Which public ssh key was used to connect to git

Question

I have generated several ssh keys and have placed in git server. Is it possible somehow to know which ssh key was used while executing git clone command?

Answer 1

You can see your currently active ssh-key by ssh-add command.

$ ssh-add             # show active ssh-key file path

You can customize it also. Open ~/.ssh/config file and find Host <hostname> , then the IdentifyFile points the id_rsa file that git clone is using for that <hostname> .

$ cat ~/.ssh/config

// sample output
Host bitbucket.org
User git
Hostname bitbucket.org
PreferredAuthentications publickey
IdentityFile ~/.ssh/id_rsa

Here, As git clone git@bitbucket.org:<user>/<repo>.git is using bitbucket.org Host and user git , so ~/.ssh/id_rsa file is using as ssh-key and you need to save ~/.ssh/id_rsa.pub in BitBucket account.

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Now, if you add another ssh-key in ~/.ssh/config file like -

Host bitbucket-alice
User git
Hostname bitbucket.org
PreferredAuthentications publickey
IdentitiesOnly yes
IdentityFile ~/.ssh/alice

You need to clone with git clone git@bitbucket-alice:<user>/<repo>.git and it will use ~/.ssh/alice and you need to add ~/.ssh/alice.pub in your BitBucket account.

Answer 2

You can look into the authentication log file of your Git server. In the local Git clone you have no chance.