/* Part of SWISH Author: Jan Wielemaker E-mail: J.Wielemaker@cs.vu.nl WWW: http://www.swi-prolog.org Copyright (C): 2017, VU University Amsterdam CWI Amsterdam All rights reserved. Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: 1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. 2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ :- module(config_auth_stackoverflow, []). :- use_module(swish(lib/oauth2)). :- use_module(swish(lib/plugin/login)). :- use_module(library(http/http_open)). :- use_module(library(http/http_dispatch)). :- use_module(library(http/http_header)). :- use_module(library(http/http_session)). :- use_module(library(http/http_json)). :- use_module(library(http/json)). :- use_module(library(http/http_path)). :- use_module(library(uri)). :- use_module(library(debug)). :- use_module(library(apply)). /** Enable login with stackexchange This module allows for configures _login with Stack exchange. To enable this module: 1. Follow these [steps](https://api.stackexchange.com/docs/authentication) to register your application on Stack Apps. Get the following info: - The client ID - The client secret - The key - Register a redirect url. To test from localhost, this should be =|http://localhost:3050/oauth2/stackexchange/reply|= 2. COPY this file to =config-enabled= 3. EDIT the server attributes */ :- multifile oauth2:login/3, oauth2:server_attribute/3, swish_config:login_item/2, % -Server, -HTML_DOM swish_config:login/2, % +Server, +Request swish_config:user_info/2. % +Request, ?Server, -Info :- http_set_session_options([create(noauto)]). :- http_handler(swish(logout), stackexchange_logout, []). %! oauth2:server_attribute(?ServerID, ?Attribute, ?Value) % % Declare properties of an oauth2 identity provider. The values below % are for [StackExchange](http://stackexchange.com/) server. % % EDIT: % - url: base URL of the stackexchange authentication server % - api_endpoint: Stack Apps API endpoint % - redirect_uri: our location % - client_id: Client Id from Stack Apps % - client_secret: Client Secret from Stack Apps % - key: Key from Stack Apps to access their API (/me) % - site: Stack exchange site for which to ask info % % @see swish(lib/oauth2) for a description of the attributes. oauth2:server_attribute(stackexchange, url, 'https://stackexchange.com'). oauth2:server_attribute(stackexchange, redirect_uri, 'http://localhost:3050/oauth2/stackexchange/reply'). oauth2:server_attribute(stackexchange, authorization_endpoint, '/oauth'). oauth2:server_attribute(stackexchange, token_endpoint, '/oauth/access_token'). oauth2:server_attribute(stackexchange, api_endpoint, 'https://api.stackexchange.com'). oauth2:server_attribute(stackexchange, client_id, '****'). oauth2:server_attribute(stackexchange, client_secret, '****'). oauth2:server_attribute(stackexchange, key, '****'). oauth2:server_attribute(stackexchange, site, 'stackoverflow'). oauth2:server_attribute(stackexchange, scope, ''). /******************************* * SWISH HOOKS * *******************************/ swish_config:login_item(stackexchange, 10-Item) :- http_absolute_location(icons('so-icon.png'), Img, []), Item = img([ src(Img), class('login-with'), 'data-server'(stackexchange), 'data-frame'(popup), title('Login with StackOverflow') ]). swish_config:login(stackexchange, Request) :- oauth2_login(Request, [server(stackexchange)]). oauth2:login(_Request, stackexchange, TokenInfo) :- debug(oauth, 'TokenInfo: ~p', [TokenInfo]), stackexchange_me(TokenInfo.access_token, Claim), debug(oauth, 'Claim: ~p', [Claim]), map_user_info(Claim, UserInfo), http_open_session(_SessionID, []), session_remove_user_data, http_session_assert(oauth2(stackexchange, TokenInfo)), http_session_assert(user_info(stackexchange, UserInfo)), reply_logged_in([ identity_provider('StackOverflow'), name(UserInfo.name), user_info(UserInfo) ]). %! stackexchange_me(+AccessToken, -Info) % % Stack exchange does not support the oauth2 `user_info` endpoint. % Instead, we must use the =/me= API. This is a little unlucky as we % need to duplicate some infrastructure from the generic oauth2.pl % module. stackexchange_me(AccessToken, Info) :- oauth2:server_attribute(stackexchange, api_endpoint, URLBase), oauth2:server_attribute(stackexchange, client_id, ClientID), oauth2:server_attribute(stackexchange, client_secret, ClientSecret), oauth2:server_attribute(stackexchange, key, Key), oauth2:server_attribute(stackexchange, site, Site), uri_extend(URLBase, '/2.2/me', [ key(Key), site(Site), access_token(AccessToken) ], URL), setup_call_cleanup( http_open(URL, In, [ authorization(basic(ClientID, ClientSecret)), header(content_type, ContentType), status_code(Code) ]), read_reply(Code, ContentType, In, Info0), close(In)), me_info(Info0, Info). me_info(Info, Me) :- [Me] = Info.get(items), !. me_info(Info, Info). read_reply(Code, ContentType, In, Dict) :- debug(oauth, '/me returned ~p ~p', [Code, ContentType]), http_parse_header_value(content_type, ContentType, Parsed), read_reply2(Code, Parsed, In, Dict). %! read_reply2(+Code, +ContentType, +Stream, -Dict) is det. % % Read the server reply as a dict. Normally, the reply is a JSON % object, but stackexchange seems to send it as a www-form-encoded % string. read_reply2(200, media(application/json, _Attributes), In, Dict) :- !, json_read_dict(In, Dict, [default_tag(#)]). read_reply2(Code, media(application/json, _Attributes), In, error{code:Code, details:Details}) :- !, json_read_dict(In, Details, [default_tag(#)]). read_reply2(Code, Type, In, error{code:Code, message:Reply}) :- debug(oauth(token), 'Got code ~w, type ~q', [Code, Type]), read_string(In, _, Reply). %! stackexchange_logout(+Request) % % Logout by removing the session data stackexchange_logout(_Request) :- catch(session_remove_user_data, _, true), reply_logged_out([]). %! swish_config:user_info(+Request, ?Server, -Info:dict) is semidet. % % True if Info represents describes the currently logged in user. swish_config:user_info(_Request, stackexchange, UserInfo) :- http_in_session(_SessionID), http_session_data(user_info(stackexchange, UserInfo)). %! map_user_info(+OAuthInfo, -UserInfo) is det. % % u{user:User, group:Group, name:Name, email:Email} map_user_info(Dict0, Dict) :- dict_pairs(Dict0, Tag, Pairs0), maplist(map_user_field, Pairs0, Pairs), http_link_to_id(stackexchange_logout, [], LogoutURL), dict_pairs(Dict, Tag, [ identity_provider-stackexchange, auth_method-oauth2, logout_url-LogoutURL | Pairs ]). map_user_field(display_name-Name, name-Name) :- !. map_user_field(profile_image-URL, picture-URL) :- !. map_user_field(link-URL, profile_url-URL) :- !. map_user_field(user_id-Id, external_identity-SId) :- !, format(string(SId), '~w', [Id]). map_user_field(Field, Field). session_remove_user_data :- http_session_retractall(oauth2(_,_)), http_session_retractall(user_info(_,_)). /******************************* * URI BASICS * *******************************/ %! uri_extend(+Base:atom, +Rel:atom, +Query:list, -URI:atom) is det. % % Create a URI from Base, A relative URI and a query. uri_extend(Base, Relative, Query, URI) :- uri_resolve(Relative, Base, URI0), uri_extend_query(URI0, Query, URI). %! uri_extend_query(+URI0:atom, +Query:list, -URI:atom) is det. % % Extend a URI with a query. If URI0 already has a query, keep all % parameters that do not conflict. uri_extend_query(URI0, Query, URI) :- uri_components(URI0, Components0), extend_query(Components0, Query, Query1), uri_data(search, Components0, Query1, Components1), uri_components(URI, Components1). extend_query(Components, QueryEx, Query) :- uri_data(search, Components, Query0), ( var(Query0) -> uri_query_components(Query, QueryEx) ; uri_query_components(Query0, Q0), merge_components(Q0, QueryEx, Q), uri_query_components(Query, Q) ). merge_components([], Q, Q). merge_components([N=_|T0], Q1, Q) :- memberchk(N=_, Q1), !, merge_components(T0, Q1, Q). merge_components([H|T0], Q1, [H|Q]) :- merge_components(T0, Q1, Q).