Skip site navigation (1)Skip section navigation (2)
Date:      Sun, 31 May 1998 05:22:28 -0700
From:      David Greenman <dg@root.com>
To:        Terry Lambert <tlambert@primenet.com>
Cc:        abial@nask.pl (Andrzej Bialecki), freebsd-hackers@FreeBSD.ORG
Subject:   Re: Signed executables, safe delete etc. 
Message-ID:  <199805311222.FAA07750@implode.root.com>
In-Reply-To: Your message of "Sun, 31 May 1998 09:34:54 -0000." <199805310934.CAA19826@usr04.primenet.com> 

next in thread | previous in thread | raw e-mail | index | archive | help
>> You can wonder what all this is for: it helps to ensure that no element of
>> the system has been changed without you knowing it. It could be performed
>> during startup of the system, and/or just before executing each binary (as
>> far as I understand it, ELF allows to put pretty arbitrary sections into
>> the binary). Moreover, this helps to ensure that the system won't boot
>> without proper authorization, and even if someone steals it, it could
>> refuse to give in (this would require encrypting the disk contents, of
>> course - that's why I said about bootblocks...).
>
>VMS will not mark an executable as executable unless the VMS linker is
>the program that created the file.
>
>In general, the VMS mechanism prevents programs without SYSPRIV from
>generating programs that can be loaded as executable.  The mechanism
>prevents the common case in BSD-land of LISP and other binaries that
>extend the data space of executables with code.
>
>Typically, this is a bad trade-off, favoring security over usability.

   Terry, sometimes I think we exist in different realities. First of all,
any user can set a file as executable in VMS. It does not require any special
privileges. Second, there is no "SYSPRIV" privilege. There is a "SYSPRV"
privilege, however, that allows the holder access system resources as if
he had a system UIC. One does not have to have a system UIC to change
file permissions (including the executable flag); all one needs is to be
the owner of the file - just like it is in Unix. Third, LISP works just fine
in VMS, including dynamic compilation and process extension.

-DG

David Greenman
Co-founder/Principal Architect, The FreeBSD Project

To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-hackers" in the body of the message



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199805311222.FAA07750>