GitHub: Permission denied (publickey). fatal: Could not read from remote repository

I´m having trouble with GitHub. I´ve playing around with a remote repository of Git.

When I now try to make any changes to the remote directory, i.e.

git remote show origin

or

git push -u origin master

I get this error

Permission denied (publickey). fatal: Could not read from remote repository.

Please make sure you have the correct access rights and the repository exists. Ulrichs-MacBook-Pro:coredatatest ulrichheinelt$ git push -u origin master Permission denied (publickey). fatal: Could not read from remote repository.

I would be happy, when I could start again with a new (empty) remote directory. Or is there a way, to fix this error?

This are my first steps with GitHub, started yesterday... Many thanks in advance!

Edit 1

my settings at https://github.com/UlliH/CoreDataTest/settings

...

Edit 2

too early happy :-(

After setting the SSH and GPG keys, the errors are still the same. :-/

Edit 3

I think that's right so, but still the same...

Solution 1:

1. Generate SSH key using ssh-keygen -t rsa -b 4096 -C "your email".
2. Copy the output of cat ~/.ssh/id_rsa.pub to your clipboard
3. Paste the above-copied output to the form at https://github.com/settings/ssh/new

Update: If you are still facing "ssh: connect to host github.com port 22: Connection timed out", then follow the below steps.

Check the connection, mostly it will time out

$ ssh -T [email protected]
ssh: connect to host github.com port 22: Connection timed out

Check the same by providing optional param port

$ ssh -T -p 443 [email protected]
Hi <user_name>! You've successfully authenticated, but GitHub does not provide shell access.

Update the SSH settings

$ vim ~/.ssh/config
# Add github in the know hosts
Host github.com
  Hostname ssh.github.com
  Port 443

Check the connection, mostly it will connect this time

$ ssh -T [email protected]
Hi <user_name>! You've successfully authenticated, but GitHub does not
provide shell access.

Solution 2:

• On your GitHub profile there is an Edit Profile button.
  It is located on top-right corner of the webpage.
• Press it and you will see left Personal Settings menu.
• Inside that menu find SSH and GPG keys option and press it.
• You will see an option New SSH key to add new key.

Solution 3:

1. generate your key

   ssh-keygen

2. Visualize your keys

   ls ~/.ssh

   id_rsa id_rsa.pub

3. Start the agent

   eval `ssh-agent`

4. Add your key to the agent

   ssh-add ~/.ssh/id_rsa