HPAC

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  *   *  *      *   *  *****  *     *  multi system archiver

This is the README for the Atari version of HPACK.

0. General
----------

This version of HPACK is complete, just about every and all feauture
should behave just like it does on all the other systems HPACK runs
on. That means that the original docs for HPACK supplied in this
distribution are valid and SHOULD be read.

This README just mentions the few details that differ from other
HPACK versions and gives some hints on how to use features that may
seem "esoteric" to a standard Atari user (i.e. someone that doesn't
know the UNIX operating system).

1. Why using HPACK?
-------------------

There are a bunch of archivers available for the Atari, so there may
arise the question of why we need an other one.

Well, I don't see HPACK as a direct opponent to archivers as ZIP or
LHarc, at least not on the Atari. I am aware that many users will find 
the speed of HPACK annoying.

But there are still some very good reasons to use HPACK. The following
list shows some of them.

  - HPACK is available for virtually every system of some importance,
    and all versions are REALLY compatible.
  - HPACK uses powerful unix-style wildcard matching.
  - HPACK allows large archives to be split over several disks.
  - HPACK uses powerful public-key encryption ("military grade")
  - HPACK allows archives to be secured with a "fingerprint" that
    ensures that an archive is not tampered with.
  - HPACK offers "unified" compression.

The following chapters give some hints on how to exploit these
advantages.

2. Other versions
-----------------

HPACK is available for nearly all systems of a minimum significance.
Unlike with many other archivers, all HPACK versions should behave
just the same - it doesn't make a difference if you use HPACK on
an Atari or a Sun Unix box. It is also no problem to archive the
files on that Sun box and then extract them on your Atari again.
I have seen HPACK binaries for DOS and Mac on the FTP server
src.doc.ic.ac.uk for example.

3. Wildcard matching
--------------------

HPACK uses unix-style wildcard matching. You probabely know the
significance of the characters * and ? in a filename. * stands
for a whole sequence of characters, while ? replaces one character.
HPACK also introduces other wildcards like []. To learn more about
them, refer to the full documentation.

A fact that may bewilder Atari users at first is that HPACK uses /
as directory delimiter and not \ as it is normal on Ataris.
This means you must use "folder/file" instead of "folder\file".
A second difference is that "*.*" doesn't match ALL the files,
but only files containing a dot. If you want all files, use "*"
instead. So, "folder\files\*.*" will get "folder/files/*".

After you got used to this new style file matching, you'll certainly
discover that it is much more flexible and well worth to learn.

4. Multi volume archives
------------------------

HPACK allows large archives to be split in multiple parts if they
don't fit onto your floppy disk (or removable HD media or whatever).
The parts will be fitted together again when you extract the archive.
What makes HPACK interesting, is that this works on all systems
HPACK runs on - that means you can transfer a 10MB file from a Mac
to your Atari by archiving it as a multi volume archive on your
Mac and then extracting it on the Atari - even if you have only
floppy disks for transfer.
If you think HPACK is too slow or if you want to transfer large,
already compressed picture files, try to use HPACK with disabled
compression. HPACK will split the file at lightning speed and
the archive is protected with a CRC checksum all the same, ensuring
that everything will be fitted together nicely again.
This is my way to transfer large files between different computer
systems.

5. Public key encryption
------------------------

Public key encryption (called PKE from here on) is a very powerful
way to protect your data from being abused. HPACK uses the same
algorithms as the well-known PGP to protect your data. In fact,
HPACK communicates with PGP perfectly.
To use PKE on your Atari you'll have to get a copy of PGP first.
At time of this writing, PGP 2.3a is current for Ataris. It can
be found on the FTP server "ftp.tu-clausthal.de" for example.
Now generate your public key/secret key pair with PGP. Refer to the
PGP documentation on how to do so. Note that the passphrase for your
secret key must be at least 8 characters long, otherwise HPACK won't
accept it (while PGP does).
The secret key needs conversion to use it with HPACK. For this,
a little program called KEYCVT is supplied with HPACK.
Start KEYCVT with "YourPath\SECRING.PGP YourPath\SECRING.PGP" as
parameters. I have encountered some problems when using KEYCVT
directly after PGP, my machine hangs after KEYCVT has finished.
This does not occur when I do a reboot after I used PGP. The whole
thing is a mystery to me, I cannot say what program is guilty of
that. The conversion will be completed correctly in any case. If
you need to reboot after KEYCVT, sorry for the inconvenience. By
far the biggest part of the users only use KEYCVT once anyway.
Now copy PUBRING.PGP, SECRING.PGP and RANDSEED.BIN from the PGP
directory to the HPACK directory.
Then rename RANDSEED.BIN to HPACKSEED.BIN.
That's all for the setup. You can now add new public keys to your
PUBRING using PGP, to do PKE with a public key from someone called
"Joe", do "HPACK a -cpaJoe archive file".
The security of such archives is very high, in fact it is "state-
of-the-art" and "military grade". Learn more about this in the
extended HPACK documentation supplied.

6. Data authenticity
--------------------

Data authenticity (DA) ensures that the receiver of your archive
can be sure that no third person played with it. For this, the
person you want to send the archive to first needs your public key.
You then create the archive with "HPACK -lJack archive file" if
Jack happens to be your name.
Note that you need to do the whole setup as described in the chapter
above, i.e. generate your public/secret key and so on.

7. Unified compression
----------------------

HPACK has a mode that uses compression buffers of files already
compressed for the following files. If you compress many files of
very similar structure (i.e. 20 text files or 15 C source codes),
you should try to do so with the "-u" switch given. This may yield
to spectacularily shorter archives in such cases.
Note that if the files differ very much, compressing the files
with unified compression turned on may result in a longer archive.

8. Atari specific stuff
-----------------------

I have added an option to the Atari version that forces HPACK to
wait for a keypress before quitting. Use this if you can't read
HPACK's screen output because the desktop is redrawn everytime
HPACK has finished its work.
The option for this is "+hold".

So, use "HPACK v +hold archive" to view a listing of the files in
an archive for example.

The Atari version comes in two flavours: If you have a TT, Falcon
or an ST you upgraded to a 68030 CPU, use HPACK030.TTP.
If you have a standard ST/STE/Mega ST/Mega STE, use HPACK.TTP.

9. Distribution
---------------

HPACK may only be distributed as a complete package, containing
all the following files:

  HPACK.TTP         -- The executable for STs
  HPACK030.TTP      -- The executable for TTs and Falcons
  KEYCVT.TTP        -- The key converter
  LANGUAGE.DAT      -- The language file
  MYKEY.ASC         -- A file containing my public key
  DOCS\HPACK.DOC    -- The HPACK documentation
  DOCS\HPACKEXT.DOC -- The extended HPACK documentation
  DOCS\README.1ST   -- The original HPACK readme
  DOCS\REGISTER.DOC -- The registration form

10. Disclaimer
--------------

HPACK comes with absolutely no warranty of any kind, expressed
or implied. Use HPACK only at your own risk. Neither the author
of this Atari port (Martin Braschler) nor the author of the
original HPACK version (Peter Gutmann) will accept responsability
for any damages or unforseen consequences of the usage of HPACK.

11. Credits
-----------

HPACK is written by Peter Gutmann (pgut1@cs.aukuni.ac.nz)
- if you use his great program a lot, then think of him. HPACK is
  Shareware, but you are not forced to register - a very nice move
  of him. If you use HPACK regularily, however, you should really
  consider to send him some money. You'll find the necessary
  information in REGISTER.DOC.

This Atari port was done by Martin Braschler. My thanks go to Peter,
who helped me a lot. And apart from that, he's just a cool guy.

I want to thank Manfred Becker, Matthias Rauhut and Dirk Allard
for testing the program.

12. Closing
-----------

You best contact me by email if that is possible for you. In the past,
some mails have been lost. I hope this does not happen again. But
if you didn't here anything from me within a week, maybe just try
to send a second mail. I try to reply to all mails I get.

Send them to: mbraschl@iiic.ethz.ch

If you don't have access to email, you can try to contact me via
regular mail. This is of course much slower. Please include a SAE
and enough postage, otherwise I won't reply. I hope you understand
this.

Send your letters to:
Martin Braschler
Brunngasse 16
CH-4124 Schoenenbuch
Switzerland

Have fun with HPACK!

All typos (c) 1994 Martin Braschler.


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