/*
* openssh uses base64 and special formatting for public keys like with "authorized_keys"
* https://man.openbsd.org/ssh-keygen
*/
public static StringBuilder ExportPubKeyBase64(tbl_User user, ICollection <tbl_PublicKey> keys)
{
var callPath = $"{MethodBase.GetCurrentMethod().DeclaringType.Name}.{MethodBase.GetCurrentMethod().Name}";
var sb = new StringBuilder();
foreach (var key in keys)
{
var pubBytes = Encoding.ASCII.GetBytes(key.KeyValue);
var pubKeyInfo = new PublicKeyInfo();
pubKeyInfo.Load(new MemoryStream(pubBytes));
var pubStream = new MemoryStream();
var pubKey = new SshPublicKey(pubKeyInfo);
pubKey.SavePublicKey(pubStream, SshPublicKeyFormat.Pkcs8);
var algo = string.Empty;
switch (pubKey.KeyAlgorithm)
{
case SshHostKeyAlgorithm.DSS:
algo = "ssh-dsa";
break;
case SshHostKeyAlgorithm.RSA:
algo = "ssh-rsa";
break;
//case SshHostKeyAlgorithm.ECDsaNistP256:
// algo = "ecdsa-sha2-nistp256";
// break;
//case SshHostKeyAlgorithm.ECDsaNistP384:
// algo = "ecdsa-sha2-nistp384";
// break;
//case SshHostKeyAlgorithm.ECDsaNistP521:
// algo = "ecdsa-sha2-nistp521";
// break;
//case SshHostKeyAlgorithm.ED25519:
// algo = "ssh-ed25519";
// break;
default:
{
Log.Warning($"'{callPath}' '{user.IdentityAlias}' algorithm {pubKey.KeyAlgorithm} not supported");
continue;
}
}
sb.AppendLine($"{algo} {Convert.ToBase64String(pubKey.GetPublicKey())} {key.Comment}");
}
return(sb);
}
