Enterprise Server 3.15 is currently available as a release candidate.

Error: Permission denied (publickey)

A "Permission denied" error means that the server rejected your connection. There could be several reasons why, and the most common examples are explained below.

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Should the sudo command or elevated privileges be used with Git?

You should not be using the sudo command or elevated privileges, such as administrator permissions, with Git.

If you have a very good reason you must use sudo, then ensure you are using it with every command. If you generate SSH keys without sudo and then try to use a command like sudo git push, you won't be using the same keys that you generated.

Check that you are connecting to the correct server

To make sure you are connecting to the right domain, you can enter the following command:

Shell
ssh -vT git@HOSTNAME

You should see this output:

> OpenSSH_8.1p1, LibreSSL 2.7.3
> debug1: Reading configuration data /Users/YOU/.ssh/config
> debug1: Reading configuration data /etc/ssh/ssh_config
> debug1: /etc/ssh/ssh_config line 47: Applying options for *
> debug1: Connecting to HOSTNAME port 22.

The connection should be made on port 22.

Always use the "git" user

All connections, including those for remote URLs, must be made as the "git" user. If you try to connect with your GitHub Enterprise Server username, it will fail:

$ ssh -T GITHUB-USERNAME@HOSTNAME
> Permission denied (publickey).

If your connection failed and you're using a remote URL with your GitHub Enterprise Server username, you can change the remote URL to use the "git" user.

You should verify your connection by typing:

Shell
ssh -T git@HOSTNAME

You should see this output:

> Hi USERNAME! You've successfully authenticated...

Make sure you have a key that is being used

  1. Open TerminalTerminalGit Bash.

  2. Verify that you have a private key generated and loaded into SSH.

    # start the ssh-agent in the background
$ eval "$(ssh-agent -s)"
> Agent pid 59566
$ ssh-add -l -E sha256
> 2048 SHA256:274ffWxgaxq/tSINAykStUL7XWyRNcRTlcST1Ei7gBQ /Users/USERNAME/.ssh/id_rsa (RSA)

If you have GitHub Desktop installed, you can use it to clone repositories and not deal with SSH keys.

  1. If you are using Git Bash, turn on ssh-agent:

    # start the ssh-agent in the background
$ eval "$(ssh-agent -s)"
> Agent pid 59566

    If you are using another terminal prompt, such as Git for Windows, turn on ssh-agent:

    # start the ssh-agent in the background
$ eval $(ssh-agent -s)
> Agent pid 59566

    Note

    The eval commands above start ssh-agent manually in your environment. These commands may fail if ssh-agent already runs as a background system service. If that happens, we recommend you check the relevant documentation for your environment.

  2. Verify that you have a private key generated and loaded into SSH.

    $ ssh-add -l -E sha256
> 2048 SHA256:274ffWxgaxq/tSINAykStUL7XWyRNcRTlcST1Ei7gBQ /Users/USERNAME/.ssh/id_rsa (RSA)

  1. Open TerminalTerminalGit Bash.

  2. Verify that you have a private key generated and loaded into SSH.

    $ ssh-add -l -E sha256
> 2048 SHA256:274ffWxgaxq/tSINAykStUL7XWyRNcRTlcST1Ei7gBQ /Users/USERNAME/.ssh/id_rsa (RSA)

The ssh-add command should print out a long string of numbers and letters. If it does not print anything, you will need to generate a new SSH key and associate it with GitHub Enterprise Server.

Tip

On most systems the default private keys (~/.ssh/id_rsa and ~/.ssh/identity) are automatically added to the SSH authentication agent. You shouldn't need to run ssh-add path/to/key unless you override the file name when you generate a key.

Getting more details

You can also check that the key is being used by trying to connect to git@HOSTNAME:

Shell
ssh -vT git@HOSTNAME

You'll see output like this:

> ...
> debug1: identity file /Users/YOU/.ssh/id_rsa type -1
> debug1: identity file /Users/YOU/.ssh/id_rsa-cert type -1
> debug1: identity file /Users/YOU/.ssh/id_dsa type -1
> debug1: identity file /Users/YOU/.ssh/id_dsa-cert type -1
> ...
> debug1: Authentications that can continue: publickey
> debug1: Next authentication method: publickey
> debug1: Trying private key: /Users/YOU/.ssh/id_rsa
> debug1: Trying private key: /Users/YOU/.ssh/id_dsa
> debug1: No more authentication methods to try.
> Permission denied (publickey).

In this example, SSH did not find any keys.

  • "-1" at the end of the "identity file" lines means SSH couldn't find a file to use.
  • "Trying private key" lines indicate that no file was found.

If a file existed, those lines would be "1" and "Offering public key", as in this output:

> ...
> debug1: identity file /Users/YOU/.ssh/id_rsa type 1
> ...
> debug1: Authentications that can continue: publickey
> debug1: Next authentication method: publickey
> debug1: Offering RSA public key: /Users/YOU/.ssh/id_rsa

Verify the public key is attached to your account

You must provide your public key to GitHub Enterprise Server to establish a secure connection.

  1. Open Terminal.

  2. Start SSH agent in the background.

    $ eval "$(ssh-agent -s)"
> Agent pid 59566

  3. Find and take a note of your public key fingerprint.

    $ ssh-add -l -E sha256
> 2048 SHA256:274ffWxgaxq/tSINAykStUL7XWyRNcRTlcST1Ei7gBQ /Users/USERNAME/.ssh/id_rsa (RSA)

  4. In the upper-right corner of any page on GitHub, click your profile photo, then click Settings.

  5. In the "Access" section of the sidebar, click SSH and GPG keys.

  6. Compare the list of SSH keys with the output from the ssh-add command.

  1. Open the command line.

  2. Start SSH agent in the background.

    $ ssh-agent -s
> Agent pid 59566

  3. Find and take a note of your public key fingerprint.

    $ ssh-add -l -E sha256
> 2048 SHA256:274ffWxgaxq/tSINAykStUL7XWyRNcRTlcST1Ei7gBQ /Users/USERNAME/.ssh/id_rsa (RSA)

  4. In the upper-right corner of any page on GitHub, click your profile photo, then click Settings.

  5. In the "Access" section of the sidebar, click SSH and GPG keys.

  6. Compare the list of SSH keys with the output from the ssh-add command.

  1. Open Terminal.

  2. Start SSH agent in the background.

    $ eval "$(ssh-agent -s)"
> Agent pid 59566

  3. Find and take a note of your public key fingerprint. If you're using OpenSSH 6.7 or older:

    $ ssh-add -l
> 2048 a0:dd:42:3c:5a:9d:e4:2a:21:52:4e:78:07:6e:c8:4d /Users/USERNAME/.ssh/id_rsa (RSA)

    If you're using OpenSSH 6.8 or newer:

    $ ssh-add -l -E md5
> 2048 MD5:a0:dd:42:3c:5a:9d:e4:2a:21:52:4e:78:07:6e:c8:4d /Users/USERNAME/.ssh/id_rsa (RSA)

  4. In the upper-right corner of any page on GitHub, click your profile photo, then click Settings.

  5. In the "Access" section of the sidebar, click SSH and GPG keys.

  6. Compare the list of SSH keys with the output from the ssh-add command.

If you don't see your public key in GitHub Enterprise Server, you'll need to add your SSH key to GitHub Enterprise Server to associate it with your computer.

Warning

If you see an SSH key you're not familiar with on GitHub Enterprise Server, delete it immediately and contact your site administrator for further help. An unidentified public key may indicate a possible security concern. For more information, see "Reviewing your SSH keys."