experiment: Add tests for RSA-PSS.
* tests/t-rsa-pss.c (one_test_sexp): New.
Preparing data template for RSS-PSS is a bit tricky, because
default is generating salt internally and we need to supply
"(salt-length 1:0)" to specify no salt.
- GnuPG-bug-id: T4894
- Signed-off-by: NIIBE Yutaka <gniibe@fsij.org>