Common SSH Problems

This page addresses some regularly occurring problems and questions regarding connecting via SSH.

Warning: unprotected key file!

If you get a message like this:

Permissions 0777 for '.ssh/id_rsa' are too open.
It is required that your private key files are NOT accessible by others.
This private key will be ignored. Permission denied (publickey,gssapi-keyex,gssapi-with-mic,hostbased).

This indicates that the file permissions og your private key file are too open. It has nothing to do with the password set on the SSH-key itself. The solution is to make the key only readable to your own user with: chmod 600 <path/to/your-key>

You can verify it by either trying to log in again, or use ls -l <path/to/your-key>:

ls -l ~/.ssh/id_rsa
-rw------- 1 marcus marcus 1766 Jun 13  2018 /home/marcus/.ssh/id_rsa

The -rw——- shows that the file is only read- and writable for my users. If you are not familiar with file permissions, you can find information on that in our Introductory course or online.


If you tried changing the file permissions and you still cannot connect, please veryfy with ls -l <path/to/your-key> that your file permissions are correct. If you use WSL and you are working with Windows data (i.e. your working directory is somewhere in the Windows-Filesystem, not the WSL file system), it may not be possible to change the permission. In that case, please copy the key to the WSL file system with:

mkdir -p ~/.ssh/
cp <path/to/your-key> ~/.ssh/
chmod 600 ~/.ssh/<your-key>
ls -l ~/.ssh/<your-key>

The last command is to verify the permissions of the key. If all that still doesn't work, feel free to reach out to us.

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