Renci.SshNet.Common.SshAuthenticationException: Permission denied (publickey)

[gmlion]

I'm trying to connect to an Ubuntu server with my private key, but I can't get it working

let execution () =
    let connectionInfo = new ConnectionInfo(host, "root", new PrivateKeyAuthenticationMethod("./resources/keys/id_rsa"))
    use client = new SshClient(connectionInfo)
    do client.Connect()
    ()
    
do execution ()

The code is a F# script but I guess it's readable.
I tested the file to be reachable (looks like the exception if the path is wrong is the same) and I also tried using the key with ssh cli, succesfully. So the key should be good.

EDIT: the same error occurs using both the NuGet package and the current develop branch on GitHub
EDIT 2: i managed to get it working. This is the working code:

let execution () =
    let connectionInfo = new ConnectionInfo(host, "root", new PrivateKeyAuthenticationMethod("root", new PrivateKeyFile("./resources/keys/id_rsa")))
    use client = new SshClient(connectionInfo)
    do client.Connect()
    ()
    
do execution ()

I see it's a bit redundant (having to specify twice the username). Is there a better way, similar to the multi-factor example?

[hovek]

Windows C#, .NET 4.5. I get permission denied just out of the blue, it worked fine and suddenly throws permission denied for every file, FileZilla works fine.

[kranz912]

I got the same issue. It was working on my development machine running windows 10. When I deployed it to our production environment I get this message. Both are pointing to the same private key file.

[drieseng]

@gmlion: in the first code snippet you actually specified "./resources/keys/id_rsa" as user name, hence the authentication failure.

I agree that it's a bit weird to specify the user name twice. Please submit a separate issue for this.

[drieseng]

@hovek, @kranz912: If you have more information (eg. server logs), please submit a separate issue.

@kranz912: Were you actually accessing the same SSH server on both your development machine and your production environment?

[gmlion]

@drieseng The single argument PrivateKeyAuthenticationMethod constructor is used in the multi-factor-authentication example in the README, I suppose it no longer works that way?

[hotyes]

hi @gmlion , have you solved this problem ? thanks

[igavva]

A simple solution.

Add this line in /etc/ssh/sshd_config.

PubkeyAcceptedAlgorithms +ssh-rsa
Afterwards, restart the sshd service to make the new settings come into effect.

$ sudo systemctl restart sshd

[WojciechNagorski]

Fixed by #1177 and #1180

[WojciechNagorski]

Version 2023.0.0 has been published https://www.nuget.org/packages/SSH.NET/2023.0.0