Copyrights, patents and warrantiesRSE contains copyrighted software!
The design of RSE - The Reliable Security Environment - is Copyright ©
Ralf Senderek 2000. All rights reserved. These rights include but are not limited to any foreign language translation of this documentation or the copyrighted software, and all derivative works of both. All other parts of RSE which are not signed by the author - LINUX, SSH, PINE, and PGP - are subject to their authors copyrights, patents and regulations respectively and it is entirely to the user's duty to comply with any legal implication of this software. The author explicitly grants licence to anyone for non-commercial use of RSE. But to ensure the reliablity of the author's copyrighted software, changing the code and redistributing changed code is not permitted under any circumstances. The author assumes no liability for damages resulting from the use of this software, even if the damage results from defects in this software, and makes no representations concerning the merchantability of this software or its suitability for any specific purpose. It is provided "as is" without expressed or implied warranty of any kind. Because of the fact that certain actions may delete files or render them unrecoverable, the author assumes no responsibility for the loss or modification of any data. |
The main purpose of SECT which has determined its design is to provide a platform for establishing a secure contact to a remote computer system, using strong cryptography and therefore allows you to work on the remote and reliable system using a totally insecure network to establish the connection. SECT is the basis for using the RSE-disk as well, because if you do not have a reliable system on the net you can turn your local computer into a Reliable Security Environment by running the program "RSE start" on SECT or by configuring SECT to run RSE automatically.
After having checked the signature of the file RSE.dd.pgp you can build your initial RSE-disk from the file RSE.dd using UNIX or DOS.
UNIXPut a formatted 3½'' floppy into the first drive and use the following command:
dd if=RSE.dd of=/dev/fd0 bs=1k |
DOSYou can use dd.exe, a shareware programm made by Helmut Schellong. See the documentation.Put a formatted 3½'' floppy into the first drive and use the following command:
dd if=RSE.dd of=fd0:c80h2s18 bs=1k |
Because of the fact the fingerprint of your encrypted home will change each time it is encrypted again it is of no use to display it here. But the fingerprint of the filesystem (Blocks 200 - 1240) should only vary with new versions of RSE. But to rely on those fingerprints you have to check the integrity of the md5-binary with "checkSECT" first.Checking RSEs integrity ... Are you sure the RSE-disk is in the drive ? [yes/] : yes 66c618714f4011f2038ab1cef491d4f2 filesystem
The configuration "/RSE/rse/.RSEconfiguration" can contain the following entries:
The first 200 blocks of your RSE-disk are reserved to store your
homedirectory in a PGP-encrypted and compressed format. If you start
RSE for the first time you are prompted for the passphrase to
use for the protection of your homedirectory, which has set to
"rse" for obvious reasons and should be changed, while you stop RSE, when
you are asked to enter a passphrase to finally save your homedirectory
again. Please choose a secure passphrase. I have tried to
give some hints which may be useful to select a secure passphrase
you will find at the URL
https://senderek.com/security/secret-key.protection.html#passphrase.
Note, that while PGP-encryption and compression is used to store all the files in your homedirectory, you can possibly store up to 400 MByte data in your homedirectory. But as your mail is coming in this space might get too small, so you have to do some backup and saving with the tools described below to keep enough space in your homedirectory.
If you shut down RSE while using "RSE stop" or "save.RSE" and your homedirectory holds too big files to be saved to the RSE-disk, you will be warned, and exactly those files or directories will be saved on the RSE-disk which are listed in the file "/RSE/rse/.save" . Note, that this will overwrite the existing data on the RSE-disk. You should then backup all important data before you turn off the power, because everything will then be gone.
If you wish to have established a periodical query for new mail automatically you can store your mail-password in clear text in a file /RSE/rse/.mailsecret and getmail will then do its job quietly in intervals you can specify in the configuration file. All output from the mail server will be appended to a file /tmp/.maillog where you can scrutinize the progress of the queries which will be forgotten after rebooting the system.
Storing your mail-password in clear text is a risc, if someone is able to see your homedirectory while the system is running in RAM. But that one should only be you. The firewall should not permit remote connections to your local system, and your homedirectory will always be stored on the RSE-disk encrypted.
But if a file ".securemail" is present in the user's homedirectory, even if it is of zero bytes length, a menu will pop up and you can choose SIGNING and/or ENCRYPTION or you can SEARCH for public keys in your keyring with a single keystroke. PGP will then be used to perform signing and encryption and the result will be displayed in the mail client immediately. So PGP is transparently used as an appendix to the alternate editor of your mail client.
To get this being effective your configuration file for PINE called /RSE/rse/.pinerc contains the following entries:
editor=/RSE/securemail/securemail display-filters="-----BEGIN PGP" /RSE/securemail/checkmail _TMPFILE_Consequently every mail message you receive, which contains the string "-----BEGIN PGP" will be read using the program "checkmail", which runs PGP on the message and informs the user if the result contains a good signature or displays a warning.
Because of their filter-performance "securemail" and
"checkmail" can be used independently with any other
software which supports input and output filters.
"securemaileditor", a link to securemail can be
used as a stand alone editor with PGP-functionality as well to produce
and sign digital documents.
The file /RSE/rse/.securemail can contain the following two entries :
which determine the design of the user's menu. You always can add signing or encryption or you can decide to apply no change to the originally edited text at any time which gives you full flexibility while editing your outgoing mail.
- SIGN=always
- ENCRYPT=always
Saving Files Securely
Although files in your homedirectory will be saved to the RSE-disk every time
you shutdown RSE there are two programs "ssave" (secure-save)
and "sex (secure-extraction)" which will help you to backup
your data during every-day use of RSE. If you receive lots of data with
your mail you will need a backup-tool quickly. Both programs are using
archives to save the files, so that you will have a single archive on
another medium for a backup. If you like to save files individually
you can use the tools "scopy" (secure-copy) and
"icopy" (insecure-copy) as user "root".
When invoked without any parameters, ssave will automatically save all
files listed in the file /RSE/rse/.save
to the floppy in the boot drive. Please use one or more special
SECURE-DATA disks for the backup and avoid to overwrite your RSE-disk.
If you use the option "-append" ssave will read an archive from a
disk, decrypt it using PGP and the content will be stored on a RAMDISK
mounted on /backup. If your appended data will lead to no more than
1300 kByte the archive will be stored to (another) disk after being
encrypted with PGP again.
Please bear in mind that you always will have only one archive on a single disk which is called "data.tar.pgp" and that you will replace the existing data unless you are using the option "-append" respectively.
If you like to have your data-archive on a floppy with a DOS-filesystem instead of using the disk as a tar-archive you can specify this in the main configuration file with the entry DISK="dos".
The meaning of sex is to extract all the goodies from an archive
individually or when invoked without any parameters as listed in the
file /RSE/rse/.load in a bunch.
You can use sex with parameters to extract single files from an archive
if they are actually stored there, but you have to remember the passphrase
you have used with ssave.
The user "root" can use scopy to encrypt single files with PGP for storage
on any medium which is available including harddisk-partitions.
The devicefile to be used for storing the files can be specified using
"-destination /dev/sda1" for instance. Accordingly the option
"-source /dev/hdb4" specifies a partition to read files from this source
that will be stored in the working directory.
Without any files specified scopy will look for files on the medium and
missing a device file it will either try to access the medium which is
set as SECUREMEDIUM in the main configuration file or it will use the
boot floppy drive as a default. So you can use scopy to see the content
of your storage medium. All files will be PGP-encrypted individually
and are saved to the same medium.
But all files will be stored on the medium as clear text. There will be
no protection!
In case you decide to use the program "icopy" to write
clear text data to some device which only root can do you are warned
that there will be no protection for your files you save. Be cautious
while using this tool.
Securemail is designed to act as a transparent input/output
filter software which shows the use of PGP any time it is invoked. As
you can see the filtersoftware does never read passphrases, this job is
done by PGP entirely.
Programs to Use with RSE as Root
There are some programs designed for the use of the user "root" only.
scopy
usage : scopy [files]
usage : scopy [-destination [device]] [files]
usage : scopy [-source [device]] [files]
morepace
This program creates another RAMDISK of 4 MByte size which is added to the
filesystem as /A /B or /C.
extract.RSE
This program will be run from the script "RSE start" automatically
creating a RAMDISK mounted to /RSE which holds all of the RSE-software.
The user's homedirectory will be restored next , the mail software will
be prepared according to the user's configuration and finally getmail will
be started to fetch new mail. Normally this does not have to be done twice.
RSE stop
To shut down the Reliable Security Environment and to return to the state
of the original SECT-disk the user's homedirectory will be saved to the
RSE-disk and all changes RSE has done to the filesystem will be reverted.
save.RSE
During this process save.RSE is used to save all files in the user's
homedirectory to the RSE-disk. This will replace all existing data on the
RSE-disk.
Saving Files Insecurely
* without any encryption *
you can use "icopy" which can be used in exactly the
same way as "scopy". The Security of Your System
If you create new space in the filesystem this will also be a RAMDISK.
The integrity of your RSE-disk can be checked at any time with
checkRSE which will produce the md5-fingerprint of the
filesystem as stored on the disk.
There is also no device used for swapping, so that no part of the
memory can be found elsewhere. So your passphrase which unlocks your
secret-key will not be stored anywhere except the main memory of the system.
Filesystem 1024-blocks Used Available Capacity Mounted on
/dev/ram2 3963 2467 1496 62% /
/dev/ram3 3963 3206 553 85% /RSE
/dev/ram5 3963 13 3746 0% /A
As a matter of fact there are no daemons running in the background
which provide services to the net and there is not even a smail-daemon
running on RSE, because smail will be invoked on demand when outgoing mail
is sent. That will ensure that your system has minimal connectivity,
just sufficient to open a secure connection to one single system and
to transport your mail.
Credits
The Reliable Security Environment uses :
All rights are reserved to the authors of this famous software and everyone
who has contributed. I am glad that I could find such a professional
basis for the design of RSE. I thank you all very much.
Files
Copyright ©
Ralf Senderek 2000