/usr/lib/jvm-exports/java-1.5.0-gcj-5-amd64/jaas-1.5.0.0.jar is in gcj-5-jdk 5.3.1-14ubuntu2.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/jvm-exports/java-1.5.0-gcj-5-amd64/../../jvm/java-1.5.0-gcj-5-amd64/jre/lib/rt.jar