate_Request_12* cert_req);

      void server_hello_done(Server_Hello_Done* server_hello_done);

      void client_kex(Client_Key_Exchange* client_kex);

      void client_certs(Certificate_12* client_certs);

      void server_certs(Certificate_12* server_certs);

      void client_verify(Certificate_Verify_12* client_verify);

      void server_verify(Certificate_Verify_12* server_verify);

      void server_finished(Finished_12* server_finished);

      void client_finished(Finished_12* client_finished);

      void new_session_ticket(New_Session_Ticket_12* new_session_ticket);

      const Client_Hello_12* client_hello() const

         { return m_client_hello.get(); }

      const Server_Hello_12* server_hello() const

         { return m_server_hello.get(); }

      const Certificate_12* server_certs() const

         { return m_server_certs.get(); }

      const Server_Key_Exchange* server_kex() const

         { return m_server_kex.get(); }

      const Certificate_Request_12* cert_req() const

         { return m_cert_req.get(); }

      const Server_Hello_Done* server_hello_done() const

         { return m_server_hello_done.get(); }

      const Certificate_12* client_certs() const

         { return m_client_certs.get(); }

      const Client_Key_Exchange* client_kex() const

         { return m_client_kex.get(); }

      const Certificate_Verify_12* client_verify() const

         { return m_client_verify.get(); }

      const Certificate_Verify_12* server_verify() const

         { return m_server_verify.get(); }

      const Certificate_Status* server_cert_status() const

         { return m_server_cert_status.get(); }

      const New_Session_Ticket_12* new_session_ticket() const

         { return m_new_session_ticket.get(); }

      const Finished_12* server_finished() const

         { return m_server_finished.get(); }

      const Finished_12* client_finished() const

         { return m_client_finished.get(); }

      const Ciphersuite& ciphersuite() const;

      const Session_Keys& session_keys() const { return m_session_keys; }

      Callbacks& callbacks() const { return m_callbacks; }

      void compute_session_keys();

      void compute_session_keys(const secure_vector<uint8_t>& resume_master_secret);

      Handshake_Hash& hash() { return m_handshake_hash; }

      const Handshake_Hash& hash() const { return m_handshake_hash; }

      void note_message(const Handshake_Message& msg);

   private:

      Callbacks& m_callbacks;

      std::unique_ptr<Handshake_IO> m_handshake_io;

      Handshake_Transitions m_transitions;

      Protocol_Version m_version;

      std::optional<Ciphersuite> m_ciphersuite;

      Session_Keys m_session_keys;

      Handshake_Hash m_handshake_hash;

      std::unique_ptr<Client_Hello_12> m_client_hello;

      std::unique_ptr<Server_Hello_12> m_server_hello;

      std::unique_ptr<Certificate_12> m_server_certs;

      std::unique_ptr<Certificate_Status> m_server_cert_status;

      std::unique_ptr<Server_Key_Exchange> m_server_kex;

      std::unique_ptr<Certificate_Request_12> m_cert_req;

      std::unique_ptr<Server_Hello_Done> m_server_hello_done;

      std::unique_ptr<Certificate_12> m_client_certs;

      std::unique_ptr<Client_Key_Exchange> m_client_kex;

      std::unique_ptr<Certificate_Verify_12> m_client_verify;

      std::unique_ptr<Certificate_Verify_12> m_server_verify;

      std::unique_ptr<New_Session_Ticket_12> m_new_session_ticket;

      std::unique_ptr<Finished_12> m_server_finished;

      std::unique_ptr<Finished_12> m_client_finished;

   };

}

}

#endif