curl_schannel.c

    /* move remaining decrypted data forward to the beginning of buffer */
    memmove(connssl->decdata_buffer, connssl->decdata_buffer + size,
            connssl->decdata_offset - size);
    connssl->decdata_offset -= size;
  }

  /* check if the server closed the connection */
  if(ret <= 0 && ( /* special check for Windows 2000 Professional */
      sspi_status == SEC_I_CONTEXT_EXPIRED || (sspi_status == SEC_E_OK &&
        connssl->encdata_offset > 0 && connssl->encdata_buffer[0] == 0x15))) {
    infof(data, "schannel: server closed the connection\n");
    *err = CURLE_OK;
    return 0;
  }

  /* check if something went wrong and we need to return an error */
  if(ret < 0 && sspi_status != SEC_E_OK) {
    infof(data, "schannel: failed to read data from server: %s\n",
          Curl_sspi_strerror(conn, sspi_status));
    *err = CURLE_RECV_ERROR;
    return -1;
  }

  return ret;
}

CURLcode
Curl_schannel_connect_nonblocking(struct connectdata *conn, int sockindex,
                                  bool *done)
{
  return schannel_connect_common(conn, sockindex, TRUE, done);
}

CURLcode
Curl_schannel_connect(struct connectdata *conn, int sockindex)
{
  CURLcode retcode;
  bool done = FALSE;

  retcode = schannel_connect_common(conn, sockindex, FALSE, &done);
  if(retcode)
    return retcode;

  DEBUGASSERT(done);

  return CURLE_OK;
}

bool Curl_schannel_data_pending(const struct connectdata *conn, int sockindex)
{
  const struct ssl_connect_data *connssl = &conn->ssl[sockindex];

  if(connssl->use) /* SSL/TLS is in use */
    return (connssl->encdata_offset > 0 ||
            connssl->decdata_offset > 0 ) ? TRUE : FALSE;
  else
    return FALSE;
}

void Curl_schannel_close(struct connectdata *conn, int sockindex)
{
  if(conn->ssl[sockindex].use)
    /* if the SSL/TLS channel hasn't been shut down yet, do that now. */
    Curl_ssl_shutdown(conn, sockindex);
}

int Curl_schannel_shutdown(struct connectdata *conn, int sockindex)
{
  /* See http://msdn.microsoft.com/en-us/library/windows/desktop/aa380138.aspx
   * Shutting Down an Schannel Connection
   */
  struct SessionHandle *data = conn->data;
  struct ssl_connect_data *connssl = &conn->ssl[sockindex];

  infof(data, "schannel: shutting down SSL/TLS connection with %s port %hu\n",
        conn->host.name, conn->remote_port);

  if(connssl->ctxt) {
    SecBufferDesc BuffDesc;
    SecBuffer Buffer;
    SECURITY_STATUS sspi_status;
    SecBuffer outbuf;
    SecBufferDesc outbuf_desc;
    CURLcode code;
    TCHAR *host_name;
    DWORD dwshut = SCHANNEL_SHUTDOWN;

    InitSecBuffer(&Buffer, SECBUFFER_TOKEN, &dwshut, sizeof(dwshut));
    InitSecBufferDesc(&BuffDesc, &Buffer, 1);

    sspi_status = s_pSecFn->ApplyControlToken(&connssl->ctxt->ctxt_handle,
                                              &BuffDesc);

    if(sspi_status != SEC_E_OK)
      failf(data, "schannel: ApplyControlToken failure: %s",
            Curl_sspi_strerror(conn, sspi_status));

#ifdef UNICODE
    host_name = Curl_convert_UTF8_to_wchar(conn->host.name);
    if(!host_name)
      return CURLE_OUT_OF_MEMORY;
#else
    host_name = conn->host.name;
#endif

    /* setup output buffer */
    InitSecBuffer(&outbuf, SECBUFFER_EMPTY, NULL, 0);
    InitSecBufferDesc(&outbuf_desc, &outbuf, 1);

    sspi_status = s_pSecFn->InitializeSecurityContext(
         &connssl->cred->cred_handle,
         &connssl->ctxt->ctxt_handle,
         host_name,
         connssl->req_flags,
         0,
         0,
         NULL,
         0,
         &connssl->ctxt->ctxt_handle,
         &outbuf_desc,
         &connssl->ret_flags,
         &connssl->ctxt->time_stamp);

#ifdef UNICODE
    Curl_safefree(host_name);
#endif

    if((sspi_status == SEC_E_OK) || (sspi_status == SEC_I_CONTEXT_EXPIRED)) {
      /* send close message which is in output buffer */
      ssize_t written;
      code = Curl_write_plain(conn, conn->sock[sockindex], outbuf.pvBuffer,
                              outbuf.cbBuffer, &written);

      s_pSecFn->FreeContextBuffer(outbuf.pvBuffer);
      if((code != CURLE_OK) || (outbuf.cbBuffer != (size_t)written)) {
        infof(data, "schannel: failed to send close msg: %s"
              " (bytes written: %zd)\n", curl_easy_strerror(code), written);
      }
    }

    /* free SSPI Schannel API security context handle */
    if(connssl->ctxt) {
      s_pSecFn->DeleteSecurityContext(&connssl->ctxt->ctxt_handle);
      Curl_safefree(connssl->ctxt);
    }
  }

  /* free internal buffer for received encrypted data */
  if(connssl->encdata_buffer != NULL) {
    Curl_safefree(connssl->encdata_buffer);
    connssl->encdata_length = 0;
    connssl->encdata_offset = 0;
  }

  /* free internal buffer for received decrypted data */
  if(connssl->decdata_buffer != NULL) {
    Curl_safefree(connssl->decdata_buffer);
    connssl->decdata_length = 0;
    connssl->decdata_offset = 0;
  }

  return CURLE_OK;
}

void Curl_schannel_session_free(void *ptr)
{
  struct curl_schannel_cred *cred = ptr;

  if(cred) {
    s_pSecFn->FreeCredentialsHandle(&cred->cred_handle);
    Curl_safefree(cred);
  }
}

int Curl_schannel_init(void)
{
  return (Curl_sspi_global_init() == CURLE_OK ? 1 : 0);
}

void Curl_schannel_cleanup(void)
{
  Curl_sspi_global_cleanup();
}

size_t Curl_schannel_version(char *buffer, size_t size)
{
  size = snprintf(buffer, size, "SSL-Windows-native");

  return size;
}

#ifdef _WIN32_WCE
static CURLcode verify_certificate(struct connectdata *conn, int sockindex)
{
  SECURITY_STATUS status;
  struct SessionHandle *data = conn->data;
  struct ssl_connect_data *connssl = &conn->ssl[sockindex];
  CURLcode result = CURLE_OK;
  CERT_CONTEXT *pCertContextServer = NULL;
  const CERT_CHAIN_CONTEXT *pChainContext = NULL;

  status = s_pSecFn->QueryContextAttributes(&connssl->ctxt->ctxt_handle,
                                            SECPKG_ATTR_REMOTE_CERT_CONTEXT,
                                            &pCertContextServer);

  if((status != SEC_E_OK) || (pCertContextServer == NULL)) {
    failf(data, "schannel: Failed to read remote certificate context: %s",
          Curl_sspi_strerror(conn, status));
    result = CURLE_PEER_FAILED_VERIFICATION;
  }

  if(result == CURLE_OK) {
    CERT_CHAIN_PARA ChainPara;
    memset(&ChainPara, 0, sizeof(ChainPara));
    ChainPara.cbSize = sizeof(ChainPara);

    if(!CertGetCertificateChain(NULL,
                                pCertContextServer,
                                NULL,
                                pCertContextServer->hCertStore,
                                &ChainPara,
                                0,
                                NULL,
                                &pChainContext)) {
      failf(data, "schannel: CertGetCertificateChain failed: %s",
            Curl_sspi_strerror(conn, GetLastError()));
      pChainContext = NULL;
      result = CURLE_PEER_FAILED_VERIFICATION;
    }

    if(result == CURLE_OK) {
      CERT_SIMPLE_CHAIN *pSimpleChain = pChainContext->rgpChain[0];
      DWORD dwTrustErrorMask = ~(CERT_TRUST_IS_NOT_TIME_NESTED|
                                 CERT_TRUST_REVOCATION_STATUS_UNKNOWN);
      dwTrustErrorMask &= pSimpleChain->TrustStatus.dwErrorStatus;
      if(dwTrustErrorMask) {
        if(dwTrustErrorMask & CERT_TRUST_IS_PARTIAL_CHAIN)
          failf(data, "schannel: CertGetCertificateChain trust error"
                      " CERT_TRUST_IS_PARTIAL_CHAIN");
        if(dwTrustErrorMask & CERT_TRUST_IS_UNTRUSTED_ROOT)
          failf(data, "schannel: CertGetCertificateChain trust error"
                      " CERT_TRUST_IS_UNTRUSTED_ROOT");
        if(dwTrustErrorMask & CERT_TRUST_IS_NOT_TIME_VALID)
          failf(data, "schannel: CertGetCertificateChain trust error"
                      " CERT_TRUST_IS_NOT_TIME_VALID");
        failf(data, "schannel: CertGetCertificateChain error mask: 0x%08x",
              dwTrustErrorMask);
        result = CURLE_PEER_FAILED_VERIFICATION;
      }
    }
  }

  if(result == CURLE_OK) {
    if(data->set.ssl.verifyhost == 1) {
      infof(data, "warning: ignoring unsupported value (1) ssl.verifyhost\n");
    }
    else if(data->set.ssl.verifyhost == 2) {
      WCHAR cert_hostname[128];
      WCHAR *hostname = Curl_convert_UTF8_to_wchar(conn->host.name);
      DWORD len;

      len = CertGetNameStringW(pCertContextServer,
                               CERT_NAME_DNS_TYPE,
                               0,
                               NULL,
                               cert_hostname,
                               128);
      if(len > 0 && cert_hostname[0] == '*') {
        /* this is a wildcard cert.  try matching the last len - 1 chars */
        int hostname_len = strlen(conn->host.name);
        if(wcsicmp(cert_hostname + 1, hostname + hostname_len - len + 2) != 0)
          result = CURLE_PEER_FAILED_VERIFICATION;
      }
      else if(len == 0 || wcsicmp(hostname, cert_hostname) != 0) {
        result = CURLE_PEER_FAILED_VERIFICATION;
      }
      if(result == CURLE_PEER_FAILED_VERIFICATION) {
        const char *_cert_hostname;
        _cert_hostname = Curl_convert_wchar_to_UTF8(cert_hostname);
        failf(data, "schannel: CertGetNameString() certificate hostname "
              "(%s) did not match connection (%s)",
              _cert_hostname, conn->host.name);
        Curl_safefree((void *)_cert_hostname);
      }
      Curl_safefree(hostname);
    }
  }

  if(pChainContext)
    CertFreeCertificateChain(pChainContext);

  if(pCertContextServer)
    CertFreeCertificateContext(pCertContextServer);

  return result;
}
#endif /* _WIN32_WCE */

#endif /* USE_SCHANNEL */