crit-cert.pem:
  Simple self-signed certificate with critical Basic Constraints and Key Usage
  extensions.
dh512.pem, dh512.der:
  512-bit DH parameters. Used for testing the rejection of lower-bit sized DH
  keys.
dh1024.pem, dh1024.der:
  1024-bit DH parameters. Used for testing the rejection of lower-bit sized DH
  keys.
digsigku.pem:
  ECC certificate with a KeyUsage extension without the digitalSignature bit
  set.
