HP OpenVMS Guide to System Security > Chapter 3 Using the System Responsibly

Types of Logins and Login Classes

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Logins can be either interactive or noninteractive. When you log in interactively, you enter an OpenVMS user name and a password. In noninteractive logins, the system performs the identification and authentication for you; you are not prompted for a user name and password. (The term interactive, as used here, differs from an interactive mode process defined by the DCL lexical function F$MODE(). For a description of the F$MODE function, see the HP OpenVMS DCL Dictionary.)

In addition to interactive and noninteractive logins, the OpenVMS operating system recognizes different classes of logins. How you log in to the system determines the login class to which you belong. Based on your login class, as well as the time of day or day of the week, the system manager controls your access to the system.

Logging In Interactively: Local, Dialup, and Remote Logins

Interactive logins include the following login classes:

  • Local

    You log in from a terminal connected directly to the central processor or from a terminal server that communicates directly with the central processor.

  • Dialup

    You log in to a terminal that uses a modem and a telephone line to make a connection to the computer system. Depending on the terminal that your system uses, you might need to execute a few additional steps. Your site security administrator can give you the necessary details.

  • Remote

    You log in to a node over the network by entering the DCL command SET HOST. For example, to access the remote node HUBBUB, you enter the following command:

    $ SET HOST HUBBUB

    If you have access to an account on node HUBBUB, you can log in to that account from your local node. You have access to the facilities on node HUBBUB, but you remain physically connected to your local node.

Logging In Using External Authentication

If you are an externally authenticated user, you log in by entering your LAN Manager user ID and password at the OpenVMS login prompts. Your LAN Manager user ID may or may not be the same as your OpenVMS user name.

See “Enabling External Authentication” for more information on logging in with external authentication enabled on your system.

Reading Informational Messages

When you log in from a terminal that is directly connected to a computer, the OpenVMS system displays informational system messages. Example 3-1 “Local Login Messages” illustrates most of these messages.

Example 3-1 Local Login Messages

WILLOW - A member of the Forest Cluster            [1]
Unlawful Access is Prohibited

Username: RWOODS
Password:
You have the following disconnected process: [2]
Terminal   Process name    Image name
VTA52: RWOODS (none)
Connect to above listed process [YES]: NO
Welcome to OpenVMS on node WILLOW        [3]
Last interactive login on Wednesday, 1-DEC-2001 10:20 [4]
Last non-interactive login on Monday, 30-NOV-2001 17:39 [5]
2 failures since last successful login [6]
You have 1 new mail message.        [7]
$

The preceding example illustrates the following:

  1. The announcement message identifies the node (and, if relevant, the cluster). It may also warn unauthorized users that unlawful access is prohibited. The system manager or security administrator can control both the appearance and the content of this message.

  2. A disconnected job message informs you that your process was disconnected at some time after your last successful login but is still available. You have the option of reconnecting to the old process and returning your process to its state before you were disconnected.

    The system displays the disconnected job message only when the following conditions exist:

    • The terminal where the interruption occurred is set up as a virtual terminal.

    • Your terminal is set up as one that can be disconnected.

    • During a recent session, your connection to the central processing unit (CPU) through that terminal was broken before you logged out.

    In general, the security administrator should allow you to reconnect to a disconnected job because this ability poses no special problems for system security. However, the security administrator can disable this function by changing the setup on terminals and by disabling virtual terminals on the system.

  3. A welcome message indicates the version number of the OpenVMS operating system that is running and the name of the node on which you are logged in. The system manager can choose a different message or can suppress the message entirely.

  4. The last successful interactive login message provides the time of the last completed login for a local, dialup, or remote login. (The system does not count logins from a subprocess whose parent was one of these types.)

  5. The last successful noninteractive login message provides the time the last noninteractive (batch or network) login finished.

  6. The number of login failures message indicates the number of failed attempts at login. (An incorrect password is the only source of login failure that is counted.) To attract your attention, a bell rings after the message appears.

  7. The new mail message indicates if you have any new mail messages.

A security administrator can suppress the announcement and welcome messages, which include node names and operating system identification. Because login procedures differ from system to system, it is more difficult to log in without this information.

The last login success and failure messages are optional. Your security administrator can enable or disable them as a group. Sites with medium-level or high-level security needs display these messages because they can indicate break-in attempts. In addition, by showing that the system is monitoring logins, these messages can be a deterrent to potential illegal users.

Each time you log in, the system resets the values for the last successful login and the number of login failures. If you access your account interactively and do not specify an incorrect password in your login attempts, you may not see the last successful noninteractive login and login failure messages.

When the System Logs In for You: Network and Batch Logins

Noninteractive logins include network logins and batch logins.

The system performs a network login when you start a network task on a remote node, such as displaying the contents of a directory or copying files stored in a directory on another node. Both your current system and the remote system must be nodes in the same network. In the file specification, you identify the target node and provide an access control string, which includes your user name and password for the remote node.

For example, a network login occurs when user Greg, who has an account on remote node PARIS, enters the following command:

$ DIRECTORY PARIS"GREG 8G4FR93A"::WORK2:[PUBLIC]*.*;*

This command displays a listing of all the files in the public directory on disk WORK2. It also reveals the password 8G4FR93A. A more secure way to perform the same task would be to use a proxy account on node PARIS. For an example of a proxy login, see “Using Proxy Login Accounts to Protect Passwords”.

The system performs a batch login when a batch job that you submitted runs. Authorization to build the job is determined at the time the job is submitted. When the system prepares to execute the job, the job controller creates a noninteractive process that logs in to your account. No password is required when the job logs in.