text: /*
   * ! \file ssl/ssl_lib.c \brief Version independent SSL functions.
   */
  /* 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.
   */
  
  #ifdef REF_CHECK
  # include <assert.h>
  #endif
  #include <stdio.h>
  #include "ssl_locl.h"
  #include "kssl_lcl.h"
  #include <openssl/objects.h>
  #include <openssl/lhash.h>
  #include <openssl/x509v3.h>
  #include <openssl/rand.h>
  #include <openssl/ocsp.h>
  #ifndef OPENSSL_NO_DH
  # include <openssl/dh.h>
  #endif
  #ifndef OPENSSL_NO_ENGINE
  # include <openssl/engine.h>
  #endif
  
  const char *SSL_version_str = OPENSSL_VERSION_TEXT;
  
  SSL3_ENC_METHOD ssl3_undef_enc_method = {
      /*
       * evil casts, but these functions are only called if there's a library
       * bug
       */
      (int (*)(SSL *, int))ssl_undefined_function,
      (int (*)(SSL *, unsigned char *, int))ssl_undefined_function,
      ssl_undefined_function,
      (int (*)(SSL *, unsigned char *, unsigned char *, int))
          ssl_undefined_function,
      (int (*)(SSL *, int))ssl_undefined_function,
      (int (*)(SSL *, const char *, int, unsigned char *))
          ssl_undefined_function,
      0,                          /* finish_mac_length */
      (int (*)(SSL *, int, unsigned char *))ssl_undefined_function,
      NULL,                       /* client_finished_label */
      0,                          /* client_finished_label_len */
      NULL,                       /* server_finished_label */
      0,                          /* server_finished_label_len */
      (int (*)(int))ssl_undefined_function,
      (int (*)(SSL *, unsigned char *, size_t, const char *,
               size_t, const unsigned char *, size_t,
               int use_context))ssl_undefined_function,
  };
  
  int SSL_clear(SSL *s)
  {
  
      if (s->method == NULL) {
          SSLerr(SSL_F_SSL_CLEAR, SSL_R_NO_METHOD_SPECIFIED);
          return (0);
      }
  
      if (ssl_clear_bad_session(s)) {
          SSL_SESSION_free(s->session);
          s->session = NULL;
      }
  
      s->error = 0;
      s->hit = 0;
      s->shutdown = 0;
  
  #if 0
      /*
       * Disabled since version 1.10 of this file (early return not
       * needed because SSL_clear is not called when doing renegotiation)
       */
      /*
       * This is set if we are doing dynamic renegotiation so keep
       * the old cipher.  It is sort of a SSL_clear_lite :-)
       */
      if (s->renegotiate)
          return (1);
  #else
      if (s->renegotiate) {
          SSLerr(SSL_F_SSL_CLEAR, ERR_R_INTERNAL_ERROR);
          return 0;
      }
  #endif
  
      s->type = 0;
  
      s->state = SSL_ST_BEFORE | ((s->server) ? SSL_ST_ACCEPT : SSL_ST_CONNECT);
  
      s->version = s->method->version;
      s->client_version = s->version;
      s->rwstate = SSL_NOTHING;
      s->rstate = SSL_ST_READ_HEADER;
  #if 0
      s->read_ahead = s->ctx->read_ahead;
  #endif
  
      if (s->init_buf != NULL) {
          BUF_MEM_free(s->init_buf);
          s->init_buf = NULL;
      }
  
      ssl_clear_cipher_ctx(s);
      ssl_clear_hash_ctx(&s->read_hash);
      ssl_clear_hash_ctx(&s->write_hash);
  
      s->first_packet = 0;
  #ifndef OPENSSL_NO_TLSEXT
      if (s->cert != NULL) {
          if (s->cert->alpn_proposed) {
              OPENSSL_free(s->cert->alpn_proposed);
              s->cert->alpn_proposed = NULL;
          }
          s->cert->alpn_proposed_len = 0;
          s->cert->alpn_sent = 0;
      }
  #endif
  #if 1
      /*
       * Check to see if we were changed into a different method, if so, revert
       * back if we are not doing session-id reuse.
       */
      if (!s->in_handshake && (s->session == NULL)
          && (s->method != s->ctx->method)) {
          s->method->ssl_free(s);
          s->method = s->ctx->method;
          if (!s->method->ssl_new(s))
              return (0);
      } else
  #endif
          s->method->ssl_clear(s);
      return (1);
  }
  
  /** Used to change an SSL_CTXs default SSL method type */
  int SSL_CTX_set_ssl_version(SSL_CTX *ctx, const SSL_METHOD *meth)
  {
      STACK_OF(SSL_CIPHER) *sk;
  
      ctx->method = meth;
  
      sk = ssl_create_cipher_list(ctx->method, &(ctx->cipher_list),
                                  &(ctx->cipher_list_by_id),
                                  meth->version ==
                                  SSL2_VERSION ? "SSLv2" :
                                  SSL_DEFAULT_CIPHER_LIST, ctx->cert);
      if ((sk == NULL) || (sk_SSL_CIPHER_num(sk) <= 0)) {
          SSLerr(SSL_F_SSL_CTX_SET_SSL_VERSION,
                 SSL_R_SSL_LIBRARY_HAS_NO_CIPHERS);
          return (0);
      }
      return (1);
  }
  
  SSL *SSL_new(SSL_CTX *ctx)
  {
      SSL *s;
  
      if (ctx == NULL) {
          SSLerr(SSL_F_SSL_NEW, SSL_R_NULL_SSL_CTX);
          return (NULL);
      }
      if (ctx->method == NULL) {
          SSLerr(SSL_F_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));
  
  #ifndef OPENSSL_NO_KRB5
      s->kssl_ctx = kssl_ctx_new();
  #endif                          /* OPENSSL_NO_KRB5 */
  
      s->options = ctx->options;
      s->mode = ctx->mode;
      s->max_cert_list = ctx->max_cert_list;
      s->references = 1;
  
      if (ctx->cert != NULL) {
          /*
           * Earlier library versions used to copy the pointer to the CERT, not
           * its contents; only when setting new parameters for the per-SSL
           * copy, ssl_cert_new would be called (and the direct reference to
           * the per-SSL_CTX settings would be lost, but those still were
           * indirectly accessed for various purposes, and for that reason they
           * used to be known as s->ctx->default_cert). Now we don't look at the
           * SSL_CTX's CERT after having duplicated it once.
           */
  
          s->cert = ssl_cert_dup(ctx->cert);
          if (s->cert == NULL)
              goto err;
      } else
          s->cert = NULL;         /* Cannot really happen (see SSL_CTX_new) */
  
      s->read_ahead = ctx->read_ahead;
      s->msg_callback = ctx->msg_callback;
      s->msg_callback_arg = ctx->msg_callback_arg;
      s->verify_mode = ctx->verify_mode;
  #if 0
      s->verify_depth = ctx->verify_depth;
  #endif
      s->sid_ctx_length = ctx->sid_ctx_length;
      OPENSSL_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);
  #if 0
      s->purpose = ctx->purpose;
      s->trust = ctx->trust;
  #endif
      s->quiet_shutdown = ctx->quiet_shutdown;
      s->max_send_fragment = ctx->max_send_fragment;
  
      CRYPTO_add(&ctx->references, 1, CRYPTO_LOCK_SSL_CTX);
      s->ctx = ctx;
  #ifndef OPENSSL_NO_TLSEXT
      s->tlsext_debug_cb = 0;
      s->tlsext_debug_arg = NULL;
      s->tlsext_ticket_expected = 0;
      s->tlsext_status_type = -1;
      s->tlsext_status_expected = 0;
      s->tlsext_ocsp_ids = NULL;
      s->tlsext_ocsp_exts = NULL;
      s->tlsext_ocsp_resp = NULL;
      s->tlsext_ocsp_resplen = -1;
      CRYPTO_add(&ctx->references, 1, CRYPTO_LOCK_SSL_CTX);
      s->initial_ctx = ctx;
  # ifndef OPENSSL_NO_EC
      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);
          if (!s->tlsext_ellipticcurvelist)
              goto err;
          s->tlsext_ellipticcurvelist_length =
              ctx->tlsext_ellipticcurvelist_length;
      }
  # endif
  # ifndef OPENSSL_NO_NEXTPROTONEG
      s->next_proto_negotiated = NULL;
  # endif
  
      if (s->ctx->alpn_client_proto_list) {
          s->alpn_client_proto_list =
              OPENSSL_malloc(s->ctx->alpn_client_proto_list_len);
          if (s->alpn_client_proto_list == NULL)
              goto err;
          memcpy(s->alpn_client_proto_list, s->ctx->alpn_client_proto_list,
                 s->ctx->alpn_client_proto_list_len);
          s->alpn_client_proto_list_len = s->ctx->alpn_client_proto_list_len;
      }
  #endif
  
      s->verify_result = X509_V_OK;
  
      s->method = ctx->method;
  
      if (!s->method->ssl_new(s))
          goto err;
  
      s->server = (ctx->method->ssl_accept == ssl_undefined_function) ? 0 : 1;
  
      SSL_clear(s);
  
      CRYPTO_new_ex_data(CRYPTO_EX_INDEX_SSL, s, &s->ex_data);
  
  #ifndef OPENSSL_NO_PSK
      s->psk_client_callback = ctx->psk_client_callback;
      s->psk_server_callback = ctx->psk_server_callback;
  #endif
  
      return (s);
   err:
      if (s != NULL)
          SSL_free(s);
      SSLerr(SSL_F_SSL_NEW, ERR_R_MALLOC_FAILURE);
      return (NULL);
  }
  
  int SSL_CTX_set_session_id_context(SSL_CTX *ctx, const unsigned char *sid_ctx,
                                     unsigned int sid_ctx_len)
  {
      if (sid_ctx_len > sizeof ctx->sid_ctx) {
          SSLerr(SSL_F_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 unsigned char *sid_ctx,
                                 unsigned int sid_ctx_len)
  {
      if (sid_ctx_len > SSL_MAX_SID_CTX_LENGTH) {
          SSLerr(SSL_F_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)
  {
      CRYPTO_w_lock(CRYPTO_LOCK_SSL_CTX);
      ctx->generate_session_id = cb;
      CRYPTO_w_unlock(CRYPTO_LOCK_SSL_CTX);
      return 1;
  }
  
  int SSL_set_generate_session_id(SSL *ssl, GEN_SESSION_CB cb)
  {
      CRYPTO_w_lock(CRYPTO_LOCK_SSL);
      ssl->generate_session_id = cb;
      CRYPTO_w_unlock(CRYPTO_LOCK_SSL);
      return 1;
  }
  
  int SSL_has_matching_session_id(const SSL *ssl, const unsigned char *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);
      /*
       * NB: SSLv2 always uses a fixed 16-byte session ID, so even if a
       * callback is calling us to check the uniqueness of a shorter ID, it
       * must be compared as a padded-out ID because that is what it will be
       * converted to when the callback has finished choosing it.
       */
      if ((r.ssl_version == SSL2_VERSION) &&
          (id_len < SSL2_SSL_SESSION_ID_LENGTH)) {
          memset(r.session_id + id_len, 0, SSL2_SSL_SESSION_ID_LENGTH - id_len);
          r.session_id_length = SSL2_SSL_SESSION_ID_LENGTH;
      }
  
      CRYPTO_r_lock(CRYPTO_LOCK_SSL_CTX);
      p = lh_SSL_SESSION_retrieve(ssl->ctx->sessions, &r);
      CRYPTO_r_unlock(CRYPTO_LOCK_SSL_CTX);
      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);
  }
  
  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 *s)
  {
      int i;
  
      if (s == NULL)
          return;
  
      i = CRYPTO_add(&s->references, -1, CRYPTO_LOCK_SSL);
  #ifdef REF_PRINT
      REF_PRINT("SSL", s);
  #endif
      if (i > 0)
          return;
  #ifdef REF_CHECK
      if (i < 0) {
          fprintf(stderr, "SSL_free, bad reference count\n");
          abort();                /* ok */
      }
  #endif
  
      if (s->param)
          X509_VERIFY_PARAM_free(s->param);
  
      CRYPTO_free_ex_data(CRYPTO_EX_INDEX_SSL, s, &s->ex_data);
  
      if (s->bbio != NULL) {
          /* If the buffering BIO is in place, pop it off */
          if (s->bbio == s->wbio) {
              s->wbio = BIO_pop(s->wbio);
          }
          BIO_free(s->bbio);
          s->bbio = NULL;
      }
      if (s->rbio != NULL)
          BIO_free_all(s->rbio);
      if ((s->wbio != NULL) && (s->wbio != s->rbio))
          BIO_free_all(s->wbio);
  
      if (s->init_buf != NULL)
          BUF_MEM_free(s->init_buf);
  
      /* add extra stuff */
      if (s->cipher_list != NULL)
          sk_SSL_CIPHER_free(s->cipher_list);
      if (s->cipher_list_by_id != NULL)
          sk_SSL_CIPHER_free(s->cipher_list_by_id);
  
      /* Make the next call work :-) */
      if (s->session != NULL) {
          ssl_clear_bad_session(s);
          SSL_SESSION_free(s->session);
      }
  
      ssl_clear_cipher_ctx(s);
      ssl_clear_hash_ctx(&s->read_hash);
      ssl_clear_hash_ctx(&s->write_hash);
  
      if (s->cert != NULL)
          ssl_cert_free(s->cert);
      /* Free up if allocated */
  
  #ifndef OPENSSL_NO_TLSEXT
      if (s->tlsext_hostname)
          OPENSSL_free(s->tlsext_hostname);
      if (s->initial_ctx)
          SSL_CTX_free(s->initial_ctx);
  # ifndef OPENSSL_NO_EC
      if (s->tlsext_ecpointformatlist)
          OPENSSL_free(s->tlsext_ecpointformatlist);
      if (s->tlsext_ellipticcurvelist)
          OPENSSL_free(s->tlsext_ellipticcurvelist);
  # endif                         /* OPENSSL_NO_EC */
      if (s->tlsext_opaque_prf_input)
          OPENSSL_free(s->tlsext_opaque_prf_input);
      if (s->tlsext_ocsp_exts)
          sk_X509_EXTENSION_pop_free(s->tlsext_ocsp_exts, X509_EXTENSION_free);
      if (s->tlsext_ocsp_ids)
          sk_OCSP_RESPID_pop_free(s->tlsext_ocsp_ids, OCSP_RESPID_free);
      if (s->tlsext_ocsp_resp)
          OPENSSL_free(s->tlsext_ocsp_resp);
      if (s->alpn_client_proto_list)
          OPENSSL_free(s->alpn_client_proto_list);
  #endif
  
      if (s->client_CA != NULL)
          sk_X509_NAME_pop_free(s->client_CA, X509_NAME_free);
  
      if (s->method != NULL)
          s->method->ssl_free(s);
  
      if (s->ctx)
          SSL_CTX_free(s->ctx);
  
  #ifndef OPENSSL_NO_KRB5
      if (s->kssl_ctx != NULL)
          kssl_ctx_free(s->kssl_ctx);
  #endif                          /* OPENSSL_NO_KRB5 */
  
  #if !defined(OPENSSL_NO_TLSEXT) && !defined(OPENSSL_NO_NEXTPROTONEG)
      if (s->next_proto_negotiated)
          OPENSSL_free(s->next_proto_negotiated);
  #endif
  
  #ifndef OPENSSL_NO_SRTP
      if (s->srtp_profiles)
          sk_SRTP_PROTECTION_PROFILE_free(s->srtp_profiles);
  #endif
  
      OPENSSL_free(s);
  }
  
  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 != NULL) && (s->rbio != rbio))
          BIO_free_all(s->rbio);
      if ((s->wbio != NULL) && (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);
  }
  
  #ifndef OPENSSL_NO_SOCK
  int SSL_set_fd(SSL *s, int fd)
  {
      int ret = 0;
      BIO *bio = NULL;
  
      bio = BIO_new(BIO_s_socket());
  
      if (bio == NULL) {
          SSLerr(SSL_F_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_SOCKET)
          || ((int)BIO_get_fd(s->rbio, NULL) != fd)) {
          bio = BIO_new(BIO_s_socket());
  
          if (bio == NULL) {
              SSLerr(SSL_F_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_SOCKET)
          || ((int)BIO_get_fd(s->wbio, NULL) != fd)) {
          bio = BIO_new(BIO_s_socket());
  
          if (bio == NULL) {
              SSLerr(SSL_F_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);
  }
  #endif
  
  /* 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);
  }
  
  void SSL_set_read_ahead(SSL *s, int yes)
  {
      s->read_ahead = yes;
  }
  
  int SSL_get_read_ahead(const SSL *s)
  {
      return (s->read_ahead);
  }
  
  int SSL_pending(const SSL *s)
  {
      /*
       * SSL_pending cannot work properly if read-ahead is enabled
       * (SSL_[CTX_]ctrl(..., SSL_CTRL_SET_READ_AHEAD, 1, NULL)), and it is
       * impossible to fix since SSL_pending cannot report errors that may be
       * observed while scanning the new data. (Note that SSL_pending() is
       * often used as a boolean value, so we'd better not return -1.)
       */
      return (s->method->ssl_pending(s));
  }
  
  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 (r);
  
      CRYPTO_add(&r->references, 1, CRYPTO_LOCK_X509);
  
      return (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);
  }
  
  /*
   * Now in theory, since the calling process own 't' it should be safe to
   * modify.  We need to be able to read f without being hassled
   */
  void SSL_copy_session_id(SSL *t, const SSL *f)
  {
      CERT *tmp;
  
      /* Do we need to to SSL locking? */
      SSL_set_session(t, SSL_get_session(f));
  
      /*
       * what if we are setup as SSLv2 but want to talk SSLv3 or vice-versa
       */
      if (t->method != f->method) {
          t->method->ssl_free(t); /* cleanup current */
          t->method = f->method;  /* change method */
          t->method->ssl_new(t);  /* setup new */
      }
  
      tmp = t->cert;
      if (f->cert != NULL) {
          CRYPTO_add(&f->cert->references, 1, CRYPTO_LOCK_SSL_CERT);
          t->cert = f->cert;
      } else
          t->cert = NULL;
      if (tmp != NULL)
          ssl_cert_free(tmp);
      SSL_set_session_id_context(t, f->sid_ctx, f->sid_ctx_length);
  }
  
  /* 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)) {
          SSLerr(SSL_F_SSL_CTX_CHECK_PRIVATE_KEY,
                 SSL_R_NO_CERTIFICATE_ASSIGNED);
          return (0);
      }
      if (ctx->cert->key->privatekey == NULL) {
          SSLerr(SSL_F_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) {
          SSLerr(SSL_F_SSL_CHECK_PRIVATE_KEY, ERR_R_PASSED_NULL_PARAMETER);
          return (0);
      }
      if (ssl->cert == NULL) {
          SSLerr(SSL_F_SSL_CHECK_PRIVATE_KEY, SSL_R_NO_CERTIFICATE_ASSIGNED);
          return 0;
      }
      if (ssl->cert->key->x509 == NULL) {
          SSLerr(SSL_F_SSL_CHECK_PRIVATE_KEY, SSL_R_NO_CERTIFICATE_ASSIGNED);
          return (0);
      }
      if (ssl->cert->key->privatekey == NULL) {
          SSLerr(SSL_F_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);
  
      return (s->method->ssl_accept(s));
  }
  
  int SSL_connect(SSL *s)
  {
      if (s->handshake_func == 0)
          /* Not properly initialized yet */
          SSL_set_connect_state(s);
  
      return (s->method->ssl_connect(s));
  }
  
  long SSL_get_default_timeout(const SSL *s)
  {
      return (s->method->get_timeout());
  }
  
  int SSL_read(SSL *s, void *buf, int num)
  {
      if (s->handshake_func == 0) {
          SSLerr(SSL_F_SSL_READ, SSL_R_UNINITIALIZED);
          return -1;
      }
  
      if (s->shutdown & SSL_RECEIVED_SHUTDOWN) {
          s->rwstate = SSL_NOTHING;
          return (0);
      }
      return (s->method->ssl_read(s, buf, num));
  }
  
  int SSL_peek(SSL *s, void *buf, int num)
  {
      if (s->handshake_func == 0) {
          SSLerr(SSL_F_SSL_PEEK, SSL_R_UNINITIALIZED);
          return -1;
      }
  
      if (s->shutdown & SSL_RECEIVED_SHUTDOWN) {
          return (0);
      }
      return (s->method->ssl_peek(s, buf, num));
  }
  
  int SSL_write(SSL *s, const void *buf, int num)
  {
      if (s->handshake_func == 0) {
          SSLerr(SSL_F_SSL_WRITE, SSL_R_UNINITIALIZED);
          return -1;
      }
  
      if (s->shutdown & SSL_SENT_SHUTDOWN) {
          s->rwstate = SSL_NOTHING;
          SSLerr(SSL_F_SSL_WRITE, SSL_R_PROTOCOL_IS_SHUTDOWN);
          return (-1);
      }
      return (s->method->ssl_write(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) {
          SSLerr(SSL_F_SSL_SHUTDOWN, SSL_R_UNINITIALIZED);
          return -1;
      }
  
      if (!SSL_in_init(s)) {
          return s->method->ssl_shutdown(s);
      } else {
          SSLerr(SSL_F_SSL_SHUTDOWN, SSL_R_SHUTDOWN_WHILE_IN_INIT);
          return -1;
      }
  }
  
  int SSL_renegotiate(SSL *s)
  {
      if (s->renegotiate == 0)
          s->renegotiate = 1;
  
      s->new_session = 1;
  
      return (s->method->ssl_renegotiate(s));
  }
  
  int SSL_renegotiate_abbreviated(SSL *s)
  {
      if (s->renegotiate == 0)
          s->renegotiate = 1;
  
      s->new_session = 0;
  
      return (s->method->ssl_renegotiate(s));
  }
  
  int SSL_renegotiate_pending(SSL *s)
  {
      /*
       * becomes true when negotiation is requested; false again once a
       * handshake has finished
       */
      return (s->renegotiate != 0);
  }
  
  long SSL_ctrl(SSL *s, int cmd, long larg, void *parg)
  {
      long l;
  
      switch (cmd) {
      case SSL_CTRL_GET_READ_AHEAD:
          return (s->read_ahead);
      case SSL_CTRL_SET_READ_AHEAD:
          l = s->read_ahead;
          s->read_ahead = larg;
          return (l);
  
      case SSL_CTRL_SET_MSG_CALLBACK_ARG:
          s->msg_callback_arg = parg;
          return 1;
  
      case SSL_CTRL_OPTIONS:
          return (s->options |= larg);
      case SSL_CTRL_CLEAR_OPTIONS:
          return (s->options &= ~larg);
      case SSL_CTRL_MODE:
          return (s->mode |= larg);
      case SSL_CTRL_CLEAR_MODE:
          return (s->mode &= ~larg);
      case SSL_CTRL_GET_MAX_CERT_LIST:
          return (s->max_cert_list);
      case SSL_CTRL_SET_MAX_CERT_LIST:
          l = s->max_cert_list;
          s->max_cert_list = larg;
          return (l);
      case SSL_CTRL_SET_MAX_SEND_FRAGMENT:
          if (larg < 512 || larg > SSL3_RT_MAX_PLAIN_LENGTH)
              return 0;
          s->max_send_fragment = larg;
          return 1;
      case SSL_CTRL_GET_RI_SUPPORT:
          if (s->s3)
              return s->s3->send_connection_binding;
          else
              return 0;
      case SSL_CTRL_CERT_FLAGS:
          return (s->cert->cert_flags |= larg);
      case SSL_CTRL_CLEAR_CERT_FLAGS:
          return (s->cert->cert_flags &= ~larg);
  
      case SSL_CTRL_GET_RAW_CIPHERLIST:
          if (parg) {
              if (s->cert->ciphers_raw == NULL)
                  return 0;
              *(unsigned char **)parg = s->cert->ciphers_raw;
              return (int)s->cert->ciphers_rawlen;
          } else
              return ssl_put_cipher_by_char(s, NULL, NULL);
      default:
          return (s->method->ssl_ctrl(s, cmd, larg, parg));
      }
  }
  
  long SSL_callback_ctrl(SSL *s, int cmd, void (*fp) (void))
  {
      switch (cmd) {
      case SSL_CTRL_SET_MSG_CALLBACK:
          s->msg_callback = (void (*)
                             (int write_p, int version, int content_type,
                              const void *buf, size_t len, SSL *ssl,
                              void *arg))(fp);
          return 1;
  
      default:
          return (s->method->ssl_callback_ctrl(s, cmd, fp));
      }
  }
  
  LHASH_OF(SSL_SESSION) *SSL_CTX_sessions(SSL_CTX *ctx)
  {
      return ctx->sessions;
  }
  
  long SSL_CTX_ctrl(SSL_CTX *ctx, int cmd, long larg, void *parg)
  {
      long l;
      /* For some cases with ctx == NULL perform syntax checks */
      if (ctx == NULL) {
          switch (cmd) {
  #ifndef OPENSSL_NO_EC
          case SSL_CTRL_SET_CURVES_LIST:
              return tls1_set_curves_list(NULL, NULL, parg);
  #endif
          case SSL_CTRL_SET_SIGALGS_LIST:
          case SSL_CTRL_SET_CLIENT_SIGALGS_LIST:
              return tls1_set_sigalgs_list(NULL, parg, 0);
          default:
              return 0;
          }
      }
  
      switch (cmd) {
      case SSL_CTRL_GET_READ_AHEAD:
          return (ctx->read_ahead);
      case SSL_CTRL_SET_READ_AHEAD:
          l = ctx->read_ahead;
          ctx->read_ahead = larg;
          return (l);
  
      case SSL_CTRL_SET_MSG_CALLBACK_ARG:
          ctx->msg_callback_arg = parg;
          return 1;
  
      case SSL_CTRL_GET_MAX_CERT_LIST:
          return (ctx->max_cert_list);
      case SSL_CTRL_SET_MAX_CERT_LIST:
          l = ctx->max_cert_list;
          ctx->max_cert_list = larg;
          return (l);
  
      case SSL_CTRL_SET_SESS_CACHE_SIZE:
          l = ctx->session_cache_size;
          ctx->session_cache_size = larg;
          return (l);
      case SSL_CTRL_GET_SESS_CACHE_SIZE:
          return (ctx->session_cache_size);
      case SSL_CTRL_SET_SESS_CACHE_MODE:
          l = ctx->session_cache_mode;
          ctx->session_cache_mode = larg;
          return (l);
      case SSL_CTRL_GET_SESS_CACHE_MODE:
          return (ctx->session_cache_mode);
  
      case SSL_CTRL_SESS_NUMBER:
          return (lh_SSL_SESSION_num_items(ctx->sessions));
      case SSL_CTRL_SESS_CONNECT:
          return (ctx->stats.sess_connect);
      case SSL_CTRL_SESS_CONNECT_GOOD:
          return (ctx->stats.sess_connect_good);
      case SSL_CTRL_SESS_CONNECT_RENEGOTIATE:
          return (ctx->stats.sess_connect_renegotiate);
      case SSL_CTRL_SESS_ACCEPT:
          return (ctx->stats.sess_accept);
      case SSL_CTRL_SESS_ACCEPT_GOOD:
          return (ctx->stats.sess_accept_good);
      case SSL_CTRL_SESS_ACCEPT_RENEGOTIATE:
          return (ctx->stats.sess_accept_renegotiate);
      case SSL_CTRL_SESS_HIT:
          return (ctx->stats.sess_hit);
      case SSL_CTRL_SESS_CB_HIT:
          return (ctx->stats.sess_cb_hit);
      case SSL_CTRL_SESS_MISSES:
          return (ctx->stats.sess_miss);
      case SSL_CTRL_SESS_TIMEOUTS:
          return (ctx->stats.sess_timeout);
      case SSL_CTRL_SESS_CACHE_FULL:
          return (ctx->stats.sess_cache_full);
      case SSL_CTRL_OPTIONS:
          return (ctx->options |= larg);
      case SSL_CTRL_CLEAR_OPTIONS:
          return (ctx->options &= ~larg);
      case SSL_CTRL_MODE:
          return (ctx->mode |= larg);
      case SSL_CTRL_CLEAR_MODE:
          return (ctx->mode &= ~larg);
      case SSL_CTRL_SET_MAX_SEND_FRAGMENT:
          if (larg < 512 || larg > SSL3_RT_MAX_PLAIN_LENGTH)
              return 0;
          ctx->max_send_fragment = larg;
          return 1;
      case SSL_CTRL_CERT_FLAGS:
          return (ctx->cert->cert_flags |= larg);
      case SSL_CTRL_CLEAR_CERT_FLAGS:
          return (ctx->cert->cert_flags &= ~larg);
      default:
          return (ctx->method->ssl_ctx_ctrl(ctx, cmd, larg, parg));
      }
  }
  
  long SSL_CTX_callback_ctrl(SSL_CTX *ctx, int cmd, void (*fp) (void))
  {
      switch (cmd) {
      case SSL_CTRL_SET_MSG_CALLBACK:
          ctx->msg_callback = (void (*)
                               (int write_p, int version, int content_type,
                                const void *buf, size_t len, SSL *ssl,
                                void *arg))(fp);
          return 1;
  
      default:
          return (ctx->method->ssl_ctx_callback_ctrl(ctx, cmd, fp));
      }
  }
  
  int ssl_cipher_id_cmp(const SSL_CIPHER *a, const SSL_CIPHER *b)
  {
      long l;
  
      l = a->id - b->id;
      if (l == 0L)
          return (0);
      else
          return ((l > 0) ? 1 : -1);
  }
  
  int ssl_cipher_ptr_id_cmp(const SSL_CIPHER *const *ap,
                            const SSL_CIPHER *const *bp)
  {
      long l;
  
      l = (*ap)->id - (*bp)->id;
      if (l == 0L)
          return (0);
      else
          return ((l > 0) ? 1 : -1);
  }
  
  /** 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) {
          if (s->cipher_list != NULL) {
              return (s->cipher_list);
          } else if ((s->ctx != NULL) && (s->ctx->cipher_list != NULL)) {
              return (s->ctx->cipher_list);
          }
      }
      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) {
          if (s->cipher_list_by_id != NULL) {
              return (s->cipher_list_by_id);
          } else 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)
  {
      SSL_CIPHER *c;
      STACK_OF(SSL_CIPHER) *sk;
  
      if (s == NULL)
          return (NULL);
      sk = SSL_get_ciphers(s);
      if ((sk == NULL) || (sk_SSL_CIPHER_num(sk) <= n))
          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, ctx->cert);
      /*
       * 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) {
          SSLerr(SSL_F_SSL_CTX_SET_CIPHER_LIST, 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, s->cert);
      /* see comment in SSL_CTX_set_cipher_list */
      if (sk == NULL)
          return 0;
      else if (sk_SSL_CIPHER_num(sk) == 0) {
          SSLerr(SSL_F_SSL_SET_CIPHER_LIST, SSL_R_NO_CIPHER_MATCH);
          return 0;
      }
      return 1;
  }
  
  /* works well for SSLv2, not so good for SSLv3 */
  char *SSL_get_shared_ciphers(const SSL *s, char *buf, int len)
  {
      char *p;
      STACK_OF(SSL_CIPHER) *sk;
      SSL_CIPHER *c;
      int i;
  
      if ((s->session == NULL) || (s->session->ciphers == NULL) || (len < 2))
          return (NULL);
  
      p = buf;
      sk = s->session->ciphers;
  
      if (sk_SSL_CIPHER_num(sk) == 0)
          return NULL;
  
      for (i = 0; i < sk_SSL_CIPHER_num(sk); i++) {
          int n;
  
          c = sk_SSL_CIPHER_value(sk, i);
          n = strlen(c->name);
          if (n + 1 > len) {
              if (p != buf)
                  --p;
              *p = '\0';
              return buf;
          }
          strcpy(p, c->name);
          p += n;
          *(p++) = ':';
          len -= n + 1;
      }
      p[-1] = '\0';
      return (buf);
  }
  
  int ssl_cipher_list_to_bytes(SSL *s, STACK_OF(SSL_CIPHER) *sk,
                               unsigned char *p,
                               int (*put_cb) (const SSL_CIPHER *,
                                              unsigned char *))
  {
      int i, j = 0;
      SSL_CIPHER *c;
      CERT *ct = s->cert;
      unsigned char *q;
      int empty_reneg_info_scsv = !s->renegotiate;
      /* Set disabled masks for this session */
      ssl_set_client_disabled(s);
  
      if (sk == NULL)
          return (0);
      q = p;
      if (put_cb == NULL)
          put_cb = s->method->put_cipher_by_char;
  
      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;
  #ifdef OPENSSL_SSL_DEBUG_BROKEN_PROTOCOL
          if (c->id == SSL3_CK_SCSV) {
              if (!empty_reneg_info_scsv)
                  continue;
              else
                  empty_reneg_info_scsv = 0;
          }
  #endif
          j = put_cb(c, p);
          p += j;
      }
      /*
       * If p == q, no ciphers; caller indicates an error. Otherwise, add
       * applicable SCSVs.
       */
      if (p != q) {
          if (empty_reneg_info_scsv) {
              static SSL_CIPHER scsv = {
                  0, NULL, SSL3_CK_SCSV, 0, 0, 0, 0, 0, 0, 0, 0, 0
              };
              j = put_cb(&scsv, p);
              p += j;
  #ifdef OPENSSL_RI_DEBUG
              fprintf(stderr,
                      "TLS_EMPTY_RENEGOTIATION_INFO_SCSV sent by client\n");
  #endif
          }
          if (s->mode & SSL_MODE_SEND_FALLBACK_SCSV) {
              static SSL_CIPHER scsv = {
                  0, NULL, SSL3_CK_FALLBACK_SCSV, 0, 0, 0, 0, 0, 0, 0, 0, 0
              };
              j = put_cb(&scsv, p);
              p += j;
          }
      }
  
      return (p - q);
  }
  
  STACK_OF(SSL_CIPHER) *ssl_bytes_to_cipher_list(SSL *s, unsigned char *p,
                                                 int num,
                                                 STACK_OF(SSL_CIPHER) **skp)
  {
      const SSL_CIPHER *c;
      STACK_OF(SSL_CIPHER) *sk;
      int i, n;
  
      if (s->s3)
          s->s3->send_connection_binding = 0;
  
      n = ssl_put_cipher_by_char(s, NULL, NULL);
      if (n == 0 || (num % n) != 0) {
          SSLerr(SSL_F_SSL_BYTES_TO_CIPHER_LIST,
                 SSL_R_ERROR_IN_RECEIVED_CIPHER_LIST);
          return (NULL);
      }
      if ((skp == NULL) || (*skp == NULL)) {
          sk = sk_SSL_CIPHER_new_null(); /* change perhaps later */
          if(sk == NULL) {
              SSLerr(SSL_F_SSL_BYTES_TO_CIPHER_LIST, ERR_R_MALLOC_FAILURE);
              return NULL;
          }
      } else {
          sk = *skp;
          sk_SSL_CIPHER_zero(sk);
      }
  
      if (s->cert->ciphers_raw)
          OPENSSL_free(s->cert->ciphers_raw);
      s->cert->ciphers_raw = BUF_memdup(p, num);
      if (s->cert->ciphers_raw == NULL) {
          SSLerr(SSL_F_SSL_BYTES_TO_CIPHER_LIST, ERR_R_MALLOC_FAILURE);
          goto err;
      }
      s->cert->ciphers_rawlen = (size_t)num;
  
      for (i = 0; i < num; i += n) {
          /* Check for TLS_EMPTY_RENEGOTIATION_INFO_SCSV */
          if (s->s3 && (n != 3 || !p[0]) &&
              (p[n - 2] == ((SSL3_CK_SCSV >> 8) & 0xff)) &&
              (p[n - 1] == (SSL3_CK_SCSV & 0xff))) {
              /* SCSV fatal if renegotiating */
              if (s->renegotiate) {
                  SSLerr(SSL_F_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;
              p += n;
  #ifdef OPENSSL_RI_DEBUG
              fprintf(stderr, "SCSV received by server\n");
  #endif
              continue;
          }
  
          /* Check for TLS_FALLBACK_SCSV */
          if ((n != 3 || !p[0]) &&
              (p[n - 2] == ((SSL3_CK_FALLBACK_SCSV >> 8) & 0xff)) &&
              (p[n - 1] == (SSL3_CK_FALLBACK_SCSV & 0xff))) {
              /*
               * The SCSV indicates that the client previously tried a higher
               * version. Fail if the current version is an unexpected
               * downgrade.
               */
              if (!SSL_ctrl(s, SSL_CTRL_CHECK_PROTO_VERSION, 0, NULL)) {
                  SSLerr(SSL_F_SSL_BYTES_TO_CIPHER_LIST,
                         SSL_R_INAPPROPRIATE_FALLBACK);
                  if (s->s3)
                      ssl3_send_alert(s, SSL3_AL_FATAL,
                                      SSL_AD_INAPPROPRIATE_FALLBACK);
                  goto err;
              }
              p += n;
              continue;
          }
  
          c = ssl_get_cipher_by_char(s, p);
          p += n;
          if (c != NULL) {
              if (!sk_SSL_CIPHER_push(sk, c)) {
                  SSLerr(SSL_F_SSL_BYTES_TO_CIPHER_LIST, ERR_R_MALLOC_FAILURE);
                  goto err;
              }
          }
      }
  
      if (skp != NULL)
          *skp = sk;
      return (sk);
   err:
      if ((skp == NULL) || (*skp == NULL))
          sk_SSL_CIPHER_free(sk);
      return (NULL);
  }
  
  #ifndef OPENSSL_NO_TLSEXT
  /** 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;
  }
  
  /*
   * 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(unsigned char **out, unsigned char *outlen,
                            const unsigned char *server,
                            unsigned int server_len,
                            const unsigned char *client,
                            unsigned int client_len)
  {
      unsigned int i, j;
      const unsigned char *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 = (unsigned char *)result + 1;
      *outlen = result[0];
      return status;
  }
  
  # ifndef OPENSSL_NO_NEXTPROTONEG
  /*
   * 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 unsigned char **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 unsigned char
                                                        **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, unsigned char **out,
                                                   unsigned char *outlen,
                                                   const unsigned char *in,
                                                   unsigned int inlen,
                                                   void *arg), void *arg)
  {
      ctx->next_proto_select_cb = cb;
      ctx->next_proto_select_cb_arg = arg;
  }
  # endif
  
  /*
   * SSL_CTX_set_alpn_protos sets the ALPN protocol list on |ctx| to |protos|.
   * |protos| must be in wire-format (i.e. a series of non-empty, 8-bit
   * length-prefixed strings). Returns 0 on success.
   */
  int SSL_CTX_set_alpn_protos(SSL_CTX *ctx, const unsigned char *protos,
                              unsigned protos_len)
  {
      if (ctx->alpn_client_proto_list)
          OPENSSL_free(ctx->alpn_client_proto_list);
  
      ctx->alpn_client_proto_list = OPENSSL_malloc(protos_len);
      if (!ctx->alpn_client_proto_list)
          return 1;
      memcpy(ctx->alpn_client_proto_list, protos, protos_len);
      ctx->alpn_client_proto_list_len = protos_len;
  
      return 0;
  }
  
  /*
   * SSL_set_alpn_protos sets the ALPN protocol list on |ssl| to |protos|.
   * |protos| must be in wire-format (i.e. a series of non-empty, 8-bit
   * length-prefixed strings). Returns 0 on success.
   */
  int SSL_set_alpn_protos(SSL *ssl, const unsigned char *protos,
                          unsigned protos_len)
  {
      if (ssl->alpn_client_proto_list)
          OPENSSL_free(ssl->alpn_client_proto_list);
  
      ssl->alpn_client_proto_list = OPENSSL_malloc(protos_len);
      if (!ssl->alpn_client_proto_list)
          return 1;
      memcpy(ssl->alpn_client_proto_list, protos, protos_len);
      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 unsigned char **out,
                                             unsigned char *outlen,
                                             const unsigned char *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 unsigned char **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;
  }
  
  #endif                          /* !OPENSSL_NO_TLSEXT */
  
  int SSL_export_keying_material(SSL *s, unsigned char *out, size_t olen,
                                 const char *label, size_t llen,
                                 const unsigned char *context, size_t contextlen,
                                 int use_context)
  {
      if (s->version < TLS1_VERSION && s->version != DTLS1_BAD_VER)
          return -1;
  
      return s->method->ssl3_enc->export_keying_material(s, out, olen, label,
                                                         llen, context,
                                                         contextlen, use_context);
  }
  
  static unsigned long ssl_session_hash(const SSL_SESSION *a)
  {
      const unsigned char *session_id = a->session_id;
      unsigned long l;
      unsigned char tmp_storage[4];
  
      if (a->session_id_length < sizeof(tmp_storage)) {
          memset(tmp_storage, 0, sizeof(tmp_storage));
          memcpy(tmp_storage, a->session_id, a->session_id_length);
          session_id = tmp_storage;
      }
  
      l = (unsigned long)
          ((unsigned long)session_id[0]) |
          ((unsigned long)session_id[1] << 8L) |
          ((unsigned long)session_id[2] << 16L) |
          ((unsigned long)session_id[3] << 24L);
      return (l);
  }
  
  /*
   * 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));
  }
  
  /*
   * These wrapper functions should remain rather than redeclaring
   * SSL_SESSION_hash and SSL_SESSION_cmp for void* types and casting each
   * variable. The reason is that the functions aren't static, they're exposed
   * via ssl.h.
   */
  static IMPLEMENT_LHASH_HASH_FN(ssl_session, SSL_SESSION)
  static IMPLEMENT_LHASH_COMP_FN(ssl_session, SSL_SESSION)
  
  SSL_CTX *SSL_CTX_new(const SSL_METHOD *meth)
  {
      SSL_CTX *ret = NULL;
  
      if (meth == NULL) {
          SSLerr(SSL_F_SSL_CTX_NEW, SSL_R_NULL_SSL_METHOD_PASSED);
          return (NULL);
      }
  #ifdef OPENSSL_FIPS
      if (FIPS_mode() && (meth->version < TLS1_VERSION)) {
          SSLerr(SSL_F_SSL_CTX_NEW, SSL_R_ONLY_TLS_ALLOWED_IN_FIPS_MODE);
          return NULL;
      }
  #endif
  
      if (SSL_get_ex_data_X509_STORE_CTX_idx() < 0) {
          SSLerr(SSL_F_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 = meth;
  
      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 = meth->get_timeout();
  
      ret->new_session_cb = 0;
      ret->remove_session_cb = 0;
      ret->get_session_cb = 0;
      ret->generate_session_id = 0;
  
      memset((char *)&ret->stats, 0, sizeof(ret->stats));
  
      ret->references = 1;
      ret->quiet_shutdown = 0;
  
  /*  ret->cipher=NULL;*/
  /*-
      ret->s2->challenge=NULL;
      ret->master_key=NULL;
      ret->key_arg=NULL;
      ret->s2->conn_id=NULL; */
  
      ret->info_callback = NULL;
  
      ret->app_verify_callback = 0;
      ret->app_verify_arg = NULL;
  
      ret->max_cert_list = SSL_MAX_CERT_LIST_DEFAULT;
      ret->read_ahead = 0;
      ret->msg_callback = 0;
      ret->msg_callback_arg = NULL;
      ret->verify_mode = SSL_VERIFY_NONE;
  #if 0
      ret->verify_depth = -1;     /* Don't impose a limit (but x509_lu.c does) */
  #endif
      ret->sid_ctx_length = 0;
      ret->default_verify_callback = NULL;
      if ((ret->cert = ssl_cert_new()) == NULL)
          goto err;
  
      ret->default_passwd_callback = 0;
      ret->default_passwd_callback_userdata = NULL;
      ret->client_cert_cb = 0;
      ret->app_gen_cookie_cb = 0;
      ret->app_verify_cookie_cb = 0;
  
      ret->sessions = lh_SSL_SESSION_new();
      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,
                             meth->version ==
                             SSL2_VERSION ? "SSLv2" : SSL_DEFAULT_CIPHER_LIST,
                             ret->cert);
      if (ret->cipher_list == NULL || sk_SSL_CIPHER_num(ret->cipher_list) <= 0) {
          SSLerr(SSL_F_SSL_CTX_NEW, SSL_R_LIBRARY_HAS_NO_CIPHERS);
          goto err2;
      }
  
      ret->param = X509_VERIFY_PARAM_new();
      if (!ret->param)
          goto err;
  
      if ((ret->rsa_md5 = EVP_get_digestbyname("ssl2-md5")) == NULL) {
          SSLerr(SSL_F_SSL_CTX_NEW, SSL_R_UNABLE_TO_LOAD_SSL2_MD5_ROUTINES);
          goto err2;
      }
      if ((ret->md5 = EVP_get_digestbyname("ssl3-md5")) == NULL) {
          SSLerr(SSL_F_SSL_CTX_NEW, SSL_R_UNABLE_TO_LOAD_SSL3_MD5_ROUTINES);
          goto err2;
      }
      if ((ret->sha1 = EVP_get_digestbyname("ssl3-sha1")) == NULL) {
          SSLerr(SSL_F_SSL_CTX_NEW, SSL_R_UNABLE_TO_LOAD_SSL3_SHA1_ROUTINES);
          goto err2;
      }
  
      if ((ret->client_CA = sk_X509_NAME_new_null()) == NULL)
          goto err;
  
      CRYPTO_new_ex_data(CRYPTO_EX_INDEX_SSL_CTX, ret, &ret->ex_data);
  
      ret->extra_certs = NULL;
      /* No compression for DTLS */
      if (!(meth->ssl3_enc->enc_flags & SSL_ENC_FLAG_DTLS))
          ret->comp_methods = SSL_COMP_get_compression_methods();
  
      ret->max_send_fragment = SSL3_RT_MAX_PLAIN_LENGTH;
  
  #ifndef OPENSSL_NO_TLSEXT
      ret->tlsext_servername_callback = 0;
      ret->tlsext_servername_arg = NULL;
      /* Setup RFC4507 ticket keys */
      if ((RAND_bytes(ret->tlsext_tick_key_name, 16) <= 0)
          || (RAND_bytes(ret->tlsext_tick_hmac_key, 16) <= 0)
          || (RAND_bytes(ret->tlsext_tick_aes_key, 16) <= 0))
          ret->options |= SSL_OP_NO_TICKET;
  
      ret->tlsext_status_cb = 0;
      ret->tlsext_status_arg = NULL;
  
  # ifndef OPENSSL_NO_NEXTPROTONEG
      ret->next_protos_advertised_cb = 0;
      ret->next_proto_select_cb = 0;
  # endif
  #endif
  #ifndef OPENSSL_NO_PSK
      ret->psk_identity_hint = NULL;
      ret->psk_client_callback = NULL;
      ret->psk_server_callback = NULL;
  #endif
  #ifndef OPENSSL_NO_SRP
      SSL_CTX_SRP_CTX_init(ret);
  #endif
  #ifndef OPENSSL_NO_BUF_FREELISTS
      ret->freelist_max_len = SSL_MAX_BUF_FREELIST_LEN_DEFAULT;
      ret->rbuf_freelist = OPENSSL_malloc(sizeof(SSL3_BUF_FREELIST));
      if (!ret->rbuf_freelist)
          goto err;
      ret->rbuf_freelist->chunklen = 0;
      ret->rbuf_freelist->len = 0;
      ret->rbuf_freelist->head = NULL;
      ret->wbuf_freelist = OPENSSL_malloc(sizeof(SSL3_BUF_FREELIST));
      if (!ret->wbuf_freelist)
          goto err;
      ret->wbuf_freelist->chunklen = 0;
      ret->wbuf_freelist->len = 0;
      ret->wbuf_freelist->head = NULL;
  #endif
  #ifndef OPENSSL_NO_ENGINE
      ret->client_cert_engine = NULL;
  # ifdef OPENSSL_SSL_CLIENT_ENGINE_AUTO
  #  define eng_strx(x)     #x
  #  define eng_str(x)      eng_strx(x)
      /* Use specific client engine automatically... ignore errors */
      {
          ENGINE *eng;
          eng = ENGINE_by_id(eng_str(OPENSSL_SSL_CLIENT_ENGINE_AUTO));
          if (!eng) {
              ERR_clear_error();
              ENGINE_load_builtin_engines();
              eng = ENGINE_by_id(eng_str(OPENSSL_SSL_CLIENT_ENGINE_AUTO));
          }
          if (!eng || !SSL_CTX_set_client_cert_engine(ret, eng))
              ERR_clear_error();
      }
  # endif
  #endif
      /*
       * Default is to connect to non-RI servers. When RI is more widely
       * deployed might change this.
       */
      ret->options |= SSL_OP_LEGACY_SERVER_CONNECT;
  
      /*
       * Disable SSLv2 by default, callers that want to enable SSLv2 will have to
       * explicitly clear this option via either of SSL_CTX_clear_options() or
       * SSL_clear_options().
       */
      ret->options |= SSL_OP_NO_SSLv2;
  
      return (ret);
   err:
      SSLerr(SSL_F_SSL_CTX_NEW, ERR_R_MALLOC_FAILURE);
   err2:
      if (ret != NULL)
          SSL_CTX_free(ret);
      return (NULL);
  }
  
  #if 0
  static void SSL_COMP_free(SSL_COMP *comp)
  {
      OPENSSL_free(comp);
  }
  #endif
  
  #ifndef OPENSSL_NO_BUF_FREELISTS
  static void ssl_buf_freelist_free(SSL3_BUF_FREELIST *list)
  {
      SSL3_BUF_FREELIST_ENTRY *ent, *next;
      for (ent = list->head; ent; ent = next) {
          next = ent->next;
          OPENSSL_free(ent);
      }
      OPENSSL_free(list);
  }
  #endif
  
  void SSL_CTX_free(SSL_CTX *a)
  {
      int i;
  
      if (a == NULL)
          return;
  
      i = CRYPTO_add(&a->references, -1, CRYPTO_LOCK_SSL_CTX);
  #ifdef REF_PRINT
      REF_PRINT("SSL_CTX", a);
  #endif
      if (i > 0)
          return;
  #ifdef REF_CHECK
      if (i < 0) {
          fprintf(stderr, "SSL_CTX_free, bad reference count\n");
          abort();                /* ok */
      }
  #endif
  
      if (a->param)
          X509_VERIFY_PARAM_free(a->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].)
       */
      if (a->sessions != NULL)
          SSL_CTX_flush_sessions(a, 0);
  
      CRYPTO_free_ex_data(CRYPTO_EX_INDEX_SSL_CTX, a, &a->ex_data);
  
      if (a->sessions != NULL)
          lh_SSL_SESSION_free(a->sessions);
  
      if (a->cert_store != NULL)
          X509_STORE_free(a->cert_store);
      if (a->cipher_list != NULL)
          sk_SSL_CIPHER_free(a->cipher_list);
      if (a->cipher_list_by_id != NULL)
          sk_SSL_CIPHER_free(a->cipher_list_by_id);
      if (a->cert != NULL)
          ssl_cert_free(a->cert);
      if (a->client_CA != NULL)
          sk_X509_NAME_pop_free(a->client_CA, X509_NAME_free);
      if (a->extra_certs != NULL)
          sk_X509_pop_free(a->extra_certs, X509_free);
  #if 0                           /* This should never be done, since it
                                   * removes a global database */
      if (a->comp_methods != NULL)
          sk_SSL_COMP_pop_free(a->comp_methods, SSL_COMP_free);
  #else
      a->comp_methods = NULL;
  #endif
  
  #ifndef OPENSSL_NO_SRTP
      if (a->srtp_profiles)
          sk_SRTP_PROTECTION_PROFILE_free(a->srtp_profiles);
  #endif
  
  #ifndef OPENSSL_NO_PSK
      if (a->psk_identity_hint)
          OPENSSL_free(a->psk_identity_hint);
  #endif
  #ifndef OPENSSL_NO_SRP
      SSL_CTX_SRP_CTX_free(a);
  #endif
  #ifndef OPENSSL_NO_ENGINE
      if (a->client_cert_engine)
          ENGINE_finish(a->client_cert_engine);
  #endif
  
  #ifndef OPENSSL_NO_BUF_FREELISTS
      if (a->wbuf_freelist)
          ssl_buf_freelist_free(a->wbuf_freelist);
      if (a->rbuf_freelist)
          ssl_buf_freelist_free(a->rbuf_freelist);
  #endif
  #ifndef OPENSSL_NO_TLSEXT
  # ifndef OPENSSL_NO_EC
      if (a->tlsext_ecpointformatlist)
          OPENSSL_free(a->tlsext_ecpointformatlist);
      if (a->tlsext_ellipticcurvelist)
          OPENSSL_free(a->tlsext_ellipticcurvelist);
  # endif                         /* OPENSSL_NO_EC */
      if (a->alpn_client_proto_list != NULL)
          OPENSSL_free(a->alpn_client_proto_list);
  #endif
  
      OPENSSL_free(a);
  }
  
  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);
  }
  
  void ssl_set_cert_masks(CERT *c, const SSL_CIPHER *cipher)
  {
      CERT_PKEY *cpk;
      int rsa_enc, rsa_tmp, rsa_sign, dh_tmp, dh_rsa, dh_dsa, dsa_sign;
      int rsa_enc_export, dh_rsa_export, dh_dsa_export;
      int rsa_tmp_export, dh_tmp_export, kl;
      unsigned long mask_k, mask_a, emask_k, emask_a;
  #ifndef OPENSSL_NO_ECDSA
      int have_ecc_cert, ecdsa_ok, ecc_pkey_size;
  #endif
  #ifndef OPENSSL_NO_ECDH
      int have_ecdh_tmp, ecdh_ok;
  #endif
  #ifndef OPENSSL_NO_EC
      X509 *x = NULL;
      EVP_PKEY *ecc_pkey = NULL;
      int signature_nid = 0, pk_nid = 0, md_nid = 0;
  #endif
      if (c == NULL)
          return;
  
      kl = SSL_C_EXPORT_PKEYLENGTH(cipher);
  
  #ifndef OPENSSL_NO_RSA
      rsa_tmp = (c->rsa_tmp != NULL || c->rsa_tmp_cb != NULL);
      rsa_tmp_export = (c->rsa_tmp_cb != NULL ||
                        (rsa_tmp && RSA_size(c->rsa_tmp) * 8 <= kl));
  #else
      rsa_tmp = rsa_tmp_export = 0;
  #endif
  #ifndef OPENSSL_NO_DH
      dh_tmp = (c->dh_tmp != NULL || c->dh_tmp_cb != NULL);
      dh_tmp_export = (c->dh_tmp_cb != NULL ||
                       (dh_tmp && DH_size(c->dh_tmp) * 8 <= kl));
  #else
      dh_tmp = dh_tmp_export = 0;
  #endif
  
  #ifndef OPENSSL_NO_ECDH
      have_ecdh_tmp = (c->ecdh_tmp || c->ecdh_tmp_cb || c->ecdh_tmp_auto);
  #endif
      cpk = &(c->pkeys[SSL_PKEY_RSA_ENC]);
      rsa_enc = cpk->valid_flags & CERT_PKEY_VALID;
      rsa_enc_export = (rsa_enc && EVP_PKEY_size(cpk->privatekey) * 8 <= kl);
      cpk = &(c->pkeys[SSL_PKEY_RSA_SIGN]);
      rsa_sign = cpk->valid_flags & CERT_PKEY_SIGN;
      cpk = &(c->pkeys[SSL_PKEY_DSA_SIGN]);
      dsa_sign = cpk->valid_flags & CERT_PKEY_SIGN;
      cpk = &(c->pkeys[SSL_PKEY_DH_RSA]);
      dh_rsa = cpk->valid_flags & CERT_PKEY_VALID;
      dh_rsa_export = (dh_rsa && EVP_PKEY_size(cpk->privatekey) * 8 <= kl);
      cpk = &(c->pkeys[SSL_PKEY_DH_DSA]);
  /* FIX THIS EAY EAY EAY */
      dh_dsa = cpk->valid_flags & CERT_PKEY_VALID;
      dh_dsa_export = (dh_dsa && EVP_PKEY_size(cpk->privatekey) * 8 <= kl);
      cpk = &(c->pkeys[SSL_PKEY_ECC]);
  #ifndef OPENSSL_NO_EC
      have_ecc_cert = cpk->valid_flags & CERT_PKEY_VALID;
  #endif
      mask_k = 0;
      mask_a = 0;
      emask_k = 0;
      emask_a = 0;
  
  #ifdef CIPHER_DEBUG
      fprintf(stderr,
              "rt=%d rte=%d dht=%d ecdht=%d re=%d ree=%d rs=%d ds=%d dhr=%d dhd=%d\n",
              rsa_tmp, rsa_tmp_export, dh_tmp, have_ecdh_tmp, rsa_enc,
              rsa_enc_export, rsa_sign, dsa_sign, dh_rsa, dh_dsa);
  #endif
  
      cpk = &(c->pkeys[SSL_PKEY_GOST01]);
      if (cpk->x509 != NULL && cpk->privatekey != NULL) {
          mask_k |= SSL_kGOST;
          mask_a |= SSL_aGOST01;
      }
      cpk = &(c->pkeys[SSL_PKEY_GOST94]);
      if (cpk->x509 != NULL && cpk->privatekey != NULL) {
          mask_k |= SSL_kGOST;
          mask_a |= SSL_aGOST94;
      }
  
      if (rsa_enc || (rsa_tmp && rsa_sign))
          mask_k |= SSL_kRSA;
      if (rsa_enc_export || (rsa_tmp_export && (rsa_sign || rsa_enc)))
          emask_k |= SSL_kRSA;
  
  #if 0
      /* The match needs to be both kEDH and aRSA or aDSA, so don't worry */
      if ((dh_tmp || dh_rsa || dh_dsa) && (rsa_enc || rsa_sign || dsa_sign))
          mask_k |= SSL_kEDH;
      if ((dh_tmp_export || dh_rsa_export || dh_dsa_export) &&
          (rsa_enc || rsa_sign || dsa_sign))
          emask_k |= SSL_kEDH;
  #endif
  
      if (dh_tmp_export)
          emask_k |= SSL_kEDH;
  
      if (dh_tmp)
          mask_k |= SSL_kEDH;
  
      if (dh_rsa)
          mask_k |= SSL_kDHr;
      if (dh_rsa_export)
          emask_k |= SSL_kDHr;
  
      if (dh_dsa)
          mask_k |= SSL_kDHd;
      if (dh_dsa_export)
          emask_k |= SSL_kDHd;
  
      if (mask_k & (SSL_kDHr | SSL_kDHd))
          mask_a |= SSL_aDH;
  
      if (rsa_enc || rsa_sign) {
          mask_a |= SSL_aRSA;
          emask_a |= SSL_aRSA;
      }
  
      if (dsa_sign) {
          mask_a |= SSL_aDSS;
          emask_a |= SSL_aDSS;
      }
  
      mask_a |= SSL_aNULL;
      emask_a |= SSL_aNULL;
  
  #ifndef OPENSSL_NO_KRB5
      mask_k |= SSL_kKRB5;
      mask_a |= SSL_aKRB5;
      emask_k |= SSL_kKRB5;
      emask_a |= SSL_aKRB5;
  #endif
  
      /*
       * An ECC certificate may be usable for ECDH and/or ECDSA cipher suites
       * depending on the key usage extension.
       */
  #ifndef OPENSSL_NO_EC
      if (have_ecc_cert) {
          cpk = &c->pkeys[SSL_PKEY_ECC];
          x = cpk->x509;
          /* This call populates extension flags (ex_flags) */
          X509_check_purpose(x, -1, 0);
  # ifndef OPENSSL_NO_ECDH
          ecdh_ok = (x->ex_flags & EXFLAG_KUSAGE) ?
              (x->ex_kusage & X509v3_KU_KEY_AGREEMENT) : 1;
  # endif
          ecdsa_ok = (x->ex_flags & EXFLAG_KUSAGE) ?
              (x->ex_kusage & X509v3_KU_DIGITAL_SIGNATURE) : 1;
          if (!(cpk->valid_flags & CERT_PKEY_SIGN))
              ecdsa_ok = 0;
          ecc_pkey = X509_get_pubkey(x);
          ecc_pkey_size = (ecc_pkey != NULL) ? EVP_PKEY_bits(ecc_pkey) : 0;
          EVP_PKEY_free(ecc_pkey);
          if ((x->sig_alg) && (x->sig_alg->algorithm)) {
              signature_nid = OBJ_obj2nid(x->sig_alg->algorithm);
              OBJ_find_sigid_algs(signature_nid, &md_nid, &pk_nid);
          }
  # ifndef OPENSSL_NO_ECDH
          if (ecdh_ok) {
  
              if (pk_nid == NID_rsaEncryption || pk_nid == NID_rsa) {
                  mask_k |= SSL_kECDHr;
                  mask_a |= SSL_aECDH;
                  if (ecc_pkey_size <= 163) {
                      emask_k |= SSL_kECDHr;
                      emask_a |= SSL_aECDH;
                  }
              }
  
              if (pk_nid == NID_X9_62_id_ecPublicKey) {
                  mask_k |= SSL_kECDHe;
                  mask_a |= SSL_aECDH;
                  if (ecc_pkey_size <= 163) {
                      emask_k |= SSL_kECDHe;
                      emask_a |= SSL_aECDH;
                  }
              }
          }
  # endif
  # ifndef OPENSSL_NO_ECDSA
          if (ecdsa_ok) {
              mask_a |= SSL_aECDSA;
              emask_a |= SSL_aECDSA;
          }
  # endif
      }
  #endif
  
  #ifndef OPENSSL_NO_ECDH
      if (have_ecdh_tmp) {
          mask_k |= SSL_kEECDH;
          emask_k |= SSL_kEECDH;
      }
  #endif
  
  #ifndef OPENSSL_NO_PSK
      mask_k |= SSL_kPSK;
      mask_a |= SSL_aPSK;
      emask_k |= SSL_kPSK;
      emask_a |= SSL_aPSK;
  #endif
  
      c->mask_k = mask_k;
      c->mask_a = mask_a;
      c->export_mask_k = emask_k;
      c->export_mask_a = emask_a;
      c->valid = 1;
  }
  
  /* This handy macro borrowed from crypto/x509v3/v3_purp.c */
  #define ku_reject(x, usage) \
          (((x)->ex_flags & EXFLAG_KUSAGE) && !((x)->ex_kusage & (usage)))
  
  #ifndef OPENSSL_NO_EC
  
  int ssl_check_srvr_ecc_cert_and_alg(X509 *x, SSL *s)
  {
      unsigned long alg_k, alg_a;
      EVP_PKEY *pkey = NULL;
      int keysize = 0;
      int signature_nid = 0, md_nid = 0, pk_nid = 0;
      const SSL_CIPHER *cs = s->s3->tmp.new_cipher;
  
      alg_k = cs->algorithm_mkey;
      alg_a = cs->algorithm_auth;
  
      if (SSL_C_IS_EXPORT(cs)) {
          /* ECDH key length in export ciphers must be <= 163 bits */
          pkey = X509_get_pubkey(x);
          if (pkey == NULL)
              return 0;
          keysize = EVP_PKEY_bits(pkey);
          EVP_PKEY_free(pkey);
          if (keysize > 163)
              return 0;
      }
  
      /* This call populates the ex_flags field correctly */
      X509_check_purpose(x, -1, 0);
      if ((x->sig_alg) && (x->sig_alg->algorithm)) {
          signature_nid = OBJ_obj2nid(x->sig_alg->algorithm);
          OBJ_find_sigid_algs(signature_nid, &md_nid, &pk_nid);
      }
      if (alg_k & SSL_kECDHe || alg_k & SSL_kECDHr) {
          /* key usage, if present, must allow key agreement */
          if (ku_reject(x, X509v3_KU_KEY_AGREEMENT)) {
              SSLerr(SSL_F_SSL_CHECK_SRVR_ECC_CERT_AND_ALG,
                     SSL_R_ECC_CERT_NOT_FOR_KEY_AGREEMENT);
              return 0;
          }
          if ((alg_k & SSL_kECDHe) && TLS1_get_version(s) < TLS1_2_VERSION) {
              /* signature alg must be ECDSA */
              if (pk_nid != NID_X9_62_id_ecPublicKey) {
                  SSLerr(SSL_F_SSL_CHECK_SRVR_ECC_CERT_AND_ALG,
                         SSL_R_ECC_CERT_SHOULD_HAVE_SHA1_SIGNATURE);
                  return 0;
              }
          }
          if ((alg_k & SSL_kECDHr) && TLS1_get_version(s) < TLS1_2_VERSION) {
              /* signature alg must be RSA */
  
              if (pk_nid != NID_rsaEncryption && pk_nid != NID_rsa) {
                  SSLerr(SSL_F_SSL_CHECK_SRVR_ECC_CERT_AND_ALG,
                         SSL_R_ECC_CERT_SHOULD_HAVE_RSA_SIGNATURE);
                  return 0;
              }
          }
      }
      if (alg_a & SSL_aECDSA) {
          /* key usage, if present, must allow signing */
          if (ku_reject(x, X509v3_KU_DIGITAL_SIGNATURE)) {
              SSLerr(SSL_F_SSL_CHECK_SRVR_ECC_CERT_AND_ALG,
                     SSL_R_ECC_CERT_NOT_FOR_SIGNING);
              return 0;
          }
      }
  
      return 1;                   /* all checks are ok */
  }
  
  #endif
  
  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)
          SSLerr(SSL_F_SSL_GET_SERVER_CERT_INDEX, ERR_R_INTERNAL_ERROR);
      return idx;
  }
  
  CERT_PKEY *ssl_get_server_send_pkey(const SSL *s)
  {
      CERT *c;
      int i;
  
      c = s->cert;
      if (!s->s3 || !s->s3->tmp.new_cipher)
          return NULL;
      ssl_set_cert_masks(c, s->s3->tmp.new_cipher);
  
  #ifdef OPENSSL_SSL_DEBUG_BROKEN_PROTOCOL
      /*
       * Broken protocol test: return last used certificate: which may mismatch
       * the one expected.
       */
      if (c->cert_flags & SSL_CERT_FLAG_BROKEN_PROTOCOL)
          return c->key;
  #endif
  
      i = ssl_get_server_cert_index(s);
  
      /* This may or may not be an error. */
      if (i < 0)
          return NULL;
  
      /* May be NULL. */
      return &c->pkeys[i];
  }
  
  EVP_PKEY *ssl_get_sign_pkey(SSL *s, const SSL_CIPHER *cipher,
                              const EVP_MD **pmd)
  {
      unsigned long alg_a;
      CERT *c;
      int idx = -1;
  
      alg_a = cipher->algorithm_auth;
      c = s->cert;
  
  #ifdef OPENSSL_SSL_DEBUG_BROKEN_PROTOCOL
      /*
       * Broken protocol test: use last key: which may mismatch the one
       * expected.
       */
      if (c->cert_flags & SSL_CERT_FLAG_BROKEN_PROTOCOL)
          idx = c->key - c->pkeys;
      else
  #endif
  
      if ((alg_a & SSL_aDSS) &&
              (c->pkeys[SSL_PKEY_DSA_SIGN].privatekey != NULL))
          idx = SSL_PKEY_DSA_SIGN;
      else 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) {
          SSLerr(SSL_F_SSL_GET_SIGN_PKEY, ERR_R_INTERNAL_ERROR);
          return (NULL);
      }
      if (pmd)
          *pmd = c->pkeys[idx].digest;
      return c->pkeys[idx].privatekey;
  }
  
  #ifndef OPENSSL_NO_TLSEXT
  int ssl_get_server_cert_serverinfo(SSL *s, const unsigned char **serverinfo,
                                     size_t *serverinfo_length)
  {
      CERT *c = NULL;
      int i = 0;
      *serverinfo_length = 0;
  
      c = s->cert;
      i = ssl_get_server_cert_index(s);
  
      if (i == -1)
          return 0;
      if (c->pkeys[i].serverinfo == NULL)
          return 0;
  
      *serverinfo = c->pkeys[i].serverinfo;
      *serverinfo_length = c->pkeys[i].serverinfo_length;
      return 1;
  }
  #endif
  
  void ssl_update_cache(SSL *s, int mode)
  {
      int i;
  
      /*
       * If the session_id_length is 0, we are not supposed to cache it, and it
       * would be rather hard to do anyway :-)
       */
      if (s->session->session_id_length == 0)
          return;
  
      i = s->session_ctx->session_cache_mode;
      if ((i & mode) && (!s->hit)
          && ((i & SSL_SESS_CACHE_NO_INTERNAL_STORE)
              || SSL_CTX_add_session(s->session_ctx, s->session))
          && (s->session_ctx->new_session_cb != NULL)) {
          CRYPTO_add(&s->session->references, 1, CRYPTO_LOCK_SSL_SESSION);
          if (!s->session_ctx->new_session_cb(s, s->session))
              SSL_SESSION_free(s->session);
      }
  
      /* auto flush every 255 connections */
      if ((!(i & SSL_SESS_CACHE_NO_AUTO_CLEAR)) && ((i & mode) == mode)) {
          if ((((mode & SSL_SESS_CACHE_CLIENT)
                ? s->session_ctx->stats.sess_connect_good
                : s->session_ctx->stats.sess_accept_good) & 0xff) == 0xff) {
              SSL_CTX_flush_sessions(s->session_ctx, (unsigned long)time(NULL));
          }
      }
  }
  
  const SSL_METHOD *SSL_CTX_get_ssl_method(SSL_CTX *ctx)
  {
      return ctx->method;
  }
  
  const SSL_METHOD *SSL_get_ssl_method(SSL *s)
  {
      return (s->method);
  }
  
  int SSL_set_ssl_method(SSL *s, const SSL_METHOD *meth)
  {
      int conn = -1;
      int ret = 1;
  
      if (s->method != meth) {
          if (s->handshake_func != NULL)
              conn = (s->handshake_func == s->method->ssl_connect);
  
          if (s->method->version == meth->version)
              s->method = meth;
          else {
              s->method->ssl_free(s);
              s->method = meth;
              ret = s->method->ssl_new(s);
          }
  
          if (conn == 1)
              s->handshake_func = meth->ssl_connect;
          else if (conn == 0)
              s->handshake_func = meth->ssl_accept;
      }
      return (ret);
  }
  
  int SSL_get_error(const SSL *s, int i)
  {
      int reason;
      unsigned long l;
      BIO *bio;
  
      if (i > 0)
          return (SSL_ERROR_NONE);
  
      /*
       * Make things return SSL_ERROR_SYSCALL when doing SSL_do_handshake etc,
       * where we do encode the error
       */
      if ((l = ERR_peek_error()) != 0) {
          if (ERR_GET_LIB(l) == ERR_LIB_SYS)
              return (SSL_ERROR_SYSCALL);
          else
              return (SSL_ERROR_SSL);
      }
  
      if ((i < 0) && SSL_want_read(s)) {
          bio = SSL_get_rbio(s);
          if (BIO_should_read(bio))
              return (SSL_ERROR_WANT_READ);
          else 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);
          else if (BIO_should_io_special(bio)) {
              reason = BIO_get_retry_reason(bio);
              if (reason == BIO_RR_CONNECT)
                  return (SSL_ERROR_WANT_CONNECT);
              else if (reason == BIO_RR_ACCEPT)
                  return (SSL_ERROR_WANT_ACCEPT);
              else
                  return (SSL_ERROR_SYSCALL); /* unknown */
          }
      }
  
      if ((i < 0) && SSL_want_write(s)) {
          bio = SSL_get_wbio(s);
          if (BIO_should_write(bio))
              return (SSL_ERROR_WANT_WRITE);
          else if (BIO_should_read(bio))
              /*
               * See above (SSL_want_read(s) with BIO_should_write(bio))
               */
              return (SSL_ERROR_WANT_READ);
          else if (BIO_should_io_special(bio)) {
              reason = BIO_get_retry_reason(bio);
              if (reason == BIO_RR_CONNECT)
                  return (SSL_ERROR_WANT_CONNECT);
              else if (reason == BIO_RR_ACCEPT)
                  return (SSL_ERROR_WANT_ACCEPT);
              else
                  return (SSL_ERROR_SYSCALL);
          }
      }
      if ((i < 0) && SSL_want_x509_lookup(s)) {
          return (SSL_ERROR_WANT_X509_LOOKUP);
      }
  
      if (i == 0) {
          if (s->version == SSL2_VERSION) {
              /* assume it is the socket being closed */
              return (SSL_ERROR_ZERO_RETURN);
          } else {
              if ((s->shutdown & SSL_RECEIVED_SHUTDOWN) &&
                  (s->s3->warn_alert == SSL_AD_CLOSE_NOTIFY))
                  return (SSL_ERROR_ZERO_RETURN);
          }
      }
      return (SSL_ERROR_SYSCALL);
  }
  
  int SSL_do_handshake(SSL *s)
  {
      int ret = 1;
  
      if (s->handshake_func == NULL) {
          SSLerr(SSL_F_SSL_DO_HANDSHAKE, SSL_R_CONNECTION_TYPE_NOT_SET);
          return (-1);
      }
  
      s->method->ssl_renegotiate_check(s);
  
      if (SSL_in_init(s) || SSL_in_before(s)) {
          ret = s->handshake_func(s);
      }
      return (ret);
  }
  
  /*
   * For the next 2 functions, SSL_clear() sets shutdown and so one of these
   * calls will reset it
   */
  void SSL_set_accept_state(SSL *s)
  {
      s->server = 1;
      s->shutdown = 0;
      s->state = SSL_ST_ACCEPT | SSL_ST_BEFORE;
      s->handshake_func = s->method->ssl_accept;
      /* clear the current cipher */
      ssl_clear_cipher_ctx(s);
      ssl_clear_hash_ctx(&s->read_hash);
      ssl_clear_hash_ctx(&s->write_hash);
  }
  
  void SSL_set_connect_state(SSL *s)
  {
      s->server = 0;
      s->shutdown = 0;
      s->state = SSL_ST_CONNECT | SSL_ST_BEFORE;
      s->handshake_func = s->method->ssl_connect;
      /* clear the current cipher */
      ssl_clear_cipher_ctx(s);
      ssl_clear_hash_ctx(&s->read_hash);
      ssl_clear_hash_ctx(&s->write_hash);
  }
  
  int ssl_undefined_function(SSL *s)
  {
      SSLerr(SSL_F_SSL_UNDEFINED_FUNCTION, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
      return (0);
  }
  
  int ssl_undefined_void_function(void)
  {
      SSLerr(SSL_F_SSL_UNDEFINED_VOID_FUNCTION,
             ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
      return (0);
  }
  
  int ssl_undefined_const_function(const SSL *s)
  {
      SSLerr(SSL_F_SSL_UNDEFINED_CONST_FUNCTION,
             ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
      return (0);
  }
  
  SSL_METHOD *ssl_bad_method(int ver)
  {
      SSLerr(SSL_F_SSL_BAD_METHOD, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
      return (NULL);
  }
  
  const char *SSL_get_version(const SSL *s)
  {
      if (s->version == TLS1_2_VERSION)
          return ("TLSv1.2");
      else if (s->version == TLS1_1_VERSION)
          return ("TLSv1.1");
      else if (s->version == TLS1_VERSION)
          return ("TLSv1");
      else if (s->version == SSL3_VERSION)
          return ("SSLv3");
      else if (s->version == SSL2_VERSION)
          return ("SSLv2");
      else if (s->version == DTLS1_BAD_VER)
          return ("DTLSv0.9");
      else if (s->version == DTLS1_VERSION)
          return ("DTLSv1");
      else if (s->version == DTLS1_2_VERSION)
          return ("DTLSv1.2");
      else
          return ("unknown");
  }
  
  SSL *SSL_dup(SSL *s)
  {
      STACK_OF(X509_NAME) *sk;
      X509_NAME *xn;
      SSL *ret;
      int i;
  
      if ((ret = SSL_new(SSL_get_SSL_CTX(s))) == NULL)
          return (NULL);
  
      ret->version = s->version;
      ret->type = s->type;
      ret->method = s->method;
  
      if (s->session != NULL) {
          /* This copies session-id, SSL_METHOD, sid_ctx, and 'cert' */
          SSL_copy_session_id(ret, s);
      } else {
          /*
           * No session has been established yet, so we have to expect that
           * s->cert or ret->cert will be changed later -- they should not both
           * point to the same object, and thus we can't use
           * SSL_copy_session_id.
           */
  
          ret->method->ssl_free(ret);
          ret->method = s->method;
          ret->method->ssl_new(ret);
  
          if (s->cert != NULL) {
              if (ret->cert != NULL) {
                  ssl_cert_free(ret->cert);
              }
              ret->cert = ssl_cert_dup(s->cert);
              if (ret->cert == NULL)
                  goto err;
          }
  
          SSL_set_session_id_context(ret, s->sid_ctx, s->sid_ctx_length);
      }
  
      ret->options = s->options;
      ret->mode = s->mode;
      SSL_set_max_cert_list(ret, SSL_get_max_cert_list(s));
      SSL_set_read_ahead(ret, SSL_get_read_ahead(s));
      ret->msg_callback = s->msg_callback;
      ret->msg_callback_arg = s->msg_callback_arg;
      SSL_set_verify(ret, SSL_get_verify_mode(s), SSL_get_verify_callback(s));
      SSL_set_verify_depth(ret, SSL_get_verify_depth(s));
      ret->generate_session_id = s->generate_session_id;
  
      SSL_set_info_callback(ret, SSL_get_info_callback(s));
  
      ret->debug = s->debug;
  
      /* copy app data, a little dangerous perhaps */
      if (!CRYPTO_dup_ex_data(CRYPTO_EX_INDEX_SSL, &ret->ex_data, &s->ex_data))
          goto err;
  
      /* setup rbio, and wbio */
      if (s->rbio != NULL) {
          if (!BIO_dup_state(s->rbio, (char *)&ret->rbio))
              goto err;
      }
      if (s->wbio != NULL) {
          if (s->wbio != s->rbio) {
              if (!BIO_dup_state(s->wbio, (char *)&ret->wbio))
                  goto err;
          } else
              ret->wbio = ret->rbio;
      }
      ret->rwstate = s->rwstate;
      ret->in_handshake = s->in_handshake;
      ret->handshake_func = s->handshake_func;
      ret->server = s->server;
      ret->renegotiate = s->renegotiate;
      ret->new_session = s->new_session;
      ret->quiet_shutdown = s->quiet_shutdown;
      ret->shutdown = s->shutdown;
      ret->state = s->state;      /* SSL_dup does not really work at any state,
                                   * though */
      ret->rstate = s->rstate;
      ret->init_num = 0;          /* would have to copy ret->init_buf,
                                   * ret->init_msg, ret->init_num,
                                   * ret->init_off */
      ret->hit = s->hit;
  
      X509_VERIFY_PARAM_inherit(ret->param, s->param);
  
      /* dup the cipher_list and cipher_list_by_id stacks */
      if (s->cipher_list != NULL) {
          if ((ret->cipher_list = sk_SSL_CIPHER_dup(s->cipher_list)) == NULL)
              goto err;
      }
      if (s->cipher_list_by_id != NULL)
          if ((ret->cipher_list_by_id = sk_SSL_CIPHER_dup(s->cipher_list_by_id))
              == NULL)
              goto err;
  
      /* Dup the client_CA list */
      if (s->client_CA != NULL) {
          if ((sk = sk_X509_NAME_dup(s->client_CA)) == NULL)
              goto err;
          ret->client_CA = sk;
          for (i = 0; i < sk_X509_NAME_num(sk); i++) {
              xn = sk_X509_NAME_value(sk, i);
              if (sk_X509_NAME_set(sk, i, X509_NAME_dup(xn)) == NULL) {
                  X509_NAME_free(xn);
                  goto err;
              }
          }
      }
  
      if (0) {
   err:
          if (ret != NULL)
              SSL_free(ret);
          ret = NULL;
      }
      return (ret);
  }
  
  void ssl_clear_cipher_ctx(SSL *s)
  {
      if (s->enc_read_ctx != NULL) {
          EVP_CIPHER_CTX_cleanup(s->enc_read_ctx);
          OPENSSL_free(s->enc_read_ctx);
          s->enc_read_ctx = NULL;
      }
      if (s->enc_write_ctx != NULL) {
          EVP_CIPHER_CTX_cleanup(s->enc_write_ctx);
          OPENSSL_free(s->enc_write_ctx);
          s->enc_write_ctx = NULL;
      }
  #ifndef OPENSSL_NO_COMP
      if (s->expand != NULL) {
          COMP_CTX_free(s->expand);
          s->expand = NULL;
      }
      if (s->compress != NULL) {
          COMP_CTX_free(s->compress);
          s->compress = NULL;
      }
  #endif
  }
  
  X509 *SSL_get_certificate(const SSL *s)
  {
      if (s->cert != NULL)
          return (s->cert->key->x509);
      else
          return (NULL);
  }
  
  EVP_PKEY *SSL_get_privatekey(const SSL *s)
  {
      if (s->cert != NULL)
          return (s->cert->key->privatekey);
      else
          return (NULL);
  }
  
  X509 *SSL_CTX_get0_certificate(const SSL_CTX *ctx)
  {
      if (ctx->cert != NULL)
          return ctx->cert->key->x509;
      else
          return NULL;
  }
  
  EVP_PKEY *SSL_CTX_get0_privatekey(const SSL_CTX *ctx)
  {
      if (ctx->cert != NULL)
          return ctx->cert->key->privatekey;
      else
          return NULL;
  }
  
  const SSL_CIPHER *SSL_get_current_cipher(const SSL *s)
  {
      if ((s->session != NULL) && (s->session->cipher != NULL))
          return (s->session->cipher);
      return (NULL);
  }
  
  #ifdef OPENSSL_NO_COMP
  const COMP_METHOD *SSL_get_current_compression(SSL *s)
  {
      return NULL;
  }
  
  const COMP_METHOD *SSL_get_current_expansion(SSL *s)
  {
      return NULL;
  }
  #else
  
  const COMP_METHOD *SSL_get_current_compression(SSL *s)
  {
      if (s->compress != NULL)
          return (s->compress->meth);
      return (NULL);
  }
  
  const COMP_METHOD *SSL_get_current_expansion(SSL *s)
  {
      if (s->expand != NULL)
          return (s->expand->meth);
      return (NULL);
  }
  #endif
  
  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);
      }
      (void)BIO_reset(bbio);
  /*      if (!BIO_set_write_buffer_size(bbio,16*1024)) */
      if (!BIO_set_read_buffer_size(bbio, 1)) {
          SSLerr(SSL_F_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);
  #ifdef REF_CHECK                /* not the usual REF_CHECK, but this avoids
                                   * adding one more preprocessor symbol */
          assert(s->wbio != NULL);
  #endif
      }
      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)
  {
      CERT *ocert = ssl->cert;
      if (ssl->ctx == ctx)
          return ssl->ctx;
  #ifndef OPENSSL_NO_TLSEXT
      if (ctx == NULL)
          ctx = ssl->initial_ctx;
  #endif
      ssl->cert = ssl_cert_dup(ctx->cert);
      if (ocert) {
          int i;
          /* Preserve any already negotiated parameters */
          if (ssl->server) {
              ssl->cert->peer_sigalgs = ocert->peer_sigalgs;
              ssl->cert->peer_sigalgslen = ocert->peer_sigalgslen;
              ocert->peer_sigalgs = NULL;
              ssl->cert->ciphers_raw = ocert->ciphers_raw;
              ssl->cert->ciphers_rawlen = ocert->ciphers_rawlen;
              ocert->ciphers_raw = NULL;
          }
          for (i = 0; i < SSL_PKEY_NUM; i++) {
              ssl->cert->pkeys[i].digest = ocert->pkeys[i].digest;
          }
  #ifndef OPENSSL_NO_TLSEXT
          ssl->cert->alpn_proposed = ocert->alpn_proposed;
          ssl->cert->alpn_proposed_len = ocert->alpn_proposed_len;
          ocert->alpn_proposed = NULL;
          ssl->cert->alpn_sent = ocert->alpn_sent;
  
          if (!custom_exts_copy_flags(&ssl->cert->srv_ext, &ocert->srv_ext))
              return NULL;
  #endif
          ssl_cert_free(ocert);
      }
  
      /*
       * Program invariant: |sid_ctx| has fixed size (SSL_MAX_SID_CTX_LENGTH),
       * so setter APIs must prevent invalid lengths from entering the system.
       */
      OPENSSL_assert(ssl->sid_ctx_length <= sizeof(ssl->sid_ctx));
  
      /*
       * If the session ID context matches that of the parent SSL_CTX,
       * inherit it from the new SSL_CTX as well. If however the context does
       * not match (i.e., it was set per-ssl with SSL_set_session_id_context),
       * leave it unchanged.
       */
      if ((ssl->ctx != NULL) &&
          (ssl->sid_ctx_length == ssl->ctx->sid_ctx_length) &&
          (memcmp(ssl->sid_ctx, ssl->ctx->sid_ctx, ssl->sid_ctx_length) == 0)) {
          ssl->sid_ctx_length = ctx->sid_ctx_length;
          memcpy(&ssl->sid_ctx, &ctx->sid_ctx, sizeof(ssl->sid_ctx));
      }
  
      CRYPTO_add(&ctx->references, 1, CRYPTO_LOCK_SSL_CTX);
      if (ssl->ctx != NULL)
          SSL_CTX_free(ssl->ctx); /* decrement reference count */
      ssl->ctx = ctx;
  
      return (ssl->ctx);
  }
  
  #ifndef OPENSSL_NO_STDIO
  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));
  }
  #endif
  
  void SSL_set_info_callback(SSL *ssl,
                             void (*cb) (const SSL *ssl, int type, int val))
  {
      ssl->info_callback = cb;
  }
  
  /*
   * One compiler (Diab DCC) doesn't like argument names in returned function
   * pointer.
   */
  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)
  {
      ssl->state = 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)
  {
      return CRYPTO_get_ex_new_index(CRYPTO_EX_INDEX_SSL, argl, argp,
                                     new_func, dup_func, free_func);
  }
  
  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)
  {
      return CRYPTO_get_ex_new_index(CRYPTO_EX_INDEX_SSL_CTX, argl, argp,
                                     new_func, dup_func, free_func);
  }
  
  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));
  }
  
  int ssl_ok(SSL *s)
  {
      return (1);
  }
  
  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)
  {
      if (ctx->cert_store != NULL)
          X509_STORE_free(ctx->cert_store);
      ctx->cert_store = store;
  }
  
  int SSL_want(const SSL *s)
  {
      return (s->rwstate);
  }
  
  /**
   * \brief Set the callback for generating temporary RSA keys.
   * \param ctx the SSL context.
   * \param cb the callback
   */
  
  #ifndef OPENSSL_NO_RSA
  void SSL_CTX_set_tmp_rsa_callback(SSL_CTX *ctx, RSA *(*cb) (SSL *ssl,
                                                              int is_export,
                                                              int keylength))
  {
      SSL_CTX_callback_ctrl(ctx, SSL_CTRL_SET_TMP_RSA_CB, (void (*)(void))cb);
  }
  
  void SSL_set_tmp_rsa_callback(SSL *ssl, RSA *(*cb) (SSL *ssl,
                                                      int is_export,
                                                      int keylength))
  {
      SSL_callback_ctrl(ssl, SSL_CTRL_SET_TMP_RSA_CB, (void (*)(void))cb);
  }
  #endif
  
  #ifdef DOXYGEN
  /**
   * \brief The RSA temporary key callback function.
   * \param ssl the SSL session.
   * \param is_export \c TRUE if the temp RSA key is for an export ciphersuite.
   * \param keylength if \c is_export is \c TRUE, then \c keylength is the size
   * of the required key in bits.
   * \return the temporary RSA key.
   * \sa SSL_CTX_set_tmp_rsa_callback, SSL_set_tmp_rsa_callback
   */
  
  RSA *cb(SSL *ssl, int is_export, int keylength)
  {
  }
  #endif
  
  /**
   * \brief Set the callback for generating temporary DH keys.
   * \param ctx the SSL context.
   * \param dh the callback
   */
  
  #ifndef OPENSSL_NO_DH
  void SSL_CTX_set_tmp_dh_callback(SSL_CTX *ctx,
                                   DH *(*dh) (SSL *ssl, int is_export,
                                              int keylength))
  {
      SSL_CTX_callback_ctrl(ctx, SSL_CTRL_SET_TMP_DH_CB, (void (*)(void))dh);
  }
  
  void SSL_set_tmp_dh_callback(SSL *ssl, DH *(*dh) (SSL *ssl, int is_export,
                                                    int keylength))
  {
      SSL_callback_ctrl(ssl, SSL_CTRL_SET_TMP_DH_CB, (void (*)(void))dh);
  }
  #endif
  
  #ifndef OPENSSL_NO_ECDH
  void SSL_CTX_set_tmp_ecdh_callback(SSL_CTX *ctx,
                                     EC_KEY *(*ecdh) (SSL *ssl, int is_export,
                                                      int keylength))
  {
      SSL_CTX_callback_ctrl(ctx, SSL_CTRL_SET_TMP_ECDH_CB,
                            (void (*)(void))ecdh);
  }
  
  void SSL_set_tmp_ecdh_callback(SSL *ssl,
                                 EC_KEY *(*ecdh) (SSL *ssl, int is_export,
                                                  int keylength))
  {
      SSL_callback_ctrl(ssl, SSL_CTRL_SET_TMP_ECDH_CB, (void (*)(void))ecdh);
  }
  #endif
  
  #ifndef OPENSSL_NO_PSK
  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) {
          SSLerr(SSL_F_SSL_CTX_USE_PSK_IDENTITY_HINT,
                 SSL_R_DATA_LENGTH_TOO_LONG);
          return 0;
      }
      if (ctx->psk_identity_hint != NULL)
          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 (s->session == NULL)
          return 1;               /* session not created yet, ignored */
  
      if (identity_hint != NULL && strlen(identity_hint) > PSK_MAX_IDENTITY_LEN) {
          SSLerr(SSL_F_SSL_USE_PSK_IDENTITY_HINT, SSL_R_DATA_LENGTH_TOO_LONG);
          return 0;
      }
      if (s->session->psk_identity_hint != NULL)
          OPENSSL_free(s->session->psk_identity_hint);
      if (identity_hint != NULL) {
          s->session->psk_identity_hint = BUF_strdup(identity_hint);
          if (s->session->psk_identity_hint == NULL)
              return 0;
      } else
          s->session->psk_identity_hint = NULL;
      return 1;
  }
  
  const char *SSL_get_psk_identity_hint(const SSL *s)
  {
      if (s == NULL || s->session == NULL)
          return NULL;
      return (s->session->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,
                                                       unsigned char *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,
                                                           unsigned char *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,
                                                       unsigned char *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,
                                                           unsigned char *psk,
                                                           unsigned int
                                                           max_psk_len))
  {
      ctx->psk_server_callback = cb;
  }
  #endif
  
  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))
  {
      SSL_CTX_callback_ctrl(ctx, SSL_CTRL_SET_MSG_CALLBACK, (void (*)(void))cb);
  }
  
  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_callback_ctrl(ssl, SSL_CTRL_SET_MSG_CALLBACK, (void (*)(void))cb);
  }
  
  /*
   * Allocates new EVP_MD_CTX and sets pointer to it into given pointer
   * vairable, freeing EVP_MD_CTX previously stored in that variable, if any.
   * If EVP_MD pointer is passed, initializes ctx with this md Returns newly
   * allocated ctx;
   */
  
  EVP_MD_CTX *ssl_replace_hash(EVP_MD_CTX **hash, const EVP_MD *md)
  {
      ssl_clear_hash_ctx(hash);
      *hash = EVP_MD_CTX_create();
      if (*hash == NULL || (md && EVP_DigestInit_ex(*hash, md, NULL) <= 0)) {
          EVP_MD_CTX_destroy(*hash);
          *hash = NULL;
          return NULL;
      }
      return *hash;
  }
  
  void ssl_clear_hash_ctx(EVP_MD_CTX **hash)
  {
  
      if (*hash)
          EVP_MD_CTX_destroy(*hash);
      *hash = NULL;
  }
  
  void SSL_set_debug(SSL *s, int debug)
  {
      s->debug = debug;
  }
  
  int SSL_cache_hit(SSL *s)
  {
      return s->hit;
  }
  
  int SSL_is_server(SSL *s)
  {
      return s->server;
  }
  
  #if defined(_WINDLL) && defined(OPENSSL_SYS_WIN16)
  # include "../crypto/bio/bss_file.c"
  #endif
  
  IMPLEMENT_STACK_OF(SSL_CIPHER)
  IMPLEMENT_STACK_OF(SSL_COMP)
  IMPLEMENT_OBJ_BSEARCH_GLOBAL_CMP_FN(SSL_CIPHER, SSL_CIPHER, ssl_cipher_id);
  