/* engine-uiserver.c - Uiserver engine.

 * Copyright (C) 2000 Werner Koch (dd9jn)

 * Copyright (C) 2001, 2002, 2003, 2004, 2005, 2007, 2009 g10 Code GmbH

 *

 * This file is part of GPGME.

 *

 * GPGME is free software; you can redistribute it and/or modify it

 * under the terms of the GNU Lesser General Public License as

 * published by the Free Software Foundation; either version 2.1 of

 * the License, or (at your option) any later version.

 *

 * GPGME is distributed in the hope that it will be useful, but

 * WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

 * Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public

 * License along with this program; if not, see <https://gnu.org/licenses/>.

 * SPDX-License-Identifier: LGPL-2.1-or-later

 */

/* Peculiar: Use special keys from email address for recipient and

   signer (==sender).  Use no data objects with encryption for

   prep_encrypt.  */

#if HAVE_CONFIG_H

#include <config.h>

#endif

#include <stdlib.h>

#include <string.h>

#ifdef HAVE_SYS_TYPES_H

# include <sys/types.h>

#endif

#include <assert.h>

#ifdef HAVE_UNISTD_H

# include <unistd.h>

#endif

#include <locale.h>

#include <fcntl.h> /* FIXME */

#include <errno.h>

#include "gpgme.h"

#include "util.h"

#include "ops.h"

#include "wait.h"

#include "priv-io.h"

#include "sema.h"

#include "data.h"

#include "assuan.h"

#include "debug.h"

#include "engine-backend.h"

typedef struct

{

  int fd;	/* FD we talk about.  */

  int server_fd;/* Server FD for this connection.  */

  int dir;	/* Inbound/Outbound, maybe given implicit?  */

  void *data;	/* Handler-specific data.  */

  void *tag;	/* ID from the user for gpgme_remove_io_callback.  */

  char server_fd_str[15]; /* Same as SERVER_FD but as a string.  We

                             need this because _gpgme_io_fd2str can't

                             be used on a closed descriptor.  */

} iocb_data_t;

struct engine_uiserver

{

  assuan_context_t assuan_ctx;

  int lc_ctype_set;

  int lc_messages_set;

  gpgme_protocol_t protocol;

  iocb_data_t status_cb;

  /* Input, output etc are from the servers perspective.  */

  iocb_data_t input_cb;

  gpgme_data_t input_helper_data;  /* Input helper data object.  */

  void *input_helper_memory;       /* Input helper memory block.  */

  iocb_data_t output_cb;

  iocb_data_t message_cb;

  struct

  {

    engine_status_handler_t fnc;

    void *fnc_value;

    gpgme_status_cb_t mon_cb;

    void *mon_cb_value;

  } status;

  struct

  {

    engine_colon_line_handler_t fnc;

    void *fnc_value;

    struct

    {

      char *line;

      int linesize;

      int linelen;

    } attic;

    int any; /* any data line seen */

  } colon;

  gpgme_data_t inline_data;  /* Used to collect D lines.  */

  struct gpgme_io_cbs io_cbs;

};

typedef struct engine_uiserver *engine_uiserver_t;

static void uiserver_io_event (void *engine,

                            gpgme_event_io_t type, void *type_data);

static char *

uiserver_get_version (const char *file_name)

{

  (void)file_name;

  return NULL;

}

static const char *

uiserver_get_req_version (void)

{

  return NULL;

}

static void

close_notify_handler (int fd, void *opaque)

{

  engine_uiserver_t uiserver = opaque;

  assert (fd != -1);

  if (uiserver->status_cb.fd == fd)

    {

      if (uiserver->status_cb.tag)

	(*uiserver->io_cbs.remove) (uiserver->status_cb.tag);

      uiserver->status_cb.fd = -1;

      uiserver->status_cb.tag = NULL;

    }

  else if (uiserver->input_cb.fd == fd)

    {

      if (uiserver->input_cb.tag)

	(*uiserver->io_cbs.remove) (uiserver->input_cb.tag);

      uiserver->input_cb.fd = -1;

      uiserver->input_cb.tag = NULL;

      if (uiserver->input_helper_data)

        {

          gpgme_data_release (uiserver->input_helper_data);

          uiserver->input_helper_data = NULL;

        }

      if (uiserver->input_helper_memory)

        {

          free (uiserver->input_helper_memory);

          uiserver->input_helper_memory = NULL;

        }

    }

  else if (uiserver->output_cb.fd == fd)

    {

      if (uiserver->output_cb.tag)

	(*uiserver->io_cbs.remove) (uiserver->output_cb.tag);

      uiserver->output_cb.fd = -1;

      uiserver->output_cb.tag = NULL;

    }

  else if (uiserver->message_cb.fd == fd)

    {

      if (uiserver->message_cb.tag)

	(*uiserver->io_cbs.remove) (uiserver->message_cb.tag);

      uiserver->message_cb.fd = -1;

      uiserver->message_cb.tag = NULL;

    }

}

/* This is the default inquiry callback.  We use it to handle the

   Pinentry notifications.  */

static gpgme_error_t

default_inq_cb (engine_uiserver_t uiserver, const char *line)

{

  (void)uiserver;

  if (!strncmp (line, "PINENTRY_LAUNCHED", 17) && (line[17]==' '||!line[17]))

    {

      _gpgme_allow_set_foreground_window ((pid_t)strtoul (line+17, NULL, 10));

    }

  return 0;

}

static gpgme_error_t

uiserver_cancel (void *engine)

{

  engine_uiserver_t uiserver = engine;

  if (!uiserver)

    return gpg_error (GPG_ERR_INV_VALUE);

  if (uiserver->status_cb.fd != -1)

    _gpgme_io_close (uiserver->status_cb.fd);

  if (uiserver->input_cb.fd != -1)

    _gpgme_io_close (uiserver->input_cb.fd);

  if (uiserver->output_cb.fd != -1)

    _gpgme_io_close (uiserver->output_cb.fd);

  if (uiserver->message_cb.fd != -1)

    _gpgme_io_close (uiserver->message_cb.fd);

  if (uiserver->assuan_ctx)

    {

      assuan_release (uiserver->assuan_ctx);

      uiserver->assuan_ctx = NULL;

    }

  return 0;

}

static void

uiserver_release (void *engine)

{

  engine_uiserver_t uiserver = engine;

  if (!uiserver)

    return;

  uiserver_cancel (engine);

  free (uiserver->colon.attic.line);

  free (uiserver);

}

static gpgme_error_t

uiserver_new (void **engine, const char *file_name, const char *home_dir,

              const char *version)

{

  gpgme_error_t err = 0;

  engine_uiserver_t uiserver;

  char *dft_display = NULL;

  char dft_ttyname[64];

  char *env_tty = NULL;

  char *dft_ttytype = NULL;

  char *optstr;

  (void)home_dir;

  (void)version; /* Not yet used.  */

  uiserver = calloc (1, sizeof *uiserver);

  if (!uiserver)

    return gpg_error_from_syserror ();

  uiserver->protocol = GPGME_PROTOCOL_DEFAULT;

  uiserver->status_cb.fd = -1;

  uiserver->status_cb.dir = 1;

  uiserver->status_cb.tag = 0;

  uiserver->status_cb.data = uiserver;

  uiserver->input_cb.fd = -1;

  uiserver->input_cb.dir = 0;

  uiserver->input_cb.tag = 0;

  uiserver->input_cb.server_fd = -1;

  *uiserver->input_cb.server_fd_str = 0;

  uiserver->output_cb.fd = -1;

  uiserver->output_cb.dir = 1;

  uiserver->output_cb.tag = 0;

  uiserver->output_cb.server_fd = -1;

  *uiserver->output_cb.server_fd_str = 0;

  uiserver->message_cb.fd = -1;

  uiserver->message_cb.dir = 0;

  uiserver->message_cb.tag = 0;

  uiserver->message_cb.server_fd = -1;

  *uiserver->message_cb.server_fd_str = 0;

  uiserver->status.fnc = 0;

  uiserver->colon.fnc = 0;

  uiserver->colon.attic.line = 0;

  uiserver->colon.attic.linesize = 0;

  uiserver->colon.attic.linelen = 0;

  uiserver->colon.any = 0;

  uiserver->inline_data = NULL;

  uiserver->io_cbs.add = NULL;

  uiserver->io_cbs.add_priv = NULL;

  uiserver->io_cbs.remove = NULL;

  uiserver->io_cbs.event = NULL;

  uiserver->io_cbs.event_priv = NULL;

  err = assuan_new_ext (&uiserver->assuan_ctx, GPG_ERR_SOURCE_GPGME,

			&_gpgme_assuan_malloc_hooks, _gpgme_assuan_log_cb,

			NULL);

  if (err)

    goto leave;

  assuan_ctx_set_system_hooks (uiserver->assuan_ctx,

			       &_gpgme_assuan_system_hooks);

  err = assuan_socket_connect (uiserver->assuan_ctx,

			       file_name ?

			       file_name : _gpgme_get_default_uisrv_socket (),

			       0, ASSUAN_SOCKET_SERVER_FDPASSING);

  if (err)

    goto leave;

  err = _gpgme_getenv ("DISPLAY", &dft_display);

  if (err)

    goto leave;

  if (dft_display)

    {

      if (gpgrt_asprintf (&optstr, "OPTION display=%s", dft_display) < 0)

        {

	  err = gpg_error_from_syserror ();

	  free (dft_display);

	  goto leave;

	}

      free (dft_display);

      err = assuan_transact (uiserver->assuan_ctx, optstr, NULL, NULL, NULL,

			     NULL, NULL, NULL);

      gpgrt_free (optstr);

      if (err)

	goto leave;

    }

  err = _gpgme_getenv ("GPG_TTY", &env_tty);

  if (isatty (1) || env_tty || err)

    {

      int rc = 0;

      if (err)

        goto leave;

      else if (env_tty)

        {

          snprintf (dft_ttyname, sizeof (dft_ttyname), "%s", env_tty);

          free (env_tty);

        }

      else

        rc = ttyname_r (1, dft_ttyname, sizeof (dft_ttyname));

      /* Even though isatty() returns 1, ttyname_r() may fail in many

	 ways, e.g., when /dev/pts is not accessible under chroot.  */

      if (!rc)

	{

	  if (gpgrt_asprintf (&optstr, "OPTION ttyname=%s", dft_ttyname) < 0)

	    {

	      err = gpg_error_from_syserror ();

	      goto leave;

	    }

	  err = assuan_transact (uiserver->assuan_ctx, optstr, NULL, NULL, NULL,

				 NULL, NULL, NULL);

	  gpgrt_free (optstr);

	  if (err)

	    goto leave;

	  err = _gpgme_getenv ("TERM", &dft_ttytype);

	  if (err)

	    goto leave;

	  if (dft_ttytype)

	    {

	      if (gpgrt_asprintf (&optstr, "OPTION ttytype=%s", dft_ttytype)< 0)

		{

		  err = gpg_error_from_syserror ();

		  free (dft_ttytype);

		  goto leave;

		}

	      free (dft_ttytype);

	      err = assuan_transact (uiserver->assuan_ctx, optstr, NULL, NULL,

				     NULL, NULL, NULL, NULL);

	      gpgrt_free (optstr);

	      if (err)

		goto leave;

	    }

	}

    }

#ifdef HAVE_W32_SYSTEM

  /* Under Windows we need to use AllowSetForegroundWindow.  Tell

     uiserver to tell us when it needs it.  */

  if (!err)

    {

      err = assuan_transact (uiserver->assuan_ctx, "OPTION allow-pinentry-notify",

                             NULL, NULL, NULL, NULL, NULL, NULL);

      if (gpg_err_code (err) == GPG_ERR_UNKNOWN_OPTION)

        err = 0; /* This is a new feature of uiserver.  */

    }

#endif /*HAVE_W32_SYSTEM*/

 leave:

  if (err)

    uiserver_release (uiserver);

  else

    *engine = uiserver;

  return err;

}

static gpgme_error_t

uiserver_set_locale (void *engine, int category, const char *value)

{

  engine_uiserver_t uiserver = engine;

  gpgme_error_t err;

  char *optstr;

  const char *catstr;

  /* FIXME: If value is NULL, we need to reset the option to default.

     But we can't do this.  So we error out here.  UISERVER needs support

     for this.  */

  if (category == LC_CTYPE)

    {

      catstr = "lc-ctype";

      if (!value && uiserver->lc_ctype_set)

	return gpg_error (GPG_ERR_INV_VALUE);

      if (value)

	uiserver->lc_ctype_set = 1;

    }

#ifdef LC_MESSAGES

  else if (category == LC_MESSAGES)

    {

      catstr = "lc-messages";

      if (!value && uiserver->lc_messages_set)

	return gpg_error (GPG_ERR_INV_VALUE);

      if (value)

	uiserver->lc_messages_set = 1;

    }

#endif /* LC_MESSAGES */

  else

    return gpg_error (GPG_ERR_INV_VALUE);

  /* FIXME: Reset value to default.  */

  if (!value)

    return 0;

  if (gpgrt_asprintf (&optstr, "OPTION %s=%s", catstr, value) < 0)

    err = gpg_error_from_syserror ();

  else

    {

      err = assuan_transact (uiserver->assuan_ctx, optstr, NULL, NULL,

			     NULL, NULL, NULL, NULL);

      gpgrt_free (optstr);

    }

  return err;

}

static gpgme_error_t

uiserver_set_protocol (void *engine, gpgme_protocol_t protocol)

{

  engine_uiserver_t uiserver = engine;

  if (protocol != GPGME_PROTOCOL_OpenPGP

      && protocol != GPGME_PROTOCOL_CMS

      && protocol != GPGME_PROTOCOL_DEFAULT)

    return gpg_error (GPG_ERR_INV_VALUE);

  uiserver->protocol = protocol;

  return 0;

}

static gpgme_error_t

uiserver_assuan_simple_command (engine_uiserver_t uiserver, const char *cmd,

                                engine_status_handler_t status_fnc,

                                void *status_fnc_value)

{

  assuan_context_t ctx = uiserver->assuan_ctx;

  gpg_error_t err;

  char *line;

  size_t linelen;

  err = assuan_write_line (ctx, cmd);

  if (err)

    return err;

  do

    {

      err = assuan_read_line (ctx, &line, &linelen);

      if (err)

	return err;

      if (*line == '#' || !linelen)

	continue;

      if (linelen >= 2

	  && line[0] == 'O' && line[1] == 'K'

	  && (line[2] == '\0' || line[2] == ' '))

	return 0;

      else if (linelen >= 4

	  && line[0] == 'E' && line[1] == 'R' && line[2] == 'R'

	  && line[3] == ' ')

	err = atoi (&line[4]);

      else if (linelen >= 2

	       && line[0] == 'S' && line[1] == ' ')

	{

	  char *rest;

	  gpgme_status_code_t r;

	  rest = strchr (line + 2, ' ');

	  if (!rest)

	    rest = line + linelen; /* set to an empty string */

	  else

	    *(rest++) = 0;

	  r = _gpgme_parse_status (line + 2);

          if (uiserver->status.mon_cb && r != GPGME_STATUS_PROGRESS)

            {

              /* Note that we call the monitor even if we do

               * not know the status code (r < 0).  */

              err = uiserver->status.mon_cb (uiserver->status.mon_cb_value,

                                             line + 2, rest);

            }

          if (err)

            ;

	  else if (r >= 0 && status_fnc)

	    err = status_fnc (status_fnc_value, r, rest);

	  else

	    err = gpg_error (GPG_ERR_GENERAL);

	}

      else

	err = gpg_error (GPG_ERR_GENERAL);

    }

  while (!err);

  return err;

}

typedef enum { INPUT_FD, OUTPUT_FD, MESSAGE_FD } fd_type_t;

#define COMMANDLINELEN 40

static gpgme_error_t

uiserver_set_fd (engine_uiserver_t uiserver, fd_type_t fd_type, const char *opt)

{

  gpg_error_t err = 0;

  char line[COMMANDLINELEN];

  const char *which;

  iocb_data_t *iocb_data;

  int dir;

  switch (fd_type)

    {

    case INPUT_FD:

      which = "INPUT";

      iocb_data = &uiserver->input_cb;

      break;

    case OUTPUT_FD:

      which = "OUTPUT";

      iocb_data = &uiserver->output_cb;

      break;

    case MESSAGE_FD:

      which = "MESSAGE";

      iocb_data = &uiserver->message_cb;

      break;

    default:

      return gpg_error (GPG_ERR_INV_VALUE);

    }

  dir = iocb_data->dir;

  /* We try to short-cut the communication by giving UISERVER direct

     access to the file descriptor, rather than using a pipe.  */

  iocb_data->server_fd = _gpgme_data_get_fd (iocb_data->data);

  if (iocb_data->server_fd < 0)

    {

      int fds[2];

      if (_gpgme_io_pipe (fds, 0) < 0)

	return gpg_error_from_syserror ();

      iocb_data->fd = dir ? fds[0] : fds[1];

      iocb_data->server_fd = dir ? fds[1] : fds[0];

      if (_gpgme_io_set_close_notify (iocb_data->fd,

				      close_notify_handler, uiserver))

	{

	  err = gpg_error (GPG_ERR_GENERAL);

	  goto leave_set_fd;

	}

    }

  err = assuan_sendfd (uiserver->assuan_ctx, iocb_data->server_fd);

  if (err)

    goto leave_set_fd;

  _gpgme_io_close (iocb_data->server_fd);

  iocb_data->server_fd = -1;

  if (opt)

    snprintf (line, COMMANDLINELEN, "%s FD %s", which, opt);

  else

    snprintf (line, COMMANDLINELEN, "%s FD", which);

  err = uiserver_assuan_simple_command (uiserver, line, NULL, NULL);

 leave_set_fd:

  if (err)

    {

      _gpgme_io_close (iocb_data->fd);

      iocb_data->fd = -1;

      if (iocb_data->server_fd != -1)

        {

          _gpgme_io_close (iocb_data->server_fd);

          iocb_data->server_fd = -1;

        }

    }

  return err;

}

static const char *

map_data_enc (gpgme_data_t d)

{

  switch (gpgme_data_get_encoding (d))

    {

    case GPGME_DATA_ENCODING_NONE:

      break;

    case GPGME_DATA_ENCODING_BINARY:

      return "--binary";

    case GPGME_DATA_ENCODING_BASE64:

      return "--base64";

    case GPGME_DATA_ENCODING_ARMOR:

      return "--armor";

    default:

      break;

    }

  return NULL;

}

static gpgme_error_t

status_handler (void *opaque, int fd)

{

  struct io_cb_data *data = (struct io_cb_data *) opaque;

  engine_uiserver_t uiserver = (engine_uiserver_t) data->handler_value;

  gpgme_error_t err = 0;

  char *line;

  size_t linelen;

  do

    {

      err = assuan_read_line (uiserver->assuan_ctx, &line, &linelen);

      if (err)

	{

	  /* Try our best to terminate the connection friendly.  */

	  /*	  assuan_write_line (uiserver->assuan_ctx, "BYE"); */

          TRACE (DEBUG_CTX, "gpgme:status_handler", uiserver,

		  "fd 0x%x: error from assuan (%d) getting status line : %s",

                  fd, err, gpg_strerror (err));

	}

      else if (linelen >= 3

	       && line[0] == 'E' && line[1] == 'R' && line[2] == 'R'

	       && (line[3] == '\0' || line[3] == ' '))

	{

	  if (line[3] == ' ')

	    err = atoi (&line[4]);

	  if (! err)

	    err = gpg_error (GPG_ERR_GENERAL);

          TRACE (DEBUG_CTX, "gpgme:status_handler", uiserver,

		  "fd 0x%x: ERR line - mapped to: %s",

                  fd, err ? gpg_strerror (err) : "ok");

	  /* Try our best to terminate the connection friendly.  */

	  /*	  assuan_write_line (uiserver->assuan_ctx, "BYE"); */

	}

      else if (linelen >= 2

	       && line[0] == 'O' && line[1] == 'K'

	       && (line[2] == '\0' || line[2] == ' '))

	{

	  if (uiserver->status.fnc)

            {

              char emptystring[1] = {0};

              err = uiserver->status.fnc (uiserver->status.fnc_value,

                                          GPGME_STATUS_EOF, emptystring);

              if (gpg_err_code (err) == GPG_ERR_FALSE)

                err = 0; /* Drop special error code.  */

            }

	  if (!err && uiserver->colon.fnc && uiserver->colon.any)

            {

              /* We must tell a colon function about the EOF. We do

                 this only when we have seen any data lines.  Note

                 that this inlined use of colon data lines will

                 eventually be changed into using a regular data

                 channel. */

              uiserver->colon.any = 0;

              err = uiserver->colon.fnc (uiserver->colon.fnc_value, NULL);

            }

          TRACE (DEBUG_CTX, "gpgme:status_handler", uiserver,

		  "fd 0x%x: OK line - final status: %s",

                  fd, err ? gpg_strerror (err) : "ok");

	  _gpgme_io_close (uiserver->status_cb.fd);

	  return err;

	}

      else if (linelen > 2

	       && line[0] == 'D' && line[1] == ' '

	       && uiserver->colon.fnc)

        {

	  /* We are using the colon handler even for plain inline data

             - strange name for that function but for historic reasons

             we keep it.  */

          /* FIXME We can't use this for binary data because we

             assume this is a string.  For the current usage of colon

             output it is correct.  */

          char *src = line + 2;

	  char *end = line + linelen;

	  char *dst;

          char **aline = &uiserver->colon.attic.line;

	  int *alinelen = &uiserver->colon.attic.linelen;

	  if (uiserver->colon.attic.linesize < *alinelen + linelen + 1)

	    {

	      char *newline = realloc (*aline, *alinelen + linelen + 1);

	      if (!newline)

		err = gpg_error_from_syserror ();

	      else

		{

		  *aline = newline;

		  uiserver->colon.attic.linesize = *alinelen + linelen + 1;

		}

	    }

	  if (!err)

	    {

	      dst = *aline + *alinelen;

	      while (!err && src < end)

		{

		  if (*src == '%' && src + 2 < end)

		    {

		      /* Handle escaped characters.  */

		      ++src;

		      *dst = _gpgme_hextobyte (src);

		      (*alinelen)++;

		      src += 2;

		    }

		  else

		    {

		      *dst = *src++;

		      (*alinelen)++;

		    }

		  if (*dst == '\n')

		    {

		      /* Terminate the pending line, pass it to the colon

			 handler and reset it.  */

		      uiserver->colon.any = 1;

		      if (*alinelen > 1 && *(dst - 1) == '\r')

			dst--;

		      *dst = '\0';

		      /* FIXME How should we handle the return code?  */

		      err = uiserver->colon.fnc (uiserver->colon.fnc_value, *aline);

		      if (!err)

			{

			  dst = *aline;

			  *alinelen = 0;

			}

		    }

		  else

		    dst++;

		}

	    }

          TRACE (DEBUG_CTX, "gpgme:status_handler", uiserver,

		  "fd 0x%x: D line; final status: %s",

                  fd, err? gpg_strerror (err):"ok");

        }

      else if (linelen > 2

	       && line[0] == 'D' && line[1] == ' '

	       && uiserver->inline_data)

        {

          char *src = line + 2;

	  char *end = line + linelen;

	  char *dst = src;

          gpgme_ssize_t nwritten;

          linelen = 0;

          while (src < end)

            {

              if (*src == '%' && src + 2 < end)

                {

                  /* Handle escaped characters.  */

                  ++src;

                  *dst++ = _gpgme_hextobyte (src);

                  src += 2;

                }

              else

                *dst++ = *src++;

              linelen++;

            }

          src = line + 2;

          while (linelen > 0)

            {

              nwritten = gpgme_data_write (uiserver->inline_data, src, linelen);

              if (!nwritten || (nwritten < 0 && errno != EINTR)

                  || nwritten > linelen)

                {

                  err = gpg_error_from_syserror ();

                  break;

                }

              src += nwritten;

              linelen -= nwritten;

            }

          TRACE (DEBUG_CTX, "gpgme:status_handler", uiserver,

		  "fd 0x%x: D inlinedata; final status: %s",

                  fd, err? gpg_strerror (err):"ok");

        }

      else if (linelen > 2

	       && line[0] == 'S' && line[1] == ' ')

	{

	  char *rest;

	  gpgme_status_code_t r;

	  rest = strchr (line + 2, ' ');

	  if (!rest)

	    rest = line + linelen; /* set to an empty string */

	  else

	    *(rest++) = 0;

	  r = _gpgme_parse_status (line + 2);

	  if (r >= 0)

	    {

	      if (uiserver->status.fnc)

                {

                  err = uiserver->status.fnc (uiserver->status.fnc_value,

                                              r, rest);

                  if (gpg_err_code (err) == GPG_ERR_FALSE)

                    err = 0; /* Drop special error code.  */

                }

	    }

	  else

	    fprintf (stderr, "[UNKNOWN STATUS]%s %s", line + 2, rest);

          TRACE (DEBUG_CTX, "gpgme:status_handler", uiserver,

		  "fd 0x%x: S line (%s) - final status: %s",

                  fd, line+2, err? gpg_strerror (err):"ok");

	}

      else if (linelen >= 7

               && line[0] == 'I' && line[1] == 'N' && line[2] == 'Q'

               && line[3] == 'U' && line[4] == 'I' && line[5] == 'R'

               && line[6] == 'E'

               && (line[7] == '\0' || line[7] == ' '))

        {

          char *keyword = line+7;

          while (*keyword == ' ')

            keyword++;;

          default_inq_cb (uiserver, keyword);

          assuan_write_line (uiserver->assuan_ctx, "END");

        }

    }

  while (!err && assuan_pending_line (uiserver->assuan_ctx));

  return err;

}

static gpgme_error_t

add_io_cb (engine_uiserver_t uiserver, iocb_data_t *iocbd, gpgme_io_cb_t handler)

{

  gpgme_error_t err;