PASSWD(4) — HP-UX

NAME

passwd − password file, pwd.h

DESCRIPTION

Passwd contains for each user the following information:

login name
encrypted password
numerical user ID
numerical group ID
reserved field which will be used for identification
initial working directory
program to use as shell

This is an ASCII file. Each field within each user’s entry is separated from the next by a colon. Each user is separated from the next by a new-line. If the password field is null, no password is demanded. If the shell field is null, /bin/sh is used.

This file resides in directory /etc. Because of the encrypted passwords, it can and does have general read permission and can be used, for example, to map numerical user IDs to names.

The encrypted password consists of 13 characters chosen from a 64-character set of "digits" described below, except when the password is null, in which case the encrypted password is also null. Login can be prevented by entering in the password field a character that is not part of the set of digits(e.g. ∗).

The characters used to represent "digits" are . for 0, / for 1, 0 through 9 for 2−11, A through Z for 12−37, and a through z for 38−63.

Password aging is effected for a particular user if his encrypted password in the password file is followed by a comma and a non-null string of characters from the above alphabet. (Such a string must be introduced in the first instance by the super-user.) This string defines the "age" needed to implement password aging.

The first character of the age, M say, denotes the maximum number of weeks for which a password is valid. A user who attempts to login after his password has expired will be forced to supply a new one. The next character, m say, denotes the minimum period in weeks which must expire before the password may be changed. The remaining characters define the week (counted from the beginning of 1970) when the password was last changed. (A null string is equivalent to zero.) M and m have numerical values in the range 0−63 that correspond to the 64-character set of "digits" shown above. If m = M = 0 (derived from the string . or ..) the user will be forced to change his password the next time he logs in (and the “age” will disappear from his entry in the password file). If m > M (signified, e.g., by the string ./) only the super-user will be able to change the password.

Pwd.h designates the broken out password file as obtained by getpwent(3C):

struct passwd {

	char	∗pw_name;
	char	∗pw_passwd;
	int	pw_uid;
	int	pw_gid;
	char	∗pw_age;
	char	∗pw_comment;
	char	∗pw_gecos;
	char	∗pw_dir;
	char	∗pw_shell;

};

It is suggested that the range 0-99 not be used for user and group ID’s (pw_uid and pw_gid in the above structure) so that IDs which may be assigned for system software do not conflict.

WARNINGS

The uid 17 is reserved for the Pascal Language operating system. The uid 18 is reserved for the BASIC Language operating system. These are operating systems for the Series 200 and Series 300 computers that can co-exist with HP-UX on the same disk. Using these uids for other purposes may inhibit file transfer and sharing.

HARDWARE DEPENDENCIES

Series 200, 300, 500:
The following fields have character limitations as noted:

the login name field can be no longer than 8 characters;

the initial working directory field can be no longer than 63 characters;

the program field can be no longer than 44 characters.

The results are unpredictable if these fields are longer than the limits specified above.

The reserved field, called pw_gcos in the data structures used by getpwent(3C), is reserved for future use. It currently may be used to contain any information the system manager desires, but such use may conflict with the use of future HP features. The correct operation of the system will never depend on this field, but some optional feature may specify its format and content.

FILES

/etc/passwd

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