GitLab SSH Permission denied (publickey)

Question

I've followed the Gitlab instructions to set up an SSH key.

After everything is completed, I test my settings with

ssh -T git@gitlab.com

but then I got an error with

git@gitlab.com: Permission denied (public key).

I also tried ssh -Tvvv git@gitlab.com to find out the problems, as below. But I can't figure out how to fix it, does anybody have an idea, or could share suggestions? Thank you very much!

OpenSSH_8.1p1, LibreSSL 2.7.3
.......
debug3: send packet: type 50
debug3: receive packet: type 51
debug1: Authentications that can continue: publickey
debug3: start over, passed a different list publickey
debug3: preferred publickey,keyboard-interactive,password
debug3: authmethod_lookup publickey
debug3: remaining preferred: keyboard-interactive,password
debug3: authmethod_is_enabled publickey
debug1: Next authentication method: publickey
debug1: Trying private key: /Users/brandon/.ssh/id_rsa
debug3: no such identity: /Users/brandon/.ssh/id_rsa: No such file or directory
debug1: Trying private key: /Users/brandon/.ssh/id_dsa
debug3: no such identity: /Users/brandon/.ssh/id_dsa: No such file or directory
debug1: Trying private key: /Users/brandon/.ssh/id_ecdsa
debug3: no such identity: /Users/brandon/.ssh/id_ecdsa: No such file or directory
debug1: Offering public key: /Users/brandon/.ssh/id_ed25519 ED25519 SHA256:uOKjKpgEmnKqrFAS05Ccy8+B3Uw0kzSpurUpOgH0l3k
debug3: send packet: type 50
debug2: we sent a publickey packet, wait for reply
debug3: receive packet: type 51
debug1: Authentications that can continue: publickey
debug1: Trying private key: /Users/brandon/.ssh/id_xmss
debug3: no such identity: /Users/brandon/.ssh/id_xmss: No such file or directory
debug2: we did not send a packet, disable method
debug1: No more authentication methods to try.
git@gitlab.com: Permission denied (publickey).

Thank you for your patience in reading my post.

Answer 1

Thank you, I solved it! Since its server is from our university so after changing ssh -T git@gitlab.com to ssh -T git@theuniversitylink.com it works.

I appreciate a lot for all the sharing and helps.

Answer 2

set up with id_ed25519.pub key, and it stored in /Users/brandon/.ssh

Try first with a more classic rsa key, for testing!

ssh-keygen -t rsa -P "" -m PEM 

Copy the /Users/brandon/.ssh/id_rsa.pub to your GitLab SSH account settings, and check if ssh -T git@gitlab.com works.

Answer 3

I fixed it this way on macos:

ssh-add ~/.ssh/id_ed25519.pub