SFTP keys

Hi,

I'm currently in the trial period for DOpus, using 2.27, but I was having the same issues with public key / private key auth via SFTP that were happening on previous versions.

If I try to load the host's provided OpenSSH SSH-2 key directly, I get the expected error:

Unable to use this key file (OpenSSH SSH-2 private key (new format))

If I use the current version of puttygen.exe to load this key file and save it as a .ppk in the host's required DSA format, then DOpus throws these errors in the console:

Unable to load key (PuTTY key format too new)
...
Disconnected: No supported authentication methods available (server sent: publickey)

This occurs whether the private key file has a key passphrase assigned or not.

Using the old version of puttygen.exe linked in Leo's post from Jul 26, 2021 to generate the local private key in .ppk format does however work, even with a passphrase assigned to the key.

While I'm grateful to have a working solution, it's not ideal to have to keep an old version of puttygen around just for DOpus. May I please ask if you're planning to support the new format of ppk key file in the future?

Thanks for reporting that. We'll look into it. I'm surprised that the new puttygen format isn't working after the updates in 12.27.

In Puttygen, select the Parameters for saving key files command from the Key menu:

And change the key version to 2:

I have retested this with new Putty version, it now works with Putty as well, what am I supposed to do to get it working with Dopus 13? I still see only a place to configure one file in settings... Is this still unsupported?

Which error are you seeing? There have been a couple of different issues discussed in this thread.

Reading key file "C:\Test.ppk"
Unable to load key (PuTTY key format too new)
Unable to load key file "C:\Test.ppk" (PuTTY key format too new)
Using username "root".
Disconnected: No supported authentication methods available (server sent: publickey)
SSH: Fatal: Disconnected: No supported authentication methods available (server sent: publickey)
Connection closed

However only one file is able to be selected, unless I'm missing something...

The key needs to be saved out in V2 format, as Jon showed above.

Load it into PuttyGen, set the format to V2, then save it back out again.

You only need to select one file: the V2 version of the key.

Saving a V2 version of it doesn't break the V3 version; you can use them both in different software (or can probably use the V2 key in everything if you want only one file).

Using v2 format:

Reading key file "C:\Test.ppk"
Using username "root".
Offered public key
Server refused our key
Server refused our key
Disconnected: No supported authentication methods available (server sent: publickey)
SSH: Fatal: Disconnected: No supported authentication methods available (server sent: publickey)
Connection closed