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AndFTP cannot negotiate key type

Posted: Mon Nov 07, 2022 5:48 pm
by amganq

I am an Android 12 user and running AndFTP which is a great tool to connect to (almost) any Linux Box. I love it ! However, I ran into a problem with it...

I have a trouble running AndFTP v6.3 on Android 12 connecting to my Linux Server at Home.

I've recently upgraded my Linux Server to Ubuntu 22.04.1 (OpenSSH_8.9p1 Ubuntu-3, OpenSSL 3.0.2) and AndFTP does not connect anymore using the PubKey method.

auth.log on the server throws the following:

Code: Select all

sshd[249451]: userauth_pubkey: key type ssh-rsa not in PubkeyAcceptedAlgorithms [preauth]
My SSH Key is OK (it spits out a SHA256 fingerprint), also I use this key with JuiceSSH (on Android 12) and I use this key on my laptop so the Key is OK.
All of the above use another more sophisticated mechanism, not just plain "ssh-rsa".
The only one that seems to have a trouble authenticating is AndFTP.

From what I understand, OpenSSH has put some security restrictions in place in order not to allow weak algorithms to be used.

I assume AndFTP needs a key upgrade procedure or something like that...

If anyone can help, please... otherwise, I must change AndFTP to other SFTP Client.

Re: AndFTP cannot negotiate key type

Posted: Wed Nov 09, 2022 8:03 am
by support

In your AndFTP configuration, Advanced tab => Expert settings, there is a SSH provider option, could you try all (one by one, don't forget to click save each time) with your key?