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

Changing Your Password

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Changing passwords on a regular basis promotes system security. To change your password, enter the DCL command SET PASSWORD.

The system manager can allow you to select a password on your own or can require that you use the automatic password generator when you change your password. If you select your own password, note that the password must follow system restrictions on length and acceptability (see “Observing System Restrictions on Passwords”). For example, if your password choice is too short, the system displays the following message:

%SET-E-INVPWDLEN, invalid password length - password not changed

“Choosing a Password for Your Account” provides guidelines and examples for specifying secure passwords.

There is no restriction on how many times you can change your password in a given period of time.

Selecting Your Own Password

If your system manager does not require use of the automatic password generator, the SET PASSWORD command prompts you to enter the new password. It then prompts you to reenter the new password for verification, as follows:

$ SET PASSWORD
Return

New password:
Verification:

If you fail to enter the same password twice, the password is not changed. If you succeed in these two steps, there is no notification. The command changes your password and returns you to the DCL prompt.

Even though your security administrator may not require the password generator, you are strongly encouraged to use it to promote the security of your system. “Using Generated Passwords” describes how to use generated passwords.

Using Generated Passwords

If your system security administrator decides that you must let the system generate the password for you automatically, the system provides you with a list of password choices when you enter the DCL command SET PASSWORD. (When the system does not require generated passwords, add the /GENERATE qualifier to SET PASSWORD for a list of password choices.) The character sequence resembles native language words to make it easy to remember, but it is unusual enough to be difficult for outsiders to guess. Because system-generated passwords vary in length, they become even more difficult to guess.

NOTE: The password generator uses basic syllabic rules to generate words but has no real knowledge of any language. As a result, it can unintentionally produce words that are offensive.

In the following OpenVMS VAX example, the system automatically generates a list of passwords made up of random sequences of characters. The minimum password length for the user in the following example has been set to 8 in the UAF record.

$ SET PASSWORD
Old password:
Return
    [1]          
cigtawdpau    cig-tawd-pau    [2]
adehecun a-de-he-cun
ceebatorai cee-ba-to-rai
arhoajabad ar-hoa-ja-bad
Choose a password from this list, or press Return to get a new list [3]
New password:
Return
[4]
Verification:
Return
[5]
$       [6]

The preceding example illustrates the following:

  1. The user correctly specifies the old password and presses the Return key.

  2. The system responds with a list of five password choices ranging in length from 8 to 10 characters. There are representations of the same word divided into syllables to the right of each password choice. Usually the password that is easiest to pronounce is easiest to remember and, therefore, the best choice.

  3. The system informs the user that it is possible to request a new list by pressing the Return key in response to the prompt for a new password.

  4. The user enters one of the first five possible passwords and presses the Return key.

  5. The system recognizes that this password is one provided by the automatic password generator and responds with the verification prompt. The user enters the new password again and presses Return.

  6. The system changes the password and responds with the DCL prompt.

One disadvantage of automatic password generation is the possibility that you might not remember your password choice. However, if you dislike all the password choices in your list or think none are easy to remember, you can always request another list.

A more serious drawback of automatic password generation is the potential disclosure of password choices from the display the command produces. To protect your account, change your password in private. If you perform the change on a video terminal, clear the display of password choices from the screen after the command finishes. If you perform the change in a DECwindows environment, use the Clear Lines Off Top option from the Commands menu to remove the passwords from the screen recall buffer. If you use a printing terminal, properly dispose of all hardcopy output.

If you later realize that you failed to protect your password in these ways, change your password immediately. Depending on site policy or your own judgment concerning the length of time your account was exposed, you might decide to notify your security administrator that a security breach could have occurred through your account.

Changing a Secondary Password

To change a secondary password, use the DCL command SET PASSWORD/SECONDARY. You are prompted to specify the old secondary password and the new secondary password, just as in the procedure for changing the primary password. To remove a secondary password, press the Return key when you are prompted for a new password and verification.

You can change primary and secondary passwords independently, but both are subject to the same change frequency because they share the same password lifetime. See “Password and Account Expiration Times” for information on password lifetimes.

Changing Your Password As You Log In

Even if your current password has not yet expired, you can change your password when you log in to the system by including the /NEW_PASSWORD qualifier with your user name, as follows:

  WILLOW - A member of the Forest Cluster

Username: RWOODS/NEW_PASSWORD
Password:
Welcome to OpenVMS on node WILLOW
Last interactive login on Tuesday, 7-NOV-2001 10:20
Last non-interactive login on Monday, 6-NOV-2001 14:20

Your password has expired; you must set a new password to log in
New password:
Verification:

Entering the /NEW_PASSWORD qualifier after your user name forces you to set a new password immediately after login.