/usr/share/java/signpost-commonshttp4-1.2.1.2.jar is in liboauth-signpost-java 1.2.1.2-1.5.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/java/signpost-commonshttp4.jar
/usr/share/java/signpost-commonshttp4.jar