passwd [-l] [-k] [-y] [user]

DESCRIPTION

     Passwd changes the user's local, Kerberos, or YP 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.

     -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.

     -k    This option forces the change to affect the Kerberos database, even
           if the user has a password in the local database.  Once the pass-
           word has been verified, passwd communicates the new password infor-
           mation to the Kerberos authenticating host.

     -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.

     This is the behavior if no flags are specified: if Kerberos is active
     then passwd will talk to the Kerberos server (even if the user has an en-
     try in the local database.)  If the password is not in the local password
     database, then an attempt is made to use the YP database.

     To change another user's Kerberos password, one must first run kinit(1)
     followed by passwd(1).  The super-user is not required to provide a us-
     er'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
     /etc/passwd.conf    Configuration options

SEE ALSO

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

     Robert Morris, and Ken Thompson, UNIX password security.

HISTORY