[SOLVED] Unable to negotiate with XX.XXX.XX.XX: no matching host key type found. Their offer: ssh-dss

Issue

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?

Solution

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

Answered By - Jakuje