9#include <botan/tls_messages.h>
12#include <botan/tls_extensions.h>
14#include <botan/credentials_manager.h>
15#include <botan/internal/ct_utils.h>
16#include <botan/internal/tls_handshake_hash.h>
17#include <botan/internal/tls_handshake_io.h>
18#include <botan/internal/tls_handshake_state.h>
19#include <botan/internal/tls_reader.h>
21#include <botan/ecdh.h>
34 std::string_view hostname,
39 std::string identity_hint;
43 identity_hint = reader.
get_string(2, 0, 65535);
46 const std::string psk_identity = creds.
psk_identity(
"tls-client", std::string(hostname), identity_hint);
50 SymmetricKey psk = creds.
psk(
"tls-client", std::string(hostname), psk_identity);
52 std::vector<uint8_t> zeros(psk.
length());
62 std::string identity_hint = reader.
get_string(2, 0, 65535);
64 const std::string psk_identity = creds.
psk_identity(
"tls-client", std::string(hostname), identity_hint);
68 psk = creds.
psk(
"tls-client", std::string(hostname), psk_identity);
74 const std::vector<uint8_t> peer_public_value = reader.
get_range<uint8_t>(2, 1, 65535);
83 throw TLS_Exception(Alert::InsufficientSecurity,
"DH group validation failed");
91 m_pre_master = std::move(shared_secret);
99 const uint8_t curve_type = reader.
get_byte();
100 if(curve_type != 3) {
105 const std::vector<uint8_t> peer_public_value = reader.
get_range<uint8_t>(1, 1, 255);
108 throw TLS_Exception(Alert::HandshakeFailure,
"Server sent ECC curve prohibited by policy");
120 throw TLS_Exception(Alert::DecryptError,
"Bad X25519 key exchange");
124 m_pre_master = std::move(shared_secret);
133 throw TLS_Exception(Alert::InternalError,
"Application did not provide a ECDH_PublicKey");
136 ecdh_key->public_value(state.
server_hello()->prefers_compressed_ec_points()
144 throw Internal_Error(
"Client_Key_Exchange: Unknown key exchange method was negotiated");
147 reader.assert_done();
152 throw Unexpected_Message(
"No server kex message, but negotiated a key exchange that required it");
155 if(!server_public_key) {
159 if(
auto rsa_pub =
dynamic_cast<const RSA_PublicKey*
>(server_public_key)) {
160 const Protocol_Version offered_version = state.client_hello()->legacy_version();
162 rng.random_vec(m_pre_master, 48);
163 m_pre_master[0] = offered_version.major_version();
164 m_pre_master[1] = offered_version.minor_version();
166 PK_Encryptor_EME encryptor(*rsa_pub, rng,
"PKCS1v15");
168 const std::vector<uint8_t> encrypted_key = encryptor.encrypt(m_pre_master, rng);
172 throw TLS_Exception(Alert::HandshakeFailure,
173 "Expected a RSA key in server cert but got " + server_public_key->algo_name());
177 state.hash().update(io.send(*
this));
183Client_Key_Exchange::Client_Key_Exchange(
const std::vector<uint8_t>& contents,
191 if(kex_algo == Kex_Algo::STATIC_RSA) {
193 "RSA key exchange negotiated so server sent a certificate");
195 if(!server_rsa_kex_key) {
196 throw Internal_Error(
"Expected RSA kex but no server kex key set");
199 if(server_rsa_kex_key->
algo_name() !=
"RSA") {
204 const std::vector<uint8_t> encrypted_pre_master = reader.
get_range<uint8_t>(2, 0, 65535);
209 const uint8_t client_major = state.
client_hello()->legacy_version().major_version();
210 const uint8_t client_minor = state.
client_hello()->legacy_version().minor_version();
218 const size_t expected_plaintext_size = 48;
219 const size_t expected_content_size = 2;
220 const uint8_t expected_content_bytes[expected_content_size] = {client_major, client_minor};
221 const uint8_t expected_content_pos[expected_content_size] = {0, 1};
224 encrypted_pre_master.size(),
225 expected_plaintext_size,
227 expected_content_bytes,
228 expected_content_pos,
229 expected_content_size);
236 const std::string psk_identity = reader.
get_string(2, 0, 65535);
238 psk = creds.
psk(
"tls-server", state.
client_hello()->sni_hostname(), psk_identity);
244 throw TLS_Exception(Alert::UnknownPSKIdentity,
"No PSK for identifier " + psk_identity);
249 if(kex_algo == Kex_Algo::PSK) {
250 std::vector<uint8_t> zeros(psk.
length());
253 }
else if(kex_algo == Kex_Algo::DH || kex_algo == Kex_Algo::ECDH || kex_algo == Kex_Algo::ECDHE_PSK) {
256 const std::vector<uint8_t> client_pubkey = (ka_key.
algo_name() ==
"DH")
260 const auto shared_group = state.
server_kex()->shared_group();
271 if(kex_algo == Kex_Algo::ECDH || kex_algo == Kex_Algo::ECDHE_PSK) {
278 if(group == Group_Params::X25519 &&
CT::all_zeros(shared_secret.data(), shared_secret.size()).is_set()) {
279 throw TLS_Exception(Alert::DecryptError,
"Bad X25519 key exchange");
283 if(kex_algo == Kex_Algo::ECDHE_PSK) {
287 m_pre_master = shared_secret;
294 }
catch(std::exception&) {
306 throw Internal_Error(
"Client_Key_Exchange: Unknown key exchange negotiated");
#define BOTAN_ASSERT_NOMSG(expr)
#define BOTAN_STATE_CHECK(expr)
#define BOTAN_ASSERT(expr, assertion_made)
virtual std::string algo_name() const =0
static BigInt decode(const uint8_t buf[], size_t length)
virtual std::string psk_identity(const std::string &type, const std::string &context, const std::string &identity_hint)
virtual SymmetricKey psk(const std::string &type, const std::string &context, const std::string &identity)
bool verify_group(RandomNumberGenerator &rng, bool strong=true) const
const char * what() const noexcept override
secure_vector< uint8_t > bits_of() const
secure_vector< uint8_t > decrypt_or_random(const uint8_t in[], size_t length, size_t expected_pt_len, RandomNumberGenerator &rng) const
virtual std::vector< uint8_t > public_value() const =0
void random_vec(std::span< uint8_t > v)
virtual secure_vector< uint8_t > tls_ephemeral_key_agreement(const std::variant< TLS::Group_Params, DL_Group > &group, const PK_Key_Agreement_Key &private_key, const std::vector< uint8_t > &public_value, RandomNumberGenerator &rng, const Policy &policy)
virtual std::unique_ptr< PK_Key_Agreement_Key > tls_generate_ephemeral_key(const std::variant< TLS::Group_Params, DL_Group > &group, RandomNumberGenerator &rng)
Kex_Algo kex_method() const
Client_Key_Exchange(Handshake_IO &io, Handshake_State &state, const Policy &policy, Credentials_Manager &creds, const Public_Key *server_public_key, std::string_view hostname, RandomNumberGenerator &rng)
void server_certs(Certificate_12 *server_certs)
void server_hello(Server_Hello_12 *server_hello)
void server_kex(Server_Key_Exchange *server_kex)
Callbacks & callbacks() const
const Ciphersuite & ciphersuite() const
void client_hello(Client_Hello_12 *client_hello)
virtual bool hide_unknown_users() const
virtual Group_Params choose_key_exchange_group(const std::vector< Group_Params > &supported_by_peer, const std::vector< Group_Params > &offered_by_peer) const
std::string get_string(size_t len_bytes, size_t min_bytes, size_t max_bytes)
std::vector< T > get_range(size_t len_bytes, size_t min_elems, size_t max_elems)
size_t remaining_bytes() const
CT::Mask< T > all_zeros(const T elem[], size_t len)
secure_vector< uint8_t > strip_leading_zeros(const uint8_t in[], size_t length)
void append_tls_length_value(std::vector< uint8_t, Alloc > &buf, const T *vals, size_t vals_size, size_t tag_size)
constexpr bool is_ecdh(const Group_Params group)
bool key_exchange_is_psk(Kex_Algo m)