INITIAL
BEFORE_HTML
BEFORE_HEAD
IN_HEAD
IN_HEAD
GENERIC_RCDATA
GENERIC_RCDATA
GENERIC_RCDATA
GENERIC_RCDATA
IN_HEAD
IN_HEAD
AFTER_HEAD
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
I           pam_unix — Module for traditional password authentication

════════════════════════════════════════════════════════════════════════════════

DESCRIPTION

This is the standard Unix authentication module. It uses standard calls from the
system's libraries to retrieve and set account information as well as
authentication. Usually this is obtained from the /etc/passwd and the
/etc/shadow file as well if shadow is enabled.

The account component performs the task of establishing the status of the user's
account and password based on the following shadow elements: expire,
last_change, max_change, min_change, warn_change. In the case of the latter, it
may offer advice to the user on changing their password or, through the
PAM_AUTHTOKEN_REQD return, delay giving service to the user until they have
established a new password. The entries listed above are documented in the
shadow(5) manual page. Should the user's record not contain one or more of these
entries, the corresponding shadow check is not performed.

The authentication component performs the task of checking the users credentials
(password). The default action of this module is to not permit the user access
to a service if their official password is blank.

A helper binary, unix_chkpwd(8), is provided to check the user's password when
it is stored in a read protected database. This binary is very simple and will
only check the password of the user invoking it. It is called transparently on
behalf of the user by the authenticating component of this module. In this way
it is possible for applications like xlock(1) to work without being setuid-root.
The module, by default, will temporarily turn off SIGCHLD handling for the
duration of execution of the helper binary. This is generally the right thing to
do, as many applications are not prepared to handle this signal from a child
they didn't know was fork()d. The noreap module argument can be used to suppress
this temporary shielding and may be needed for use with certain applications.

The maximum length of a password supported by the pam_unix module via the helper
binary is PAM_MAX_RESP_SIZE - currently 512 bytes. The rest of the password
provided by the conversation function to the module will be ignored.

The password component of this module performs the task of updating the user's
password. The default encryption hash is taken from the ENCRYPT_METHOD variable
from /etc/login.defs

The session component of this module logs when a user logins or leave the
system.

Remaining arguments, supported by others functions of this module, are silently
ignored. Other arguments are logged as errors through syslog(3).

OPTIONS

debug

        Turns on debugging via syslog(3).

audit

        A little more extreme than debug.

quiet

        Turns off informational messages namely messages about session open and
        close via syslog(3).

nullok

        The default action of this module is to not permit the user access to a
        service if their official password is blank. The nullok argument
        overrides this default.

nullresetok

        Allow users to authenticate with blank password if password reset is
        enforced even if nullok is not set. If password reset is not required
        and nullok is not set the authentication with blank password will be
        denied.

try_first_pass

        Before prompting the user for their password, the module first tries the
        previous stacked module's password in case that satisfies this module as
        well.

use_first_pass

        The argument use_first_pass forces the module to use a previous stacked
        modules password and will never prompt the user - if no password is
        available or the password is not appropriate, the user will be denied
        access.

nodelay

        This argument can be used to discourage the authentication component
        from requesting a delay should the authentication as a whole fail. The
        default action is for the module to request a delay-on-failure of the
        order of two seconds.

use_authtok

        When password changing enforce the module to set the new password to the
        one provided by a previously stacked password module (this is used in
        the example of the stacking of the pam_passwdqc module documented
        below).

authtok_type=type

        This argument can be used to modify the password prompt when changing
        passwords to include the type of the password. Empty by default.

nis

        NIS RPC is used for setting new passwords.

remember=n

        The last n passwords for each user are saved in /etc/security/opasswd in
        order to force password change history and keep the user from
        alternating between the same password too frequently. The MD5 password
        hash algorithm is used for storing the old passwords. Instead of this
        option the pam_pwhistory module should be used.

shadow

        Try to maintain a shadow based system.

md5

        When a user changes their password next, encrypt it with the MD5
        algorithm.

bigcrypt

        When a user changes their password next, encrypt it with the DEC C2
        algorithm.

sha256

        When a user changes their password next, encrypt it with the SHA256
        algorithm. The SHA256 algorithm must be supported by the crypt(3)
        function.

sha512

        When a user changes their password next, encrypt it with the SHA512
        algorithm. The SHA512 algorithm must be supported by the crypt(3)
        function.

blowfish

        When a user changes their password next, encrypt it with the blowfish
        algorithm. The blowfish algorithm must be supported by the crypt(3)
        function.

gost_yescrypt

        When a user changes their password next, encrypt it with the
        gost-yescrypt algorithm. The gost-yescrypt algorithm must be supported
        by the crypt(3) function.

yescrypt

        When a user changes their password next, encrypt it with the yescrypt
        algorithm. The yescrypt algorithm must be supported by the crypt(3)
        function.

rounds=n

        Set the optional number of rounds of the SHA256, SHA512, blowfish,
        gost-yescrypt, and yescrypt password hashing algorithms to n.

broken_shadow

        Ignore errors reading shadow information for users in the account
        management module.

minlen=n

        Set a minimum password length of n characters. The max. for DES crypt
        based passwords is 8 characters.

no_pass_expiry

        When set ignore password expiration as defined by the shadow entry of
        the user. The option has an effect only in case pam_unix was not used
        for the authentication or it returned authentication failure meaning
        that other authentication source or method succeeded. The example can be
        public key authentication in sshd. The module will return PAM_SUCCESS
        instead of eventual PAM_NEW_AUTHTOK_REQD or PAM_AUTHTOK_EXPIRED.

Invalid arguments are logged with syslog(3).

EXAMPLES

An example usage for /etc/pam.d/login would be:

# Authenticate the user
auth       required   pam_unix.so
# Ensure user's account and password are still active
account    required   pam_unix.so
# Change the user's password, but at first check the strength
# with pam_passwdqc(8)
password   required   pam_passwdqc.so config=/etc/passwdqc.conf
password   required   pam_unix.so use_authtok nullok yescrypt
session    required   pam_unix.so


AUTHOR

pam_unix was written by various people.
N_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
IN_BODY
AFTER_BODY
AFTER_AFTER_BODY
AFTER_AFTER_BODY
