The syntax of this message is specified in section The RPID field (as specified in section 2.2.1) of this message MUST be zeroed out.

The server MUST send this message to the client's RunspacePool if the server is trying to send secured data, and if the Session Key (section is not available yet. See section for more details.

The server sends this message to get the client's public key.

When this message is sent, the RunspacePool MUST be in an Opened state.