SSH Requirements

The N1 Grid Service Provisioning System 5.0 requires the following SSH capabilities:

• Remote command invocation through ssh

• Public-private key authentication

• Support for BatchMode yes interaction, which is the ability to invoke the ssh command without interaction from an operator

If you are using the ssh-agent, the following SSH capabilities are required:

• Support for ssh-agent.

• Support for ssh-agent forwarding in SSH. Use the -A option in Open SSH.

The following capabilities are helpful when configuring machines for SSH connectivity, but are not requirements:

• Force allocate a tty when doing remote command invocation. Use the -t option in OpenSSH.

• Kill the ssh agent. Use the -k option for the ssh-agent command in OpenSSH.

• Generate an RSA key for higher security. Use the -t rsa in OpenSSH.

Review the following checklist to determine whether an implementation of SSH meets the requirements of the N1 Grid Service Provisioning System 5.0.

• The ssh-keygen command must generate a public-private key pair that can be used for authenticating SSH invocations.

• On the specified host, without prompting for any extra information to exchange host keys, obtain a password, etc., when the private key used for authentication was created without a password or with an empty password, the ssh command must be able to execute the following:

  % ssh –o `BatchMode yes' hostname

• After hopping from the current host to host1 to host2 to host3, on host3 with the ssh-agent running on the current host, uploaded with a private key created with a non-empty password, without prompting for any extra information to exchange host keys, obtain a password, etc., the ssh command must be able to execute the following:

  % ssh –o `BatchMode yes' –A host1 ssh –o `BatchMode yes' –A host2 ssh –o `BatchMode yes' host3

• The ssh command must be able to correctly pipe its own standard input, output, and error streams to the command being executed on the remote machine.

• The ssh-add command must be able to upload private keys with non-empty passwords into the ssh-agent so that the private keys can be used for authentication.