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/*
* TLS Handshake Serialization
* (C) 2012,2014 Jack Lloyd
*
* Botan is released under the Simplified BSD License (see license.txt)
*/
#ifndef BOTAN_TLS_HANDSHAKE_IO_H_
#define BOTAN_TLS_HANDSHAKE_IO_H_
#include <botan/tls_magic.h>
#include <botan/tls_version.h>
#include <botan/internal/tls_channel_impl.h>
#include <deque>
#include <functional>
#include <map>
#include <set>
#include <utility>
#include <vector>
namespace Botan::TLS {
class Handshake_Message;
/**
* Handshake IO Interface
*
* This interface abstracts over stream and datagram processing of handshake
* messages. It receives individual records from the channel via `add_record` and provides a
* sending interface via a callback function provided by the channel.
*
* Handshake message headers are parsed and removed in `get_next_record`. The
* result is provided back to the channel via
* `Handshake_State::get_next_handshake_msg`.
*
* `send` is used by individual handshake message implementations, which send
* themselves, as well as both client and server to dispatch CCS messaged (and
* Hello_Verify_Request in the server case). Before calling the `writer_fn`,
* `format` is called to add the handshake message header (except for CCS).
*
* The buffer returned by `send` is used to update the transcript record hash
* (where desired).
*/
class Handshake_IO {
public:
virtual Protocol_Version initial_record_version() const = 0;
virtual std::vector<uint8_t> send(const Handshake_Message& msg) = 0;
virtual std::vector<uint8_t> send_under_epoch(const Handshake_Message& msg, uint16_t epoch) = 0;
virtual bool timeout_check() = 0;
virtual bool have_more_data() const = 0;
virtual std::vector<uint8_t> format(const std::vector<uint8_t>& handshake_msg,
Handshake_Type handshake_type) const = 0;
virtual void add_record(const uint8_t record[],
size_t record_len,
Record_Type type,
uint64_t sequence_number) = 0;
/**
* Returns (HANDSHAKE_NONE, std::vector<>()) if no message currently available
*/
virtual std::pair<Handshake_Type, std::vector<uint8_t>> get_next_record(bool expecting_ccs) = 0;
Handshake_IO() = default;
Handshake_IO(const Handshake_IO&) = delete;
Handshake_IO& operator=(const Handshake_IO&) = delete;
virtual ~Handshake_IO() = default;
};
/**
* Handshake IO for stream-based handshakes
*/
class Stream_Handshake_IO final : public Handshake_IO {
public:
typedef std::function<void(Record_Type, const std::vector<uint8_t>&)> writer_fn;
explicit Stream_Handshake_IO(writer_fn writer) : m_send_hs(writer) {}
Protocol_Version initial_record_version() const override;
bool timeout_check() override { return false; }
bool have_more_data() const override { return m_queue.empty() == false; }
std::vector<uint8_t> send(const Handshake_Message& msg) override;
std::vector<uint8_t> send_under_epoch(const Handshake_Message& msg, uint16_t epoch) override;
std::vector<uint8_t> format(const std::vector<uint8_t>& handshake_msg,
Handshake_Type handshake_type) const override;
void add_record(const uint8_t record[], size_t record_len, Record_Type type, uint64_t sequence_number) override;
std::pair<Handshake_Type, std::vector<uint8_t>> get_next_record(bool expecting_ccs) override;
private:
std::deque<uint8_t> m_queue;
writer_fn m_send_hs;
};
/**
* Handshake IO for datagram-based handshakes
*/
class Datagram_Handshake_IO final : public Handshake_IO {
public:
typedef std::function<void(uint16_t, Record_Type, const std::vector<uint8_t>&)> writer_fn;
Datagram_Handshake_IO(writer_fn writer,
class Connection_Sequence_Numbers& seq,
uint16_t mtu,
uint64_t initial_timeout_ms,
uint64_t max_timeout_ms) :
m_seqs(seq),
m_flights(1),
m_initial_timeout(initial_timeout_ms),
m_max_timeout(max_timeout_ms),
m_send_hs(writer),
m_mtu(mtu) {}
Protocol_Version initial_record_version() const override;
bool timeout_check() override;
bool have_more_data() const override;
std::vector<uint8_t> send(const Handshake_Message& msg) override;
std::vector<uint8_t> send_under_epoch(const Handshake_Message& msg, uint16_t epoch) override;
std::vector<uint8_t> format(const std::vector<uint8_t>& handshake_msg,
Handshake_Type handshake_type) const override;
void add_record(const uint8_t record[], size_t record_len, Record_Type type, uint64_t sequence_number) override;
std::pair<Handshake_Type, std::vector<uint8_t>> get_next_record(bool expecting_ccs) override;
private:
void retransmit_flight(size_t flight);
void retransmit_last_flight();
std::vector<uint8_t> format_fragment(const uint8_t fragment[],
size_t fragment_len,
uint16_t frag_offset,
uint16_t msg_len,
Handshake_Type type,
uint16_t msg_sequence) const;
std::vector<uint8_t> format_w_seq(const std::vector<uint8_t>& handshake_msg,
Handshake_Type handshake_type,
uint16_t msg_sequence) const;
std::vector<uint8_t> send_message(uint16_t msg_seq,
uint16_t epoch,
Handshake_Type msg_type,
const std::vector<uint8_t>& msg);
class Handshake_Reassembly final {
public:
void add_fragment(const uint8_t fragment[],
size_t fragment_length,
size_t fragment_offset,
uint16_t epoch,
Handshake_Type msg_type,
size_t msg_length);
bool complete() const;
uint16_t epoch() const { return m_epoch; }
std::pair<Handshake_Type, std::vector<uint8_t>> message() const;
private:
Handshake_Type m_msg_type = Handshake_Type::None;
size_t m_msg_length = 0;
uint16_t m_epoch = 0;
// vector<bool> m_seen;
// vector<uint8_t> m_fragments
std::map<size_t, uint8_t> m_fragments;
std::vector<uint8_t> m_message;
};
struct Message_Info final {
Message_Info(uint16_t e, Handshake_Type mt, const std::vector<uint8_t>& msg) :
epoch(e), msg_type(mt), msg_bits(msg) {}
Message_Info() : epoch(0xFFFF), msg_type(Handshake_Type::None) {}
uint16_t epoch;
Handshake_Type msg_type;
std::vector<uint8_t> msg_bits;
};
class Connection_Sequence_Numbers& m_seqs;
std::map<uint16_t, Handshake_Reassembly> m_messages;
std::set<uint16_t> m_ccs_epochs;
std::vector<std::vector<uint16_t>> m_flights;
std::map<uint16_t, Message_Info> m_flight_data;
uint64_t m_initial_timeout = 0;
uint64_t m_max_timeout = 0;
uint64_t m_last_write = 0;
uint64_t m_next_timeout = 0;
uint16_t m_in_message_seq = 0;
uint16_t m_out_message_seq = 0;
writer_fn m_send_hs;
uint16_t m_mtu;
};
} // namespace Botan::TLS
#endif