text: /***************************************************************************
   *                                  _   _ ____  _
   *  Project                     ___| | | |  _ \| |
   *                             / __| | | | |_) | |
   *                            | (__| |_| |  _ <| |___
   *                             \___|\___/|_| \_\_____|
   *
   * Copyright (C) 2012 - 2015, Daniel Stenberg, <daniel@haxx.se>, et al.
   * Copyright (C) 2009, 2011, Markus Moeller, <markus_moeller@compuserve.com>
   *
   * 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 http://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"
  
  #if defined(USE_WINDOWS_SSPI) && !defined(CURL_DISABLE_PROXY)
  
  #include "urldata.h"
  #include "sendf.h"
  #include "connect.h"
  #include "strerror.h"
  #include "timeval.h"
  #include "socks.h"
  #include "curl_sspi.h"
  #include "curl_multibyte.h"
  #include "warnless.h"
  #include "curl_printf.h"
  #include "curl_memory.h"
  /* The last #include file should be: */
  #include "memdebug.h"
  
  /*
   * Helper sspi error functions.
   */
  static int check_sspi_err(struct connectdata *conn,
                            SECURITY_STATUS status,
                            const char* function)
  {
    if(status != SEC_E_OK &&
       status != SEC_I_COMPLETE_AND_CONTINUE &&
       status != SEC_I_COMPLETE_NEEDED &&
       status != SEC_I_CONTINUE_NEEDED) {
      failf(conn->data, "SSPI error: %s failed: %s", function,
            Curl_sspi_strerror(conn, status));
      return 1;
    }
    return 0;
  }
  
  /* This is the SSPI-using version of this function */
  CURLcode Curl_SOCKS5_gssapi_negotiate(int sockindex,
                                        struct connectdata *conn)
  {
    struct SessionHandle *data = conn->data;
    curl_socket_t sock = conn->sock[sockindex];
    CURLcode code;
    ssize_t actualread;
    ssize_t written;
    int result;
    /* Needs GSS-API authentication */
    SECURITY_STATUS status;
    unsigned long sspi_ret_flags = 0;
    int gss_enc;
    SecBuffer sspi_send_token, sspi_recv_token, sspi_w_token[3];
    SecBufferDesc input_desc, output_desc, wrap_desc;
    SecPkgContext_Sizes sspi_sizes;
    CredHandle cred_handle;
    CtxtHandle sspi_context;
    PCtxtHandle context_handle = NULL;
    SecPkgCredentials_Names names;
    TimeStamp expiry;
    char *service_name = NULL;
    unsigned short us_length;
    unsigned long qop;
    unsigned char socksreq[4]; /* room for GSS-API exchange header only */
    char *service = data->set.str[STRING_SOCKS5_GSSAPI_SERVICE];
  
    /*   GSS-API request looks like
     * +----+------+-----+----------------+
     * |VER | MTYP | LEN |     TOKEN      |
     * +----+------+----------------------+
     * | 1  |  1   |  2  | up to 2^16 - 1 |
     * +----+------+-----+----------------+
     */
  
    /* prepare service name */
    if(strchr(service, '/')) {
      service_name = malloc(strlen(service));
      if(!service_name)
        return CURLE_OUT_OF_MEMORY;
      memcpy(service_name, service, strlen(service));
    }
    else {
      service_name = malloc(strlen(service) + strlen(conn->proxy.name) + 2);
      if(!service_name)
        return CURLE_OUT_OF_MEMORY;
      snprintf(service_name, strlen(service) +strlen(conn->proxy.name)+2,
               "%s/%s", service, conn->proxy.name);
    }
  
    input_desc.cBuffers = 1;
    input_desc.pBuffers = &sspi_recv_token;
    input_desc.ulVersion = SECBUFFER_VERSION;
  
    sspi_recv_token.BufferType = SECBUFFER_TOKEN;
    sspi_recv_token.cbBuffer = 0;
    sspi_recv_token.pvBuffer = NULL;
  
    output_desc.cBuffers = 1;
    output_desc.pBuffers = &sspi_send_token;
    output_desc.ulVersion = SECBUFFER_VERSION;
  
    sspi_send_token.BufferType = SECBUFFER_TOKEN;
    sspi_send_token.cbBuffer = 0;
    sspi_send_token.pvBuffer = NULL;
  
    wrap_desc.cBuffers = 3;
    wrap_desc.pBuffers = sspi_w_token;
    wrap_desc.ulVersion = SECBUFFER_VERSION;
  
    cred_handle.dwLower = 0;
    cred_handle.dwUpper = 0;
  
    status = s_pSecFn->AcquireCredentialsHandle(NULL,
                                                (TCHAR *) TEXT("Kerberos"),
                                                SECPKG_CRED_OUTBOUND,
                                                NULL,
                                                NULL,
                                                NULL,
                                                NULL,
                                                &cred_handle,
                                                &expiry);
  
    if(check_sspi_err(conn, status, "AcquireCredentialsHandle")) {
      failf(data, "Failed to acquire credentials.");
      free(service_name);
      s_pSecFn->FreeCredentialsHandle(&cred_handle);
      return CURLE_COULDNT_CONNECT;
    }
  
    /* As long as we need to keep sending some context info, and there's no  */
    /* errors, keep sending it...                                            */
    for(;;) {
      TCHAR *sname;
  
      sname = Curl_convert_UTF8_to_tchar(service_name);
      if(!sname)
        return CURLE_OUT_OF_MEMORY;
  
      status = s_pSecFn->InitializeSecurityContext(&cred_handle,
                                                   context_handle,
                                                   sname,
                                                   ISC_REQ_MUTUAL_AUTH |
                                                   ISC_REQ_ALLOCATE_MEMORY |
                                                   ISC_REQ_CONFIDENTIALITY |
                                                   ISC_REQ_REPLAY_DETECT,
                                                   0,
                                                   SECURITY_NATIVE_DREP,
                                                   &input_desc,
                                                   0,
                                                   &sspi_context,
                                                   &output_desc,
                                                   &sspi_ret_flags,
                                                   &expiry);
  
      Curl_unicodefree(sname);
  
      if(sspi_recv_token.pvBuffer) {
        s_pSecFn->FreeContextBuffer(sspi_recv_token.pvBuffer);
        sspi_recv_token.pvBuffer = NULL;
        sspi_recv_token.cbBuffer = 0;
      }
  
      if(check_sspi_err(conn, status, "InitializeSecurityContext")) {
        free(service_name);
        s_pSecFn->FreeCredentialsHandle(&cred_handle);
        s_pSecFn->DeleteSecurityContext(&sspi_context);
        if(sspi_recv_token.pvBuffer)
          s_pSecFn->FreeContextBuffer(sspi_recv_token.pvBuffer);
        failf(data, "Failed to initialise security context.");
        return CURLE_COULDNT_CONNECT;
      }
  
      if(sspi_send_token.cbBuffer != 0) {
        socksreq[0] = 1;    /* GSS-API subnegotiation version */
        socksreq[1] = 1;    /* authentication message type */
        us_length = htons((short)sspi_send_token.cbBuffer);
        memcpy(socksreq+2, &us_length, sizeof(short));
  
        code = Curl_write_plain(conn, sock, (char *)socksreq, 4, &written);
        if(code || (4 != written)) {
          failf(data, "Failed to send SSPI authentication request.");
          free(service_name);
          if(sspi_send_token.pvBuffer)
            s_pSecFn->FreeContextBuffer(sspi_send_token.pvBuffer);
          if(sspi_recv_token.pvBuffer)
            s_pSecFn->FreeContextBuffer(sspi_recv_token.pvBuffer);
          s_pSecFn->FreeCredentialsHandle(&cred_handle);
          s_pSecFn->DeleteSecurityContext(&sspi_context);
          return CURLE_COULDNT_CONNECT;
        }
  
        code = Curl_write_plain(conn, sock, (char *)sspi_send_token.pvBuffer,
                                sspi_send_token.cbBuffer, &written);
        if(code || (sspi_send_token.cbBuffer != (size_t)written)) {
          failf(data, "Failed to send SSPI authentication token.");
          free(service_name);
          if(sspi_send_token.pvBuffer)
            s_pSecFn->FreeContextBuffer(sspi_send_token.pvBuffer);
          if(sspi_recv_token.pvBuffer)
            s_pSecFn->FreeContextBuffer(sspi_recv_token.pvBuffer);
          s_pSecFn->FreeCredentialsHandle(&cred_handle);
          s_pSecFn->DeleteSecurityContext(&sspi_context);
          return CURLE_COULDNT_CONNECT;
        }
  
      }
  
      if(sspi_send_token.pvBuffer) {
        s_pSecFn->FreeContextBuffer(sspi_send_token.pvBuffer);
        sspi_send_token.pvBuffer = NULL;
      }
      sspi_send_token.cbBuffer = 0;
  
      if(sspi_recv_token.pvBuffer) {
        s_pSecFn->FreeContextBuffer(sspi_recv_token.pvBuffer);
        sspi_recv_token.pvBuffer = NULL;
      }
      sspi_recv_token.cbBuffer = 0;
  
      if(status != SEC_I_CONTINUE_NEEDED)
        break;
  
      /* analyse response */
  
      /*   GSS-API response looks like
       * +----+------+-----+----------------+
       * |VER | MTYP | LEN |     TOKEN      |
       * +----+------+----------------------+
       * | 1  |  1   |  2  | up to 2^16 - 1 |
       * +----+------+-----+----------------+
       */
  
      result = Curl_blockread_all(conn, sock, (char *)socksreq, 4, &actualread);
      if(result || (actualread != 4)) {
        failf(data, "Failed to receive SSPI authentication response.");
        free(service_name);
        s_pSecFn->FreeCredentialsHandle(&cred_handle);
        s_pSecFn->DeleteSecurityContext(&sspi_context);
        return CURLE_COULDNT_CONNECT;
      }
  
      /* ignore the first (VER) byte */
      if(socksreq[1] == 255) { /* status / message type */
        failf(data, "User was rejected by the SOCKS5 server (%u %u).",
              (unsigned int)socksreq[0], (unsigned int)socksreq[1]);
        free(service_name);
        s_pSecFn->FreeCredentialsHandle(&cred_handle);
        s_pSecFn->DeleteSecurityContext(&sspi_context);
        return CURLE_COULDNT_CONNECT;
      }
  
      if(socksreq[1] != 1) { /* status / messgae type */
        failf(data, "Invalid SSPI authentication response type (%u %u).",
              (unsigned int)socksreq[0], (unsigned int)socksreq[1]);
        free(service_name);
        s_pSecFn->FreeCredentialsHandle(&cred_handle);
        s_pSecFn->DeleteSecurityContext(&sspi_context);
        return CURLE_COULDNT_CONNECT;
      }
  
      memcpy(&us_length, socksreq+2, sizeof(short));
      us_length = ntohs(us_length);
  
      sspi_recv_token.cbBuffer = us_length;
      sspi_recv_token.pvBuffer = malloc(us_length);
  
      if(!sspi_recv_token.pvBuffer) {
        free(service_name);
        s_pSecFn->FreeCredentialsHandle(&cred_handle);
        s_pSecFn->DeleteSecurityContext(&sspi_context);
        return CURLE_OUT_OF_MEMORY;
      }
      result = Curl_blockread_all(conn, sock, (char *)sspi_recv_token.pvBuffer,
                                  sspi_recv_token.cbBuffer, &actualread);
  
      if(result || (actualread != us_length)) {
        failf(data, "Failed to receive SSPI authentication token.");
        free(service_name);
        if(sspi_recv_token.pvBuffer)
          s_pSecFn->FreeContextBuffer(sspi_recv_token.pvBuffer);
        s_pSecFn->FreeCredentialsHandle(&cred_handle);
        s_pSecFn->DeleteSecurityContext(&sspi_context);
        return CURLE_COULDNT_CONNECT;
      }
  
      context_handle = &sspi_context;
    }
  
    free(service_name);
  
    /* Everything is good so far, user was authenticated! */
    status = s_pSecFn->QueryCredentialsAttributes(&cred_handle,
                                                  SECPKG_CRED_ATTR_NAMES,
                                                  &names);
    s_pSecFn->FreeCredentialsHandle(&cred_handle);
    if(check_sspi_err(conn, status, "QueryCredentialAttributes")) {
      s_pSecFn->DeleteSecurityContext(&sspi_context);
      s_pSecFn->FreeContextBuffer(names.sUserName);
      failf(data, "Failed to determine user name.");
      return CURLE_COULDNT_CONNECT;
    }
    infof(data, "SOCKS5 server authencticated user %s with GSS-API.\n",
          names.sUserName);
    s_pSecFn->FreeContextBuffer(names.sUserName);
  
    /* Do encryption */
    socksreq[0] = 1;    /* GSS-API subnegotiation version */
    socksreq[1] = 2;    /* encryption message type */
  
    gss_enc = 0; /* no data protection */
    /* do confidentiality protection if supported */
    if(sspi_ret_flags & ISC_REQ_CONFIDENTIALITY)
      gss_enc = 2;
    /* else do integrity protection */
    else if(sspi_ret_flags & ISC_REQ_INTEGRITY)
      gss_enc = 1;
  
    infof(data, "SOCKS5 server supports GSS-API %s data protection.\n",
          (gss_enc==0)?"no":((gss_enc==1)?"integrity":"confidentiality") );
    /* force to no data protection, avoid encryption/decryption for now */
    gss_enc = 0;
    /*
     * Sending the encryption type in clear seems wrong. It should be
     * protected with gss_seal()/gss_wrap(). See RFC1961 extract below
     * The NEC reference implementations on which this is based is
     * therefore at fault
     *
     *  +------+------+------+.......................+
     *  + ver  | mtyp | len  |   token               |
     *  +------+------+------+.......................+
     *  + 0x01 | 0x02 | 0x02 | up to 2^16 - 1 octets |
     *  +------+------+------+.......................+
     *
     *   Where:
     *
     *  - "ver" is the protocol version number, here 1 to represent the
     *    first version of the SOCKS/GSS-API protocol
     *
     *  - "mtyp" is the message type, here 2 to represent a protection
     *    -level negotiation message
     *
     *  - "len" is the length of the "token" field in octets
     *
     *  - "token" is the GSS-API encapsulated protection level
     *
     * The token is produced by encapsulating an octet containing the
     * required protection level using gss_seal()/gss_wrap() with conf_req
     * set to FALSE.  The token is verified using gss_unseal()/
     * gss_unwrap().
     *
     */
  
    if(data->set.socks5_gssapi_nec) {
      us_length = htons((short)1);
      memcpy(socksreq+2, &us_length, sizeof(short));
    }
    else {
      status = s_pSecFn->QueryContextAttributes(&sspi_context,
                                                SECPKG_ATTR_SIZES,
                                                &sspi_sizes);
      if(check_sspi_err(conn, status, "QueryContextAttributes")) {
        s_pSecFn->DeleteSecurityContext(&sspi_context);
        failf(data, "Failed to query security context attributes.");
        return CURLE_COULDNT_CONNECT;
      }
  
      sspi_w_token[0].cbBuffer = sspi_sizes.cbSecurityTrailer;
      sspi_w_token[0].BufferType = SECBUFFER_TOKEN;
      sspi_w_token[0].pvBuffer = malloc(sspi_sizes.cbSecurityTrailer);
  
      if(!sspi_w_token[0].pvBuffer) {
        s_pSecFn->DeleteSecurityContext(&sspi_context);
        return CURLE_OUT_OF_MEMORY;
      }
  
      sspi_w_token[1].cbBuffer = 1;
      sspi_w_token[1].pvBuffer = malloc(1);
      if(!sspi_w_token[1].pvBuffer) {
        s_pSecFn->FreeContextBuffer(sspi_w_token[0].pvBuffer);
        s_pSecFn->DeleteSecurityContext(&sspi_context);
        return CURLE_OUT_OF_MEMORY;
      }
  
      memcpy(sspi_w_token[1].pvBuffer, &gss_enc, 1);
      sspi_w_token[2].BufferType = SECBUFFER_PADDING;
      sspi_w_token[2].cbBuffer = sspi_sizes.cbBlockSize;
      sspi_w_token[2].pvBuffer = malloc(sspi_sizes.cbBlockSize);
      if(!sspi_w_token[2].pvBuffer) {
        s_pSecFn->FreeContextBuffer(sspi_w_token[0].pvBuffer);
        s_pSecFn->FreeContextBuffer(sspi_w_token[1].pvBuffer);
        s_pSecFn->DeleteSecurityContext(&sspi_context);
        return CURLE_OUT_OF_MEMORY;
      }
      status = s_pSecFn->EncryptMessage(&sspi_context,
                                        KERB_WRAP_NO_ENCRYPT,
                                        &wrap_desc,
                                        0);
      if(check_sspi_err(conn, status, "EncryptMessage")) {
        s_pSecFn->FreeContextBuffer(sspi_w_token[0].pvBuffer);
        s_pSecFn->FreeContextBuffer(sspi_w_token[1].pvBuffer);
        s_pSecFn->FreeContextBuffer(sspi_w_token[2].pvBuffer);
        s_pSecFn->DeleteSecurityContext(&sspi_context);
        failf(data, "Failed to query security context attributes.");
        return CURLE_COULDNT_CONNECT;
      }
      sspi_send_token.cbBuffer = sspi_w_token[0].cbBuffer
        + sspi_w_token[1].cbBuffer
        + sspi_w_token[2].cbBuffer;
      sspi_send_token.pvBuffer = malloc(sspi_send_token.cbBuffer);
      if(!sspi_send_token.pvBuffer) {
        s_pSecFn->FreeContextBuffer(sspi_w_token[0].pvBuffer);
        s_pSecFn->FreeContextBuffer(sspi_w_token[1].pvBuffer);
        s_pSecFn->FreeContextBuffer(sspi_w_token[2].pvBuffer);
        s_pSecFn->DeleteSecurityContext(&sspi_context);
        return CURLE_OUT_OF_MEMORY;
      }
  
      memcpy(sspi_send_token.pvBuffer, sspi_w_token[0].pvBuffer,
             sspi_w_token[0].cbBuffer);
      memcpy((PUCHAR) sspi_send_token.pvBuffer +(int)sspi_w_token[0].cbBuffer,
             sspi_w_token[1].pvBuffer, sspi_w_token[1].cbBuffer);
      memcpy((PUCHAR) sspi_send_token.pvBuffer
             +sspi_w_token[0].cbBuffer
             +sspi_w_token[1].cbBuffer,
             sspi_w_token[2].pvBuffer, sspi_w_token[2].cbBuffer);
  
      s_pSecFn->FreeContextBuffer(sspi_w_token[0].pvBuffer);
      sspi_w_token[0].pvBuffer = NULL;
      sspi_w_token[0].cbBuffer = 0;
      s_pSecFn->FreeContextBuffer(sspi_w_token[1].pvBuffer);
      sspi_w_token[1].pvBuffer = NULL;
      sspi_w_token[1].cbBuffer = 0;
      s_pSecFn->FreeContextBuffer(sspi_w_token[2].pvBuffer);
      sspi_w_token[2].pvBuffer = NULL;
      sspi_w_token[2].cbBuffer = 0;
  
      us_length = htons((short)sspi_send_token.cbBuffer);
      memcpy(socksreq+2, &us_length, sizeof(short));
    }
  
    code = Curl_write_plain(conn, sock, (char *)socksreq, 4, &written);
    if(code || (4 != written)) {
      failf(data, "Failed to send SSPI encryption request.");
      if(sspi_send_token.pvBuffer)
        s_pSecFn->FreeContextBuffer(sspi_send_token.pvBuffer);
      s_pSecFn->DeleteSecurityContext(&sspi_context);
      return CURLE_COULDNT_CONNECT;
    }
  
    if(data->set.socks5_gssapi_nec) {
      memcpy(socksreq, &gss_enc, 1);
      code = Curl_write_plain(conn, sock, (char *)socksreq, 1, &written);
      if(code || (1 != written)) {
        failf(data, "Failed to send SSPI encryption type.");
        s_pSecFn->DeleteSecurityContext(&sspi_context);
        return CURLE_COULDNT_CONNECT;
      }
    }
    else {
      code = Curl_write_plain(conn, sock, (char *)sspi_send_token.pvBuffer,
                              sspi_send_token.cbBuffer, &written);
      if(code || (sspi_send_token.cbBuffer != (size_t)written)) {
        failf(data, "Failed to send SSPI encryption type.");
        if(sspi_send_token.pvBuffer)
          s_pSecFn->FreeContextBuffer(sspi_send_token.pvBuffer);
        s_pSecFn->DeleteSecurityContext(&sspi_context);
        return CURLE_COULDNT_CONNECT;
      }
      if(sspi_send_token.pvBuffer)
        s_pSecFn->FreeContextBuffer(sspi_send_token.pvBuffer);
    }
  
    result = Curl_blockread_all(conn, sock, (char *)socksreq, 4, &actualread);
    if(result || (actualread != 4)) {
      failf(data, "Failed to receive SSPI encryption response.");
      s_pSecFn->DeleteSecurityContext(&sspi_context);
      return CURLE_COULDNT_CONNECT;
    }
  
    /* ignore the first (VER) byte */
    if(socksreq[1] == 255) { /* status / message type */
      failf(data, "User was rejected by the SOCKS5 server (%u %u).",
            (unsigned int)socksreq[0], (unsigned int)socksreq[1]);
      s_pSecFn->DeleteSecurityContext(&sspi_context);
      return CURLE_COULDNT_CONNECT;
    }
  
    if(socksreq[1] != 2) { /* status / message type */
      failf(data, "Invalid SSPI encryption response type (%u %u).",
            (unsigned int)socksreq[0], (unsigned int)socksreq[1]);
      s_pSecFn->DeleteSecurityContext(&sspi_context);
      return CURLE_COULDNT_CONNECT;
    }
  
    memcpy(&us_length, socksreq+2, sizeof(short));
    us_length = ntohs(us_length);
  
    sspi_w_token[0].cbBuffer = us_length;
    sspi_w_token[0].pvBuffer = malloc(us_length);
    if(!sspi_w_token[0].pvBuffer) {
      s_pSecFn->DeleteSecurityContext(&sspi_context);
      return CURLE_OUT_OF_MEMORY;
    }
  
    result = Curl_blockread_all(conn, sock, (char *)sspi_w_token[0].pvBuffer,
                                sspi_w_token[0].cbBuffer, &actualread);
  
    if(result || (actualread != us_length)) {
      failf(data, "Failed to receive SSPI encryption type.");
      s_pSecFn->FreeContextBuffer(sspi_w_token[0].pvBuffer);
      s_pSecFn->DeleteSecurityContext(&sspi_context);
      return CURLE_COULDNT_CONNECT;
    }
  
  
    if(!data->set.socks5_gssapi_nec) {
      wrap_desc.cBuffers = 2;
      sspi_w_token[0].BufferType = SECBUFFER_STREAM;
      sspi_w_token[1].BufferType = SECBUFFER_DATA;
      sspi_w_token[1].cbBuffer = 0;
      sspi_w_token[1].pvBuffer = NULL;
  
      status = s_pSecFn->DecryptMessage(&sspi_context,
                                        &wrap_desc,
                                        0,
                                        &qop);
  
      if(check_sspi_err(conn, status, "DecryptMessage")) {
        if(sspi_w_token[0].pvBuffer)
          s_pSecFn->FreeContextBuffer(sspi_w_token[0].pvBuffer);
        if(sspi_w_token[1].pvBuffer)
          s_pSecFn->FreeContextBuffer(sspi_w_token[1].pvBuffer);
        s_pSecFn->DeleteSecurityContext(&sspi_context);
        failf(data, "Failed to query security context attributes.");
        return CURLE_COULDNT_CONNECT;
      }
  
      if(sspi_w_token[1].cbBuffer != 1) {
        failf(data, "Invalid SSPI encryption response length (%lu).",
              (unsigned long)sspi_w_token[1].cbBuffer);
        if(sspi_w_token[0].pvBuffer)
          s_pSecFn->FreeContextBuffer(sspi_w_token[0].pvBuffer);
        if(sspi_w_token[1].pvBuffer)
          s_pSecFn->FreeContextBuffer(sspi_w_token[1].pvBuffer);
        s_pSecFn->DeleteSecurityContext(&sspi_context);
        return CURLE_COULDNT_CONNECT;
      }
  
      memcpy(socksreq, sspi_w_token[1].pvBuffer, sspi_w_token[1].cbBuffer);
      s_pSecFn->FreeContextBuffer(sspi_w_token[0].pvBuffer);
      s_pSecFn->FreeContextBuffer(sspi_w_token[1].pvBuffer);
    }
    else {
      if(sspi_w_token[0].cbBuffer != 1) {
        failf(data, "Invalid SSPI encryption response length (%lu).",
              (unsigned long)sspi_w_token[0].cbBuffer);
        s_pSecFn->FreeContextBuffer(sspi_w_token[0].pvBuffer);
        s_pSecFn->DeleteSecurityContext(&sspi_context);
        return CURLE_COULDNT_CONNECT;
      }
      memcpy(socksreq, sspi_w_token[0].pvBuffer, sspi_w_token[0].cbBuffer);
      s_pSecFn->FreeContextBuffer(sspi_w_token[0].pvBuffer);
    }
  
    infof(data, "SOCKS5 access with%s protection granted.\n",
          (socksreq[0]==0)?"out GSS-API data":
          ((socksreq[0]==1)?" GSS-API integrity":" GSS-API confidentiality"));
  
    /* For later use if encryption is required
       conn->socks5_gssapi_enctype = socksreq[0];
       if(socksreq[0] != 0)
         conn->socks5_sspi_context = sspi_context;
       else {
         s_pSecFn->DeleteSecurityContext(&sspi_context);
         conn->socks5_sspi_context = sspi_context;
       }
    */
    return CURLE_OK;
  }
  #endif
  