passwd, netkey - change or verify user password
SYNOPSISpasswd [ username[@domain] ]
Passwd changes the invoker's Plan 9 password and/or APOP secret. The
Plan 9 password is used to login to a terminal while the APOP secret is
used for a number of external services: POP3, IMAP, and VPN access.
The optional argument specifies the user name and authentication domain
to use if different than the one associated with the machine passwd is
The program first prompts for the old Plan 9 password in the specified
domain to establish identity. It then prompts for changes to the pass‐
word and the secret. New passwords and secrets must be typed twice, to
forestall mistakes. New passwords must be sufficiently hard to guess.
They may be of any length greater than seven characters.
Netkey prompts for a password to encrypt network challenges. It is a
substitute for a SecureNet box.
These commands may be run only on a terminal, to avoid transmitting
clear text passwords over the network.
readnvram in authsrv(2), encrypt(2), cons(3), auth(8), securenet(8)
Robert Morris and Ken Thompson, ``UNIX Password Security,'' AT&T Bell
Laboratories Technical Journal Vol 63 (1984), pp. 1649-1672
Now that cpu connections are always encrypted, the only good reason to
require that these commands be run only on terminals is concern that
the CPU server might be subverted.