schrodinger.utils.sshconfig module¶

The sshconfig module contains code to configure Passwordless SSH.

Example:

Get the keypair to use using find_key_pair(..).
Check the keypair is okay before local host ssh setup using check_key_pair(..).
If the keypair is not okay, generate keypair in local system using configure_local_ssh_setup().
Setup passwordless SSH to desired host using install_remote_pubkey(..).

from schrodinger.utils import sshconfig

(priv_file, pub_file) = sshconfig.find_key_pair()
pub_key = sshconfig.check_key_pair(priv_file, pub_file)
if not pub_key:
    pub_key = sshconfig.configure_local_ssh_setup(priv_file, pub_file)
sshconfig.install_remote_pubkey("bobio", "rajagopa", "blah-blah", pub_key)

schrodinger.utils.sshconfig.find_key_pair()¶

Get the private and public key filename to use.

Returntype: tuple
Returns: A tuple containing private and public key filename.

schrodinger.utils.sshconfig.check_key_pair(priv_file, pub_file)¶

Check the given private and public key file to make sure they match. For Windows, the private key file is assumed to be in ppk understandable format.

Parameters

priv_file (string) – Private key file.
pub_file (string) – Public key file.

Returntype

string

Returns

base64 string containing public part of the key pair, on success empty string otherwise

schrodinger.utils.sshconfig.configure_local_ssh_setup(priv_file, pub_file)¶

Set up SSH key pair on your local machine. The private key is written to the file given. For windows this will be in plink understandable format and for non-windows this will be in OpenSSH format.

And the public key is written in <priv_file without extension>.pub in OpenSSH format.

Parameters

priv_file (string) – Private key file to write.

Returntype

string

Returns

base64 string containing public part of the key pair

Raises

OSError – if plink_keygen binary to convert OpenSSH to ppk doesn’t exist
RuntimeError – if the command to convert OpenSSH to ppk failed
IOError – if there was an error writing private/public key file
SSHException – if the private key file was invalid to get the public key.

schrodinger.utils.sshconfig.install_remote_pubkey(hostname, user, password, pubkey)¶

Setup passwordless ssh to the given remote host.

Parameters

hostname (string) – Setup passwordless ssh to this remote host.
user (string) – Specify the user to log in as on the remote machine.
password (string) – Password to use for logging into the remote machine.
pubkey (string) – Public key to cache in ‘authorized_keys’ of the remote machine.

Raises

paramiko.AuthenticationException – if the authentication failed.
paramiko.SSHException – if there was an error connecting or establishing an SSH session.
RuntimeError – if the command to cached public key at remote host fail or if the command to cache remote host’s fingerprint in registry fail (Windows).

schrodinger.utils.sshconfig.cache_hostname_plink(user, hostname)¶

Caches particular host name. This is intended to be run after we already have set up public key on remote host.

Parameters

hostname (string) – name of host
user (string) – username for remote host

schrodinger.utils.sshconfig.has_plink_ssh_host_key(prefix: str, hostname: str) → bool¶

Check PuTTY registry entries for hostname key.

Parameters

prefix – encryption type prefix (rsa2@22: or ssh-ed25519@22:)
hostname – name of machine for connecting

schrodinger.utils.sshconfig.hostname_in_registry(hostname)¶

If hostname is in cached registry, returns True. Only relevant to call on Windows.

Parameters: hostname (str) – name of host referred to in plink
Returns: bool

schrodinger.utils.sshconfig.known_hostname(hostname)¶

Checks if hostname has already been configured to use Passwordless SSH.

Parameters: hostname (str) – name of host
Returns: bool