You want to authenticate between an OpenSSH client and an SSH2 server (i.e., SSH Secure Shell from SSH Communication Security) using an existing OpenSSH-format key.
Export your OpenSSH key to create an SSH2-format public key. If your OpenSSH private key is ~/.ssh/id_dsa:
$ cd ~/.ssh $ ssh-keygen -e -f id_dsa > mykey-ssh2.pub
Copy the public key to the SSH2 server:
$ scp mykey-ssh2.pub remoteuser@remotehost:
Log into the SSH2 server and install the public key, then log out:
$ ssh -l remoteuser remotehost Password: ******** remotehost$ mkdir -p ~/.ssh2 If it doesn't already exist remotehost$ chmod 700 ~/.ssh2 remotehost$ mv mykey-ssh2.pub ~/.ssh2/ remotehost$ cd ~/.ssh2 remotehost$ echo "Key mykey-ssh2.pub" >> authorization (Appending) remotehost$ chmod 600 mykey-ssh2.pub authorization remotehost$ logout
Now log in via public-key authentication:
$ ssh -l remoteuser remotehost Enter passphrase for key '/home/smith/.ssh/id_dsa': *******
OpenSSH's ssh-keygen converts OpenSSH-style keys into SSH2-style using the -e (export) option. Recall that SSH2 uses the authorization file, as explained in the sidebar, SSH-2 Key File Formats.