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glib/gio/gdbusauth.c
Sophie Herold 0d268c4825 Remove all nicks and blurbs from param specs 
Nicks and blurbs don't have any practical use for gio/gobject libraries.
Leaving tests untouched since this features is still used by other libraries.

Closes #2991
2023-11-29 13:41:34 +00:00

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/* GDBus - GLib D-Bus Library
*
* Copyright (C) 2008-2010 Red Hat, Inc.
*
* SPDX-License-Identifier: LGPL-2.1-or-later
*
* 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 "gdbusauth.h"
#include "gdbusauthmechanismanon.h"
#include "gdbusauthmechanismexternal.h"
#include "gdbusauthmechanismsha1.h"
#include "gdbusauthobserver.h"
#include "gdbuserror.h"
#include "gdbusutils.h"
#include "gioenumtypes.h"
#include "gcredentials.h"
#include "gcredentialsprivate.h"
#include "gdbusprivate.h"
#include "giostream.h"
#include "gdatainputstream.h"
#include "gdataoutputstream.h"
#include "gnetworking.h"
#include "gunixconnection.h"
#include "gunixcredentialsmessage.h"
#include "glibintl.h"
G_GNUC_PRINTF(1, 2)
static void
debug_print (const gchar *message, ...)
{
if (G_UNLIKELY (_g_dbus_debug_authentication ()))
{
gchar *s;
GString *str;
va_list var_args;
guint n;
_g_dbus_debug_print_lock ();
va_start (var_args, message);
s = g_strdup_vprintf (message, var_args);
va_end (var_args);
str = g_string_new (NULL);
for (n = 0; s[n] != '\0'; n++)
{
if (G_UNLIKELY (s[n] == '\r'))
g_string_append (str, "\\r");
else if (G_UNLIKELY (s[n] == '\n'))
g_string_append (str, "\\n");
else
g_string_append_c (str, s[n]);
}
g_print ("GDBus-debug:Auth: %s\n", str->str);
g_string_free (str, TRUE);
g_free (s);
_g_dbus_debug_print_unlock ();
}
}
typedef struct
{
const gchar *name;
gint priority;
GType gtype;
} Mechanism;
static void mechanism_free (Mechanism *m);
struct _GDBusAuthPrivate
{
GIOStream *stream;
/* A list of available Mechanism, sorted according to priority */
GList *available_mechanisms;
};
enum
{
PROP_0,
PROP_STREAM
};
G_DEFINE_TYPE_WITH_PRIVATE (GDBusAuth, _g_dbus_auth, G_TYPE_OBJECT)
/* ---------------------------------------------------------------------------------------------------- */
static void
_g_dbus_auth_finalize (GObject *object)
{
GDBusAuth *auth = G_DBUS_AUTH (object);
if (auth->priv->stream != NULL)
g_object_unref (auth->priv->stream);
g_list_free_full (auth->priv->available_mechanisms, (GDestroyNotify) mechanism_free);
if (G_OBJECT_CLASS (_g_dbus_auth_parent_class)->finalize != NULL)
G_OBJECT_CLASS (_g_dbus_auth_parent_class)->finalize (object);
}
static void
_g_dbus_auth_get_property (GObject *object,
guint prop_id,
GValue *value,
GParamSpec *pspec)
{
GDBusAuth *auth = G_DBUS_AUTH (object);
switch (prop_id)
{
case PROP_STREAM:
g_value_set_object (value, auth->priv->stream);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static void
_g_dbus_auth_set_property (GObject *object,
guint prop_id,
const GValue *value,
GParamSpec *pspec)
{
GDBusAuth *auth = G_DBUS_AUTH (object);
switch (prop_id)
{
case PROP_STREAM:
auth->priv->stream = g_value_dup_object (value);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static void
_g_dbus_auth_class_init (GDBusAuthClass *klass)
{
GObjectClass *gobject_class;
gobject_class = G_OBJECT_CLASS (klass);
gobject_class->get_property = _g_dbus_auth_get_property;
gobject_class->set_property = _g_dbus_auth_set_property;
gobject_class->finalize = _g_dbus_auth_finalize;
g_object_class_install_property (gobject_class,
PROP_STREAM,
g_param_spec_object ("stream", NULL, NULL,
G_TYPE_IO_STREAM,
G_PARAM_READABLE |
G_PARAM_WRITABLE |
G_PARAM_CONSTRUCT_ONLY |
G_PARAM_STATIC_NAME |
G_PARAM_STATIC_BLURB |
G_PARAM_STATIC_NICK));
}
static void
mechanism_free (Mechanism *m)
{
g_free (m);
}
static void
add_mechanism (GDBusAuth *auth,
GDBusAuthObserver *observer,
GType mechanism_type)
{
const gchar *name;
name = _g_dbus_auth_mechanism_get_name (mechanism_type);
if (observer == NULL || g_dbus_auth_observer_allow_mechanism (observer, name))
{
Mechanism *m;
m = g_new0 (Mechanism, 1);
m->name = name;
m->priority = _g_dbus_auth_mechanism_get_priority (mechanism_type);
m->gtype = mechanism_type;
auth->priv->available_mechanisms = g_list_prepend (auth->priv->available_mechanisms, m);
}
}
static gint
mech_compare_func (Mechanism *a, Mechanism *b)
{
gint ret;
/* ensure deterministic order */
ret = b->priority - a->priority;
if (ret == 0)
ret = g_strcmp0 (b->name, a->name);
return ret;
}
static void
_g_dbus_auth_init (GDBusAuth *auth)
{
auth->priv = _g_dbus_auth_get_instance_private (auth);
}
static void
_g_dbus_auth_add_mechs (GDBusAuth *auth,
GDBusAuthObserver *observer)
{
/* TODO: trawl extension points */
add_mechanism (auth, observer, G_TYPE_DBUS_AUTH_MECHANISM_ANON);
add_mechanism (auth, observer, G_TYPE_DBUS_AUTH_MECHANISM_SHA1);
add_mechanism (auth, observer, G_TYPE_DBUS_AUTH_MECHANISM_EXTERNAL);
auth->priv->available_mechanisms = g_list_sort (auth->priv->available_mechanisms,
(GCompareFunc) mech_compare_func);
}
static GType
find_mech_by_name (GDBusAuth *auth,
const gchar *name)
{
GType ret;
GList *l;
ret = (GType) 0;
for (l = auth->priv->available_mechanisms; l != NULL; l = l->next)
{
Mechanism *m = l->data;
if (g_strcmp0 (name, m->name) == 0)
{
ret = m->gtype;
goto out;
}
}
out:
return ret;
}
GDBusAuth *
_g_dbus_auth_new (GIOStream *stream)
{
return g_object_new (G_TYPE_DBUS_AUTH,
"stream", stream,
NULL);
}
/* ---------------------------------------------------------------------------------------------------- */
/* like g_data_input_stream_read_line() but sets error if there's no content to read */
static gchar *
_my_g_data_input_stream_read_line (GDataInputStream *dis,
gsize *out_line_length,
GCancellable *cancellable,
GError **error)
{
gchar *ret;
g_return_val_if_fail (error == NULL || *error == NULL, NULL);
ret = g_data_input_stream_read_line (dis,
out_line_length,
cancellable,
error);
if (ret == NULL && error != NULL && *error == NULL)
{
g_set_error_literal (error,
G_IO_ERROR,
G_IO_ERROR_FAILED,
_("Unexpected lack of content trying to read a line"));
}
return ret;
}
/* This function is to avoid situations like this
*
* BEGIN\r\nl\0\0\1...
*
* e.g. where we read into the first D-Bus message while waiting for
* the final line from the client (TODO: file bug against gio for
* this)
*/
static gchar *
_my_g_input_stream_read_line_safe (GInputStream *i,
gsize *out_line_length,
GCancellable *cancellable,
GError **error)
{
GString *str;
gchar c;
gssize num_read;
gboolean last_was_cr;
str = g_string_new (NULL);
last_was_cr = FALSE;
while (TRUE)
{
num_read = g_input_stream_read (i,
&c,
1,
cancellable,
error);
if (num_read == -1)
goto fail;
if (num_read == 0)
{
if (error != NULL && *error == NULL)
{
g_set_error_literal (error,
G_IO_ERROR,
G_IO_ERROR_FAILED,
_("Unexpected lack of content trying to (safely) read a line"));
}
goto fail;
}
g_string_append_c (str, (gint) c);
if (last_was_cr)
{
if (c == 0x0a)
{
g_assert (str->len >= 2);
g_string_set_size (str, str->len - 2);
goto out;
}
}
last_was_cr = (c == 0x0d);
}
out:
if (out_line_length != NULL)
*out_line_length = str->len;
return g_string_free (str, FALSE);
fail:
g_assert (error == NULL || *error != NULL);
g_string_free (str, TRUE);
return NULL;
}
/* ---------------------------------------------------------------------------------------------------- */
static gchar *
hexdecode (const gchar *str,
gsize *out_len,
GError **error)
{
gchar *ret;
GString *s;
guint n;
ret = NULL;
s = g_string_new (NULL);
for (n = 0; str[n] != '\0'; n += 2)
{
gint upper_nibble;
gint lower_nibble;
guint value;
upper_nibble = g_ascii_xdigit_value (str[n]);
lower_nibble = g_ascii_xdigit_value (str[n + 1]);
if (upper_nibble == -1 || lower_nibble == -1)
{
g_set_error (error,
G_IO_ERROR,
G_IO_ERROR_FAILED,
"Error hexdecoding string '%s' around position %d",
str, n);
goto out;
}
value = (upper_nibble<<4) | lower_nibble;
g_string_append_c (s, value);
}
*out_len = s->len;
ret = g_string_free (s, FALSE);
s = NULL;
out:
if (s != NULL)
{
*out_len = 0;
g_string_free (s, TRUE);
}
return ret;
}
/* ---------------------------------------------------------------------------------------------------- */
static GDBusAuthMechanism *
client_choose_mech_and_send_initial_response (GDBusAuth *auth,
GCredentials *credentials_that_were_sent,
GDBusConnectionFlags conn_flags,
const gchar* const *supported_auth_mechs,
GPtrArray *attempted_auth_mechs,
GDataOutputStream *dos,
GCancellable *cancellable,
GError **error)
{
GDBusAuthMechanism *mech;
GType auth_mech_to_use_gtype;
guint n;
guint m;
gchar *initial_response;
gsize initial_response_len;
gchar *encoded;
gchar *s;
again:
mech = NULL;
debug_print ("CLIENT: Trying to choose mechanism");
/* find an authentication mechanism to try, if any */
auth_mech_to_use_gtype = (GType) 0;
for (n = 0; supported_auth_mechs[n] != NULL; n++)
{
gboolean attempted_already;
attempted_already = FALSE;
for (m = 0; m < attempted_auth_mechs->len; m++)
{
if (g_strcmp0 (supported_auth_mechs[n], attempted_auth_mechs->pdata[m]) == 0)
{
attempted_already = TRUE;
break;
}
}
if (!attempted_already)
{
auth_mech_to_use_gtype = find_mech_by_name (auth, supported_auth_mechs[n]);
if (auth_mech_to_use_gtype != (GType) 0)
break;
}
}
if (auth_mech_to_use_gtype == (GType) 0)
{
gchar *available;
GString *tried_str;
debug_print ("CLIENT: Exhausted all available mechanisms");
available = g_strjoinv (", ", (gchar **) supported_auth_mechs);
tried_str = g_string_new (NULL);
for (n = 0; n < attempted_auth_mechs->len; n++)
{
if (n > 0)
g_string_append (tried_str, ", ");
g_string_append (tried_str, attempted_auth_mechs->pdata[n]);
}
g_set_error (error,
G_IO_ERROR,
G_IO_ERROR_FAILED,
_("Exhausted all available authentication mechanisms (tried: %s) (available: %s)"),
tried_str->str,
available);
g_string_free (tried_str, TRUE);
g_free (available);
goto out;
}
/* OK, decided on a mechanism - let's do this thing */
mech = g_object_new (auth_mech_to_use_gtype,
"stream", auth->priv->stream,
"credentials", credentials_that_were_sent,
NULL);
debug_print ("CLIENT: Trying mechanism '%s'", _g_dbus_auth_mechanism_get_name (auth_mech_to_use_gtype));
g_ptr_array_add (attempted_auth_mechs, (gpointer) _g_dbus_auth_mechanism_get_name (auth_mech_to_use_gtype));
/* the auth mechanism may not be supported
* (for example, EXTERNAL only works if credentials were exchanged)
*/
if (!_g_dbus_auth_mechanism_is_supported (mech))
{
debug_print ("CLIENT: Mechanism '%s' says it is not supported", _g_dbus_auth_mechanism_get_name (auth_mech_to_use_gtype));
g_object_unref (mech);
mech = NULL;
goto again;
}
initial_response_len = 0;
initial_response = _g_dbus_auth_mechanism_client_initiate (mech,
conn_flags,
&initial_response_len);
#if 0
g_printerr ("using auth mechanism with name '%s' of type '%s' with initial response '%s'\n",
_g_dbus_auth_mechanism_get_name (auth_mech_to_use_gtype),
g_type_name (G_TYPE_FROM_INSTANCE (mech)),
initial_response);
#endif
if (initial_response != NULL)
{
//g_printerr ("initial_response = '%s'\n", initial_response);
encoded = _g_dbus_hexencode (initial_response, initial_response_len);
s = g_strdup_printf ("AUTH %s %s\r\n",
_g_dbus_auth_mechanism_get_name (auth_mech_to_use_gtype),
encoded);
g_free (initial_response);
g_free (encoded);
}
else
{
s = g_strdup_printf ("AUTH %s\r\n", _g_dbus_auth_mechanism_get_name (auth_mech_to_use_gtype));
}
debug_print ("CLIENT: writing '%s'", s);
if (!g_data_output_stream_put_string (dos, s, cancellable, error))
{
g_object_unref (mech);
mech = NULL;
g_free (s);
goto out;
}
g_free (s);
out:
return mech;
}
/* ---------------------------------------------------------------------------------------------------- */
typedef enum
{
CLIENT_STATE_WAITING_FOR_DATA,
CLIENT_STATE_WAITING_FOR_OK,
CLIENT_STATE_WAITING_FOR_REJECT,
CLIENT_STATE_WAITING_FOR_AGREE_UNIX_FD
} ClientState;
gchar *
_g_dbus_auth_run_client (GDBusAuth *auth,
GDBusAuthObserver *observer,
GDBusConnectionFlags conn_flags,
GDBusCapabilityFlags offered_capabilities,
GDBusCapabilityFlags *out_negotiated_capabilities,
GCancellable *cancellable,
GError **error)
{
gchar *s;
GDataInputStream *dis;
GDataOutputStream *dos;
GCredentials *credentials;
gchar *ret_guid;
gchar *line;
gsize line_length;
gchar **supported_auth_mechs;
GPtrArray *attempted_auth_mechs;
GDBusAuthMechanism *mech;
ClientState state;
GDBusCapabilityFlags negotiated_capabilities;
g_return_val_if_fail ((conn_flags & G_DBUS_CONNECTION_FLAGS_AUTHENTICATION_CLIENT), NULL);
g_return_val_if_fail (!(conn_flags & G_DBUS_CONNECTION_FLAGS_AUTHENTICATION_SERVER), NULL);
debug_print ("CLIENT: initiating");
_g_dbus_auth_add_mechs (auth, observer);
ret_guid = NULL;
supported_auth_mechs = NULL;
attempted_auth_mechs = g_ptr_array_new ();
mech = NULL;
negotiated_capabilities = 0;
credentials = NULL;
dis = G_DATA_INPUT_STREAM (g_data_input_stream_new (g_io_stream_get_input_stream (auth->priv->stream)));
dos = G_DATA_OUTPUT_STREAM (g_data_output_stream_new (g_io_stream_get_output_stream (auth->priv->stream)));
g_filter_input_stream_set_close_base_stream (G_FILTER_INPUT_STREAM (dis), FALSE);
g_filter_output_stream_set_close_base_stream (G_FILTER_OUTPUT_STREAM (dos), FALSE);
g_data_input_stream_set_newline_type (dis, G_DATA_STREAM_NEWLINE_TYPE_CR_LF);
#ifdef G_OS_UNIX
if (G_IS_UNIX_CONNECTION (auth->priv->stream))
{
credentials = g_credentials_new ();
if (!g_unix_connection_send_credentials (G_UNIX_CONNECTION (auth->priv->stream),
cancellable,
error))
goto out;
}
else
{
if (!g_data_output_stream_put_byte (dos, '\0', cancellable, error))
goto out;
}
#else
if (!g_data_output_stream_put_byte (dos, '\0', cancellable, error))
goto out;
#endif
if (credentials != NULL)
{
if (G_UNLIKELY (_g_dbus_debug_authentication ()))
{
s = g_credentials_to_string (credentials);
debug_print ("CLIENT: sent credentials '%s'", s);
g_free (s);
}
}
else
{
debug_print ("CLIENT: didn't send any credentials");
}
/* TODO: to reduce roundtrips, try to pick an auth mechanism to start with */
/* Get list of supported authentication mechanisms */
s = "AUTH\r\n";
debug_print ("CLIENT: writing '%s'", s);
if (!g_data_output_stream_put_string (dos, s, cancellable, error))
goto out;
state = CLIENT_STATE_WAITING_FOR_REJECT;
while (TRUE)
{
switch (state)
{
case CLIENT_STATE_WAITING_FOR_REJECT:
debug_print ("CLIENT: WaitingForReject");
line = _my_g_data_input_stream_read_line (dis, &line_length, cancellable, error);
if (line == NULL)
goto out;
debug_print ("CLIENT: WaitingForReject, read '%s'", line);
choose_mechanism:
if (!g_str_has_prefix (line, "REJECTED "))
{
g_set_error (error,
G_IO_ERROR,
G_IO_ERROR_FAILED,
"In WaitingForReject: Expected 'REJECTED am1 am2 ... amN', got '%s'",
line);
g_free (line);
goto out;
}
if (supported_auth_mechs == NULL)
{
supported_auth_mechs = g_strsplit (line + sizeof ("REJECTED ") - 1, " ", 0);
#if 0
for (n = 0; supported_auth_mechs != NULL && supported_auth_mechs[n] != NULL; n++)
g_printerr ("supported_auth_mechs[%d] = '%s'\n", n, supported_auth_mechs[n]);
#endif
}
g_free (line);
mech = client_choose_mech_and_send_initial_response (auth,
credentials,
conn_flags,
(const gchar* const *) supported_auth_mechs,
attempted_auth_mechs,
dos,
cancellable,
error);
if (mech == NULL)
goto out;
if (_g_dbus_auth_mechanism_client_get_state (mech) == G_DBUS_AUTH_MECHANISM_STATE_WAITING_FOR_DATA)
state = CLIENT_STATE_WAITING_FOR_DATA;
else
state = CLIENT_STATE_WAITING_FOR_OK;
break;
case CLIENT_STATE_WAITING_FOR_OK:
debug_print ("CLIENT: WaitingForOK");
line = _my_g_data_input_stream_read_line (dis, &line_length, cancellable, error);
if (line == NULL)
goto out;
debug_print ("CLIENT: WaitingForOK, read '%s'", line);
if (g_str_has_prefix (line, "OK "))
{
if (!g_dbus_is_guid (line + 3))
{
g_set_error (error,
G_IO_ERROR,
G_IO_ERROR_FAILED,
"Invalid OK response '%s'",
line);
g_free (line);
goto out;
}
ret_guid = g_strdup (line + 3);
g_free (line);
if (offered_capabilities & G_DBUS_CAPABILITY_FLAGS_UNIX_FD_PASSING)
{
s = "NEGOTIATE_UNIX_FD\r\n";
debug_print ("CLIENT: writing '%s'", s);
if (!g_data_output_stream_put_string (dos, s, cancellable, error))
goto out;
state = CLIENT_STATE_WAITING_FOR_AGREE_UNIX_FD;
}
else
{
s = "BEGIN\r\n";
debug_print ("CLIENT: writing '%s'", s);
if (!g_data_output_stream_put_string (dos, s, cancellable, error))
goto out;
/* and we're done! */
goto out;
}
}
else if (g_str_has_prefix (line, "REJECTED "))
{
goto choose_mechanism;
}
else
{
/* TODO: handle other valid responses */
g_set_error (error,
G_IO_ERROR,
G_IO_ERROR_FAILED,
"In WaitingForOk: unexpected response '%s'",
line);
g_free (line);
goto out;
}
break;
case CLIENT_STATE_WAITING_FOR_AGREE_UNIX_FD:
debug_print ("CLIENT: WaitingForAgreeUnixFD");
line = _my_g_data_input_stream_read_line (dis, &line_length, cancellable, error);
if (line == NULL)
goto out;
debug_print ("CLIENT: WaitingForAgreeUnixFD, read='%s'", line);
if (g_strcmp0 (line, "AGREE_UNIX_FD") == 0)
{
g_free (line);
negotiated_capabilities |= G_DBUS_CAPABILITY_FLAGS_UNIX_FD_PASSING;
s = "BEGIN\r\n";
debug_print ("CLIENT: writing '%s'", s);
if (!g_data_output_stream_put_string (dos, s, cancellable, error))
goto out;
/* and we're done! */
goto out;
}
else if (g_str_has_prefix (line, "ERROR") && (line[5] == 0 || g_ascii_isspace (line[5])))
{
//g_strstrip (line + 5); g_debug ("bah, no unix_fd: '%s'", line + 5);
g_free (line);
s = "BEGIN\r\n";
debug_print ("CLIENT: writing '%s'", s);
if (!g_data_output_stream_put_string (dos, s, cancellable, error))
goto out;
/* and we're done! */
goto out;
}
else
{
/* TODO: handle other valid responses */
g_set_error (error,
G_IO_ERROR,
G_IO_ERROR_FAILED,
"In WaitingForAgreeUnixFd: unexpected response '%s'",
line);
g_free (line);
goto out;
}
break;
case CLIENT_STATE_WAITING_FOR_DATA:
debug_print ("CLIENT: WaitingForData");
line = _my_g_data_input_stream_read_line (dis, &line_length, cancellable, error);
if (line == NULL)
goto out;
debug_print ("CLIENT: WaitingForData, read='%s'", line);
if (g_str_equal (line, "DATA") || g_str_has_prefix (line, "DATA "))
{
gchar *encoded;
gchar *decoded_data;
gsize decoded_data_len = 0;
encoded = g_strdup (line + 4);
g_free (line);
g_strstrip (encoded);
decoded_data = hexdecode (encoded, &decoded_data_len, error);
g_free (encoded);
if (decoded_data == NULL)
{
g_prefix_error (error, "DATA response is malformed: ");
/* invalid encoding, disconnect! */
goto out;
}
_g_dbus_auth_mechanism_client_data_receive (mech, decoded_data, decoded_data_len);
g_free (decoded_data);
if (_g_dbus_auth_mechanism_client_get_state (mech) == G_DBUS_AUTH_MECHANISM_STATE_HAVE_DATA_TO_SEND)
{
gchar *data;
gsize data_len;
data = _g_dbus_auth_mechanism_client_data_send (mech, &data_len);
if (data_len == 0)
{
s = g_strdup ("DATA\r\n");
}
else
{
gchar *encoded_data = _g_dbus_hexencode (data, data_len);
s = g_strdup_printf ("DATA %s\r\n", encoded_data);
g_free (encoded_data);
}
g_free (data);
debug_print ("CLIENT: writing '%s'", s);
if (!g_data_output_stream_put_string (dos, s, cancellable, error))
{
g_free (s);
goto out;
}
g_free (s);
}
state = CLIENT_STATE_WAITING_FOR_OK;
}
else if (g_str_has_prefix (line, "REJECTED "))
{
/* could be the chosen authentication method just doesn't work. Try
* another one...
*/
goto choose_mechanism;
}
else
{
g_set_error (error,
G_IO_ERROR,
G_IO_ERROR_FAILED,
"In WaitingForData: unexpected response '%s'",
line);
g_free (line);
goto out;
}
break;
default:
g_assert_not_reached ();
break;
}
}; /* main authentication client loop */
out:
if (mech != NULL)
g_object_unref (mech);
g_ptr_array_unref (attempted_auth_mechs);
g_strfreev (supported_auth_mechs);
g_object_unref (dis);
g_object_unref (dos);
/* ensure return value is NULL if error is set */
if (error != NULL && *error != NULL)
{
g_free (ret_guid);
ret_guid = NULL;
}
if (ret_guid != NULL)
{
if (out_negotiated_capabilities != NULL)
*out_negotiated_capabilities = negotiated_capabilities;
}
if (credentials != NULL)
g_object_unref (credentials);
debug_print ("CLIENT: Done, authenticated=%d", ret_guid != NULL);
return ret_guid;
}
/* ---------------------------------------------------------------------------------------------------- */
static gchar *
get_auth_mechanisms (GDBusAuth *auth,
gboolean allow_anonymous,
const gchar *prefix,
const gchar *suffix,
const gchar *separator)
{
GList *l;
GString *str;
gboolean need_sep;
str = g_string_new (prefix);
need_sep = FALSE;
for (l = auth->priv->available_mechanisms; l != NULL; l = l->next)
{
Mechanism *m = l->data;
if (!allow_anonymous && g_strcmp0 (m->name, "ANONYMOUS") == 0)
continue;
if (need_sep)
g_string_append (str, separator);
g_string_append (str, m->name);
need_sep = TRUE;
}
g_string_append (str, suffix);
return g_string_free (str, FALSE);
}
typedef enum
{
SERVER_STATE_WAITING_FOR_AUTH,
SERVER_STATE_WAITING_FOR_DATA,
SERVER_STATE_WAITING_FOR_BEGIN
} ServerState;
gboolean
_g_dbus_auth_run_server (GDBusAuth *auth,
GDBusAuthObserver *observer,
const gchar *guid,
gboolean allow_anonymous,
gboolean require_same_user,
GDBusCapabilityFlags offered_capabilities,
GDBusCapabilityFlags *out_negotiated_capabilities,
GCredentials **out_received_credentials,
GCancellable *cancellable,
GError **error)
{
gboolean ret;
ServerState state;
GDataOutputStream *dos;
GError *local_error;
gchar *line;
gsize line_length;
GDBusAuthMechanism *mech;
gchar *s;
GDBusCapabilityFlags negotiated_capabilities;
GCredentials *credentials;
GCredentials *own_credentials = NULL;
debug_print ("SERVER: initiating");
_g_dbus_auth_add_mechs (auth, observer);
ret = FALSE;
dos = NULL;
mech = NULL;
negotiated_capabilities = 0;
credentials = NULL;
if (!g_dbus_is_guid (guid))
{
g_set_error (error,
G_IO_ERROR,
G_IO_ERROR_FAILED,
"The given GUID '%s' is not valid",
guid);
goto out;
}
/* We use an extremely slow (but reliable) line reader for input
* instead of something buffered - this basically does a recvfrom()
* system call per character
*
* (the problem with using GDataInputStream's read_line is that
* because of buffering it might start reading into the first D-Bus
* message that appears after "BEGIN\r\n"....)
*/
dos = G_DATA_OUTPUT_STREAM (g_data_output_stream_new (g_io_stream_get_output_stream (auth->priv->stream)));
g_filter_output_stream_set_close_base_stream (G_FILTER_OUTPUT_STREAM (dos), FALSE);
/* read the NUL-byte, possibly with credentials attached */
#ifndef G_CREDENTIALS_PREFER_MESSAGE_PASSING
if (G_IS_SOCKET_CONNECTION (auth->priv->stream))
{
GSocket *sock = g_socket_connection_get_socket (G_SOCKET_CONNECTION (auth->priv->stream));
local_error = NULL;
credentials = g_socket_get_credentials (sock, &local_error);
if (credentials == NULL && !g_error_matches (local_error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED))
{
g_propagate_error (error, local_error);
goto out;
}
else
{
/* Clear the error indicator, so we can retry with
* g_unix_connection_receive_credentials() if necessary */
g_clear_error (&local_error);
}
}
#endif
if (credentials == NULL && G_IS_UNIX_CONNECTION (auth->priv->stream))
{
local_error = NULL;
credentials = g_unix_connection_receive_credentials (G_UNIX_CONNECTION (auth->priv->stream),
cancellable,
&local_error);
if (credentials == NULL && !g_error_matches (local_error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED))
{
g_propagate_error (error, local_error);
goto out;
}
g_clear_error (&local_error);
}
else
{
gchar c;
gssize num_read;
local_error = NULL;
num_read = g_input_stream_read (g_io_stream_get_input_stream (auth->priv->stream),
&c, 1,
cancellable, &local_error);
if (num_read != 1 || local_error != NULL)
{
if (local_error == NULL)
g_set_error_literal (error,
G_IO_ERROR,
G_IO_ERROR_FAILED,
_ ("Unexpected lack of content trying to read a byte"));
else
g_propagate_error (error, local_error);
goto out;
}
}
if (credentials != NULL)
{
if (G_UNLIKELY (_g_dbus_debug_authentication ()))
{
s = g_credentials_to_string (credentials);
debug_print ("SERVER: received credentials '%s'", s);
g_free (s);
}
}
else
{
debug_print ("SERVER: didn't receive any credentials");
}
own_credentials = g_credentials_new ();
state = SERVER_STATE_WAITING_FOR_AUTH;
while (TRUE)
{
switch (state)
{
case SERVER_STATE_WAITING_FOR_AUTH:
debug_print ("SERVER: WaitingForAuth");
line = _my_g_input_stream_read_line_safe (g_io_stream_get_input_stream (auth->priv->stream),
&line_length,
cancellable,
error);
debug_print ("SERVER: WaitingForAuth, read '%s'", line);
if (line == NULL)
goto out;
if (g_strcmp0 (line, "AUTH") == 0)
{
s = get_auth_mechanisms (auth, allow_anonymous, "REJECTED ", "\r\n", " ");
debug_print ("SERVER: writing '%s'", s);
if (!g_data_output_stream_put_string (dos, s, cancellable, error))
{
g_free (s);
g_free (line);
goto out;
}
g_free (s);
g_free (line);
}
else if (g_str_has_prefix (line, "AUTH "))
{
gchar **tokens;
const gchar *encoded;
const gchar *mech_name;
GType auth_mech_to_use_gtype;
tokens = g_strsplit (line, " ", 0);
switch (g_strv_length (tokens))
{
case 2:
/* no initial response */
mech_name = tokens[1];
encoded = NULL;
break;
case 3:
/* initial response */
mech_name = tokens[1];
encoded = tokens[2];
break;
default:
g_set_error (error,
G_IO_ERROR,
G_IO_ERROR_FAILED,
"Unexpected line '%s' while in WaitingForAuth state",
line);
g_strfreev (tokens);
g_free (line);
goto out;
}
g_free (line);
/* TODO: record that the client has attempted to use this mechanism */
//g_debug ("client is trying '%s'", mech_name);
auth_mech_to_use_gtype = find_mech_by_name (auth, mech_name);
if ((auth_mech_to_use_gtype == (GType) 0) ||
(!allow_anonymous && g_strcmp0 (mech_name, "ANONYMOUS") == 0))
{
/* We don't support this auth mechanism */
g_strfreev (tokens);
s = get_auth_mechanisms (auth, allow_anonymous, "REJECTED ", "\r\n", " ");
debug_print ("SERVER: writing '%s'", s);
if (!g_data_output_stream_put_string (dos, s, cancellable, error))
{
g_free (s);
goto out;
}
g_free (s);
/* stay in WAITING FOR AUTH */
state = SERVER_STATE_WAITING_FOR_AUTH;
}
else
{
gchar *initial_response;
gsize initial_response_len;
g_clear_object (&mech);
mech = g_object_new (auth_mech_to_use_gtype,
"stream", auth->priv->stream,
"credentials", credentials,
NULL);
initial_response = NULL;
initial_response_len = 0;
if (encoded != NULL)
{
initial_response = hexdecode (encoded, &initial_response_len, error);
if (initial_response == NULL)
{
g_prefix_error (error, "Initial response is malformed: ");
/* invalid encoding, disconnect! */
g_strfreev (tokens);
goto out;
}
}
_g_dbus_auth_mechanism_server_initiate (mech,
initial_response,
initial_response_len);
g_free (initial_response);
g_strfreev (tokens);
change_state:
switch (_g_dbus_auth_mechanism_server_get_state (mech))
{
case G_DBUS_AUTH_MECHANISM_STATE_ACCEPTED:
if (require_same_user &&
(credentials == NULL ||
!g_credentials_is_same_user (credentials, own_credentials, NULL)))
{
/* disconnect */
g_set_error_literal (error,
G_IO_ERROR,
G_IO_ERROR_FAILED,
_("User IDs must be the same for peer and server"));
goto out;
}
else if (observer != NULL &&
!g_dbus_auth_observer_authorize_authenticated_peer (observer,
auth->priv->stream,
credentials))
{
/* disconnect */
g_set_error_literal (error,
G_IO_ERROR,
G_IO_ERROR_FAILED,
_("Cancelled via GDBusAuthObserver::authorize-authenticated-peer"));
goto out;
}
else
{
s = g_strdup_printf ("OK %s\r\n", guid);
debug_print ("SERVER: writing '%s'", s);
if (!g_data_output_stream_put_string (dos, s, cancellable, error))
{
g_free (s);
goto out;
}
g_free (s);
state = SERVER_STATE_WAITING_FOR_BEGIN;
}
break;
case G_DBUS_AUTH_MECHANISM_STATE_REJECTED:
s = get_auth_mechanisms (auth, allow_anonymous, "REJECTED ", "\r\n", " ");
debug_print ("SERVER: writing '%s'", s);
if (!g_data_output_stream_put_string (dos, s, cancellable, error))
{
g_free (s);
goto out;
}
g_free (s);
state = SERVER_STATE_WAITING_FOR_AUTH;
break;
case G_DBUS_AUTH_MECHANISM_STATE_WAITING_FOR_DATA:
state = SERVER_STATE_WAITING_FOR_DATA;
break;
case G_DBUS_AUTH_MECHANISM_STATE_HAVE_DATA_TO_SEND:
{
gchar *data;
gsize data_len;
data = _g_dbus_auth_mechanism_server_data_send (mech, &data_len);
if (data != NULL)
{
if (data_len == 0)
{
s = g_strdup ("DATA\r\n");
}
else
{
gchar *encoded_data = _g_dbus_hexencode (data, data_len);
s = g_strdup_printf ("DATA %s\r\n", encoded_data);
g_free (encoded_data);
}
g_free (data);
debug_print ("SERVER: writing '%s'", s);
if (!g_data_output_stream_put_string (dos, s, cancellable, error))
{
g_free (s);
goto out;
}
g_free (s);
}
}
goto change_state;
break;
default:
/* TODO */
g_assert_not_reached ();
break;
}
}
}
else
{
g_set_error (error,
G_IO_ERROR,
G_IO_ERROR_FAILED,
"Unexpected line '%s' while in WaitingForAuth state",
line);
g_free (line);
goto out;
}
break;
case SERVER_STATE_WAITING_FOR_DATA:
debug_print ("SERVER: WaitingForData");
line = _my_g_input_stream_read_line_safe (g_io_stream_get_input_stream (auth->priv->stream),
&line_length,
cancellable,
error);
debug_print ("SERVER: WaitingForData, read '%s'", line);
if (line == NULL)
goto out;
if (g_str_equal (line, "DATA") || g_str_has_prefix (line, "DATA "))
{
gchar *encoded;
gchar *decoded_data;
gsize decoded_data_len = 0;
encoded = g_strdup (line + 4);
g_free (line);
g_strstrip (encoded);
decoded_data = hexdecode (encoded, &decoded_data_len, error);
g_free (encoded);
if (decoded_data == NULL)
{
g_prefix_error (error, "DATA response is malformed: ");
/* invalid encoding, disconnect! */
goto out;
}
_g_dbus_auth_mechanism_server_data_receive (mech, decoded_data, decoded_data_len);
g_free (decoded_data);
/* oh man, this goto-crap is so ugly.. really need to rewrite the state machine */
goto change_state;
}
else
{
g_set_error (error,
G_IO_ERROR,
G_IO_ERROR_FAILED,
"Unexpected line '%s' while in WaitingForData state",
line);
g_free (line);
}
goto out;
case SERVER_STATE_WAITING_FOR_BEGIN:
debug_print ("SERVER: WaitingForBegin");
line = _my_g_input_stream_read_line_safe (g_io_stream_get_input_stream (auth->priv->stream),
&line_length,
cancellable,
error);
if (line == NULL)
goto out;
debug_print ("SERVER: WaitingForBegin, read '%s'", line);
if (g_strcmp0 (line, "BEGIN") == 0)
{
/* YAY, done! */
ret = TRUE;
g_free (line);
goto out;
}
else if (g_strcmp0 (line, "NEGOTIATE_UNIX_FD") == 0)
{
g_free (line);
if (offered_capabilities & G_DBUS_CAPABILITY_FLAGS_UNIX_FD_PASSING)
{
negotiated_capabilities |= G_DBUS_CAPABILITY_FLAGS_UNIX_FD_PASSING;
s = "AGREE_UNIX_FD\r\n";
debug_print ("SERVER: writing '%s'", s);
if (!g_data_output_stream_put_string (dos, s, cancellable, error))
goto out;
}
else
{
s = "ERROR \"fd passing not offered\"\r\n";
debug_print ("SERVER: writing '%s'", s);
if (!g_data_output_stream_put_string (dos, s, cancellable, error))
goto out;
}
}
else
{
g_debug ("Unexpected line '%s' while in WaitingForBegin state", line);
g_free (line);
s = "ERROR \"Unknown Command\"\r\n";
debug_print ("SERVER: writing '%s'", s);
if (!g_data_output_stream_put_string (dos, s, cancellable, error))
goto out;
}
break;
default:
g_assert_not_reached ();
break;
}
}
g_set_error_literal (error,
G_IO_ERROR,
G_IO_ERROR_FAILED,
"Not implemented (server)");
out:
g_clear_object (&mech);
g_clear_object (&dos);
g_clear_object (&own_credentials);
/* ensure return value is FALSE if error is set */
if (error != NULL && *error != NULL)
{
ret = FALSE;
}
if (ret)
{
if (out_negotiated_capabilities != NULL)
*out_negotiated_capabilities = negotiated_capabilities;
if (out_received_credentials != NULL)
*out_received_credentials = credentials != NULL ? g_object_ref (credentials) : NULL;
}
if (credentials != NULL)
g_object_unref (credentials);
debug_print ("SERVER: Done, authenticated=%d", ret);
return ret;
}
/* ---------------------------------------------------------------------------------------------------- */
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