11.3.3. Relayed authentication methods

For the server-side connection (between PSM and the target server), the following authentication methods are available.

Note

Even though these settings refer to the server-side connection, the client must support the selected authentication method and have it enabled. For example, to use publickey authentication on the server side, the client must support publickey authentication as well as provide a 'fake' publickey, even if a different authentication method is used on the client side.

The Connection Policy will ignore the settings for server-side authentication (set under Relayed authentication methods) if a Credential Store is used in the Connection Policy.

  • Password: Authentication based on username and password. The server will request a password from the user, even if a password-based authentication was already successful on the client-side.

  • Keyboard-Interactive: Authentication based on exchanging messages between the user and the server. This method includes authentication schemes like S/Key or TIS authentication. Note that depending on the configuration of the SSH server, password-based authentication can also require using the keyboard-interactive authentication method.

  • Public Key: Authentication based on public-private encryption keypairs. PSM supports the following public-key authentication scenarios:

    Balabit recommends using 2048-bit RSA keys (or stronger).

    • Agent: Allow the client to use agent-forwarding, and use its own keypair on the server-side. If this option is used, PSM requests the client to use its SSH agent to authenticate on the target server.

      Note

      Agent-based authentication can be combined with other authentication methods in the same Authentication Policy.

      If the provided keys are accepted for authentication, fallback to other authentication methods, for example password is not possible.

      Note

      To perform agent-based authentication on the target server, it is not required to enable the Agent-forwarding channel in the Channel Policy used by the connection. The Agent-forwarding channel is needed only to establish connections from the target server to other devices and authenticate using the agent running on the client.

    • Fix: Use the specified private key in the server-side connection. Select Relayed authentication methods > Public key > Server side private and public key > Fix > Private key, and click to upload the private key.

    • Publish to LDAP: PSM generates a keypair, and uses this keypair in the server-side connection. The public key of this keypair is also uploaded to the LDAP database set in the LDAP Server of the connection policy. That way the server can authenticate the client to the generated public key stored under the user's username in the LDAP database. Select Relayed authentication methods > Public key > Server side private and public key > Publish to LDAP.

      Note

      PSM generates a keypair for every user of the connection policy, not for every session.

  • X.509 certificate: Authentication based on X.509 certificates.PSM supports the following certificate-based authentication scenarios:

    Balabit recommends using 2048-bit RSA keys (or stronger).

    • Agent: Allow the client to use agent-forwarding, and use its own certificate on the server-side. If this option is used, PSM requests the client to use its SSH agent to authenticate on the target server.

      Note

      Agent-based authentication can be combined with other authentication methods in the same Authentication Policy.

      If the provided keys are accepted for authentication, fallback to other authentication methods, for example password is not possible.

      Note

      To perform agent-based authentication on the target server, it is not required to enable the Agent-forwarding channel in the Channel Policy used by the connection. The Agent-forwarding channel is needed only to establish connections from the target server to other devices and authenticate using the agent running on the client.

    • Fix: Use the specified private key and certificate in the server-side connection. Select Relayed authentication methods > X.509 certificate > Server side certificate > Fix, and click to upload the private key and the certificate.

    • Generate: PSM generates an X.509 certificate and the corresponding private key for every connection policy, and uses this certificate in the server-side connections. Select Relayed authentication methods > X.509 certificate > Server side certificate > Generate, and select the certificate authority to use for signing the generated certificates with from the Signing CA field. For details on configuring signing CAs, see Procedure 7.12, Signing certificates on-the-fly.

    • Publish to LDAP: PSM generates an X.509 certificate and the corresponding private key for every connection policy, and uses this certificate in the server-side connections. The certificate is also uploaded to the LDAP database set in the LDAP Server of the connection policy. That way the server can authenticate the client to the generated certificate stored under the user's username in the LDAP database. Select Relayed authentication methods > X.509 certificate > Server side certificate > Publish to LDAP, and select the certificate authority to use for signing the generated certificates with from the Signing CA field. For details on configuring signing CAs, see Procedure 7.12, Signing certificates on-the-fly.

      Note

      PSM generates a certificate for every connection policy, not for every session.