/etc/opieaccess - OPIE database of trusted networks
The opieaccess file contains a list of networks that are considered
trusted by the system as far as security against passive attacks is
concerned. Users from networks so trusted will be able to log in using
OPIE responses, but not be required to do so, while users from networks
that are not trusted will always be required to use OPIE responses (the
default behavior). This trust allows a site to have a more gentle
migration to OPIE by allowing it to be non-mandatory for "inside" networks
while allowing users to choose whether they with to use OPIE to
protect their passwords or not.
The entire notion of trust implemented in the opieaccess file is a
major security hole because it opens your system back up to the same
passive attacks that the OPIE system is designed to protect you
against. The opieaccess support in this version of OPIE exists solely
because we believe that it is better to have it so that users who don't
want their accounts broken into can use OPIE than to have them prevented
from doing so by users who don't want to use OPIE. In any environment,
it should be considered a transition tool and not a permanent
fixture. When it is not being used as a transition tool, a version of
OPIE that has been built without support for the opieaccess file should
be built to prevent the possibility of an attacker using this file as a
means to circumvent the OPIE software.
The opieaccess file consists of lines containing three fields separated
by spaces (tabs are properly interpreted, but spaces should be used
instead) as follows:
Field Description
action "permit" or "deny" non-OPIE logins
address Address of the network to match
mask Mask of the network to match
Subnets can be controlled by using the appropriate address and mask.
Individual hosts can be controlled by using the appropriate address and
a mask of 255.255.255.255. If no rules are matched, the default is to
deny non-OPIE logins.
ftpd(8) login(1), opie(4), opiekeys(5), opiepasswd(1), opieinfo(1),
su(1),
Bellcore's S/Key was written by Phil Karn, Neil M. Haller, and John S.
Walden of Bellcore. OPIE was created at NRL by Randall Atkinson, Dan
McDonald, and Craig Metz.
S/Key is a trademark of Bell Communications Research (Bellcore).
OPIE is discussed on the Bellcore "S/Key Users" mailing list. To join,
send an email request to:
skey-users-request@thumper.bellcore.com
7th Edition January 10, 1995 OPIEACCESS(5)
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