text: /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
   * All rights reserved.
   *
   * This package is an SSL implementation written
   * by Eric Young (eay@cryptsoft.com).
   * The implementation was written so as to conform with Netscapes SSL.
   *
   * This library is free for commercial and non-commercial use as long as
   * the following conditions are aheared to.  The following conditions
   * apply to all code found in this distribution, be it the RC4, RSA,
   * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
   * included with this distribution is covered by the same copyright terms
   * except that the holder is Tim Hudson (tjh@cryptsoft.com).
   *
   * Copyright remains Eric Young's, and as such any Copyright notices in
   * the code are not to be removed.
   * If this package is used in a product, Eric Young should be given attribution
   * as the author of the parts of the library used.
   * This can be in the form of a textual message at program startup or
   * in documentation (online or textual) provided with the package.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   * 1. Redistributions of source code must retain the copyright
   *    notice, this list of conditions and the following disclaimer.
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in the
   *    documentation and/or other materials provided with the distribution.
   * 3. All advertising materials mentioning features or use of this software
   *    must display the following acknowledgement:
   *    "This product includes cryptographic software written by
   *     Eric Young (eay@cryptsoft.com)"
   *    The word 'cryptographic' can be left out if the rouines from the library
   *    being used are not cryptographic related :-).
   * 4. If you include any Windows specific code (or a derivative thereof) from
   *    the apps directory (application code) you must include an acknowledgement:
   *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
   *
   * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
   * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
   * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   * SUCH DAMAGE.
   *
   * The licence and distribution terms for any publically available version or
   * derivative of this code cannot be changed.  i.e. this code cannot simply be
   * copied and put under another distribution licence
   * [including the GNU Public Licence.]
   */
  /* ====================================================================
   * Copyright (c) 1998-2002 The OpenSSL Project.  All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   *
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   *
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in
   *    the documentation and/or other materials provided with the
   *    distribution.
   *
   * 3. All advertising materials mentioning features or use of this
   *    software must display the following acknowledgment:
   *    "This product includes software developed by the OpenSSL Project
   *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
   *
   * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
   *    endorse or promote products derived from this software without
   *    prior written permission. For written permission, please contact
   *    openssl-core@openssl.org.
   *
   * 5. Products derived from this software may not be called "OpenSSL"
   *    nor may "OpenSSL" appear in their names without prior written
   *    permission of the OpenSSL Project.
   *
   * 6. Redistributions of any form whatsoever must retain the following
   *    acknowledgment:
   *    "This product includes software developed by the OpenSSL Project
   *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
   *
   * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
   * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
   * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
   * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
   * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
   * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
   * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
   * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
   * OF THE POSSIBILITY OF SUCH DAMAGE.
   * ====================================================================
   *
   * This product includes cryptographic software written by Eric Young
   * (eay@cryptsoft.com).  This product includes software written by Tim
   * Hudson (tjh@cryptsoft.com). */
  /* ====================================================================
   * Copyright 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED.
   * ECC cipher suite support in OpenSSL originally developed by
   * SUN MICROSYSTEMS, INC., and contributed to the OpenSSL project. */
  
  #include <CNIOBoringSSL_ssl.h>
  
  #include <assert.h>
  
  #include <utility>
  
  #include <CNIOBoringSSL_rand.h>
  
  #include "../crypto/internal.h"
  #include "internal.h"
  
  
  BSSL_NAMESPACE_BEGIN
  
  SSL_HANDSHAKE::SSL_HANDSHAKE(SSL *ssl_arg)
      : ssl(ssl_arg),
        scts_requested(false),
        needs_psk_binder(false),
        handshake_finalized(false),
        accept_psk_mode(false),
        cert_request(false),
        certificate_status_expected(false),
        ocsp_stapling_requested(false),
        delegated_credential_requested(false),
        should_ack_sni(false),
        in_false_start(false),
        in_early_data(false),
        early_data_offered(false),
        can_early_read(false),
        can_early_write(false),
        next_proto_neg_seen(false),
        ticket_expected(false),
        extended_master_secret(false),
        pending_private_key_op(false),
        grease_seeded(false),
        handback(false),
        cert_compression_negotiated(false),
        apply_jdk11_workaround(false) {
    assert(ssl);
  }
  
  SSL_HANDSHAKE::~SSL_HANDSHAKE() {
    ssl->ctx->x509_method->hs_flush_cached_ca_names(this);
  }
  
  void SSL_HANDSHAKE::ResizeSecrets(size_t hash_len) {
    if (hash_len > SSL_MAX_MD_SIZE) {
      abort();
    }
    hash_len_ = hash_len;
  }
  
  UniquePtr<SSL_HANDSHAKE> ssl_handshake_new(SSL *ssl) {
    UniquePtr<SSL_HANDSHAKE> hs = MakeUnique<SSL_HANDSHAKE>(ssl);
    if (!hs || !hs->transcript.Init()) {
      return nullptr;
    }
    hs->config = ssl->config.get();
    if (!hs->config) {
      assert(hs->config);
      return nullptr;
    }
    return hs;
  }
  
  bool ssl_check_message_type(SSL *ssl, const SSLMessage &msg, int type) {
    if (msg.type != type) {
      ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_UNEXPECTED_MESSAGE);
      OPENSSL_PUT_ERROR(SSL, SSL_R_UNEXPECTED_MESSAGE);
      ERR_add_error_dataf("got type %d, wanted type %d", msg.type, type);
      return false;
    }
  
    return true;
  }
  
  bool ssl_add_message_cbb(SSL *ssl, CBB *cbb) {
    Array<uint8_t> msg;
    if (!ssl->method->finish_message(ssl, cbb, &msg) ||
        !ssl->method->add_message(ssl, std::move(msg))) {
      return false;
    }
  
    return true;
  }
  
  size_t ssl_max_handshake_message_len(const SSL *ssl) {
    // kMaxMessageLen is the default maximum message size for handshakes which do
    // not accept peer certificate chains.
    static const size_t kMaxMessageLen = 16384;
  
    if (SSL_in_init(ssl)) {
      SSL_CONFIG *config = ssl->config.get();  // SSL_in_init() implies not NULL.
      if ((!ssl->server || (config->verify_mode & SSL_VERIFY_PEER)) &&
          kMaxMessageLen < ssl->max_cert_list) {
        return ssl->max_cert_list;
      }
      return kMaxMessageLen;
    }
  
    if (ssl_protocol_version(ssl) < TLS1_3_VERSION) {
      // In TLS 1.2 and below, the largest acceptable post-handshake message is
      // a HelloRequest.
      return 0;
    }
  
    if (ssl->server) {
      // The largest acceptable post-handshake message for a server is a
      // KeyUpdate. We will never initiate post-handshake auth.
      return 1;
    }
  
    // Clients must accept NewSessionTicket, so allow the default size.
    return kMaxMessageLen;
  }
  
  bool ssl_hash_message(SSL_HANDSHAKE *hs, const SSLMessage &msg) {
    // V2ClientHello messages are pre-hashed.
    if (msg.is_v2_hello) {
      return true;
    }
  
    return hs->transcript.Update(msg.raw);
  }
  
  bool ssl_parse_extensions(const CBS *cbs, uint8_t *out_alert,
                            Span<const SSL_EXTENSION_TYPE> ext_types,
                            bool ignore_unknown) {
    // Reset everything.
    for (const SSL_EXTENSION_TYPE &ext_type : ext_types) {
      *ext_type.out_present = false;
      CBS_init(ext_type.out_data, nullptr, 0);
    }
  
    CBS copy = *cbs;
    while (CBS_len(&copy) != 0) {
      uint16_t type;
      CBS data;
      if (!CBS_get_u16(&copy, &type) ||
          !CBS_get_u16_length_prefixed(&copy, &data)) {
        OPENSSL_PUT_ERROR(SSL, SSL_R_PARSE_TLSEXT);
        *out_alert = SSL_AD_DECODE_ERROR;
        return false;
      }
  
      const SSL_EXTENSION_TYPE *found = nullptr;
      for (const SSL_EXTENSION_TYPE &ext_type : ext_types) {
        if (type == ext_type.type) {
          found = &ext_type;
          break;
        }
      }
  
      if (found == nullptr) {
        if (ignore_unknown) {
          continue;
        }
        OPENSSL_PUT_ERROR(SSL, SSL_R_UNEXPECTED_EXTENSION);
        *out_alert = SSL_AD_UNSUPPORTED_EXTENSION;
        return false;
      }
  
      // Duplicate ext_types are forbidden.
      if (*found->out_present) {
        OPENSSL_PUT_ERROR(SSL, SSL_R_DUPLICATE_EXTENSION);
        *out_alert = SSL_AD_ILLEGAL_PARAMETER;
        return false;
      }
  
      *found->out_present = 1;
      *found->out_data = data;
    }
  
    return true;
  }
  
  enum ssl_verify_result_t ssl_verify_peer_cert(SSL_HANDSHAKE *hs) {
    SSL *const ssl = hs->ssl;
    const SSL_SESSION *prev_session = ssl->s3->established_session.get();
    if (prev_session != NULL) {
      // If renegotiating, the server must not change the server certificate. See
      // https://mitls.org/pages/attacks/3SHAKE. We never resume on renegotiation,
      // so this check is sufficient to ensure the reported peer certificate never
      // changes on renegotiation.
      assert(!ssl->server);
      if (sk_CRYPTO_BUFFER_num(prev_session->certs.get()) !=
          sk_CRYPTO_BUFFER_num(hs->new_session->certs.get())) {
        OPENSSL_PUT_ERROR(SSL, SSL_R_SERVER_CERT_CHANGED);
        ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER);
        return ssl_verify_invalid;
      }
  
      for (size_t i = 0; i < sk_CRYPTO_BUFFER_num(hs->new_session->certs.get());
           i++) {
        const CRYPTO_BUFFER *old_cert =
            sk_CRYPTO_BUFFER_value(prev_session->certs.get(), i);
        const CRYPTO_BUFFER *new_cert =
            sk_CRYPTO_BUFFER_value(hs->new_session->certs.get(), i);
        if (CRYPTO_BUFFER_len(old_cert) != CRYPTO_BUFFER_len(new_cert) ||
            OPENSSL_memcmp(CRYPTO_BUFFER_data(old_cert),
                           CRYPTO_BUFFER_data(new_cert),
                           CRYPTO_BUFFER_len(old_cert)) != 0) {
          OPENSSL_PUT_ERROR(SSL, SSL_R_SERVER_CERT_CHANGED);
          ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER);
          return ssl_verify_invalid;
        }
      }
  
      // The certificate is identical, so we may skip re-verifying the
      // certificate. Since we only authenticated the previous one, copy other
      // authentication from the established session and ignore what was newly
      // received.
      hs->new_session->ocsp_response = UpRef(prev_session->ocsp_response);
      hs->new_session->signed_cert_timestamp_list =
          UpRef(prev_session->signed_cert_timestamp_list);
      hs->new_session->verify_result = prev_session->verify_result;
      return ssl_verify_ok;
    }
  
    uint8_t alert = SSL_AD_CERTIFICATE_UNKNOWN;
    enum ssl_verify_result_t ret;
    if (hs->config->custom_verify_callback != nullptr) {
      ret = hs->config->custom_verify_callback(ssl, &alert);
      switch (ret) {
        case ssl_verify_ok:
          hs->new_session->verify_result = X509_V_OK;
          break;
        case ssl_verify_invalid:
          // If |SSL_VERIFY_NONE|, the error is non-fatal, but we keep the result.
          if (hs->config->verify_mode == SSL_VERIFY_NONE) {
            ERR_clear_error();
            ret = ssl_verify_ok;
          }
          hs->new_session->verify_result = X509_V_ERR_APPLICATION_VERIFICATION;
          break;
        case ssl_verify_retry:
          break;
      }
    } else {
      ret = ssl->ctx->x509_method->session_verify_cert_chain(
                hs->new_session.get(), hs, &alert)
                ? ssl_verify_ok
                : ssl_verify_invalid;
    }
  
    if (ret == ssl_verify_invalid) {
      OPENSSL_PUT_ERROR(SSL, SSL_R_CERTIFICATE_VERIFY_FAILED);
      ssl_send_alert(ssl, SSL3_AL_FATAL, alert);
    }
  
    // Emulate OpenSSL's client OCSP callback. OpenSSL verifies certificates
    // before it receives the OCSP, so it needs a second callback for OCSP.
    if (ret == ssl_verify_ok && !ssl->server &&
        hs->config->ocsp_stapling_enabled &&
        ssl->ctx->legacy_ocsp_callback != nullptr) {
      int cb_ret =
          ssl->ctx->legacy_ocsp_callback(ssl, ssl->ctx->legacy_ocsp_callback_arg);
      if (cb_ret <= 0) {
        OPENSSL_PUT_ERROR(SSL, SSL_R_OCSP_CB_ERROR);
        ssl_send_alert(ssl, SSL3_AL_FATAL,
                       cb_ret == 0 ? SSL_AD_BAD_CERTIFICATE_STATUS_RESPONSE
                                   : SSL_AD_INTERNAL_ERROR);
        ret = ssl_verify_invalid;
      }
    }
  
    return ret;
  }
  
  // Verifies a stored certificate when resuming a session. A few things are
  // different from verify_peer_cert:
  // 1. We can't be renegotiating if we're resuming a session.
  // 2. The session is immutable, so we don't support verify_mode ==
  // SSL_VERIFY_NONE
  // 3. We don't call the OCSP callback.
  // 4. We only support custom verify callbacks.
  enum ssl_verify_result_t ssl_reverify_peer_cert(SSL_HANDSHAKE *hs,
                                                  bool send_alert) {
    SSL *const ssl = hs->ssl;
    assert(ssl->s3->established_session == nullptr);
    assert(hs->config->verify_mode != SSL_VERIFY_NONE);
  
    uint8_t alert = SSL_AD_CERTIFICATE_UNKNOWN;
    enum ssl_verify_result_t ret = ssl_verify_invalid;
    if (hs->config->custom_verify_callback != nullptr) {
      ret = hs->config->custom_verify_callback(ssl, &alert);
    }
  
    if (ret == ssl_verify_invalid) {
      OPENSSL_PUT_ERROR(SSL, SSL_R_CERTIFICATE_VERIFY_FAILED);
      if (send_alert) {
        ssl_send_alert(ssl, SSL3_AL_FATAL, alert);
      }
    }
  
    return ret;
  }
  
  uint16_t ssl_get_grease_value(SSL_HANDSHAKE *hs,
                                enum ssl_grease_index_t index) {
    // Draw entropy for all GREASE values at once. This avoids calling
    // |RAND_bytes| repeatedly and makes the values consistent within a
    // connection. The latter is so the second ClientHello matches after
    // HelloRetryRequest and so supported_groups and key_shares are consistent.
    if (!hs->grease_seeded) {
      RAND_bytes(hs->grease_seed, sizeof(hs->grease_seed));
      hs->grease_seeded = true;
    }
  
    // This generates a random value of the form 0xωaωa, for all 0 ≤ ω < 16.
    uint16_t ret = hs->grease_seed[index];
    ret = (ret & 0xf0) | 0x0a;
    ret |= ret << 8;
    return ret;
  }
  
  enum ssl_hs_wait_t ssl_get_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)) {
      return ssl_hs_error;
    }
  
    // Snapshot the finished hash before incorporating the new message.
    uint8_t finished[EVP_MAX_MD_SIZE];
    size_t finished_len;
    if (!hs->transcript.GetFinishedMAC(finished, &finished_len,
                                       ssl_handshake_session(hs), !ssl->server) ||
        !ssl_hash_message(hs, msg)) {
      return ssl_hs_error;
    }
  
    int finished_ok = CBS_mem_equal(&msg.body, finished, finished_len);
  #if defined(BORINGSSL_UNSAFE_FUZZER_MODE)
    finished_ok = 1;
  #endif
    if (!finished_ok) {
      ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECRYPT_ERROR);
      OPENSSL_PUT_ERROR(SSL, SSL_R_DIGEST_CHECK_FAILED);
      return ssl_hs_error;
    }
  
    // Copy the Finished so we can use it for renegotiation checks.
    if (finished_len > sizeof(ssl->s3->previous_client_finished) ||
        finished_len > sizeof(ssl->s3->previous_server_finished)) {
      OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
      return ssl_hs_error;
    }
  
    if (ssl->server) {
      OPENSSL_memcpy(ssl->s3->previous_client_finished, finished, finished_len);
      ssl->s3->previous_client_finished_len = finished_len;
    } else {
      OPENSSL_memcpy(ssl->s3->previous_server_finished, finished, finished_len);
      ssl->s3->previous_server_finished_len = finished_len;
    }
  
    // The Finished message should be the end of a 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);
    return ssl_hs_ok;
  }
  
  bool ssl_send_finished(SSL_HANDSHAKE *hs) {
    SSL *const ssl = hs->ssl;
    const SSL_SESSION *session = ssl_handshake_session(hs);
  
    uint8_t finished[EVP_MAX_MD_SIZE];
    size_t finished_len;
    if (!hs->transcript.GetFinishedMAC(finished, &finished_len, session,
                                       ssl->server)) {
      return 0;
    }
  
    // Log the master secret, if logging is enabled.
    if (!ssl_log_secret(
            ssl, "CLIENT_RANDOM",
            MakeConstSpan(session->master_key, session->master_key_length))) {
      return 0;
    }
  
    // Copy the Finished so we can use it for renegotiation checks.
    if (finished_len > sizeof(ssl->s3->previous_client_finished) ||
        finished_len > sizeof(ssl->s3->previous_server_finished)) {
      OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
      return 0;
    }
  
    if (ssl->server) {
      OPENSSL_memcpy(ssl->s3->previous_server_finished, finished, finished_len);
      ssl->s3->previous_server_finished_len = finished_len;
    } else {
      OPENSSL_memcpy(ssl->s3->previous_client_finished, finished, finished_len);
      ssl->s3->previous_client_finished_len = finished_len;
    }
  
    ScopedCBB cbb;
    CBB body;
    if (!ssl->method->init_message(ssl, cbb.get(), &body, SSL3_MT_FINISHED) ||
        !CBB_add_bytes(&body, finished, finished_len) ||
        !ssl_add_message_cbb(ssl, cbb.get())) {
      OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
      return 0;
    }
  
    return 1;
  }
  
  bool ssl_output_cert_chain(SSL_HANDSHAKE *hs) {
    ScopedCBB cbb;
    CBB body;
    if (!hs->ssl->method->init_message(hs->ssl, cbb.get(), &body,
                                       SSL3_MT_CERTIFICATE) ||
        !ssl_add_cert_chain(hs, &body) ||
        !ssl_add_message_cbb(hs->ssl, cbb.get())) {
      OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
      return false;
    }
  
    return true;
  }
  
  const SSL_SESSION *ssl_handshake_session(const SSL_HANDSHAKE *hs) {
    if (hs->new_session) {
      return hs->new_session.get();
    }
    return hs->ssl->session.get();
  }
  
  int ssl_run_handshake(SSL_HANDSHAKE *hs, bool *out_early_return) {
    SSL *const ssl = hs->ssl;
    for (;;) {
      // Resolve the operation the handshake was waiting on.
      switch (hs->wait) {
        case ssl_hs_error:
          ERR_restore_state(hs->error.get());
          return -1;
  
        case ssl_hs_flush: {
          int ret = ssl->method->flush_flight(ssl);
          if (ret <= 0) {
            return ret;
          }
          break;
        }
  
        case ssl_hs_read_server_hello:
        case ssl_hs_read_message:
        case ssl_hs_read_change_cipher_spec: {
          if (ssl->quic_method) {
            hs->wait = ssl_hs_ok;
            // The change cipher spec is omitted in QUIC.
            if (hs->wait != ssl_hs_read_change_cipher_spec) {
              ssl->s3->rwstate = SSL_ERROR_WANT_READ;
              return -1;
            }
            break;
          }
  
          uint8_t alert = SSL_AD_DECODE_ERROR;
          size_t consumed = 0;
          ssl_open_record_t ret;
          if (hs->wait == ssl_hs_read_change_cipher_spec) {
            ret = ssl_open_change_cipher_spec(ssl, &consumed, &alert,
                                              ssl->s3->read_buffer.span());
          } else {
            ret = ssl_open_handshake(ssl, &consumed, &alert,
                                     ssl->s3->read_buffer.span());
          }
          if (ret == ssl_open_record_error &&
              hs->wait == ssl_hs_read_server_hello) {
            uint32_t err = ERR_peek_error();
            if (ERR_GET_LIB(err) == ERR_LIB_SSL &&
                ERR_GET_REASON(err) == SSL_R_SSLV3_ALERT_HANDSHAKE_FAILURE) {
              // Add a dedicated error code to the queue for a handshake_failure
              // alert in response to ClientHello. This matches NSS's client
              // behavior and gives a better error on a (probable) failure to
              // negotiate initial parameters. Note: this error code comes after
              // the original one.
              //
              // See https://crbug.com/446505.
              OPENSSL_PUT_ERROR(SSL, SSL_R_HANDSHAKE_FAILURE_ON_CLIENT_HELLO);
            }
          }
          bool retry;
          int bio_ret = ssl_handle_open_record(ssl, &retry, ret, consumed, alert);
          if (bio_ret <= 0) {
            return bio_ret;
          }
          if (retry) {
            continue;
          }
          ssl->s3->read_buffer.DiscardConsumed();
          break;
        }
  
        case ssl_hs_read_end_of_early_data: {
          if (ssl->s3->hs->can_early_read) {
            // While we are processing early data, the handshake returns early.
            *out_early_return = true;
            return 1;
          }
          hs->wait = ssl_hs_ok;
          break;
        }
  
        case ssl_hs_certificate_selection_pending:
          ssl->s3->rwstate = SSL_ERROR_PENDING_CERTIFICATE;
          hs->wait = ssl_hs_ok;
          return -1;
  
        case ssl_hs_handoff:
          ssl->s3->rwstate = SSL_ERROR_HANDOFF;
          hs->wait = ssl_hs_ok;
          return -1;
  
        case ssl_hs_handback: {
          int ret = ssl->method->flush_flight(ssl);
          if (ret <= 0) {
            return ret;
          }
          ssl->s3->rwstate = SSL_ERROR_HANDBACK;
          hs->wait = ssl_hs_handback;
          return -1;
        }
  
        case ssl_hs_x509_lookup:
          ssl->s3->rwstate = SSL_ERROR_WANT_X509_LOOKUP;
          hs->wait = ssl_hs_ok;
          return -1;
  
        case ssl_hs_channel_id_lookup:
          ssl->s3->rwstate = SSL_ERROR_WANT_CHANNEL_ID_LOOKUP;
          hs->wait = ssl_hs_ok;
          return -1;
  
        case ssl_hs_private_key_operation:
          ssl->s3->rwstate = SSL_ERROR_WANT_PRIVATE_KEY_OPERATION;
          hs->wait = ssl_hs_ok;
          return -1;
  
        case ssl_hs_pending_session:
          ssl->s3->rwstate = SSL_ERROR_PENDING_SESSION;
          hs->wait = ssl_hs_ok;
          return -1;
  
        case ssl_hs_pending_ticket:
          ssl->s3->rwstate = SSL_ERROR_PENDING_TICKET;
          hs->wait = ssl_hs_ok;
          return -1;
  
        case ssl_hs_certificate_verify:
          ssl->s3->rwstate = SSL_ERROR_WANT_CERTIFICATE_VERIFY;
          hs->wait = ssl_hs_ok;
          return -1;
  
        case ssl_hs_early_data_rejected:
          assert(ssl->s3->early_data_reason != ssl_early_data_unknown);
          assert(!hs->can_early_write);
          ssl->s3->rwstate = SSL_ERROR_EARLY_DATA_REJECTED;
          return -1;
  
        case ssl_hs_early_return:
          *out_early_return = true;
          hs->wait = ssl_hs_ok;
          return 1;
  
        case ssl_hs_ok:
          break;
      }
  
      // Run the state machine again.
      hs->wait = ssl->do_handshake(hs);
      if (hs->wait == ssl_hs_error) {
        hs->error.reset(ERR_save_state());
        return -1;
      }
      if (hs->wait == ssl_hs_ok) {
        // The handshake has completed.
        *out_early_return = false;
        return 1;
      }
  
      // Otherwise, loop to the beginning and resolve what was blocking the
      // handshake.
    }
  }
  
  BSSL_NAMESPACE_END
  