Secure Systems under NZ-COM
by Joe Wright
13 Jul 88
NZCPR.ZRL is a version of ZCPR34 with an extended and somewhat
elaborate security system built in. It works around the states
of DRVEC, MAXDRV, MAXUSR, WHEEL, Z3NDIR and PASSWORD.
A secure system under Z34 will usually have some directory areas
'open' to the user and others not. Try to think of the system as
a big box of secure directories with a smaller box of open
directories inside it.
User #
15
..
5
4
___________________
|
3 |
2 |
1 The Box |
0 |
|
Drive A B | C D E F ...
By setting MAXDRV to B (2) and MAXUSR to 3 we allow unrestricted
access from A0 through B3. Either DIR or DU references are
permitted within the box. All others are somehow protected. The
DRVEC word 'protects' any drive with its associated bit clear,
even if it is within the 'box'.
All directories outside the box are inaccessable unless they have
a name in the current Z3NDIR. With the WHEEL off, the user must
specify the directory by NAME. DU reference is not allowed. If
the NAME has an associated PASSWORD, the user must type this
correctly as well to gain any access to the directory.
With the WHEEL on, we are still restricted to those directories
with NAMES although DU reference to NAMED directories is allowed
and no password checking is required.
You can create a very secure system by reducing the 'box' to A0:
The user has access to all NAMED directories outside the box,
unless they are passworded and he doesn't know the password.
You may give certain users special access to other areas by
allowing CD to change the current Z3NDIR. You can allow 'almost'
anything without giving him the WHEEL (Don't give anyone the
WHEEL. That belongs to you).
I hope that Jay Sage is able to give a more coherent explanation
of all this in the up-coming ZCPR34 documentation. In the
meantime, simply try it out.
