// Copyright 2016 The BoringSSL Authors // // Licensed under the Apache License, Version 2.0 (the "License"); // you may not use this file except in compliance with the License. // You may obtain a copy of the License at // // https://www.apache.org/licenses/LICENSE-2.0 // // Unless required by applicable law or agreed to in writing, software // distributed under the License is distributed on an "AS IS" BASIS, // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. // See the License for the specific language governing permissions and // limitations under the License. #include #include #include #include #include #include #include #include #include #include #include #include #include #include "../crypto/bytestring/internal.h" #include "../crypto/internal.h" #include "internal.h" BSSL_NAMESPACE_BEGIN static const uint8_t kZeroes[EVP_MAX_MD_SIZE] = {0}; // Allow a minute of ticket age skew in either direction. This covers // transmission delays in ClientHello and NewSessionTicket, as well as // drift between client and server clock rate since the ticket was issued. // See RFC 8446, section 8.3. static const int32_t kMaxTicketAgeSkewSeconds = 60; static bool resolve_pake_secret(SSL_HANDSHAKE *hs) { uint8_t verifier_share[spake2plus::kShareSize]; uint8_t verifier_confirm[spake2plus::kConfirmSize]; uint8_t shared_secret[spake2plus::kSecretSize]; if (!hs->pake_verifier->ProcessProverShare(verifier_share, verifier_confirm, shared_secret, hs->pake_share->pake_message)) { OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR); ssl_send_alert(hs->ssl, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER); return false; } bssl::ScopedCBB cbb; if (!CBB_init(cbb.get(), sizeof(verifier_share) + sizeof(verifier_confirm)) || !CBB_add_bytes(cbb.get(), verifier_share, sizeof(verifier_share)) || !CBB_add_bytes(cbb.get(), verifier_confirm, sizeof(verifier_confirm)) || !CBBFinishArray(cbb.get(), &hs->pake_share_bytes)) { return false; } return tls13_advance_key_schedule( hs, MakeConstSpan(shared_secret, sizeof(shared_secret))); } static bool resolve_ecdhe_secret(SSL_HANDSHAKE *hs, const SSL_CLIENT_HELLO *client_hello) { SSL *const ssl = hs->ssl; const uint16_t group_id = hs->new_session->group_id; bool found_key_share; Span peer_key; uint8_t alert = SSL_AD_DECODE_ERROR; if (!ssl_ext_key_share_parse_clienthello(hs, &found_key_share, &peer_key, &alert, client_hello)) { ssl_send_alert(ssl, SSL3_AL_FATAL, alert); return false; } if (!found_key_share) { ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER); OPENSSL_PUT_ERROR(SSL, SSL_R_WRONG_CURVE); return false; } Array secret; SSL_HANDSHAKE_HINTS *const hints = hs->hints.get(); if (hints && !hs->hints_requested && hints->key_share_group_id == group_id && !hints->key_share_secret.empty()) { // Copy the key_share secret from hints. if (!hs->key_share_ciphertext.CopyFrom(hints->key_share_ciphertext) || !secret.CopyFrom(hints->key_share_secret)) { ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR); return false; } } else { ScopedCBB ciphertext; UniquePtr key_share = SSLKeyShare::Create(group_id); if (!key_share || // !CBB_init(ciphertext.get(), 32) || !key_share->Encap(ciphertext.get(), &secret, &alert, peer_key) || !CBBFinishArray(ciphertext.get(), &hs->key_share_ciphertext)) { ssl_send_alert(ssl, SSL3_AL_FATAL, alert); return false; } if (hints && hs->hints_requested) { hints->key_share_group_id = group_id; if (!hints->key_share_ciphertext.CopyFrom(hs->key_share_ciphertext) || !hints->key_share_secret.CopyFrom(secret)) { ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR); return false; } } } return tls13_advance_key_schedule(hs, secret); } static int ssl_ext_supported_versions_add_serverhello(SSL_HANDSHAKE *hs, CBB *out) { CBB contents; if (!CBB_add_u16(out, TLSEXT_TYPE_supported_versions) || // !CBB_add_u16_length_prefixed(out, &contents) || // !CBB_add_u16(&contents, hs->ssl->s3->version) || // !CBB_flush(out)) { return 0; } return 1; } static const SSL_CIPHER *choose_tls13_cipher( const SSL *ssl, const SSL_CLIENT_HELLO *client_hello) { CBS cipher_suites; CBS_init(&cipher_suites, client_hello->cipher_suites, client_hello->cipher_suites_len); const uint16_t version = ssl_protocol_version(ssl); return ssl_choose_tls13_cipher(cipher_suites, ssl->config->aes_hw_override ? ssl->config->aes_hw_override_value : EVP_has_aes_hardware(), version, ssl->config->compliance_policy); } static bool add_new_session_tickets(SSL_HANDSHAKE *hs, bool *out_sent_tickets) { SSL *const ssl = hs->ssl; if ( // If the client doesn't accept resumption with PSK_DHE_KE, don't send a // session ticket. !hs->accept_psk_mode || // We only implement stateless resumption in TLS 1.3, so skip sending // tickets if disabled. (SSL_get_options(ssl) & SSL_OP_NO_TICKET) || // Don't send tickets for PAKE connections. We don't support resumption // with PAKEs. hs->pake_verifier != nullptr) { *out_sent_tickets = false; return true; } // Rebase the session timestamp so that it is measured from ticket // issuance. ssl_session_rebase_time(ssl, hs->new_session.get()); assert(ssl->session_ctx->num_tickets <= kMaxTickets); bool sent_tickets = false; for (size_t i = 0; i < ssl->session_ctx->num_tickets; i++) { UniquePtr session( SSL_SESSION_dup(hs->new_session.get(), SSL_SESSION_INCLUDE_NONAUTH)); if (!session) { return false; } if (!RAND_bytes((uint8_t *)&session->ticket_age_add, 4)) { return false; } session->ticket_age_add_valid = true; // TODO(crbug.com/381113363): Remove the SSL_is_dtls check once we support // 0-RTT for DTLS 1.3. bool enable_early_data = ssl->enable_early_data && (!SSL_is_quic(ssl) || !ssl->config->quic_early_data_context.empty()) && !SSL_is_dtls(ssl); if (enable_early_data) { // QUIC does not use the max_early_data_size parameter and always sets it // to a fixed value. See RFC 9001, section 4.6.1. session->ticket_max_early_data = SSL_is_quic(ssl) ? 0xffffffff : kMaxEarlyDataAccepted; } session->is_resumable_across_names = ssl->resumption_across_names_enabled; static_assert(kMaxTickets < 256, "Too many tickets"); assert(i < 256); uint8_t nonce[] = {static_cast(i)}; ScopedCBB cbb; CBB body, nonce_cbb, ticket, extensions; if (!ssl->method->init_message(ssl, cbb.get(), &body, SSL3_MT_NEW_SESSION_TICKET) || !CBB_add_u32(&body, session->timeout) || !CBB_add_u32(&body, session->ticket_age_add) || !CBB_add_u8_length_prefixed(&body, &nonce_cbb) || !CBB_add_bytes(&nonce_cbb, nonce, sizeof(nonce)) || !tls13_derive_session_psk(session.get(), nonce, SSL_is_dtls(ssl)) || !CBB_add_u16_length_prefixed(&body, &ticket) || !ssl_encrypt_ticket(hs, &ticket, session.get())) { return false; } if (CBB_len(&ticket) == 0) { // The caller decided not to encrypt a ticket. Skip the message. continue; } if (!CBB_add_u16_length_prefixed(&body, &extensions)) { return false; } if (enable_early_data) { CBB early_data; if (!CBB_add_u16(&extensions, TLSEXT_TYPE_early_data) || !CBB_add_u16_length_prefixed(&extensions, &early_data) || !CBB_add_u32(&early_data, session->ticket_max_early_data) || !CBB_flush(&extensions)) { return false; } } SSLFlags flags = 0; if (session->is_resumable_across_names) { flags |= kSSLFlagResumptionAcrossNames; } if (!ssl_add_flags_extension(&extensions, flags)) { return false; } // Add a fake extension. See RFC 8701. if (!CBB_add_u16(&extensions, ssl_get_grease_value(hs, ssl_grease_ticket_extension)) || !CBB_add_u16(&extensions, 0 /* empty */)) { return false; } if (!ssl_add_message_cbb(ssl, cbb.get())) { return false; } sent_tickets = true; } *out_sent_tickets = sent_tickets; return true; } bool ssl_check_tls13_credential_ignoring_issuer( SSL_HANDSHAKE *hs, Span allowed_cert_types, const SSLCredential *cred, uint16_t *out_sigalg) { assert(!allowed_cert_types.empty()); const auto is_cert_type_allowed = [&](uint8_t cert_type) { return std::find(allowed_cert_types.begin(), allowed_cert_types.end(), cert_type) != allowed_cert_types.end(); }; switch (cred->type) { case SSLCredentialType::kDelegated: // Check that the peer supports the signature over the delegated // credential. if (std::find(hs->peer_sigalgs.begin(), hs->peer_sigalgs.end(), cred->dc_algorithm) == hs->peer_sigalgs.end()) { OPENSSL_PUT_ERROR(SSL, SSL_R_NO_COMMON_SIGNATURE_ALGORITHMS); return false; } [[fallthrough]]; case SSLCredentialType::kX509: case SSLCredentialType::kRawPublicKey: if (!is_cert_type_allowed( *ssl_credential_type_to_cert_type(cred->type))) { OPENSSL_PUT_ERROR(SSL, SSL_R_UNKNOWN_CERTIFICATE_TYPE); return false; } break; default: OPENSSL_PUT_ERROR(SSL, SSL_R_UNKNOWN_CERTIFICATE_TYPE); return false; } // If we reach here then the credential requires a signature. If |cred| is a // delegated credential, this also checks that the peer supports delegated // credentials and matched |dc_cert_verify_algorithm|. return tls1_choose_signature_algorithm(hs, cred, out_sigalg); } static bool check_signature_credential(SSL_HANDSHAKE *hs, Span allowed_cert_types, const SSLCredential *cred, uint16_t *out_sigalg) { return ssl_check_tls13_credential_ignoring_issuer(hs, allowed_cert_types, cred, out_sigalg) && // Use this credential if it either matches a requested issuer, // or does not require issuer matching. ssl_credential_matches_requested_issuers(hs, cred); } static bool check_pake_credential(SSL_HANDSHAKE *hs, const SSLCredential *cred) { assert(cred->type == SSLCredentialType::kSPAKE2PlusV1Server); // Look for a client PAKE share that matches |cred|. if (hs->pake_share == nullptr || hs->pake_share->named_pake != SSL_PAKE_SPAKE2PLUSV1 || hs->pake_share->client_identity != Span(cred->client_identity) || hs->pake_share->server_identity != Span(cred->server_identity)) { OPENSSL_PUT_ERROR(SSL, SSL_R_PEER_PAKE_MISMATCH); return false; } return true; } static bool check_psk_credential(SSL_HANDSHAKE *hs, const SSLCredential *cred, const std::optional &psks) { assert(cred->type == SSLCredentialType::kPreSharedKey); SSL *const ssl = hs->ssl; if (!psks) { OPENSSL_PUT_ERROR(SSL, SSL_R_MISSING_EXTENSION); return false; } if (!hs->accept_psk_mode) { OPENSSL_PUT_ERROR(SSL, SSL_R_NO_SUPPORTED_PSK_MODE); return false; } // Look for a matching PSK. const EVP_MD *md = ssl_get_handshake_digest(ssl_protocol_version(ssl), hs->new_cipher); SSLOfferedPSKs copy = *psks; for (;;) { std::optional psk = copy.Next(); if (!psk) { OPENSSL_PUT_ERROR(SSL, SSL_R_PSK_IDENTITY_NOT_FOUND); return false; } if (tls13_compare_imported_psk_identity(psk->identity, cred, ssl->s3->version, md)) { return true; } } } static enum ssl_hs_wait_t do_select_parameters(SSL_HANDSHAKE *hs) { // At this point, most ClientHello extensions have already been processed by // the common handshake logic. Resolve the remaining non-resumption // parameters. First, parse out another copy of the ClientHello and important // extensions. SSL *const ssl = hs->ssl; SSLMessage msg; SSL_CLIENT_HELLO client_hello; if (!hs->GetClientHello(&msg, &client_hello)) { return ssl_hs_error; } std::optional psks; CBS psk_ext; uint8_t alert = SSL_AD_DECODE_ERROR; if (ssl_client_hello_get_extension(&client_hello, &psk_ext, TLSEXT_TYPE_pre_shared_key)) { psks = ssl_ext_pre_shared_key_parse_clienthello(hs, &alert, &client_hello, &psk_ext); if (!psks) { ssl_send_alert(ssl, SSL3_AL_FATAL, alert); return ssl_hs_error; } } if (SSL_is_quic(ssl) && client_hello.session_id_len > 0) { OPENSSL_PUT_ERROR(SSL, SSL_R_UNEXPECTED_COMPATIBILITY_MODE); ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER); return ssl_hs_error; } // DTLS 1.3 disables compatibility mode, and even if the client advertised a // session ID (for resumption in DTLS 1.2), the server "MUST NOT echo the // 'legacy_session_id' value from the client" (RFC 9147, section 5) as it // would in a TLS 1.3 handshake. if (!SSL_is_dtls(ssl)) { hs->session_id.CopyFrom( Span(client_hello.session_id, client_hello.session_id_len)); } // Negotiate the cipher suite. This must happen before negotiating PSKs. hs->new_cipher = choose_tls13_cipher(ssl, &client_hello); if (hs->new_cipher == nullptr) { OPENSSL_PUT_ERROR(SSL, SSL_R_NO_SHARED_CIPHER); ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_HANDSHAKE_FAILURE); return ssl_hs_error; } // Select the credential to use. Array creds; if (!ssl_get_full_credential_list(hs, &creds)) { return ssl_hs_error; } if (creds.empty()) { OPENSSL_PUT_ERROR(SSL, SSL_R_NO_CERTIFICATE_SET); ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR); return ssl_hs_error; } std::optional> allowed_cert_types = ssl_get_allowed_server_cert_types(hs, &client_hello, &alert); if (!allowed_cert_types.has_value()) { ssl_send_alert(ssl, SSL3_AL_FATAL, alert); return ssl_hs_error; } for (SSLCredential *cred : creds) { ERR_clear_error(); if (cred->type == SSLCredentialType::kSPAKE2PlusV1Server) { if (check_pake_credential(hs, cred)) { hs->credential = UpRef(cred); hs->pake_verifier = MakeUnique(); if (hs->pake_verifier == nullptr || !hs->pake_verifier->Init(cred->pake_context, cred->client_identity, cred->server_identity, cred->password_verifier_w0, cred->registration_record)) { ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR); return ssl_hs_error; } break; } } else if (cred->type == SSLCredentialType::kPreSharedKey) { if (check_psk_credential(hs, cred, psks)) { const EVP_MD *md = ssl_get_handshake_digest(ssl_protocol_version(ssl), hs->new_cipher); std::optional imported = tls13_derive_imported_psk(hs, cred, ssl->s3->version, md); if (!imported) { return ssl_hs_error; } hs->credential = UpRef(cred); hs->pre_shared_key = MakeUnique(*std::move(imported)); if (hs->pre_shared_key == nullptr) { return ssl_hs_error; } break; } } else { uint16_t sigalg; if (check_signature_credential(hs, *allowed_cert_types, cred, &sigalg)) { hs->credential = UpRef(cred); hs->signature_algorithm = sigalg; break; } } } if (hs->credential == nullptr) { // The error from the last attempt is in the error queue. assert(ERR_peek_error() != 0); ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_HANDSHAKE_FAILURE); return ssl_hs_error; } // HTTP/2 negotiation depends on the cipher suite, so ALPN negotiation was // deferred. Complete it now. if (!ssl_negotiate_alpn(hs, &alert, &client_hello)) { ssl_send_alert(ssl, SSL3_AL_FATAL, alert); return ssl_hs_error; } // The PRF hash is now known. if (!hs->transcript.InitHash(ssl_protocol_version(ssl), hs->new_cipher)) { return ssl_hs_error; } hs->tls13_state = state13_select_session; return ssl_hs_ok; } static enum ssl_ticket_aead_result_t select_session( SSL_HANDSHAKE *hs, uint8_t *out_alert, UniquePtr *out_session, int32_t *out_ticket_age_skew, bool *out_offered_ticket, const SSLMessage &msg, const SSL_CLIENT_HELLO *client_hello) { SSL *const ssl = hs->ssl; *out_session = nullptr; CBS pre_shared_key; *out_offered_ticket = ssl_client_hello_get_extension( client_hello, &pre_shared_key, TLSEXT_TYPE_pre_shared_key); if (!*out_offered_ticket) { return ssl_ticket_aead_ignore_ticket; } // Per RFC 8446, section 4.2.9, servers MUST abort the handshake if the client // sends pre_shared_key without psk_key_exchange_modes. CBS unused; if (!ssl_client_hello_get_extension(client_hello, &unused, TLSEXT_TYPE_psk_key_exchange_modes)) { *out_alert = SSL_AD_MISSING_EXTENSION; OPENSSL_PUT_ERROR(SSL, SSL_R_MISSING_EXTENSION); return ssl_ticket_aead_error; } std::optional psks = ssl_ext_pre_shared_key_parse_clienthello( hs, out_alert, client_hello, &pre_shared_key); if (!psks) { return ssl_ticket_aead_error; } // If the peer did not offer psk_dhe, ignore the resumption. if (!hs->accept_psk_mode) { return ssl_ticket_aead_ignore_ticket; } // We do not currently support resumption with PAKEs. if (hs->credential != nullptr && hs->credential->type == SSLCredentialType::kSPAKE2PlusV1Server) { return ssl_ticket_aead_ignore_ticket; } // We only consider the first PSK for session resumption. std::optional psk = psks->Next(); if (!psk) { OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR); return ssl_ticket_aead_error; } // Ignore whether the caller asked for TLS 1.2 ticket renewal. TLS 1.3 session // tickets are renewed separately as part of the NewSessionTicket. Also save // the ticket so we can find the PSK again on the second ClientHello. bool unused_renew; UniquePtr session; enum ssl_ticket_aead_result_t ret = ssl_process_ticket(hs, &session, &unused_renew, psk->identity, /*session_id=*/{}, /*save_ticket=*/true); switch (ret) { case ssl_ticket_aead_success: break; case ssl_ticket_aead_error: *out_alert = SSL_AD_INTERNAL_ERROR; return ret; default: return ret; } if (!ssl_session_is_resumable(hs, session.get()) || // Historically, some TLS 1.3 tickets were missing ticket_age_add. !session->ticket_age_add_valid) { return ssl_ticket_aead_ignore_ticket; } // Recover the client ticket age and convert to seconds. uint32_t client_ticket_age = psk->obfuscated_ticket_age - session->ticket_age_add; client_ticket_age /= 1000; OPENSSL_timeval now = ssl_ctx_get_current_time(ssl->ctx.get()); // Compute the server ticket age in seconds. assert(now.tv_sec >= session->time); uint64_t server_ticket_age = now.tv_sec - session->time; // To avoid overflowing |hs->ticket_age_skew|, we will not resume // 68-year-old sessions. if (server_ticket_age > INT32_MAX) { return ssl_ticket_aead_ignore_ticket; } *out_ticket_age_skew = static_cast(client_ticket_age) - static_cast(server_ticket_age); *out_session = std::move(session); return ssl_ticket_aead_success; } static bool quic_ticket_compatible(const SSL_SESSION *session, const SSL_CONFIG *config) { if (!session->is_quic) { return true; } if (session->quic_early_data_context.empty() || config->quic_early_data_context.size() != session->quic_early_data_context.size() || CRYPTO_memcmp(config->quic_early_data_context.data(), session->quic_early_data_context.data(), session->quic_early_data_context.size()) != 0) { return false; } return true; } static bool using_certificate(const SSL_HANDSHAKE *hs) { return !hs->pre_shared_key && !hs->pake_verifier; } static enum ssl_hs_wait_t do_select_session(SSL_HANDSHAKE *hs) { SSL *const ssl = hs->ssl; SSLMessage msg; SSL_CLIENT_HELLO client_hello; if (!hs->GetClientHello(&msg, &client_hello)) { return ssl_hs_error; } uint8_t alert = SSL_AD_DECODE_ERROR; UniquePtr session; bool offered_ticket = false; switch (select_session(hs, &alert, &session, &ssl->s3->ticket_age_skew, &offered_ticket, msg, &client_hello)) { case ssl_ticket_aead_ignore_ticket: assert(!session); if (!ssl_get_new_session(hs)) { ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR); return ssl_hs_error; } break; case ssl_ticket_aead_success: // Carry over authentication information from the previous handshake into // a fresh session. hs->new_session = SSL_SESSION_dup(session.get(), SSL_SESSION_DUP_AUTH_ONLY); if (hs->new_session == nullptr) { ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR); return ssl_hs_error; } // Resumption incorporates fresh key material, so refresh the timeout. ssl_session_renew_timeout(ssl, hs->new_session.get(), ssl->session_ctx->session_psk_dhe_timeout); ssl->s3->session_reused = true; hs->pre_shared_key = MakeUnique(UpRef(session)); if (hs->pre_shared_key == nullptr) { return ssl_hs_error; } break; case ssl_ticket_aead_error: ssl_send_alert(ssl, SSL3_AL_FATAL, alert); return ssl_hs_error; case ssl_ticket_aead_retry: hs->tls13_state = state13_select_session; return ssl_hs_pending_ticket; } hs->can_release_private_key = !using_certificate(hs); // Negotiate ALPS now, after ALPN is negotiated and |hs->new_session| is // initialized. if (!ssl_negotiate_alps(hs, &alert, &client_hello)) { ssl_send_alert(ssl, SSL3_AL_FATAL, alert); return ssl_hs_error; } if (using_certificate(hs)) { // Determine whether to request a client certificate. hs->cert_request = !!(hs->config->verify_mode & SSL_VERIFY_PEER); if (!ssl_negotiate_client_certificate_type(hs, &alert, &client_hello)) { ssl_send_alert(ssl, SSL3_AL_FATAL, alert); return ssl_hs_error; } } // Record connection properties in the new session. hs->new_session->cipher = hs->new_cipher; // If using key shares, resolve the supported group and determine if we need // HelloRetryRequest. bool need_hrr = false; if (hs->pake_verifier == nullptr) { if (!tls1_get_shared_group(hs, &hs->new_session->group_id)) { OPENSSL_PUT_ERROR(SSL, SSL_R_NO_SHARED_GROUP); ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_HANDSHAKE_FAILURE); return ssl_hs_error; } bool found_key_share; if (!ssl_ext_key_share_parse_clienthello(hs, &found_key_share, /*out_key_share=*/nullptr, &alert, &client_hello)) { ssl_send_alert(ssl, SSL3_AL_FATAL, alert); return ssl_hs_error; } need_hrr = !found_key_share; } // Determine if we're negotiating 0-RTT. if (!ssl->enable_early_data) { ssl->s3->early_data_reason = ssl_early_data_disabled; } else if (!offered_ticket) { ssl->s3->early_data_reason = ssl_early_data_no_session_offered; } else if (!session) { ssl->s3->early_data_reason = ssl_early_data_session_not_resumed; } else if (session->ticket_max_early_data == 0) { ssl->s3->early_data_reason = ssl_early_data_unsupported_for_session; } else if (!hs->early_data_offered) { ssl->s3->early_data_reason = ssl_early_data_peer_declined; } else if (hs->channel_id_negotiated) { // Channel ID is incompatible with 0-RTT. ssl->s3->early_data_reason = ssl_early_data_channel_id; } else if (Span(ssl->s3->alpn_selected) != session->early_alpn) { // The negotiated ALPN must match the one in the ticket. ssl->s3->early_data_reason = ssl_early_data_alpn_mismatch; } else if (hs->new_session->has_application_settings != session->has_application_settings || Span(hs->new_session->local_application_settings) != session->local_application_settings) { ssl->s3->early_data_reason = ssl_early_data_alps_mismatch; } else if (ssl->s3->ticket_age_skew < -kMaxTicketAgeSkewSeconds || kMaxTicketAgeSkewSeconds < ssl->s3->ticket_age_skew) { ssl->s3->early_data_reason = ssl_early_data_ticket_age_skew; } else if (!quic_ticket_compatible(session.get(), hs->config)) { ssl->s3->early_data_reason = ssl_early_data_quic_parameter_mismatch; } else if (need_hrr) { ssl->s3->early_data_reason = ssl_early_data_hello_retry_request; } else { // |ssl_session_is_resumable| forbids cross-cipher resumptions even if the // PRF hashes match. assert(hs->new_cipher == session->cipher); ssl->s3->early_data_reason = ssl_early_data_accepted; ssl->s3->early_data_accepted = true; } // Store the ALPN and ALPS values in the session for 0-RTT. Note the peer // applications settings are not generally known until client // EncryptedExtensions. if (!hs->new_session->early_alpn.CopyFrom(ssl->s3->alpn_selected)) { ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR); return ssl_hs_error; } // The peer applications settings are usually received later, in // EncryptedExtensions. But, in 0-RTT handshakes, we carry over the // values from |session|. Do this now, before |session| is discarded. if (ssl->s3->early_data_accepted && hs->new_session->has_application_settings && !hs->new_session->peer_application_settings.CopyFrom( session->peer_application_settings)) { ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR); return ssl_hs_error; } // Copy the QUIC early data context to the session. if (ssl->enable_early_data && SSL_is_quic(ssl)) { if (!hs->new_session->quic_early_data_context.CopyFrom( hs->config->quic_early_data_context)) { ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR); return ssl_hs_error; } } if (ssl->ctx->dos_protection_cb != nullptr && ssl->ctx->dos_protection_cb(&client_hello) == 0) { // Connection rejected for DOS reasons. OPENSSL_PUT_ERROR(SSL, SSL_R_CONNECTION_REJECTED); ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR); return ssl_hs_error; } if (hs->pre_shared_key && !ssl_verify_psk_binder(hs, &alert, *hs->pre_shared_key, client_hello)) { ssl_send_alert(ssl, SSL3_AL_FATAL, alert); return ssl_hs_error; } size_t hash_len = EVP_MD_size( ssl_get_handshake_digest(ssl_protocol_version(ssl), hs->new_cipher)); // Set up the key schedule and incorporate the PSK into the running secret. Span psk = hs->pre_shared_key ? ssl_pre_shared_key_secret(*hs->pre_shared_key) : Span(kZeroes, hash_len); if (!tls13_init_key_schedule(hs, psk) || // !ssl_hash_message(hs, msg)) { return ssl_hs_error; } if (ssl->s3->early_data_accepted) { if (!tls13_derive_early_secret(hs)) { return ssl_hs_error; } } else if (hs->early_data_offered) { ssl->s3->skip_early_data = true; } if (need_hrr) { ssl->method->next_message(ssl); if (!hs->transcript.UpdateForHelloRetryRequest()) { return ssl_hs_error; } hs->tls13_state = state13_send_hello_retry_request; return ssl_hs_ok; } if (hs->pake_verifier) { assert(!ssl->s3->session_reused); // Revealing the PAKE share (notably confirmV) allows the client to confirm // one PAKE guess, so we must deduct from the brute force limit. if (!hs->credential->ClaimPAKEAttempt()) { OPENSSL_PUT_ERROR(SSL, SSL_R_PAKE_EXHAUSTED); ssl_send_alert(hs->ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR); return ssl_hs_error; } if (!resolve_pake_secret(hs)) { return ssl_hs_error; } } else { if (!resolve_ecdhe_secret(hs, &client_hello)) { return ssl_hs_error; } } ssl->method->next_message(ssl); hs->ech_client_hello_buf.Reset(); hs->tls13_state = state13_send_server_hello; return ssl_hs_ok; } static enum ssl_hs_wait_t do_send_hello_retry_request(SSL_HANDSHAKE *hs) { SSL *const ssl = hs->ssl; if (hs->hints_requested) { return ssl_hs_hints_ready; } // Although a server could HelloRetryRequest with PAKEs to request a cookie, // we never do so. assert(hs->pake_verifier == nullptr); ScopedCBB cbb; CBB body, session_id, extensions; if (!ssl->method->init_message(ssl, cbb.get(), &body, SSL3_MT_SERVER_HELLO) || !CBB_add_u16(&body, SSL_is_dtls(ssl) ? DTLS1_2_VERSION : TLS1_2_VERSION) || !CBB_add_bytes(&body, kHelloRetryRequest, SSL3_RANDOM_SIZE) || !CBB_add_u8_length_prefixed(&body, &session_id) || !CBB_add_bytes(&session_id, hs->session_id.data(), hs->session_id.size()) || !CBB_add_u16(&body, SSL_CIPHER_get_protocol_id(hs->new_cipher)) || !CBB_add_u8(&body, 0 /* no compression */) || !CBB_add_u16_length_prefixed(&body, &extensions) || !CBB_add_u16(&extensions, TLSEXT_TYPE_supported_versions) || !CBB_add_u16(&extensions, 2 /* length */) || !CBB_add_u16(&extensions, ssl->s3->version) || !CBB_add_u16(&extensions, TLSEXT_TYPE_key_share) || !CBB_add_u16(&extensions, 2 /* length */) || !CBB_add_u16(&extensions, hs->new_session->group_id)) { return ssl_hs_error; } if (hs->ech_is_inner) { // Fill a placeholder for the ECH confirmation value. if (!CBB_add_u16(&extensions, TLSEXT_TYPE_encrypted_client_hello) || !CBB_add_u16(&extensions, ECH_CONFIRMATION_SIGNAL_LEN) || !CBB_add_zeros(&extensions, ECH_CONFIRMATION_SIGNAL_LEN)) { return ssl_hs_error; } } Array hrr; if (!ssl->method->finish_message(ssl, cbb.get(), &hrr)) { return ssl_hs_error; } if (hs->ech_is_inner) { // Now that the message is encoded, fill in the whole value. size_t offset = hrr.size() - ECH_CONFIRMATION_SIGNAL_LEN; if (!ssl_ech_accept_confirmation( hs, Span(hrr).last(), ssl->s3->client_random, hs->transcript, /*is_hrr=*/true, hrr, offset)) { return ssl_hs_error; } } if (!ssl->method->add_message(ssl, std::move(hrr)) || !ssl->method->add_change_cipher_spec(ssl)) { return ssl_hs_error; } ssl->s3->used_hello_retry_request = true; hs->tls13_state = state13_read_second_client_hello; return ssl_hs_flush; } static enum ssl_hs_wait_t do_read_second_client_hello(SSL_HANDSHAKE *hs) { SSL *const ssl = hs->ssl; SSLMessage msg; if (!ssl->method->get_message(ssl, &msg)) { return ssl_hs_read_message; } if (!ssl_check_message_type(ssl, msg, SSL3_MT_CLIENT_HELLO)) { return ssl_hs_error; } SSL_CLIENT_HELLO client_hello; if (!SSL_parse_client_hello(ssl, &client_hello, CBS_data(&msg.body), CBS_len(&msg.body))) { ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR); return ssl_hs_error; } if (ssl->s3->ech_status == ssl_ech_accepted) { // If we previously accepted the ClientHelloInner, the second ClientHello // must contain an outer encrypted_client_hello extension. CBS ech_body; if (!ssl_client_hello_get_extension(&client_hello, &ech_body, TLSEXT_TYPE_encrypted_client_hello)) { OPENSSL_PUT_ERROR(SSL, SSL_R_MISSING_EXTENSION); ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_MISSING_EXTENSION); return ssl_hs_error; } uint16_t kdf_id, aead_id; uint8_t type, config_id; CBS enc, payload; if (!CBS_get_u8(&ech_body, &type) || // type != ECH_CLIENT_OUTER || // !CBS_get_u16(&ech_body, &kdf_id) || // !CBS_get_u16(&ech_body, &aead_id) || !CBS_get_u8(&ech_body, &config_id) || !CBS_get_u16_length_prefixed(&ech_body, &enc) || !CBS_get_u16_length_prefixed(&ech_body, &payload) || CBS_len(&ech_body) != 0) { OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR); ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR); return ssl_hs_error; } if (kdf_id != EVP_HPKE_KDF_id(EVP_HPKE_CTX_kdf(hs->ech_hpke_ctx.get())) || aead_id != EVP_HPKE_AEAD_id(EVP_HPKE_CTX_aead(hs->ech_hpke_ctx.get())) || config_id != hs->ech_config_id || CBS_len(&enc) > 0) { OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR); ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER); return ssl_hs_error; } // Decrypt the payload with the HPKE context from the first ClientHello. uint8_t alert = SSL_AD_DECODE_ERROR; bool unused; if (!ssl_client_hello_decrypt(hs, &alert, &unused, &hs->ech_client_hello_buf, &client_hello, payload)) { // Decryption failure is fatal in the second ClientHello. OPENSSL_PUT_ERROR(SSL, SSL_R_DECRYPTION_FAILED); ssl_send_alert(ssl, SSL3_AL_FATAL, alert); return ssl_hs_error; } // Reparse |client_hello| from the buffer owned by |hs|. if (!hs->GetClientHello(&msg, &client_hello)) { OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR); return ssl_hs_error; } } // We perform all our negotiation based on the first ClientHello (for // consistency with what |select_certificate_cb| observed), which is in the // transcript, so we can ignore most of this second one. // // We do, however, check the second PSK binder. This covers the client key // share, in case we ever send half-RTT data (we currently do not). It is also // a tricky computation, so we enforce the peer handled it correctly. It is // also necessary to search the PSK list from the second ClientHello because // PSK indices may have changed (RFC 8446 section 4.1.4). if (hs->pre_shared_key) { uint8_t alert = SSL_AD_DECODE_ERROR; if (!ssl_verify_psk_binder(hs, &alert, *hs->pre_shared_key, client_hello)) { ssl_send_alert(ssl, SSL3_AL_FATAL, alert); return ssl_hs_error; } } // Although a server could HelloRetryRequest with PAKEs to request a cookie, // we never do so. assert(hs->pake_verifier == nullptr); if (!resolve_ecdhe_secret(hs, &client_hello)) { return ssl_hs_error; } if (!ssl_hash_message(hs, msg)) { return ssl_hs_error; } // ClientHello should be the end of the flight. if (ssl->method->has_unprocessed_handshake_data(ssl)) { ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_UNEXPECTED_MESSAGE); OPENSSL_PUT_ERROR(SSL, SSL_R_EXCESS_HANDSHAKE_DATA); return ssl_hs_error; } ssl->method->next_message(ssl); hs->ech_client_hello_buf.Reset(); hs->tls13_state = state13_send_server_hello; return ssl_hs_ok; } static enum ssl_hs_wait_t do_send_server_hello(SSL_HANDSHAKE *hs) { SSL *const ssl = hs->ssl; Span random(ssl->s3->server_random); SSL_HANDSHAKE_HINTS *const hints = hs->hints.get(); if (hints && !hs->hints_requested && hints->server_random_tls13.size() == random.size()) { OPENSSL_memcpy(random.data(), hints->server_random_tls13.data(), random.size()); } else { RAND_bytes(random.data(), random.size()); if (hints && hs->hints_requested && !hints->server_random_tls13.CopyFrom(random)) { return ssl_hs_error; } } Array server_hello; ScopedCBB cbb; CBB body, extensions, session_id; if (!ssl->method->init_message(ssl, cbb.get(), &body, SSL3_MT_SERVER_HELLO) || !CBB_add_u16(&body, SSL_is_dtls(ssl) ? DTLS1_2_VERSION : TLS1_2_VERSION) || !CBB_add_bytes(&body, ssl->s3->server_random, sizeof(ssl->s3->server_random)) || !CBB_add_u8_length_prefixed(&body, &session_id) || !CBB_add_bytes(&session_id, hs->session_id.data(), hs->session_id.size()) || !CBB_add_u16(&body, SSL_CIPHER_get_protocol_id(hs->new_cipher)) || !CBB_add_u8(&body, 0) || !CBB_add_u16_length_prefixed(&body, &extensions) || !ssl_ext_pre_shared_key_add_serverhello(hs, &extensions) || !ssl_ext_pake_add_serverhello(hs, &extensions) || !ssl_ext_key_share_add_serverhello(hs, &extensions) || !ssl_ext_supported_versions_add_serverhello(hs, &extensions) || !ssl->method->finish_message(ssl, cbb.get(), &server_hello)) { return ssl_hs_error; } assert(ssl->s3->ech_status != ssl_ech_accepted || hs->ech_is_inner); if (hs->ech_is_inner) { // Fill in the ECH confirmation signal. const size_t offset = ssl_ech_confirmation_signal_hello_offset(ssl); auto random_suffix = random.last(); if (!ssl_ech_accept_confirmation(hs, random_suffix, ssl->s3->client_random, hs->transcript, /*is_hrr=*/false, server_hello, offset)) { return ssl_hs_error; } // Update |server_hello|. auto server_hello_out = Span(server_hello).subspan(offset).first(); OPENSSL_memcpy(server_hello_out.data(), random_suffix.data(), ECH_CONFIRMATION_SIGNAL_LEN); } if (!ssl->method->add_message(ssl, std::move(server_hello))) { return ssl_hs_error; } hs->key_share_ciphertext.Reset(); // No longer needed. if (!ssl->s3->used_hello_retry_request && !ssl->method->add_change_cipher_spec(ssl)) { return ssl_hs_error; } // Derive and enable the handshake traffic secrets. if (!tls13_derive_handshake_secrets(hs) || !tls13_set_traffic_key(ssl, ssl_encryption_handshake, evp_aead_seal, hs->new_session.get(), hs->server_handshake_secret)) { return ssl_hs_error; } // Send EncryptedExtensions. if (!ssl->method->init_message(ssl, cbb.get(), &body, SSL3_MT_ENCRYPTED_EXTENSIONS) || !ssl_add_serverhello_tlsext(hs, &body) || !ssl_add_message_cbb(ssl, cbb.get())) { return ssl_hs_error; } // Send a CertificateRequest, if necessary. if (hs->cert_request) { CBB cert_request_extensions, sigalg_contents, sigalgs_cbb; if (!ssl->method->init_message(ssl, cbb.get(), &body, SSL3_MT_CERTIFICATE_REQUEST) || !CBB_add_u8(&body, 0 /* no certificate_request_context. */) || !CBB_add_u16_length_prefixed(&body, &cert_request_extensions) || !CBB_add_u16(&cert_request_extensions, TLSEXT_TYPE_signature_algorithms) || !CBB_add_u16_length_prefixed(&cert_request_extensions, &sigalg_contents) || !CBB_add_u16_length_prefixed(&sigalg_contents, &sigalgs_cbb) || !tls12_add_verify_sigalgs(hs, &sigalgs_cbb)) { return ssl_hs_error; } if (ssl_has_client_CAs(hs->config)) { CBB ca_contents; if (!CBB_add_u16(&cert_request_extensions, TLSEXT_TYPE_certificate_authorities) || !CBB_add_u16_length_prefixed(&cert_request_extensions, &ca_contents) || !ssl_add_client_CA_list(hs, &ca_contents) || !CBB_flush(&cert_request_extensions)) { return ssl_hs_error; } } if (!ssl_add_message_cbb(ssl, cbb.get())) { return ssl_hs_error; } } // Send the server Certificate message, if necessary. if (using_certificate(hs)) { if (!tls13_add_certificate(hs)) { return ssl_hs_error; } hs->tls13_state = state13_send_server_certificate_verify; return ssl_hs_ok; } hs->tls13_state = state13_send_server_finished; return ssl_hs_ok; } static enum ssl_hs_wait_t do_send_server_certificate_verify(SSL_HANDSHAKE *hs) { switch (tls13_add_certificate_verify(hs)) { case ssl_private_key_success: hs->tls13_state = state13_send_server_finished; return ssl_hs_ok; case ssl_private_key_retry: hs->tls13_state = state13_send_server_certificate_verify; return ssl_hs_private_key_operation; case ssl_private_key_failure: return ssl_hs_error; } assert(0); return ssl_hs_error; } static enum ssl_hs_wait_t do_send_server_finished(SSL_HANDSHAKE *hs) { SSL *const ssl = hs->ssl; if (hs->hints_requested) { return ssl_hs_hints_ready; } hs->can_release_private_key = true; if (!tls13_add_finished(hs) || // Update the secret to the master secret and derive traffic keys. !tls13_advance_key_schedule(hs, Span(kZeroes, hs->transcript.DigestLen())) || !tls13_derive_application_secrets(hs) || !tls13_set_traffic_key(ssl, ssl_encryption_application, evp_aead_seal, hs->new_session.get(), hs->server_traffic_secret_0)) { return ssl_hs_error; } hs->tls13_state = state13_send_half_rtt_ticket; return hs->handback ? ssl_hs_handback : ssl_hs_ok; } static enum ssl_hs_wait_t do_send_half_rtt_ticket(SSL_HANDSHAKE *hs) { SSL *const ssl = hs->ssl; if (ssl->s3->early_data_accepted) { // If accepting 0-RTT, we send tickets half-RTT. This gets the tickets on // the wire sooner and also avoids triggering a write on |SSL_read| when // processing the client Finished. This requires computing the client // Finished early. See RFC 8446, section 4.6.1. static const uint8_t kEndOfEarlyData[4] = {SSL3_MT_END_OF_EARLY_DATA, 0, 0, 0}; if (!SSL_is_quic(ssl) && !hs->transcript.Update(kEndOfEarlyData)) { OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR); return ssl_hs_error; } size_t finished_len; hs->expected_client_finished.Resize(hs->transcript.DigestLen()); if (!tls13_finished_mac(hs, hs->expected_client_finished.data(), &finished_len, false /* client */)) { return ssl_hs_error; } if (finished_len != hs->expected_client_finished.size()) { OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR); return ssl_hs_error; } // Feed the predicted Finished into the transcript. This allows us to derive // the resumption secret early and send half-RTT tickets. // // TODO(crbug.com/381113363): Don't use half-RTT tickets with DTLS 1.3. // TODO(crbug.com/376939532): Perhaps don't use half-RTT tickets at all. assert(!SSL_is_dtls(hs->ssl)); assert(hs->expected_client_finished.size() <= 0xff); uint8_t header[4] = { SSL3_MT_FINISHED, 0, 0, static_cast(hs->expected_client_finished.size())}; bool unused_sent_tickets; if (!hs->transcript.Update(header) || !hs->transcript.Update(hs->expected_client_finished) || !tls13_derive_resumption_secret(hs) || !add_new_session_tickets(hs, &unused_sent_tickets)) { return ssl_hs_error; } } hs->tls13_state = state13_read_second_client_flight; return ssl_hs_flush; } static bool uses_end_of_early_data(const SSL *ssl) { // DTLS and QUIC omit the EndOfEarlyData message. See RFC 9001, section 8.3, // and RFC 9147, section 5.6. return !SSL_is_quic(ssl) && !SSL_is_dtls(ssl); } static enum ssl_hs_wait_t do_read_second_client_flight(SSL_HANDSHAKE *hs) { SSL *const ssl = hs->ssl; if (ssl->s3->early_data_accepted) { if (!tls13_set_traffic_key(ssl, ssl_encryption_early_data, evp_aead_open, hs->new_session.get(), hs->early_traffic_secret)) { return ssl_hs_error; } hs->can_early_write = true; hs->can_early_read = true; hs->in_early_data = true; } // If the EndOfEarlyData message is not used, switch to // client_handshake_secret before the early return. if (!uses_end_of_early_data(ssl)) { if (!tls13_set_traffic_key(ssl, ssl_encryption_handshake, evp_aead_open, hs->new_session.get(), hs->client_handshake_secret)) { return ssl_hs_error; } hs->tls13_state = state13_process_end_of_early_data; return ssl->s3->early_data_accepted ? ssl_hs_early_return : ssl_hs_ok; } hs->tls13_state = state13_process_end_of_early_data; return ssl->s3->early_data_accepted ? ssl_hs_read_end_of_early_data : ssl_hs_ok; } static enum ssl_hs_wait_t do_process_end_of_early_data(SSL_HANDSHAKE *hs) { SSL *const ssl = hs->ssl; // In protocols that use EndOfEarlyData, we must consume the extra message and // switch to client_handshake_secret after the early return. if (uses_end_of_early_data(ssl)) { // If early data was not accepted, the EndOfEarlyData will be in the // discarded early data. if (hs->ssl->s3->early_data_accepted) { SSLMessage msg; if (!ssl->method->get_message(ssl, &msg)) { return ssl_hs_read_message; } if (!ssl_check_message_type(ssl, msg, SSL3_MT_END_OF_EARLY_DATA)) { return ssl_hs_error; } if (CBS_len(&msg.body) != 0) { ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR); OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR); return ssl_hs_error; } ssl->method->next_message(ssl); } if (!tls13_set_traffic_key(ssl, ssl_encryption_handshake, evp_aead_open, hs->new_session.get(), hs->client_handshake_secret)) { return ssl_hs_error; } } hs->tls13_state = state13_read_client_encrypted_extensions; return ssl_hs_ok; } static enum ssl_hs_wait_t do_read_client_encrypted_extensions( SSL_HANDSHAKE *hs) { SSL *const ssl = hs->ssl; // For now, only one extension uses client EncryptedExtensions. This function // may be generalized if others use it in the future. if (hs->new_session->has_application_settings && !ssl->s3->early_data_accepted) { SSLMessage msg; if (!ssl->method->get_message(ssl, &msg)) { return ssl_hs_read_message; } if (!ssl_check_message_type(ssl, msg, SSL3_MT_ENCRYPTED_EXTENSIONS)) { return ssl_hs_error; } CBS body = msg.body, extensions; if (!CBS_get_u16_length_prefixed(&body, &extensions) || CBS_len(&body) != 0) { OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR); ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR); return ssl_hs_error; } uint16_t extension_type = TLSEXT_TYPE_application_settings_old; if (hs->config->alps_use_new_codepoint) { extension_type = TLSEXT_TYPE_application_settings; } SSLExtension application_settings(extension_type); uint8_t alert = SSL_AD_DECODE_ERROR; if (!ssl_parse_extensions(&extensions, &alert, {&application_settings}, /*ignore_unknown=*/false)) { ssl_send_alert(ssl, SSL3_AL_FATAL, alert); return ssl_hs_error; } if (!application_settings.present) { OPENSSL_PUT_ERROR(SSL, SSL_R_MISSING_EXTENSION); ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_MISSING_EXTENSION); return ssl_hs_error; } // Note that, if 0-RTT was accepted, these values will already have been // initialized earlier. if (!hs->new_session->peer_application_settings.CopyFrom( application_settings.data) || !ssl_hash_message(hs, msg)) { ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR); return ssl_hs_error; } ssl->method->next_message(ssl); } hs->tls13_state = state13_read_client_certificate; return ssl_hs_ok; } static enum ssl_hs_wait_t do_read_client_certificate(SSL_HANDSHAKE *hs) { SSL *const ssl = hs->ssl; if (!hs->cert_request) { if (!ssl->s3->session_reused) { // OpenSSL returns X509_V_OK when no certificates are requested. This is // classed by them as a bug, but it's assumed by at least NGINX. (Only do // this in full handshakes as resumptions should carry over the previous // |verify_result|, though this is a no-op because servers do not // implement the client's odd soft-fail mode.) hs->new_session->verify_result = X509_V_OK; } // Skip this state. hs->tls13_state = state13_read_channel_id; return ssl_hs_ok; } const bool allow_anonymous = (hs->config->verify_mode & SSL_VERIFY_FAIL_IF_NO_PEER_CERT) == 0; SSLMessage msg; if (!ssl->method->get_message(ssl, &msg)) { return ssl_hs_read_message; } if (!ssl_check_message_type(ssl, msg, SSL3_MT_CERTIFICATE) || !tls13_process_certificate(hs, msg, allow_anonymous) || !ssl_hash_message(hs, msg)) { return ssl_hs_error; } ssl->method->next_message(ssl); hs->tls13_state = state13_read_client_certificate_verify; return ssl_hs_ok; } static enum ssl_hs_wait_t do_read_client_certificate_verify(SSL_HANDSHAKE *hs) { SSL *const ssl = hs->ssl; if (!ssl_session_has_peer_cred(hs->new_session.get())) { // Skip this state. hs->tls13_state = state13_read_channel_id; return ssl_hs_ok; } SSLMessage msg; if (!ssl->method->get_message(ssl, &msg)) { return ssl_hs_read_message; } switch (ssl_verify_peer_cert(hs)) { case ssl_verify_ok: break; case ssl_verify_invalid: return ssl_hs_error; case ssl_verify_retry: hs->tls13_state = state13_read_client_certificate_verify; return ssl_hs_certificate_verify; } if (!ssl_check_message_type(ssl, msg, SSL3_MT_CERTIFICATE_VERIFY) || !tls13_process_certificate_verify(hs, msg) || !ssl_hash_message(hs, msg)) { return ssl_hs_error; } ssl->method->next_message(ssl); hs->tls13_state = state13_read_channel_id; return ssl_hs_ok; } static enum ssl_hs_wait_t do_read_channel_id(SSL_HANDSHAKE *hs) { SSL *const ssl = hs->ssl; if (!hs->channel_id_negotiated) { hs->tls13_state = state13_read_client_finished; return ssl_hs_ok; } SSLMessage msg; if (!ssl->method->get_message(ssl, &msg)) { return ssl_hs_read_message; } if (!ssl_check_message_type(ssl, msg, SSL3_MT_CHANNEL_ID) || // !tls1_verify_channel_id(hs, msg) || // !ssl_hash_message(hs, msg)) { return ssl_hs_error; } ssl->method->next_message(ssl); hs->tls13_state = state13_read_client_finished; return ssl_hs_ok; } static enum ssl_hs_wait_t do_read_client_finished(SSL_HANDSHAKE *hs) { SSL *const ssl = hs->ssl; SSLMessage msg; if (!ssl->method->get_message(ssl, &msg)) { return ssl_hs_read_message; } if (!ssl_check_message_type(ssl, msg, SSL3_MT_FINISHED) || // If early data was accepted, we've already computed the client Finished // and derived the resumption secret. !tls13_process_finished(hs, msg, ssl->s3->early_data_accepted) || // evp_aead_seal keys have already been switched. !tls13_set_traffic_key(ssl, ssl_encryption_application, evp_aead_open, hs->new_session.get(), hs->client_traffic_secret_0)) { return ssl_hs_error; } if (!ssl->s3->early_data_accepted) { if (!ssl_hash_message(hs, msg) || // !tls13_derive_resumption_secret(hs)) { return ssl_hs_error; } // We send post-handshake tickets as part of the handshake in 1-RTT. hs->tls13_state = state13_send_new_session_ticket; } else { // We already sent half-RTT tickets. hs->tls13_state = state13_done; } if (hs->credential != nullptr && hs->credential->type == SSLCredentialType::kSPAKE2PlusV1Server) { // The client has now confirmed that it does know the correct password, so // this connection no longer counts towards the brute force limit. hs->credential->RestorePAKEAttempt(); } ssl->method->next_message(ssl); if (SSL_is_dtls(ssl)) { ssl->method->schedule_ack(ssl); return ssl_hs_flush; } return ssl_hs_ok; } static enum ssl_hs_wait_t do_send_new_session_ticket(SSL_HANDSHAKE *hs) { SSL *const ssl = hs->ssl; bool sent_tickets; if (!add_new_session_tickets(hs, &sent_tickets)) { return ssl_hs_error; } hs->tls13_state = state13_done; // In QUIC and DTLS, we can flush the ticket to the transport immediately. In // TLS over TCP-like transports, we defer until the server performs a write. // This prevents a non-reading client from causing the server to hang in the // case of a small server write buffer. Consumers which don't write data to // the client will need to do a zero-byte write if they wish to flush the // tickets. bool should_flush = sent_tickets && (SSL_is_dtls(ssl) || SSL_is_quic(ssl)); return should_flush ? ssl_hs_flush : ssl_hs_ok; } enum ssl_hs_wait_t tls13_server_handshake(SSL_HANDSHAKE *hs) { while (hs->tls13_state != state13_done) { enum ssl_hs_wait_t ret = ssl_hs_error; enum tls13_server_hs_state_t state = static_cast(hs->tls13_state); switch (state) { case state13_select_parameters: ret = do_select_parameters(hs); break; case state13_select_session: ret = do_select_session(hs); break; case state13_send_hello_retry_request: ret = do_send_hello_retry_request(hs); break; case state13_read_second_client_hello: ret = do_read_second_client_hello(hs); break; case state13_send_server_hello: ret = do_send_server_hello(hs); break; case state13_send_server_certificate_verify: ret = do_send_server_certificate_verify(hs); break; case state13_send_server_finished: ret = do_send_server_finished(hs); break; case state13_send_half_rtt_ticket: ret = do_send_half_rtt_ticket(hs); break; case state13_read_second_client_flight: ret = do_read_second_client_flight(hs); break; case state13_process_end_of_early_data: ret = do_process_end_of_early_data(hs); break; case state13_read_client_encrypted_extensions: ret = do_read_client_encrypted_extensions(hs); break; case state13_read_client_certificate: ret = do_read_client_certificate(hs); break; case state13_read_client_certificate_verify: ret = do_read_client_certificate_verify(hs); break; case state13_read_channel_id: ret = do_read_channel_id(hs); break; case state13_read_client_finished: ret = do_read_client_finished(hs); break; case state13_send_new_session_ticket: ret = do_send_new_session_ticket(hs); break; case state13_done: ret = ssl_hs_ok; break; } if (hs->tls13_state != state) { ssl_do_info_callback(hs->ssl, SSL_CB_ACCEPT_LOOP, 1); } if (ret != ssl_hs_ok) { return ret; } } return ssl_hs_ok; } const char *tls13_server_handshake_state(SSL_HANDSHAKE *hs) { enum tls13_server_hs_state_t state = static_cast(hs->tls13_state); switch (state) { case state13_select_parameters: return "TLS 1.3 server select_parameters"; case state13_select_session: return "TLS 1.3 server select_session"; case state13_send_hello_retry_request: return "TLS 1.3 server send_hello_retry_request"; case state13_read_second_client_hello: return "TLS 1.3 server read_second_client_hello"; case state13_send_server_hello: return "TLS 1.3 server send_server_hello"; case state13_send_server_certificate_verify: return "TLS 1.3 server send_server_certificate_verify"; case state13_send_half_rtt_ticket: return "TLS 1.3 server send_half_rtt_ticket"; case state13_send_server_finished: return "TLS 1.3 server send_server_finished"; case state13_read_second_client_flight: return "TLS 1.3 server read_second_client_flight"; case state13_process_end_of_early_data: return "TLS 1.3 server process_end_of_early_data"; case state13_read_client_encrypted_extensions: return "TLS 1.3 server read_client_encrypted_extensions"; case state13_read_client_certificate: return "TLS 1.3 server read_client_certificate"; case state13_read_client_certificate_verify: return "TLS 1.3 server read_client_certificate_verify"; case state13_read_channel_id: return "TLS 1.3 server read_channel_id"; case state13_read_client_finished: return "TLS 1.3 server read_client_finished"; case state13_send_new_session_ticket: return "TLS 1.3 server send_new_session_ticket"; case state13_done: return "TLS 1.3 server done"; } return "TLS 1.3 server unknown"; } BSSL_NAMESPACE_END