passwd(1) - NetBSD Manual Pages

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PASSWD(1)                   NetBSD Reference Manual                  PASSWD(1)


NAME

     passwd, yppasswd, kpasswd - modify a user's password


SYNOPSIS

     passwd [-l] [user]
     passwd [-y] [user]
     passwd [-4] [-k] [-i instance] [-r realm] [-u fullname] [user]
     passwd [-5] [-k] [-u fullname] [user]
     kpasswd [-4] [-k] [-i instance] [-r realm] [-u fullname] [user]
     kpasswd [-5] [-k] [-u fullname] [user]
     yppasswd [user]


DESCRIPTION

     passwd changes the user's local, YP, or kerberos password.  First, the
     user is prompted for their current password.  If the current password is
     correctly typed, a new password is requested.  The new password must be
     entered twice to avoid typing errors.

     The new password should be at least six characters long and not purely
     alphabetic.  Its total length must be less than _PASSWORD_LEN (currently
     128 characters).  Numbers, upper case letters and meta characters are en-
     couraged.

     All options may not be available on all systems.

     -l    This option causes the password to be updated only in the local
           password file.  When changing only the local password, pwd_mkdb(8)
           is used to update the password databases.

     -y    This forces the YP password database entry to be changed, even if
           the user has an entry in the local database.  The rpc.yppasswdd(8)
           daemon should be running on the YP master server.  yppasswd is the
           equivalent of passwd with the -y flag.

     -4    This option causes passwd to change the user's kerberos password,
           using the kerberos 4 admin protocol.

     -5    This option causes passwd to change the user's kerberos password,
           using the kerberos 5 admin protocol.

     -k    This option causes passwd to change the user's kerberos password,
           using either the kerberos 4 or kerberos 5 admin protocol.  If both
           kerberos 4 and kerberos 5 libraries and config files are installed
           on the host, kerberos 5 will be used to change the password.
           kpasswd is the equivalent of passwd with the -k flag.

     -i instance
           This option selects a non-default Kerberos 4 instance for the Ker-
           beros password to be changed.

     -r realm
           This option selects a non-default Kerberos 4 realm for the Kerberos
           password to be changed.

     -u fullname
           This option specifies the entire principal.instance@realm (for Ker-
           beros 4) or principal/instance@realm (for Kerberos 5) for the Ker-
           beros password to be changed.

     This is the behavior if no flags are specified: If Kerberos is active
     then passwd will talk to the Kerberos server, attempting to use Kerberos
     5, then Kerberos 4 protocols to change the password (even if the user has
     an entry in the local database.)  If Kerberos is unavailable, an attempt
     is made to use the YP database.  If the password is not in the YP
     database, then an attempt is made to use the local password database.

     The super-user is not required to provide a user's current password if
     only the local password is modified.

     Which type of cipher is used to encrypt the password information depends
     on the configuration in passwd.conf(5).  It can be different for local
     and YP passwords.


FILES

     /etc/master.passwd  The user database
     /etc/passwd         A Version 7 format password file
     /etc/passwd.XXXXXX  Temporary copy of the password file


SEE ALSO

     chpass(1), login(1), passwd(5), passwd.conf(5), pwd_mkdb(8), vipw(8)

     Robert Morris, and Ken Thompson, UNIX password security.


HISTORY

     A passwd command appeared in Version 6 AT&T UNIX.

NetBSD 1.5.3                     June 6, 1993                                2