[PL/SQL Base64 encode decode] #oracle

base64.sql

declare
  r raw(32767);
begin
  r := utl_raw.cast_to_raw('Test');
  dbms_output.put_line(r);

  r := utl_encode.base64_encode(r);
  dbms_output.put_line(utl_raw.cast_to_varchar2(r));

  r := utl_encode.base64_decode(r);
  dbms_output.put_line(utl_raw.cast_to_varchar2(r));
end;
/

query.sql

select utl_raw.cast_to_varchar2(utl_encode.base64_encode(utl_raw.cast_to_raw('Aladdin:open sesame')))
  from dual;
  
select utl_raw.cast_to_varchar2(utl_encode.base64_decode(utl_raw.cast_to_raw('QWxhZGRpbjpvcGVuIHNlc2FtZQ==')))
  from dual;