SilcPrivateMessageKeys
    silc_client_list_private_message_keys(SilcClient client,
                                          SilcClientConnection conn,
                                          SilcUInt32 *key_count);

    Returns array of set private message keys associated to the connection
    `conn'. Returns allocated SilcPrivateMessageKeys array and the array
    count to the `key_count' argument. The array must be freed by the caller
    by calling the silc_client_free_private_message_keys function. Note:
    the keys returned in the array is in raw format. It might not be desired
    to show the keys as is. The application might choose not to show the keys
    at all or to show the fingerprints of the keys.