Url and DAD authentication

Question

apex v2.2
Scenario is
Apex users are authenticated using database authentication.
Once authenticated the users may press a column link to a
non apex DAD stored procedure call which then ask for autentication.
sample call is - which executes a report request and pass back a pdf to the browser
http://host:port/<dad>/<package.procedure>?param1=1
Within the apex security model can I somehow bypass the user/pw challenge as the user signed in has permission to execute the call and a public user shouldn't have access
This is the appex DAD
<Location /pls/apex>
SetHandler pls_handler
Order deny,allow
Allow from all
AllowOverride None
PlsqlDatabaseUsername APEX_PUBLIC_USER
PlsqlDatabasePassword xxxxxxxx
PlsqlDatabaseConnectString train:1521:training SIDformat
PlsqlDefaultPage apex
PlsqlDocumentTablename wwv_flow_file_objects$
PlsqlDocumentPath docs
PlsqlDocumentProcedure wwv_flow_file_mgr.process_download
PlsqlAuthenticationMode Basic
PlsqlNLSLanguage AMERICAN_AMERICA.AL32UTF8
</Location>
Any ideas ?
Thanks
Pete

Answer 1

Still no joy!
Currently there's a region with some items and a button
when submitting the button GO, page process GO executes:
htp.init;
apex_application.g_page_text_generated := true;
owa_util.mime_header ('application/x-sql',false);
htp.p('Content-Disposition: attachment; filename=xxxxxxxxxxxx');
owa_util.mime_header('application/pdf', false);
owa_util.http_header_close;
htp.p('Content-Disposition: attachment; filename=test.pdf');
<package>.download_doc(517); -- see below
"some processing takes place" but the document is not being displayed
I've tried the different mime_header and Content-Disposition setttings
Do I need to redirect the content sent from the server somewhere else?
Calling the procedure via mod pl/sql works
Thanks for your reply.
Pete
===
procedure download_doc(p_file_id upload_reports.ur_id%type
,p_mime_type varchar2 default 'application/pdf')
as
l_lob upload_reports.report_blob%type;
l_mime varchar2(30);
begin
select f.report_blob
into l_lob
from upload_reports f
where f.ur_id = p_file_id;
owa_util.mime_header('application/pdf', false);
owa_util.http_header_close;
wpg_docload.download_file(l_lob);
end;