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xmpp.chapril.org-ejabberd/src/ejabberd_auth_ldap.erl
Mickaël Rémond 90488e5f37 * src/ejabberd_auth_ldap.erl: prevent anonymous bind on LDAP servers
as ejabberd is providing other anonymous authentication mechanism
(EJAB-190).

SVN Revision: 731
2007-02-19 13:27:18 +00:00

378 lines
11 KiB
Erlang

%%%----------------------------------------------------------------------
%%% File : ejabberd_auth_ldap.erl
%%% Author : Alexey Shchepin <alexey@sevcom.net>
%%% Purpose : Authentification via LDAP
%%% Created : 12 Dec 2004 by Alexey Shchepin <alexey@sevcom.net>
%%% Id : $Id$
%%%----------------------------------------------------------------------
-module(ejabberd_auth_ldap).
-author('alexey@sevcom.net').
-vsn('$Revision$ ').
-behaviour(gen_server).
%% gen_server callbacks
-export([init/1,
handle_info/2,
handle_call/3,
handle_cast/2,
terminate/2,
code_change/3
]).
%% External exports
-export([start/1,
stop/1,
start_link/1,
set_password/3,
check_password/3,
check_password/5,
try_register/3,
dirty_get_registered_users/0,
get_vh_registered_users/1,
get_password/2,
get_password_s/2,
is_user_exists/2,
remove_user/2,
remove_user/3,
plain_password_required/0
]).
-include("ejabberd.hrl").
-include("eldap/eldap.hrl").
-record(state, {host,
eldap_id,
bind_eldap_id,
servers,
backups,
port,
dn,
password,
base,
uids,
ufilter,
sfilter,
lfilter, %% Local filter (performed by ejabberd, not LDAP)
dn_filter,
dn_filter_attrs
}).
%% Unused callbacks.
handle_cast(_Request, State) ->
{noreply, State}.
code_change(_OldVsn, State, _Extra) ->
{ok, State}.
handle_info(_Info, State) ->
{noreply, State}.
%% -----
%%%----------------------------------------------------------------------
%%% API
%%%----------------------------------------------------------------------
start(Host) ->
Proc = gen_mod:get_module_proc(Host, ?MODULE),
ChildSpec = {
Proc, {?MODULE, start_link, [Host]},
transient, 1000, worker, [?MODULE]
},
supervisor:start_child(ejabberd_sup, ChildSpec).
stop(Host) ->
Proc = gen_mod:get_module_proc(Host, ?MODULE),
gen_server:call(Proc, stop),
supervisor:terminate_child(ejabberd_sup, Proc),
supervisor:delete_child(ejabberd_sup, Proc).
start_link(Host) ->
Proc = gen_mod:get_module_proc(Host, ?MODULE),
gen_server:start_link({local, Proc}, ?MODULE, Host, []).
terminate(_Reason, State) ->
ejabberd_ctl:unregister_commands(
State#state.host,
[{"registered-users", "list all registered users"}],
ejabberd_auth, ctl_process_get_registered).
init(Host) ->
State = parse_options(Host),
eldap_pool:start_link(State#state.eldap_id,
State#state.servers,
State#state.backups,
State#state.port,
State#state.dn,
State#state.password),
eldap_pool:start_link(State#state.bind_eldap_id,
State#state.servers,
State#state.backups,
State#state.port,
State#state.dn,
State#state.password),
ejabberd_ctl:register_commands(
Host,
[{"registered-users", "list all registered users"}],
ejabberd_auth, ctl_process_get_registered),
{ok, State}.
plain_password_required() ->
true.
check_password(User, Server, Password) ->
%% In LDAP spec: empty password means anonymous authentication.
%% As ejabberd is providing other anonymous authentication mechanisms
%% we simply prevent the use of LDAP anonymous authentication.
if Password == "" ->
false;
true ->
case catch check_password_ldap(User, Server, Password) of
{'EXIT', _} -> false;
Result -> Result
end
end.
check_password(User, Server, Password, _StreamID, _Digest) ->
check_password(User, Server, Password).
set_password(_User, _Server, _Password) ->
{error, not_allowed}.
try_register(_User, _Server, _Password) ->
{error, not_allowed}.
dirty_get_registered_users() ->
get_vh_registered_users(?MYNAME).
get_vh_registered_users(Server) ->
case catch get_vh_registered_users_ldap(Server) of
{'EXIT', _} -> [];
Result -> Result
end.
get_password(_User, _Server) ->
false.
get_password_s(_User, _Server) ->
"".
is_user_exists(User, Server) ->
case catch is_user_exists_ldap(User, Server) of
{'EXIT', _} ->
false;
Result ->
Result
end.
remove_user(_User, _Server) ->
{error, not_allowed}.
remove_user(_User, _Server, _Password) ->
not_allowed.
%%%----------------------------------------------------------------------
%%% Internal functions
%%%----------------------------------------------------------------------
check_password_ldap(User, Server, Password) ->
{ok, State} = eldap_utils:get_state(Server, ?MODULE),
case find_user_dn(User, State) of
false ->
false;
DN ->
case eldap_pool:bind(State#state.bind_eldap_id, DN, Password) of
ok -> true;
_ -> false
end
end.
get_vh_registered_users_ldap(Server) ->
{ok, State} = eldap_utils:get_state(Server, ?MODULE),
UIDs = State#state.uids,
Eldap_ID = State#state.eldap_id,
Server = State#state.host,
SortedDNAttrs = eldap_utils:usort_attrs(State#state.dn_filter_attrs),
case eldap_filter:parse(State#state.sfilter) of
{ok, EldapFilter} ->
case eldap_pool:search(Eldap_ID, [{base, State#state.base},
{filter, EldapFilter},
{attributes, SortedDNAttrs}]) of
#eldap_search_result{entries = Entries} ->
lists:flatmap(
fun(#eldap_entry{attributes = Attrs,
object_name = DN}) ->
case is_valid_dn(DN, Attrs, State) of
false -> [];
_ ->
case eldap_utils:find_ldap_attrs(UIDs, Attrs) of
"" -> [];
{User, UIDFormat} ->
case eldap_utils:get_user_part(User, UIDFormat) of
{ok, U} ->
case jlib:nodeprep(U) of
error -> [];
LU -> [{LU, jlib:nameprep(Server)}]
end;
_ -> []
end
end
end
end, Entries);
_ ->
[]
end;
_ ->
[]
end.
is_user_exists_ldap(User, Server) ->
{ok, State} = eldap_utils:get_state(Server, ?MODULE),
case find_user_dn(User, State) of
false -> false;
_DN -> true
end.
handle_call(get_state, _From, State) ->
{reply, {ok, State}, State};
handle_call(stop, _From, State) ->
{stop, normal, ok, State};
handle_call(_Request, _From, State) ->
{reply, bad_request, State}.
find_user_dn(User, State) ->
DNAttrs = eldap_utils:usort_attrs(State#state.dn_filter_attrs),
case eldap_filter:parse(State#state.ufilter, [{"%u", User}]) of
{ok, Filter} ->
case eldap_pool:search(State#state.eldap_id, [{base, State#state.base},
{filter, Filter},
{attributes, DNAttrs}]) of
#eldap_search_result{entries = [#eldap_entry{attributes = Attrs,
object_name = DN} | _]} ->
dn_filter(DN, Attrs, State);
_ ->
false
end;
_ ->
false
end.
%% apply the dn filter and the local filter:
dn_filter(DN, Attrs, State) ->
%% Check if user is denied access by attribute value (local check)
case check_local_filter(Attrs, State) of
false -> false;
true -> is_valid_dn(DN, Attrs, State)
end.
%% Check that the DN is valid, based on the dn filter
is_valid_dn(DN, _, #state{dn_filter = undefined}) ->
DN;
is_valid_dn(DN, Attrs, State) ->
DNAttrs = State#state.dn_filter_attrs,
UIDs = State#state.uids,
Values = [{"%s", eldap_utils:get_ldap_attr(Attr, Attrs), 1} || Attr <- DNAttrs],
SubstValues = case eldap_utils:find_ldap_attrs(UIDs, Attrs) of
"" -> Values;
{S, UAF} ->
case eldap_utils:get_user_part(S, UAF) of
{ok, U} -> [{"%u", U} | Values];
_ -> Values
end
end ++ [{"%d", State#state.host}, {"%D", DN}],
case eldap_filter:parse(State#state.dn_filter, SubstValues) of
{ok, EldapFilter} ->
case eldap_pool:search(State#state.eldap_id, [
{base, State#state.base},
{filter, EldapFilter},
{attributes, ["dn"]}]) of
#eldap_search_result{entries = [_|_]} ->
DN;
_ ->
false
end;
_ ->
false
end.
%% The local filter is used to check an attribute in ejabberd
%% and not in LDAP to limit the load on the LDAP directory.
%% A local rule can be either:
%% {equal, {"accountStatus",["active"]}}
%% {notequal, {"accountStatus",["disabled"]}}
%% {ldap_local_filter, {notequal, {"accountStatus",["disabled"]}}}
check_local_filter(_Attrs, #state{lfilter = undefined}) ->
true;
check_local_filter(Attrs, #state{lfilter = LocalFilter}) ->
{Operation, FilterMatch} = LocalFilter,
local_filter(Operation, Attrs, FilterMatch).
local_filter(equal, Attrs, FilterMatch) ->
{Attr, Value} = FilterMatch,
case lists:keysearch(Attr, 1, Attrs) of
false -> false;
{value,{Attr,Value}} -> true;
_ -> false
end;
local_filter(notequal, Attrs, FilterMatch) ->
not local_filter(equal, Attrs, FilterMatch).
%%%----------------------------------------------------------------------
%%% Auxiliary functions
%%%----------------------------------------------------------------------
parse_options(Host) ->
Eldap_ID = atom_to_list(gen_mod:get_module_proc(Host, ?MODULE)),
Bind_Eldap_ID = atom_to_list(gen_mod:get_module_proc(Host, bind_ejabberd_auth_ldap)),
LDAPServers = ejabberd_config:get_local_option({ldap_servers, Host}),
LDAPBackups = case ejabberd_config:get_local_option({ldap_backups, Host}) of
undefined -> [];
Backups -> Backups
end,
LDAPPort = case ejabberd_config:get_local_option({ldap_port, Host}) of
undefined -> 389;
P -> P
end,
RootDN = case ejabberd_config:get_local_option({ldap_rootdn, Host}) of
undefined -> "";
RDN -> RDN
end,
Password = case ejabberd_config:get_local_option({ldap_password, Host}) of
undefined -> "";
Pass -> Pass
end,
UIDs = case ejabberd_config:get_local_option({ldap_uids, Host}) of
undefined -> [{"uid", "%u"}];
UI -> eldap_utils:uids_domain_subst(Host, UI)
end,
SubFilter = lists:flatten(eldap_utils:generate_subfilter(UIDs)),
UserFilter = case ejabberd_config:get_local_option({ldap_filter, Host}) of
undefined -> SubFilter;
"" -> SubFilter;
F -> "(&" ++ SubFilter ++ F ++ ")"
end,
SearchFilter = eldap_filter:do_sub(UserFilter, [{"%u", "*"}]),
LDAPBase = ejabberd_config:get_local_option({ldap_base, Host}),
{DNFilter, DNFilterAttrs} =
case ejabberd_config:get_local_option({ldap_dn_filter, Host}) of
undefined -> {undefined, undefined};
{DNF, DNFA} -> {DNF, DNFA}
end,
LocalFilter = ejabberd_config:get_local_option({ldap_local_filter, Host}),
#state{host = Host,
eldap_id = Eldap_ID,
bind_eldap_id = Bind_Eldap_ID,
servers = LDAPServers,
backups = LDAPBackups,
port = LDAPPort,
dn = RootDN,
password = Password,
base = LDAPBase,
uids = UIDs,
ufilter = UserFilter,
sfilter = SearchFilter,
lfilter = LocalFilter,
dn_filter = DNFilter,
dn_filter_attrs = DNFilterAttrs
}.