SSH login using Pageant

[Kimmo]

Hi,

I'm not able to use Pageant with .ppk-file for SSH login. I've included the Pageant 'IdentityAgent- in the ' C:/Users/username/.ssh/config'. Pageant works fine with Windows OpenSSH. 

I use the option "sshKeyFile=C:/Users/username/.ssh/private_key.ppk" with TurboVNC viewer version 3.1.2 but I get an error: "Could not create SSH tunnel: Could not use SSH private key C:\Users\username\.ssh\private_key.ppk: invalid privatekey: [something" with 'something' being some hash. 

Great software nevertheless.

[DRC]

The SSHKeyFile parameter accepts an SSH key in OpenSSH format. It is roughly the equivalent of the -i option in OpenSSH. In other words, it is a command-line override that allows you to promote an SSH key to the top of the chain. It isn’t necessary when using an SSH agent. You should be able to simply add the .ppk file to Pageant, and the TurboVNC Viewer will use the key through Pageant automatically. No further TurboVNC parameters or OpenSSH config file directives are necessary.

On Sep 19, 2024, at 5:05 AM, Kimmo <kimmo.h...@gmail.com> wrote:



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[Kimmo]

I've loaded the .ppk file to Pageant and the SSH connection works with Putty and Windows OpenSSH but I get the password inquiry in TurboVNC (without any TurboVNC parameters).

[DRC]

OK, that sounds like a bug, then. Which version of Pageant are you using? How did you generate the key? (I ask the latter question because there are still some key algorithms that the TurboVNC Viewer’s built-in SSH client doesn’t support— specifically Ed25519. I intend to address that in TurboVNC 3.2.)

On Sep 20, 2024, at 5:07 AM, Kimmo <kimmo.h...@gmail.com> wrote:

I've loaded the .ppk file to Pageant and the SSH connection works with Putty and Windows OpenSSH but I get the password inquiry in TurboVNC (without any TurboVNC parameters).

To view this discussion on the web visit https://groups.google.com/d/msgid/turbovnc-users/4de5ed19-76f8-4042-98e4-aa8390b96132n%40googlegroups.com.

[Kimmo]

Hi. Pageant version is 0.81 and I generated the key using ssh-keygen (Windows 11 WSL2 - Ubuntu 22.04 - openssh-client 1:8.9p1-3ubuntu0.10). The key type is actually Ed25519. I will change the key type or wait for the TurboVNC 3.2. Thanks for the detailed reply.

[DRC]

I reproduced the issue, and it is definitely due to the use of an Ed25519 key.  I guess ssh-agent communicates the key in such a way that the key type doesn't matter, but it does matter with Pageant.  Ed25519 support is a high priority for TurboVNC 3.2.

DRC

To view this discussion on the web visit https://groups.google.com/d/msgid/turbovnc-users/fab713cc-b53b-4cdd-ba6a-dfebf4facad9n%40googlegroups.com.

[DRC]

Ignore my previous remark.  I forgot that, if you want to use Ed25519 keys via ssh-agent or Pageant with the current version of TurboVNC, you have to add

    PubKeyAcceptedAlgorithms +ssh-ed25519

to ~/.ssh/config (%USERPROFILE%\.ssh\config on Windows.)

That is because the SSH client doesn't explicitly support the signature scheme, so you have to tell it that it is OK to use that scheme (which it is, because the SSH agent supports it.)

I am still working on explicit Ed25519 support, which will make it unnecessary to modify the OpenSSH config file.

DRC

[DRC]

Ed25519 support has just been pushed to the dev branch as well, so the latest 3.2 Evolving builds now have it (https://turbovnc.org/DeveloperInfo/PreReleases).  I haven't thoroughly tested the feature yet, so let me know if you run into any problems.

DRC

[Kimmo]

Great. Thanks. Will let you know if I run into any problems.