1/* Part of SWISH 2 3 Author: Jan Wielemaker 4 E-mail: J.Wielemaker@cs.vu.nl 5 WWW: http://www.swi-prolog.org 6 Copyright (C): 2017, VU University Amsterdam 7 CWI Amsterdam 8 All rights reserved. 9 10 Redistribution and use in source and binary forms, with or without 11 modification, are permitted provided that the following conditions 12 are met: 13 14 1. Redistributions of source code must retain the above copyright 15 notice, this list of conditions and the following disclaimer. 16 17 2. Redistributions in binary form must reproduce the above copyright 18 notice, this list of conditions and the following disclaimer in 19 the documentation and/or other materials provided with the 20 distribution. 21 22 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 23 "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 24 LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 25 FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 26 COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 27 INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 28 BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 29 LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 30 CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN 32 ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 33 POSSIBILITY OF SUCH DAMAGE. 34*/ 35 36:- module(swish_pep, 37 [ authorized/2, % +Action, +Options 38 ws_authorized/2 % +Action, +WSID 39 ]). 40:- use_module(library(debug)). 41:- use_module(library(option)). 42:- use_module(library(error)). 43:- use_module(library(http/http_wrapper)). 44 45:- use_module(authenticate). 46:- use_module(storage). 47:- use_module(config). 48 49/** <module> SWISH PEP (Policy Enforcement Point) 50 51This module implements the _Policy Enforcement Point_. It is called by 52modules that perform operations that may not be publically accessible. 53Examples are: 54 55 - Access to files (download, create, update, delete, list, search) 56 - Control of the sandboxing 57 - Access to users (profile management) 58*/ 59 60:- multifile 61 swish_config:approve/3. 62 63%! authorized(+Action, +Options) is det. 64% 65% Verify that Action is authorized. Options: 66% 67% - indentity(+Identity) 68% Indentity is the identity dict as collected by autenticate.pl. 69% 70% Actions defined: 71% 72% * Gitty store actions 73% - gitty(download(Obj, Format)) 74% Attempt to download Obj, one of file(File) or hash(Hash) in 75% Format, see storage_get/4 from storage.pl 76% - gitty(create(File,Named,Meta)) 77% Create file name File with the given meta-data. Named is one 78% of `named` or `random` and indicates whether the file is named 79% by the user or the name is generated by the system. 80% - gitty(update(File,PrevMeta,Meta)) 81% Update File and change meta-data from PrevMeta to Meta. 82% - gitty(delete(File,Meta)) 83% Delete File that has the given meta data. 84% * File actions 85% - file(update(File,Meta)) 86% Update (save) a physical file outside the versioned gitty 87% store. 88% * Social options 89% - chat(open) 90% Open websocket chat channel 91% - chat(post(Message, About)) 92% Post a chat message about a specific topic 93% 94% @throws http_reply(forbidden(URL)) if the action is not allowed. Can 95% we generate a JSON error object? 96 (Action, _Options) :- 98 var(Action), 99 !, 100 instantiation_error(Action). 101authorized(Action, Options) :- 102 option(identity(Id), Options), 103 ( authorize(Action, Id) 104 -> debug(pep, 'Approved gitty action ~p to ~p', [Action, Id]) 105 ; debug(pep, 'Denied action ~p to ~p', [Action, Id]), 106 http_current_request(Request), 107 option(path(Path), Request), 108 throw(http_reply(forbidden(Path))) 109 ). 110 111%! ws_authorized(+Action, +WSUser) is semidet. 112% 113% True when WSUser is allowed to perform action. WSUser is a dict 114% containing the user info as provided by chat:chat_add_user_id/3. It 115% notably has a key `profile_id` if the user is logged on. 116% 117% @tbd Generalise. Notably, how do we get the identity as 118% authenticate/2 returns? 119 (Action, _WSUser) :- 121 var(Action), 122 !, 123 instantiation_error(Action). 124ws_authorized(chat(post(_,_)), WSUser) :- 125 _Profile = WSUser.get(profile_id). 126 127 128:- multifile 129 approve/2, 130 deny/2. 131 (Action, Id) :- 133 swish_config:approve(Action, Id, Approve), 134 !, 135 Approve == true. 136authorize(Action, Id) :- 137 approve(Action, Id), !, 138 \+ deny(Action, Id). 139 140%! approve(+Action, +Id) 141 142approve(gitty(update(_File,PrevMeta,_Meta)), Auth) :- !, 143 storage_meta_property(PrevMeta, modify(Modify)), 144 ( memberchk(any, Modify) 145 -> true 146 ; memberchk(login, Modify) 147 -> user_property(Auth, login(_)) 148 ; storage_meta_property(PrevMeta, identity(Id)), 149 user_property(Auth, identity(Id)) 150 ). 151approve(gitty(_), _). 152approve(file(update(_File, _Meta)), Auth) :- 153 user_property(Auth, login(local)). 154approve(run(any, _), Auth) :- 155 user_property(Auth, login(local)). 156approve(chat(open), _). 157 158%! deny(+Action, +Id) 159 160%! swish_config:approve(+Action, +Identity, -Approve) is semidet. 161% 162% This hook is called by approve/2 and deny/2 before the default 163% rules. If this hook succeeds it must unify Approve with `true` 164% or `false`. Action is approved if Approve is `true`. 165 166 167 168 /******************************* 169 * PENGINES * 170 *******************************/ 171 172%! pengines:not_sandboxed(+User, +Application) is semidet. 173% 174% Called by Pengines to see whether User may call non-sandboxed 175% operations in Application. 176 177:- multifile pengines:not_sandboxed/2. 178 179penginesnot_sandboxed(User, Application) :- 180 authorized(run(any, Application), [identity(User)])