//
  // Valid values are:
  //  "signing", "digital signature", "content commitment",
  //  "key encipherment", "key agreement", "data encipherment",
  //  "cert sign", "crl sign", "encipher only", "decipher only", "any",
  //  "server auth", "client auth",
  //  "code signing", "email protection", "s/mime",
  //  "ipsec end system", "ipsec tunnel", "ipsec user",