Problems importing an SSH key

[kasoshadow]

I created an SSH key pair some time ago. I want to import it, however, I always get only different error messages: "Unsupported Algorithmen" "Invalid public Key"
To create the key file I had used kittygen (Kitty is a fork of Putty) with ED25519: https://drive.google.com/drive/folde...ThaTE92RmlodkE

Currently I have only two files: a ppk file and an SSH2 public-key file.

Now I go inside of FlashFXP to Sites -> Key-manager -> Import -> RSA / DSA / ECDSA key for SFTP. There I use the pkk as private-key file and give the appropriate password. The SSH2-public-key turn as a public key. When I try to import, the error message "Invalid Public Key" is output. If I leave the public-key field blank, the error message "Unsupported Algorithm" is output.
However, in FlashFXP Help file, "OpenSSH SSH-2" and "PuTTY SSH2" are listed as supported. However, I have neither a * .cer file nor a * .key file. I tried with kittygen and various export formats to import public-key and private-key, but this did not help.

Below is the schema of the two files.

---- BEGIN SSH2 PUBLIC KEY ----
Comment: "ed25519-key-20161216"
AAAAC3Nza****w6lk6h
ghoy
---- END SSH2 PUBLIC KEY ----

PuTTY-User-Key-File-2: ssh-ed25519
Encryption: aes256-cbc
Comment: ed25519-key-20161216
Public-Lines: 2
AAAAC3Nza****w6lk6h
ghoy
Private-Lines: 1
EfPOkHREfK***GfKxyGv/QLm4+z
Private-MAC: ea8c38dec***f08554abdf1

I would be very grateful if you could help me.

[bigstar]

The library we use SecureBlackBox currently doesn't support PuTTY keys with ed25519.

Due to the way SSH keys are managed by SecureBlackBox it would be quite complicated for us to add support without modifying the library directly and we have not found an easy way to do this without introducing many breaking changes.

As soon as they add support we'll be able to import this format.

[kasoshadow]

OK. I'll probably then set up a second SSH key.