%%%----------------------------------------------------------------------
%%% File : mod_register.erl
%%% Author : Alexey Shchepin <alexey@process-one.net>
%%% Purpose : Inband registration support
%%% Created : 8 Dec 2002 by Alexey Shchepin <alexey@process-one.net>
%%%
%%%
%%% ejabberd, Copyright (C) 2002-2020 ProcessOne
%%%
%%% 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.
%%%
%%%----------------------------------------------------------------------
-module(mod_register).
-author('alexey@process-one.net').
-protocol({xep, 77, '2.4'}).
-behaviour(gen_mod).
-export([start/2, stop/1, reload/3, stream_feature_register/2,
c2s_unauthenticated_packet/2, try_register/4,
process_iq/1, send_registration_notifications/3,
mod_opt_type/1, mod_options/1, depends/2,
format_error/1, mod_doc/0]).
-include("logger.hrl").
-include_lib("xmpp/include/xmpp.hrl").
-include("translate.hrl").
start(Host, _Opts) ->
gen_iq_handler:add_iq_handler(ejabberd_local, Host,
?NS_REGISTER, ?MODULE, process_iq),
gen_iq_handler:add_iq_handler(ejabberd_sm, Host,
?NS_REGISTER, ?MODULE, process_iq),
ejabberd_hooks:add(c2s_pre_auth_features, Host, ?MODULE,
stream_feature_register, 50),
ejabberd_hooks:add(c2s_unauthenticated_packet, Host,
?MODULE, c2s_unauthenticated_packet, 50),
ejabberd_mnesia:create(?MODULE, mod_register_ip,
[{ram_copies, [node()]}, {local_content, true},
{attributes, [key, value]}]),
ok.
stop(Host) ->
ejabberd_hooks:delete(c2s_pre_auth_features, Host,
?MODULE, stream_feature_register, 50),
ejabberd_hooks:delete(c2s_unauthenticated_packet, Host,
?MODULE, c2s_unauthenticated_packet, 50),
gen_iq_handler:remove_iq_handler(ejabberd_local, Host,
?NS_REGISTER),
gen_iq_handler:remove_iq_handler(ejabberd_sm, Host,
?NS_REGISTER).
reload(_Host, _NewOpts, _OldOpts) ->
ok.
depends(_Host, _Opts) ->
[].
-spec stream_feature_register([xmpp_element()], binary()) -> [xmpp_element()].
stream_feature_register(Acc, Host) ->
case {mod_register_opt:access(Host),
mod_register_opt:ip_access(Host),
mod_register_opt:redirect_url(Host)} of
{none, _, undefined} -> Acc;
{_, none, undefined} -> Acc;
{_, _, _} -> [#feature_register{}|Acc]
end.
c2s_unauthenticated_packet(#{ip := IP, server := Server} = State,
#iq{type = T, sub_els = [_]} = IQ)
when T == set; T == get ->
try xmpp:try_subtag(IQ, #register{}) of
#register{} = Register ->
{Address, _} = IP,
IQ1 = xmpp:set_els(IQ, [Register]),
IQ2 = xmpp:set_from_to(IQ1, jid:make(<<>>), jid:make(Server)),
ResIQ = process_iq(IQ2, Address),
ResIQ1 = xmpp:set_from_to(ResIQ, jid:make(Server), undefined),
{stop, ejabberd_c2s:send(State, ResIQ1)};
false ->
State
catch _:{xmpp_codec, Why} ->
Txt = xmpp:io_format_error(Why),
Lang = maps:get(lang, State),
Err = xmpp:make_error(IQ, xmpp:err_bad_request(Txt, Lang)),
{stop, ejabberd_c2s:send(State, Err)}
end;
c2s_unauthenticated_packet(State, _) ->
State.
process_iq(#iq{from = From} = IQ) ->
process_iq(IQ, jid:tolower(From)).
process_iq(#iq{from = From, to = To} = IQ, Source) ->
IsCaptchaEnabled =
case mod_register_opt:captcha_protected(To#jid.lserver) of
true -> true;
false -> false
end,
Server = To#jid.lserver,
Access = mod_register_opt:access_remove(Server),
Remove = case {acl:match_rule(Server, Access, From), From#jid.lserver} of
{allow, Server} ->
allow;
{_, _} ->
deny
end,
process_iq(IQ, Source, IsCaptchaEnabled, Remove == allow).
process_iq(#iq{type = set, lang = Lang,
sub_els = [#register{remove = true}]} = IQ,
_Source, _IsCaptchaEnabled, _AllowRemove = false) ->
Txt = ?T("Access denied by service policy"),
xmpp:make_error(IQ, xmpp:err_forbidden(Txt, Lang));
process_iq(#iq{type = set, lang = Lang, to = To, from = From,
sub_els = [#register{remove = true,
username = User,
password = Password}]} = IQ,
_Source, _IsCaptchaEnabled, _AllowRemove = true) ->
Server = To#jid.lserver,
if is_binary(User) ->
case From of
#jid{user = User, lserver = Server} ->
ResIQ = xmpp:make_iq_result(IQ),
ejabberd_router:route(ResIQ),
ejabberd_auth:remove_user(User, Server),
ignore;
_ ->
if is_binary(Password) ->
case ejabberd_auth:check_password(
User, <<"">>, Server, Password) of
true ->
ResIQ = xmpp:make_iq_result(IQ),
ejabberd_router:route(ResIQ),
ejabberd_auth:remove_user(User, Server),
ignore;
false ->
Txt = ?T("Incorrect password"),
xmpp:make_error(
IQ, xmpp:err_forbidden(Txt, Lang))
end;
true ->
Txt = ?T("No 'password' found in this query"),
xmpp:make_error(IQ, xmpp:err_bad_request(Txt, Lang))
end
end;
true ->
case From of
#jid{luser = LUser, lserver = Server} ->
ResIQ = xmpp:make_iq_result(IQ),
ejabberd_router:route(xmpp:set_from_to(ResIQ, From, From)),
ejabberd_auth:remove_user(LUser, Server),
ignore;
_ ->
Txt = ?T("The query is only allowed from local users"),
xmpp:make_error(IQ, xmpp:err_not_allowed(Txt, Lang))
end
end;
process_iq(#iq{type = set, to = To,
sub_els = [#register{username = User,
password = Password}]} = IQ,
Source, IsCaptchaEnabled, _AllowRemove) when is_binary(User),
is_binary(Password) ->
Server = To#jid.lserver,
try_register_or_set_password(
User, Server, Password, IQ, Source, not IsCaptchaEnabled);
process_iq(#iq{type = set, to = To,
lang = Lang, sub_els = [#register{xdata = #xdata{} = X}]} = IQ,
Source, true, _AllowRemove) ->
Server = To#jid.lserver,
case ejabberd_captcha:process_reply(X) of
ok ->
case process_xdata_submit(X) of
{ok, User, Password} ->
try_register_or_set_password(
User, Server, Password, IQ, Source, true);
_ ->
Txt = ?T("Incorrect data form"),
xmpp:make_error(IQ, xmpp:err_bad_request(Txt, Lang))
end;
{error, malformed} ->
Txt = ?T("Incorrect CAPTCHA submit"),
xmpp:make_error(IQ, xmpp:err_bad_request(Txt, Lang));
_ ->
ErrText = ?T("The CAPTCHA verification has failed"),
xmpp:make_error(IQ, xmpp:err_not_allowed(ErrText, Lang))
end;
process_iq(#iq{type = set} = IQ, _Source, _IsCaptchaEnabled, _AllowRemove) ->
xmpp:make_error(IQ, xmpp:err_bad_request());
process_iq(#iq{type = get, from = From, to = To, id = ID, lang = Lang} = IQ,
Source, IsCaptchaEnabled, _AllowRemove) ->
Server = To#jid.lserver,
{IsRegistered, Username} =
case From of
#jid{user = User, lserver = Server} ->
case ejabberd_auth:user_exists(User, Server) of
true ->
{true, User};
false ->
{false, User}
end;
_ ->
{false, <<"">>}
end,
Instr = translate:translate(
Lang, ?T("Choose a username and password to register "
"with this server")),
URL = mod_register_opt:redirect_url(Server),
if (URL /= undefined) and not IsRegistered ->
Desc = str:translate_and_format(Lang, ?T("To register, visit ~s"), [URL]),
xmpp:make_iq_result(
IQ, #register{instructions = Desc,
sub_els = [#oob_x{url = URL}]});
IsCaptchaEnabled and not IsRegistered ->
TopInstr = translate:translate(
Lang, ?T("You need a client that supports x:data "
"and CAPTCHA to register")),
UField = #xdata_field{type = 'text-single',
label = translate:translate(Lang, ?T("User")),
var = <<"username">>,
required = true},
PField = #xdata_field{type = 'text-private',
label = translate:translate(Lang, ?T("Password")),
var = <<"password">>,
required = true},
X = #xdata{type = form, instructions = [Instr],
fields = [UField, PField]},
case ejabberd_captcha:create_captcha_x(ID, To, Lang, Source, X) of
{ok, CaptchaEls} ->
xmpp:make_iq_result(
IQ, #register{instructions = TopInstr,
sub_els = CaptchaEls});
{error, limit} ->
ErrText = ?T("Too many CAPTCHA requests"),
xmpp:make_error(
IQ, xmpp:err_resource_constraint(ErrText, Lang));
_Err ->
ErrText = ?T("Unable to generate a CAPTCHA"),
xmpp:make_error(
IQ, xmpp:err_internal_server_error(ErrText, Lang))
end;
true ->
xmpp:make_iq_result(
IQ,
#register{instructions = Instr,
username = Username,
password = <<"">>,
registered = IsRegistered})
end.
try_register_or_set_password(User, Server, Password,
#iq{from = From, lang = Lang} = IQ,
Source, CaptchaSucceed) ->
case From of
#jid{user = User, lserver = Server} ->
try_set_password(User, Server, Password, IQ);
_ when CaptchaSucceed ->
case check_from(From, Server) of
allow ->
case try_register(User, Server, Password, Source, Lang) of
ok ->
xmpp:make_iq_result(IQ);
{error, Error} ->
xmpp:make_error(IQ, Error)
end;
deny ->
Txt = ?T("Access denied by service policy"),
xmpp:make_error(IQ, xmpp:err_forbidden(Txt, Lang))
end;
_ ->
xmpp:make_error(IQ, xmpp:err_not_allowed())
end.
try_set_password(User, Server, Password) ->
case is_strong_password(Server, Password) of
true ->
ejabberd_auth:set_password(User, Server, Password);
error_preparing_password ->
{error, invalid_password};
false ->
{error, weak_password}
end.
try_set_password(User, Server, Password, #iq{lang = Lang, meta = M} = IQ) ->
case try_set_password(User, Server, Password) of
ok ->
?INFO_MSG("~ts has changed password from ~ts",
[jid:encode({User, Server, <<"">>}),
ejabberd_config:may_hide_data(
misc:ip_to_list(maps:get(ip, M, {0,0,0,0})))]),
xmpp:make_iq_result(IQ);
{error, not_allowed} ->
Txt = ?T("Changing password is not allowed"),
xmpp:make_error(IQ, xmpp:err_not_allowed(Txt, Lang));
{error, invalid_jid = Why} ->
xmpp:make_error(IQ, xmpp:err_jid_malformed(format_error(Why), Lang));
{error, invalid_password = Why} ->
xmpp:make_error(IQ, xmpp:err_not_allowed(format_error(Why), Lang));
{error, weak_password = Why} ->
xmpp:make_error(IQ, xmpp:err_not_acceptable(format_error(Why), Lang));
{error, db_failure = Why} ->
xmpp:make_error(IQ, xmpp:err_internal_server_error(format_error(Why), Lang))
end.
try_register(User, Server, Password, SourceRaw) ->
case jid:is_nodename(User) of
false ->
{error, invalid_jid};
true ->
case check_access(User, Server, SourceRaw) of
deny ->
{error, eaccess};
allow ->
Source = may_remove_resource(SourceRaw),
case check_timeout(Source) of
true ->
case is_strong_password(Server, Password) of
true ->
case ejabberd_auth:try_register(
User, Server, Password) of
ok ->
ok;
{error, _} = Err ->
remove_timeout(Source),
Err
end;
false ->
remove_timeout(Source),
{error, weak_password};
error_preparing_password ->
remove_timeout(Source),
{error, invalid_password}
end;
false ->
{error, wait}
end
end
end.
try_register(User, Server, Password, SourceRaw, Lang) ->
case try_register(User, Server, Password, SourceRaw) of
ok ->
JID = jid:make(User, Server),
Source = may_remove_resource(SourceRaw),
?INFO_MSG("The account ~ts was registered from IP address ~ts",
[jid:encode({User, Server, <<"">>}),
ejabberd_config:may_hide_data(ip_to_string(Source))]),
send_welcome_message(JID),
send_registration_notifications(?MODULE, JID, Source);
{error, invalid_jid = Why} ->
{error, xmpp:err_jid_malformed(format_error(Why), Lang)};
{error, eaccess = Why} ->
{error, xmpp:err_forbidden(format_error(Why), Lang)};
{error, wait = Why} ->
{error, xmpp:err_resource_constraint(format_error(Why), Lang)};
{error, weak_password = Why} ->
{error, xmpp:err_not_acceptable(format_error(Why), Lang)};
{error, invalid_password = Why} ->
{error, xmpp:err_not_acceptable(format_error(Why), Lang)};
{error, not_allowed = Why} ->
{error, xmpp:err_not_allowed(format_error(Why), Lang)};
{error, exists = Why} ->
{error, xmpp:err_conflict(format_error(Why), Lang)};
{error, db_failure = Why} ->
{error, xmpp:err_internal_server_error(format_error(Why), Lang)}
end.
format_error(invalid_jid) ->
?T("Malformed username");
format_error(eaccess) ->
?T("Access denied by service policy");
format_error(wait) ->
?T("Users are not allowed to register accounts so quickly");
format_error(weak_password) ->
?T("The password is too weak");
format_error(invalid_password) ->
?T("The password contains unacceptable characters");
format_error(not_allowed) ->
?T("Not allowed");
format_error(exists) ->
?T("User already exists");
format_error(db_failure) ->
?T("Database failure");
format_error(Unexpected) ->
list_to_binary(io_lib:format(?T("Unexpected error condition: ~p"), [Unexpected])).
send_welcome_message(JID) ->
Host = JID#jid.lserver,
case mod_register_opt:welcome_message(Host) of
{<<"">>, <<"">>} -> ok;
{Subj, Body} ->
ejabberd_router:route(
#message{from = jid:make(Host),
to = JID,
subject = xmpp:mk_text(Subj),
body = xmpp:mk_text(Body)})
end.
send_registration_notifications(Mod, UJID, Source) ->
Host = UJID#jid.lserver,
case mod_register_opt:registration_watchers(Host) of
[] -> ok;
JIDs when is_list(JIDs) ->
Body =
(str:format("[~s] The account ~s was registered from "
"IP address ~s on node ~w using ~p.",
[get_time_string(),
jid:encode(UJID),
ejabberd_config:may_hide_data(
ip_to_string(Source)),
node(), Mod])),
lists:foreach(
fun(JID) ->
ejabberd_router:route(
#message{from = jid:make(Host),
to = JID,
type = chat,
body = xmpp:mk_text(Body)})
end, JIDs)
end.
check_from(#jid{user = <<"">>, server = <<"">>},
_Server) ->
allow;
check_from(JID, Server) ->
Access = mod_register_opt:access_from(Server),
acl:match_rule(Server, Access, JID).
check_timeout(undefined) -> true;
check_timeout(Source) ->
Timeout = ejabberd_option:registration_timeout(),
if is_integer(Timeout) ->
Priority = -erlang:system_time(millisecond),
CleanPriority = Priority + Timeout,
F = fun () ->
Treap = case mnesia:read(mod_register_ip, treap, write)
of
[] -> treap:empty();
[{mod_register_ip, treap, T}] -> T
end,
Treap1 = clean_treap(Treap, CleanPriority),
case treap:lookup(Source, Treap1) of
error ->
Treap2 = treap:insert(Source, Priority, [],
Treap1),
mnesia:write({mod_register_ip, treap, Treap2}),
true;
{ok, _, _} ->
mnesia:write({mod_register_ip, treap, Treap1}),
false
end
end,
case mnesia:transaction(F) of
{atomic, Res} -> Res;
{aborted, Reason} ->
?ERROR_MSG("timeout check error: ~p~n", [Reason]),
true
end;
true -> true
end.
clean_treap(Treap, CleanPriority) ->
case treap:is_empty(Treap) of
true -> Treap;
false ->
{_Key, Priority, _Value} = treap:get_root(Treap),
if Priority > CleanPriority ->
clean_treap(treap:delete_root(Treap), CleanPriority);
true -> Treap
end
end.
remove_timeout(undefined) -> true;
remove_timeout(Source) ->
Timeout = ejabberd_option:registration_timeout(),
if is_integer(Timeout) ->
F = fun () ->
Treap = case mnesia:read(mod_register_ip, treap, write)
of
[] -> treap:empty();
[{mod_register_ip, treap, T}] -> T
end,
Treap1 = treap:delete(Source, Treap),
mnesia:write({mod_register_ip, treap, Treap1}),
ok
end,
case mnesia:transaction(F) of
{atomic, ok} -> ok;
{aborted, Reason} ->
?ERROR_MSG("Mod_register: timeout remove error: "
"~p~n",
[Reason]),
ok
end;
true -> ok
end.
ip_to_string({_, _, _} = USR) ->
jid:encode(USR);
ip_to_string(Source) when is_tuple(Source) ->
misc:ip_to_list(Source);
ip_to_string(undefined) -> <<"undefined">>;
ip_to_string(_) -> <<"unknown">>.
get_time_string() -> write_time(erlang:localtime()).
%% Function copied from ejabberd_logger_h.erl and customized
write_time({{Y, Mo, D}, {H, Mi, S}}) ->
io_lib:format("~w-~.2.0w-~.2.0w ~.2.0w:~.2.0w:~.2.0w",
[Y, Mo, D, H, Mi, S]).
process_xdata_submit(X) ->
case {xmpp_util:get_xdata_values(<<"username">>, X),
xmpp_util:get_xdata_values(<<"password">>, X)} of
{[User], [Pass]} -> {ok, User, Pass};
_ -> error
end.
is_strong_password(Server, Password) ->
case jid:resourceprep(Password) of
PP when is_binary(PP) ->
is_strong_password2(Server, Password);
error ->
error_preparing_password
end.
is_strong_password2(Server, Password) ->
LServer = jid:nameprep(Server),
case mod_register_opt:password_strength(LServer) of
0 ->
true;
Entropy ->
ejabberd_auth:entropy(Password) >= Entropy
end.
%%%
%%% ip_access management
%%%
may_remove_resource({_, _, _} = From) ->
jid:remove_resource(From);
may_remove_resource(From) -> From.
get_ip_access(Host) ->
mod_register_opt:ip_access(Host).
check_ip_access({User, Server, Resource}, IPAccess) ->
case ejabberd_sm:get_user_ip(User, Server, Resource) of
{IPAddress, _PortNumber} ->
check_ip_access(IPAddress, IPAccess);
_ ->
deny
end;
check_ip_access(undefined, _IPAccess) ->
deny;
check_ip_access(IPAddress, IPAccess) ->
acl:match_rule(global, IPAccess, IPAddress).
check_access(User, Server, Source) ->
JID = jid:make(User, Server),
Access = mod_register_opt:access(Server),
IPAccess = get_ip_access(Server),
case acl:match_rule(Server, Access, JID) of
allow -> check_ip_access(Source, IPAccess);
deny -> deny
end.
mod_opt_type(access) ->
econf:acl();
mod_opt_type(access_from) ->
econf:acl();
mod_opt_type(access_remove) ->
econf:acl();
mod_opt_type(captcha_protected) ->
econf:bool();
mod_opt_type(ip_access) ->
econf:acl();
mod_opt_type(password_strength) ->
econf:number(0);
mod_opt_type(registration_watchers) ->
econf:list(econf:jid());
mod_opt_type(welcome_message) ->
econf:and_then(
econf:options(
#{subject => econf:binary(),
body => econf:binary()}),
fun(Opts) ->
{proplists:get_value(subject, Opts, <<>>),
proplists:get_value(body, Opts, <<>>)}
end);
mod_opt_type(redirect_url) ->
econf:url().
-spec mod_options(binary()) -> [{welcome_message, {binary(), binary()}} |
{atom(), term()}].
mod_options(_Host) ->
[{access, all},
{access_from, none},
{access_remove, all},
{captcha_protected, false},
{ip_access, all},
{password_strength, 0},
{registration_watchers, []},
{redirect_url, undefined},
{welcome_message, {<<>>, <<>>}}].
mod_doc() ->
#{desc =>
[?T("This module adds support for https://xmpp.org/extensions/xep-0077.html"
"[XEP-0077: In-Band Registration]. "
"This protocol enables end users to use a XMPP client to:"), "",
?T("* Register a new account on the server."), "",
?T("* Change the password from an existing account on the server."), "",
?T("* Delete an existing account on the server."), "",
?T("This module reads also another option defined globally for the "
"server: 'registration_timeout'. Please check that option "
"documentation in the section with top-level options.")],
opts =>
[{access,
#{value => ?T("AccessName"),
desc =>
?T("Specify rules to restrict what usernames can be registered. "
"If a rule returns 'deny' on the requested username, "
"registration of that user name is denied. There are no "
"restrictions by default.")}},
{access_from,
#{value => ?T("AccessName"),
desc =>
?T("By default, 'ejabberd' doesn't allow to register new accounts "
"from s2s or existing c2s sessions. You can change it by defining "
"access rule in this option. Use with care: allowing registration "
"from s2s leads to uncontrolled massive accounts creation by rogue users.")}},
{access_remove,
#{value => ?T("AccessName"),
desc =>
?T("Specify rules to restrict access for user unregistration. "
"By default any user is able to unregister their account.")}},
{captcha_protected,
#{value => "true | false",
desc =>
?T("Protect registrations with CAPTCHA (see section "
"https://docs.ejabberd.im/admin/configuration/#captcha[CAPTCHA] "
"of the Configuration Guide). The default is 'false'.")}},
{ip_access,
#{value => ?T("AccessName"),
desc =>
?T("Define rules to allow or deny account registration depending "
"on the IP address of the XMPP client. The 'AccessName' should "
"be of type 'ip'. The default value is 'all'.")}},
{password_strength,
#{value => "Entropy",
desc =>
?T("This option sets the minimum "
"https://en.wikipedia.org/wiki/Entropy_(information_theory)"
"[Shannon entropy] for passwords. The value 'Entropy' is a "
"number of bits of entropy. The recommended minimum is 32 bits. "
"The default is 0, i.e. no checks are performed.")}},
{registration_watchers,
#{value => "[JID, ...]",
desc =>
?T("This option defines a list of JIDs which will be notified each "
"time a new account is registered.")}},
{redirect_url,
#{value => ?T("URL"),
desc =>
?T("This option enables registration redirection as described in "
"https://xmpp.org/extensions/xep-0077.html#redirect"
"[XEP-0077: In-Band Registration: Redirection].")}},
{welcome_message,
#{value => "{subject: Subject, body: Body}",
desc =>
?T("Set a welcome message that is sent to each newly registered account. "
"The message will have subject 'Subject' and text 'Body'.")}}]}.
