/* GDBus - GLib D-Bus Library

 *

 * Copyright (C) 2008-2010 Red Hat, Inc.

 *

 * This library 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.

 *

 * This library 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 library; if not, see <http://www.gnu.org/licenses/>.

 *

 * Author: David Zeuthen <davidz@redhat.com>

 */

#include "config.h"

#include <stdlib.h>

#include <string.h>

#include <gobject/gvaluecollector.h>

#include "gcredentials.h"

#include "gcredentialsprivate.h"

#include "gnetworking.h"

#include "gioerror.h"

#include "gioenumtypes.h"

#include "glibintl.h"

/**

 * SECTION:gcredentials

 * @short_description: An object containing credentials

 * @include: gio/gio.h

 *

 * The #GCredentials type is a reference-counted wrapper for native

 * credentials. This information is typically used for identifying,

 * authenticating and authorizing other processes.

 *

 * Some operating systems supports looking up the credentials of the

 * remote peer of a communication endpoint - see e.g.

 * g_socket_get_credentials().

 *

 * Some operating systems supports securely sending and receiving

 * credentials over a Unix Domain Socket, see

 * #GUnixCredentialsMessage, g_unix_connection_send_credentials() and

 * g_unix_connection_receive_credentials() for details.

 *

 * On Linux, the native credential type is a `struct ucred` - see the

 * unix(7) man page for details. This corresponds to

 * %G_CREDENTIALS_TYPE_LINUX_UCRED.

 *

 * On Apple operating systems (including iOS, tvOS, and macOS),

 * the native credential type is a `struct xucred`.

 * This corresponds to %G_CREDENTIALS_TYPE_APPLE_XUCRED.

 *

 * On FreeBSD, Debian GNU/kFreeBSD, and GNU/Hurd, the native

 * credential type is a `struct cmsgcred`. This corresponds

 * to %G_CREDENTIALS_TYPE_FREEBSD_CMSGCRED.

 *

 * On NetBSD, the native credential type is a `struct unpcbid`.

 * This corresponds to %G_CREDENTIALS_TYPE_NETBSD_UNPCBID.

 *

 * On OpenBSD, the native credential type is a `struct sockpeercred`.

 * This corresponds to %G_CREDENTIALS_TYPE_OPENBSD_SOCKPEERCRED.

 *

 * On Solaris (including OpenSolaris and its derivatives), the native

 * credential type is a `ucred_t`. This corresponds to

 * %G_CREDENTIALS_TYPE_SOLARIS_UCRED.

 */

/**

 * GCredentials:

 *

 * The #GCredentials structure contains only private data and

 * should only be accessed using the provided API.

 *

 * Since: 2.26

 */

struct _GCredentials

{

  /*< private >*/

  GObject parent_instance;

#if G_CREDENTIALS_USE_LINUX_UCRED

  struct ucred native;

#elif G_CREDENTIALS_USE_APPLE_XUCRED

  struct xucred native;

#elif G_CREDENTIALS_USE_FREEBSD_CMSGCRED

  struct cmsgcred native;

#elif G_CREDENTIALS_USE_NETBSD_UNPCBID

  struct unpcbid native;

#elif G_CREDENTIALS_USE_OPENBSD_SOCKPEERCRED

  struct sockpeercred native;

#elif G_CREDENTIALS_USE_SOLARIS_UCRED

  ucred_t *native;

#else

  #ifdef __GNUC__

  #pragma GCC diagnostic push

  #pragma GCC diagnostic warning "-Wcpp"

  #warning Please add GCredentials support for your OS

  #pragma GCC diagnostic pop

  #endif

#endif

};

/**

 * GCredentialsClass:

 *

 * Class structure for #GCredentials.

 *

 * Since: 2.26

 */

struct _GCredentialsClass

{

  /*< private >*/

  GObjectClass parent_class;

};

G_DEFINE_TYPE (GCredentials, g_credentials, G_TYPE_OBJECT)

static void

g_credentials_finalize (GObject *object)

{

#if G_CREDENTIALS_USE_SOLARIS_UCRED

  GCredentials *credentials = G_CREDENTIALS (object);

  ucred_free (credentials->native);

#endif

  if (G_OBJECT_CLASS (g_credentials_parent_class)->finalize != NULL)

    G_OBJECT_CLASS (g_credentials_parent_class)->finalize (object);

}

static void

g_credentials_class_init (GCredentialsClass *klass)

{

  GObjectClass *gobject_class;

  gobject_class = G_OBJECT_CLASS (klass);

  gobject_class->finalize = g_credentials_finalize;

}

static void

g_credentials_init (GCredentials *credentials)

{

#if G_CREDENTIALS_USE_LINUX_UCRED

  credentials->native.pid = getpid ();

  credentials->native.uid = geteuid ();

  credentials->native.gid = getegid ();

#elif G_CREDENTIALS_USE_APPLE_XUCRED

  gsize i;

  credentials->native.cr_version = XUCRED_VERSION;

  credentials->native.cr_uid = geteuid ();

  credentials->native.cr_ngroups = 1;

  credentials->native.cr_groups[0] = getegid ();

  /* FIXME: In principle this could use getgroups() to fill in the rest

   * of cr_groups, but then we'd have to handle the case where a process

   * can have more than NGROUPS groups, if that's even possible. A macOS

   * user would have to develop and test this.

   *

   * For now we fill it with -1 (meaning "no data"). */

  for (i = 1; i < NGROUPS; i++)

    credentials->native.cr_groups[i] = -1;

#elif G_CREDENTIALS_USE_FREEBSD_CMSGCRED

  memset (&credentials->native, 0, sizeof (struct cmsgcred));

  credentials->native.cmcred_pid  = getpid ();

  credentials->native.cmcred_euid = geteuid ();

  credentials->native.cmcred_gid  = getegid ();

#elif G_CREDENTIALS_USE_NETBSD_UNPCBID

  credentials->native.unp_pid = getpid ();

  credentials->native.unp_euid = geteuid ();

  credentials->native.unp_egid = getegid ();

#elif G_CREDENTIALS_USE_OPENBSD_SOCKPEERCRED

  credentials->native.pid = getpid ();

  credentials->native.uid = geteuid ();

  credentials->native.gid = getegid ();

#elif G_CREDENTIALS_USE_SOLARIS_UCRED

  credentials->native = ucred_get (P_MYID);

#endif

}

/* ---------------------------------------------------------------------------------------------------- */

/**

 * g_credentials_new:

 *

 * Creates a new #GCredentials object with credentials matching the

 * the current process.

 *

 * Returns: (transfer full): A #GCredentials. Free with g_object_unref().

 *

 * Since: 2.26

 */

GCredentials *

g_credentials_new (void)

{

  return g_object_new (G_TYPE_CREDENTIALS, NULL);

}

/* ---------------------------------------------------------------------------------------------------- */

/**

 * g_credentials_to_string:

 * @credentials: A #GCredentials object.

 *

 * Creates a human-readable textual representation of @credentials

 * that can be used in logging and debug messages. The format of the

 * returned string may change in future GLib release.

 *

 * Returns: (transfer full): A string that should be freed with g_free().

 *

 * Since: 2.26

 */

gchar *

g_credentials_to_string (GCredentials *credentials)

{

  GString *ret;

#if G_CREDENTIALS_USE_APPLE_XUCRED

  glib_typeof (credentials->native.cr_ngroups) i;

#endif

  g_return_val_if_fail (G_IS_CREDENTIALS (credentials), NULL);

  ret = g_string_new ("GCredentials:");

#if G_CREDENTIALS_USE_LINUX_UCRED

  g_string_append (ret, "linux-ucred:");

  if (credentials->native.pid != (pid_t) -1)

    g_string_append_printf (ret, "pid=%" G_GINT64_FORMAT ",", (gint64) credentials->native.pid);

  if (credentials->native.uid != (uid_t) -1)

    g_string_append_printf (ret, "uid=%" G_GINT64_FORMAT ",", (gint64) credentials->native.uid);

  if (credentials->native.gid != (gid_t) -1)

    g_string_append_printf (ret, "gid=%" G_GINT64_FORMAT ",", (gint64) credentials->native.gid);

  if (ret->str[ret->len - 1] == ',')

    ret->str[ret->len - 1] = '\0';

#elif G_CREDENTIALS_USE_APPLE_XUCRED

  g_string_append (ret, "apple-xucred:");

  g_string_append_printf (ret, "version=%u,", credentials->native.cr_version);

  if (credentials->native.cr_uid != (uid_t) -1)

    g_string_append_printf (ret, "uid=%" G_GINT64_FORMAT ",", (gint64) credentials->native.cr_uid);

  for (i = 0; i < credentials->native.cr_ngroups; i++)

    g_string_append_printf (ret, "gid=%" G_GINT64_FORMAT ",", (gint64) credentials->native.cr_groups[i]);

  if (ret->str[ret->len - 1] == ',')

    ret->str[ret->len - 1] = '\0';

#elif G_CREDENTIALS_USE_FREEBSD_CMSGCRED

  g_string_append (ret, "freebsd-cmsgcred:");

  if (credentials->native.cmcred_pid != (pid_t) -1)

    g_string_append_printf (ret, "pid=%" G_GINT64_FORMAT ",", (gint64) credentials->native.cmcred_pid);

  if (credentials->native.cmcred_euid != (uid_t) -1)

    g_string_append_printf (ret, "uid=%" G_GINT64_FORMAT ",", (gint64) credentials->native.cmcred_euid);

  if (credentials->native.cmcred_gid != (gid_t) -1)

    g_string_append_printf (ret, "gid=%" G_GINT64_FORMAT ",", (gint64) credentials->native.cmcred_gid);

#elif G_CREDENTIALS_USE_NETBSD_UNPCBID

  g_string_append (ret, "netbsd-unpcbid:");

  if (credentials->native.unp_pid != (pid_t) -1)

    g_string_append_printf (ret, "pid=%" G_GINT64_FORMAT ",", (gint64) credentials->native.unp_pid);

  if (credentials->native.unp_euid != (uid_t) -1)

    g_string_append_printf (ret, "uid=%" G_GINT64_FORMAT ",", (gint64) credentials->native.unp_euid);

  if (credentials->native.unp_egid != (gid_t) -1)

    g_string_append_printf (ret, "gid=%" G_GINT64_FORMAT ",", (gint64) credentials->native.unp_egid);

  ret->str[ret->len - 1] = '\0';

#elif G_CREDENTIALS_USE_OPENBSD_SOCKPEERCRED

  g_string_append (ret, "openbsd-sockpeercred:");

  if (credentials->native.pid != (pid_t) -1)

    g_string_append_printf (ret, "pid=%" G_GINT64_FORMAT ",", (gint64) credentials->native.pid);

  if (credentials->native.uid != (uid_t) -1)

    g_string_append_printf (ret, "uid=%" G_GINT64_FORMAT ",", (gint64) credentials->native.uid);

  if (credentials->native.gid != (gid_t) -1)

    g_string_append_printf (ret, "gid=%" G_GINT64_FORMAT ",", (gint64) credentials->native.gid);

  if (ret->str[ret->len - 1] == ',')

    ret->str[ret->len - 1] = '\0';

#elif G_CREDENTIALS_USE_SOLARIS_UCRED

  g_string_append (ret, "solaris-ucred:");

  {

    id_t id;

    if ((id = ucred_getpid (credentials->native)) != (id_t) -1)

      g_string_append_printf (ret, "pid=%" G_GINT64_FORMAT ",", (gint64) id);

    if ((id = ucred_geteuid (credentials->native)) != (id_t) -1)

      g_string_append_printf (ret, "uid=%" G_GINT64_FORMAT ",", (gint64) id);

    if ((id = ucred_getegid (credentials->native)) != (id_t) -1)

      g_string_append_printf (ret, "gid=%" G_GINT64_FORMAT ",", (gint64) id);

    if (ret->str[ret->len - 1] == ',')

      ret->str[ret->len - 1] = '\0';

  }

#else

  g_string_append (ret, "unknown");

#endif

  return g_string_free (ret, FALSE);

}

/* ---------------------------------------------------------------------------------------------------- */

#if G_CREDENTIALS_USE_LINUX_UCRED

/*

 * Check whether @native contains invalid data. If getsockopt SO_PEERCRED

 * is used on a TCP socket, it succeeds but yields a credentials structure

 * with pid 0, uid -1 and gid -1. Similarly, if SO_PASSCRED is used on a

 * receiving Unix socket when the sending socket did not also enable

 * SO_PASSCRED, it can succeed but yield a credentials structure with

 * pid 0, uid /proc/sys/kernel/overflowuid and gid

 * /proc/sys/kernel/overflowgid.

 */

static gboolean

linux_ucred_check_valid (struct ucred  *native,

                         GError       **error)

{

  if (native->pid == 0

      || native->uid == (uid_t) -1

      || native->gid == (gid_t) -1)

    {

      g_set_error_literal (error,

                           G_IO_ERROR,

                           G_IO_ERROR_INVALID_DATA,

                           _("GCredentials contains invalid data"));

      return FALSE;

    }

  return TRUE;

}

#endif

/**

 * g_credentials_is_same_user:

 * @credentials: A #GCredentials.

 * @other_credentials: A #GCredentials.

 * @error: Return location for error or %NULL.

 *

 * Checks if @credentials and @other_credentials is the same user.

 *

 * This operation can fail if #GCredentials is not supported on the

 * the OS.

 *

 * Returns: %TRUE if @credentials and @other_credentials has the same

 * user, %FALSE otherwise or if @error is set.

 *

 * Since: 2.26

 */

gboolean

g_credentials_is_same_user (GCredentials  *credentials,

                            GCredentials  *other_credentials,

                            GError       **error)

{

  gboolean ret;

  g_return_val_if_fail (G_IS_CREDENTIALS (credentials), FALSE);

  g_return_val_if_fail (G_IS_CREDENTIALS (other_credentials), FALSE);

  g_return_val_if_fail (error == NULL || *error == NULL, FALSE);

  ret = FALSE;

#if G_CREDENTIALS_USE_LINUX_UCRED

  if (linux_ucred_check_valid (&credentials->native, NULL)

      && credentials->native.uid == other_credentials->native.uid)

    ret = TRUE;

#elif G_CREDENTIALS_USE_APPLE_XUCRED

  if (credentials->native.cr_version == other_credentials->native.cr_version &&

      credentials->native.cr_uid == other_credentials->native.cr_uid)

    ret = TRUE;

#elif G_CREDENTIALS_USE_FREEBSD_CMSGCRED

  if (credentials->native.cmcred_euid == other_credentials->native.cmcred_euid)

    ret = TRUE;

#elif G_CREDENTIALS_USE_NETBSD_UNPCBID

  if (credentials->native.unp_euid == other_credentials->native.unp_euid)

    ret = TRUE;

#elif G_CREDENTIALS_USE_OPENBSD_SOCKPEERCRED

  if (credentials->native.uid == other_credentials->native.uid)

    ret = TRUE;

#elif G_CREDENTIALS_USE_SOLARIS_UCRED

  if (ucred_geteuid (credentials->native) == ucred_geteuid (other_credentials->native))

    ret = TRUE;

#else

  g_set_error_literal (error,

                       G_IO_ERROR,

                       G_IO_ERROR_NOT_SUPPORTED,

                       _("GCredentials is not implemented on this OS"));

#endif

  return ret;

}

static gboolean

credentials_native_type_check (GCredentialsType  requested_type,

                               const char       *op)

{

  GEnumClass *enum_class;

  GEnumValue *requested;

#if G_CREDENTIALS_SUPPORTED

  GEnumValue *supported;

#endif

#if G_CREDENTIALS_SUPPORTED

  if (requested_type == G_CREDENTIALS_NATIVE_TYPE)

    return TRUE;

#endif

  enum_class = g_type_class_ref (g_credentials_type_get_type ());

  requested = g_enum_get_value (enum_class, requested_type);

#if G_CREDENTIALS_SUPPORTED

  supported = g_enum_get_value (enum_class, G_CREDENTIALS_NATIVE_TYPE);

  g_assert (supported);

  g_warning ("g_credentials_%s_native: Trying to %s credentials of type %s "

             "but only %s is supported on this platform.",

             op, op,

             requested ? requested->value_name : "(unknown)",

             supported->value_name);

#else

  g_warning ("g_credentials_%s_native: Trying to %s credentials of type %s "

             "but there is no support for GCredentials on this platform.",

             op, op,

             requested ? requested->value_name : "(unknown)");

#endif

  g_type_class_unref (enum_class);

  return FALSE;

}

/**

 * g_credentials_get_native: (skip)

 * @credentials: A #GCredentials.

 * @native_type: The type of native credentials to get.

 *

 * Gets a pointer to native credentials of type @native_type from

 * @credentials.

 *

 * It is a programming error (which will cause a warning to be

 * logged) to use this method if there is no #GCredentials support for

 * the OS or if @native_type isn't supported by the OS.

 *

 * Returns: (transfer none) (nullable): The pointer to native credentials or

 *     %NULL if there is no #GCredentials support for the OS or if @native_type

 *     isn't supported by the OS. Do not free the returned data, it is owned

 *     by @credentials.

 *

 * Since: 2.26

 */

gpointer

g_credentials_get_native (GCredentials     *credentials,

                          GCredentialsType  native_type)

{

  g_return_val_if_fail (G_IS_CREDENTIALS (credentials), NULL);

  if (!credentials_native_type_check (native_type, "get"))

    return NULL;

#if G_CREDENTIALS_USE_SOLARIS_UCRED

  return credentials->native;

#elif G_CREDENTIALS_SUPPORTED

  return &credentials->native;

#else

  g_assert_not_reached ();

#endif

}

/**

 * g_credentials_set_native:

 * @credentials: A #GCredentials.

 * @native_type: The type of native credentials to set.

 * @native: (not nullable): A pointer to native credentials.

 *

 * Copies the native credentials of type @native_type from @native

 * into @credentials.

 *

 * It is a programming error (which will cause a warning to be

 * logged) to use this method if there is no #GCredentials support for

 * the OS or if @native_type isn't supported by the OS.

 *

 * Since: 2.26

 */

void

g_credentials_set_native (GCredentials     *credentials,

                          GCredentialsType  native_type,

                          gpointer          native)

{

  if (!credentials_native_type_check (native_type, "set"))

    return;

#if G_CREDENTIALS_USE_SOLARIS_UCRED

  memcpy (credentials->native, native, ucred_size ());

#elif G_CREDENTIALS_SUPPORTED

  memcpy (&credentials->native, native, sizeof (credentials->native));

#else

  g_assert_not_reached ();

#endif

}

/* ---------------------------------------------------------------------------------------------------- */

#ifdef G_OS_UNIX

/**

 * g_credentials_get_unix_user:

 * @credentials: A #GCredentials

 * @error: Return location for error or %NULL.

 *

 * Tries to get the UNIX user identifier from @credentials. This

 * method is only available on UNIX platforms.

 *

 * This operation can fail if #GCredentials is not supported on the

 * OS or if the native credentials type does not contain information

 * about the UNIX user.

 *

 * Returns: The UNIX user identifier or `-1` if @error is set.

 *

 * Since: 2.26

 */

uid_t

g_credentials_get_unix_user (GCredentials    *credentials,

                             GError         **error)

{

  uid_t ret;

  g_return_val_if_fail (G_IS_CREDENTIALS (credentials), -1);

  g_return_val_if_fail (error == NULL || *error == NULL, -1);

#if G_CREDENTIALS_USE_LINUX_UCRED

  if (linux_ucred_check_valid (&credentials->native, error))

    ret = credentials->native.uid;

  else

    ret = -1;

#elif G_CREDENTIALS_USE_APPLE_XUCRED

  if (credentials->native.cr_version == XUCRED_VERSION)

    {

      ret = credentials->native.cr_uid;

    }

  else

    {

      g_set_error (error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED,

                   /* No point in translating the part in parentheses... */

                   "%s (struct xucred cr_version %u != %u)",

                   _("There is no GCredentials support for your platform"),

                   credentials->native.cr_version,

                   XUCRED_VERSION);

      ret = -1;

    }

#elif G_CREDENTIALS_USE_FREEBSD_CMSGCRED

  ret = credentials->native.cmcred_euid;

#elif G_CREDENTIALS_USE_NETBSD_UNPCBID

  ret = credentials->native.unp_euid;

#elif G_CREDENTIALS_USE_OPENBSD_SOCKPEERCRED

  ret = credentials->native.uid;

#elif G_CREDENTIALS_USE_SOLARIS_UCRED

  ret = ucred_geteuid (credentials->native);

#else

  ret = -1;

  g_set_error_literal (error,

                       G_IO_ERROR,

                       G_IO_ERROR_NOT_SUPPORTED,

                       _("There is no GCredentials support for your platform"));

#endif

  return ret;

}

/**

 * g_credentials_get_unix_pid:

 * @credentials: A #GCredentials

 * @error: Return location for error or %NULL.

 *

 * Tries to get the UNIX process identifier from @credentials. This

 * method is only available on UNIX platforms.

 *

 * This operation can fail if #GCredentials is not supported on the

 * OS or if the native credentials type does not contain information

 * about the UNIX process ID (for example this is the case for

 * %G_CREDENTIALS_TYPE_APPLE_XUCRED).

 *

 * Returns: The UNIX process ID, or `-1` if @error is set.

 *

 * Since: 2.36

 */

pid_t

g_credentials_get_unix_pid (GCredentials    *credentials,

                            GError         **error)

{

  pid_t ret;

  g_return_val_if_fail (G_IS_CREDENTIALS (credentials), -1);

  g_return_val_if_fail (error == NULL || *error == NULL, -1);

#if G_CREDENTIALS_USE_LINUX_UCRED

  if (linux_ucred_check_valid (&credentials->native, error))

    ret = credentials->native.pid;

  else

    ret = -1;

#elif G_CREDENTIALS_USE_FREEBSD_CMSGCRED

  ret = credentials->native.cmcred_pid;

#elif G_CREDENTIALS_USE_NETBSD_UNPCBID

  ret = credentials->native.unp_pid;

#elif G_CREDENTIALS_USE_OPENBSD_SOCKPEERCRED

  ret = credentials->native.pid;

#elif G_CREDENTIALS_USE_SOLARIS_UCRED

  ret = ucred_getpid (credentials->native);

#else

  /* this case includes G_CREDENTIALS_USE_APPLE_XUCRED */

  ret = -1;

  g_set_error_literal (error,

                       G_IO_ERROR,

                       G_IO_ERROR_NOT_SUPPORTED,

                       _("GCredentials does not contain a process ID on this OS"));

#endif

  return ret;

}

/**

 * g_credentials_set_unix_user:

 * @credentials: A #GCredentials.

 * @uid: The UNIX user identifier to set.

 * @error: Return location for error or %NULL.

 *

 * Tries to set the UNIX user identifier on @credentials. This method

 * is only available on UNIX platforms.

 *

 * This operation can fail if #GCredentials is not supported on the

 * OS or if the native credentials type does not contain information

 * about the UNIX user. It can also fail if the OS does not allow the

 * use of "spoofed" credentials.

 *

 * Returns: %TRUE if @uid was set, %FALSE if error is set.

 *

 * Since: 2.26

 */

gboolean

g_credentials_set_unix_user (GCredentials    *credentials,

                             uid_t            uid,

                             GError         **error)

{

  gboolean ret = FALSE;

  g_return_val_if_fail (G_IS_CREDENTIALS (credentials), FALSE);

  g_return_val_if_fail (uid != (uid_t) -1, FALSE);

  g_return_val_if_fail (error == NULL || *error == NULL, FALSE);

#if G_CREDENTIALS_USE_LINUX_UCRED

  credentials->native.uid = uid;

  ret = TRUE;

#elif G_CREDENTIALS_USE_APPLE_XUCRED

  credentials->native.cr_uid = uid;

  ret = TRUE;

#elif G_CREDENTIALS_USE_FREEBSD_CMSGCRED

  credentials->native.cmcred_euid = uid;

  ret = TRUE;

#elif G_CREDENTIALS_USE_NETBSD_UNPCBID

  credentials->native.unp_euid = uid;

  ret = TRUE;

#elif G_CREDENTIALS_USE_OPENBSD_SOCKPEERCRED

  credentials->native.uid = uid;

  ret = TRUE;

#elif !G_CREDENTIALS_SPOOFING_SUPPORTED

  g_set_error_literal (error,

                       G_IO_ERROR,

                       G_IO_ERROR_PERMISSION_DENIED,

                       _("Credentials spoofing is not possible on this OS"));

  ret = FALSE;

#else

  g_set_error_literal (error,

                       G_IO_ERROR,

                       G_IO_ERROR_NOT_SUPPORTED,

                       _("GCredentials is not implemented on this OS"));

  ret = FALSE;

#endif

  return ret;

}

#endif /* G_OS_UNIX */