|
PASSWD(1) |
User Commands |
PASSWD(1) |
NAME
passwd - change login password and password attributes
SYNOPSIS
passwd [
-r files |
-r ldap |
-r nis |
-r nisplus] [
name]
passwd [-r files] [-egh] [name]
passwd [-r files] -s [-a]
passwd [-r files] -s [name]
passwd [-r files] [-d | -l | -u | -N] [-f] [-n min]
[-w warn] [-x max] name
passwd -r ldap [-egh] [name]
passwd [-r ldap ] -s [-a]
passwd [-r ldap ] -s [name]
passwd -r ldap [-d | -l | -u | -N] [-f] [-n min] [-w warn] [-x max] name
passwd -r nis [-egh] [name]
passwd -r nisplus [-egh] [-D domainname] [name]
passwd -r nisplus -s [-a]
passwd -r nisplus [-D domainname] -s [name]
passwd -r nisplus [-l | -u | -N] [-f] [-n min] [-w warn]
[-x max] [-D domainname] name
passwd -S [name]
DESCRIPTION
The
passwd command changes the password or lists password attributes associated with the user's login
name. Additionally, privileged users can use
passwd to install or change passwords and attributes associated with any login
name.
When used to change a password, passwd prompts everyone for their old password, if any. It then prompts for the new password twice. When the old password is entered, passwd checks to see if it has aged sufficiently. If aging is insufficient, passwd terminates; see pwconv(1M), nistbladm(1), and shadow(4) for additional information.
The pwconv command creates and updates /etc/shadow with information from /etc/passwd. pwconv relies on a special value of x in the password field of /etc/passwd. This value of xindicates that the password for the user is already in /etc/shadow and should not be modified.
If aging is sufficient, a check is made to ensure that the new password meets construction requirements. When the new password is entered a second time, the two copies of the new password are compared. If the two copies are not identical, the cycle of prompting for the new password is repeated for, at most, two more times.
Passwords must be constructed to meet the following requirements:
-
o
-
Each password must have PASSLENGTH characters, where PASSLENGTH is defined in /etc/default/passwd and is set to 6. Setting PASSLENGTH to more than eight characters requires configuring policy.conf(4) with an algorithm that supports greater than eight characters.
-
o
-
Each password must meet the configured complexity constraints specified in /etc/default/passwd.
-
o
-
Each password must not be a member of the configured dictionary as specified in /etc/default/passwd.
-
o
-
For accounts in name services which support password history checking, if prior password history is defined, new passwords must not be contained in the prior password history.
If all requirements are met, by default, the passwd command consults /etc/nsswitch.conf to determine in which repositories to perform password update. It searches the passwd and passwd_compat entries. The sources (repositories) associated with these entries are updated. However, the password update configurations supported are limited to the following cases. Failure to comply with the configurations prevents users from logging onto the system. The password update configurations are:
-
o
-
passwd: compat (==> files nis)
-
o
-
passwd: compat (==> files ldap)
passwd_compat: ldap
-
o
-
passwd: compat (==> files nisplus)
passwd_compat: nisplus
You can add the ad keyword to any of the passwd configurations in the above list. However, you cannot use the passwd command to change the password of an Active Directory (AD) user. If the ad keyword is found in the passwd entry during a password update operation, it is ignored. To update the password of an AD user, use the kpasswd(1) command.
Network administrators, who own the NIS+ password table, can change any password attributes. The administrator configured for updating LDAP shadow information can also change any password attributes. See ldapclient(1M).
When a user has a password stored in one of the name services as well as a local files entry, the passwd command updates both. It is possible to have different passwords in the name service and local files entry. Use passwd -r to change a specific password repository.
In the files case, super-users (for instance, real and effective uid equal to 0, see id(1M) and su(1M)) can change any password. Hence, passwd does not prompt privileged users for the old password. Privileged users are not forced to comply with password aging and password construction requirements. A privileged user can create a null password by entering a carriage return in response to the prompt for a new password. (This differs from passwd -d because the password prompt is still displayed.) If NIS is in effect, superuser on the root master can change any password without being prompted for the old NIS passwd, and is not forced to comply with password construction requirements.
If LDAP is in effect, superuser on any Native LDAP client system can change any password without being prompted for the old LDAP passwd, and is not forced to comply with password construction requirements.
Normally, passwd entered with no arguments changes the password of the current user. When a user logs in and then invokes su(1M) to become superuser or another user, passwd changes the original user's password, not the password of the superuser or the new user.
Any user can use the -s option to show password attributes for his or her own login name, provided they are using the -r nisplus argument. Otherwise, the -s argument is restricted to the superuser.
The format of the display is:
name status mm/dd/yy min max warn
or, if password aging information is not present,
name status
where
name
The login ID of the user.
status
The password status of
name.
The
status field can take the following values:
LK
This account is locked account. See Security.
NL
This account is a no login account. See Security.
NP
This account has no password and is therefore open without authentication.
PS
This account has a password.
mm/dd/yy
The date password was last changed for name. All password aging dates are determined using Greenwich Mean Time (Universal Time) and therefore can differ by as much as a day in other time zones.
min
The minimum number of days required between password changes for name. MINWEEKS is found in /etc/default/passwd and is set to NULL.
max
The maximum number of days the password is valid for name. MAXWEEKS is found in /etc/default/passwd and is set to NULL.
warn
The number of days relative to max before the password expires and the name are warned.
Security
passwd uses
pam(3PAM) for password change. It calls PAM with a service name
passwd and uses service module type
auth for authentication and password for password change.
Locking an account (-l option) does not allow its use for password based login or delayed execution (such as at(1), batch(1), or cron(1M)). The -N option can be used to disallow password based login, while continuing to allow delayed execution.
OPTIONS
The following options are supported:
-a
Shows password attributes for all entries. Use only with the -s option. name must not be provided. For the nisplus repository, this shows only the entries in the NIS+ password table in the local domain that the invoker is authorized to read. For the files and ldap repositories, this is restricted to the superuser.
-D domainname
Consults the passwd.org_dir table in domainname. If this option is not specified, the default domainname returned by nis_local_directory(3NSL) are used. This domain name is the same as that returned by domainname(1M).
-e
Changes the login shell. The choice of shell is limited by the requirements of getusershell(3C). If the user currently has a shell that is not allowed by getusershell, only root can change it.
-g
Changes the gecos (finger) information. For the files repository, this only works for the superuser. Normal users can change the ldap, nis, or nisplus repositories.
-h
Changes the home directory.
-r
Specifies the repository to which an operation is applied. The supported repositories are files, ldap, nis, or nisplus.
-s name
Shows password attributes for the login
name. For the
nisplus repository, this works for everyone. However for the
files and
ldap repositories, this only works for the superuser. It does not work at all for the
nis repository which does not support password aging.
The output of this option, and only this option is Stable and parsable. The format is
username followed by white space followed by one of the following codes.
New codes might be added in the future so code that parses this must be flexible in the face of unknown codes. While all existing codes are two characters in length that might not always be the case.
The following are the current status codes:
LK
Account is locked for UNIX authentication. passwd -l was run or the authentication failed RETRIES times.
NL
The account is a no login account. passwd -N has been run.
NP
Account has no password. passwd -d was run.
PS
The account probably has a valid password.
UN
The data in the password field is unknown. It is not a recognizable hashed password or any of the above entries. See crypt(3C) for valid password hashes.
Privileged User Options
Only a privileged user can use the following options:
-d
Deletes password for
name and unlocks the account. The login
name is not prompted for password. It is only applicable to the
files and
ldap repositories.
If the
login(1) option
PASSREQ=YES is configured, the account is not able to login.
PASSREQ=YES is the delivered default.
-f
Forces the user to change password at the next login by expiring the password for name.
-l
Locks password entry for name. See the -d or -u option for unlocking the account.
-N
Makes the password entry for name a value that cannot be used for login, but does not lock the account. See the -d option for removing the value, or to set a password to allow logins.
-n min
Sets minimum field for name. The min field contains the minimum number of days between password changes for name. If min is greater than max, the user can not change the password. Always use this option with the -x option, unless max is set to −1 (aging turned off). In that case, min need not be set.
-u
Unlocks a locked password for entry name. See the -d option for removing the locked password, or to set a password to allow logins.
-w warn
Sets warn field for name. The warn field contains the number of days before the password expires and the user is warned. This option is not valid if password aging is disabled.
-x max
Sets maximum field for name. The max field contains the number of days that the password is valid for name. The aging for name is turned off immediately if max is set to −1.
-S
Read the password from standard input (pipe).
OPERANDS
The following operand is supported:
name
User login name.
ENVIRONMENT VARIABLES
If any of the
LC_* variables, that is,
LC_CTYPE,
LC_MESSAGES,
LC_TIME,
LC_COLLATE,
LC_NUMERIC, and
LC_MONETARY (see
environ(5)), are not set in the environment, the operational behavior of
passwd for each corresponding locale category is determined by the value of the
LANG environment variable. If
LC_ALL is set, its contents are used to override both the
LANG and the other
LC_* variables. If none of the above variables is set in the environment, the
C (U.S. style) locale determines how
passwd behaves.
LC_CTYPE
Determines how passwd handles characters. When LC_CTYPE is set to a valid value, passwd can display and handle text and filenames containing valid characters for that locale. passwd can display and handle Extended Unix Code ( EUC) characters where any individual character can be 1, 2, or 3 bytes wide. passwd can also handle EUC characters of 1, 2, or more column widths. In the C locale, only characters from ISO 8859-1 are valid.
LC_MESSAGES
Determines how diagnostic and informative messages are presented. This includes the language and style of the messages, and the correct form of affirmative and negative responses. In the C locale, the messages are presented in the default form found in the program itself (in most cases, U.S. English).
EXIT STATUS
The
passwd command exits with one of the following values:
0
Success.
1
Permission denied.
2
Invalid combination of options.
3
Unexpected failure. Password file unchanged.
4
Unexpected failure. Password file(s) missing.
5
Password file(s) busy. Try again later.
6
Invalid argument to option.
7
Aging option is disabled.
8
No memory.
9
System error.
10
Account expired.
FILES
/etc/default/passwd
Default values can be set for the following flags in
/etc/default/passwd. For example:
MAXWEEKS=26
DICTIONDBDIR
The directory where the generated dictionary databases reside. Defaults to
/var/passwd.
If neither
DICTIONLIST nor
DICTIONDBDIR is specified, the system does not perform a dictionary check.
DICTIONLIST
DICTIONLIST can contain list of comma separated dictionary files such as
DICTIONLIST=file1,
file2,
file3. Each dictionary file contains multiple lines and each line consists of a word and a NEWLINE character (similar to
/usr/share/lib/dict/words.) You must specify full pathnames. The words from these files are merged into a database that is used to determine whether a password is based on a dictionary word.
If neither
DICTIONLIST nor
DICTIONDBDIR is specified, the system does not perform a dictionary check.
To pre-build the dictionary database, see
mkpwdict(1M).
HISTORY
Maximum number of prior password history to keep for a user. Setting the HISTORY value to zero (0), or removing the flag, causes the prior password history of all users to be discarded at the next password change by any user. The default is not to define the HISTORY flag. The maximum value is 26. Currently, this functionality is enforced only for user accounts defined in the files name service (local passwd(4)/shadow(4)).
MAXREPEATS
Maximum number of allowable consecutive repeating characters. If MAXREPEATS is not set or is zero (0), the default is no checks
MAXWEEKS
Maximum time period that password is valid.
MINALPHA
Minimum number of alpha character required. If MINALPHA is not set, the default is 2.
MINDIFF
Minimum differences required between an old and a new password. If MINDIFF is not set, the default is 3.
MINDIGIT
Minimum number of digits required. If MINDIGIT is not set or is set to zero ( 0), the default is no checks. You cannot be specify MINDIGIT if MINNONALPHA is also specified.
MINLOWER
Minimum number of lower case letters required. If not set or zero (0), the default is no checks.
MINNONALPHA
Minimum number of non-alpha (including numeric and special) required. If MINNONALPHA is not set, the default is 1. You cannot specify MINNONALPHA if MINDIGIT or MINSPECIAL is also specified.
MINWEEKS
Minimum time period before the password can be changed.
MINSPECIAL
Minimum number of special (non-alpha and non-digit) characters required. If MINSPECIAL is not set or is zero (0), the default is no checks. You cannot specify MINSPECIAL if you also specify MINNONALPHA.
MINUPPER
Minimum number of upper case letters required. If MINUPPER is not set or is zero ( 0), the default is no checks.
NAMECHECK
Enable/disable checking or the login name. The default is to do login name checking. A case insensitive value of no disables this feature.
PASSLENGTH
Minimum length of password, in characters.
WARNWEEKS
Time period until warning of date of password's ensuing expiration.
WHITESPACE
Determine if white space characters are allowed in passwords. Valid values are YES and NO. If WHITESPACE is not set or is set to YES, white space characters are allowed.
/etc/oshadow
Temporary file used by passwd, passmgmt and pwconv to update the real shadow file.
/etc/passwd
Password file.
/etc/shadow
Shadow password file.
/etc/shells
Shell database.
ATTRIBUTES
See
attributes(5) for descriptions of the following attributes:
|
ATTRIBUTE TYPE |
ATTRIBUTE VALUE |
|
|
|
CSI |
Enabled |
|
|
|
Interface Stability |
See below. |
The human readable output is Uncommitted. The options are Committed.
SEE ALSO
at(1), batch(1), finger(1), kpasswd(1), login(1), nistbladm(1), cron(1M), domainname(1M), eeprom(1M), id(1M), ldapclient(1M), mkpwdict(1M), passmgmt(1M), pwconv(1M), su(1M), useradd(1M), userdel(1M), usermod(1M), crypt(3C), getpwnam(3C), getspnam(3C), getusershell(3C), nis_local_directory(3NSL), pam(3PAM), loginlog(4), nsswitch.conf(4), pam.conf(4), passwd(4), policy.conf(4), shadow(4), shells(4), attributes(5), environ(5), pam_authtok_check(5), pam_authtok_get(5), pam_authtok_store(5), pam_dhkeys(5), pam_ldap(5), pam_unix_account(5), pam_unix_auth(5), pam_unix_session(5)
NOTES
The
pam_unix(5) module is no longer supported. Similar functionality is provided by
pam_unix_account(5),
pam_unix_auth(5),
pam_unix_session(5),
pam_authtok_check(5),
pam_authtok_get(5),
pam_authtok_store(5),
pam_dhkeys(5), and
pam_passwd_auth(5).
The nispasswd and ypasswd commands are wrappers around passwd. Use of nispasswd and ypasswd is discouraged. Use passwd -r repository_name instead.
NIS+ might not be supported in future releases of the Solaris operating system. Tools to aid the migration from NIS+ to LDAP are available in the current Solaris release. For more information, visit http://www.sun.com/directory/nisplus/transition.html.
Changing a password in the files and ldap repositories clears the failed login count.
Changing a password reactivates an account deactivated for inactivity for the length of the inactivity period.
If /etc/shells is present, and is corrupted, it may provide an attack vector that would compromise the system. The getusershell(3c) library call has a pre-vetted list of shells, so /etc/shells should be used with caution.
Input terminal processing might interpret some key sequences and not pass them to the passwd command.
An account with no password, status code NP, might not be able to login. See the login(1) PASSREQ option.