Linking my VPS to a Virtual Desktop. Authentication Error

July 26, 2017 109 views
Getting Started Ubuntu 16.04

So I'm really struggling with linking my virtual private server to a virtual desktop. I want to add my custom bot to the virtual desktop to work on it in there.

What I've done so far:

  1. droplet made through DigitalOcean with a Ubuntu 16.04 setup

  2. created public and private keys through PuTTyGen

  3. went through initial server setup:

  4. connected my public key to my droplet. Cut key from puttygen and pasted into authorized_keys

  5. Installed TightVNC and followed the configuration instructions:

Regardless, when I try to login from my windows terminal with the user I created that has full admin/sudo access (even tried making my windows terminal linux-friendly through developer mode), I STILL get this error:
--Putty error: No supported authentication methods available (server sent: publickey) --

I followed multiple fixes from various forums, but still no luck. So frustrating....Please help?

1 Answer


Unless you're using PuTTy to log in to the Droplet, a private key generated by PuTTy won't work with a standard shell log in -- those keys are specific to PuTTy and would need to be used by PuTTy only.

If you're using something such as:

ssh user@ip -i /path/to/private.key

I would recommend generating a second key pair on the Droplet itself and storing the private key to your local environment and placing the public key in your authorized_keys file.

You can generate a standard OpenSSH key by using ssh-keygen.


ssh-keygen -a 500 \
           -b 4096 \
           -C "" \
           -E sha256 \
           -o \
           -q \
           -t rsa

ed25519 Key

ssh-keygen -a 500 \
           -C "" \
           -E sha256 \
           -o \
           -q \
           -t ed25519

PuTTy works a little differently than your standard Terminal emulator (such as Terminal on MacOS or even most linux distros). They keys it uses are only usable by PuTTy, FileZilla, and a few other select software applications.

While PuTTy will generate an OpenSSH Key, it's often easier to generate one on the Droplet and then use it instead so you don't have to worry about the differences between the two.

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