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dbus/dbus/dbus-auth.c
Marc-André Lureau cfdfac9169 auth: fix a no-memory case 
Jumping to "out" will call _dbus_string_zero() unconditionally on tmp
string variables. Do not attempt to zero what wasn't even initialized.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
2022-01-21 16:05:09 +04:00

2954 lines
81 KiB
C
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/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
/* dbus-auth.c Authentication
*
* Copyright (C) 2002, 2003, 2004 Red Hat Inc.
*
* Licensed under the Academic Free License version 2.1
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*
*/
#include <config.h>
#include "dbus-auth.h"
#include "dbus-string.h"
#include "dbus-list.h"
#include "dbus-internals.h"
#include "dbus-keyring.h"
#include "dbus-sha.h"
#include "dbus-protocol.h"
#include "dbus-credentials.h"
/**
* @defgroup DBusAuth Authentication
* @ingroup DBusInternals
* @brief DBusAuth object
*
* DBusAuth manages the authentication negotiation when a connection
* is first established, and also manages any encryption used over a
* connection.
*
* @todo some SASL profiles require sending the empty string as a
* challenge/response, but we don't currently allow that in our
* protocol.
*
* @todo right now sometimes both ends will block waiting for input
* from the other end, e.g. if there's an error during
* DBUS_COOKIE_SHA1.
*
* @todo the cookie keyring needs to be cached globally not just
* per-auth (which raises threadsafety issues too)
*
* @todo grep FIXME in dbus-auth.c
*/
/**
* @defgroup DBusAuthInternals Authentication implementation details
* @ingroup DBusInternals
* @brief DBusAuth implementation details
*
* Private details of authentication code.
*
* @{
*/
/**
* This function appends an initial client response to the given string
*/
typedef dbus_bool_t (* DBusInitialResponseFunction) (DBusAuth *auth,
DBusString *response);
/**
* This function processes a block of data received from the peer.
* i.e. handles a DATA command.
*/
typedef dbus_bool_t (* DBusAuthDataFunction) (DBusAuth *auth,
const DBusString *data);
/**
* This function encodes a block of data from the peer.
*/
typedef dbus_bool_t (* DBusAuthEncodeFunction) (DBusAuth *auth,
const DBusString *data,
DBusString *encoded);
/**
* This function decodes a block of data from the peer.
*/
typedef dbus_bool_t (* DBusAuthDecodeFunction) (DBusAuth *auth,
const DBusString *data,
DBusString *decoded);
/**
* This function is called when the mechanism is abandoned.
*/
typedef void (* DBusAuthShutdownFunction) (DBusAuth *auth);
/**
* Virtual table representing a particular auth mechanism.
*/
typedef struct
{
const char *mechanism; /**< Name of the mechanism */
DBusAuthDataFunction server_data_func; /**< Function on server side for DATA */
DBusAuthEncodeFunction server_encode_func; /**< Function on server side to encode */
DBusAuthDecodeFunction server_decode_func; /**< Function on server side to decode */
DBusAuthShutdownFunction server_shutdown_func; /**< Function on server side to shut down */
DBusInitialResponseFunction client_initial_response_func; /**< Function on client side to handle initial response */
DBusAuthDataFunction client_data_func; /**< Function on client side for DATA */
DBusAuthEncodeFunction client_encode_func; /**< Function on client side for encode */
DBusAuthDecodeFunction client_decode_func; /**< Function on client side for decode */
DBusAuthShutdownFunction client_shutdown_func; /**< Function on client side for shutdown */
} DBusAuthMechanismHandler;
/**
* Enumeration for the known authentication commands.
*/
typedef enum {
DBUS_AUTH_COMMAND_AUTH,
DBUS_AUTH_COMMAND_CANCEL,
DBUS_AUTH_COMMAND_DATA,
DBUS_AUTH_COMMAND_BEGIN,
DBUS_AUTH_COMMAND_REJECTED,
DBUS_AUTH_COMMAND_OK,
DBUS_AUTH_COMMAND_ERROR,
DBUS_AUTH_COMMAND_UNKNOWN,
DBUS_AUTH_COMMAND_NEGOTIATE_UNIX_FD,
DBUS_AUTH_COMMAND_AGREE_UNIX_FD
} DBusAuthCommand;
/**
* Auth state function, determines the reaction to incoming events for
* a particular state. Returns whether we had enough memory to
* complete the operation.
*/
typedef dbus_bool_t (* DBusAuthStateFunction) (DBusAuth *auth,
DBusAuthCommand command,
const DBusString *args);
/**
* Information about a auth state.
*/
typedef struct
{
const char *name; /**< Name of the state */
DBusAuthStateFunction handler; /**< State function for this state */
} DBusAuthStateData;
/**
* Internal members of DBusAuth.
*/
struct DBusAuth
{
int refcount; /**< reference count */
const char *side; /**< Client or server */
DBusString incoming; /**< Incoming data buffer */
DBusString outgoing; /**< Outgoing data buffer */
const DBusAuthStateData *state; /**< Current protocol state */
const DBusAuthMechanismHandler *mech; /**< Current auth mechanism */
DBusString identity; /**< Current identity we're authorizing
* as.
*/
DBusCredentials *credentials; /**< Credentials read from socket
*/
DBusCredentials *authorized_identity; /**< Credentials that are authorized */
DBusCredentials *desired_identity; /**< Identity client has requested */
DBusString context; /**< Cookie scope */
DBusKeyring *keyring; /**< Keyring for cookie mechanism. */
int cookie_id; /**< ID of cookie to use */
DBusString challenge; /**< Challenge sent to client */
char **allowed_mechs; /**< Mechanisms we're allowed to use,
* or #NULL if we can use any
*/
unsigned int needed_memory : 1; /**< We needed memory to continue since last
* successful getting something done
*/
unsigned int already_got_mechanisms : 1; /**< Client already got mech list */
unsigned int already_asked_for_initial_response : 1; /**< Already sent a blank challenge to get an initial response */
unsigned int buffer_outstanding : 1; /**< Buffer is "checked out" for reading data into */
unsigned int unix_fd_possible : 1; /**< This side could do unix fd passing */
unsigned int unix_fd_negotiated : 1; /**< Unix fd was successfully negotiated */
};
/**
* "Subclass" of DBusAuth for client side
*/
typedef struct
{
DBusAuth base; /**< Parent class */
DBusList *mechs_to_try; /**< Mechanisms we got from the server that we're going to try using */
DBusString guid_from_server; /**< GUID received from server */
} DBusAuthClient;
/**
* "Subclass" of DBusAuth for server side.
*/
typedef struct
{
DBusAuth base; /**< Parent class */
int failures; /**< Number of times client has been rejected */
int max_failures; /**< Number of times we reject before disconnect */
DBusString guid; /**< Our globally unique ID in hex encoding */
} DBusAuthServer;
static void goto_state (DBusAuth *auth,
const DBusAuthStateData *new_state);
static dbus_bool_t send_auth (DBusAuth *auth,
const DBusAuthMechanismHandler *mech);
static dbus_bool_t send_data (DBusAuth *auth,
DBusString *data);
static dbus_bool_t send_rejected (DBusAuth *auth);
static dbus_bool_t send_error (DBusAuth *auth,
const char *message);
static dbus_bool_t send_ok (DBusAuth *auth);
static dbus_bool_t send_begin (DBusAuth *auth);
static dbus_bool_t send_cancel (DBusAuth *auth);
static dbus_bool_t send_negotiate_unix_fd (DBusAuth *auth);
static dbus_bool_t send_agree_unix_fd (DBusAuth *auth);
/**
* Client states
*/
static dbus_bool_t handle_server_state_waiting_for_auth (DBusAuth *auth,
DBusAuthCommand command,
const DBusString *args);
static dbus_bool_t handle_server_state_waiting_for_data (DBusAuth *auth,
DBusAuthCommand command,
const DBusString *args);
static dbus_bool_t handle_server_state_waiting_for_begin (DBusAuth *auth,
DBusAuthCommand command,
const DBusString *args);
static const DBusAuthStateData server_state_waiting_for_auth = {
"WaitingForAuth", handle_server_state_waiting_for_auth
};
static const DBusAuthStateData server_state_waiting_for_data = {
"WaitingForData", handle_server_state_waiting_for_data
};
static const DBusAuthStateData server_state_waiting_for_begin = {
"WaitingForBegin", handle_server_state_waiting_for_begin
};
/**
* Client states
*/
static dbus_bool_t handle_client_state_waiting_for_data (DBusAuth *auth,
DBusAuthCommand command,
const DBusString *args);
static dbus_bool_t handle_client_state_waiting_for_ok (DBusAuth *auth,
DBusAuthCommand command,
const DBusString *args);
static dbus_bool_t handle_client_state_waiting_for_reject (DBusAuth *auth,
DBusAuthCommand command,
const DBusString *args);
static dbus_bool_t handle_client_state_waiting_for_agree_unix_fd (DBusAuth *auth,
DBusAuthCommand command,
const DBusString *args);
static const DBusAuthStateData client_state_need_send_auth = {
"NeedSendAuth", NULL
};
static const DBusAuthStateData client_state_waiting_for_data = {
"WaitingForData", handle_client_state_waiting_for_data
};
/* The WaitingForOK state doesn't appear to be used.
* See https://bugs.freedesktop.org/show_bug.cgi?id=97298 */
_DBUS_GNUC_UNUSED
static const DBusAuthStateData client_state_waiting_for_ok = {
"WaitingForOK", handle_client_state_waiting_for_ok
};
static const DBusAuthStateData client_state_waiting_for_reject = {
"WaitingForReject", handle_client_state_waiting_for_reject
};
static const DBusAuthStateData client_state_waiting_for_agree_unix_fd = {
"WaitingForAgreeUnixFD", handle_client_state_waiting_for_agree_unix_fd
};
/**
* Common terminal states. Terminal states have handler == NULL.
*/
static const DBusAuthStateData common_state_authenticated = {
"Authenticated", NULL
};
static const DBusAuthStateData common_state_need_disconnect = {
"NeedDisconnect", NULL
};
static const char auth_side_client[] = "client";
static const char auth_side_server[] = "server";
/**
* @param auth the auth conversation
* @returns #TRUE if the conversation is the server side
*/
#define DBUS_AUTH_IS_SERVER(auth) ((auth)->side == auth_side_server)
/**
* @param auth the auth conversation
* @returns #TRUE if the conversation is the client side
*/
#define DBUS_AUTH_IS_CLIENT(auth) ((auth)->side == auth_side_client)
/**
* @param auth the auth conversation
* @returns auth cast to DBusAuthClient
*/
#define DBUS_AUTH_CLIENT(auth) ((DBusAuthClient*)(auth))
/**
* @param auth the auth conversation
* @returns auth cast to DBusAuthServer
*/
#define DBUS_AUTH_SERVER(auth) ((DBusAuthServer*)(auth))
/**
* The name of the auth ("client" or "server")
* @param auth the auth conversation
* @returns a string
*/
#define DBUS_AUTH_NAME(auth) ((auth)->side)
static DBusAuth*
_dbus_auth_new (int size)
{
DBusAuth *auth;
auth = dbus_malloc0 (size);
if (auth == NULL)
return NULL;
auth->refcount = 1;
auth->keyring = NULL;
auth->cookie_id = -1;
/* note that we don't use the max string length feature,
* because you can't use that feature if you're going to
* try to recover from out-of-memory (it creates
* what looks like unrecoverable inability to alloc
* more space in the string). But we do handle
* overlong buffers in _dbus_auth_do_work().
*/
if (!_dbus_string_init (&auth->incoming))
goto enomem_0;
if (!_dbus_string_init (&auth->outgoing))
goto enomem_1;
if (!_dbus_string_init (&auth->identity))
goto enomem_2;
if (!_dbus_string_init (&auth->context))
goto enomem_3;
if (!_dbus_string_init (&auth->challenge))
goto enomem_4;
/* default context if none is specified */
if (!_dbus_string_append (&auth->context, "org_freedesktop_general"))
goto enomem_5;
auth->credentials = _dbus_credentials_new ();
if (auth->credentials == NULL)
goto enomem_6;
auth->authorized_identity = _dbus_credentials_new ();
if (auth->authorized_identity == NULL)
goto enomem_7;
auth->desired_identity = _dbus_credentials_new ();
if (auth->desired_identity == NULL)
goto enomem_8;
return auth;
#if 0
enomem_9:
_dbus_credentials_unref (auth->desired_identity);
#endif
enomem_8:
_dbus_credentials_unref (auth->authorized_identity);
enomem_7:
_dbus_credentials_unref (auth->credentials);
enomem_6:
/* last alloc was an append to context, which is freed already below */ ;
enomem_5:
_dbus_string_free (&auth->challenge);
enomem_4:
_dbus_string_free (&auth->context);
enomem_3:
_dbus_string_free (&auth->identity);
enomem_2:
_dbus_string_free (&auth->outgoing);
enomem_1:
_dbus_string_free (&auth->incoming);
enomem_0:
dbus_free (auth);
return NULL;
}
static void
shutdown_mech (DBusAuth *auth)
{
/* Cancel any auth */
auth->already_asked_for_initial_response = FALSE;
_dbus_string_set_length (&auth->identity, 0);
_dbus_credentials_clear (auth->authorized_identity);
_dbus_credentials_clear (auth->desired_identity);
if (auth->mech != NULL)
{
_dbus_verbose ("%s: Shutting down mechanism %s\n",
DBUS_AUTH_NAME (auth), auth->mech->mechanism);
if (DBUS_AUTH_IS_CLIENT (auth))
(* auth->mech->client_shutdown_func) (auth);
else
(* auth->mech->server_shutdown_func) (auth);
auth->mech = NULL;
}
}
/*
* DBUS_COOKIE_SHA1 mechanism
*/
/* Returns TRUE but with an empty string hash if the
* cookie_id isn't known. As with all this code
* TRUE just means we had enough memory.
*/
static dbus_bool_t
sha1_compute_hash (DBusAuth *auth,
int cookie_id,
const DBusString *server_challenge,
const DBusString *client_challenge,
DBusString *hash)
{
DBusString cookie;
DBusString to_hash;
dbus_bool_t retval;
_dbus_assert (auth->keyring != NULL);
retval = FALSE;
if (!_dbus_string_init (&cookie))
return FALSE;
if (!_dbus_keyring_get_hex_key (auth->keyring, cookie_id,
&cookie))
goto out_0;
if (_dbus_string_get_length (&cookie) == 0)
{
retval = TRUE;
goto out_0;
}
if (!_dbus_string_init (&to_hash))
goto out_0;
if (!_dbus_string_copy (server_challenge, 0,
&to_hash, _dbus_string_get_length (&to_hash)))
goto out_1;
if (!_dbus_string_append (&to_hash, ":"))
goto out_1;
if (!_dbus_string_copy (client_challenge, 0,
&to_hash, _dbus_string_get_length (&to_hash)))
goto out_1;
if (!_dbus_string_append (&to_hash, ":"))
goto out_1;
if (!_dbus_string_copy (&cookie, 0,
&to_hash, _dbus_string_get_length (&to_hash)))
goto out_1;
if (!_dbus_sha_compute (&to_hash, hash))
goto out_1;
retval = TRUE;
out_1:
_dbus_string_zero (&to_hash);
_dbus_string_free (&to_hash);
out_0:
_dbus_string_zero (&cookie);
_dbus_string_free (&cookie);
return retval;
}
/** http://www.ietf.org/rfc/rfc2831.txt suggests at least 64 bits of
* entropy, we use 128. This is the number of bytes in the random
* challenge.
*/
#define N_CHALLENGE_BYTES (128/8)
static dbus_bool_t
sha1_handle_first_client_response (DBusAuth *auth,
const DBusString *data)
{
/* We haven't sent a challenge yet, we're expecting a desired
* username from the client.
*/
DBusString tmp = _DBUS_STRING_INIT_INVALID;
DBusString tmp2 = _DBUS_STRING_INIT_INVALID;
dbus_bool_t retval = FALSE;
DBusError error = DBUS_ERROR_INIT;
DBusCredentials *myself = NULL;
_dbus_string_set_length (&auth->challenge, 0);
if (_dbus_string_get_length (data) > 0)
{
if (_dbus_string_get_length (&auth->identity) > 0)
{
/* Tried to send two auth identities, wtf */
_dbus_verbose ("%s: client tried to send auth identity, but we already have one\n",
DBUS_AUTH_NAME (auth));
return send_rejected (auth);
}
else
{
/* this is our auth identity */
if (!_dbus_string_copy (data, 0, &auth->identity, 0))
return FALSE;
}
}
if (!_dbus_credentials_add_from_user (auth->desired_identity, data,
DBUS_CREDENTIALS_ADD_FLAGS_USER_DATABASE,
&error))
{
if (dbus_error_has_name (&error, DBUS_ERROR_NO_MEMORY))
{
dbus_error_free (&error);
return FALSE;
}
_dbus_verbose ("%s: Did not get a valid username from client: %s\n",
DBUS_AUTH_NAME (auth), error.message);
dbus_error_free (&error);
return send_rejected (auth);
}
if (!_dbus_string_init (&tmp))
return FALSE;
if (!_dbus_string_init (&tmp2))
{
_dbus_string_free (&tmp);
return FALSE;
}
myself = _dbus_credentials_new_from_current_process ();
if (myself == NULL)
goto out;
if (!_dbus_credentials_same_user (myself, auth->desired_identity))
{
/*
* DBUS_COOKIE_SHA1 is not suitable for authenticating that the
* client is anyone other than the user owning the process
* containing the DBusServer: we probably aren't allowed to write
* to other users' home directories. Even if we can (for example
* uid 0 on traditional Unix or CAP_DAC_OVERRIDE on Linux), we
* must not, because the other user controls their home directory,
* and could carry out symlink attacks to make us read from or
* write to unintended locations. It's difficult to avoid symlink
* attacks in a portable way, so we just don't try. This isn't a
* regression, because DBUS_COOKIE_SHA1 never worked for other
* users anyway.
*/
_dbus_verbose ("%s: client tried to authenticate as \"%s\", "
"but that doesn't match this process",
DBUS_AUTH_NAME (auth),
_dbus_string_get_const_data (data));
retval = send_rejected (auth);
goto out;
}
/* we cache the keyring for speed, so here we drop it if it's the
* wrong one. FIXME caching the keyring here is useless since we use
* a different DBusAuth for every connection.
*/
if (auth->keyring &&
!_dbus_keyring_is_for_credentials (auth->keyring,
auth->desired_identity))
{
_dbus_keyring_unref (auth->keyring);
auth->keyring = NULL;
}
if (auth->keyring == NULL)
{
auth->keyring = _dbus_keyring_new_for_credentials (auth->desired_identity,
&auth->context,
&error);
if (auth->keyring == NULL)
{
if (dbus_error_has_name (&error,
DBUS_ERROR_NO_MEMORY))
{
dbus_error_free (&error);
goto out;
}
else
{
_DBUS_ASSERT_ERROR_IS_SET (&error);
_dbus_verbose ("%s: Error loading keyring: %s\n",
DBUS_AUTH_NAME (auth), error.message);
if (send_rejected (auth))
retval = TRUE; /* retval is only about mem */
dbus_error_free (&error);
goto out;
}
}
else
{
_dbus_assert (!dbus_error_is_set (&error));
}
}
_dbus_assert (auth->keyring != NULL);
auth->cookie_id = _dbus_keyring_get_best_key (auth->keyring, &error);
if (auth->cookie_id < 0)
{
_DBUS_ASSERT_ERROR_IS_SET (&error);
_dbus_verbose ("%s: Could not get a cookie ID to send to client: %s\n",
DBUS_AUTH_NAME (auth), error.message);
if (send_rejected (auth))
retval = TRUE;
dbus_error_free (&error);
goto out;
}
else
{
_dbus_assert (!dbus_error_is_set (&error));
}
if (!_dbus_string_copy (&auth->context, 0,
&tmp2, _dbus_string_get_length (&tmp2)))
goto out;
if (!_dbus_string_append (&tmp2, " "))
goto out;
if (!_dbus_string_append_int (&tmp2, auth->cookie_id))
goto out;
if (!_dbus_string_append (&tmp2, " "))
goto out;
if (!_dbus_generate_random_bytes (&tmp, N_CHALLENGE_BYTES, &error))
{
if (dbus_error_has_name (&error, DBUS_ERROR_NO_MEMORY))
{
dbus_error_free (&error);
goto out;
}
else
{
_DBUS_ASSERT_ERROR_IS_SET (&error);
_dbus_verbose ("%s: Error generating challenge: %s\n",
DBUS_AUTH_NAME (auth), error.message);
if (send_rejected (auth))
retval = TRUE; /* retval is only about mem */
dbus_error_free (&error);
goto out;
}
}
_dbus_string_set_length (&auth->challenge, 0);
if (!_dbus_string_hex_encode (&tmp, 0, &auth->challenge, 0))
goto out;
if (!_dbus_string_hex_encode (&tmp, 0, &tmp2,
_dbus_string_get_length (&tmp2)))
goto out;
if (!send_data (auth, &tmp2))
goto out;
goto_state (auth, &server_state_waiting_for_data);
retval = TRUE;
out:
_dbus_string_zero (&tmp);
_dbus_string_free (&tmp);
_dbus_string_zero (&tmp2);
_dbus_string_free (&tmp2);
_dbus_clear_credentials (&myself);
return retval;
}
static dbus_bool_t
sha1_handle_second_client_response (DBusAuth *auth,
const DBusString *data)
{
/* We are expecting a response which is the hex-encoded client
* challenge, space, then SHA-1 hash of the concatenation of our
* challenge, ":", client challenge, ":", secret key, all
* hex-encoded.
*/
int i;
DBusString client_challenge;
DBusString client_hash;
dbus_bool_t retval;
DBusString correct_hash;
retval = FALSE;
if (!_dbus_string_find_blank (data, 0, &i))
{
_dbus_verbose ("%s: no space separator in client response\n",
DBUS_AUTH_NAME (auth));
return send_rejected (auth);
}
if (!_dbus_string_init (&client_challenge))
goto out_0;
if (!_dbus_string_init (&client_hash))
goto out_1;
if (!_dbus_string_copy_len (data, 0, i, &client_challenge,
0))
goto out_2;
_dbus_string_skip_blank (data, i, &i);
if (!_dbus_string_copy_len (data, i,
_dbus_string_get_length (data) - i,
&client_hash,
0))
goto out_2;
if (_dbus_string_get_length (&client_challenge) == 0 ||
_dbus_string_get_length (&client_hash) == 0)
{
_dbus_verbose ("%s: zero-length client challenge or hash\n",
DBUS_AUTH_NAME (auth));
if (send_rejected (auth))
retval = TRUE;
goto out_2;
}
if (!_dbus_string_init (&correct_hash))
goto out_2;
if (!sha1_compute_hash (auth, auth->cookie_id,
&auth->challenge,
&client_challenge,
&correct_hash))
goto out_3;
/* if cookie_id was invalid, then we get an empty hash */
if (_dbus_string_get_length (&correct_hash) == 0)
{
if (send_rejected (auth))
retval = TRUE;
goto out_3;
}
if (!_dbus_string_equal (&client_hash, &correct_hash))
{
if (send_rejected (auth))
retval = TRUE;
goto out_3;
}
if (!_dbus_credentials_add_credentials (auth->authorized_identity,
auth->desired_identity))
goto out_3;
/* Copy process ID from the socket credentials if it's there
*/
if (!_dbus_credentials_add_credential (auth->authorized_identity,
DBUS_CREDENTIAL_UNIX_PROCESS_ID,
auth->credentials))
goto out_3;
if (!send_ok (auth))
goto out_3;
_dbus_verbose ("%s: authenticated client using DBUS_COOKIE_SHA1\n",
DBUS_AUTH_NAME (auth));
retval = TRUE;
out_3:
_dbus_string_zero (&correct_hash);
_dbus_string_free (&correct_hash);
out_2:
_dbus_string_zero (&client_hash);
_dbus_string_free (&client_hash);
out_1:
_dbus_string_free (&client_challenge);
out_0:
return retval;
}
static dbus_bool_t
handle_server_data_cookie_sha1_mech (DBusAuth *auth,
const DBusString *data)
{
if (auth->cookie_id < 0)
return sha1_handle_first_client_response (auth, data);
else
return sha1_handle_second_client_response (auth, data);
}
static void
handle_server_shutdown_cookie_sha1_mech (DBusAuth *auth)
{
auth->cookie_id = -1;
_dbus_string_set_length (&auth->challenge, 0);
}
static dbus_bool_t
handle_client_initial_response_cookie_sha1_mech (DBusAuth *auth,
DBusString *response)
{
DBusString username;
dbus_bool_t retval;
retval = FALSE;
if (!_dbus_string_init (&username))
return FALSE;
if (!_dbus_append_user_from_current_process (&username))
goto out_0;
if (!_dbus_string_hex_encode (&username, 0,
response,
_dbus_string_get_length (response)))
goto out_0;
retval = TRUE;
out_0:
_dbus_string_free (&username);
return retval;
}
static dbus_bool_t
handle_client_data_cookie_sha1_mech (DBusAuth *auth,
const DBusString *data)
{
/* The data we get from the server should be the cookie context
* name, the cookie ID, and the server challenge, separated by
* spaces. We send back our challenge string and the correct hash.
*/
dbus_bool_t retval = FALSE;
DBusString context;
DBusString cookie_id_str;
DBusString server_challenge;
DBusString client_challenge;
DBusString correct_hash;
DBusString tmp;
int i, j;
long val;
DBusError error = DBUS_ERROR_INIT;
if (!_dbus_string_find_blank (data, 0, &i))
{
if (send_error (auth,
"Server did not send context/ID/challenge properly"))
retval = TRUE;
goto out_0;
}
if (!_dbus_string_init (&context))
goto out_0;
if (!_dbus_string_copy_len (data, 0, i,
&context, 0))
goto out_1;
_dbus_string_skip_blank (data, i, &i);
if (!_dbus_string_find_blank (data, i, &j))
{
if (send_error (auth,
"Server did not send context/ID/challenge properly"))
retval = TRUE;
goto out_1;
}
if (!_dbus_string_init (&cookie_id_str))
goto out_1;
if (!_dbus_string_copy_len (data, i, j - i,
&cookie_id_str, 0))
goto out_2;
if (!_dbus_string_init (&server_challenge))
goto out_2;
i = j;
_dbus_string_skip_blank (data, i, &i);
j = _dbus_string_get_length (data);
if (!_dbus_string_copy_len (data, i, j - i,
&server_challenge, 0))
goto out_3;
if (!_dbus_keyring_validate_context (&context))
{
if (send_error (auth, "Server sent invalid cookie context"))
retval = TRUE;
goto out_3;
}
if (!_dbus_string_parse_int (&cookie_id_str, 0, &val, NULL))
{
if (send_error (auth, "Could not parse cookie ID as an integer"))
retval = TRUE;
goto out_3;
}
if (_dbus_string_get_length (&server_challenge) == 0)
{
if (send_error (auth, "Empty server challenge string"))
retval = TRUE;
goto out_3;
}
if (auth->keyring == NULL)
{
auth->keyring = _dbus_keyring_new_for_credentials (NULL,
&context,
&error);
if (auth->keyring == NULL)
{
if (dbus_error_has_name (&error,
DBUS_ERROR_NO_MEMORY))
{
dbus_error_free (&error);
goto out_3;
}
else
{
_DBUS_ASSERT_ERROR_IS_SET (&error);
_dbus_verbose ("%s: Error loading keyring: %s\n",
DBUS_AUTH_NAME (auth), error.message);
if (send_error (auth, "Could not load cookie file"))
retval = TRUE; /* retval is only about mem */
dbus_error_free (&error);
goto out_3;
}
}
else
{
_dbus_assert (!dbus_error_is_set (&error));
}
}
_dbus_assert (auth->keyring != NULL);
if (!_dbus_string_init (&tmp))
goto out_3;
if (!_dbus_generate_random_bytes (&tmp, N_CHALLENGE_BYTES, &error))
{
if (dbus_error_has_name (&error, DBUS_ERROR_NO_MEMORY))
{
dbus_error_free (&error);
goto out_4;
}
else
{
_DBUS_ASSERT_ERROR_IS_SET (&error);
_dbus_verbose ("%s: Failed to generate challenge: %s\n",
DBUS_AUTH_NAME (auth), error.message);
if (send_error (auth, "Failed to generate challenge"))
retval = TRUE; /* retval is only about mem */
dbus_error_free (&error);
goto out_4;
}
}
if (!_dbus_string_init (&client_challenge))
goto out_4;
if (!_dbus_string_hex_encode (&tmp, 0, &client_challenge, 0))
goto out_5;
if (!_dbus_string_init (&correct_hash))
goto out_5;
if (!sha1_compute_hash (auth, val,
&server_challenge,
&client_challenge,
&correct_hash))
goto out_6;
if (_dbus_string_get_length (&correct_hash) == 0)
{
/* couldn't find the cookie ID or something */
if (send_error (auth, "Don't have the requested cookie ID"))
retval = TRUE;
goto out_6;
}
_dbus_string_set_length (&tmp, 0);
if (!_dbus_string_copy (&client_challenge, 0, &tmp,
_dbus_string_get_length (&tmp)))
goto out_6;
if (!_dbus_string_append (&tmp, " "))
goto out_6;
if (!_dbus_string_copy (&correct_hash, 0, &tmp,
_dbus_string_get_length (&tmp)))
goto out_6;
if (!send_data (auth, &tmp))
goto out_6;
retval = TRUE;
out_6:
_dbus_string_zero (&correct_hash);
_dbus_string_free (&correct_hash);
out_5:
_dbus_string_free (&client_challenge);
out_4:
_dbus_string_zero (&tmp);
_dbus_string_free (&tmp);
out_3:
_dbus_string_free (&server_challenge);
out_2:
_dbus_string_free (&cookie_id_str);
out_1:
_dbus_string_free (&context);
out_0:
return retval;
}
static void
handle_client_shutdown_cookie_sha1_mech (DBusAuth *auth)
{
auth->cookie_id = -1;
_dbus_string_set_length (&auth->challenge, 0);
}
/*
* EXTERNAL mechanism
*/
static dbus_bool_t
handle_server_data_external_mech (DBusAuth *auth,
const DBusString *data)
{
if (_dbus_credentials_are_anonymous (auth->credentials))
{
_dbus_verbose ("%s: no credentials, mechanism EXTERNAL can't authenticate\n",
DBUS_AUTH_NAME (auth));
return send_rejected (auth);
}
if (_dbus_string_get_length (data) > 0)
{
if (_dbus_string_get_length (&auth->identity) > 0)
{
/* Tried to send two auth identities, wtf */
_dbus_verbose ("%s: client tried to send auth identity, but we already have one\n",
DBUS_AUTH_NAME (auth));
return send_rejected (auth);
}
else
{
/* this is our auth identity */
if (!_dbus_string_copy (data, 0, &auth->identity, 0))
return FALSE;
}
}
/* Poke client for an auth identity, if none given */
if (_dbus_string_get_length (&auth->identity) == 0 &&
!auth->already_asked_for_initial_response)
{
if (send_data (auth, NULL))
{
_dbus_verbose ("%s: sending empty challenge asking client for auth identity\n",
DBUS_AUTH_NAME (auth));
auth->already_asked_for_initial_response = TRUE;
goto_state (auth, &server_state_waiting_for_data);
return TRUE;
}
else
return FALSE;
}
_dbus_credentials_clear (auth->desired_identity);
/* If auth->identity is still empty here, then client
* responded with an empty string after we poked it for
* an initial response. This means to try to auth the
* identity provided in the credentials.
*/
if (_dbus_string_get_length (&auth->identity) == 0)
{
if (!_dbus_credentials_add_credentials (auth->desired_identity,
auth->credentials))
{
return FALSE; /* OOM */
}
}
else
{
DBusError error = DBUS_ERROR_INIT;
if (!_dbus_credentials_add_from_user (auth->desired_identity,
&auth->identity,
DBUS_CREDENTIALS_ADD_FLAGS_NONE,
&error))
{
if (dbus_error_has_name (&error, DBUS_ERROR_NO_MEMORY))
{
dbus_error_free (&error);
return FALSE;
}
_dbus_verbose ("%s: could not get credentials from uid string: %s\n",
DBUS_AUTH_NAME (auth), error.message);
dbus_error_free (&error);
return send_rejected (auth);
}
}
if (_dbus_credentials_are_anonymous (auth->desired_identity))
{
_dbus_verbose ("%s: desired user %s is no good\n",
DBUS_AUTH_NAME (auth),
_dbus_string_get_const_data (&auth->identity));
return send_rejected (auth);
}
if (_dbus_credentials_are_superset (auth->credentials,
auth->desired_identity))
{
/* client has authenticated */
if (!_dbus_credentials_add_credentials (auth->authorized_identity,
auth->desired_identity))
return FALSE;
/* also copy misc process info from the socket credentials
*/
if (!_dbus_credentials_add_credential (auth->authorized_identity,
DBUS_CREDENTIAL_UNIX_PROCESS_ID,
auth->credentials))
return FALSE;
if (!_dbus_credentials_add_credential (auth->authorized_identity,
DBUS_CREDENTIAL_ADT_AUDIT_DATA_ID,
auth->credentials))
return FALSE;
if (!_dbus_credentials_add_credential (auth->authorized_identity,
DBUS_CREDENTIAL_UNIX_GROUP_IDS,
auth->credentials))
return FALSE;
if (!_dbus_credentials_add_credential (auth->authorized_identity,
DBUS_CREDENTIAL_LINUX_SECURITY_LABEL,
auth->credentials))
return FALSE;
if (!send_ok (auth))
return FALSE;
_dbus_verbose ("%s: authenticated client based on socket credentials\n",
DBUS_AUTH_NAME (auth));
return TRUE;
}
else
{
_dbus_verbose ("%s: desired identity not found in socket credentials\n",
DBUS_AUTH_NAME (auth));
return send_rejected (auth);
}
}
static void
handle_server_shutdown_external_mech (DBusAuth *auth)
{
}
static dbus_bool_t
handle_client_initial_response_external_mech (DBusAuth *auth,
DBusString *response)
{
/* We always append our UID as an initial response, so the server
* doesn't have to send back an empty challenge to check whether we
* want to specify an identity. i.e. this avoids a round trip that
* the spec for the EXTERNAL mechanism otherwise requires.
*/
DBusString plaintext;
if (!_dbus_string_init (&plaintext))
return FALSE;
if (!_dbus_append_user_from_current_process (&plaintext))
goto failed;
if (!_dbus_string_hex_encode (&plaintext, 0,
response,
_dbus_string_get_length (response)))
goto failed;
_dbus_string_free (&plaintext);
return TRUE;
failed:
_dbus_string_free (&plaintext);
return FALSE;
}
static dbus_bool_t
handle_client_data_external_mech (DBusAuth *auth,
const DBusString *data)
{
return TRUE;
}
static void
handle_client_shutdown_external_mech (DBusAuth *auth)
{
}
/*
* ANONYMOUS mechanism
*/
static dbus_bool_t
handle_server_data_anonymous_mech (DBusAuth *auth,
const DBusString *data)
{
if (_dbus_string_get_length (data) > 0)
{
/* Client is allowed to send "trace" data, the only defined
* meaning is that if it contains '@' it is an email address,
* and otherwise it is anything else, and it's supposed to be
* UTF-8
*/
if (!_dbus_string_validate_utf8 (data, 0, _dbus_string_get_length (data)))
{
_dbus_verbose ("%s: Received invalid UTF-8 trace data from ANONYMOUS client\n",
DBUS_AUTH_NAME (auth));
return send_rejected (auth);
}
_dbus_verbose ("%s: ANONYMOUS client sent trace string: '%s'\n",
DBUS_AUTH_NAME (auth),
_dbus_string_get_const_data (data));
}
/* We want to be anonymous (clear in case some other protocol got midway through I guess) */
_dbus_credentials_clear (auth->desired_identity);
/* Copy process ID from the socket credentials
*/
if (!_dbus_credentials_add_credential (auth->authorized_identity,
DBUS_CREDENTIAL_UNIX_PROCESS_ID,
auth->credentials))
return FALSE;
/* Anonymous is always allowed */
if (!send_ok (auth))
return FALSE;
_dbus_verbose ("%s: authenticated client as anonymous\n",
DBUS_AUTH_NAME (auth));
return TRUE;
}
static void
handle_server_shutdown_anonymous_mech (DBusAuth *auth)
{
}
static dbus_bool_t
handle_client_initial_response_anonymous_mech (DBusAuth *auth,
DBusString *response)
{
/* Our initial response is a "trace" string which must be valid UTF-8
* and must be an email address if it contains '@'.
* We just send the dbus implementation info, like a user-agent or
* something, because... why not. There's nothing guaranteed here
* though, we could change it later.
*/
DBusString plaintext;
if (!_dbus_string_init (&plaintext))
return FALSE;
if (!_dbus_string_append (&plaintext,
"libdbus " DBUS_VERSION_STRING))
goto failed;
if (!_dbus_string_hex_encode (&plaintext, 0,
response,
_dbus_string_get_length (response)))
goto failed;
_dbus_string_free (&plaintext);
return TRUE;
failed:
_dbus_string_free (&plaintext);
return FALSE;
}
static dbus_bool_t
handle_client_data_anonymous_mech (DBusAuth *auth,
const DBusString *data)
{
return TRUE;
}
static void
handle_client_shutdown_anonymous_mech (DBusAuth *auth)
{
}
/* Put mechanisms here in order of preference.
* Right now we have:
*
* - EXTERNAL checks socket credentials (or in the future, other info from the OS)
* - DBUS_COOKIE_SHA1 uses a cookie in the home directory, like xauth or ICE
* - ANONYMOUS checks nothing but doesn't auth the person as a user
*
* We might ideally add a mechanism to chain to Cyrus SASL so we can
* use its mechanisms as well.
*
*/
static const DBusAuthMechanismHandler
all_mechanisms[] = {
{ "EXTERNAL",
handle_server_data_external_mech,
NULL, NULL,
handle_server_shutdown_external_mech,
handle_client_initial_response_external_mech,
handle_client_data_external_mech,
NULL, NULL,
handle_client_shutdown_external_mech },
{ "DBUS_COOKIE_SHA1",
handle_server_data_cookie_sha1_mech,
NULL, NULL,
handle_server_shutdown_cookie_sha1_mech,
handle_client_initial_response_cookie_sha1_mech,
handle_client_data_cookie_sha1_mech,
NULL, NULL,
handle_client_shutdown_cookie_sha1_mech },
{ "ANONYMOUS",
handle_server_data_anonymous_mech,
NULL, NULL,
handle_server_shutdown_anonymous_mech,
handle_client_initial_response_anonymous_mech,
handle_client_data_anonymous_mech,
NULL, NULL,
handle_client_shutdown_anonymous_mech },
{ NULL, NULL }
};
static const DBusAuthMechanismHandler*
find_mech (const DBusString *name,
char **allowed_mechs)
{
int i;
if (allowed_mechs != NULL &&
!_dbus_string_array_contains ((const char**) allowed_mechs,
_dbus_string_get_const_data (name)))
return NULL;
i = 0;
while (all_mechanisms[i].mechanism != NULL)
{
if (_dbus_string_equal_c_str (name,
all_mechanisms[i].mechanism))
return &all_mechanisms[i];
++i;
}
return NULL;
}
static dbus_bool_t
send_auth (DBusAuth *auth, const DBusAuthMechanismHandler *mech)
{
DBusString auth_command;
if (!_dbus_string_init (&auth_command))
return FALSE;
if (!_dbus_string_append (&auth_command,
"AUTH "))
{
_dbus_string_free (&auth_command);
return FALSE;
}
if (!_dbus_string_append (&auth_command,
mech->mechanism))
{
_dbus_string_free (&auth_command);
return FALSE;
}
if (mech->client_initial_response_func != NULL)
{
if (!_dbus_string_append (&auth_command, " "))
{
_dbus_string_free (&auth_command);
return FALSE;
}
if (!(* mech->client_initial_response_func) (auth, &auth_command))
{
_dbus_string_free (&auth_command);
return FALSE;
}
}
if (!_dbus_string_append (&auth_command,
"\r\n"))
{
_dbus_string_free (&auth_command);
return FALSE;
}
if (!_dbus_string_copy (&auth_command, 0,
&auth->outgoing,
_dbus_string_get_length (&auth->outgoing)))
{
_dbus_string_free (&auth_command);
return FALSE;
}
_dbus_string_free (&auth_command);
shutdown_mech (auth);
auth->mech = mech;
goto_state (auth, &client_state_waiting_for_data);
return TRUE;
}
static dbus_bool_t
send_data (DBusAuth *auth, DBusString *data)
{
int old_len;
if (data == NULL || _dbus_string_get_length (data) == 0)
return _dbus_string_append (&auth->outgoing, "DATA\r\n");
else
{
old_len = _dbus_string_get_length (&auth->outgoing);
if (!_dbus_string_append (&auth->outgoing, "DATA "))
goto out;
if (!_dbus_string_hex_encode (data, 0, &auth->outgoing,
_dbus_string_get_length (&auth->outgoing)))
goto out;
if (!_dbus_string_append (&auth->outgoing, "\r\n"))
goto out;
return TRUE;
out:
_dbus_string_set_length (&auth->outgoing, old_len);
return FALSE;
}
}
static dbus_bool_t
send_rejected (DBusAuth *auth)
{
DBusString command;
DBusAuthServer *server_auth;
int i;
if (!_dbus_string_init (&command))
return FALSE;
if (!_dbus_string_append (&command,
"REJECTED"))
goto nomem;
for (i = 0; all_mechanisms[i].mechanism != NULL; i++)
{
/* skip mechanisms that aren't allowed */
if (auth->allowed_mechs != NULL &&
!_dbus_string_array_contains ((const char**)auth->allowed_mechs,
all_mechanisms[i].mechanism))
continue;
if (!_dbus_string_append (&command,
" "))
goto nomem;
if (!_dbus_string_append (&command,
all_mechanisms[i].mechanism))
goto nomem;
}
if (!_dbus_string_append (&command, "\r\n"))
goto nomem;
if (!_dbus_string_copy (&command, 0, &auth->outgoing,
_dbus_string_get_length (&auth->outgoing)))
goto nomem;
shutdown_mech (auth);
_dbus_assert (DBUS_AUTH_IS_SERVER (auth));
server_auth = DBUS_AUTH_SERVER (auth);
server_auth->failures += 1;
if (server_auth->failures >= server_auth->max_failures)
goto_state (auth, &common_state_need_disconnect);
else
goto_state (auth, &server_state_waiting_for_auth);
_dbus_string_free (&command);
return TRUE;
nomem:
_dbus_string_free (&command);
return FALSE;
}
static dbus_bool_t
send_error (DBusAuth *auth, const char *message)
{
return _dbus_string_append_printf (&auth->outgoing,
"ERROR \"%s\"\r\n", message);
}
static dbus_bool_t
send_ok (DBusAuth *auth)
{
int orig_len;
orig_len = _dbus_string_get_length (&auth->outgoing);
if (_dbus_string_append (&auth->outgoing, "OK ") &&
_dbus_string_copy (& DBUS_AUTH_SERVER (auth)->guid,
0,
&auth->outgoing,
_dbus_string_get_length (&auth->outgoing)) &&
_dbus_string_append (&auth->outgoing, "\r\n"))
{
goto_state (auth, &server_state_waiting_for_begin);
return TRUE;
}
else
{
_dbus_string_set_length (&auth->outgoing, orig_len);
return FALSE;
}
}
static dbus_bool_t
send_begin (DBusAuth *auth)
{
if (!_dbus_string_append (&auth->outgoing,
"BEGIN\r\n"))
return FALSE;
goto_state (auth, &common_state_authenticated);
return TRUE;
}
static dbus_bool_t
process_ok(DBusAuth *auth,
const DBusString *args_from_ok) {
int end_of_hex;
/* "args_from_ok" should be the GUID, whitespace already pulled off the front */
_dbus_assert (_dbus_string_get_length (& DBUS_AUTH_CLIENT (auth)->guid_from_server) == 0);
/* We decode the hex string to binary, using guid_from_server as scratch... */
end_of_hex = 0;
if (!_dbus_string_hex_decode (args_from_ok, 0, &end_of_hex,
& DBUS_AUTH_CLIENT (auth)->guid_from_server, 0))
return FALSE;
/* now clear out the scratch */
_dbus_string_set_length (& DBUS_AUTH_CLIENT (auth)->guid_from_server, 0);
if (end_of_hex != _dbus_string_get_length (args_from_ok) ||
end_of_hex == 0)
{
_dbus_verbose ("Bad GUID from server, parsed %d bytes and had %d bytes from server\n",
end_of_hex, _dbus_string_get_length (args_from_ok));
goto_state (auth, &common_state_need_disconnect);
return TRUE;
}
if (!_dbus_string_copy (args_from_ok, 0, &DBUS_AUTH_CLIENT (auth)->guid_from_server, 0)) {
_dbus_string_set_length (& DBUS_AUTH_CLIENT (auth)->guid_from_server, 0);
return FALSE;
}
_dbus_verbose ("Got GUID '%s' from the server\n",
_dbus_string_get_const_data (& DBUS_AUTH_CLIENT (auth)->guid_from_server));
if (auth->unix_fd_possible)
{
if (!send_negotiate_unix_fd (auth))
{
_dbus_string_set_length (& DBUS_AUTH_CLIENT (auth)->guid_from_server, 0);
return FALSE;
}
return TRUE;
}
_dbus_verbose("Not negotiating unix fd passing, since not possible\n");
if (!send_begin (auth))
{
_dbus_string_set_length (& DBUS_AUTH_CLIENT (auth)->guid_from_server, 0);
return FALSE;
}
return TRUE;
}
static dbus_bool_t
send_cancel (DBusAuth *auth)
{
if (_dbus_string_append (&auth->outgoing, "CANCEL\r\n"))
{
goto_state (auth, &client_state_waiting_for_reject);
return TRUE;
}
else
return FALSE;
}
static dbus_bool_t
process_data (DBusAuth *auth,
const DBusString *args,
DBusAuthDataFunction data_func)
{
int end;
DBusString decoded;
if (!_dbus_string_init (&decoded))
return FALSE;
if (!_dbus_string_hex_decode (args, 0, &end, &decoded, 0))
{
_dbus_string_free (&decoded);
return FALSE;
}
if (_dbus_string_get_length (args) != end)
{
_dbus_string_free (&decoded);
if (!send_error (auth, "Invalid hex encoding"))
return FALSE;
return TRUE;
}
#ifdef DBUS_ENABLE_VERBOSE_MODE
if (_dbus_string_validate_ascii (&decoded, 0,
_dbus_string_get_length (&decoded)))
_dbus_verbose ("%s: data: '%s'\n",
DBUS_AUTH_NAME (auth),
_dbus_string_get_const_data (&decoded));
#endif
if (!(* data_func) (auth, &decoded))
{
_dbus_string_free (&decoded);
return FALSE;
}
_dbus_string_free (&decoded);
return TRUE;
}
static dbus_bool_t
send_negotiate_unix_fd (DBusAuth *auth)
{
if (!_dbus_string_append (&auth->outgoing,
"NEGOTIATE_UNIX_FD\r\n"))
return FALSE;
goto_state (auth, &client_state_waiting_for_agree_unix_fd);
return TRUE;
}
static dbus_bool_t
send_agree_unix_fd (DBusAuth *auth)
{
_dbus_assert(auth->unix_fd_possible);
auth->unix_fd_negotiated = TRUE;
_dbus_verbose("Agreed to UNIX FD passing\n");
if (!_dbus_string_append (&auth->outgoing,
"AGREE_UNIX_FD\r\n"))
return FALSE;
goto_state (auth, &server_state_waiting_for_begin);
return TRUE;
}
static dbus_bool_t
handle_auth (DBusAuth *auth, const DBusString *args)
{
if (_dbus_string_get_length (args) == 0)
{
/* No args to the auth, send mechanisms */
if (!send_rejected (auth))
return FALSE;
return TRUE;
}
else
{
int i;
DBusString mech;
DBusString hex_response;
_dbus_string_find_blank (args, 0, &i);
if (!_dbus_string_init (&mech))
return FALSE;
if (!_dbus_string_init (&hex_response))
{
_dbus_string_free (&mech);
return FALSE;
}
if (!_dbus_string_copy_len (args, 0, i, &mech, 0))
goto failed;
_dbus_string_skip_blank (args, i, &i);
if (!_dbus_string_copy (args, i, &hex_response, 0))
goto failed;
auth->mech = find_mech (&mech, auth->allowed_mechs);
if (auth->mech != NULL)
{
_dbus_verbose ("%s: Trying mechanism %s\n",
DBUS_AUTH_NAME (auth),
auth->mech->mechanism);
if (!process_data (auth, &hex_response,
auth->mech->server_data_func))
goto failed;
}
else
{
/* Unsupported mechanism */
_dbus_verbose ("%s: Unsupported mechanism %s\n",
DBUS_AUTH_NAME (auth),
_dbus_string_get_const_data (&mech));
if (!send_rejected (auth))
goto failed;
}
_dbus_string_free (&mech);
_dbus_string_free (&hex_response);
return TRUE;
failed:
auth->mech = NULL;
_dbus_string_free (&mech);
_dbus_string_free (&hex_response);
return FALSE;
}
}
static dbus_bool_t
handle_server_state_waiting_for_auth (DBusAuth *auth,
DBusAuthCommand command,
const DBusString *args)
{
switch (command)
{
case DBUS_AUTH_COMMAND_AUTH:
return handle_auth (auth, args);
case DBUS_AUTH_COMMAND_CANCEL:
case DBUS_AUTH_COMMAND_DATA:
return send_error (auth, "Not currently in an auth conversation");
case DBUS_AUTH_COMMAND_BEGIN:
goto_state (auth, &common_state_need_disconnect);
return TRUE;
case DBUS_AUTH_COMMAND_ERROR:
return send_rejected (auth);
case DBUS_AUTH_COMMAND_NEGOTIATE_UNIX_FD:
return send_error (auth, "Need to authenticate first");
case DBUS_AUTH_COMMAND_REJECTED:
case DBUS_AUTH_COMMAND_OK:
case DBUS_AUTH_COMMAND_UNKNOWN:
case DBUS_AUTH_COMMAND_AGREE_UNIX_FD:
default:
return send_error (auth, "Unknown command");
}
}
static dbus_bool_t
handle_server_state_waiting_for_data (DBusAuth *auth,
DBusAuthCommand command,
const DBusString *args)
{
switch (command)
{
case DBUS_AUTH_COMMAND_AUTH:
return send_error (auth, "Sent AUTH while another AUTH in progress");
case DBUS_AUTH_COMMAND_CANCEL:
case DBUS_AUTH_COMMAND_ERROR:
return send_rejected (auth);
case DBUS_AUTH_COMMAND_DATA:
return process_data (auth, args, auth->mech->server_data_func);
case DBUS_AUTH_COMMAND_BEGIN:
goto_state (auth, &common_state_need_disconnect);
return TRUE;
case DBUS_AUTH_COMMAND_NEGOTIATE_UNIX_FD:
return send_error (auth, "Need to authenticate first");
case DBUS_AUTH_COMMAND_REJECTED:
case DBUS_AUTH_COMMAND_OK:
case DBUS_AUTH_COMMAND_UNKNOWN:
case DBUS_AUTH_COMMAND_AGREE_UNIX_FD:
default:
return send_error (auth, "Unknown command");
}
}
static dbus_bool_t
handle_server_state_waiting_for_begin (DBusAuth *auth,
DBusAuthCommand command,
const DBusString *args)
{
switch (command)
{
case DBUS_AUTH_COMMAND_AUTH:
return send_error (auth, "Sent AUTH while expecting BEGIN");
case DBUS_AUTH_COMMAND_DATA:
return send_error (auth, "Sent DATA while expecting BEGIN");
case DBUS_AUTH_COMMAND_BEGIN:
goto_state (auth, &common_state_authenticated);
return TRUE;
case DBUS_AUTH_COMMAND_NEGOTIATE_UNIX_FD:
if (auth->unix_fd_possible)
return send_agree_unix_fd(auth);
else
return send_error(auth, "Unix FD passing not supported, not authenticated or otherwise not possible");
case DBUS_AUTH_COMMAND_REJECTED:
case DBUS_AUTH_COMMAND_OK:
case DBUS_AUTH_COMMAND_UNKNOWN:
case DBUS_AUTH_COMMAND_AGREE_UNIX_FD:
default:
return send_error (auth, "Unknown command");
case DBUS_AUTH_COMMAND_CANCEL:
case DBUS_AUTH_COMMAND_ERROR:
return send_rejected (auth);
}
}
/* return FALSE if no memory, TRUE if all OK */
static dbus_bool_t
get_word (const DBusString *str,
int *start,
DBusString *word)
{
int i;
_dbus_string_skip_blank (str, *start, start);
_dbus_string_find_blank (str, *start, &i);
if (i > *start)
{
if (!_dbus_string_copy_len (str, *start, i - *start, word, 0))
return FALSE;
*start = i;
}
return TRUE;
}
static dbus_bool_t
record_mechanisms (DBusAuth *auth,
const DBusString *args)
{
int next;
int len;
if (auth->already_got_mechanisms)
return TRUE;
len = _dbus_string_get_length (args);
next = 0;
while (next < len)
{
DBusString m;
const DBusAuthMechanismHandler *mech;
if (!_dbus_string_init (&m))
goto nomem;
if (!get_word (args, &next, &m))
{
_dbus_string_free (&m);
goto nomem;
}
mech = find_mech (&m, auth->allowed_mechs);
if (mech != NULL)
{
/* FIXME right now we try mechanisms in the order
* the server lists them; should we do them in
* some more deterministic order?
*
* Probably in all_mechanisms order, our order of
* preference. Of course when the server is us,
* it lists things in that order anyhow.
*/
if (mech != &all_mechanisms[0])
{
_dbus_verbose ("%s: Adding mechanism %s to list we will try\n",
DBUS_AUTH_NAME (auth), mech->mechanism);
if (!_dbus_list_append (& DBUS_AUTH_CLIENT (auth)->mechs_to_try,
(void*) mech))
{
_dbus_string_free (&m);
goto nomem;
}
}
else
{
_dbus_verbose ("%s: Already tried mechanism %s; not adding to list we will try\n",
DBUS_AUTH_NAME (auth), mech->mechanism);
}
}
else
{
_dbus_verbose ("%s: Server offered mechanism \"%s\" that we don't know how to use\n",
DBUS_AUTH_NAME (auth),
_dbus_string_get_const_data (&m));
}
_dbus_string_free (&m);
}
auth->already_got_mechanisms = TRUE;
return TRUE;
nomem:
_dbus_list_clear (& DBUS_AUTH_CLIENT (auth)->mechs_to_try);
return FALSE;
}
static dbus_bool_t
process_rejected (DBusAuth *auth, const DBusString *args)
{
const DBusAuthMechanismHandler *mech;
DBusAuthClient *client;
client = DBUS_AUTH_CLIENT (auth);
if (!auth->already_got_mechanisms)
{
if (!record_mechanisms (auth, args))
return FALSE;
}
if (DBUS_AUTH_CLIENT (auth)->mechs_to_try != NULL)
{
mech = client->mechs_to_try->data;
if (!send_auth (auth, mech))
return FALSE;
_dbus_list_pop_first (&client->mechs_to_try);
_dbus_verbose ("%s: Trying mechanism %s\n",
DBUS_AUTH_NAME (auth),
mech->mechanism);
}
else
{
/* Give up */
_dbus_verbose ("%s: Disconnecting because we are out of mechanisms to try using\n",
DBUS_AUTH_NAME (auth));
goto_state (auth, &common_state_need_disconnect);
}
return TRUE;
}
static dbus_bool_t
handle_client_state_waiting_for_data (DBusAuth *auth,
DBusAuthCommand command,
const DBusString *args)
{
_dbus_assert (auth->mech != NULL);
switch (command)
{
case DBUS_AUTH_COMMAND_DATA:
return process_data (auth, args, auth->mech->client_data_func);
case DBUS_AUTH_COMMAND_REJECTED:
return process_rejected (auth, args);
case DBUS_AUTH_COMMAND_OK:
return process_ok(auth, args);
case DBUS_AUTH_COMMAND_ERROR:
return send_cancel (auth);
case DBUS_AUTH_COMMAND_AUTH:
case DBUS_AUTH_COMMAND_CANCEL:
case DBUS_AUTH_COMMAND_BEGIN:
case DBUS_AUTH_COMMAND_UNKNOWN:
case DBUS_AUTH_COMMAND_NEGOTIATE_UNIX_FD:
case DBUS_AUTH_COMMAND_AGREE_UNIX_FD:
default:
return send_error (auth, "Unknown command");
}
}
static dbus_bool_t
handle_client_state_waiting_for_ok (DBusAuth *auth,
DBusAuthCommand command,
const DBusString *args)
{
switch (command)
{
case DBUS_AUTH_COMMAND_REJECTED:
return process_rejected (auth, args);
case DBUS_AUTH_COMMAND_OK:
return process_ok(auth, args);
case DBUS_AUTH_COMMAND_DATA:
case DBUS_AUTH_COMMAND_ERROR:
return send_cancel (auth);
case DBUS_AUTH_COMMAND_AUTH:
case DBUS_AUTH_COMMAND_CANCEL:
case DBUS_AUTH_COMMAND_BEGIN:
case DBUS_AUTH_COMMAND_UNKNOWN:
case DBUS_AUTH_COMMAND_NEGOTIATE_UNIX_FD:
case DBUS_AUTH_COMMAND_AGREE_UNIX_FD:
default:
return send_error (auth, "Unknown command");
}
}
static dbus_bool_t
handle_client_state_waiting_for_reject (DBusAuth *auth,
DBusAuthCommand command,
const DBusString *args)
{
switch (command)
{
case DBUS_AUTH_COMMAND_REJECTED:
return process_rejected (auth, args);
case DBUS_AUTH_COMMAND_AUTH:
case DBUS_AUTH_COMMAND_CANCEL:
case DBUS_AUTH_COMMAND_DATA:
case DBUS_AUTH_COMMAND_BEGIN:
case DBUS_AUTH_COMMAND_OK:
case DBUS_AUTH_COMMAND_ERROR:
case DBUS_AUTH_COMMAND_UNKNOWN:
case DBUS_AUTH_COMMAND_NEGOTIATE_UNIX_FD:
case DBUS_AUTH_COMMAND_AGREE_UNIX_FD:
default:
goto_state (auth, &common_state_need_disconnect);
return TRUE;
}
}
static dbus_bool_t
handle_client_state_waiting_for_agree_unix_fd(DBusAuth *auth,
DBusAuthCommand command,
const DBusString *args)
{
switch (command)
{
case DBUS_AUTH_COMMAND_AGREE_UNIX_FD:
_dbus_assert(auth->unix_fd_possible);
auth->unix_fd_negotiated = TRUE;
_dbus_verbose("Successfully negotiated UNIX FD passing\n");
return send_begin (auth);
case DBUS_AUTH_COMMAND_ERROR:
_dbus_assert(auth->unix_fd_possible);
auth->unix_fd_negotiated = FALSE;
_dbus_verbose("Failed to negotiate UNIX FD passing\n");
return send_begin (auth);
case DBUS_AUTH_COMMAND_OK:
case DBUS_AUTH_COMMAND_DATA:
case DBUS_AUTH_COMMAND_REJECTED:
case DBUS_AUTH_COMMAND_AUTH:
case DBUS_AUTH_COMMAND_CANCEL:
case DBUS_AUTH_COMMAND_BEGIN:
case DBUS_AUTH_COMMAND_UNKNOWN:
case DBUS_AUTH_COMMAND_NEGOTIATE_UNIX_FD:
default:
return send_error (auth, "Unknown command");
}
}
/**
* Mapping from command name to enum
*/
typedef struct {
const char *name; /**< Name of the command */
DBusAuthCommand command; /**< Corresponding enum */
} DBusAuthCommandName;
static const DBusAuthCommandName auth_command_names[] = {
{ "AUTH", DBUS_AUTH_COMMAND_AUTH },
{ "CANCEL", DBUS_AUTH_COMMAND_CANCEL },
{ "DATA", DBUS_AUTH_COMMAND_DATA },
{ "BEGIN", DBUS_AUTH_COMMAND_BEGIN },
{ "REJECTED", DBUS_AUTH_COMMAND_REJECTED },
{ "OK", DBUS_AUTH_COMMAND_OK },
{ "ERROR", DBUS_AUTH_COMMAND_ERROR },
{ "NEGOTIATE_UNIX_FD", DBUS_AUTH_COMMAND_NEGOTIATE_UNIX_FD },
{ "AGREE_UNIX_FD", DBUS_AUTH_COMMAND_AGREE_UNIX_FD }
};
static DBusAuthCommand
lookup_command_from_name (DBusString *command)
{
int i;
for (i = 0; i < _DBUS_N_ELEMENTS (auth_command_names); i++)
{
if (_dbus_string_equal_c_str (command,
auth_command_names[i].name))
return auth_command_names[i].command;
}
return DBUS_AUTH_COMMAND_UNKNOWN;
}
static void
goto_state (DBusAuth *auth,
const DBusAuthStateData *state)
{
_dbus_verbose ("%s: going from state %s to state %s\n",
DBUS_AUTH_NAME (auth),
auth->state->name,
state->name);
auth->state = state;
}
/* returns whether to call it again right away */
static dbus_bool_t
process_command (DBusAuth *auth)
{
DBusAuthCommand command;
DBusString line;
DBusString args;
int eol;
int i, j;
dbus_bool_t retval;
/* _dbus_verbose ("%s: trying process_command()\n"); */
retval = FALSE;
eol = 0;
if (!_dbus_string_find (&auth->incoming, 0, "\r\n", &eol))
return FALSE;
if (!_dbus_string_init (&line))
{
auth->needed_memory = TRUE;
return FALSE;
}
if (!_dbus_string_init (&args))
{
_dbus_string_free (&line);
auth->needed_memory = TRUE;
return FALSE;
}
if (!_dbus_string_copy_len (&auth->incoming, 0, eol, &line, 0))
goto out;
if (!_dbus_string_validate_ascii (&line, 0,
_dbus_string_get_length (&line)))
{
_dbus_verbose ("%s: Command contained non-ASCII chars or embedded nul\n",
DBUS_AUTH_NAME (auth));
if (!send_error (auth, "Command contained non-ASCII"))
goto out;
else
goto next_command;
}
_dbus_verbose ("%s: got command \"%s\"\n",
DBUS_AUTH_NAME (auth),
_dbus_string_get_const_data (&line));
_dbus_string_find_blank (&line, 0, &i);
_dbus_string_skip_blank (&line, i, &j);
if (j > i)
_dbus_string_delete (&line, i, j - i);
if (!_dbus_string_move (&line, i, &args, 0))
goto out;
/* FIXME 1.0 we should probably validate that only the allowed
* chars are in the command name
*/
command = lookup_command_from_name (&line);
if (!(* auth->state->handler) (auth, command, &args))
goto out;
next_command:
/* We've succeeded in processing the whole command so drop it out
* of the incoming buffer and return TRUE to try another command.
*/
_dbus_string_delete (&auth->incoming, 0, eol);
/* kill the \r\n */
_dbus_string_delete (&auth->incoming, 0, 2);
retval = TRUE;
out:
_dbus_string_free (&args);
_dbus_string_free (&line);
if (!retval)
auth->needed_memory = TRUE;
else
auth->needed_memory = FALSE;
return retval;
}
/** @} */
/**
* @addtogroup DBusAuth
* @{
*/
/**
* Creates a new auth conversation object for the server side.
* See http://dbus.freedesktop.org/doc/dbus-specification.html#auth-protocol
* for full details on what this object does.
*
* @returns the new object or #NULL if no memory
*/
DBusAuth*
_dbus_auth_server_new (const DBusString *guid)
{
DBusAuth *auth;
DBusAuthServer *server_auth;
DBusString guid_copy;
if (!_dbus_string_init (&guid_copy))
return NULL;
if (!_dbus_string_copy (guid, 0, &guid_copy, 0))
{
_dbus_string_free (&guid_copy);
return NULL;
}
auth = _dbus_auth_new (sizeof (DBusAuthServer));
if (auth == NULL)
{
_dbus_string_free (&guid_copy);
return NULL;
}
auth->side = auth_side_server;
auth->state = &server_state_waiting_for_auth;
server_auth = DBUS_AUTH_SERVER (auth);
server_auth->guid = guid_copy;
/* perhaps this should be per-mechanism with a lower
* max
*/
server_auth->failures = 0;
server_auth->max_failures = 6;
return auth;
}
/**
* Creates a new auth conversation object for the client side.
* See http://dbus.freedesktop.org/doc/dbus-specification.html#auth-protocol
* for full details on what this object does.
*
* @returns the new object or #NULL if no memory
*/
DBusAuth*
_dbus_auth_client_new (void)
{
DBusAuth *auth;
DBusString guid_str;
if (!_dbus_string_init (&guid_str))
return NULL;
auth = _dbus_auth_new (sizeof (DBusAuthClient));
if (auth == NULL)
{
_dbus_string_free (&guid_str);
return NULL;
}
DBUS_AUTH_CLIENT (auth)->guid_from_server = guid_str;
auth->side = auth_side_client;
auth->state = &client_state_need_send_auth;
/* Start the auth conversation by sending AUTH for our default
* mechanism */
if (!send_auth (auth, &all_mechanisms[0]))
{
_dbus_auth_unref (auth);
return NULL;
}
return auth;
}
/**
* Increments the refcount of an auth object.
*
* @param auth the auth conversation
* @returns the auth conversation
*/
DBusAuth *
_dbus_auth_ref (DBusAuth *auth)
{
_dbus_assert (auth != NULL);
auth->refcount += 1;
return auth;
}
/**
* Decrements the refcount of an auth object.
*
* @param auth the auth conversation
*/
void
_dbus_auth_unref (DBusAuth *auth)
{
_dbus_assert (auth != NULL);
_dbus_assert (auth->refcount > 0);
auth->refcount -= 1;
if (auth->refcount == 0)
{
shutdown_mech (auth);
if (DBUS_AUTH_IS_CLIENT (auth))
{
_dbus_string_free (& DBUS_AUTH_CLIENT (auth)->guid_from_server);
_dbus_list_clear (& DBUS_AUTH_CLIENT (auth)->mechs_to_try);
}
else
{
_dbus_assert (DBUS_AUTH_IS_SERVER (auth));
_dbus_string_free (& DBUS_AUTH_SERVER (auth)->guid);
}
if (auth->keyring)
_dbus_keyring_unref (auth->keyring);
_dbus_string_free (&auth->context);
_dbus_string_free (&auth->challenge);
_dbus_string_free (&auth->identity);
_dbus_string_free (&auth->incoming);
_dbus_string_free (&auth->outgoing);
dbus_free_string_array (auth->allowed_mechs);
_dbus_credentials_unref (auth->credentials);
_dbus_credentials_unref (auth->authorized_identity);
_dbus_credentials_unref (auth->desired_identity);
dbus_free (auth);
}
}
/**
* Sets an array of authentication mechanism names
* that we are willing to use.
*
* @param auth the auth conversation
* @param mechanisms #NULL-terminated array of mechanism names
* @returns #FALSE if no memory
*/
dbus_bool_t
_dbus_auth_set_mechanisms (DBusAuth *auth,
const char **mechanisms)
{
char **copy;
if (mechanisms != NULL)
{
copy = _dbus_dup_string_array (mechanisms);
if (copy == NULL)
return FALSE;
}
else
copy = NULL;
dbus_free_string_array (auth->allowed_mechs);
auth->allowed_mechs = copy;
return TRUE;
}
/**
* @param auth the auth conversation object
* @returns #TRUE if we're in a final state
*/
#define DBUS_AUTH_IN_END_STATE(auth) ((auth)->state->handler == NULL)
/**
* Analyzes buffered input and moves the auth conversation forward,
* returning the new state of the auth conversation.
*
* @param auth the auth conversation
* @returns the new state
*/
DBusAuthState
_dbus_auth_do_work (DBusAuth *auth)
{
auth->needed_memory = FALSE;
/* Max amount we'll buffer up before deciding someone's on crack */
#define MAX_BUFFER (16 * _DBUS_ONE_KILOBYTE)
do
{
if (DBUS_AUTH_IN_END_STATE (auth))
break;
if (_dbus_string_get_length (&auth->incoming) > MAX_BUFFER ||
_dbus_string_get_length (&auth->outgoing) > MAX_BUFFER)
{
goto_state (auth, &common_state_need_disconnect);
_dbus_verbose ("%s: Disconnecting due to excessive data buffered in auth phase\n",
DBUS_AUTH_NAME (auth));
break;
}
}
while (process_command (auth));
if (auth->needed_memory)
return DBUS_AUTH_STATE_WAITING_FOR_MEMORY;
else if (_dbus_string_get_length (&auth->outgoing) > 0)
return DBUS_AUTH_STATE_HAVE_BYTES_TO_SEND;
else if (auth->state == &common_state_need_disconnect)
return DBUS_AUTH_STATE_NEED_DISCONNECT;
else if (auth->state == &common_state_authenticated)
return DBUS_AUTH_STATE_AUTHENTICATED;
else return DBUS_AUTH_STATE_WAITING_FOR_INPUT;
}
/**
* Gets bytes that need to be sent to the peer we're conversing with.
* After writing some bytes, _dbus_auth_bytes_sent() must be called
* to notify the auth object that they were written.
*
* @param auth the auth conversation
* @param str return location for a ref to the buffer to send
* @returns #FALSE if nothing to send
*/
dbus_bool_t
_dbus_auth_get_bytes_to_send (DBusAuth *auth,
const DBusString **str)
{
_dbus_assert (auth != NULL);
_dbus_assert (str != NULL);
*str = NULL;
if (_dbus_string_get_length (&auth->outgoing) == 0)
return FALSE;
*str = &auth->outgoing;
return TRUE;
}
/**
* Notifies the auth conversation object that
* the given number of bytes of the outgoing buffer
* have been written out.
*
* @param auth the auth conversation
* @param bytes_sent number of bytes written out
*/
void
_dbus_auth_bytes_sent (DBusAuth *auth,
int bytes_sent)
{
_dbus_verbose ("%s: Sent %d bytes of: %s\n",
DBUS_AUTH_NAME (auth),
bytes_sent,
_dbus_string_get_const_data (&auth->outgoing));
_dbus_string_delete (&auth->outgoing,
0, bytes_sent);
}
/**
* Get a buffer to be used for reading bytes from the peer we're conversing
* with. Bytes should be appended to this buffer.
*
* @param auth the auth conversation
* @param buffer return location for buffer to append bytes to
*/
void
_dbus_auth_get_buffer (DBusAuth *auth,
DBusString **buffer)
{
_dbus_assert (auth != NULL);
_dbus_assert (!auth->buffer_outstanding);
*buffer = &auth->incoming;
auth->buffer_outstanding = TRUE;
}
/**
* Returns a buffer with new data read into it.
*
* @param auth the auth conversation
* @param buffer the buffer being returned
*/
void
_dbus_auth_return_buffer (DBusAuth *auth,
DBusString *buffer)
{
_dbus_assert (buffer == &auth->incoming);
_dbus_assert (auth->buffer_outstanding);
auth->buffer_outstanding = FALSE;
}
/**
* Returns leftover bytes that were not used as part of the auth
* conversation. These bytes will be part of the message stream
* instead. This function may not be called until authentication has
* succeeded.
*
* @param auth the auth conversation
* @param str return location for pointer to string of unused bytes
*/
void
_dbus_auth_get_unused_bytes (DBusAuth *auth,
const DBusString **str)
{
if (!DBUS_AUTH_IN_END_STATE (auth))
return;
*str = &auth->incoming;
}
/**
* Gets rid of unused bytes returned by _dbus_auth_get_unused_bytes()
* after we've gotten them and successfully moved them elsewhere.
*
* @param auth the auth conversation
*/
void
_dbus_auth_delete_unused_bytes (DBusAuth *auth)
{
if (!DBUS_AUTH_IN_END_STATE (auth))
return;
_dbus_string_set_length (&auth->incoming, 0);
}
/**
* Called post-authentication, indicates whether we need to encode
* the message stream with _dbus_auth_encode_data() prior to
* sending it to the peer.
*
* @param auth the auth conversation
* @returns #TRUE if we need to encode the stream
*/
dbus_bool_t
_dbus_auth_needs_encoding (DBusAuth *auth)
{
if (auth->state != &common_state_authenticated)
return FALSE;
if (auth->mech != NULL)
{
if (DBUS_AUTH_IS_CLIENT (auth))
return auth->mech->client_encode_func != NULL;
else
return auth->mech->server_encode_func != NULL;
}
else
return FALSE;
}
/**
* Called post-authentication, encodes a block of bytes for sending to
* the peer. If no encoding was negotiated, just copies the bytes
* (you can avoid this by checking _dbus_auth_needs_encoding()).
*
* @param auth the auth conversation
* @param plaintext the plain text data
* @param encoded initialized string to where encoded data is appended
* @returns #TRUE if we had enough memory and successfully encoded
*/
dbus_bool_t
_dbus_auth_encode_data (DBusAuth *auth,
const DBusString *plaintext,
DBusString *encoded)
{
_dbus_assert (plaintext != encoded);
if (auth->state != &common_state_authenticated)
return FALSE;
if (_dbus_auth_needs_encoding (auth))
{
if (DBUS_AUTH_IS_CLIENT (auth))
return (* auth->mech->client_encode_func) (auth, plaintext, encoded);
else
return (* auth->mech->server_encode_func) (auth, plaintext, encoded);
}
else
{
return _dbus_string_copy (plaintext, 0, encoded,
_dbus_string_get_length (encoded));
}
}
/**
* Called post-authentication, indicates whether we need to decode
* the message stream with _dbus_auth_decode_data() after
* receiving it from the peer.
*
* @param auth the auth conversation
* @returns #TRUE if we need to encode the stream
*/
dbus_bool_t
_dbus_auth_needs_decoding (DBusAuth *auth)
{
if (auth->state != &common_state_authenticated)
return FALSE;
if (auth->mech != NULL)
{
if (DBUS_AUTH_IS_CLIENT (auth))
return auth->mech->client_decode_func != NULL;
else
return auth->mech->server_decode_func != NULL;
}
else
return FALSE;
}
/**
* Called post-authentication, decodes a block of bytes received from
* the peer. If no encoding was negotiated, just copies the bytes (you
* can avoid this by checking _dbus_auth_needs_decoding()).
*
* @todo 1.0? We need to be able to distinguish "out of memory" error
* from "the data is hosed" error.
*
* @param auth the auth conversation
* @param encoded the encoded data
* @param plaintext initialized string where decoded data is appended
* @returns #TRUE if we had enough memory and successfully decoded
*/
dbus_bool_t
_dbus_auth_decode_data (DBusAuth *auth,
const DBusString *encoded,
DBusString *plaintext)
{
_dbus_assert (plaintext != encoded);
if (auth->state != &common_state_authenticated)
return FALSE;
if (_dbus_auth_needs_decoding (auth))
{
if (DBUS_AUTH_IS_CLIENT (auth))
return (* auth->mech->client_decode_func) (auth, encoded, plaintext);
else
return (* auth->mech->server_decode_func) (auth, encoded, plaintext);
}
else
{
return _dbus_string_copy (encoded, 0, plaintext,
_dbus_string_get_length (plaintext));
}
}
/**
* Sets credentials received via reliable means from the operating
* system.
*
* @param auth the auth conversation
* @param credentials the credentials received
* @returns #FALSE on OOM
*/
dbus_bool_t
_dbus_auth_set_credentials (DBusAuth *auth,
DBusCredentials *credentials)
{
_dbus_credentials_clear (auth->credentials);
return _dbus_credentials_add_credentials (auth->credentials,
credentials);
}
/**
* Gets the identity we authorized the client as. Apps may have
* different policies as to what identities they allow.
*
* Returned credentials are not a copy and should not be modified
*
* @param auth the auth conversation
* @returns the credentials we've authorized BY REFERENCE do not modify
*/
DBusCredentials*
_dbus_auth_get_identity (DBusAuth *auth)
{
if (auth->state == &common_state_authenticated)
{
return auth->authorized_identity;
}
else
{
/* FIXME instead of this, keep an empty credential around that
* doesn't require allocation or something
*/
/* return empty credentials */
_dbus_assert (_dbus_credentials_are_empty (auth->authorized_identity));
return auth->authorized_identity;
}
}
/**
* Gets the GUID from the server if we've authenticated; gets
* #NULL otherwise.
* @param auth the auth object
* @returns the GUID in ASCII hex format
*/
const char*
_dbus_auth_get_guid_from_server (DBusAuth *auth)
{
_dbus_assert (DBUS_AUTH_IS_CLIENT (auth));
if (auth->state == &common_state_authenticated)
return _dbus_string_get_const_data (& DBUS_AUTH_CLIENT (auth)->guid_from_server);
else
return NULL;
}
/**
* Sets the "authentication context" which scopes cookies
* with the DBUS_COOKIE_SHA1 auth mechanism for example.
*
* @param auth the auth conversation
* @param context the context
* @returns #FALSE if no memory
*/
dbus_bool_t
_dbus_auth_set_context (DBusAuth *auth,
const DBusString *context)
{
return _dbus_string_replace_len (context, 0, _dbus_string_get_length (context),
&auth->context, 0, _dbus_string_get_length (context));
}
/**
* Sets whether unix fd passing is potentially on the transport and
* hence shall be negotiated.
*
* @param auth the auth conversation
* @param b TRUE when unix fd passing shall be negotiated, otherwise FALSE
*/
void
_dbus_auth_set_unix_fd_possible(DBusAuth *auth, dbus_bool_t b)
{
auth->unix_fd_possible = b;
}
/**
* Queries whether unix fd passing was successfully negotiated.
*
* @param auth the auth conversion
* @returns #TRUE when unix fd passing was negotiated.
*/
dbus_bool_t
_dbus_auth_get_unix_fd_negotiated(DBusAuth *auth)
{
return auth->unix_fd_negotiated;
}
/**
* Queries whether the given auth mechanism is supported.
*
* @param auth the auth mechanism to query for
* @returns #TRUE when auth mechanism is supported
*/
dbus_bool_t
_dbus_auth_is_supported_mechanism (DBusString *name)
{
_dbus_assert (name != NULL);
return find_mech (name, NULL) != NULL;
}
/**
* Return a human-readable string containing all supported auth mechanisms.
*
* @param string to hold the supported auth mechanisms
* @returns #FALSE on oom
*/
dbus_bool_t
_dbus_auth_dump_supported_mechanisms (DBusString *buffer)
{
unsigned int i;
_dbus_assert (buffer != NULL);
for (i = 0; all_mechanisms[i].mechanism != NULL; i++)
{
if (i > 0)
{
if (!_dbus_string_append (buffer, ", "))
return FALSE;
}
if (!_dbus_string_append (buffer, all_mechanisms[i].mechanism))
return FALSE;
}
return TRUE;
}
/** @} */
/* tests in dbus-auth-util.c */
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