test.crt: self signed certificated
    % gpgsm --gen-key # needs gpgsm 2.1

key+cert.pem: cert + unencryped private
    % gpsm --import test.crt
    % gpgsm --export-private-key-p12 -out foo.p12  (no passphrase)
    % openssl pkcs12 -in ns.p12 -clcerts -nodes > key+cert.pem
