/usr/lib/libpkcs11_sw.so.0 is in libopencryptoki0 2.3.1+dfsg-3.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/opencryptoki/stdll/libpkcs11_sw.so.0
/usr/lib/opencryptoki/stdll/libpkcs11_sw.so.0