From dab4c0cc107d8e829f2e68fa37605fa07b26f831 Mon Sep 17 00:00:00 2001
From: Badlop <badlop@process-one.net>
Date: Fri, 3 Dec 2021 12:16:20 +0100
Subject: [PATCH] New allow_modules option to restrict registration modules

---
 src/mod_register.erl     | 26 ++++++++++++++++++++++----
 src/mod_register_web.erl |  2 +-
 2 files changed, 23 insertions(+), 5 deletions(-)

diff --git a/src/mod_register.erl b/src/mod_register.erl
index 379318da6..0bb0978ef 100644
--- a/src/mod_register.erl
+++ b/src/mod_register.erl
@@ -32,11 +32,13 @@
 -behaviour(gen_mod).
 
 -export([start/2, stop/1, reload/3, stream_feature_register/2,
-	 c2s_unauthenticated_packet/2, try_register/4,
+	 c2s_unauthenticated_packet/2, try_register/4, try_register/5,
 	 process_iq/1, send_registration_notifications/3,
 	 mod_opt_type/1, mod_options/1, depends/2,
 	 format_error/1, mod_doc/0]).
 
+-deprecated({try_register, 4}).
+
 -include("logger.hrl").
 -include_lib("xmpp/include/xmpp.hrl").
 -include("translate.hrl").
@@ -283,7 +285,7 @@ try_register_or_set_password(User, Server, Password,
 	_ when CaptchaSucceed ->
 	    case check_from(From, Server) of
 		allow ->
-		    case try_register(User, Server, Password, Source, Lang) of
+		    case try_register(User, Server, Password, Source, ?MODULE, Lang) of
 			ok ->
 			    xmpp:make_iq_result(IQ);
 			{error, Error} ->
@@ -328,6 +330,13 @@ try_set_password(User, Server, Password, #iq{lang = Lang, meta = M} = IQ) ->
 	    xmpp:make_error(IQ, xmpp:err_internal_server_error(format_error(Why), Lang))
     end.
 
+try_register(User, Server, Password, SourceRaw, Module) ->
+    Modules = mod_register_opt:allow_modules(Server),
+    case (Modules == all) orelse lists:member(Module, Modules) of
+        true -> try_register(User, Server, Password, SourceRaw);
+        false -> {error, eaccess}
+    end.
+
 try_register(User, Server, Password, SourceRaw) ->
     case jid:is_nodename(User) of
 	false ->
@@ -363,8 +372,8 @@ try_register(User, Server, Password, SourceRaw) ->
 	    end
     end.
 
-try_register(User, Server, Password, SourceRaw, Lang) ->
-    case try_register(User, Server, Password, SourceRaw) of
+try_register(User, Server, Password, SourceRaw, Module, Lang) ->
+    case try_register(User, Server, Password, SourceRaw, Module) of
 	ok ->
 	    JID = jid:make(User, Server),
 	    Source = may_remove_resource(SourceRaw),
@@ -597,6 +606,8 @@ mod_opt_type(access_from) ->
     econf:acl();
 mod_opt_type(access_remove) ->
     econf:acl();
+mod_opt_type(allow_modules) ->
+    econf:either(all, econf:list(econf:atom()));
 mod_opt_type(captcha_protected) ->
     econf:bool();
 mod_opt_type(ip_access) ->
@@ -623,6 +634,7 @@ mod_options(_Host) ->
     [{access, all},
      {access_from, none},
      {access_remove, all},
+     {allow_modules, all},
      {captcha_protected, false},
      {ip_access, all},
      {password_strength, 0},
@@ -661,6 +673,12 @@ mod_doc() ->
               desc =>
                   ?T("Specify rules to restrict access for user unregistration. "
                      "By default any user is able to unregister their account.")}},
+           {allow_modules,
+            #{value => "all | [Module, ...]",
+              desc =>
+                  ?T("List of modules that can register accounts, or 'all'. "
+                     "The default value is 'all', which is equivalent to "
+                     "something like '[mod_register, mod_register_web]'.")}},
            {captcha_protected,
             #{value => "true | false",
               desc =>
diff --git a/src/mod_register_web.erl b/src/mod_register_web.erl
index 1ac3b58dc..0cf4bcff8 100644
--- a/src/mod_register_web.erl
+++ b/src/mod_register_web.erl
@@ -521,7 +521,7 @@ register_account(Username, Host, Password, Ip) ->
     end.
 
 register_account2(Username, Host, Password, Ip) ->
-    case mod_register:try_register(Username, Host, Password, Ip)
+    case mod_register:try_register(Username, Host, Password, Ip, ?MODULE)
 	of
       ok ->
 	  {success, ok, {Username, Host, Password}};