|PASSWD(1)||General Commands Manual||PASSWD(1)|
passwd — modify a
passwd changes the user's local 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). A mixture
of both lower and uppercase letters, numbers, and meta-characters is
The quality of the password can be enforced by specifying an external checking program via the “passwordcheck” variable in login.conf(5).
The options are as follows:
If no flags are specified and the password is not in the local password database, then an attempt is made to use the YP database.
The superuser 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 login.conf(5). It can be different for local (“localcipher”) and YP (“ypcipher”) passwords. If none is specified, then blowfish with 6 rounds is used for local (“localcipher”) and old is used for YP (“ypcipher”) by default.
The password file is currently locked by another process;
passwd will keep trying to lock the password
file until it succeeds or you hit the interrupt character (control-C by
passwd is interrupted while trying
to gain the lock the password change will be lost.
If the process holding the lock was prematurely terminated the
lock file may be stale and
passwd will wait
forever trying to lock the password file. To determine whether a live
process is actually holding the lock, the admin may run the
$ fstat /etc/ptmp
If no process is listed, it is safe to remove the /etc/ptmp file to clear the error.
Robert Morris and Ken Thompson, Password security: a case history, Communications of the ACM, Issue 11, Volume 22, 594–597, Nov. 1979.
passwd command appeared in
Version 3 AT&T UNIX.
|May 19, 2014||OpenBSD-5.6|