web hosting - Unable to negotiate with XX.XXX.XX.XX: no matching host key type found. Their offer: ssh-dss

Question

I am trying to create a git repository on my web host and clone it on my computer. Here's what I did:

1. I created a repository on the remote server.
2. I generated a key pair: ssh-keygen -t dsa.
3. I added my key to ssh-agent.
4. I copied to the server public key in ~/.ssh.

And then, after an attempt to run the command git clone ssh://user@host/path-to-repository, I get an error:

Unable to negotiate with XX.XXX.XX.XX: no matching host key type found. Their offer: ssh-dss
fatal: Could not read from remote repository.
Please make sure you have the correct access rights and the repository exists.

What does that mean?

Answer 1

The recent openssh version deprecated DSA keys by default. You should suggest to your GIT provider to add some reasonable host key. Relying only on DSA is not a good idea.

As a workaround, you need to tell your ssh client that you want to accept DSA host keys, as described in the official documentation for legacy usage. You have few possibilities, but I recommend to add these lines into your ~/.ssh/config file:

Host your-remote-host
    HostkeyAlgorithms +ssh-dss

Other possibility is to use environment variable GIT_SSH to specify these options:

GIT_SSH_COMMAND="ssh -oHostKeyAlgorithms=+ssh-dss" git clone ssh://user@host/path-to-repository