text: #ifndef HEADER_CURL_SCHANNEL_H
  #define HEADER_CURL_SCHANNEL_H
  /***************************************************************************
   *                                  _   _ ____  _
   *  Project                     ___| | | |  _ \| |
   *                             / __| | | | |_) | |
   *                            | (__| |_| |  _ <| |___
   *                             \___|\___/|_| \_\_____|
   *
   * Copyright (C) 2012, Marc Hoersken, <info@marc-hoersken.de>, et al.
   * Copyright (C) 2012 - 2017, Daniel Stenberg, <daniel@haxx.se>, et al.
   *
   * This software is licensed as described in the file COPYING, which
   * you should have received as part of this distribution. The terms
   * are also available at https://curl.haxx.se/docs/copyright.html.
   *
   * You may opt to use, copy, modify, merge, publish, distribute and/or sell
   * copies of the Software, and permit persons to whom the Software is
   * furnished to do so, under the terms of the COPYING file.
   *
   * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
   * KIND, either express or implied.
   *
   ***************************************************************************/
  #include "curl_setup.h"
  
  #ifdef USE_SCHANNEL
  
  #include <schnlsp.h>
  #include <schannel.h>
  #include "curl_sspi.h"
  
  #include "urldata.h"
  
  extern const struct Curl_ssl Curl_ssl_schannel;
  
  CURLcode verify_certificate(struct connectdata *conn, int sockindex);
  
  /* structs to expose only in schannel.c and schannel_verify.c */
  #ifdef EXPOSE_SCHANNEL_INTERNAL_STRUCTS
  struct curl_schannel_cred {
    CredHandle cred_handle;
    TimeStamp time_stamp;
    int refcount;
  };
  
  struct curl_schannel_ctxt {
    CtxtHandle ctxt_handle;
    TimeStamp time_stamp;
  };
  
  struct ssl_backend_data {
    struct curl_schannel_cred *cred;
    struct curl_schannel_ctxt *ctxt;
    SecPkgContext_StreamSizes stream_sizes;
    size_t encdata_length, decdata_length;
    size_t encdata_offset, decdata_offset;
    unsigned char *encdata_buffer, *decdata_buffer;
    /* encdata_is_incomplete: if encdata contains only a partial record that
       can't be decrypted without another Curl_read_plain (that is, status is
       SEC_E_INCOMPLETE_MESSAGE) then set this true. after Curl_read_plain writes
       more bytes into encdata then set this back to false. */
    bool encdata_is_incomplete;
    unsigned long req_flags, ret_flags;
    CURLcode recv_unrecoverable_err; /* schannel_recv had an unrecoverable err */
    bool recv_sspi_close_notify; /* true if connection closed by close_notify */
    bool recv_connection_closed; /* true if connection closed, regardless how */
    bool use_alpn; /* true if ALPN is used for this connection */
    bool use_manual_cred_validation; /* true if manual cred validation is used */
  };
  #endif /* EXPOSE_SCHANNEL_INTERNAL_STRUCTS */
  
  #endif /* USE_SCHANNEL */
  #endif /* HEADER_CURL_SCHANNEL_H */
  