Why doesn't my SSH key work for connecting to github?

Question

Note: I\'m not a newb, and I\'ve done this a gazillion times, but for some reason today it decided not to work.

I keep getting the Permission denied (publickey).

Answer 1

The GitHub ssh setup mentions testing your GitHub connection with:

$ ssh -T git@github.com

That follow the ssh uri syntax (also illustrated in "this answer").

But you did:

ssh github.com

(without any user). In that case, ssh reverts to the SCP syntax, which relies on a ~/.ssh/config file, with a section "github.com", to list:

• the user
• the hostname
• (and optionally the public key location, but by default it will try ~/.ssh/id_rsa.pub)

To change it to a regular SSH URL, don't edit directly your .git/config file, as shown below.
Use the command git remote set-url:

git remote set-url origin git@github.com:username/repo.git

Answer 2

I had a similar problem, github did not use my SSH key. I always had to enter my username and password.

I've been looking at .git/config, under [remote "origin"] there was:

    url = http://github.com/path/to/repository

or

    url = https://github.com/path/to/repository

I changed the line into

    url = ssh://git@github.com/path/to/repository

and then it worked.

Answer 3

GitHub recently underwent an audit of ALL keys. Go to the key section of your account to re-approve it.

Answer 4

If it works for other repositories, but not one in particular, then you are probably using the wrong remote url(i.e. https instead of git@github.com)

1. First, double check that your git ssh connection is working:

   ssh -T git@github.com
   

2. If it works, check your remote:

   git remote -v
   

   it will display something like this:

   origin  https://github.com/username/repo(fetch)
   origin  https://github.com/username/repo(push)
   

3. If the remotes indicate https at the beginning, then you need to change this url with:

   git remote set-url origin git@github.com:usertname/repo.git
   

Go here for more details.

Answer 5

I had a similar issue when moving from Windows 7 to Windows 10 using Git for Windows.

I had my SSH keys for a Gitlab of our company running on my old computer and using this ssh command in the Windows cmd or the Git Bash worked fine (with git.my_server.com replaced by the Git server domain) - so my Windows was able to use the key, but Git for Windows was not:

ssh -T git@git.my_server.com

(which displayed: "Welcome to GitLab, @my_username!). However, when trying to clone, push or pull with git, I got the "Permission denied (publickey)" error message.

I initially couldn't find the location/environment of the SSH keys that Git uses, so I tried to copy/paste the ssh keys into this environment by using the Git Bash:

1. Open the Git Bash from the Windows Start Menu (not from a directory). Enter

   pwd

   I later found out that this returns the location of your ssh keys. In my case this returned '/u/', which was a network drive mounted as "U:\" in my Windows account.

2. Type cd .ssh, then dir. This may list your currently existing id files, like id_rsa and id_rsa.pub. I deleted these files since I didn't need them anymore (you might want to skip this if you successfully used other SSH keys on your installation, e.g. for other Git Servers):

   rm id_rsa

   rm id_rsa.pub

3. Create a new id_rsa file (if you have an existing id_rsa file, you can also use another name, like id_rsa_gitlab_my_username or something like that. Add .pub to this name for the public key):

   vi id_rsa and press the 'i' on your keyboard to switch to text insertion mode. Now copy the content of your private key file (I had mine in C:\Users\my_windows_username.ssh\id_rsa and used Notepad++ to copy the complete content, Windows notepad works fine as well). Press Escape on your keyboard to exit text insertion mode, then enter ':' and 'x', then Enter to save the file. Repeat this for the public key file.

4. If you use multiple SSH keys or used another name for the id_rsa file, you should also create a 'config' file or copy the content of your existing configuration file:

   vi config

   (Again, press 'i', insert text, press ':', 'x', then Enter.) My file looks like this (use your server, user and SSH file name):

   #SCC Gitlab
       Host git.my_server.com
       HostName git.my_server.com
       User git
       IdentityFile ~/.ssh/id_rsa
   

Now my Git for Windows was able to push, pull and clone without problems again.

Answer 6

First, try this (changing your email address as needed)

 ssh-keygen -t rsa -b 4096 -C "you@yourdomain.com"

If you're creating using Cygwin, there might be confusion about the home directory, which is what happened for me, as I was referring to (copying to GitHub) an old/incorrect key from a different directory. So in case this happens for you, after creating the key, do:

$ explorer .

Which will pop up a windows explorer window, showing your full/absolute path. That's when I saw the ~ directory was actually my Cygwin directory

C:\Program Files\cygwin64\home\{your_username}\.ssh

I was then able to copy my private SSH key and paste in GitHub, and cloning, etc.. then worked.