Set Oracle wallet for all APEX REST requests

TLDR: I'm trying to setup a Rest Enabled SQL Service (RESS) Reference between two internal servers with self-signed certificates

I have two internal servers as follows:

1. serverA, running Oracle, APEX 20.2 and ORDS 20.3
   • We've created a self-signed certificate we've used as a CA, serverCA.crt
   • We've used serverCA.crt to issue another certificate, server.crt, which we've used to implement SSL on ORDS. This allows us to use https://serverA.com/ords...., which works. albeit with the usual browser warning.

• We've enabled REST and RESS, which has been confirmed by using curl to call the RESS endpoint

2. serverB, running Oracle, APEX 23.2 and ORDS 23.4.
   • I've used orapki to create a wallet, and added serverCA.crt
   • In APEX, I've created a credential, ress_creds, which I will use to create the RESS reference

In SQL Workshop, on serverB, I've successfully run the following block, confirming that my wallet and credentials work, by alternately commenting each out.

declare
    lclob clob;
BEGIN
    apex_web_service.set_request_headers(
            p_name_01   => 'Content-Type', 
            p_value_01  => 'application/sql' );

lclob :=
APEX_WEB_SERVICE.MAKE_REST_REQUEST (
    p_url               => 'https://serverA.com/ords/myschema/_/sql',
    p_http_method       => 'POST'
    ,p_body   => 'select * from emp'
  ,p_wallet_path => 'file:///home/oracle/ords/https_wallet' 
  ,p_credential_static_id => 'ress_creds'
);
dbms_output.put_line(lclob);
end;

Now, on serverB, I've created a Rest Enabled SQL reference with endpoint https://serverA.com/ords/myschema and the 'ress_creds' credential. However, when I click the test button, it fails with:

ORA-29024: Certificate validation failure

It seems that serverB does not know how to find the wallet I created, when performing REST requests, without it being specified. I've tried running

exec utl_http.set_wallet('file:/home/oracle/ords/https_wallet', null);

but that doesn't seem to work. (The wallet was created with auto_login, so the password isn't needed here, but I tried that variation anyway, in vain.)

Is there a way to set the wallet for ALL REST requests initiated by serverB? If not, how can I resolve this?

The wallet for REST Enabled SQL as well as for REST Data Sources is configured in the INTERNAL workspace. After logging in, navigate to Manage Instance, Instance Settings and then to the Wallet section. There you can configure the wallet path (don't forget the file:// prefix) and (optionally) the wallet password. As an alternative, you can (as a DBA User), use the APEX_INSTANCE_ADMIN.SET_PARAMETER procedure.

begin
    apex_instance_admin.set_parameter( 'WALLET_PATH', 'file:///home/oracle/ords/https_wallet');
    commit;
end;