This document is written for the sole purpose to explain what the Trustix
Secure Linux distribution (TSL) is all about. If you want to know more about
the TSL distribution, feel free to read on, and be enlightened.
The purpose of the TSL-project is to create a high quality, open source
operating system designed for the server share of the PC market. This is done
by using carefully selected components from well-known reliable sources like
the GNU Project and the Linux kernel in addition to software created
specifically for TSL.
An other goal is to keep the default TSL install as clean and small as
possible. Many users in the TSL community use TSL as a base, and add what
they need on top of the TSL installation. It is essential that we maintain
this quality.
This document is licensed by the GNU General Public License, and a
verbatim copy of the license is attached.
The typical TSL user, is an experienced Linux system administrator, thus
educated when it comes to security, and capable to make most changes he/she
feel is necessary to the installed system. Also many of the TSL users use TSL
as a base for more obscure software, as the distribution is regarded clean,
stable and secure.
TSL is, generally speaking, not targeted at newbie users that doesn't at all
know their way around Linux. However, TSL is a great foundation for most
server configurations, and being a clean Linux distribution, with an active
user community, TSL is quite a usable starting point in the Linux server
learning process. The distribution include the most commonly used services or
their secure counterparts.
In addition to being targeted for the server market, TSL is targeted as a
secure distribution.
TSL provides:
In line with its mission to produce the most secure
distribution of Linux available, Trustix Secure Linux now incorporates
IBM stack protection. This technology is of particular
importance to enterprise server deployments where safeguarding data is
of paramount concern.
Extending the Stackguard compiler, Stack Protection defends systems
from buffer overflows by inserting protection code into an application
at the point of compilation.
It detects and defeats stack smashing attacks by protecting the
return address on the stack from being altered. The ``XOR Random
canary'' method places the xor value of the return address and a random
number next to the return address when a function is called and then
checks that the value is preserved before the function returns.
This delivers effective buffer overflow detection and avoids the
corruption of pointers by re-ordering local variables to place buffers
after pointers.
Such protection is achieved with miniscule performance overhead
whilst producing programs that are inherently hardened against Stack
Smashing Attacks.
- Secure installation media
TSL online available installation media is always synchronized with the
distribution tree. This means that you will have a secure, updated system
right from the beginning.
TSL is shipped with the swup software updater tool, which gives
an intuitive and fast interface to rpm(The Red hat Package
Manager). Via the swup tool one can install new packages, or
update the system with one simple command, remotely.
This is something every Linux distribution really should prioritize, but the
fact remains; most distributions is not fast enough. The TSL team consider it
crucial to be amongst the first vendors to update packages when a security
issue has raised.
The last main distribution target is stability. By not falling into the
dark pit of staying up to date with the latest cvs updates, but rather
back port security fixes if necessary, TSL is one of the most stable
distributions on the market.
There are no reason what so ever to down size the need for security in
todays computer driven community. However, there will always be a point
where stronger security will destroy the usability of a product, and TSL
keeps this balance, even when being on the edge.
It's quite possible to create a system that is so obscure that almost no
attacker manages to find a usable entrance. But, security by obscurity
have never been a goal for TSL. TSL is a Linux distribution, Linux is
what the TSL community demands, and Linux is what they get.
The TSL approach to security is quite simple and can be summarized into
these main points:
- Quick security updates
- The TSL team consider the necessity of being updated at any time crucial.
With this in mind they developed the swup software updater tool.
swup enables users to automatic keep up to date with the current
security and bug fix updates. swup is one of the most versatile update
tools in the Linux world.
- Stack protection - delivers effective buffer overflow detection and avoids the
corruption of pointers by re-ordering local variables to place buffers
after pointers.
- Always updated installation media
- The usability of the distribution is also a main criteria for the TSL
team. To achieve this the downloadable installation media are always up
to date with the rest of the distribution, thus making life of the user
that much simpler.
- Secure default installation
- Even if the user choose to install every package in the TSL
distribution, the installed system will not enable any services to
listen on input from the outside world, thus making it virtually
impossible to break in to. Following this aspect, the TSL distribution
have never had a remote hole in the default installation.
- Secure default configurations
- TSL supplies secure default configurations to all included services
to ensure that the users wont get any unwanted surprises. This makes it
much easier for new users to explore their system, as the chance of
doing something very wrong, security wise is greatly reduced.
- Open Source Projects
- TSL is totally based on open source software. The positive results in
using open source software has been quite under estimated over the
years, but today there can be no doubt in the fact that the open source
development model is the most secure development model known to man.
Let's face it; the, at any given time considered, stable TSL release, is
never cutting edge. And it should never be!
All experience show that cutting edge technology always have major or
minor problems that the older, better tested software already have
resolved. These problems can be security related as well, but cutting
edge technology is never stable. The TSL team consider cutting
edge not usable on a stable production server.
However, TSL is a great build platform, and if cutting edge is what you
need, then you probably wont have any problems doing so on a TSL base.
The customers need for stability and security should always be in the
spotlight when maintaining a secure Linux distribution.
To get stability one must use well tested software, and to ensure
security, this software must be up to date. The TSL team takes pride in
keeping the various TSL releases up to date, at all times. This is why
the 1.01 release is still supported with security updates, more than two
years after the initial release.
Being able to foresee a given result is the main key to successfully
employ scalability on multiple hosts. Any system administrator that have
the need for similar setups on different physical hosts knows this.
The updated TSL installation media and the swup software updater
is great tools to ensure a consistent server environment. But this is not
the grand total of what TSL offers.
It is possible to create predefined custom installation medias based upon
TSL, which makes it possible to ensure the same setup on numerous
servers, only having to add very little information such as ip addresses
and passwords.
By doing so the administrator can easily reinstall servers with complex
server setups in a minimum of time, ensuring very low down time if a
hardware system breakdown should occur.
The TSL user community consists of a vast number of experienced Linux
administrators. These users are able to answer close to any question related to
TSL, implementing means of security on various hardware, and vice versa. The
best way to collect information about your TSL installation, is by joining the
tsl-discuss mailing list.
TSL have two official mailing lists:
- tsl-discuss
- General discussion about installation and usage of TSL.
- tsl-announce
- Official announcements from the TSL team.
Information about subscription are found at this address:
http://lists.trustix.org/mailman/listinfo/
The official forum for community discussions is located on http://www.trustix.org/forum/
The official community documentation effort is located on http://www.trustix.org/wiki/
The TSL project home page:
http://www.tslng.net/
The swup and rdfgen development home page:
http://swup.tslng.org
The TSL development policy:
http://doc.tslng.org/policy/policy.html
Please visit the pages of Comodo Trustix Limited for commercial offerings: http://www.trustix.com
GNU GENERAL PUBLIC LICENSE Version 2, June 1991
Copyright (C) 1989, 1991 Free Software Foundation, Inc.
59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
Everyone is permitted to copy and distribute verbatim copies
of this license document, but changing it is not allowed.
Preamble
The licenses for most software are designed to take away your
freedom to share and change it. By contrast, the GNU General Public
License is intended to guarantee your freedom to share and change free
software--to make sure the software is free for all its users. This
General Public License applies to most of the Free Software
Foundation's software and to any other program whose authors commit to
using it. (Some other Free Software Foundation software is covered by
the GNU Library General Public License instead.) You can apply it to
your programs, too.
When we speak of free software, we are referring to freedom, not
price. Our General Public Licenses are designed to make sure that you
have the freedom to distribute copies of free software (and charge for
this service if you wish), that you receive source code or can get it
if you want it, that you can change the software or use pieces of it
in new free programs; and that you know you can do these things.
To protect your rights, we need to make restrictions that forbid
anyone to deny you these rights or to ask you to surrender the rights.
These restrictions translate to certain responsibilities for you if you
distribute copies of the software, or if you modify it.
For example, if you distribute copies of such a program, whether
gratis or for a fee, you must give the recipients all the rights that
you have. You must make sure that they, too, receive or can get the
source code. And you must show them these terms so they know their
rights.
We protect your rights with two steps: (1) copyright the software, and
(2) offer you this license which gives you legal permission to copy,
distribute and/or modify the software.
Also, for each author's protection and ours, we want to make certain
that everyone understands that there is no warranty for this free
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want its recipients to know that what they have is not the original, so
that any problems introduced by others will not reflect on the original
authors' reputations.
Finally, any free program is threatened constantly by software
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program will individually obtain patent licenses, in effect making the
program proprietary. To prevent this, we have made it clear that any
patent must be licensed for everyone's free use or not licensed at all.
The precise terms and conditions for copying, distribution and
modification follow.
GNU GENERAL PUBLIC LICENSE
TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
0. This License applies to any program or other work which contains
a notice placed by the copyright holder saying it may be distributed
under the terms of this General Public License. The "Program", below,
refers to any such program or work, and a "work based on the Program"
means either the Program or any derivative work under copyright law:
that is to say, a work containing the Program or a portion of it,
either verbatim or with modifications and/or translated into another
language. (Hereinafter, translation is included without limitation in
the term "modification".) Each licensee is addressed as "you".
Activities other than copying, distribution and modification are not
covered by this License; they are outside its scope. The act of
running the Program is not restricted, and the output from the Program
is covered only if its contents constitute a work based on the
Program (independent of having been made by running the Program).
Whether that is true depends on what the Program does.
1. You may copy and distribute verbatim copies of the Program's
source code as you receive it, in any medium, provided that you
conspicuously and appropriately publish on each copy an appropriate
copyright notice and disclaimer of warranty; keep intact all the
notices that refer to this License and to the absence of any warranty;
and give any other recipients of the Program a copy of this License
along with the Program.
You may charge a fee for the physical act of transferring a copy, and
you may at your option offer warranty protection in exchange for a fee.
2. You may modify your copy or copies of the Program or any portion
of it, thus forming a work based on the Program, and copy and
distribute such modifications or work under the terms of Section 1
above, provided that you also meet all of these conditions:
a) You must cause the modified files to carry prominent notices
stating that you changed the files and the date of any change.
b) You must cause any work that you distribute or publish, that in
whole or in part contains or is derived from the Program or any
part thereof, to be licensed as a whole at no charge to all third
parties under the terms of this License.
c) If the modified program normally reads commands interactively
when run, you must cause it, when started running for such
interactive use in the most ordinary way, to print or display an
announcement including an appropriate copyright notice and a
notice that there is no warranty (or else, saying that you provide
a warranty) and that users may redistribute the program under
these conditions, and telling the user how to view a copy of this
License. (Exception: if the Program itself is interactive but
does not normally print such an announcement, your work based on
the Program is not required to print an announcement.)
These requirements apply to the modified work as a whole. If
identifiable sections of that work are not derived from the Program,
and can be reasonably considered independent and separate works in
themselves, then this License, and its terms, do not apply to those
sections when you distribute them as separate works. But when you
distribute the same sections as part of a whole which is a work based
on the Program, the distribution of the whole must be on the terms of
this License, whose permissions for other licensees extend to the
entire whole, and thus to each and every part regardless of who wrote it.
Thus, it is not the intent of this section to claim rights or contest
your rights to work written entirely by you; rather, the intent is to
exercise the right to control the distribution of derivative or
collective works based on the Program.
In addition, mere aggregation of another work not based on the Program
with the Program (or with a work based on the Program) on a volume of
a storage or distribution medium does not bring the other work under
the scope of this License.
3. You may copy and distribute the Program (or a work based on it,
under Section 2) in object code or executable form under the terms of
Sections 1 and 2 above provided that you also do one of the following:
a) Accompany it with the complete corresponding machine-readable
source code, which must be distributed under the terms of Sections
1 and 2 above on a medium customarily used for software interchange; or,
b) Accompany it with a written offer, valid for at least three
years, to give any third party, for a charge no more than your
cost of physically performing source distribution, a complete
machine-readable copy of the corresponding source code, to be
distributed under the terms of Sections 1 and 2 above on a medium
customarily used for software interchange; or,
c) Accompany it with the information you received as to the offer
to distribute corresponding source code. (This alternative is
allowed only for noncommercial distribution and only if you
received the program in object code or executable form with such
an offer, in accord with Subsection b above.)
The source code for a work means the preferred form of the work for
making modifications to it. For an executable work, complete source
code means all the source code for all modules it contains, plus any
associated interface definition files, plus the scripts used to
control compilation and installation of the executable. However, as a
special exception, the source code distributed need not include
anything that is normally distributed (in either source or binary
form) with the major components (compiler, kernel, and so on) of the
operating system on which the executable runs, unless that component
itself accompanies the executable.
If distribution of executable or object code is made by offering
access to copy from a designated place, then offering equivalent
access to copy the source code from the same place counts as
distribution of the source code, even though third parties are not
compelled to copy the source along with the object code.
4. You may not copy, modify, sub-license, or distribute the Program
except as expressly provided under this License. Any attempt
otherwise to copy, modify, sub-license or distribute the Program is
void, and will automatically terminate your rights under this License.
However, parties who have received copies, or rights, from you under
this License will not have their licenses terminated so long as such
parties remain in full compliance.
5. You are not required to accept this License, since you have not
signed it. However, nothing else grants you permission to modify or
distribute the Program or its derivative works. These actions are
prohibited by law if you do not accept this License. Therefore, by
modifying or distributing the Program (or any work based on the
Program), you indicate your acceptance of this License to do so, and
all its terms and conditions for copying, distributing or modifying
the Program or works based on it.
6. Each time you redistribute the Program (or any work based on the
Program), the recipient automatically receives a license from the
original licensor to copy, distribute or modify the Program subject to
these terms and conditions. You may not impose any further
restrictions on the recipients' exercise of the rights granted herein.
You are not responsible for enforcing compliance by third parties to
this License.
7. If, as a consequence of a court judgment or allegation of patent
infringement or for any other reason (not limited to patent issues),
conditions are imposed on you (whether by court order, agreement or
otherwise) that contradict the conditions of this License, they do not
excuse you from the conditions of this License. If you cannot
distribute so as to satisfy simultaneously your obligations under this
License and any other pertinent obligations, then as a consequence you
may not distribute the Program at all. For example, if a patent
license would not permit royalty-free redistribution of the Program by
all those who receive copies directly or indirectly through you, then
the only way you could satisfy both it and this License would be to
refrain entirely from distribution of the Program.
If any portion of this section is held invalid or unenforceable under
any particular circumstance, the balance of the section is intended to
apply and the section as a whole is intended to apply in other
circumstances.
It is not the purpose of this section to induce you to infringe any
patents or other property right claims or to contest validity of any
such claims; this section has the sole purpose of protecting the
integrity of the free software distribution system, which is
implemented by public license practices. Many people have made
generous contributions to the wide range of software distributed
through that system in reliance on consistent application of that
system; it is up to the author/donor to decide if he or she is willing
to distribute software through any other system and a licensee cannot
impose that choice.
This section is intended to make thoroughly clear what is believed to
be a consequence of the rest of this License.
8. If the distribution and/or use of the Program is restricted in
certain countries either by patents or by copyrighted interfaces, the
original copyright holder who places the Program under this License
may add an explicit geographical distribution limitation excluding
those countries, so that distribution is permitted only in or among
countries not thus excluded. In such case, this License incorporates
the limitation as if written in the body of this License.
9. The Free Software Foundation may publish revised and/or new versions
of the General Public License from time to time. Such new versions will
be similar in spirit to the present version, but may differ in detail to
address new problems or concerns.
Each version is given a distinguishing version number. If the Program
specifies a version number of this License which applies to it and "any
later version", you have the option of following the terms and conditions
either of that version or of any later version published by the Free
Software Foundation. If the Program does not specify a version number of
this License, you may choose any version ever published by the Free Software
Foundation.
10. If you wish to incorporate parts of the Program into other free
programs whose distribution conditions are different, write to the author
to ask for permission. For software which is copyrighted by the Free
Software Foundation, write to the Free Software Foundation; we sometimes
make exceptions for this. Our decision will be guided by the two goals
of preserving the free status of all derivatives of our free software and
of promoting the sharing and reuse of software generally.
NO WARRANTY
11. BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY
FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN
OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES
PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED
OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS
TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU. SHOULD THE
PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING,
REPAIR OR CORRECTION.
12. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR
REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES,
INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING
OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED
TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY
YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER
PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE
POSSIBILITY OF SUCH DAMAGES.
END OF TERMS AND CONDITIONS
How to Apply These Terms to Your New Programs
If you develop a new program, and you want it to be of the greatest
possible use to the public, the best way to achieve this is to make it
free software which everyone can redistribute and change under these terms.
To do so, attach the following notices to the program. It is safest
to attach them to the start of each source file to most effectively
convey the exclusion of warranty; and each file should have at least
the "copyright" line and a pointer to where the full notice is found.
Copyright (C)
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
Also add information on how to contact you by electronic and paper mail.
If the program is interactive, make it output a short notice like this
when it starts in an interactive mode:
Gnomovision version 69, Copyright (C) year name of author
Gnomovision comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
This is free software, and you are welcome to redistribute it
under certain conditions; type `show c' for details.
The hypothetical commands `show w' and `show c' should show the appropriate
parts of the General Public License. Of course, the commands you use may
be called something other than `show w' and `show c'; they could even be
mouse-clicks or menu items--whatever suits your program.
You should also get your employer (if you work as a programmer) or your
school, if any, to sign a "copyright disclaimer" for the program, if
necessary. Here is a sample; alter the names:
Yoyodyne, Inc., hereby disclaims all copyright interest in the program
`Gnomovision' (which makes passes at compilers) written by James Hacker.
, 1 April 1989
Ty Coon, President of Vice
This General Public License does not permit incorporating your program into
proprietary programs. If your program is a subroutine library, you may
consider it more useful to permit linking proprietary applications with the
library. If this is what you want to do, use the GNU Library General
Public License instead of this License.
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