Archives: Azure SSO from Oracle APEX with group membership
Tim has written an excellent blog post on how to connect your APEX application with Azure SSO. I used this article as a base with my work, with a few modifications.
You can also set Authentication provider to OpenID Connect Provider, then you only have to supply one Azure SSO configuration URL, everything else will be automatically configured. Documentation is here. You can configure like that:
- Authentication provider: OpenID Connect Provider
- Discovery URL: https://login.microsoftonline.com/your_Azure_AD_tenant_UUID_here/v2.0/.well-known/openid-configuration
For Oracle Wallet setup, you can use my solution to automatically convert Linux system trusted certificates to Oracle Wallet format.
Another requirement for me was to make some Azure user group membership available for the APEX application. One option to query this from APEX is to make a post authentication call to Azure GraphQL endpoint /me/memberOf. For this to work, Azure administrator needs to grant your application User.Read privilege at minimum. Then /me/memberOf will list you only the group object ID-s that the logged in user is a member, but no group names nor other information (if you require to see group names, then your application also needs Group.Read.All permission, but for my case it required approvals and more red tape that I really did not want to go through).
The solution below is to create APEX post authentication procedure that will store the Azure enabled roles in APEX user session collection APP_USER_ENABLED_ROLES. Afterwards you can use the collection in APEX application as you see fit, also use it in APEX authorization schemes.
Archives: Convert Linux system CA trust store to Oracle Wallet file
If you need to make HTTPS requests (or other TLS secured network requests) from Oracle database, you also need a wallet containing the certification authority (CA) certificates you trust. In todays distributed web world it is quite painful to keep updated. But operating systems and popular web browsers already come with bundled trust lists – the certificate authorities the OS vendor has considered trustworthy according to their policies. Wouldn’t it be nice to make it usable for Oracle Database?
Enterprise linuxes have package ca-certificates that contain the CA-s Mozilla has deemed trustworthy, this is available in file /etc/pki/ca-trust/extracted/pem/tls-ca-bundle.pem
Oracle Wallet is basically PKCS#12 container, so we can just use standard openssl command to generate it.
I tested it with Oracle Database 19.18 and it accepted the generated file without any problems.
Archives: Curious case of “Application Express is currently unavailable” after downgrade
In order to prepare for APEX 23.1 upgrade in production, I upgraded several test environments from existing 21.1.5 to 23.1.3. Nothing special about the upgrade, no errors. But then developers requested I downgrade one of the environments back to 21.1, since they needed to make some changes to existing apps.
APEX downgrade should be easy, since APEX always installs new version into a new schema (23.1 goes to APEX_230100, 21.1 is installed in APEX_210100) and then it just copies over the application metadata. Downgrade then it should be easy, just point APEX back to the old schema. Downgrade is documented and Oracle does provide apxdwngrd.sql script for it.
After running apxdwngrd.sql and dropping APEX_230100 schema – the users started receiving a page from ORDS that “Application Express is currently unavailable”.
No other information, no other error message in ORDS logs, no errors in alert.log. How does it determine that APEX is unavailable? No idea.
I did the usual checks, I saw ORDS sessions connected to the database, so there were no connection issues.
SQL> select * from dba_registry where comp_id='APEX'; version = 21.1.5 status = VALID procedure = VALIDATE_APEX SQL> exec sys.validate_apex; PL/SQL procedure successfully completed. SQL> select * from dba_registry where comp_id='APEX'; version = 21.1.5 status = VALID
APEX component in the database is valid, with correct version and after validation it is still VALID.
SQL> select count(*) from dba_objects where owner='APEX_210100' and status != 'VALID'; 0
There are no invalid objects in the APEX schema, but I did see some public synonyms still left over from APEX 23.1. And then recreated all APEX 21.1 public synonyms.
SQL> select 'drop public synonym '||synonym_name||';' from dba_synonyms where owner='PUBLIC' and table_owner like 'APEX_230100'; ... cleaned them up SQL> alter session set current_schema = APEX_210100; SQL> exec wwv_flow_upgrade.recreate_public_synonyms('APEX_210100');
No help… Still the same “Application Express is currently unavailable” to the users.
After that I got a useful tip in twitter to check view APEX_RELEASE.
Version is correct, but PATCH_APPLIED=APPLYING? That cannot be right and checking the not yet upgraded source production database it said PATCH_APPLIED=APPLIED.
First I tried to reapply 21.1.5 patch, and then 21.1.7 patch, but none of them reset this PATCH_APPLIED field.
Time to dig into APEX internals. I see that PATCH_APPLIED field is populated using function call wwv_flow_platform.get_patch_status_and_init_cgi but the code for it is wrapped. We also have the good old SQL trace that showed me that this fuction is calling
SELECT VALUE FROM APEX_210100.WWV_FLOW_PLATFORM_PREFS WHERE NAME = 'APEX_PATCH_STATUS';
And there is see value APPLYING as a plain string. What if I just update it?
update APEX_210100.WWV_FLOW_PLATFORM_PREFS set value='APPLIED' WHERE NAME = 'APEX_PATCH_STATUS';
And the “Application Express is currently unavailable” message is gone and APEX works again! My guess is that something in the 23.1 upgrade process sets the old schema to APPLYING mode and then downgrade does not reset it. Sounds like a bug.
NB! Don’t do it in production – talk to Oracle Support first. I only did it because it was development environment and developers wanted to get their environment back fast.
Archives: Authenticating Oracle database users with Radius
I’ve been using the old good Radius authentication protocol to authenticate database accounts (created for humans) with Active Directory credentials. It may sound strange use case, specially since Oracle also advertises its own Active Directory integration (Centrally Managed Users) and also there is Kerberos. I’ve had the following problems with them:
- CMU – in order to use Active Directory passwords, AD schema needs to be modified and AD filter installed on AD side. I think the latter removes this feature from consideration.
- Kerberos – passwordless login is very tempting and if you get it running on Oracle side – definetly a feature to consider. But deploying at scale and maintaining it is a nightmare, almost impossible to automate.
Radius on the other hand – Windows domain controllers have Radius server built in and it is also very easy to deploy at large scale and maintain on Oracle database side.
Configure database server
First add the following to database sqlnet.ora. File /u01/app/oracle/radius.key is a simple text file containing just the Radius secret. 10.0.0.1 and 10.0.0.2 are my Radius servers running on Windows, both using port 1812.
# Radius authentication settings SQLNET.RADIUS_AUTHENTICATION_PORT = 1812 SQLNET.RADIUS_SECRET=/u01/app/oracle/radius.key SQLNET.RADIUS_AUTHENTICATION = 10.0.0.1 SQLNET.RADIUS_ALTERNATE = 10.0.0.2
In the database itself set parameter os_authent_prefix to empty string:
alter system set os_authent_prefix='' scope=spfile;
And create the database users IDENTIFIED EXTERNALLY, and database username must match WInodws AD username.
CREATE USER ilmker IDENTIFIED EXTERNALLY;
Configure the client
The bad thing with Radius authenticated users is that the database client must also support Radius. Oracle thick driver supports it just fine, also JDBC thin driver.
When using Oracle thick client (Instatnt client), turn on Radius authentication by adding it to sqlnet.ora:
$ cat ORACLE_CLIENT_HOME/network/admin/sqlnet.ora SQLNET.AUTHENTICATION_SERVICES=(RADIUS)
After that you can use this client to log into the database using both database authenticated users and Radius authenticated users.
JDBC thin driver is a little bit trickier (tested using 21c JDBC driver)
To use Radius add the following Java VM option – but the problem with that is that you cannot use database authenticated users after turning on this option.
If you want to use it with SQL Developer, add the following to product.conf file
As mentioned earlier this would disable database authenticated accounts, so in case of SQL Developer changing product.conf is not desirable.
Since 19c JDBC thin driver, it is also possible to change Java properties within the connection string using EasyConnect syntax:
One bug that I discovered in JDBC thin driver support for Radius (and Oracle is still working on it) – if you use Radius together with TCPS and database server has also enabled Oracle Native Encryption – you will get the following error from JDBC driver IO Error: Checksum fail
This is rather strange error, since when using TCPS – Oracle Native Encryption should be turned off automatically, but this error comes from Native encryption checksumming. To get around it, have to disable Native Encryption checksumming from the client side – which can also be done from inside the connection string.
Archives: Using Secure Application Roles to implement complex data access rules for users
We have hundreds of developers who need access hundreds of application schemas, deployed to multiple locations. Data is sensitive and there is a requirement that each human access must be done via a personal database account that has access to only allowed application schemas. That has always been a struggle for me how to manage all these access privileges in a nice and easy way. Since many many many different databases are involved, database itself cannot be the source of truth for the access privileges and so far we have just synchronised the access privileges from the source of truth system to all individual databases.
I think there is a better way now – Secure Application Roles.
The idea behind them is very flexible – there is no need to grant the individual roles to database users, the users need to execute a procedure (which will do all necessary validations) and then enable the role(s) for the user session.
Lets first set up a common SECURITY_MANAGER schema, that will contain all our security related code and logging.
create user security_manager no authentication default tablespace users quota 1g on users; grant create table, create procedure to security_manager; create table security_manager.allowed_grants ( db_username varchar2(128) not null, db_role varchar2(128) not null, primary key (db_username,db_role) ) organization index; create table security_manager.role_grant_log ( grant_time timestamp default sys_extract_utc(systimestamp) not null, db_username varchar2(128) not null, granted_role varchar2(128) not null, is_allowed number(1) not null, comments varchar2(1000), client_host varchar2(200), client_ip varchar2(50), unified_audit_session_id varchar2(100) );
Here are two helper programs, since ACTIVATE_ROLE procedure below will need to read and write to tables in SECURITY_MANAGER schema and I do not want to grant access to these tables to users directly.
-- The job of the following procedure is just logging the grant request CREATE OR REPLACE PROCEDURE security_manager.log_role_grant (p_requested_role role_grant_log.granted_role%TYPE , p_is_allowed role_grant_log.is_allowed%TYPE , p_comments role_grant_log.comments%TYPE) ACCESSIBLE BY (activate_role) IS PRAGMA AUTONOMOUS_TRANSACTION; BEGIN INSERT INTO role_grant_log (db_username, granted_role, is_allowed, comments , client_host, client_ip, unified_audit_session_id) VALUES (SYS_CONTEXT('USERENV','SESSION_USER') , p_requested_role, p_is_allowed, SYS_CONTEXT('USERENV','HOST') , SYS_CONTEXT('USERENV','IP_ADDRESS') , SYS_CONTEXT('USERENV','UNIFIED_AUDIT_SESSIONID')); COMMIT; END; / -- The following function just check the master autorisation table if -- user is allowed to activate the role or not CREATE OR REPLACE FUNCTION security_manager.is_role_allowed (p_username allowed_grants.db_username%TYPE , p_requested_role role_grant_log.granted_role%TYPE) RETURN boolean ACCESSIBLE BY (activate_role) IS v_is_role_allowed NUMBER; BEGIN SELECT COUNT(*) INTO v_is_role_allowed FROM allowed_grants WHERE db_username = p_username AND db_role = UPPER(p_requested_role); RETURN v_is_role_allowed = 1; END; /
Now the security code itself. The procedure below just checks from a simple table, if the logged in user is allowed to activate the requested role or not and also logs the request. In real life it can be much more complex – the code could make a REST call to external autorisation system and ofcourse logging should be much more detailed.
NB! The procedure must be declared AUTHID CURRENT_USER – using invokers rights.
CREATE OR REPLACE PROCEDURE security_manager.activate_role (p_requested_role allowed_grants.db_role%TYPE , p_comments role_grant_log.comments%TYPE) AUTHID CURRENT_USER IS v_activated_roles VARCHAR2(4000); BEGIN -- Check if users is allowd to activate the requested role IF NOT is_role_allowed(SYS_CONTEXT('USERENV','SESSION_USER'), p_requested_role) THEN log_role_grant(upper(p_requested_role), 0, p_comments); raise_application_error(-20000, 'You are not allowed to activate the requested role.'); END IF; -- Query all roles that are currently active for the session and append the requested role to that list SELECT listagg(role, ',') WITHIN GROUP (ORDER BY role) INTO v_activated_roles FROM ( SELECT role FROM session_roles UNION SELECT upper(p_requested_role) FROM dual ); -- Activate all roles log_role_grant(upper(p_requested_role), 1, p_comments); DBMS_SESSION.SET_ROLE(v_activated_roles); END; /
Now I create the role itself and grant the role read access to one application table. Here IDENTIFIED USING clause does the magic – it tells Oracle that sec_app_role_test1 role can only be enabled by security_manager.activate_role procedure.
CREATE ROLE sec_app_role_test1 IDENTIFIED USING security_manager.activate_role; GRANT READ ON app1.t1 TO sec_app_role_test1;
And my developer personal account is called ILMKER and this account only needs execute privileges on my security package. In real life you would grant this execute to a common role that all developers have (in my case that custom role is called PERSONAL_ACCOUNT).
GRANT execute ON security_manager.activate_role TO ilmker;
By default ILMKER user cannot access table APP1.T1.
ILMKER SQL> SELECT * FROM session_roles; ROLE ----------------- PERSONAL_ACCOUNT ILMKER SQL> SELECT * FROM app1.t1; SQL Error: ORA-00942: table or view does not exist
Lets test using my developer account ILMKER… first I try to request a role that I do not have been granted access to. No luck, I get the exception “ORA-20000: You are not allowed to activate the requested role.”
SQL> SELECT * FROM session_roles; ROLE -------------------- PERSONAL_ACCOUNT SQL> exec security_manager.activate_role('sec_app_role_test1', 'Jira ref: ABC-490'); ORA-20000: You are not allowed to activate the requested role. SQL> SELECT * FROM session_roles; ROLE -------------------- PERSONAL_ACCOUNT SQL> SELECT * FROM app1.t1; SQL Error: ORA-00942: table or view does not exist
After security administrator grants me the role – inserts a row to security_manager.allowed_grants table for this example and NOT executing Oracle GRANT command.
insert into security_manager.allowed_grants (db_username, db_role) values ('ILMKER', upper('sec_app_role_test1')); commit;
I ask my developer to run again.
SQL> SELECT * FROM session_roles; ROLE -------------------- PERSONAL_ACCOUNT SQL> exec security_manager.activate_role('sec_app_role_test1', 'Jira ref: ABC-490'); PL/SQL procedure successfully completed. SQL> SELECT * FROM session_roles; ROLE -------------------- PERSONAL_ACCOUNT SEC_APP_ROLE_TEST1 SQL> SELECT * FROM app1.t1; no rows selected
The developer is happy now! Role was activated in the developer session and developer was able to read the application table. All requests were also logged by SECURITY_MANAGER schema.
SQL> select * from security_manager.role_grant_log; GRANT_TIME DB_USERNAME GRANTED_ROLE CLIENT_HOST CLIENT_IP UNIFIED_AUDIT_SESSION_ID IS_ALLOWED COMMENTS 2023-05-12 15:05:28,478732000 ILMKER SEC_APP_ROLE_TEST1 STH-FVFFV04QQ05R 10.88.17.241 3428220339 0 Jira ref: ABC-490 2023-05-12 15:10:41,923908000 ILMKER SEC_APP_ROLE_TEST1 STH-FVFFV04QQ05R 10.88.17.241 3428220339 1 Jira ref: ABC-490
I think this is a powerful feature to control access to data based on much more complex criteria than just DBA executing GRANT commands. Before enabling the role code can make a REST query to external autorisation system, check the client host IP, check the client authentication method, enable detailed unified auditing policies. Possibilities are endless!