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/*
* TLS Client/Server Hello Internal Data Containers
* (C) 2004-2026 Jack Lloyd
* 2021 Elektrobit Automotive GmbH
* 2022 René Meusel, Hannes Rantzsch - neXenio GmbH
* 2026 René Meusel - Rohde & Schwarz Cybersecurity GmbH
*
* Botan is released under the Simplified BSD License (see license.txt)
*/
#ifndef BOTAN_TLS_MESSAGES_INTERNAL_H_
#define BOTAN_TLS_MESSAGES_INTERNAL_H_
#include <botan/tls_extensions.h>
#include <botan/tls_session.h>
#include <botan/tls_version.h>
#include <vector>
namespace Botan {
class RandomNumberGenerator;
namespace TLS {
class Callbacks;
class Policy;
} // namespace TLS
} // namespace Botan
namespace Botan::TLS {
/**
* Generate a (client) hello random value.
*
* Depending on the policy, the RNG output may be hashed and if TLS 1.2 is
* offered, the random value may contain a timestamp.
*/
std::vector<uint8_t> make_hello_random(RandomNumberGenerator& rng, Callbacks& cb, const Policy& policy);
/**
* Generate a server hello random value for the given protocol version.
*
* Depending on the protocol version, the random value is generated differently.
* For instance, TLS 1.2 requested a timestamp in the random value. Also, when
* downgrading to TLS 1.2 from a peer that could also negotiate TLS 1.3, the
* random value must be slightly modified to signal the downgrade.
*/
std::vector<uint8_t> make_server_hello_random(RandomNumberGenerator& rng,
Protocol_Version offered_version,
Callbacks& cb,
const Policy& policy);
/**
* Version-agnostic internal client hello data container that allows
* parsing Client_Hello messages without prior knowledge of the contained
* protocol version.
*/
class Client_Hello_Internal {
public:
Client_Hello_Internal() : m_comp_methods({0}) {}
explicit Client_Hello_Internal(const std::vector<uint8_t>& buf);
/**
* This distinguishes between a TLS 1.3 compliant Client Hello (containing
* the "supported_version" extension) and legacy Client Hello messages.
*
* @return TLS 1.3 if the Client Hello contains "supported_versions", or
* the content of the "legacy_version" version field if it
* indicates (D)TLS 1.2 or older, or
* (D)TLS 1.2 if the "legacy_version" was some other odd value.
*/
Protocol_Version version() const;
Protocol_Version legacy_version() const { return m_legacy_version; }
const Session_ID& session_id() const { return m_session_id; }
const std::vector<uint8_t>& random() const { return m_random; }
const std::vector<uint16_t>& ciphersuites() const { return m_suites; }
const std::vector<uint8_t>& comp_methods() const { return m_comp_methods; }
const std::vector<uint8_t>& hello_cookie() const { return m_hello_cookie; }
const std::vector<uint8_t>& hello_cookie_input_bits() const { return m_cookie_input_bits; }
const Extensions& extensions() const { return m_extensions; }
Extensions& extensions() { return m_extensions; }
public:
Protocol_Version m_legacy_version; // NOLINT(*-non-private-member-variable*)
Session_ID m_session_id; // NOLINT(*-non-private-member-variable*)
std::vector<uint8_t> m_random; // NOLINT(*-non-private-member-variable*)
std::vector<uint16_t> m_suites; // NOLINT(*-non-private-member-variable*)
std::vector<uint8_t> m_comp_methods; // NOLINT(*-non-private-member-variable*)
Extensions m_extensions; // NOLINT(*-non-private-member-variable*)
// These fields are only for DTLS:
std::vector<uint8_t> m_hello_cookie; // NOLINT(*-non-private-member-variable*)
std::vector<uint8_t> m_cookie_input_bits; // NOLINT(*-non-private-member-variable*)
};
/**
* Version-agnostic internal server hello data container that allows
* parsing Server_Hello messages without prior knowledge of the contained
* protocol version.
*/
class Server_Hello_Internal final {
public:
/**
* Deserialize a Server Hello message
*/
explicit Server_Hello_Internal(const std::vector<uint8_t>& buf);
Server_Hello_Internal(Protocol_Version lv,
Session_ID sid,
std::vector<uint8_t> r,
const uint16_t cs,
const uint8_t cm,
bool is_hrr = false) :
m_legacy_version(lv),
m_session_id(std::move(sid)),
m_random(std::move(r)),
m_is_hello_retry_request(is_hrr),
m_ciphersuite(cs),
m_comp_method(cm) {}
Protocol_Version version() const;
Protocol_Version legacy_version() const { return m_legacy_version; }
const Session_ID& session_id() const { return m_session_id; }
const std::vector<uint8_t>& random() const { return m_random; }
uint16_t ciphersuite() const { return m_ciphersuite; }
uint8_t comp_method() const { return m_comp_method; }
bool is_hello_retry_request() const { return m_is_hello_retry_request; }
const Extensions& extensions() const { return m_extensions; }
Extensions& extensions() { return m_extensions; }
private:
Protocol_Version m_legacy_version;
Session_ID m_session_id;
std::vector<uint8_t> m_random;
bool m_is_hello_retry_request;
uint16_t m_ciphersuite;
uint8_t m_comp_method;
Extensions m_extensions;
};
} // namespace Botan::TLS
#endif