diff options
Diffstat (limited to 'lib/tls/tls_client.cpp')
| -rw-r--r-- | lib/tls/tls_client.cpp | 530 |
1 files changed, 530 insertions, 0 deletions
diff --git a/lib/tls/tls_client.cpp b/lib/tls/tls_client.cpp new file mode 100644 index 000000000..f17247c16 --- /dev/null +++ b/lib/tls/tls_client.cpp @@ -0,0 +1,530 @@ +/* +* TLS Client +* (C) 2004-2011,2012 Jack Lloyd +* +* Released under the terms of the Botan license +*/ + +#include <botan/tls_client.h> +#include <botan/internal/tls_handshake_state.h> +#include <botan/internal/tls_messages.h> +#include <botan/internal/stl_util.h> +#include <memory> + +namespace Botan { + +namespace TLS { + +namespace { + +class Client_Handshake_State : public Handshake_State + { + public: + // using Handshake_State::Handshake_State; + + Client_Handshake_State(Handshake_IO* io, + std::function<void (const Handshake_Message&)> msg_callback = + std::function<void (const Handshake_Message&)>()) : + Handshake_State(io, msg_callback) {} + + const Public_Key& get_server_public_Key() const + { + BOTAN_ASSERT(server_public_key, "Server sent us a certificate"); + return *server_public_key.get(); + } + + // Used during session resumption + secure_vector<byte> resume_master_secret; + + std::unique_ptr<Public_Key> server_public_key; + + // Used by client using NPN + std::function<std::string (std::vector<std::string>)> client_npn_cb; + }; + +} + +/* +* TLS Client Constructor +*/ +Client::Client(std::function<void (const byte[], size_t)> output_fn, + std::function<void (const byte[], size_t)> proc_cb, + std::function<void (Alert, const byte[], size_t)> alert_cb, + std::function<bool (const Session&)> handshake_cb, + Session_Manager& session_manager, + Credentials_Manager& creds, + const Policy& policy, + RandomNumberGenerator& rng, + const Server_Information& info, + const Protocol_Version offer_version, + std::function<std::string (std::vector<std::string>)> next_protocol, + size_t io_buf_sz) : + Channel(output_fn, proc_cb, alert_cb, handshake_cb, session_manager, rng, io_buf_sz), + m_policy(policy), + m_creds(creds), + m_info(info) + { + const std::string srp_identifier = m_creds.srp_identifier("tls-client", m_info.hostname()); + + Handshake_State& state = create_handshake_state(offer_version); + send_client_hello(state, false, offer_version, srp_identifier, next_protocol); + } + +Handshake_State* Client::new_handshake_state(Handshake_IO* io) + { + return new Client_Handshake_State(io); + } + +std::vector<X509_Certificate> +Client::get_peer_cert_chain(const Handshake_State& state) const + { + if(state.server_certs()) + return state.server_certs()->cert_chain(); + return std::vector<X509_Certificate>(); + } + +/* +* Send a new client hello to renegotiate +*/ +void Client::initiate_handshake(Handshake_State& state, + bool force_full_renegotiation) + { + send_client_hello(state, + force_full_renegotiation, + state.version()); + } + +void Client::send_client_hello(Handshake_State& state_base, + bool force_full_renegotiation, + Protocol_Version version, + const std::string& srp_identifier, + std::function<std::string (std::vector<std::string>)> next_protocol) + { + Client_Handshake_State& state = dynamic_cast<Client_Handshake_State&>(state_base); + + if(state.version().is_datagram_protocol()) + state.set_expected_next(HELLO_VERIFY_REQUEST); // optional + state.set_expected_next(SERVER_HELLO); + + state.client_npn_cb = next_protocol; + + const bool send_npn_request = static_cast<bool>(next_protocol); + + if(!force_full_renegotiation && !m_info.empty()) + { + Session session_info; + if(session_manager().load_from_server_info(m_info, session_info)) + { + if(srp_identifier == "" || session_info.srp_identifier() == srp_identifier) + { + state.client_hello(new Client_Hello( + state.handshake_io(), + state.hash(), + m_policy, + rng(), + secure_renegotiation_data_for_client_hello(), + session_info, + send_npn_request)); + + state.resume_master_secret = session_info.master_secret(); + } + } + } + + if(!state.client_hello()) // not resuming + { + state.client_hello(new Client_Hello( + state.handshake_io(), + state.hash(), + version, + m_policy, + rng(), + secure_renegotiation_data_for_client_hello(), + send_npn_request, + m_info.hostname(), + srp_identifier)); + } + + secure_renegotiation_check(state.client_hello()); + } + +/* +* Process a handshake message +*/ +void Client::process_handshake_msg(const Handshake_State* active_state, + Handshake_State& state_base, + Handshake_Type type, + const std::vector<byte>& contents) + { + Client_Handshake_State& state = dynamic_cast<Client_Handshake_State&>(state_base); + + if(type == HELLO_REQUEST && active_state) + { + Hello_Request hello_request(contents); + + // Ignore request entirely if we are currently negotiating a handshake + if(state.client_hello()) + return; + + if(!m_policy.allow_server_initiated_renegotiation() || + (!m_policy.allow_insecure_renegotiation() && !secure_renegotiation_supported())) + { + // RFC 5746 section 4.2 + send_warning_alert(Alert::NO_RENEGOTIATION); + return; + } + + this->initiate_handshake(state, false); + + return; + } + + state.confirm_transition_to(type); + + if(type != HANDSHAKE_CCS && type != FINISHED && type != HELLO_VERIFY_REQUEST) + state.hash().update(state.handshake_io().format(contents, type)); + + if(type == HELLO_VERIFY_REQUEST) + { + state.set_expected_next(SERVER_HELLO); + state.set_expected_next(HELLO_VERIFY_REQUEST); // might get it again + + Hello_Verify_Request hello_verify_request(contents); + + state.hello_verify_request(hello_verify_request); + } + else if(type == SERVER_HELLO) + { + state.server_hello(new Server_Hello(contents)); + + if(!state.client_hello()->offered_suite(state.server_hello()->ciphersuite())) + { + throw TLS_Exception(Alert::HANDSHAKE_FAILURE, + "Server replied with ciphersuite we didn't send"); + } + + if(!value_exists(state.client_hello()->compression_methods(), + state.server_hello()->compression_method())) + { + throw TLS_Exception(Alert::HANDSHAKE_FAILURE, + "Server replied with compression method we didn't send"); + } + + if(!state.client_hello()->next_protocol_notification() && + state.server_hello()->next_protocol_notification()) + { + throw TLS_Exception(Alert::HANDSHAKE_FAILURE, + "Server sent next protocol but we didn't request it"); + } + + if(state.server_hello()->supports_session_ticket()) + { + if(!state.client_hello()->supports_session_ticket()) + throw TLS_Exception(Alert::HANDSHAKE_FAILURE, + "Server sent session ticket extension but we did not"); + } + + state.set_version(state.server_hello()->version()); + + secure_renegotiation_check(state.server_hello()); + + const bool server_returned_same_session_id = + !state.server_hello()->session_id().empty() && + (state.server_hello()->session_id() == state.client_hello()->session_id()); + + if(server_returned_same_session_id) + { + // successful resumption + + /* + * In this case, we offered the version used in the original + * session, and the server must resume with the same version. + */ + if(state.server_hello()->version() != state.client_hello()->version()) + throw TLS_Exception(Alert::HANDSHAKE_FAILURE, + "Server resumed session but with wrong version"); + + state.compute_session_keys(state.resume_master_secret); + + if(state.server_hello()->supports_session_ticket()) + state.set_expected_next(NEW_SESSION_TICKET); + else + state.set_expected_next(HANDSHAKE_CCS); + } + else + { + // new session + + if(state.client_hello()->version().is_datagram_protocol() != + state.server_hello()->version().is_datagram_protocol()) + { + throw TLS_Exception(Alert::PROTOCOL_VERSION, + "Server replied with different protocol type than we offered"); + } + + if(state.version() > state.client_hello()->version()) + { + throw TLS_Exception(Alert::HANDSHAKE_FAILURE, + "Server replied with later version than in hello"); + } + + if(!m_policy.acceptable_protocol_version(state.version())) + { + throw TLS_Exception(Alert::PROTOCOL_VERSION, + "Server version is unacceptable by policy"); + } + + if(state.ciphersuite().sig_algo() != "") + { + state.set_expected_next(CERTIFICATE); + } + else if(state.ciphersuite().kex_algo() == "PSK") + { + /* PSK is anonymous so no certificate/cert req message is + ever sent. The server may or may not send a server kex, + depending on if it has an identity hint for us. + + (EC)DHE_PSK always sends a server key exchange for the + DH exchange portion. + */ + + state.set_expected_next(SERVER_KEX); + state.set_expected_next(SERVER_HELLO_DONE); + } + else if(state.ciphersuite().kex_algo() != "RSA") + { + state.set_expected_next(SERVER_KEX); + } + else + { + state.set_expected_next(CERTIFICATE_REQUEST); // optional + state.set_expected_next(SERVER_HELLO_DONE); + } + } + } + else if(type == CERTIFICATE) + { + if(state.ciphersuite().kex_algo() != "RSA") + { + state.set_expected_next(SERVER_KEX); + } + else + { + state.set_expected_next(CERTIFICATE_REQUEST); // optional + state.set_expected_next(SERVER_HELLO_DONE); + } + + state.server_certs(new Certificate(contents)); + + const std::vector<X509_Certificate>& server_certs = + state.server_certs()->cert_chain(); + + if(server_certs.empty()) + throw TLS_Exception(Alert::HANDSHAKE_FAILURE, + "Client: No certificates sent by server"); + + try + { + m_creds.verify_certificate_chain("tls-client", m_info.hostname(), server_certs); + } + catch(std::exception& e) + { + throw TLS_Exception(Alert::BAD_CERTIFICATE, e.what()); + } + + std::unique_ptr<Public_Key> peer_key(server_certs[0].subject_public_key()); + + if(peer_key->algo_name() != state.ciphersuite().sig_algo()) + throw TLS_Exception(Alert::ILLEGAL_PARAMETER, + "Certificate key type did not match ciphersuite"); + + state.server_public_key.reset(peer_key.release()); + } + else if(type == SERVER_KEX) + { + state.set_expected_next(CERTIFICATE_REQUEST); // optional + state.set_expected_next(SERVER_HELLO_DONE); + + state.server_kex( + new Server_Key_Exchange(contents, + state.ciphersuite().kex_algo(), + state.ciphersuite().sig_algo(), + state.version()) + ); + + if(state.ciphersuite().sig_algo() != "") + { + const Public_Key& server_key = state.get_server_public_Key(); + + if(!state.server_kex()->verify(server_key, state)) + { + throw TLS_Exception(Alert::DECRYPT_ERROR, + "Bad signature on server key exchange"); + } + } + } + else if(type == CERTIFICATE_REQUEST) + { + state.set_expected_next(SERVER_HELLO_DONE); + state.cert_req( + new Certificate_Req(contents, state.version()) + ); + } + else if(type == SERVER_HELLO_DONE) + { + state.server_hello_done( + new Server_Hello_Done(contents) + ); + + if(state.received_handshake_msg(CERTIFICATE_REQUEST)) + { + const std::vector<std::string>& types = + state.cert_req()->acceptable_cert_types(); + + std::vector<X509_Certificate> client_certs = + m_creds.cert_chain(types, + "tls-client", + m_info.hostname()); + + state.client_certs( + new Certificate(state.handshake_io(), + state.hash(), + client_certs) + ); + } + + state.client_kex( + new Client_Key_Exchange(state.handshake_io(), + state, + m_policy, + m_creds, + state.server_public_key.get(), + m_info.hostname(), + rng()) + ); + + state.compute_session_keys(); + + if(state.received_handshake_msg(CERTIFICATE_REQUEST) && + !state.client_certs()->empty()) + { + Private_Key* private_key = + m_creds.private_key_for(state.client_certs()->cert_chain()[0], + "tls-client", + m_info.hostname()); + + state.client_verify( + new Certificate_Verify(state.handshake_io(), + state, + m_policy, + rng(), + private_key) + ); + } + + state.handshake_io().send(Change_Cipher_Spec()); + + change_cipher_spec_writer(CLIENT); + + if(state.server_hello()->next_protocol_notification()) + { + const std::string protocol = state.client_npn_cb( + state.server_hello()->next_protocols()); + + state.next_protocol( + new Next_Protocol(state.handshake_io(), state.hash(), protocol) + ); + } + + state.client_finished( + new Finished(state.handshake_io(), state, CLIENT) + ); + + if(state.server_hello()->supports_session_ticket()) + state.set_expected_next(NEW_SESSION_TICKET); + else + state.set_expected_next(HANDSHAKE_CCS); + } + else if(type == NEW_SESSION_TICKET) + { + state.new_session_ticket(new New_Session_Ticket(contents)); + + state.set_expected_next(HANDSHAKE_CCS); + } + else if(type == HANDSHAKE_CCS) + { + state.set_expected_next(FINISHED); + + change_cipher_spec_reader(CLIENT); + } + else if(type == FINISHED) + { + state.server_finished(new Finished(contents)); + + if(!state.server_finished()->verify(state, SERVER)) + throw TLS_Exception(Alert::DECRYPT_ERROR, + "Finished message didn't verify"); + + state.hash().update(state.handshake_io().format(contents, type)); + + if(!state.client_finished()) // session resume case + { + state.handshake_io().send(Change_Cipher_Spec()); + + change_cipher_spec_writer(CLIENT); + + if(state.server_hello()->next_protocol_notification()) + { + const std::string protocol = state.client_npn_cb( + state.server_hello()->next_protocols()); + + state.next_protocol( + new Next_Protocol(state.handshake_io(), state.hash(), protocol) + ); + } + + state.client_finished( + new Finished(state.handshake_io(), state, CLIENT) + ); + } + + std::vector<byte> session_id = state.server_hello()->session_id(); + + const std::vector<byte>& session_ticket = state.session_ticket(); + + if(session_id.empty() && !session_ticket.empty()) + session_id = make_hello_random(rng()); + + Session session_info( + session_id, + state.session_keys().master_secret(), + state.server_hello()->version(), + state.server_hello()->ciphersuite(), + state.server_hello()->compression_method(), + CLIENT, + state.server_hello()->fragment_size(), + get_peer_cert_chain(state), + session_ticket, + m_info, + "" + ); + + const bool should_save = save_session(session_info); + + if(!session_id.empty()) + { + if(should_save) + session_manager().save(session_info); + else + session_manager().remove_entry(session_info.session_id()); + } + + activate_session(); + } + else + throw Unexpected_Message("Unknown handshake message received"); + } + +} + +} |