Add function to change the current user’s password

This function does not ask for the confirmation because this is an
user-facing issue, not for the database.

Still missing: validation and proper error messages.

deploy/change_password.sql

@@ -0,0 +1,28 @@
+-- Deploy numerus:change_password to pg
+-- requires: schema_numerus
+-- requires: user
+
+begin;
+
+set search_path to numerus, auth, public;
+
+create or replace function change_password(new_password text) returns void as
+$$
+update "user"
+set password = new_password
+where email = current_user_email()
+  and cookie = current_user_cookie()
+  and cookie_expires_at > current_timestamp
+  and length(cookie) > 30
+$$ language sql
+security definer
+set search_path to auth, numerus, pg_temp;
+
+revoke execute on function change_password(text) from public;
+grant execute on function change_password(text) to invoicer;
+grant execute on function change_password(text) to admin;
+
+comment on function change_password(text) is
+'Changes the password for the current app user';
+
+commit;

pkg/profile.go

@@ -43,6 +43,9 @@ func ProfileHandler() http.Handler {
 			page.Language = r.FormValue("language")
 			cookie := conn.MustGetText(r.Context(), "", "update user_profile set name = $1, email = $2, lang_tag = $3 returning build_cookie()", page.Name, page.Email, page.Language)
 			setSessionCookie(w, cookie)
+			if page.Password != "" && page.Password == page.PasswordConfirm {
+				conn.MustExec(r.Context(), "select change_password($1)", page.Password)
+			}
 			http.Redirect(w, r, "/profile", http.StatusSeeOther)
 			return
 		} else {

revert/change_password.sql

@@ -0,0 +1,7 @@
+-- Revert numerus:change_password from pg
+
+begin;
+
+drop function if exists numerus.change_password(text);
+
+commit;

sqitch.plan

@@ -23,3 +23,4 @@ logout [schema_auth current_user_email current_user_cookie user] 2023-01-17T19:1
 set_cookie [schema_public check_cookie] 2023-01-19T11:00:22Z jordi fita mas <jordi@tandem.blog> # Add function to set the role based on the cookie
 available_languages [schema_numerus language] 2023-01-21T21:11:08Z jordi fita mas <jordi@tandem.blog> # Add the initial available languages
 user_profile [schema_numerus user current_user_email current_user_cookie] 2023-01-21T23:18:20Z jordi fita mas <jordi@tandem.blog> # Add view for user profile
+change_password [schema_numerus user] 2023-01-23T20:22:45Z jordi fita mas <jordi@tandem.blog> # Add function to change the current user’s password

test/change_password.sql

@@ -0,0 +1,57 @@
+-- Test change_password
+set client_min_messages to warning;
+create extension if not exists pgtap;
+reset client_min_messages;
+
+begin;
+
+select plan(14);
+
+set search_path to numerus, auth, public;
+
+select has_function('numerus', 'change_password', array ['text']);
+select function_lang_is('numerus', 'change_password', array ['text'], 'sql');
+select function_returns('numerus', 'change_password', array ['text'], 'void');
+select is_definer('numerus', 'change_password', array ['text']);
+select volatility_is('numerus', 'change_password', array ['text'], 'volatile');
+select function_privs_are('numerus', 'change_password', array ['text'], 'guest', array []::text[]);
+select function_privs_are('numerus', 'change_password', array ['text'], 'invoicer', array ['EXECUTE']);
+select function_privs_are('numerus', 'change_password', array ['text'], 'admin', array ['EXECUTE']);
+select function_privs_are('numerus', 'change_password', array ['text'], 'authenticator', array []::text[]);
+
+set client_min_messages to warning;
+truncate auth."user" cascade;
+reset client_min_messages;
+
+insert into auth."user" (user_id, email, name, password, role, cookie, cookie_expires_at)
+values (1, 'demo@tandem.blog', 'Demo', 'test', 'invoicer', '44facbb30d8a419dfd4bfbc44a4b5539d4970148dfc84bed0e', current_timestamp + interval '1 month')
+     , (9, 'admin@tandem.blog', 'Demo', 'test', 'admin', '12af4c88b528c2ad4222e3740496ecbc58e76e26f087657524', current_timestamp + interval '1 month')
+;
+
+select lives_ok( $$ select change_password('another') $$, 'Should run even without current user' );
+
+select isnt_empty (
+	$$ select * from auth."user" where password = crypt('test', password) $$,
+	'Should not have changed any password'
+);
+
+select set_cookie('44facbb30d8a419dfd4bfbc44a4b5539d4970148dfc84bed0e/demo@tandem.blog');
+
+select lives_ok( $$ select change_password('another') $$, 'Should run with the correct user' );
+
+reset role;
+
+select isnt_empty (
+	$$ select * from auth."user" where email = 'demo@tandem.blog' and password = crypt('another', password) $$,
+	'Should have changed the password of the current user'
+);
+
+select isnt_empty (
+	$$ select * from auth."user" where email = 'admin@tandem.blog' and password = crypt('test', password) $$,
+	'Should not have changed any other password'
+);
+
+select *
+from finish();
+
+rollback;

verify/change_password.sql

@@ -0,0 +1,7 @@
+-- Verify numerus:change_password on pg
+
+begin;
+
+select has_function_privilege('numerus.change_password(text)', 'execute');
+
+rollback;