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) 1998-2007 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.
   */
  /* ====================================================================
   * Copyright 2005 Nokia. All rights reserved.
   *
   * The portions of the attached software ("Contribution") is developed by
   * Nokia Corporation and is licensed pursuant to the OpenSSL open source
   * license.
   *
   * The Contribution, originally written by Mika Kousa and Pasi Eronen of
   * Nokia Corporation, consists of the "PSK" (Pre-Shared Key) ciphersuites
   * support (see RFC 4279) to OpenSSL.
   *
   * No patent licenses or other rights except those expressly stated in
   * the OpenSSL open source license shall be deemed granted or received
   * expressly, by implication, estoppel, or otherwise.
   *
   * No assurances are provided by Nokia that the Contribution does not
   * infringe the patent or other intellectual property rights of any third
   * party or that the license provides you with all the necessary rights
   * to make use of the Contribution.
   *
   * THE SOFTWARE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. IN
   * ADDITION TO THE DISCLAIMERS INCLUDED IN THE LICENSE, NOKIA
   * SPECIFICALLY DISCLAIMS ANY LIABILITY FOR CLAIMS BROUGHT BY YOU OR ANY
   * OTHER ENTITY BASED ON INFRINGEMENT OF INTELLECTUAL PROPERTY RIGHTS OR
   * OTHERWISE. */
  
  #include <assert.h>
  #include <stdio.h>
  #include <string.h>
  
  #include <openssl/bytestring.h>
  #include <openssl/dh.h>
  #include <openssl/err.h>
  #include <openssl/lhash.h>
  #include <openssl/mem.h>
  #include <openssl/obj.h>
  #include <openssl/rand.h>
  #include <openssl/x509v3.h>
  
  #include "internal.h"
  #include "../crypto/internal.h"
  
  
  /* Some error codes are special. Ensure the make_errors.go script never
   * regresses this. */
  OPENSSL_COMPILE_ASSERT(SSL_R_TLSV1_ALERT_NO_RENEGOTIATION ==
                             SSL_AD_NO_RENEGOTIATION + SSL_AD_REASON_OFFSET,
                         ssl_alert_reason_code_mismatch);
  
  /* kMaxHandshakeSize is the maximum size, in bytes, of a handshake message. */
  static const size_t kMaxHandshakeSize = (1u << 24) - 1;
  
  static CRYPTO_EX_DATA_CLASS g_ex_data_class_ssl = CRYPTO_EX_DATA_CLASS_INIT;
  static CRYPTO_EX_DATA_CLASS g_ex_data_class_ssl_ctx = CRYPTO_EX_DATA_CLASS_INIT;
  
  int SSL_clear(SSL *ssl) {
    if (ssl->method == NULL) {
      OPENSSL_PUT_ERROR(SSL, SSL_clear, SSL_R_NO_METHOD_SPECIFIED);
      return 0;
    }
  
    if (ssl_clear_bad_session(ssl)) {
      SSL_SESSION_free(ssl->session);
      ssl->session = NULL;
    }
  
    ssl->hit = 0;
    ssl->shutdown = 0;
  
    /* SSL_clear may be called before or after the |ssl| is initialized in either
     * accept or connect state. In the latter case, SSL_clear should preserve the
     * half and reset |ssl->state| accordingly. */
    if (ssl->handshake_func != NULL) {
      if (ssl->server) {
        SSL_set_accept_state(ssl);
      } else {
        SSL_set_connect_state(ssl);
      }
    } else {
      assert(ssl->state == 0);
    }
  
    /* TODO(davidben): Some state on |ssl| is reset both in |SSL_new| and
     * |SSL_clear| because it is per-connection state rather than configuration
     * state. Per-connection state should be on |ssl->s3| and |ssl->d1| so it is
     * naturally reset at the right points between |SSL_new|, |SSL_clear|, and
     * |ssl3_new|. */
  
    ssl->rwstate = SSL_NOTHING;
    ssl->rstate = SSL_ST_READ_HEADER;
  
    BUF_MEM_free(ssl->init_buf);
    ssl->init_buf = NULL;
  
    ssl->packet = NULL;
    ssl->packet_length = 0;
  
    ssl_clear_cipher_ctx(ssl);
  
    OPENSSL_free(ssl->next_proto_negotiated);
    ssl->next_proto_negotiated = NULL;
    ssl->next_proto_negotiated_len = 0;
  
    /* The ssl->d1->mtu is simultaneously configuration (preserved across
     * clear) and connection-specific state (gets reset).
     *
     * TODO(davidben): Avoid this. */
    unsigned mtu = 0;
    if (ssl->d1 != NULL) {
      mtu = ssl->d1->mtu;
    }
  
    ssl->method->ssl_free(ssl);
    if (!ssl->method->ssl_new(ssl)) {
      return 0;
    }
    ssl->enc_method = ssl3_get_enc_method(ssl->version);
    assert(ssl->enc_method != NULL);
  
    if (SSL_IS_DTLS(ssl) && (SSL_get_options(ssl) & SSL_OP_NO_QUERY_MTU)) {
      ssl->d1->mtu = mtu;
    }
  
    ssl->client_version = ssl->version;
  
    return 1;
  }
  
  SSL *SSL_new(SSL_CTX *ctx) {
    SSL *s;
  
    if (ctx == NULL) {
      OPENSSL_PUT_ERROR(SSL, SSL_new, SSL_R_NULL_SSL_CTX);
      return NULL;
    }
    if (ctx->method == NULL) {
      OPENSSL_PUT_ERROR(SSL, SSL_new, SSL_R_SSL_CTX_HAS_NO_DEFAULT_SSL_VERSION);
      return NULL;
    }
  
    s = (SSL *)OPENSSL_malloc(sizeof(SSL));
    if (s == NULL) {
      goto err;
    }
    memset(s, 0, sizeof(SSL));
  
    s->min_version = ctx->min_version;
    s->max_version = ctx->max_version;
  
    s->options = ctx->options;
    s->mode = ctx->mode;
    s->max_cert_list = ctx->max_cert_list;
  
    s->cert = ssl_cert_dup(ctx->cert);
    if (s->cert == NULL) {
      goto err;
    }
  
    s->msg_callback = ctx->msg_callback;
    s->msg_callback_arg = ctx->msg_callback_arg;
    s->verify_mode = ctx->verify_mode;
    s->sid_ctx_length = ctx->sid_ctx_length;
    assert(s->sid_ctx_length <= sizeof s->sid_ctx);
    memcpy(&s->sid_ctx, &ctx->sid_ctx, sizeof(s->sid_ctx));
    s->verify_callback = ctx->default_verify_callback;
    s->generate_session_id = ctx->generate_session_id;
  
    s->param = X509_VERIFY_PARAM_new();
    if (!s->param) {
      goto err;
    }
    X509_VERIFY_PARAM_inherit(s->param, ctx->param);
    s->quiet_shutdown = ctx->quiet_shutdown;
    s->max_send_fragment = ctx->max_send_fragment;
  
    CRYPTO_refcount_inc(&ctx->references);
    s->ctx = ctx;
    s->tlsext_ticket_expected = 0;
    CRYPTO_refcount_inc(&ctx->references);
    s->initial_ctx = ctx;
    if (ctx->tlsext_ecpointformatlist) {
      s->tlsext_ecpointformatlist = BUF_memdup(
          ctx->tlsext_ecpointformatlist, ctx->tlsext_ecpointformatlist_length);
      if (!s->tlsext_ecpointformatlist) {
        goto err;
      }
      s->tlsext_ecpointformatlist_length = ctx->tlsext_ecpointformatlist_length;
    }
  
    if (ctx->tlsext_ellipticcurvelist) {
      s->tlsext_ellipticcurvelist =
          BUF_memdup(ctx->tlsext_ellipticcurvelist,
                     ctx->tlsext_ellipticcurvelist_length * 2);
      if (!s->tlsext_ellipticcurvelist) {
        goto err;
      }
      s->tlsext_ellipticcurvelist_length = ctx->tlsext_ellipticcurvelist_length;
    }
    s->next_proto_negotiated = NULL;
  
    if (s->ctx->alpn_client_proto_list) {
      s->alpn_client_proto_list = BUF_memdup(s->ctx->alpn_client_proto_list,
                                             s->ctx->alpn_client_proto_list_len);
      if (s->alpn_client_proto_list == NULL) {
        goto err;
      }
      s->alpn_client_proto_list_len = s->ctx->alpn_client_proto_list_len;
    }
  
    s->verify_result = X509_V_OK;
    s->method = ctx->method;
  
    if (!s->method->ssl_new(s)) {
      goto err;
    }
    s->enc_method = ssl3_get_enc_method(s->version);
    assert(s->enc_method != NULL);
  
    s->rwstate = SSL_NOTHING;
    s->rstate = SSL_ST_READ_HEADER;
  
    CRYPTO_new_ex_data(&g_ex_data_class_ssl, s, &s->ex_data);
  
    s->psk_identity_hint = NULL;
    if (ctx->psk_identity_hint) {
      s->psk_identity_hint = BUF_strdup(ctx->psk_identity_hint);
      if (s->psk_identity_hint == NULL) {
        goto err;
      }
    }
    s->psk_client_callback = ctx->psk_client_callback;
    s->psk_server_callback = ctx->psk_server_callback;
  
    s->tlsext_channel_id_enabled = ctx->tlsext_channel_id_enabled;
    if (ctx->tlsext_channel_id_private) {
      s->tlsext_channel_id_private =
          EVP_PKEY_up_ref(ctx->tlsext_channel_id_private);
    }
  
    s->signed_cert_timestamps_enabled = s->ctx->signed_cert_timestamps_enabled;
    s->ocsp_stapling_enabled = s->ctx->ocsp_stapling_enabled;
  
    return s;
  
  err:
    SSL_free(s);
    OPENSSL_PUT_ERROR(SSL, SSL_new, ERR_R_MALLOC_FAILURE);
  
    return NULL;
  }
  
  int SSL_CTX_set_session_id_context(SSL_CTX *ctx, const uint8_t *sid_ctx,
                                     unsigned int sid_ctx_len) {
    if (sid_ctx_len > sizeof ctx->sid_ctx) {
      OPENSSL_PUT_ERROR(SSL, SSL_CTX_set_session_id_context,
                        SSL_R_SSL_SESSION_ID_CONTEXT_TOO_LONG);
      return 0;
    }
    ctx->sid_ctx_length = sid_ctx_len;
    memcpy(ctx->sid_ctx, sid_ctx, sid_ctx_len);
  
    return 1;
  }
  
  int SSL_set_session_id_context(SSL *ssl, const uint8_t *sid_ctx,
                                 unsigned int sid_ctx_len) {
    if (sid_ctx_len > SSL_MAX_SID_CTX_LENGTH) {
      OPENSSL_PUT_ERROR(SSL, SSL_set_session_id_context,
                        SSL_R_SSL_SESSION_ID_CONTEXT_TOO_LONG);
      return 0;
    }
    ssl->sid_ctx_length = sid_ctx_len;
    memcpy(ssl->sid_ctx, sid_ctx, sid_ctx_len);
  
    return 1;
  }
  
  int SSL_CTX_set_generate_session_id(SSL_CTX *ctx, GEN_SESSION_CB cb) {
    ctx->generate_session_id = cb;
    return 1;
  }
  
  int SSL_set_generate_session_id(SSL *ssl, GEN_SESSION_CB cb) {
    ssl->generate_session_id = cb;
    return 1;
  }
  
  int SSL_has_matching_session_id(const SSL *ssl, const uint8_t *id,
                                  unsigned int id_len) {
    /* A quick examination of SSL_SESSION_hash and SSL_SESSION_cmp shows how we
     * can "construct" a session to give us the desired check - ie. to find if
     * there's a session in the hash table that would conflict with any new
     * session built out of this id/id_len and the ssl_version in use by this
     * SSL. */
    SSL_SESSION r, *p;
  
    if (id_len > sizeof r.session_id) {
      return 0;
    }
  
    r.ssl_version = ssl->version;
    r.session_id_length = id_len;
    memcpy(r.session_id, id, id_len);
  
    CRYPTO_MUTEX_lock_read(&ssl->ctx->lock);
    p = lh_SSL_SESSION_retrieve(ssl->ctx->sessions, &r);
    CRYPTO_MUTEX_unlock(&ssl->ctx->lock);
    return p != NULL;
  }
  
  int SSL_CTX_set_purpose(SSL_CTX *s, int purpose) {
    return X509_VERIFY_PARAM_set_purpose(s->param, purpose);
  }
  
  int SSL_set_purpose(SSL *s, int purpose) {
    return X509_VERIFY_PARAM_set_purpose(s->param, purpose);
  }
  
  int SSL_CTX_set_trust(SSL_CTX *s, int trust) {
    return X509_VERIFY_PARAM_set_trust(s->param, trust);
  }
  
  int SSL_set_trust(SSL *s, int trust) {
    return X509_VERIFY_PARAM_set_trust(s->param, trust);
  }
  
  int SSL_CTX_set1_param(SSL_CTX *ctx, X509_VERIFY_PARAM *vpm) {
    return X509_VERIFY_PARAM_set1(ctx->param, vpm);
  }
  
  int SSL_set1_param(SSL *ssl, X509_VERIFY_PARAM *vpm) {
    return X509_VERIFY_PARAM_set1(ssl->param, vpm);
  }
  
  void ssl_cipher_preference_list_free(
      struct ssl_cipher_preference_list_st *cipher_list) {
    if (cipher_list == NULL) {
      return;
    }
    sk_SSL_CIPHER_free(cipher_list->ciphers);
    OPENSSL_free(cipher_list->in_group_flags);
    OPENSSL_free(cipher_list);
  }
  
  struct ssl_cipher_preference_list_st *ssl_cipher_preference_list_dup(
      struct ssl_cipher_preference_list_st *cipher_list) {
    struct ssl_cipher_preference_list_st *ret = NULL;
    size_t n = sk_SSL_CIPHER_num(cipher_list->ciphers);
  
    ret = OPENSSL_malloc(sizeof(struct ssl_cipher_preference_list_st));
    if (!ret) {
      goto err;
    }
  
    ret->ciphers = NULL;
    ret->in_group_flags = NULL;
    ret->ciphers = sk_SSL_CIPHER_dup(cipher_list->ciphers);
    if (!ret->ciphers) {
      goto err;
    }
    ret->in_group_flags = BUF_memdup(cipher_list->in_group_flags, n);
    if (!ret->in_group_flags) {
      goto err;
    }
  
    return ret;
  
  err:
    ssl_cipher_preference_list_free(ret);
    return NULL;
  }
  
  struct ssl_cipher_preference_list_st *ssl_cipher_preference_list_from_ciphers(
      STACK_OF(SSL_CIPHER) *ciphers) {
    struct ssl_cipher_preference_list_st *ret = NULL;
    size_t n = sk_SSL_CIPHER_num(ciphers);
  
    ret = OPENSSL_malloc(sizeof(struct ssl_cipher_preference_list_st));
    if (!ret) {
      goto err;
    }
    ret->ciphers = NULL;
    ret->in_group_flags = NULL;
    ret->ciphers = sk_SSL_CIPHER_dup(ciphers);
    if (!ret->ciphers) {
      goto err;
    }
    ret->in_group_flags = OPENSSL_malloc(n);
    if (!ret->in_group_flags) {
      goto err;
    }
    memset(ret->in_group_flags, 0, n);
    return ret;
  
  err:
    ssl_cipher_preference_list_free(ret);
    return NULL;
  }
  
  X509_VERIFY_PARAM *SSL_CTX_get0_param(SSL_CTX *ctx) { return ctx->param; }
  
  X509_VERIFY_PARAM *SSL_get0_param(SSL *ssl) { return ssl->param; }
  
  void SSL_certs_clear(SSL *s) { ssl_cert_clear_certs(s->cert); }
  
  void SSL_free(SSL *ssl) {
    if (ssl == NULL) {
      return;
    }
  
    X509_VERIFY_PARAM_free(ssl->param);
  
    CRYPTO_free_ex_data(&g_ex_data_class_ssl, ssl, &ssl->ex_data);
  
    if (ssl->bbio != NULL) {
      /* If the buffering BIO is in place, pop it off */
      if (ssl->bbio == ssl->wbio) {
        ssl->wbio = BIO_pop(ssl->wbio);
      }
      BIO_free(ssl->bbio);
      ssl->bbio = NULL;
    }
  
    int free_wbio = ssl->wbio != ssl->rbio;
    BIO_free_all(ssl->rbio);
    if (free_wbio) {
      BIO_free_all(ssl->wbio);
    }
  
    BUF_MEM_free(ssl->init_buf);
  
    /* add extra stuff */
    ssl_cipher_preference_list_free(ssl->cipher_list);
    sk_SSL_CIPHER_free(ssl->cipher_list_by_id);
  
    ssl_clear_bad_session(ssl);
    SSL_SESSION_free(ssl->session);
  
    ssl_clear_cipher_ctx(ssl);
  
    ssl_cert_free(ssl->cert);
  
    OPENSSL_free(ssl->tlsext_hostname);
    SSL_CTX_free(ssl->initial_ctx);
    OPENSSL_free(ssl->tlsext_ecpointformatlist);
    OPENSSL_free(ssl->tlsext_ellipticcurvelist);
    OPENSSL_free(ssl->alpn_client_proto_list);
    EVP_PKEY_free(ssl->tlsext_channel_id_private);
    OPENSSL_free(ssl->psk_identity_hint);
    sk_X509_NAME_pop_free(ssl->client_CA, X509_NAME_free);
    OPENSSL_free(ssl->next_proto_negotiated);
    sk_SRTP_PROTECTION_PROFILE_free(ssl->srtp_profiles);
  
    if (ssl->method != NULL) {
      ssl->method->ssl_free(ssl);
    }
    SSL_CTX_free(ssl->ctx);
  
    OPENSSL_free(ssl);
  }
  
  void SSL_set_bio(SSL *s, BIO *rbio, BIO *wbio) {
    /* If the output buffering BIO is still in place, remove it. */
    if (s->bbio != NULL) {
      if (s->wbio == s->bbio) {
        s->wbio = s->wbio->next_bio;
        s->bbio->next_bio = NULL;
      }
    }
  
    if (s->rbio != rbio) {
      BIO_free_all(s->rbio);
    }
    if (s->wbio != wbio && s->rbio != s->wbio) {
      BIO_free_all(s->wbio);
    }
    s->rbio = rbio;
    s->wbio = wbio;
  }
  
  BIO *SSL_get_rbio(const SSL *s) { return s->rbio; }
  
  BIO *SSL_get_wbio(const SSL *s) { return s->wbio; }
  
  int SSL_get_fd(const SSL *s) { return SSL_get_rfd(s); }
  
  int SSL_get_rfd(const SSL *s) {
    int ret = -1;
    BIO *b, *r;
  
    b = SSL_get_rbio(s);
    r = BIO_find_type(b, BIO_TYPE_DESCRIPTOR);
    if (r != NULL) {
      BIO_get_fd(r, &ret);
    }
    return ret;
  }
  
  int SSL_get_wfd(const SSL *s) {
    int ret = -1;
    BIO *b, *r;
  
    b = SSL_get_wbio(s);
    r = BIO_find_type(b, BIO_TYPE_DESCRIPTOR);
    if (r != NULL) {
      BIO_get_fd(r, &ret);
    }
  
    return ret;
  }
  
  int SSL_set_fd(SSL *s, int fd) {
    int ret = 0;
    BIO *bio = NULL;
  
    bio = BIO_new(BIO_s_fd());
  
    if (bio == NULL) {
      OPENSSL_PUT_ERROR(SSL, SSL_set_fd, ERR_R_BUF_LIB);
      goto err;
    }
    BIO_set_fd(bio, fd, BIO_NOCLOSE);
    SSL_set_bio(s, bio, bio);
    ret = 1;
  
  err:
    return ret;
  }
  
  int SSL_set_wfd(SSL *s, int fd) {
    int ret = 0;
    BIO *bio = NULL;
  
    if (s->rbio == NULL || BIO_method_type(s->rbio) != BIO_TYPE_FD ||
        (int)BIO_get_fd(s->rbio, NULL) != fd) {
      bio = BIO_new(BIO_s_fd());
  
      if (bio == NULL) {
        OPENSSL_PUT_ERROR(SSL, SSL_set_wfd, ERR_R_BUF_LIB);
        goto err;
      }
      BIO_set_fd(bio, fd, BIO_NOCLOSE);
      SSL_set_bio(s, SSL_get_rbio(s), bio);
    } else {
      SSL_set_bio(s, SSL_get_rbio(s), SSL_get_rbio(s));
    }
  
    ret = 1;
  
  err:
    return ret;
  }
  
  int SSL_set_rfd(SSL *s, int fd) {
    int ret = 0;
    BIO *bio = NULL;
  
    if (s->wbio == NULL || BIO_method_type(s->wbio) != BIO_TYPE_FD ||
        (int)BIO_get_fd(s->wbio, NULL) != fd) {
      bio = BIO_new(BIO_s_fd());
  
      if (bio == NULL) {
        OPENSSL_PUT_ERROR(SSL, SSL_set_rfd, ERR_R_BUF_LIB);
        goto err;
      }
      BIO_set_fd(bio, fd, BIO_NOCLOSE);
      SSL_set_bio(s, bio, SSL_get_wbio(s));
    } else {
      SSL_set_bio(s, SSL_get_wbio(s), SSL_get_wbio(s));
    }
    ret = 1;
  
  err:
    return ret;
  }
  
  /* return length of latest Finished message we sent, copy to 'buf' */
  size_t SSL_get_finished(const SSL *s, void *buf, size_t count) {
    size_t ret = 0;
  
    if (s->s3 != NULL) {
      ret = s->s3->tmp.finish_md_len;
      if (count > ret) {
        count = ret;
      }
      memcpy(buf, s->s3->tmp.finish_md, count);
    }
  
    return ret;
  }
  
  /* return length of latest Finished message we expected, copy to 'buf' */
  size_t SSL_get_peer_finished(const SSL *s, void *buf, size_t count) {
    size_t ret = 0;
  
    if (s->s3 != NULL) {
      ret = s->s3->tmp.peer_finish_md_len;
      if (count > ret) {
        count = ret;
      }
      memcpy(buf, s->s3->tmp.peer_finish_md, count);
    }
  
    return ret;
  }
  
  int SSL_get_verify_mode(const SSL *s) { return s->verify_mode; }
  
  int SSL_get_verify_depth(const SSL *s) {
    return X509_VERIFY_PARAM_get_depth(s->param);
  }
  
  int (*SSL_get_verify_callback(const SSL *s))(int, X509_STORE_CTX *) {
    return s->verify_callback;
  }
  
  int SSL_CTX_get_verify_mode(const SSL_CTX *ctx) { return ctx->verify_mode; }
  
  int SSL_CTX_get_verify_depth(const SSL_CTX *ctx) {
    return X509_VERIFY_PARAM_get_depth(ctx->param);
  }
  
  int (*SSL_CTX_get_verify_callback(const SSL_CTX *ctx))(int, X509_STORE_CTX *) {
    return ctx->default_verify_callback;
  }
  
  void SSL_set_verify(SSL *s, int mode,
                      int (*callback)(int ok, X509_STORE_CTX *ctx)) {
    s->verify_mode = mode;
    if (callback != NULL) {
      s->verify_callback = callback;
    }
  }
  
  void SSL_set_verify_depth(SSL *s, int depth) {
    X509_VERIFY_PARAM_set_depth(s->param, depth);
  }
  
  int SSL_CTX_get_read_ahead(const SSL_CTX *ctx) { return 0; }
  
  int SSL_get_read_ahead(const SSL *s) { return 0; }
  
  void SSL_CTX_set_read_ahead(SSL_CTX *ctx, int yes) { }
  
  void SSL_set_read_ahead(SSL *s, int yes) { }
  
  int SSL_pending(const SSL *s) {
    if (s->rstate == SSL_ST_READ_BODY) {
      return 0;
    }
  
    return (s->s3->rrec.type == SSL3_RT_APPLICATION_DATA) ? s->s3->rrec.length
                                                          : 0;
  }
  
  X509 *SSL_get_peer_certificate(const SSL *s) {
    X509 *r;
  
    if (s == NULL || s->session == NULL) {
      r = NULL;
    } else {
      r = s->session->peer;
    }
  
    if (r == NULL) {
      return NULL;
    }
  
    return X509_up_ref(r);
  }
  
  STACK_OF(X509) *SSL_get_peer_cert_chain(const SSL *s) {
    STACK_OF(X509) *r;
  
    if (s == NULL || s->session == NULL || s->session->sess_cert == NULL) {
      r = NULL;
    } else {
      r = s->session->sess_cert->cert_chain;
    }
  
    /* If we are a client, cert_chain includes the peer's own certificate; if we
     * are a server, it does not. */
    return r;
  }
  
  /* Fix this so it checks all the valid key/cert options */
  int SSL_CTX_check_private_key(const SSL_CTX *ctx) {
    if (ctx == NULL || ctx->cert == NULL || ctx->cert->key->x509 == NULL) {
      OPENSSL_PUT_ERROR(SSL, SSL_CTX_check_private_key,
                        SSL_R_NO_CERTIFICATE_ASSIGNED);
      return 0;
    }
  
    if (ctx->cert->key->privatekey == NULL) {
      OPENSSL_PUT_ERROR(SSL, SSL_CTX_check_private_key,
                        SSL_R_NO_PRIVATE_KEY_ASSIGNED);
      return 0;
    }
  
    return X509_check_private_key(ctx->cert->key->x509,
                                  ctx->cert->key->privatekey);
  }
  
  /* Fix this function so that it takes an optional type parameter */
  int SSL_check_private_key(const SSL *ssl) {
    if (ssl == NULL) {
      OPENSSL_PUT_ERROR(SSL, SSL_check_private_key, ERR_R_PASSED_NULL_PARAMETER);
      return 0;
    }
  
    if (ssl->cert == NULL) {
      OPENSSL_PUT_ERROR(SSL, SSL_check_private_key,
                        SSL_R_NO_CERTIFICATE_ASSIGNED);
      return 0;
    }
  
    if (ssl->cert->key->x509 == NULL) {
      OPENSSL_PUT_ERROR(SSL, SSL_check_private_key,
                        SSL_R_NO_CERTIFICATE_ASSIGNED);
      return 0;
    }
  
    if (ssl->cert->key->privatekey == NULL) {
      OPENSSL_PUT_ERROR(SSL, SSL_check_private_key,
                        SSL_R_NO_PRIVATE_KEY_ASSIGNED);
      return 0;
    }
  
    return X509_check_private_key(ssl->cert->key->x509,
                                  ssl->cert->key->privatekey);
  }
  
  int SSL_accept(SSL *s) {
    if (s->handshake_func == 0) {
      /* Not properly initialized yet */
      SSL_set_accept_state(s);
    }
  
    if (s->handshake_func != s->method->ssl_accept) {
      OPENSSL_PUT_ERROR(SSL, SSL_accept, ERR_R_INTERNAL_ERROR);
      return -1;
    }
  
    return s->handshake_func(s);
  }
  
  int SSL_connect(SSL *s) {
    if (s->handshake_func == 0) {
      /* Not properly initialized yet */
      SSL_set_connect_state(s);
    }
  
    if (s->handshake_func != s->method->ssl_connect) {
      OPENSSL_PUT_ERROR(SSL, SSL_connect, ERR_R_INTERNAL_ERROR);
      return -1;
    }
  
    return s->handshake_func(s);
  }
  
  long SSL_get_default_timeout(const SSL *s) {
    return SSL_DEFAULT_SESSION_TIMEOUT;
  }
  
  int SSL_read(SSL *s, void *buf, int num) {
    if (s->handshake_func == 0) {
      OPENSSL_PUT_ERROR(SSL, SSL_read, SSL_R_UNINITIALIZED);
      return -1;
    }
  
    if (s->shutdown & SSL_RECEIVED_SHUTDOWN) {
      s->rwstate = SSL_NOTHING;
      return 0;
    }
  
    ERR_clear_system_error();
    return s->method->ssl_read_app_data(s, buf, num, 0);
  }
  
  int SSL_peek(SSL *s, void *buf, int num) {
    if (s->handshake_func == 0) {
      OPENSSL_PUT_ERROR(SSL, SSL_peek, SSL_R_UNINITIALIZED);
      return -1;
    }
  
    if (s->shutdown & SSL_RECEIVED_SHUTDOWN) {
      return 0;
    }
  
    ERR_clear_system_error();
    return s->method->ssl_read_app_data(s, buf, num, 1);
  }
  
  int SSL_write(SSL *s, const void *buf, int num) {
    if (s->handshake_func == 0) {
      OPENSSL_PUT_ERROR(SSL, SSL_write, SSL_R_UNINITIALIZED);
      return -1;
    }
  
    if (s->shutdown & SSL_SENT_SHUTDOWN) {
      s->rwstate = SSL_NOTHING;
      OPENSSL_PUT_ERROR(SSL, SSL_write, SSL_R_PROTOCOL_IS_SHUTDOWN);
      return -1;
    }
  
    ERR_clear_system_error();
    return s->method->ssl_write_app_data(s, buf, num);
  }
  
  int SSL_shutdown(SSL *s) {
    /* Note that this function behaves differently from what one might expect.
     * Return values are 0 for no success (yet), 1 for success; but calling it
     * once is usually not enough, even if blocking I/O is used (see
     * ssl3_shutdown). */
  
    if (s->handshake_func == 0) {
      OPENSSL_PUT_ERROR(SSL, SSL_shutdown, SSL_R_UNINITIALIZED);
      return -1;
    }
  
    if (SSL_in_init(s)) {
      return 1;
    }
  
    /* Do nothing if configured not to send a close_notify. */
    if (s->quiet_shutdown) {
      s->shutdown = SSL_SENT_SHUTDOWN | SSL_RECEIVED_SHUTDOWN;
      return 1;
    }
  
    if (!(s->shutdown & SSL_SENT_SHUTDOWN)) {
      s->shutdown |= SSL_SENT_SHUTDOWN;
      ssl3_send_alert(s, SSL3_AL_WARNING, SSL_AD_CLOSE_NOTIFY);
  
      /* our shutdown alert has been sent now, and if it still needs to be
       * written, s->s3->alert_dispatch will be true */
      if (s->s3->alert_dispatch) {
        return -1; /* return WANT_WRITE */
      }
    } else if (s->s3->alert_dispatch) {
      /* resend it if not sent */
      int ret = s->method->ssl_dispatch_alert(s);
      if (ret == -1) {
        /* we only get to return -1 here the 2nd/Nth invocation, we must  have
         * already signalled return 0 upon a previous invoation, return
         * WANT_WRITE */
        return ret;
      }
    } else if (!(s->shutdown & SSL_RECEIVED_SHUTDOWN)) {
      /* If we are waiting for a close from our peer, we are closed */
      s->method->ssl_read_close_notify(s);
      if (!(s->shutdown & SSL_RECEIVED_SHUTDOWN)) {
        return -1; /* return WANT_READ */
      }
    }
  
    if (s->shutdown == (SSL_SENT_SHUTDOWN | SSL_RECEIVED_SHUTDOWN) &&
        !s->s3->alert_dispatch) {
      return 1;
    } else {
      return 0;
    }
  }
  
  int SSL_renegotiate(SSL *ssl) {
    /* Caller-initiated renegotiation is not supported. */
    OPENSSL_PUT_ERROR(SSL, SSL_renegotiate, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
    return 0;
  }
  
  int SSL_renegotiate_pending(SSL *ssl) {
    return SSL_in_init(ssl) && ssl->s3->initial_handshake_complete;
  }
  
  uint32_t SSL_CTX_set_options(SSL_CTX *ctx, uint32_t options) {
    ctx->options |= options;
    return ctx->options;
  }
  
  uint32_t SSL_set_options(SSL *ssl, uint32_t options) {
    ssl->options |= options;
    return ssl->options;
  }
  
  uint32_t SSL_CTX_clear_options(SSL_CTX *ctx, uint32_t options) {
    ctx->options &= ~options;
    return ctx->options;
  }
  
  uint32_t SSL_clear_options(SSL *ssl, uint32_t options) {
    ssl->options &= ~options;
    return ssl->options;
  }
  
  uint32_t SSL_CTX_get_options(const SSL_CTX *ctx) { return ctx->options; }
  
  uint32_t SSL_get_options(const SSL *ssl) { return ssl->options; }
  
  uint32_t SSL_CTX_set_mode(SSL_CTX *ctx, uint32_t mode) {
    ctx->mode |= mode;
    return ctx->mode;
  }
  
  uint32_t SSL_set_mode(SSL *ssl, uint32_t mode) {
    ssl->mode |= mode;
    return ssl->mode;
  }
  
  uint32_t SSL_CTX_clear_mode(SSL_CTX *ctx, uint32_t mode) {
    ctx->mode &= ~mode;
    return ctx->mode;
  }
  
  uint32_t SSL_clear_mode(SSL *ssl, uint32_t mode) {
    ssl->mode &= ~mode;
    return ssl->mode;
  }
  
  uint32_t SSL_CTX_get_mode(const SSL_CTX *ctx) { return ctx->mode; }
  
  uint32_t SSL_get_mode(const SSL *ssl) { return ssl->mode; }
  
  size_t SSL_CTX_get_max_cert_list(const SSL_CTX *ctx) {
    return ctx->max_cert_list;
  }
  
  void SSL_CTX_set_max_cert_list(SSL_CTX *ctx, size_t max_cert_list) {
    if (max_cert_list > kMaxHandshakeSize) {
      max_cert_list = kMaxHandshakeSize;
    }
    ctx->max_cert_list = (uint32_t)max_cert_list;
  }
  
  size_t SSL_get_max_cert_list(const SSL *ssl) {
    return ssl->max_cert_list;
  }
  
  void SSL_set_max_cert_list(SSL *ssl, size_t max_cert_list) {
    if (max_cert_list > kMaxHandshakeSize) {
      max_cert_list = kMaxHandshakeSize;
    }
    ssl->max_cert_list = (uint32_t)max_cert_list;
  }
  
  void SSL_CTX_set_max_send_fragment(SSL_CTX *ctx, size_t max_send_fragment) {
    if (max_send_fragment < 512) {
      max_send_fragment = 512;
    }
    if (max_send_fragment > SSL3_RT_MAX_PLAIN_LENGTH) {
      max_send_fragment = SSL3_RT_MAX_PLAIN_LENGTH;
    }
    ctx->max_send_fragment = (uint16_t)max_send_fragment;
  }
  
  void SSL_set_max_send_fragment(SSL *ssl, size_t max_send_fragment) {
    if (max_send_fragment < 512) {
      max_send_fragment = 512;
    }
    if (max_send_fragment > SSL3_RT_MAX_PLAIN_LENGTH) {
      max_send_fragment = SSL3_RT_MAX_PLAIN_LENGTH;
    }
    ssl->max_send_fragment = (uint16_t)max_send_fragment;
  }
  
  int SSL_set_mtu(SSL *ssl, unsigned mtu) {
    if (!SSL_IS_DTLS(ssl) || mtu < dtls1_min_mtu()) {
      return 0;
    }
    ssl->d1->mtu = mtu;
    return 1;
  }
  
  int SSL_get_secure_renegotiation_support(const SSL *ssl) {
    return ssl->s3->send_connection_binding;
  }
  
  long SSL_ctrl(SSL *s, int cmd, long larg, void *parg) {
    return s->method->ssl_ctrl(s, cmd, larg, parg);
  }
  
  LHASH_OF(SSL_SESSION) *SSL_CTX_sessions(SSL_CTX *ctx) { return ctx->sessions; }
  
  size_t SSL_CTX_sess_number(const SSL_CTX *ctx) {
    return lh_SSL_SESSION_num_items(ctx->sessions);
  }
  
  unsigned long SSL_CTX_sess_set_cache_size(SSL_CTX *ctx, unsigned long size) {
    unsigned long ret = ctx->session_cache_size;
    ctx->session_cache_size = size;
    return ret;
  }
  
  unsigned long SSL_CTX_sess_get_cache_size(const SSL_CTX *ctx) {
    return ctx->session_cache_size;
  }
  
  int SSL_CTX_set_session_cache_mode(SSL_CTX *ctx, int mode) {
    int ret = ctx->session_cache_mode;
    ctx->session_cache_mode = mode;
    return ret;
  }
  
  int SSL_CTX_get_session_cache_mode(const SSL_CTX *ctx) {
    return ctx->session_cache_mode;
  }
  
  long SSL_CTX_ctrl(SSL_CTX *ctx, int cmd, long larg, void *parg) {
    return ctx->method->ssl_ctx_ctrl(ctx, cmd, larg, parg);
  }
  
  /* return a STACK of the ciphers available for the SSL and in order of
   * preference */
  STACK_OF(SSL_CIPHER) *SSL_get_ciphers(const SSL *s) {
    if (s == NULL) {
      return NULL;
    }
  
    if (s->cipher_list != NULL) {
      return s->cipher_list->ciphers;
    }
  
    if (s->version >= TLS1_1_VERSION && s->ctx != NULL &&
        s->ctx->cipher_list_tls11 != NULL) {
      return s->ctx->cipher_list_tls11->ciphers;
    }
  
    if (s->ctx != NULL && s->ctx->cipher_list != NULL) {
      return s->ctx->cipher_list->ciphers;
    }
  
    return NULL;
  }
  
  /* return a STACK of the ciphers available for the SSL and in order of
   * algorithm id */
  STACK_OF(SSL_CIPHER) *ssl_get_ciphers_by_id(SSL *s) {
    if (s == NULL) {
      return NULL;
    }
  
    if (s->cipher_list_by_id != NULL) {
      return s->cipher_list_by_id;
    }
  
    if (s->ctx != NULL && s->ctx->cipher_list_by_id != NULL) {
      return s->ctx->cipher_list_by_id;
    }
  
    return NULL;
  }
  
  /* The old interface to get the same thing as SSL_get_ciphers() */
  const char *SSL_get_cipher_list(const SSL *s, int n) {
    const SSL_CIPHER *c;
    STACK_OF(SSL_CIPHER) *sk;
  
    if (s == NULL) {
      return NULL;
    }
  
    sk = SSL_get_ciphers(s);
    if (sk == NULL || n < 0 || (size_t)n >= sk_SSL_CIPHER_num(sk)) {
      return NULL;
    }
  
    c = sk_SSL_CIPHER_value(sk, n);
    if (c == NULL) {
      return NULL;
    }
  
    return c->name;
  }
  
  /* specify the ciphers to be used by default by the SSL_CTX */
  int SSL_CTX_set_cipher_list(SSL_CTX *ctx, const char *str) {
    STACK_OF(SSL_CIPHER) *sk;
  
    sk = ssl_create_cipher_list(ctx->method, &ctx->cipher_list,
                                &ctx->cipher_list_by_id, str);
    /* ssl_create_cipher_list may return an empty stack if it was unable to find
     * a cipher matching the given rule string (for example if the rule string
     * specifies a cipher which has been disabled). This is not an error as far
     * as ssl_create_cipher_list is concerned, and hence ctx->cipher_list and
     * ctx->cipher_list_by_id has been updated. */
    if (sk == NULL) {
      return 0;
    } else if (sk_SSL_CIPHER_num(sk) == 0) {
      OPENSSL_PUT_ERROR(SSL, SSL_CTX_set_cipher_list, SSL_R_NO_CIPHER_MATCH);
      return 0;
    }
  
    return 1;
  }
  
  int SSL_CTX_set_cipher_list_tls11(SSL_CTX *ctx, const char *str) {
    STACK_OF(SSL_CIPHER) *sk;
  
    sk = ssl_create_cipher_list(ctx->method, &ctx->cipher_list_tls11, NULL, str);
    if (sk == NULL) {
      return 0;
    } else if (sk_SSL_CIPHER_num(sk) == 0) {
      OPENSSL_PUT_ERROR(SSL, SSL_CTX_set_cipher_list_tls11,
                        SSL_R_NO_CIPHER_MATCH);
      return 0;
    }
  
    return 1;
  }
  
  /* specify the ciphers to be used by the SSL */
  int SSL_set_cipher_list(SSL *s, const char *str) {
    STACK_OF(SSL_CIPHER) *sk;
  
    sk = ssl_create_cipher_list(s->ctx->method, &s->cipher_list,
                                &s->cipher_list_by_id, str);
  
    /* see comment in SSL_CTX_set_cipher_list */
    if (sk == NULL) {
      return 0;
    } else if (sk_SSL_CIPHER_num(sk) == 0) {
      OPENSSL_PUT_ERROR(SSL, SSL_set_cipher_list, SSL_R_NO_CIPHER_MATCH);
      return 0;
    }
  
    return 1;
  }
  
  int ssl_cipher_list_to_bytes(SSL *s, STACK_OF(SSL_CIPHER) *sk, uint8_t *p) {
    size_t i;
    const SSL_CIPHER *c;
    CERT *ct = s->cert;
    uint8_t *q;
    /* Set disabled masks for this session */
    ssl_set_client_disabled(s);
  
    if (sk == NULL) {
      return 0;
    }
    q = p;
  
    for (i = 0; i < sk_SSL_CIPHER_num(sk); i++) {
      c = sk_SSL_CIPHER_value(sk, i);
      /* Skip disabled ciphers */
      if (c->algorithm_ssl & ct->mask_ssl ||
          c->algorithm_mkey & ct->mask_k ||
          c->algorithm_auth & ct->mask_a) {
        continue;
      }
      s2n(ssl_cipher_get_value(c), p);
    }
  
    /* If all ciphers were disabled, return the error to the caller. */
    if (p == q) {
      return 0;
    }
  
    /* Add SCSVs. */
    if (!s->s3->initial_handshake_complete) {
      s2n(SSL3_CK_SCSV & 0xffff, p);
    }
  
    if (s->mode & SSL_MODE_SEND_FALLBACK_SCSV) {
      s2n(SSL3_CK_FALLBACK_SCSV & 0xffff, p);
    }
  
    return p - q;
  }
  
  STACK_OF(SSL_CIPHER) *ssl_bytes_to_cipher_list(SSL *s, const CBS *cbs) {
    CBS cipher_suites = *cbs;
    const SSL_CIPHER *c;
    STACK_OF(SSL_CIPHER) *sk;
  
    if (s->s3) {
      s->s3->send_connection_binding = 0;
    }
  
    if (CBS_len(&cipher_suites) % 2 != 0) {
      OPENSSL_PUT_ERROR(SSL, ssl_bytes_to_cipher_list,
                        SSL_R_ERROR_IN_RECEIVED_CIPHER_LIST);
      return NULL;
    }
  
    sk = sk_SSL_CIPHER_new_null();
    if (sk == NULL) {
      OPENSSL_PUT_ERROR(SSL, ssl_bytes_to_cipher_list, ERR_R_MALLOC_FAILURE);
      goto err;
    }
  
    while (CBS_len(&cipher_suites) > 0) {
      uint16_t cipher_suite;
  
      if (!CBS_get_u16(&cipher_suites, &cipher_suite)) {
        OPENSSL_PUT_ERROR(SSL, ssl_bytes_to_cipher_list, ERR_R_INTERNAL_ERROR);
        goto err;
      }
  
      /* Check for SCSV. */
      if (s->s3 && cipher_suite == (SSL3_CK_SCSV & 0xffff)) {
        /* SCSV is fatal if renegotiating. */
        if (s->s3->initial_handshake_complete) {
          OPENSSL_PUT_ERROR(SSL, ssl_bytes_to_cipher_list,
                            SSL_R_SCSV_RECEIVED_WHEN_RENEGOTIATING);
          ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_HANDSHAKE_FAILURE);
          goto err;
        }
        s->s3->send_connection_binding = 1;
        continue;
      }
  
      /* Check for FALLBACK_SCSV. */
      if (s->s3 && cipher_suite == (SSL3_CK_FALLBACK_SCSV & 0xffff)) {
        uint16_t max_version = ssl3_get_max_server_version(s);
        if (SSL_IS_DTLS(s) ? (uint16_t)s->version > max_version
                           : (uint16_t)s->version < max_version) {
          OPENSSL_PUT_ERROR(SSL, ssl_bytes_to_cipher_list,
                            SSL_R_INAPPROPRIATE_FALLBACK);
          ssl3_send_alert(s, SSL3_AL_FATAL, SSL3_AD_INAPPROPRIATE_FALLBACK);
          goto err;
        }
        continue;
      }
  
      c = SSL_get_cipher_by_value(cipher_suite);
      if (c != NULL && !sk_SSL_CIPHER_push(sk, c)) {
        OPENSSL_PUT_ERROR(SSL, ssl_bytes_to_cipher_list, ERR_R_MALLOC_FAILURE);
        goto err;
      }
    }
  
    return sk;
  
  err:
    sk_SSL_CIPHER_free(sk);
    return NULL;
  }
  
  
  /* return a servername extension value if provided in Client Hello, or NULL. So
   * far, only host_name types are defined (RFC 3546). */
  const char *SSL_get_servername(const SSL *s, const int type) {
    if (type != TLSEXT_NAMETYPE_host_name) {
      return NULL;
    }
  
    return s->session && !s->tlsext_hostname ? s->session->tlsext_hostname
                                             : s->tlsext_hostname;
  }
  
  int SSL_get_servername_type(const SSL *s) {
    if (s->session &&
        (!s->tlsext_hostname ? s->session->tlsext_hostname : s->tlsext_hostname)) {
      return TLSEXT_NAMETYPE_host_name;
    }
  
    return -1;
  }
  
  void SSL_CTX_enable_signed_cert_timestamps(SSL_CTX *ctx) {
    ctx->signed_cert_timestamps_enabled = 1;
  }
  
  int SSL_enable_signed_cert_timestamps(SSL *ssl) {
    ssl->signed_cert_timestamps_enabled = 1;
    return 1;
  }
  
  void SSL_CTX_enable_ocsp_stapling(SSL_CTX *ctx) {
    ctx->ocsp_stapling_enabled = 1;
  }
  
  int SSL_enable_ocsp_stapling(SSL *ssl) {
    ssl->ocsp_stapling_enabled = 1;
    return 1;
  }
  
  void SSL_get0_signed_cert_timestamp_list(const SSL *ssl, const uint8_t **out,
                                           size_t *out_len) {
    SSL_SESSION *session = ssl->session;
  
    *out_len = 0;
    *out = NULL;
    if (ssl->server || !session || !session->tlsext_signed_cert_timestamp_list) {
      return;
    }
  
    *out = session->tlsext_signed_cert_timestamp_list;
    *out_len = session->tlsext_signed_cert_timestamp_list_length;
  }
  
  void SSL_get0_ocsp_response(const SSL *ssl, const uint8_t **out,
                              size_t *out_len) {
    SSL_SESSION *session = ssl->session;
  
    *out_len = 0;
    *out = NULL;
    if (ssl->server || !session || !session->ocsp_response) {
      return;
    }
    *out = session->ocsp_response;
    *out_len = session->ocsp_response_length;
  }
  
  /* SSL_select_next_proto implements the standard protocol selection. It is
   * expected that this function is called from the callback set by
   * SSL_CTX_set_next_proto_select_cb.
   *
   * The protocol data is assumed to be a vector of 8-bit, length prefixed byte
   * strings. The length byte itself is not included in the length. A byte
   * string of length 0 is invalid. No byte string may be truncated.
   *
   * The current, but experimental algorithm for selecting the protocol is:
   *
   * 1) If the server doesn't support NPN then this is indicated to the
   * callback. In this case, the client application has to abort the connection
   * or have a default application level protocol.
   *
   * 2) If the server supports NPN, but advertises an empty list then the
   * client selects the first protcol in its list, but indicates via the
   * API that this fallback case was enacted.
   *
   * 3) Otherwise, the client finds the first protocol in the server's list
   * that it supports and selects this protocol. This is because it's
   * assumed that the server has better information about which protocol
   * a client should use.
   *
   * 4) If the client doesn't support any of the server's advertised
   * protocols, then this is treated the same as case 2.
   *
   * It returns either
   * OPENSSL_NPN_NEGOTIATED if a common protocol was found, or
   * OPENSSL_NPN_NO_OVERLAP if the fallback case was reached.
   */
  int SSL_select_next_proto(uint8_t **out, uint8_t *outlen, const uint8_t *server,
                            unsigned int server_len, const uint8_t *client,
                            unsigned int client_len) {
    unsigned int i, j;
    const uint8_t *result;
    int status = OPENSSL_NPN_UNSUPPORTED;
  
    /* For each protocol in server preference order, see if we support it. */
    for (i = 0; i < server_len;) {
      for (j = 0; j < client_len;) {
        if (server[i] == client[j] &&
            memcmp(&server[i + 1], &client[j + 1], server[i]) == 0) {
          /* We found a match */
          result = &server[i];
          status = OPENSSL_NPN_NEGOTIATED;
          goto found;
        }
        j += client[j];
        j++;
      }
      i += server[i];
      i++;
    }
  
    /* There's no overlap between our protocols and the server's list. */
    result = client;
    status = OPENSSL_NPN_NO_OVERLAP;
  
  found:
    *out = (uint8_t *)result + 1;
    *outlen = result[0];
    return status;
  }
  
  /* SSL_get0_next_proto_negotiated sets *data and *len to point to the client's
   * requested protocol for this connection and returns 0. If the client didn't
   * request any protocol, then *data is set to NULL.
   *
   * Note that the client can request any protocol it chooses. The value returned
   * from this function need not be a member of the list of supported protocols
   * provided by the callback. */
  void SSL_get0_next_proto_negotiated(const SSL *s, const uint8_t **data,
                                      unsigned *len) {
    *data = s->next_proto_negotiated;
    if (!*data) {
      *len = 0;
    } else {
      *len = s->next_proto_negotiated_len;
    }
  }
  
  /* SSL_CTX_set_next_protos_advertised_cb sets a callback that is called when a
   * TLS server needs a list of supported protocols for Next Protocol
   * Negotiation. The returned list must be in wire format.  The list is returned
   * by setting |out| to point to it and |outlen| to its length. This memory will
   * not be modified, but one should assume that the SSL* keeps a reference to
   * it.
   *
   * The callback should return SSL_TLSEXT_ERR_OK if it wishes to advertise.
   * Otherwise, no such extension will be included in the ServerHello. */
  void SSL_CTX_set_next_protos_advertised_cb(
      SSL_CTX *ctx,
      int (*cb)(SSL *ssl, const uint8_t **out, unsigned int *outlen, void *arg),
      void *arg) {
    ctx->next_protos_advertised_cb = cb;
    ctx->next_protos_advertised_cb_arg = arg;
  }
  
  /* SSL_CTX_set_next_proto_select_cb sets a callback that is called when a
   * client needs to select a protocol from the server's provided list. |out|
   * must be set to point to the selected protocol (which may be within |in|).
   * The length of the protocol name must be written into |outlen|. The server's
   * advertised protocols are provided in |in| and |inlen|. The callback can
   * assume that |in| is syntactically valid.
   *
   * The client must select a protocol. It is fatal to the connection if this
   * callback returns a value other than SSL_TLSEXT_ERR_OK.
   */
  void SSL_CTX_set_next_proto_select_cb(
      SSL_CTX *ctx, int (*cb)(SSL *s, uint8_t **out, uint8_t *outlen,
                              const uint8_t *in, unsigned int inlen, void *arg),
      void *arg) {
    ctx->next_proto_select_cb = cb;
    ctx->next_proto_select_cb_arg = arg;
  }
  
  int SSL_CTX_set_alpn_protos(SSL_CTX *ctx, const uint8_t *protos,
                              unsigned protos_len) {
    OPENSSL_free(ctx->alpn_client_proto_list);
    ctx->alpn_client_proto_list = BUF_memdup(protos, protos_len);
    if (!ctx->alpn_client_proto_list) {
      return 1;
    }
    ctx->alpn_client_proto_list_len = protos_len;
  
    return 0;
  }
  
  int SSL_set_alpn_protos(SSL *ssl, const uint8_t *protos, unsigned protos_len) {
    OPENSSL_free(ssl->alpn_client_proto_list);
    ssl->alpn_client_proto_list = BUF_memdup(protos, protos_len);
    if (!ssl->alpn_client_proto_list) {
      return 1;
    }
    ssl->alpn_client_proto_list_len = protos_len;
  
    return 0;
  }
  
  /* SSL_CTX_set_alpn_select_cb sets a callback function on |ctx| that is called
   * during ClientHello processing in order to select an ALPN protocol from the
   * client's list of offered protocols. */
  void SSL_CTX_set_alpn_select_cb(SSL_CTX *ctx,
                                  int (*cb)(SSL *ssl, const uint8_t **out,
                                            uint8_t *outlen, const uint8_t *in,
                                            unsigned int inlen, void *arg),
                                  void *arg) {
    ctx->alpn_select_cb = cb;
    ctx->alpn_select_cb_arg = arg;
  }
  
  /* SSL_get0_alpn_selected gets the selected ALPN protocol (if any) from |ssl|.
   * On return it sets |*data| to point to |*len| bytes of protocol name (not
   * including the leading length-prefix byte). If the server didn't respond with
   * a negotiated protocol then |*len| will be zero. */
  void SSL_get0_alpn_selected(const SSL *ssl, const uint8_t **data,
                              unsigned *len) {
    *data = NULL;
    if (ssl->s3) {
      *data = ssl->s3->alpn_selected;
    }
    if (*data == NULL) {
      *len = 0;
    } else {
      *len = ssl->s3->alpn_selected_len;
    }
  }
  
  int SSL_export_keying_material(SSL *s, uint8_t *out, size_t out_len,
                                 const char *label, size_t label_len,
                                 const uint8_t *context, size_t context_len,
                                 int use_context) {
    if (s->version < TLS1_VERSION) {
      return 0;
    }
  
    return s->enc_method->export_keying_material(
        s, out, out_len, label, label_len, context, context_len, use_context);
  }
  
  static uint32_t ssl_session_hash(const SSL_SESSION *a) {
    uint32_t hash =
        ((uint32_t)a->session_id[0]) ||
        ((uint32_t)a->session_id[1] << 8) ||
        ((uint32_t)a->session_id[2] << 16) ||
        ((uint32_t)a->session_id[3] << 24);
  
    return hash;
  }
  
  /* NB: If this function (or indeed the hash function which uses a sort of
   * coarser function than this one) is changed, ensure
   * SSL_CTX_has_matching_session_id() is checked accordingly. It relies on being
   * able to construct an SSL_SESSION that will collide with any existing session
   * with a matching session ID. */
  static int ssl_session_cmp(const SSL_SESSION *a, const SSL_SESSION *b) {
    if (a->ssl_version != b->ssl_version) {
      return 1;
    }
  
    if (a->session_id_length != b->session_id_length) {
      return 1;
    }
  
    return memcmp(a->session_id, b->session_id, a->session_id_length);
  }
  
  SSL_CTX *SSL_CTX_new(const SSL_METHOD *method) {
    SSL_CTX *ret = NULL;
  
    if (method == NULL) {
      OPENSSL_PUT_ERROR(SSL, SSL_CTX_new, SSL_R_NULL_SSL_METHOD_PASSED);
      return NULL;
    }
  
    if (SSL_get_ex_data_X509_STORE_CTX_idx() < 0) {
      OPENSSL_PUT_ERROR(SSL, SSL_CTX_new, SSL_R_X509_VERIFICATION_SETUP_PROBLEMS);
      goto err;
    }
  
    ret = (SSL_CTX *)OPENSSL_malloc(sizeof(SSL_CTX));
    if (ret == NULL) {
      goto err;
    }
  
    memset(ret, 0, sizeof(SSL_CTX));
  
    ret->method = method->method;
  
    CRYPTO_MUTEX_init(&ret->lock);
  
    ret->cert_store = NULL;
    ret->session_cache_mode = SSL_SESS_CACHE_SERVER;
    ret->session_cache_size = SSL_SESSION_CACHE_MAX_SIZE_DEFAULT;
    ret->session_cache_head = NULL;
    ret->session_cache_tail = NULL;
  
    /* We take the system default */
    ret->session_timeout = SSL_DEFAULT_SESSION_TIMEOUT;
  
    ret->new_session_cb = 0;
    ret->remove_session_cb = 0;
    ret->get_session_cb = 0;
    ret->generate_session_id = 0;
  
    ret->references = 1;
    ret->quiet_shutdown = 0;
  
    ret->info_callback = NULL;
  
    ret->app_verify_callback = 0;
    ret->app_verify_arg = NULL;
  
    ret->max_cert_list = SSL_MAX_CERT_LIST_DEFAULT;
    ret->msg_callback = 0;
    ret->msg_callback_arg = NULL;
    ret->verify_mode = SSL_VERIFY_NONE;
    ret->sid_ctx_length = 0;
    ret->default_verify_callback = NULL;
    ret->cert = ssl_cert_new();
    if (ret->cert == NULL) {
      goto err;
    }
  
    ret->default_passwd_callback = 0;
    ret->default_passwd_callback_userdata = NULL;
    ret->client_cert_cb = 0;
  
    ret->sessions = lh_SSL_SESSION_new(ssl_session_hash, ssl_session_cmp);
    if (ret->sessions == NULL) {
      goto err;
    }
    ret->cert_store = X509_STORE_new();
    if (ret->cert_store == NULL) {
      goto err;
    }
  
    ssl_create_cipher_list(ret->method, &ret->cipher_list,
                           &ret->cipher_list_by_id, SSL_DEFAULT_CIPHER_LIST);
    if (ret->cipher_list == NULL ||
        sk_SSL_CIPHER_num(ret->cipher_list->ciphers) <= 0) {
      OPENSSL_PUT_ERROR(SSL, SSL_CTX_new, SSL_R_LIBRARY_HAS_NO_CIPHERS);
      goto err2;
    }
  
    ret->param = X509_VERIFY_PARAM_new();
    if (!ret->param) {
      goto err;
    }
  
    ret->client_CA = sk_X509_NAME_new_null();
    if (ret->client_CA == NULL) {
      goto err;
    }
  
    CRYPTO_new_ex_data(&g_ex_data_class_ssl_ctx, ret, &ret->ex_data);
  
    ret->extra_certs = NULL;
  
    ret->max_send_fragment = SSL3_RT_MAX_PLAIN_LENGTH;
  
    ret->tlsext_servername_callback = 0;
    ret->tlsext_servername_arg = NULL;
    /* Setup RFC4507 ticket keys */
    if (!RAND_bytes(ret->tlsext_tick_key_name, 16) ||
        !RAND_bytes(ret->tlsext_tick_hmac_key, 16) ||
        !RAND_bytes(ret->tlsext_tick_aes_key, 16)) {
      ret->options |= SSL_OP_NO_TICKET;
    }
  
    ret->next_protos_advertised_cb = 0;
    ret->next_proto_select_cb = 0;
    ret->psk_identity_hint = NULL;
    ret->psk_client_callback = NULL;
    ret->psk_server_callback = NULL;
  
    /* Default is to connect to non-RI servers. When RI is more widely deployed
     * might change this. */
    ret->options |= SSL_OP_LEGACY_SERVER_CONNECT;
  
    /* Lock the SSL_CTX to the specified version, for compatibility with legacy
     * uses of SSL_METHOD. */
    if (method->version != 0) {
      SSL_CTX_set_max_version(ret, method->version);
      SSL_CTX_set_min_version(ret, method->version);
    }
  
    return ret;
  
  err:
    OPENSSL_PUT_ERROR(SSL, SSL_CTX_new, ERR_R_MALLOC_FAILURE);
  err2:
    SSL_CTX_free(ret);
    return NULL;
  }
  
  void SSL_CTX_free(SSL_CTX *ctx) {
    if (ctx == NULL ||
        !CRYPTO_refcount_dec_and_test_zero(&ctx->references)) {
      return;
    }
  
    X509_VERIFY_PARAM_free(ctx->param);
  
    /* Free internal session cache. However: the remove_cb() may reference the
     * ex_data of SSL_CTX, thus the ex_data store can only be removed after the
     * sessions were flushed. As the ex_data handling routines might also touch
     * the session cache, the most secure solution seems to be: empty (flush) the
     * cache, then free ex_data, then finally free the cache. (See ticket
     * [openssl.org #212].) */
    SSL_CTX_flush_sessions(ctx, 0);
  
    CRYPTO_free_ex_data(&g_ex_data_class_ssl_ctx, ctx, &ctx->ex_data);
  
    CRYPTO_MUTEX_cleanup(&ctx->lock);
    lh_SSL_SESSION_free(ctx->sessions);
    X509_STORE_free(ctx->cert_store);
    ssl_cipher_preference_list_free(ctx->cipher_list);
    sk_SSL_CIPHER_free(ctx->cipher_list_by_id);
    ssl_cipher_preference_list_free(ctx->cipher_list_tls11);
    ssl_cert_free(ctx->cert);
    sk_X509_NAME_pop_free(ctx->client_CA, X509_NAME_free);
    sk_X509_pop_free(ctx->extra_certs, X509_free);
    sk_SRTP_PROTECTION_PROFILE_free(ctx->srtp_profiles);
    OPENSSL_free(ctx->psk_identity_hint);
    OPENSSL_free(ctx->tlsext_ecpointformatlist);
    OPENSSL_free(ctx->tlsext_ellipticcurvelist);
    OPENSSL_free(ctx->alpn_client_proto_list);
    EVP_PKEY_free(ctx->tlsext_channel_id_private);
    BIO_free(ctx->keylog_bio);
  
    OPENSSL_free(ctx);
  }
  
  void SSL_CTX_set_default_passwd_cb(SSL_CTX *ctx, pem_password_cb *cb) {
    ctx->default_passwd_callback = cb;
  }
  
  void SSL_CTX_set_default_passwd_cb_userdata(SSL_CTX *ctx, void *u) {
    ctx->default_passwd_callback_userdata = u;
  }
  
  void SSL_CTX_set_cert_verify_callback(SSL_CTX *ctx,
                                        int (*cb)(X509_STORE_CTX *, void *),
                                        void *arg) {
    ctx->app_verify_callback = cb;
    ctx->app_verify_arg = arg;
  }
  
  void SSL_CTX_set_verify(SSL_CTX *ctx, int mode,
                          int (*cb)(int, X509_STORE_CTX *)) {
    ctx->verify_mode = mode;
    ctx->default_verify_callback = cb;
  }
  
  void SSL_CTX_set_verify_depth(SSL_CTX *ctx, int depth) {
    X509_VERIFY_PARAM_set_depth(ctx->param, depth);
  }
  
  void SSL_CTX_set_cert_cb(SSL_CTX *c, int (*cb)(SSL *ssl, void *arg),
                           void *arg) {
    ssl_cert_set_cert_cb(c->cert, cb, arg);
  }
  
  void SSL_set_cert_cb(SSL *s, int (*cb)(SSL *ssl, void *arg), void *arg) {
    ssl_cert_set_cert_cb(s->cert, cb, arg);
  }
  
  static int ssl_has_key(SSL *s, size_t idx) {
    CERT_PKEY *cpk = &s->cert->pkeys[idx];
    return cpk->x509 && cpk->privatekey;
  }
  
  void ssl_get_compatible_server_ciphers(SSL *s, uint32_t *out_mask_k,
                                         uint32_t *out_mask_a) {
    CERT *c = s->cert;
    int rsa_enc, rsa_sign, dh_tmp;
    uint32_t mask_k, mask_a;
    int have_ecc_cert, ecdsa_ok;
    X509 *x;
  
    if (c == NULL) {
      /* TODO(davidben): Is this codepath possible? */
      *out_mask_k = 0;
      *out_mask_a = 0;
      return;
    }
  
    dh_tmp = (c->dh_tmp != NULL || c->dh_tmp_cb != NULL);
  
    rsa_enc = ssl_has_key(s, SSL_PKEY_RSA_ENC);
    rsa_sign = ssl_has_key(s, SSL_PKEY_RSA_SIGN);
    have_ecc_cert = ssl_has_key(s, SSL_PKEY_ECC);
    mask_k = 0;
    mask_a = 0;
  
    if (rsa_enc) {
      mask_k |= SSL_kRSA;
    }
    if (dh_tmp) {
      mask_k |= SSL_kDHE;
    }
    if (rsa_enc || rsa_sign) {
      mask_a |= SSL_aRSA;
    }
  
    /* An ECC certificate may be usable for ECDSA cipher suites depending on the
     * key usage extension and on the client's curve preferences. */
    if (have_ecc_cert) {
      x = c->pkeys[SSL_PKEY_ECC].x509;
      /* This call populates extension flags (ex_flags). */
      X509_check_purpose(x, -1, 0);
      ecdsa_ok = (x->ex_flags & EXFLAG_KUSAGE)
                     ? (x->ex_kusage & X509v3_KU_DIGITAL_SIGNATURE)
                     : 1;
      if (!tls1_check_ec_cert(s, x)) {
        ecdsa_ok = 0;
      }
      if (ecdsa_ok) {
        mask_a |= SSL_aECDSA;
      }
    }
  
    /* If we are considering an ECC cipher suite that uses an ephemeral EC
     * key, check it. */
    if (tls1_check_ec_tmp_key(s)) {
      mask_k |= SSL_kECDHE;
    }
  
    /* PSK requires a server callback. */
    if (s->psk_server_callback != NULL) {
      mask_k |= SSL_kPSK;
      mask_a |= SSL_aPSK;
    }
  
    *out_mask_k = mask_k;
    *out_mask_a = mask_a;
  }
  
  static int ssl_get_server_cert_index(const SSL *s) {
    int idx;
    idx = ssl_cipher_get_cert_index(s->s3->tmp.new_cipher);
    if (idx == SSL_PKEY_RSA_ENC && !s->cert->pkeys[SSL_PKEY_RSA_ENC].x509) {
      idx = SSL_PKEY_RSA_SIGN;
    }
    if (idx == -1) {
      OPENSSL_PUT_ERROR(SSL, ssl_get_server_cert_index, ERR_R_INTERNAL_ERROR);
    }
    return idx;
  }
  
  CERT_PKEY *ssl_get_server_send_pkey(const SSL *s) {
    int i = ssl_get_server_cert_index(s);
  
    /* This may or may not be an error. */
    if (i < 0) {
      return NULL;
    }
  
    /* May be NULL. */
    return &s->cert->pkeys[i];
  }
  
  EVP_PKEY *ssl_get_sign_pkey(SSL *s, const SSL_CIPHER *cipher) {
    uint32_t alg_a = cipher->algorithm_auth;
    CERT *c = s->cert;
    int idx = -1;
  
    if (alg_a & SSL_aRSA) {
      if (c->pkeys[SSL_PKEY_RSA_SIGN].privatekey != NULL) {
        idx = SSL_PKEY_RSA_SIGN;
      } else if (c->pkeys[SSL_PKEY_RSA_ENC].privatekey != NULL) {
        idx = SSL_PKEY_RSA_ENC;
      }
    } else if ((alg_a & SSL_aECDSA) &&
               (c->pkeys[SSL_PKEY_ECC].privatekey != NULL)) {
      idx = SSL_PKEY_ECC;
    }
  
    if (idx == -1) {
      OPENSSL_PUT_ERROR(SSL, ssl_get_sign_pkey, ERR_R_INTERNAL_ERROR);
      return NULL;
    }
  
    return c->pkeys[idx].privatekey;
  }
  
  void ssl_update_cache(SSL *s, int mode) {
    /* Never cache sessions with empty session IDs. */
    if (s->session->session_id_length == 0) {
      return;
    }
  
    int has_new_session = !s->hit;
    if (!s->server && s->tlsext_ticket_expected) {
      /* A client may see new sessions on abbreviated handshakes if the server
       * decides to renew the ticket. Once the handshake is completed, it should
       * be inserted into the cache. */
      has_new_session = 1;
    }
  
    SSL_CTX *ctx = s->initial_ctx;
    if ((ctx->session_cache_mode & mode) == mode && has_new_session &&
        ((ctx->session_cache_mode & SSL_SESS_CACHE_NO_INTERNAL_STORE) ||
         SSL_CTX_add_session(ctx, s->session)) &&
        ctx->new_session_cb != NULL) {
      /* Note: |new_session_cb| is called whether the internal session cache is
       * used or not. */
      if (!ctx->new_session_cb(s, SSL_SESSION_up_ref(s->session))) {
        SSL_SESSION_free(s->session);
      }
    }
  
    if (!(ctx->session_cache_mode & SSL_SESS_CACHE_NO_AUTO_CLEAR) &&
        !(ctx->session_cache_mode & SSL_SESS_CACHE_NO_INTERNAL_STORE) &&
        (ctx->session_cache_mode & mode) == mode) {
      /* Automatically flush the internal session cache every 255 connections. */
      int flush_cache = 0;
      CRYPTO_MUTEX_lock_write(&ctx->lock);
      ctx->handshakes_since_cache_flush++;
      if (ctx->handshakes_since_cache_flush >= 255) {
        flush_cache = 1;
        ctx->handshakes_since_cache_flush = 0;
      }
      CRYPTO_MUTEX_unlock(&ctx->lock);
  
      if (flush_cache) {
        SSL_CTX_flush_sessions(ctx, (unsigned long)time(NULL));
      }
    }
  }
  
  int SSL_get_error(const SSL *s, int ret_code) {
    int reason;
    uint32_t err;
    BIO *bio;
  
    if (ret_code > 0) {
      return SSL_ERROR_NONE;
    }
  
    /* Make things return SSL_ERROR_SYSCALL when doing SSL_do_handshake etc,
     * where we do encode the error */
    err = ERR_peek_error();
    if (err != 0) {
      if (ERR_GET_LIB(err) == ERR_LIB_SYS) {
        return SSL_ERROR_SYSCALL;
      }
      return SSL_ERROR_SSL;
    }
  
    if (ret_code == 0) {
      if ((s->shutdown & SSL_RECEIVED_SHUTDOWN) &&
          (s->s3->warn_alert == SSL_AD_CLOSE_NOTIFY)) {
        /* The socket was cleanly shut down with a close_notify. */
        return SSL_ERROR_ZERO_RETURN;
      }
      /* An EOF was observed which violates the protocol, and the underlying
       * transport does not participate in the error queue. Bubble up to the
       * caller. */
      return SSL_ERROR_SYSCALL;
    }
  
    if (SSL_want_session(s)) {
      return SSL_ERROR_PENDING_SESSION;
    }
  
    if (SSL_want_certificate(s)) {
      return SSL_ERROR_PENDING_CERTIFICATE;
    }
  
    if (SSL_want_read(s)) {
      bio = SSL_get_rbio(s);
      if (BIO_should_read(bio)) {
        return SSL_ERROR_WANT_READ;
      }
  
      if (BIO_should_write(bio)) {
        /* This one doesn't make too much sense ... We never try to write to the
         * rbio, and an application program where rbio and wbio are separate
         * couldn't even know what it should wait for. However if we ever set
         * s->rwstate incorrectly (so that we have SSL_want_read(s) instead of
         * SSL_want_write(s)) and rbio and wbio *are* the same, this test works
         * around that bug; so it might be safer to keep it. */
        return SSL_ERROR_WANT_WRITE;
      }
  
      if (BIO_should_io_special(bio)) {
        reason = BIO_get_retry_reason(bio);
        if (reason == BIO_RR_CONNECT) {
          return SSL_ERROR_WANT_CONNECT;
        }
  
        if (reason == BIO_RR_ACCEPT) {
          return SSL_ERROR_WANT_ACCEPT;
        }
  
        return SSL_ERROR_SYSCALL; /* unknown */
      }
    }
  
    if (SSL_want_write(s)) {
      bio = SSL_get_wbio(s);
      if (BIO_should_write(bio)) {
        return SSL_ERROR_WANT_WRITE;
      }
  
      if (BIO_should_read(bio)) {
        /* See above (SSL_want_read(s) with BIO_should_write(bio)) */
        return SSL_ERROR_WANT_READ;
      }
  
      if (BIO_should_io_special(bio)) {
        reason = BIO_get_retry_reason(bio);
        if (reason == BIO_RR_CONNECT) {
          return SSL_ERROR_WANT_CONNECT;
        }
  
        if (reason == BIO_RR_ACCEPT) {
          return SSL_ERROR_WANT_ACCEPT;
        }
  
        return SSL_ERROR_SYSCALL;
      }
    }
  
    if (SSL_want_x509_lookup(s)) {
      return SSL_ERROR_WANT_X509_LOOKUP;
    }
  
    if (SSL_want_channel_id_lookup(s)) {
      return SSL_ERROR_WANT_CHANNEL_ID_LOOKUP;
    }
  
    if (SSL_want_private_key_operation(s)) {
      return SSL_ERROR_WANT_PRIVATE_KEY_OPERATION;
    }
  
    return SSL_ERROR_SYSCALL;
  }
  
  int SSL_do_handshake(SSL *s) {
    int ret = 1;
  
    if (s->handshake_func == NULL) {
      OPENSSL_PUT_ERROR(SSL, SSL_do_handshake, SSL_R_CONNECTION_TYPE_NOT_SET);
      return -1;
    }
  
    if (SSL_in_init(s)) {
      ret = s->handshake_func(s);
    }
    return ret;
  }
  
  void SSL_set_accept_state(SSL *ssl) {
    ssl->server = 1;
    ssl->shutdown = 0;
    ssl->state = SSL_ST_ACCEPT;
    ssl->handshake_func = ssl->method->ssl_accept;
    /* clear the current cipher */
    ssl_clear_cipher_ctx(ssl);
  }
  
  void SSL_set_connect_state(SSL *ssl) {
    ssl->server = 0;
    ssl->shutdown = 0;
    ssl->state = SSL_ST_CONNECT;
    ssl->handshake_func = ssl->method->ssl_connect;
    /* clear the current cipher */
    ssl_clear_cipher_ctx(ssl);
  }
  
  static const char *ssl_get_version(int version) {
    switch (version) {
      case TLS1_2_VERSION:
        return "TLSv1.2";
  
      case TLS1_1_VERSION:
        return "TLSv1.1";
  
      case TLS1_VERSION:
        return "TLSv1";
  
      case SSL3_VERSION:
        return "SSLv3";
  
      case DTLS1_VERSION:
        return "DTLSv1";
  
      case DTLS1_2_VERSION:
        return "DTLSv1.2";
  
      default:
        return "unknown";
    }
  }
  
  const char *SSL_get_version(const SSL *s) {
    return ssl_get_version(s->version);
  }
  
  const char *SSL_SESSION_get_version(const SSL_SESSION *sess) {
    return ssl_get_version(sess->ssl_version);
  }
  
  void ssl_clear_cipher_ctx(SSL *s) {
    SSL_AEAD_CTX_free(s->aead_read_ctx);
    s->aead_read_ctx = NULL;
    SSL_AEAD_CTX_free(s->aead_write_ctx);
    s->aead_write_ctx = NULL;
  }
  
  X509 *SSL_get_certificate(const SSL *s) {
    if (s->cert != NULL) {
      return s->cert->key->x509;
    }
  
    return NULL;
  }
  
  EVP_PKEY *SSL_get_privatekey(const SSL *s) {
    if (s->cert != NULL) {
      return s->cert->key->privatekey;
    }
  
    return NULL;
  }
  
  X509 *SSL_CTX_get0_certificate(const SSL_CTX *ctx) {
    if (ctx->cert != NULL) {
      return ctx->cert->key->x509;
    }
  
    return NULL;
  }
  
  EVP_PKEY *SSL_CTX_get0_privatekey(const SSL_CTX *ctx) {
    if (ctx->cert != NULL) {
      return ctx->cert->key->privatekey;
    }
  
    return NULL;
  }
  
  const SSL_CIPHER *SSL_get_current_cipher(const SSL *s) {
    if (s->aead_write_ctx == NULL) {
      return NULL;
    }
    return s->aead_write_ctx->cipher;
  }
  
  const void *SSL_get_current_compression(SSL *s) { return NULL; }
  
  const void *SSL_get_current_expansion(SSL *s) { return NULL; }
  
  int ssl_init_wbio_buffer(SSL *s, int push) {
    BIO *bbio;
  
    if (s->bbio == NULL) {
      bbio = BIO_new(BIO_f_buffer());
      if (bbio == NULL) {
        return 0;
      }
      s->bbio = bbio;
    } else {
      bbio = s->bbio;
      if (s->bbio == s->wbio) {
        s->wbio = BIO_pop(s->wbio);
      }
    }
  
    BIO_reset(bbio);
    if (!BIO_set_read_buffer_size(bbio, 1)) {
      OPENSSL_PUT_ERROR(SSL, ssl_init_wbio_buffer, ERR_R_BUF_LIB);
      return 0;
    }
  
    if (push) {
      if (s->wbio != bbio) {
        s->wbio = BIO_push(bbio, s->wbio);
      }
    } else {
      if (s->wbio == bbio) {
        s->wbio = BIO_pop(bbio);
      }
    }
  
    return 1;
  }
  
  void ssl_free_wbio_buffer(SSL *s) {
    if (s->bbio == NULL) {
      return;
    }
  
    if (s->bbio == s->wbio) {
      /* remove buffering */
      s->wbio = BIO_pop(s->wbio);
    }
  
    BIO_free(s->bbio);
    s->bbio = NULL;
  }
  
  void SSL_CTX_set_quiet_shutdown(SSL_CTX *ctx, int mode) {
    ctx->quiet_shutdown = mode;
  }
  
  int SSL_CTX_get_quiet_shutdown(const SSL_CTX *ctx) {
    return ctx->quiet_shutdown;
  }
  
  void SSL_set_quiet_shutdown(SSL *s, int mode) { s->quiet_shutdown = mode; }
  
  int SSL_get_quiet_shutdown(const SSL *s) { return s->quiet_shutdown; }
  
  void SSL_set_shutdown(SSL *s, int mode) { s->shutdown = mode; }
  
  int SSL_get_shutdown(const SSL *s) { return s->shutdown; }
  
  int SSL_version(const SSL *s) { return s->version; }
  
  SSL_CTX *SSL_get_SSL_CTX(const SSL *ssl) { return ssl->ctx; }
  
  SSL_CTX *SSL_set_SSL_CTX(SSL *ssl, SSL_CTX *ctx) {
    if (ssl->ctx == ctx) {
      return ssl->ctx;
    }
  
    if (ctx == NULL) {
      ctx = ssl->initial_ctx;
    }
  
    ssl_cert_free(ssl->cert);
    ssl->cert = ssl_cert_dup(ctx->cert);
  
    CRYPTO_refcount_inc(&ctx->references);
    SSL_CTX_free(ssl->ctx); /* decrement reference count */
    ssl->ctx = ctx;
  
    ssl->sid_ctx_length = ctx->sid_ctx_length;
    assert(ssl->sid_ctx_length <= sizeof(ssl->sid_ctx));
    memcpy(ssl->sid_ctx, ctx->sid_ctx, sizeof(ssl->sid_ctx));
  
    return ssl->ctx;
  }
  
  int SSL_CTX_set_default_verify_paths(SSL_CTX *ctx) {
    return X509_STORE_set_default_paths(ctx->cert_store);
  }
  
  int SSL_CTX_load_verify_locations(SSL_CTX *ctx, const char *CAfile,
                                    const char *CApath) {
    return X509_STORE_load_locations(ctx->cert_store, CAfile, CApath);
  }
  
  void SSL_set_info_callback(SSL *ssl,
                             void (*cb)(const SSL *ssl, int type, int val)) {
    ssl->info_callback = cb;
  }
  
  void (*SSL_get_info_callback(const SSL *ssl))(const SSL * /*ssl*/, int /*type*/,
                                                int /*val*/) {
    return ssl->info_callback;
  }
  
  int SSL_state(const SSL *ssl) { return ssl->state; }
  
  void SSL_set_state(SSL *ssl, int state) { }
  
  void SSL_set_verify_result(SSL *ssl, long arg) { ssl->verify_result = arg; }
  
  long SSL_get_verify_result(const SSL *ssl) { return ssl->verify_result; }
  
  int SSL_get_ex_new_index(long argl, void *argp, CRYPTO_EX_new *new_func,
                           CRYPTO_EX_dup *dup_func, CRYPTO_EX_free *free_func) {
    int index;
    if (!CRYPTO_get_ex_new_index(&g_ex_data_class_ssl, &index, argl, argp,
                                 new_func, dup_func, free_func)) {
      return -1;
    }
    return index;
  }
  
  int SSL_set_ex_data(SSL *s, int idx, void *arg) {
    return CRYPTO_set_ex_data(&s->ex_data, idx, arg);
  }
  
  void *SSL_get_ex_data(const SSL *s, int idx) {
    return CRYPTO_get_ex_data(&s->ex_data, idx);
  }
  
  int SSL_CTX_get_ex_new_index(long argl, void *argp, CRYPTO_EX_new *new_func,
                               CRYPTO_EX_dup *dup_func,
                               CRYPTO_EX_free *free_func) {
    int index;
    if (!CRYPTO_get_ex_new_index(&g_ex_data_class_ssl_ctx, &index, argl, argp,
                                 new_func, dup_func, free_func)) {
      return -1;
    }
    return index;
  }
  
  int SSL_CTX_set_ex_data(SSL_CTX *s, int idx, void *arg) {
    return CRYPTO_set_ex_data(&s->ex_data, idx, arg);
  }
  
  void *SSL_CTX_get_ex_data(const SSL_CTX *s, int idx) {
    return CRYPTO_get_ex_data(&s->ex_data, idx);
  }
  
  X509_STORE *SSL_CTX_get_cert_store(const SSL_CTX *ctx) {
    return ctx->cert_store;
  }
  
  void SSL_CTX_set_cert_store(SSL_CTX *ctx, X509_STORE *store) {
    X509_STORE_free(ctx->cert_store);
    ctx->cert_store = store;
  }
  
  int SSL_want(const SSL *s) { return s->rwstate; }
  
  void SSL_CTX_set_tmp_rsa_callback(SSL_CTX *ctx,
                                    RSA *(*cb)(SSL *ssl, int is_export,
                                               int keylength)) {
  }
  
  void SSL_set_tmp_rsa_callback(SSL *ssl, RSA *(*cb)(SSL *ssl, int is_export,
                                                     int keylength)) {
  }
  
  void SSL_CTX_set_tmp_dh_callback(SSL_CTX *ctx,
                                   DH *(*callback)(SSL *ssl, int is_export,
                                                   int keylength)) {
    ctx->cert->dh_tmp_cb = callback;
  }
  
  void SSL_set_tmp_dh_callback(SSL *ssl, DH *(*callback)(SSL *ssl, int is_export,
                                                         int keylength)) {
    ssl->cert->dh_tmp_cb = callback;
  }
  
  void SSL_CTX_set_tmp_ecdh_callback(SSL_CTX *ctx,
                                     EC_KEY *(*callback)(SSL *ssl, int is_export,
                                                         int keylength)) {
    ctx->cert->ecdh_tmp_cb = callback;
  }
  
  void SSL_set_tmp_ecdh_callback(SSL *ssl,
                                 EC_KEY *(*callback)(SSL *ssl, int is_export,
                                                     int keylength)) {
    ssl->cert->ecdh_tmp_cb = callback;
  }
  
  int SSL_CTX_use_psk_identity_hint(SSL_CTX *ctx, const char *identity_hint) {
    if (identity_hint != NULL && strlen(identity_hint) > PSK_MAX_IDENTITY_LEN) {
      OPENSSL_PUT_ERROR(SSL, SSL_CTX_use_psk_identity_hint,
                        SSL_R_DATA_LENGTH_TOO_LONG);
      return 0;
    }
  
    OPENSSL_free(ctx->psk_identity_hint);
  
    if (identity_hint != NULL) {
      ctx->psk_identity_hint = BUF_strdup(identity_hint);
      if (ctx->psk_identity_hint == NULL) {
        return 0;
      }
    } else {
      ctx->psk_identity_hint = NULL;
    }
  
    return 1;
  }
  
  int SSL_use_psk_identity_hint(SSL *s, const char *identity_hint) {
    if (s == NULL) {
      return 0;
    }
  
    if (identity_hint != NULL && strlen(identity_hint) > PSK_MAX_IDENTITY_LEN) {
      OPENSSL_PUT_ERROR(SSL, SSL_use_psk_identity_hint,
                        SSL_R_DATA_LENGTH_TOO_LONG);
      return 0;
    }
  
    /* Clear currently configured hint, if any. */
    OPENSSL_free(s->psk_identity_hint);
    s->psk_identity_hint = NULL;
  
    if (identity_hint != NULL) {
      s->psk_identity_hint = BUF_strdup(identity_hint);
      if (s->psk_identity_hint == NULL) {
        return 0;
      }
    }
  
    return 1;
  }
  
  const char *SSL_get_psk_identity_hint(const SSL *s) {
    if (s == NULL) {
      return NULL;
    }
    return s->psk_identity_hint;
  }
  
  const char *SSL_get_psk_identity(const SSL *s) {
    if (s == NULL || s->session == NULL) {
      return NULL;
    }
  
    return s->session->psk_identity;
  }
  
  void SSL_set_psk_client_callback(
      SSL *s, unsigned int (*cb)(SSL *ssl, const char *hint, char *identity,
                                 unsigned int max_identity_len, uint8_t *psk,
                                 unsigned int max_psk_len)) {
    s->psk_client_callback = cb;
  }
  
  void SSL_CTX_set_psk_client_callback(
      SSL_CTX *ctx, unsigned int (*cb)(SSL *ssl, const char *hint, char *identity,
                                       unsigned int max_identity_len,
                                       uint8_t *psk, unsigned int max_psk_len)) {
    ctx->psk_client_callback = cb;
  }
  
  void SSL_set_psk_server_callback(
      SSL *s, unsigned int (*cb)(SSL *ssl, const char *identity, uint8_t *psk,
                                 unsigned int max_psk_len)) {
    s->psk_server_callback = cb;
  }
  
  void SSL_CTX_set_psk_server_callback(
      SSL_CTX *ctx, unsigned int (*cb)(SSL *ssl, const char *identity,
                                       uint8_t *psk, unsigned int max_psk_len)) {
    ctx->psk_server_callback = cb;
  }
  
  void SSL_CTX_set_min_version(SSL_CTX *ctx, uint16_t version) {
    ctx->min_version = version;
  }
  
  void SSL_CTX_set_max_version(SSL_CTX *ctx, uint16_t version) {
    ctx->max_version = version;
  }
  
  void SSL_set_min_version(SSL *ssl, uint16_t version) {
    ssl->min_version = version;
  }
  
  void SSL_set_max_version(SSL *ssl, uint16_t version) {
    ssl->max_version = version;
  }
  
  void SSL_CTX_set_msg_callback(SSL_CTX *ctx,
                                void (*cb)(int write_p, int version,
                                           int content_type, const void *buf,
                                           size_t len, SSL *ssl, void *arg)) {
    ctx->msg_callback = cb;
  }
  
  void SSL_CTX_set_msg_callback_arg(SSL_CTX *ctx, void *arg) {
    ctx->msg_callback_arg = arg;
  }
  
  void SSL_set_msg_callback(SSL *ssl,
                            void (*cb)(int write_p, int version, int content_type,
                                       const void *buf, size_t len, SSL *ssl,
                                       void *arg)) {
    ssl->msg_callback = cb;
  }
  
  void SSL_set_msg_callback_arg(SSL *ssl, void *arg) {
    ssl->msg_callback_arg = arg;
  }
  
  void SSL_CTX_set_keylog_bio(SSL_CTX *ctx, BIO *keylog_bio) {
    BIO_free(ctx->keylog_bio);
    ctx->keylog_bio = keylog_bio;
  }
  
  static int cbb_add_hex(CBB *cbb, const uint8_t *in, size_t in_len) {
    static const char hextable[] = "0123456789abcdef";
    uint8_t *out;
    size_t i;
  
    if (!CBB_add_space(cbb, &out, in_len * 2)) {
      return 0;
    }
  
    for (i = 0; i < in_len; i++) {
      *(out++) = (uint8_t)hextable[in[i] >> 4];
      *(out++) = (uint8_t)hextable[in[i] & 0xf];
    }
  
    return 1;
  }
  
  int ssl_ctx_log_rsa_client_key_exchange(SSL_CTX *ctx,
                                          const uint8_t *encrypted_premaster,
                                          size_t encrypted_premaster_len,
                                          const uint8_t *premaster,
                                          size_t premaster_len) {
    BIO *bio = ctx->keylog_bio;
    CBB cbb;
    uint8_t *out;
    size_t out_len;
    int ret;
  
    if (bio == NULL) {
      return 1;
    }
  
    if (encrypted_premaster_len < 8) {
      OPENSSL_PUT_ERROR(SSL, ssl_ctx_log_rsa_client_key_exchange,
                        ERR_R_INTERNAL_ERROR);
      return 0;
    }
  
    if (!CBB_init(&cbb, 4 + 16 + 1 + premaster_len * 2 + 1)) {
      return 0;
    }
  
    if (!CBB_add_bytes(&cbb, (const uint8_t *)"RSA ", 4) ||
        /* Only the first 8 bytes of the encrypted premaster secret are
         * logged. */
        !cbb_add_hex(&cbb, encrypted_premaster, 8) ||
        !CBB_add_bytes(&cbb, (const uint8_t *)" ", 1) ||
        !cbb_add_hex(&cbb, premaster, premaster_len) ||
        !CBB_add_bytes(&cbb, (const uint8_t *)"\n", 1) ||
        !CBB_finish(&cbb, &out, &out_len)) {
      CBB_cleanup(&cbb);
      return 0;
    }
  
    CRYPTO_MUTEX_lock_write(&ctx->lock);
    ret = BIO_write(bio, out, out_len) >= 0 && BIO_flush(bio);
    CRYPTO_MUTEX_unlock(&ctx->lock);
  
    OPENSSL_free(out);
    return ret;
  }
  
  int ssl_ctx_log_master_secret(SSL_CTX *ctx, const uint8_t *client_random,
                                size_t client_random_len, const uint8_t *master,
                                size_t master_len) {
    BIO *bio = ctx->keylog_bio;
    CBB cbb;
    uint8_t *out;
    size_t out_len;
    int ret;
  
    if (bio == NULL) {
      return 1;
    }
  
    if (client_random_len != 32) {
      OPENSSL_PUT_ERROR(SSL, ssl_ctx_log_master_secret, ERR_R_INTERNAL_ERROR);
      return 0;
    }
  
    if (!CBB_init(&cbb, 14 + 64 + 1 + master_len * 2 + 1)) {
      return 0;
    }
  
    if (!CBB_add_bytes(&cbb, (const uint8_t *)"CLIENT_RANDOM ", 14) ||
        !cbb_add_hex(&cbb, client_random, 32) ||
        !CBB_add_bytes(&cbb, (const uint8_t *)" ", 1) ||
        !cbb_add_hex(&cbb, master, master_len) ||
        !CBB_add_bytes(&cbb, (const uint8_t *)"\n", 1) ||
        !CBB_finish(&cbb, &out, &out_len)) {
      CBB_cleanup(&cbb);
      return 0;
    }
  
    CRYPTO_MUTEX_lock_write(&ctx->lock);
    ret = BIO_write(bio, out, out_len) >= 0 && BIO_flush(bio);
    CRYPTO_MUTEX_unlock(&ctx->lock);
  
    OPENSSL_free(out);
    return ret;
  }
  
  int SSL_in_false_start(const SSL *s) {
    return s->s3->tmp.in_false_start;
  }
  
  int SSL_cutthrough_complete(const SSL *s) {
    return SSL_in_false_start(s);
  }
  
  void SSL_get_structure_sizes(size_t *ssl_size, size_t *ssl_ctx_size,
                               size_t *ssl_session_size) {
    *ssl_size = sizeof(SSL);
    *ssl_ctx_size = sizeof(SSL_CTX);
    *ssl_session_size = sizeof(SSL_SESSION);
  }
  
  int ssl3_can_false_start(const SSL *s) {
    const SSL_CIPHER *const cipher = SSL_get_current_cipher(s);
  
    /* False Start only for TLS 1.2 with an ECDHE+AEAD cipher and ALPN or NPN. */
    return !SSL_IS_DTLS(s) &&
        SSL_version(s) >= TLS1_2_VERSION &&
        (s->s3->alpn_selected || s->s3->next_proto_neg_seen) &&
        cipher != NULL &&
        cipher->algorithm_mkey == SSL_kECDHE &&
        (cipher->algorithm_enc == SSL_AES128GCM ||
         cipher->algorithm_enc == SSL_AES256GCM ||
         cipher->algorithm_enc == SSL_CHACHA20POLY1305);
  }
  
  const SSL3_ENC_METHOD *ssl3_get_enc_method(uint16_t version) {
    switch (version) {
      case SSL3_VERSION:
        return &SSLv3_enc_data;
  
      case TLS1_VERSION:
        return &TLSv1_enc_data;
  
      case DTLS1_VERSION:
      case TLS1_1_VERSION:
        return &TLSv1_1_enc_data;
  
      case DTLS1_2_VERSION:
      case TLS1_2_VERSION:
        return &TLSv1_2_enc_data;
  
      default:
        return NULL;
    }
  }
  
  uint16_t ssl3_get_max_server_version(const SSL *s) {
    uint16_t max_version;
  
    if (SSL_IS_DTLS(s)) {
      max_version = (s->max_version != 0) ? s->max_version : DTLS1_2_VERSION;
      if (!(s->options & SSL_OP_NO_DTLSv1_2) && DTLS1_2_VERSION >= max_version) {
        return DTLS1_2_VERSION;
      }
      if (!(s->options & SSL_OP_NO_DTLSv1) && DTLS1_VERSION >= max_version) {
        return DTLS1_VERSION;
      }
      return 0;
    }
  
    max_version = (s->max_version != 0) ? s->max_version : TLS1_2_VERSION;
    if (!(s->options & SSL_OP_NO_TLSv1_2) && TLS1_2_VERSION <= max_version) {
      return TLS1_2_VERSION;
    }
    if (!(s->options & SSL_OP_NO_TLSv1_1) && TLS1_1_VERSION <= max_version) {
      return TLS1_1_VERSION;
    }
    if (!(s->options & SSL_OP_NO_TLSv1) && TLS1_VERSION <= max_version) {
      return TLS1_VERSION;
    }
    if (!(s->options & SSL_OP_NO_SSLv3) && SSL3_VERSION <= max_version) {
      return SSL3_VERSION;
    }
    return 0;
  }
  
  uint16_t ssl3_get_mutual_version(SSL *s, uint16_t client_version) {
    uint16_t version = 0;
  
    if (SSL_IS_DTLS(s)) {
      /* Clamp client_version to max_version. */
      if (s->max_version != 0 && client_version < s->max_version) {
        client_version = s->max_version;
      }
  
      if (client_version <= DTLS1_2_VERSION && !(s->options & SSL_OP_NO_DTLSv1_2)) {
        version = DTLS1_2_VERSION;
      } else if (client_version <= DTLS1_VERSION &&
                 !(s->options & SSL_OP_NO_DTLSv1)) {
        version = DTLS1_VERSION;
      }
  
      /* Check against min_version. */
      if (version != 0 && s->min_version != 0 && version > s->min_version) {
        return 0;
      }
      return version;
    } else {
      /* Clamp client_version to max_version. */
      if (s->max_version != 0 && client_version > s->max_version) {
        client_version = s->max_version;
      }
  
      if (client_version >= TLS1_2_VERSION && !(s->options & SSL_OP_NO_TLSv1_2)) {
        version = TLS1_2_VERSION;
      } else if (client_version >= TLS1_1_VERSION &&
               !(s->options & SSL_OP_NO_TLSv1_1)) {
        version = TLS1_1_VERSION;
      } else if (client_version >= TLS1_VERSION && !(s->options & SSL_OP_NO_TLSv1)) {
        version = TLS1_VERSION;
      } else if (client_version >= SSL3_VERSION && !(s->options & SSL_OP_NO_SSLv3)) {
        version = SSL3_VERSION;
      }
  
      /* Check against min_version. */
      if (version != 0 && s->min_version != 0 && version < s->min_version) {
        return 0;
      }
      return version;
    }
  }
  
  uint16_t ssl3_get_max_client_version(SSL *s) {
    uint32_t options = s->options;
    uint16_t version = 0;
  
    /* OpenSSL's API for controlling versions entails blacklisting individual
     * protocols. This has two problems. First, on the client, the protocol can
     * only express a contiguous range of versions. Second, a library consumer
     * trying to set a maximum version cannot disable protocol versions that get
     * added in a future version of the library.
     *
     * To account for both of these, OpenSSL interprets the client-side bitmask
     * as a min/max range by picking the lowest contiguous non-empty range of
     * enabled protocols. Note that this means it is impossible to set a maximum
     * version of TLS 1.2 in a future-proof way.
     *
     * By this scheme, the maximum version is the lowest version V such that V is
     * enabled and V+1 is disabled or unimplemented. */
    if (SSL_IS_DTLS(s)) {
      if (!(options & SSL_OP_NO_DTLSv1_2)) {
        version = DTLS1_2_VERSION;
      }
      if (!(options & SSL_OP_NO_DTLSv1) && (options & SSL_OP_NO_DTLSv1_2)) {
        version = DTLS1_VERSION;
      }
      if (s->max_version != 0 && version < s->max_version) {
        version = s->max_version;
      }
    } else {
      if (!(options & SSL_OP_NO_TLSv1_2)) {
        version = TLS1_2_VERSION;
      }
      if (!(options & SSL_OP_NO_TLSv1_1) && (options & SSL_OP_NO_TLSv1_2)) {
        version = TLS1_1_VERSION;
      }
      if (!(options & SSL_OP_NO_TLSv1) && (options & SSL_OP_NO_TLSv1_1)) {
        version = TLS1_VERSION;
      }
      if (!(options & SSL_OP_NO_SSLv3) && (options & SSL_OP_NO_TLSv1)) {
        version = SSL3_VERSION;
      }
      if (s->max_version != 0 && version > s->max_version) {
        version = s->max_version;
      }
    }
  
    return version;
  }
  
  int ssl3_is_version_enabled(SSL *s, uint16_t version) {
    if (SSL_IS_DTLS(s)) {
      if (s->max_version != 0 && version < s->max_version) {
        return 0;
      }
      if (s->min_version != 0 && version > s->min_version) {
        return 0;
      }
  
      switch (version) {
        case DTLS1_VERSION:
          return !(s->options & SSL_OP_NO_DTLSv1);
  
        case DTLS1_2_VERSION:
          return !(s->options & SSL_OP_NO_DTLSv1_2);
  
        default:
          return 0;
      }
    } else {
      if (s->max_version != 0 && version > s->max_version) {
        return 0;
      }
      if (s->min_version != 0 && version < s->min_version) {
        return 0;
      }
  
      switch (version) {
        case SSL3_VERSION:
          return !(s->options & SSL_OP_NO_SSLv3);
  
        case TLS1_VERSION:
          return !(s->options & SSL_OP_NO_TLSv1);
  
        case TLS1_1_VERSION:
          return !(s->options & SSL_OP_NO_TLSv1_1);
  
        case TLS1_2_VERSION:
          return !(s->options & SSL_OP_NO_TLSv1_2);
  
        default:
          return 0;
      }
    }
  }
  
  uint16_t ssl3_version_from_wire(SSL *s, uint16_t wire_version) {
    if (!SSL_IS_DTLS(s)) {
      return wire_version;
    }
  
    uint16_t tls_version = ~wire_version;
    uint16_t version = tls_version + 0x0201;
    /* If either component overflowed, clamp it so comparisons still work. */
    if ((version >> 8) < (tls_version >> 8)) {
      version = 0xff00 | (version & 0xff);
    }
    if ((version & 0xff) < (tls_version & 0xff)) {
      version = (version & 0xff00) | 0xff;
    }
    /* DTLS 1.0 maps to TLS 1.1, not TLS 1.0. */
    if (version == TLS1_VERSION) {
      version = TLS1_1_VERSION;
    }
    return version;
  }
  
  int SSL_cache_hit(SSL *s) { return s->hit; }
  
  int SSL_is_server(SSL *s) { return s->server; }
  
  void SSL_CTX_set_dos_protection_cb(
      SSL_CTX *ctx, int (*cb)(const struct ssl_early_callback_ctx *)) {
    ctx->dos_protection_cb = cb;
  }
  
  void SSL_enable_fastradio_padding(SSL *s, char on_off) {
    s->fastradio_padding = on_off;
  }
  
  void SSL_set_reject_peer_renegotiations(SSL *s, int reject) {
    s->accept_peer_renegotiations = !reject;
  }
  
  int SSL_get_rc4_state(const SSL *ssl, const RC4_KEY **read_key,
                        const RC4_KEY **write_key) {
    if (ssl->aead_read_ctx == NULL || ssl->aead_write_ctx == NULL) {
      return 0;
    }
  
    return EVP_AEAD_CTX_get_rc4_state(&ssl->aead_read_ctx->ctx, read_key) &&
           EVP_AEAD_CTX_get_rc4_state(&ssl->aead_write_ctx->ctx, write_key);
  }
  
  int SSL_get_tls_unique(const SSL *ssl, uint8_t *out, size_t *out_len,
                         size_t max_out) {
    /* The tls-unique value is the first Finished message in the handshake, which
     * is the client's in a full handshake and the server's for a resumption. See
     * https://tools.ietf.org/html/rfc5929#section-3.1. */
    const uint8_t *finished = ssl->s3->previous_client_finished;
    size_t finished_len = ssl->s3->previous_client_finished_len;
    if (ssl->hit) {
      /* tls-unique is broken for resumed sessions unless EMS is used. */
      if (!ssl->session->extended_master_secret) {
        goto err;
      }
      finished = ssl->s3->previous_server_finished;
      finished_len = ssl->s3->previous_server_finished_len;
    }
  
    if (!ssl->s3->initial_handshake_complete ||
        ssl->version < TLS1_VERSION) {
      goto err;
    }
  
    *out_len = finished_len;
    if (finished_len > max_out) {
      *out_len = max_out;
    }
  
    memcpy(out, finished, *out_len);
    return 1;
  
  err:
    *out_len = 0;
    memset(out, 0, max_out);
    return 0;
  }
  
  int SSL_CTX_sess_connect(const SSL_CTX *ctx) { return 0; }
  int SSL_CTX_sess_connect_good(const SSL_CTX *ctx) { return 0; }
  int SSL_CTX_sess_connect_renegotiate(const SSL_CTX *ctx) { return 0; }
  int SSL_CTX_sess_accept(const SSL_CTX *ctx) { return 0; }
  int SSL_CTX_sess_accept_renegotiate(const SSL_CTX *ctx) { return 0; }
  int SSL_CTX_sess_accept_good(const SSL_CTX *ctx) { return 0; }
  int SSL_CTX_sess_hits(const SSL_CTX *ctx) { return 0; }
  int SSL_CTX_sess_cb_hits(const SSL_CTX *ctx) { return 0; }
  int SSL_CTX_sess_misses(const SSL_CTX *ctx) { return 0; }
  int SSL_CTX_sess_timeouts(const SSL_CTX *ctx) { return 0; }
  int SSL_CTX_sess_cache_full(const SSL_CTX *ctx) { return 0; }
  