OpenSSH

OpenSSH is an Open Source (BSD licensed) suite of secure networking utilities based on the Secure Shell (SSH) protocol, which provides a secure channel over a potentially unsecured network.

How to connect over SSH

To connect from a Unix system to an OpenVMS system running OpenSSH, follow these steps: 1. On the Unix system, generate an ed25519 key pair:

ssh-keygen -t ed25519

2. Once ready, connect to the OpenVMS machine and navigate to the [.SSH] directory of the user:

set def [.ssh]

3. Open the AUTHORIZED_KEYS. file (or create a new one) and paste your public key there:

$ create authorized_keys.
ssh-ed25519 AAAAC3NzaC...
user@test

4. Use the following command for connecting from your Unix system:

ssh -o "KexAlgorithms +diffie-hellman-group1-sha1"
    -o HostKeyAlgorithms=+ssh-dss
    -o  PubkeyAcceptedAlgorithms=+ssh-dss 
    user@openvms_system 
    -i your_key_file

where user is the username on OpenVMS, openvms_system is the IP of your OpenVMS system running OpenSSH, and your_key_file is the path to the private key file on the Unix system generated in step 1.