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man page for passwd

passwd(1)						      General Commands Manual							 passwd(1)

NAME
passwd - change login password and associated attributes SYNOPSIS
[name] [name] [shell]] [name] [name] min] warn] max] name [shell]] [name] [shell]] [name] DESCRIPTION
The command modifies the password as well as the attributes associated with the login name. If name is omitted, it defaults to the invok- ing user's login name, which is determined using See getuid(2). Ordinary users can only change passwords corresponding to their login name. If an old password has been established, it is requested from the user. If valid, a new password is obtained. Once the new password is entered, it is determined if the old password has "aged" suffi- ciently. If password aging is not sufficient, the new password is rejected and terminates. See passwd(4). If password aging and construction requirements are met, the password is re-entered to ensure consistency. If the new copy differs, repeats the new password prompting cycle, at most twice. A superuser, whose effective user ID is zero, (see id(1) and su(1)), is allowed to change any password and is not forced to comply with password aging. On a trusted system, superusers are prompted for old passwords. On standard systems, superusers are not forced to comply with password construction requirements. Refer also to the section of this manpage. Null passwords can be created by entering a carriage return in response to the prompt for a new password. For the (local system) repository, if no file exists, then the encrypted password is stored in the password field of If the file exists, then the encrypted password is stored there, and an 'x' is added to the password field of The DCE repository is only available if Integrated Login has been configured. See auth.adm(1M). If Integrated Login has been configured, other considerations apply. A user with appropriate DCE privileges is capable of modifying a user's password, shell, gecos or home direc- tory and this is not dependent upon superuser privileges. If the repository is not specified, that is, [name], the password is changed in all existing repositories configured in If password options are used, and no repository is specified, the default repository is Options The following options are recognized: Modify the default shell for the user's login name in the password file. If the shell is not provided, the user will be prompted to enter the default login shell. The default password file is The option can be used to choose an alternate password file, where read and write permissions are required. This option is only available when using the repository, and it is not intended for trusted mode. Change the gecos information in the password file, which is used by the command. The user is prompted for each subfield: name, location, work phone, and home phone. Specify the repository to which the operation is to be applied. Supported repositories include and If repository is not specified, the default is Display some password attributes associated with the specified name. Superuser privilege is required if the repository is specified. The format of the display will be: or, if password aging information is not present where status means: and Display some password attributes for all users in the password file. The option must be used in conjunction with the option, with no name specified. For this is restricted to superuser. For a more complete display of attributes use the command. Privileged User Options A superuser can modify characteristics associated with the user name using the following options: Allow user to login without a password by deleting it. This option unlocks/activates the user account if found locked/deactivated. Force user to change password upon next login by expiring the current password. Modify the default home directory in the password file. Lock user account. This option replaces the encrypted password with *. Determine the minimum number of days, min, that must transpire before the user can change the password. If the option was used in a previous invocation of to immediately expire a password, the effect of the option is cancelled. The effect of the option is not cancelled if the option and option are specified on the same command line or if the system has been converted to a trusted system. Specify the number of days, warn, prior to the password expiring when the user will be notified that the password needs to be changed. This option is not allowed for systems that are not using shadow passwords. Determine the maximum number of days, max, a password can remain unchanged. The user must enter another password after that number of days has transpired, known as the password If the option was used in a previous invocation of to immediately expire a password, the effect of the option is cancelled, and the password will not expire until days. The effect of the option is not cancelled if the option and the option are specified on the same command line or if the system has been converted to a trusted system. The min and max arguments are each represented in units of days. These arguments will be rounded up to the nearest week on a standard HP- UX system. If the system is then converted to a trusted system, the number of days will be based on those weeks. If only one of the two arguments is supplied, and the other argument does not exist, then the number of days is set to zero. Password Aging The following description applies to all repositories except nis, which does not support password aging. The system requires a minimum time to elapse before a password can be changed. This prevents reuse of an old password within too brief a period of time. System warnings are displayed as the expiration time approaches. A password is no longer usable after a time period known as the password After the lifetime passes, the account is locked until it is re- enabled by a system administrator. Once unlocked, the user is forced to change the password before using the account. The and arguments are each represented in units of days. These arguments are rounded up to the nearest week on a standard system. If only one of the two arguments is supplied and the other argument does not exist, then the number of days is set to zero. Default values may be set in the file for the and options. See security(4). The attributes to select password aging defaults are: Password Construction Requirements Passwords must be constructed to meet the following requirements: o On a standard system, only the first eight characters of a password are significant. o The default minimum password length is six characters for non-root users on a standard system and for all users on a trusted system. See the description of the attribute in security(4) for information on how to change this restriction. o Characters must be from the 7-bit US-ASCII character set; letters from the English alphabet. o A password must contain at least two letters and at least one numeric or special character. o A password must differ from the user's login name and any reverse or circular shift of that login name. For comparison purposes, an uppercase letter and its corresponding lowercase equivalent are treated as identical. o A new password must differ from the old one by at least three characters (one character for non super user if changed by the super user in a trusted system). Repository Configuration The file specifies the repositories for which the password must be modified. The following configurations are supported: o passwd: files o passwd: files nis o passwd: compat (--> files nis) Authorizations When the Role-Based Access Control Extensions product (RBACExt) is installed, users with specific authorizations can be granted access to some of the options that normally require privileged user access when the files or NIS repositories are used. Refer to rbac(5) for more information on the Role-Based Access Control product. The following is a list of the required authorizations for running with particular options: Allows a user to modify the password of any non-root user. Allows a user to use the option to delete the password of any non-root user. Allows a user to use the option to display the password attributes of any user. Allows a user to use the option to expire the password of any non-root user. Allows a user to use the option (or to modify the gecos information of any non-root user. Allows a user to use the option to change the home directory of any non-root user. Allows a user to use the option to lock the account of any non-root user. Allows a user to use the option to specify the expiration time of a password of any non-root user. Allows a user to use the option to specify, for non-root users, the minimum number of days that must transpire before a password can be changed. Allows a user to use the option (or to change the default shell of any non-root user. Allows a user to use the option to specify, for non-root users, the number of days prior to a password's expiration that the user will be notified. Smart Card Login If the user account is configured to use a Smart Card, the user password is stored in the card. This password has characteristics identi- cal to a normal password stored on the system. The Smart Card must be inserted into the Smart Card reader. The user is prompted for a PIN instead of a password during authentication. The password is retrieved automatically from the Smart Card when a valid PIN is entered. Therefore, it is not necessary to know the pass- word, only the PIN. If the system retrieves a valid old password from the card, a new password is requested (twice). If the new password meets all require- ments, the system automatically overwrites the old password stored on the card with the new password. Therefore, the new dialog resembles: A Smart Card account can be shared among users. If one user modifies the password, other users must use the command to write the new pass- word onto their cards. The command is used to change the Smart Card PIN. SECURITY FEATURES
This section applies only to trusted systems. It describes additional capabilities and restrictions. When is invoked on a trusted system, the existing password is requested (if one is present). This initiates the password solicitation dia- log which depends upon the type of password generation (format policy) that has been enabled on the account doing the command. There are four possible options for password generation: Random syllables A pronounceable password made up of meaningless syllables. Random characters An unpronounceable password made up of random characters from the character set. Random letters An unpronounceable password made up of random letters from the alphabet. User-supplied A user-supplied password, subject to length and triviality restrictions. Passwords can be greater than eight characters, but it is recommended that they be less than 40 characters. System warnings are displayed if passwords lengths are either too long or short. The system administrator can specify a maximum password length guideline for the system generated options (random syllables, random characters, and random letters). The actual maximum password length depends upon several parameters in the authentication database and in the algorithm. The system requires a to elapse before a password can be changed. This prevents reuse of an old password within an undesirable period of time. A password expires after a period of time known as the System warnings are displayed as expiration time approaches. A password dies after a time period known as the After the lifetime passes, the account is locked until it is re-enabled by a system admin- istrator. Once unlocked, the user is forced to change the password before account use. The system administrator can enable accounts without passwords. If a user account is allowed to function without a password, the user can choose a null password by typing a carriage-return when prompted for a new password. The system administrator can enable the password history feature to discourage users from reusing previously used passwords. Refer to the security(4) manual page for detailed information on configurable attributes that affect the behavior of this command. The attribute for password history is: EXTERNAL INFLUENCES
International Code Set Support Characters from single-byte character code sets are supported in passwords. EXAMPLES
Change the password expiration date of to 42 days in the repository: Force to establish a new password on the next login which will expire in 70 days and prohibit the user from changing the password until 7 days have transpired: DEPENDENCIES
Pluggable Authentication Modules (PAM) PAM is an Open Group standard for user authentication, password modification, and account validation. In particular, is invoked to perform all functions related to This includes establishing and changing a password, using options, and displaying error messages. WARNINGS
Avoid password characters which have special meaning to the tty driver, such as # (erase) and @ (kill). You may not be able to login with these characters. Multiple superusers are allowed, but are strongly discouraged. That is because the system often stores user ID rather than user name. Hav- ing unique IDs for all users will guarantee a consistent mapping between user name and user ID. HP-UX 11i Version 3 is the last release to support trusted systems functionality. FILES
Standard password file used by HP-UX. Shadow password file. Protected password database used when system is converted to trusted system. Repository Configuration. Security defaults configuration file. SEE ALSO
chfn(1), id(1), login(1), su(1), logins(1M), pwconv(1M), auth.adm(1M), getuid(2), crypt(3C), passwd(4), security(4), shadow(4), auth(5), auth.dce(5), rbac(5). Pluggable Authentication Modules (PAM) pam_chauthtok(3), pam(3), pam.conf(4), pam_user.conf(4). HP-UX Smart Card Login scpin(1), scsync(1). STANDARDS CONFORMANCE
SVID2, SVID3, XPG2 passwd(1)

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