OSDN Docs (English)

Now, by simple operation, you can import your SSH key disclosed on GitHub as your OSDN account’s SSH key.

To add SSH key, you can conduct the SSH key settings from your account as usual. To import SSH key from GitHub, enter your GitHub account name in the SSH key’s additional modal window and then click the button to execute. It will be imported to the textarea reserved for entering SSH key, so confirm to add. During the login using your GitHub account, the account name will be automatically complemented.