introduce defineContext replacing explicit "set local current..."

src/main/resources/db/changelog/010-context.sql

@@ -4,10 +4,24 @@
 -- ============================================================================
 --changeset context-DEFINE:1 endDelimiter:--//
 -- ----------------------------------------------------------------------------
+
+/*
+    Callback which is called after the context has been (re-) defined.
+    This function will be overwritten by later changesets.
+ */
+create procedure contextDefined(
+    currentTask varchar,
+    currentRequest varchar,
+    currentUser varchar,
+    assumedRoles varchar
+)
+    language plpgsql as $$
+begin
+end; $$;
+
 /*
     Defines the transaction context.
  */
-
 create or replace procedure defineContext(
     currentTask varchar,
     currentRequest varchar,
@@ -16,14 +30,18 @@ create or replace procedure defineContext(
 )
     language plpgsql as $$
 begin
-    raise notice 'currentRequest: %', defineContext.currentRequest;
     execute format('set local hsadminng.currentTask to %L', currentTask);
+
+    currentRequest := coalesce(currentRequest, '');
+    execute format('set local hsadminng.currentRequest to %L', currentRequest);
+
+    currentUser := coalesce(currentUser, '');
     execute format('set local hsadminng.currentUser to %L', currentUser);
-    if length(assumedRoles) > 0 then
-        execute format('set local hsadminng.assumedRoles to %L', assumedRoles);
-    else
-        execute format('set local hsadminng.assumedRoles to %L', '');
-    end if;
+
+    assumedRoles := coalesce(assumedRoles, '');
+    execute format('set local hsadminng.assumedRoles to %L', assumedRoles);
+
+    call contextDefined(currentTask, currentRequest, currentUser, assumedRoles);
 end; $$;
 --//
 
@@ -49,7 +67,7 @@ begin
             currentTask := null;
     end;
     if (currentTask is null or currentTask = '') then
-        raise exception '[401] hsadminng.currentTask must be defined, please use "SET LOCAL ...;"';
+        raise exception '[401] currentTask must be defined, please call `defineContext(...)`';
     end if;
     raise debug 'currentTask: %', currentTask;
     return currentTask;
@@ -61,8 +79,7 @@ end; $$;
 --changeset context-CURRENT-USER:1 endDelimiter:--//
 -- ----------------------------------------------------------------------------
 /*
-    Returns the current user as set by `hsadminng.currentUser`.
-    Raises exception if not set.
+    Returns the current user as defined by `defineContext(...)`.
  */
 create or replace function currentUser()
     returns varchar(63)
@@ -77,10 +94,6 @@ begin
         when others then
             currentUser := null;
     end;
-    if (currentUser is null or currentUser = '') then
-        raise exception '[401] hsadminng.currentUser must be defined, please use "SET LOCAL ...;"';
-    end if;
-    raise debug 'currentUser: %', currentUser;
     return currentUser;
 end; $$;
 --//

src/main/resources/db/changelog/051-rbac-user-grant.sql

@@ -9,15 +9,15 @@ create or replace function assumedRoleUuid()
     stable leakproof
     language plpgsql as $$
 declare
-    currentSubjectUuids uuid[];
+    currentSubjectsUuids uuid[];
 begin
     -- exactly one role must be assumed, not none not more than one
     if cardinality(assumedRoles()) <> 1 then
         raise exception '[400] Granting roles to user is only possible if exactly one role is assumed, given: %', assumedRoles();
     end if;
 
-    currentSubjectUuids := currentSubjectsUuids();
-    return currentSubjectUuids[1];
+    currentSubjectsUuids := currentSubjectsUuids();
+    return currentSubjectsUuids[1];
 end; $$;
 
 create or replace procedure grantRoleToUserUnchecked(grantedByRoleUuid uuid, roleUuid uuid, userUuid uuid, doAssume boolean = true)

src/main/resources/db/changelog/054-rbac-context.sql

@@ -1,45 +1,32 @@
 --liquibase formatted sql
 
--- ============================================================================
---changeset rbac-context-CURRENT-USER-ID:1 endDelimiter:--//
--- ----------------------------------------------------------------------------
-/*
-    Returns the id of the current user as set by `hsadminng.currentUser`.
-    Raises exception if not set.
- */
 
-create or replace function currentUserUuid()
+-- ============================================================================
+--changeset rbac-context-DETERMINE:1 endDelimiter:--//
+-- ----------------------------------------------------------------------------
+
+create or replace function determineCurrentUserUuid(currentUser varchar)
     returns uuid
     stable leakproof
     language plpgsql as $$
 declare
-    currentUser   varchar(63);
     currentUserUuid uuid;
 begin
-    currentUser := currentUser();
-    currentUserUuid = (select uuid from RbacUser where name = currentUser);
-    if currentUserUuid is null then
-        raise exception '[401] hsadminng.currentUser defined as %, but does not exists', currentUser;
+    if currentUser = '' then
+        return null;
     end if;
+
+    select uuid from RbacUser where name = currentUser into currentUserUuid;
+    -- TODO: maybe this should be changed, and in this case no user name defined in context?
+    -- no exception if user does not exist because users can register themselves
     return currentUserUuid;
 end; $$;
---//
 
--- ============================================================================
---changeset rbac-context-CURRENT-SUBJECT-IDS:1 endDelimiter:--//
--- ----------------------------------------------------------------------------
-/*
-    Returns id of current user as set in `hsadminng.currentUser`
-    or, if any, ids of assumed role names as set in `hsadminng.assumedRoles`
-    or empty array, if not set.
- */
-create or replace function currentSubjectsUuids()
+create or replace function determineCurrentSubjectsUuids(currentUserUuid uuid, assumedRoles varchar)
     returns uuid[]
     stable leakproof
     language plpgsql as $$
 declare
-    currentUserUuid       uuid;
-    roleNames           varchar(63)[];
     roleName            varchar(63);
     objectTableToAssume varchar(63);
     objectNameToAssume  varchar(63);
@@ -48,19 +35,18 @@ declare
     roleIdsToAssume     uuid[];
     roleUuidToAssume    uuid;
 begin
-    currentUserUuid := currentUserUuid();
     if currentUserUuid is null then
-        raise exception '[401] user % does not exist', currentUser();
+        if  length(coalesce(assumedRoles, '')) > 0 then
+            raise exception '[403] undefined has no permission to assume role %', assumedRoles;
+        else
+            return array[]::uuid[];
+        end if;
     end if;
-
-    roleNames := assumedRoles();
-    if cardinality(roleNames) = 0 then
+    if  length(coalesce(assumedRoles, '')) = 0 then
         return array [currentUserUuid];
     end if;
 
-    raise notice 'assuming roles: %', roleNames;
-
-    foreach roleName in array roleNames
+    foreach roleName in array string_to_array(assumedRoles, ';')
         loop
             roleName = overlay(roleName placing '#' from length(roleName) + 1 - strpos(reverse(roleName), '.'));
             objectTableToAssume = split_part(roleName, '#', 1);
@@ -69,19 +55,117 @@ begin
 
             objectUuidToAssume = findObjectUuidByIdName(objectTableToAssume, objectNameToAssume);
 
-            -- TODO: either the result needs to be cached at least per transaction or we need to get rid of SELCT in a loop
             select uuid as roleuuidToAssume
                 from RbacRole r
                 where r.objectUuid = objectUuidToAssume
                   and r.roleType = roleTypeToAssume
                 into roleUuidToAssume;
             if (not isGranted(currentUserUuid, roleUuidToAssume)) then
-                raise exception '[403] user % (%) has no permission to assume role % (%)', currentUser(), currentUserUuid, roleName, roleUuidToAssume;
+                raise exception '[403] user % has no permission to assume role %', currentUser(), roleName;
             end if;
             roleIdsToAssume := roleIdsToAssume || roleUuidToAssume;
         end loop;
 
     return roleIdsToAssume;
 end; $$;
+
+-- ============================================================================
+--changeset rbac-context-CONTEXT-DEFINED:1 endDelimiter:--//
+-- ----------------------------------------------------------------------------
+/*
+    Callback which is called after the context has been (re-) defined.
+    This function will be overwritten by later changesets.
+ */
+create or replace procedure contextDefined(
+    currentTask varchar,
+    currentRequest varchar,
+    currentUser varchar,
+    assumedRoles varchar
+)
+    language plpgsql as $$
+declare
+    currentUserUuid uuid;
+begin
+    execute format('set local hsadminng.currentTask to %L', currentTask);
+
+    execute format('set local hsadminng.currentRequest to %L', currentRequest);
+
+    execute format('set local hsadminng.currentUser to %L', currentUser);
+    select determineCurrentUserUuid(currentUser) into currentUserUuid;
+    execute format('set local hsadminng.currentUserUuid to %L', coalesce(currentUserUuid::text, ''));
+
+    execute format('set local hsadminng.assumedRoles to %L', assumedRoles);
+    execute format('set local hsadminng.currentSubjectsUuids to %L',
+       (select array_to_string(determinecurrentSubjectsUuids(currentUserUuid, assumedRoles), ';')));
+
+    raise notice 'Context defined as: %, %, %, [%]', currentTask, currentRequest, currentUser, assumedRoles;
+end; $$;
+
+
+-- ============================================================================
+--changeset rbac-context-CURRENT-USER-ID:1 endDelimiter:--//
+-- ----------------------------------------------------------------------------
+/*
+    Returns the uuid of the current user as set via `defineContext(...)`.
+ */
+
+create or replace function currentUserUuid()
+    returns uuid
+    stable leakproof
+    language plpgsql as $$
+declare
+    currentUserUuid text;
+    currentUserName text;
+begin
+    begin
+        currentUserUuid := current_setting('hsadminng.currentUserUuid');
+    exception
+        when others then
+            currentUserUuid := null;
+    end;
+    if (currentUserUuid is null or currentUserUuid = '') then
+        currentUserName := currentUser();
+        if (length(currentUserName) > 0) then
+            raise exception '[401] currentUserUuid cannot be determined, unknown user name "%"', currentUserName;
+        else
+            raise exception '[401] currentUserUuid cannot be determined, please call `defineContext(...)` first;"';
+        end if;
+    end if;
+    return currentUserUuid::uuid;
+end; $$;
+--//
+
+-- ============================================================================
+--changeset rbac-context-CURRENT-SUBJECT-UUIDS:1 endDelimiter:--//
+-- ----------------------------------------------------------------------------
+/*
+    Returns the uuid of the current user as set via `defineContext(...)`,
+    or, if any, the uuids of all assumed roles as set via `defineContext(...)`
+    or empty array, if context is not defined.
+ */
+create or replace function currentSubjectsUuids()
+    returns uuid[]
+    stable leakproof
+    language plpgsql as $$
+declare
+    currentSubjectsUuids text;
+    currentUserName text;
+begin
+    begin
+        currentSubjectsUuids := current_setting('hsadminng.currentSubjectsUuids');
+    exception
+        when others then
+            currentSubjectsUuids := null;
+    end;
+    if (currentSubjectsUuids is null or length(currentSubjectsUuids) = 0 ) then
+        currentUserName := currentUser();
+        if (length(currentUserName) > 0) then
+            raise exception '[401] currentUserUuid cannot be determined, unknown user name "%"', currentUserName;
+        else
+            raise exception '[401] currentSubjectsUuids cannot be determined, please call `defineContext(...)` first;"';
+        end if;
+    end if;
+    return string_to_array(currentSubjectsUuids, ';');
+end; $$;
 --//
 

src/main/resources/db/changelog/100-hs-base.sql

@@ -21,12 +21,13 @@ grant select on global to restricted;
 /**
   A single row to be referenced as a global object.
  */
-set local hsadminng.currentUser to 'init';
-set local hsadminng.currentTask to 'initializing table "global"';
-insert
-    into RbacObject (objecttable) values ('global');
-insert
-    into Global (uuid, name) values ((select uuid from RbacObject where objectTable = 'global'), 'hostsharing');
+begin transaction;
+    call defineContext('initializing table "global"', null, null, null);
+    insert
+        into RbacObject (objecttable) values ('global');
+    insert
+        into Global (uuid, name) values ((select uuid from RbacObject where objectTable = 'global'), 'hostsharing');
+commit;
 --//
 
 
@@ -40,8 +41,7 @@ create or replace function hasGlobalPermission(op RbacOp)
 $$
     -- TODO: this could to be optimized
 select (select uuid from global) in
-       (select queryAccessibleObjectUuidsOfSubjectIds(
-                   op, 'global', currentSubjectsUuids()));
+       (select queryAccessibleObjectUuidsOfSubjectIds(op, 'global', currentSubjectsUuids()));
 $$;
 --//
 
@@ -94,9 +94,10 @@ create or replace function hostsharingAdmin()
 select 'global', (select uuid from RbacObject where objectTable = 'global'), 'admin'::RbacRoleType;
 $$;
 
-set local hsadminng.currentUser to 'init';
-set local hsadminng.currentTask to 'creating Hostsharing admin role';
-select createRole(hostsharingAdmin());
+begin transaction;
+    call defineContext('creating Hostsharing admin role', null, null, null);
+    select createRole(hostsharingAdmin());
+commit;
 
 -- ============================================================================
 --changeset hs-base-ADMIN-USERS:1 context:dev,tc endDelimiter:--//
@@ -108,8 +109,7 @@ do language plpgsql $$
     declare
         admins uuid ;
     begin
-        set local hsadminng.currentUser to 'init';
-        set local hsadminng.currentTask to 'creating fake Hostsharing admin users';
+        call defineContext('creating fake Hostsharing admin users', null, null, null);
 
         admins = findRoleId(hostsharingAdmin());
         call grantRoleToUserUnchecked(admins, admins, createRbacUser('mike@hostsharing.net'));
@@ -131,13 +131,13 @@ do language plpgsql $$
     declare
         userName varchar;
     begin
-        set local hsadminng.currentUser = 'sven@hostsharing.net';
+        call defineContext('testing currentUserUuid', null, 'sven@hostsharing.net', null);
         select userName from RbacUser where uuid = currentUserUuid() into userName;
         if userName <> 'sven@hostsharing.net' then
             raise exception 'setting or fetching initial currentUser failed, got: %', userName;
         end if;
 
-        set local hsadminng.currentUser = 'mike@hostsharing.net';
+        call defineContext('testing currentUserUuid', null, 'mike@hostsharing.net', null);
         select userName from RbacUser where uuid = currentUserUuid() into userName;
         if userName = 'mike@hostsharing.net' then
             raise exception 'currentUser should not change in one transaction, but did change, got: %', userName;

src/main/resources/db/changelog/113-hs-customer-rbac.sql

@@ -206,8 +206,7 @@ do language plpgsql $$
         hostsharingObjectUuid  uuid;
         hsAdminRoleUuid        uuid ;
     begin
-        set local hsadminng.currentUser to 'init';
-        set local hsadminng.currentTask to 'granting global add-customer permission to Hostsharing admin role';
+        call defineContext('granting global add-customer permission to Hostsharing admin role', null, null, null);
 
         hsAdminRoleUuid := findRoleId(hostsharingAdmin());
         hostsharingObjectUuid := (select uuid from global);
@@ -224,7 +223,8 @@ create or replace function addCustomerNotAllowedForCurrentSubjects()
     language PLPGSQL
 as $$
 begin
-    raise exception '[403] add-customer not permitted for %', array_to_string(currentSubjects(), ';', 'null');
+    raise exception '[403] add-customer not permitted for %',
+        array_to_string(currentSubjects(), ';', 'null');
 end; $$;
 
 /**

src/main/resources/db/changelog/118-hs-customer-test-data.sql

@@ -30,8 +30,7 @@ declare
     custAdminName varchar;
 begin
     currentTask = 'creating RBAC test customer #' || custReference || '/' || custPrefix;
-    set local hsadminng.currentUser to 'mike@hostsharing.net';
-    set local hsadminng.assumedRoles to 'global#hostsharing.admin';
+    call defineContext(currentTask, null, 'mike@hostsharing.net', 'global#hostsharing.admin');
     execute format('set local hsadminng.currentTask to %L', currentTask);
 
     custRowId = uuid_generate_v4();
@@ -53,8 +52,6 @@ create or replace procedure createCustomerTestData(
 )
     language plpgsql as $$
 begin
-    set hsadminng.currentUser to '';
-
     for t in startCount..endCount
         loop
             call createCustomerTestData(testCustomerReference(t), intToVarChar(t, 3));

src/main/resources/db/changelog/128-hs-package-test-data.sql

@@ -26,9 +26,7 @@ begin
 
             custAdminUser = 'customer-admin@' || cust.prefix || '.example.com';
             custAdminRole = 'customer#' || cust.prefix || '.admin';
-            execute format('set local hsadminng.currentUser to %L', custAdminUser);
-            execute format('set local hsadminng.assumedRoles to %L', custAdminRole);
-            execute format('set local hsadminng.currentTask to %L', currentTask);
+            call defineContext(currentTask, null, custAdminUser, custAdminRole);
             raise notice 'task: % by % as %', currentTask, custAdminUser, custAdminRole;
 
             insert
@@ -53,8 +51,6 @@ create or replace procedure createPackageTestData()
 declare
     cust customer;
 begin
-    set hsadminng.currentUser to '';
-
     for cust in (select * from customer)
         loop
             continue when cust.reference >= 90000; -- reserved for functional testing

src/main/resources/db/changelog/138-hs-unixuser-test-data.sql

@@ -13,8 +13,6 @@ declare
     pacAdmin    varchar;
     currentTask varchar;
 begin
-    set hsadminng.currentUser to '';
-
     select p.uuid, p.name, c.prefix as custPrefix
         from package p
         join customer c on p.customeruuid = c.uuid
@@ -26,9 +24,7 @@ begin
             currentTask = 'creating RBAC test unixuser #' || t || ' for package ' || pac.name || ' #' || pac.uuid;
             raise notice 'task: %', currentTask;
             pacAdmin = 'pac-admin-' || pac.name || '@' || pac.custPrefix || '.example.com';
-            execute format('set local hsadminng.currentTask to %L', currentTask);
-            execute format('set local hsadminng.currentUser to %L', pacAdmin);
-            set local hsadminng.assumedRoles = '';
+            call defineContext(currentTask, null, pacAdmin, null);
 
             insert
                 into unixuser (name, packageUuid)
@@ -46,8 +42,6 @@ declare
     pacAdmin    varchar;
     currentTask varchar;
 begin
-    set hsadminng.currentUser to '';
-
     for pac in
         (select p.uuid, p.name
              from package p