NAME¶
pam_otpw - verify one-time passwords
SYNOPSIS¶
pam_otpw [
arguments ]
DESCRIPTION¶
OTPW is a one-time password authentication system. It compares entered
passwords with hash values stored in the user's home directory in the file
~/.otpw. Once a password was entered correctly, its hash value in
~/.otpw will be overwritten with hyphens, which disables its use in
future authentication. A lock file
~/.otpw.lock prevents that the same
password challenge is issued on several concurrent authentication sessions.
This helps to prevent an eavesdropper from copying a one-time password as it
is entered instantly into a second session, in the hope to get access by
sending the final newline character faster than the user could.
Both an authentication management and a session management function are offered
by this module. The authentication function asks for and verifies one-time
passwords. The session function prints a message after login that reminds the
user of the remaining number of one-time passwords.
ARGUMENTS¶
- debug
- Turn on debugging via syslog(3).
- nolock
- Disable locking. This option tells the authentication
function of pam_otpw.so to ignore any existing ~/.otpw.lock
lock file and not to generate any. With this option, pam_otpw.so
will never ask for several passwords simultaneously.
AUTHOR¶
The
OTPW package, which includes the
otpw-gen progam, has been
developed by Markus Kuhn. The most recent version is available from
<
http://www.cl.cam.ac.uk/~mgk25/otpw.html>.
SEE ALSO¶
otpw-gen(1), pam(8)