/usr/lib/jvm/java-1.5.0-gcj-4.8-amd64/bin/keytool is in gcj-4.8-jre-headless 4.8.4-2ubuntu1~14.04.4.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/jvm/java-1.5.0-gcj-4.8-amd64/bin/../../../../bin/gkeytool-4.8