enum KeyExchange {
  ftpKeyExchangeUnknown = 0,
  ftpKeyExchangeDiffieHellmanGroup1SHA1 = 1,
  ftpKeyExchangeDiffieHellmanGroup14SHA1 = 2,
  ftpKeyExchangeDiffieHellmanGroupExchangeSHA1 = 3,
  ftpKeyExchangeDiffieHellmanGroupExchangeSHA256 = 4,
  ftpKeyExchangeRSA1024SHA1 = 5,
  ftpKeyExchangeRSA2048SHA256 = 6,
  ftpKeyExchangeECDH256 = 7,
  ftpKeyExchangeECDH384 = 8,
  ftpKeyExchangeECDH521 = 9
};