Botan 3.10.0
Crypto and TLS for C&
Public Member Functions | Static Public Member Functions | Protected Member Functions | Protected Attributes | Static Protected Attributes | Friends | List of all members
Botan::TLS::Hello_Retry_Request Class Referencefinal

#include <tls_messages.h>

Inheritance diagram for Botan::TLS::Hello_Retry_Request:
Botan::TLS::Server_Hello_13 Botan::TLS::Server_Hello Botan::TLS::Handshake_Message

Public Member Functions

uint16_t ciphersuite () const
const Extensions & extensions () const
std::optional< Protocol_Version > random_signals_downgrade () const
Protocol_Version selected_version () const final
std::vector< uint8_t > serialize () const override
const Session_ID & session_id () const
Handshake_Type type () const override
std::string type_string () const
Handshake_Type wire_type () const override

Static Public Member Functions

static std::variant< Hello_Retry_Request, Server_Hello_13 > create (const Client_Hello_13 &ch, bool hello_retry_request_allowed, Session_Manager &session_mgr, Credentials_Manager &credentials_mgr, RandomNumberGenerator &rng, const Policy &policy, Callbacks &cb)
static std::variant< Hello_Retry_Request, Server_Hello_13, Server_Hello_12 > parse (const std::vector< uint8_t > &buf)

Protected Member Functions

void basic_validation () const
uint8_t compression_method () const
std::set< Extension_Code > extension_types () const
 Hello_Retry_Request (const Client_Hello_13 &ch, Named_Group selected_group, const Policy &policy, Callbacks &cb)
 Hello_Retry_Request (std::unique_ptr< Server_Hello_Internal > data)
Protocol_Version legacy_version () const
const std::vector< uint8_t > & random () const

Protected Attributes

std::unique_ptr< Server_Hello_Internal > m_data

Static Protected Attributes

static const struct Botan::TLS::Server_Hello_13::Hello_Retry_Request_Tag as_hello_retry_request
static const struct Botan::TLS::Server_Hello_13::Hello_Retry_Request_Creation_Tag as_new_hello_retry_request
static const struct Botan::TLS::Server_Hello_13::Server_Hello_Tag as_server_hello

Friends

class Server_Hello_13

Detailed Description

Definition at line 453 of file tls_messages.h.

Constructor & Destructor Documentation

◆ Hello_Retry_Request() [1/2]

Botan::TLS::Hello_Retry_Request::Hello_Retry_Request ( std::unique_ptr< Server_Hello_Internal > data)
explicitprotected

Definition at line 788 of file msg_server_hello.cpp.

788 :
789 Server_Hello_13(std::move(data), Server_Hello_13::as_hello_retry_request) {}
Botan::TLS::Hello_Retry_Request::Server_Hello_13
friend class Server_Hello_13
Definition tls_messages.h:455
Botan::TLS::Server_Hello_13::as_hello_retry_request
static const struct Botan::TLS::Server_Hello_13::Hello_Retry_Request_Tag as_hello_retry_request
Definition msg_server_hello.cpp:457

References Botan::TLS::Server_Hello_13::as_hello_retry_request, and Server_Hello_13.

Referenced by Server_Hello_13.

◆ Hello_Retry_Request() [2/2]

Botan::TLS::Hello_Retry_Request::Hello_Retry_Request ( const Client_Hello_13 & ch,
Named_Group selected_group,
const Policy & policy,
Callbacks & cb )
protected

Definition at line 791 of file msg_server_hello.cpp.

794 :
795 Server_Hello_13(std::make_unique<Server_Hello_Internal>(
796 Protocol_Version::TLS_V12 /* legacy_version */,
797 ch.session_id(),
798 std::vector<uint8_t>(HELLO_RETRY_REQUEST_MARKER.begin(), HELLO_RETRY_REQUEST_MARKER.end()),
799 choose_ciphersuite(ch, policy),
800 uint8_t(0) /* compression method */,
801 true /* is Hello Retry Request */
802 ),
803 as_new_hello_retry_request) {
804 // RFC 8446 4.1.4
805 // As with the ServerHello, a HelloRetryRequest MUST NOT contain any
806 // extensions that were not first offered by the client in its
807 // ClientHello, with the exception of optionally the "cookie" [...]
808 // extension.
809 BOTAN_STATE_CHECK(ch.extensions().has<Supported_Groups>());
810 BOTAN_STATE_CHECK(ch.extensions().has<Key_Share>());
811
812 BOTAN_STATE_CHECK(!value_exists(ch.extensions().get<Key_Share>()->offered_groups(), selected_group));
813
814 // RFC 8446 4.1.4
815 // The server's extensions MUST contain "supported_versions".
816 //
817 // RFC 8446 4.2.1
818 // A server which negotiates TLS 1.3 MUST respond by sending a
819 // "supported_versions" extension containing the selected version
820 // value (0x0304). It MUST set the ServerHello.legacy_version field to
821 // 0x0303 (TLS 1.2).
822 //
823 // Note that the legacy version (TLS 1.2) is set in this constructor's
824 // initializer list, accordingly.
825 // NOLINTBEGIN(*-owning-memory)
826 m_data->extensions().add(new Supported_Versions(Protocol_Version::TLS_V13));
827
828 m_data->extensions().add(new Key_Share(selected_group));
829 // NOLINTEND(*-owning-memory)
830
831 cb.tls_modify_extensions(m_data->extensions(), Connection_Side::Server, type());
832}
BOTAN_STATE_CHECK
#define BOTAN_STATE_CHECK(expr)
Definition assert.h:49
Botan::TLS::Hello_Retry_Request::type
Handshake_Type type() const override
Definition tls_messages.h:460
Botan::TLS::Server_Hello_13::as_new_hello_retry_request
static const struct Botan::TLS::Server_Hello_13::Hello_Retry_Request_Creation_Tag as_new_hello_retry_request
Definition msg_server_hello.cpp:458
Botan::TLS::Server_Hello::m_data
std::unique_ptr< Server_Hello_Internal > m_data
Definition tls_messages.h:304
Botan::value_exists
bool value_exists(const std::vector< T > &vec, const V &val)
Definition stl_util.h:51

References Botan::TLS::Server_Hello_13::as_new_hello_retry_request, BOTAN_STATE_CHECK, Botan::TLS::Client_Hello::extensions(), Botan::TLS::Extensions::get(), Botan::TLS::Extensions::has(), Botan::TLS::Server_Hello::m_data, Botan::TLS::Key_Share::offered_groups(), Botan::TLS::Server, Server_Hello_13, Botan::TLS::Server_Hello::session_id(), Botan::TLS::Callbacks::tls_modify_extensions(), type(), and Botan::value_exists().

Member Function Documentation

◆ basic_validation()

void Botan::TLS::Server_Hello_13::basic_validation ( ) const
protectedinherited

Validation that applies to both Server Hello and Hello Retry Request

Definition at line 541 of file msg_server_hello.cpp.

541 {
542 BOTAN_ASSERT_NOMSG(m_data->version() == Protocol_Version::TLS_V13);
543
544 // Note: checks that cannot be performed without contextual information
545 // are done in the specific TLS client implementation.
546 // Note: The Supported_Version extension makes sure internally that
547 // exactly one entry is provided.
548
549 // Note: Hello Retry Request basic validation is equivalent with the
550 // basic validations required for Server Hello
551 //
552 // RFC 8446 4.1.4
553 // Upon receipt of a HelloRetryRequest, the client MUST check the
554 // legacy_version, [...], and legacy_compression_method as specified in
555 // Section 4.1.3 and then process the extensions, starting with determining
556 // the version using "supported_versions".
557
558 // RFC 8446 4.1.3
559 // In TLS 1.3, [...] the legacy_version field MUST be set to 0x0303
560 if(legacy_version() != Protocol_Version::TLS_V12) {
561 throw TLS_Exception(Alert::ProtocolVersion,
562 "legacy_version '" + legacy_version().to_string() + "' is not allowed");
563 }
564
565 // RFC 8446 4.1.3
566 // legacy_compression_method: A single byte which MUST have the value 0.
567 if(compression_method() != 0x00) {
568 throw TLS_Exception(Alert::DecodeError, "compression is not supported in TLS 1.3");
569 }
570
571 // RFC 8446 4.1.3
572 // All TLS 1.3 ServerHello messages MUST contain the "supported_versions" extension.
573 if(!extensions().has<Supported_Versions>()) {
574 throw TLS_Exception(Alert::MissingExtension, "server hello did not contain 'supported version' extension");
575 }
576
577 // RFC 8446 4.2.1
578 // A server which negotiates TLS 1.3 MUST respond by sending
579 // a "supported_versions" extension containing the selected version
580 // value (0x0304).
581 if(selected_version() != Protocol_Version::TLS_V13) {
582 throw TLS_Exception(Alert::IllegalParameter, "TLS 1.3 Server Hello selected a different version");
583 }
584}
BOTAN_ASSERT_NOMSG
#define BOTAN_ASSERT_NOMSG(expr)
Definition assert.h:75
Botan::TLS::Server_Hello_13::selected_version
Protocol_Version selected_version() const final
Definition msg_server_hello.cpp:780
Botan::TLS::Server_Hello::compression_method
uint8_t compression_method() const
Definition msg_server_hello.cpp:207
Botan::TLS::Server_Hello::extensions
const Extensions & extensions() const
Definition msg_server_hello.cpp:223
Botan::TLS::Server_Hello::legacy_version
Protocol_Version legacy_version() const
Definition msg_server_hello.cpp:199
Botan::to_string
std::string to_string(ErrorType type)
Convert an ErrorType to string.
Definition exceptn.cpp:13

References BOTAN_ASSERT_NOMSG, Botan::TLS::Server_Hello::compression_method(), Botan::TLS::Server_Hello::extensions(), Botan::TLS::Server_Hello::legacy_version(), Botan::TLS::Server_Hello::m_data, selected_version(), and Botan::to_string().

Referenced by Server_Hello_13(), and Server_Hello_13().

◆ ciphersuite()

uint16_t Botan::TLS::Server_Hello::ciphersuite ( ) const
inherited

Definition at line 215 of file msg_server_hello.cpp.

215 {
216 return m_data->ciphersuite();
217}

References m_data.

Referenced by Botan::TLS::Client_Hello_13::retry(), Botan::TLS::Server_Hello_12::Server_Hello_12(), and ~Server_Hello().

◆ compression_method()

uint8_t Botan::TLS::Server_Hello::compression_method ( ) const
protectedinherited

Definition at line 207 of file msg_server_hello.cpp.

207 {
208 return m_data->comp_method();
209}

References m_data.

Referenced by Botan::TLS::Server_Hello_13::basic_validation(), selected_version(), and Botan::TLS::Server_Hello_12::Server_Hello_13.

◆ create()

std::variant< Hello_Retry_Request, Server_Hello_13 > Botan::TLS::Server_Hello_13::create ( const Client_Hello_13 & ch,
bool hello_retry_request_allowed,
Session_Manager & session_mgr,
Credentials_Manager & credentials_mgr,
RandomNumberGenerator & rng,
const Policy & policy,
Callbacks & cb )
staticinherited

Definition at line 460 of file msg_server_hello.cpp.

466 {
467 const auto& exts = ch.extensions();
468
469 // RFC 8446 4.2.9
470 // [With PSK with (EC)DHE key establishment], the client and server MUST
471 // supply "key_share" values [...].
472 //
473 // Note: We currently do not support PSK without (EC)DHE, hence, we can
474 // assume that those extensions are available.
475 BOTAN_ASSERT_NOMSG(exts.has<Supported_Groups>() && exts.has<Key_Share>());
476 const auto& supported_by_client = exts.get<Supported_Groups>()->groups();
477 const auto& offered_by_client = exts.get<Key_Share>()->offered_groups();
478 const auto selected_group = policy.choose_key_exchange_group(supported_by_client, offered_by_client);
479
480 // RFC 8446 4.1.1
481 // If there is no overlap between the received "supported_groups" and the
482 // groups supported by the server, then the server MUST abort the
483 // handshake with a "handshake_failure" or an "insufficient_security" alert.
484 if(selected_group == Named_Group::NONE) {
485 throw TLS_Exception(Alert::HandshakeFailure, "Client did not offer any acceptable group");
486 }
487
488 // RFC 8446 4.2.8:
489 // Servers MUST NOT send a KeyShareEntry for any group not indicated in the
490 // client's "supported_groups" extension [...]
491 if(!value_exists(supported_by_client, selected_group)) {
492 throw TLS_Exception(Alert::InternalError, "Application selected a group that is not supported by the client");
493 }
494
495 // RFC 8446 4.1.4
496 // The server will send this message in response to a ClientHello
497 // message if it is able to find an acceptable set of parameters but the
498 // ClientHello does not contain sufficient information to proceed with
499 // the handshake.
500 //
501 // In this case, the Client Hello did not contain a key share offer for
502 // the group selected by the application.
503 if(!value_exists(offered_by_client, selected_group)) {
504 // RFC 8446 4.1.4
505 // If a client receives a second HelloRetryRequest in the same
506 // connection (i.e., where the ClientHello was itself in response to a
507 // HelloRetryRequest), it MUST abort the handshake with an
508 // "unexpected_message" alert.
509 BOTAN_STATE_CHECK(hello_retry_request_allowed);
510 return Hello_Retry_Request(ch, selected_group, policy, cb);
511 } else {
512 return Server_Hello_13(ch, selected_group, session_mgr, credentials_mgr, rng, cb, policy);
513 }
514}
Botan::TLS::Server_Hello_13::Server_Hello_13
Server_Hello_13(std::unique_ptr< Server_Hello_Internal > data, Server_Hello_Tag tag=as_server_hello)
Definition msg_server_hello.cpp:586

References BOTAN_ASSERT_NOMSG, BOTAN_STATE_CHECK, Botan::TLS::Policy::choose_key_exchange_group(), Botan::TLS::Client_Hello::extensions(), Server_Hello_13(), and Botan::value_exists().

◆ extension_types()

std::set< Extension_Code > Botan::TLS::Server_Hello::extension_types ( ) const
protectedinherited

Definition at line 219 of file msg_server_hello.cpp.

219 {
220 return m_data->extensions().extension_types();
221}

References m_data.

Referenced by selected_version(), and Botan::TLS::Server_Hello_12::Server_Hello_13.

◆ extensions()

const Extensions & Botan::TLS::Server_Hello::extensions ( ) const
inherited

Definition at line 223 of file msg_server_hello.cpp.

223 {
224 return m_data->extensions();
225}

References m_data.

Referenced by Botan::TLS::Server_Hello_13::basic_validation(), Botan::TLS::Client_Hello_13::retry(), Botan::TLS::Server_Hello_13::Server_Hello_13(), Botan::TLS::Server_Hello_13::Server_Hello_13(), and ~Server_Hello().

◆ legacy_version()

Protocol_Version Botan::TLS::Server_Hello::legacy_version ( ) const
protectedinherited

Definition at line 199 of file msg_server_hello.cpp.

199 {
200 return m_data->legacy_version();
201}

References m_data.

Referenced by Botan::TLS::Server_Hello_13::basic_validation(), selected_version(), and Botan::TLS::Server_Hello_12::Server_Hello_13.

◆ parse()

std::variant< Hello_Retry_Request, Server_Hello_13, Server_Hello_12 > Botan::TLS::Server_Hello_13::parse ( const std::vector< uint8_t > & buf)
staticinherited

Definition at line 516 of file msg_server_hello.cpp.

517 {
518 auto data = std::make_unique<Server_Hello_Internal>(buf);
519 const auto version = data->version();
520
521 // server hello that appears to be pre-TLS 1.3, takes precedence over...
522 if(version.is_pre_tls_13()) {
523 return Server_Hello_12(std::move(data));
524 }
525
526 // ... the TLS 1.3 "special case" aka. Hello_Retry_Request
527 if(version == Protocol_Version::TLS_V13) {
528 if(data->is_hello_retry_request()) {
529 return Hello_Retry_Request(std::move(data));
530 }
531
532 return Server_Hello_13(std::move(data));
533 }
534
535 throw TLS_Exception(Alert::ProtocolVersion, "unexpected server hello version: " + version.to_string());
536}

References Server_Hello_13().

◆ random()

const std::vector< uint8_t > & Botan::TLS::Server_Hello::random ( ) const
protectedinherited

Definition at line 203 of file msg_server_hello.cpp.

203 {
204 return m_data->random();
205}

References m_data.

Referenced by selected_version(), and Botan::TLS::Server_Hello_12::Server_Hello_13.

◆ random_signals_downgrade()

std::optional< Protocol_Version > Botan::TLS::Server_Hello_13::random_signals_downgrade ( ) const
inherited

Return desired downgrade version indicated by hello random, if any.

Definition at line 768 of file msg_server_hello.cpp.

768 {
769 const uint64_t last8 = load_be<uint64_t>(m_data->random().data(), 3);
770 if(last8 == DOWNGRADE_TLS11) {
771 return Protocol_Version::TLS_V11;
772 }
773 if(last8 == DOWNGRADE_TLS12) {
774 return Protocol_Version::TLS_V12;
775 }
776
777 return std::nullopt;
778}
Botan::load_be
constexpr auto load_be(ParamTs &&... params)
Definition loadstor.h:504

References Botan::load_be(), and Botan::TLS::Server_Hello::m_data.

◆ selected_version()

Protocol_Version Botan::TLS::Server_Hello_13::selected_version ( ) const
finalvirtualinherited
Returns
the selected version as indicated by the supported_versions extension

Implements Botan::TLS::Server_Hello.

Definition at line 780 of file msg_server_hello.cpp.

780 {
781 auto* const versions_ext = m_data->extensions().get<Supported_Versions>();
782 BOTAN_ASSERT_NOMSG(versions_ext);
783 const auto& versions = versions_ext->versions();
784 BOTAN_ASSERT_NOMSG(versions.size() == 1);
785 return versions.front();
786}

References BOTAN_ASSERT_NOMSG, and Botan::TLS::Server_Hello::m_data.

Referenced by basic_validation().

◆ serialize()

std::vector< uint8_t > Botan::TLS::Server_Hello::serialize ( ) const
overridevirtualinherited
Returns
DER representation of this message

Implements Botan::TLS::Handshake_Message.

Definition at line 175 of file msg_server_hello.cpp.

175 {
176 std::vector<uint8_t> buf;
177 buf.reserve(1024); // working around GCC warning
178
179 buf.push_back(m_data->legacy_version().major_version());
180 buf.push_back(m_data->legacy_version().minor_version());
181 buf += m_data->random();
182
183 append_tls_length_value(buf, m_data->session_id().get(), 1);
184
185 buf.push_back(get_byte<0>(m_data->ciphersuite()));
186 buf.push_back(get_byte<1>(m_data->ciphersuite()));
187
188 buf.push_back(m_data->comp_method());
189
190 buf += m_data->extensions().serialize(Connection_Side::Server);
191
192 return buf;
193}
Botan::TLS::append_tls_length_value
void append_tls_length_value(std::vector< uint8_t, Alloc > &buf, const T *vals, size_t vals_size, size_t tag_size)
Definition tls_reader.h:184
Botan::get_byte
constexpr uint8_t get_byte(T input)
Definition loadstor.h:79

References Botan::TLS::append_tls_length_value(), Botan::get_byte(), m_data, serialize(), Botan::TLS::Server, and Server_Hello().

Referenced by serialize(), and ~Server_Hello().

◆ session_id()

const Session_ID & Botan::TLS::Server_Hello::session_id ( ) const
inherited

Definition at line 211 of file msg_server_hello.cpp.

211 {
212 return m_data->session_id();
213}

References m_data.

Referenced by Botan::TLS::Hello_Retry_Request::Hello_Retry_Request(), Botan::TLS::Server_Hello_12::Server_Hello_12(), Botan::TLS::Server_Hello_12::Server_Hello_12(), Botan::TLS::Server_Hello_13::Server_Hello_13(), and ~Server_Hello().

◆ type()

Handshake_Type Botan::TLS::Hello_Retry_Request::type ( ) const
inlineoverridevirtual
Returns
the message type

Implements Botan::TLS::Handshake_Message.

Definition at line 460 of file tls_messages.h.

460{ return Handshake_Type::HelloRetryRequest; }

References Botan::TLS::HelloRetryRequest.

Referenced by Hello_Retry_Request().

◆ type_string()

std::string Botan::TLS::Handshake_Message::type_string ( ) const
inherited
Returns
string representation of this message type

Definition at line 18 of file tls_handshake_state.cpp.

18 {
19 return handshake_type_to_string(type());
20}
Botan::TLS::Handshake_Message::type
virtual Handshake_Type type() const =0
Botan::TLS::handshake_type_to_string
const char * handshake_type_to_string(Handshake_Type type)
Definition tls_handshake_state.cpp:22

References Botan::TLS::handshake_type_to_string(), and type().

◆ wire_type()

Handshake_Type Botan::TLS::Hello_Retry_Request::wire_type ( ) const
inlineoverridevirtual
Returns
the wire representation of the message's type

Reimplemented from Botan::TLS::Handshake_Message.

Definition at line 462 of file tls_messages.h.

462{ return Handshake_Type::ServerHello; }

References Botan::TLS::ServerHello.

◆ Server_Hello_13

friend class Server_Hello_13
friend

Definition at line 455 of file tls_messages.h.

References Hello_Retry_Request(), and Server_Hello_13.

Referenced by Hello_Retry_Request(), Hello_Retry_Request(), and Server_Hello_13.

Member Data Documentation

◆ as_hello_retry_request

const Server_Hello_13::Hello_Retry_Request_Tag Botan::TLS::Server_Hello_13::as_hello_retry_request
staticprotectedinherited

Definition at line 457 of file msg_server_hello.cpp.

Referenced by Botan::TLS::Hello_Retry_Request::Hello_Retry_Request().

◆ as_new_hello_retry_request

const Server_Hello_13::Hello_Retry_Request_Creation_Tag Botan::TLS::Server_Hello_13::as_new_hello_retry_request
staticprotectedinherited

Definition at line 458 of file msg_server_hello.cpp.

Referenced by Botan::TLS::Hello_Retry_Request::Hello_Retry_Request().

◆ as_server_hello

const Server_Hello_13::Server_Hello_Tag Botan::TLS::Server_Hello_13::as_server_hello
staticprotectedinherited

Definition at line 456 of file msg_server_hello.cpp.

◆ m_data

std::unique_ptr<Server_Hello_Internal> Botan::TLS::Server_Hello::m_data
protectedinherited

Definition at line 304 of file tls_messages.h.

Referenced by Botan::TLS::Server_Hello_13::basic_validation(), ciphersuite(), compression_method(), extension_types(), extensions(), Botan::TLS::Hello_Retry_Request::Hello_Retry_Request(), legacy_version(), Botan::TLS::Server_Hello_12::next_protocol(), Botan::TLS::Server_Hello_12::prefers_compressed_ec_points(), random(), Botan::TLS::Server_Hello_12::random_signals_downgrade(), Botan::TLS::Server_Hello_13::random_signals_downgrade(), Botan::TLS::Server_Hello_12::renegotiation_info(), Botan::TLS::Server_Hello_12::secure_renegotiation(), Botan::TLS::Server_Hello_13::selected_version(), serialize(), Server_Hello(), Botan::TLS::Server_Hello_12::Server_Hello_12(), Botan::TLS::Server_Hello_12::Server_Hello_12(), Botan::TLS::Server_Hello_13::Server_Hello_13(), Botan::TLS::Server_Hello_13::Server_Hello_13(), Botan::TLS::Server_Hello_13::Server_Hello_13(), session_id(), Botan::TLS::Server_Hello_12::srtp_profile(), Botan::TLS::Server_Hello_12::supports_certificate_status_message(), Botan::TLS::Server_Hello_12::supports_encrypt_then_mac(), Botan::TLS::Server_Hello_12::supports_extended_master_secret(), and Botan::TLS::Server_Hello_12::supports_session_ticket().

The documentation for this class was generated from the following files:
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