home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
Gold Fish 2
/
goldfish_vol2_cd1.bin
/
files
/
comm
/
fido
/
spot
/
rexx
/
pgp
/
autoen-decrypt.doc
< prev
next >
Wrap
Text File
|
1994-08-11
|
7KB
|
166 lines
First of all. I'm not that good in writing docs and this is a lousy excuse
for one. Hopefully everything is a bit understandable, else ask in the SPOT
area.
What is this?
--------------
With the help of these scripts you can easely encrypt ALL your net- and
e-mails. These scripts are completly transparant. You can still do a file-
attach, set the kill/sent flag etc. The only difference will be that the
contents (and subject) of the msg is encrypted.
It is possible to always encrypt mail to certain people or to never encrypt
mail to certain people. When you have the key of someone and you have stated
neither then the script will ask if the message should be encrypted.
Recieveing encrypted messages are always decrypted, but if you haven't got the
senders key then PGP will complain that it is not able to check if this
message is really from that person.
These Arexx scripts are to be used together with the Spot mail reader.
You need at least Spot v1.3 since I'm using some new commands which are only
available from v1.3 and up.
Installation
-------------
PGP:
I will also explain how to install PGP since you need it for this script.
I used for this installation PGP 2.3a.2.
Decrunch the pgp archive.
Do a 'makedir dh0:s/pgp'.
Do a 'copy bin/PGP.config bin/pgp.hlp bin/language.txt to dh0:s/pgp/'
Do a 'copy bin/PGP to C:'
Put the following line in s:user-startup : 'SetEnv PGPPATH "dh0:s/pgp"'
Reset the computer and PGP is installed. Now you have to generate your keypair.
Type in the shell 'pgp -kg'.
Choose a keysize (best to take a 1024 bits size).
Now you have to type your user ID. For instance, my name is 'Wim Van Goethem'
and my fidonet address is '2:292/603.6'. My user ID would then become:
Wim Van Goethem <2:292/603.6>
It is important that your user ID has this form. The scripts won't be able to
find your key if you do it any other way.
The passphrase is very important. Do not use 1 or 2 words here, but use a
famous quote (so you will remember it). Then, make a deliberate writing error,
making it even more difficult for someone to guess your passphrase. Use also
punctuation marks. This will make it very difficult to guess your passphrase.
For instance: 'Captain, I protest. I am NOT a merrie man! - Worf'
Now the tedious part comes. You have to type random characters with random
timeintervals. This can take a long time on a standart A500 (so don't give up).
After a while, your keys will be ready.
If you want to recieve encrypted mail from someone, he has to have your public
key. To extract your public key you have to type: 'pgp -kxa 2:292/603.6 ram:x'.
You can now file attach your key (ram:x.asc), or include it in a message that
you will send him (the [a]scii option was meant for this).
Before your friend can encrypt messages for you, he has to add your key to his
public keyring. He has to type: 'pgp -ka x.asc'. Check if the key was
succesfully added. To do this, you have to type 'pgp -kv' and the holder's name
of the key you just added should be printed.
Now your friend can encrypt a message for you with:
'pgp -esa ram:message 2:292/603.6'
Naturally, he can also use my scripts :-).
Offcourse, you should have his key, so you can check the signature and be
certain that the message comes from him.
AutoEncypt.spot:
Copy the script to 'rexx:'.
Modify the '_Export.spot' file (Normally located in rexx:). You should call
AutoEncrypt.spot just before the 'export' command. See the included example.
Make a file called 'mail:Spot.encryption'. Inside you will have to specify if
the messages addressed to that person will be encrypted or not. See include
example.
AutoDecrypt.spot:
Copy the script to 'rexx:".
Modify the '_Import.spot' file (Normally located in rexx:). You should call
AutoDecrypt.spot just after the 'import' command. See the included example.
Usage
------
You need to include a unique identification in the encryptionlist. For
people on InterNet is this the InterNet address (e.g. wim@augfl.be), for
people on FidoNet the fidonetaddress (e.g. 2:292/603.6). Make sure you have
their keys and that this unique ID is in it (use the 'name <address>' format).
After this identification you can place some comments (his/her name for
instance). Everything placed after ';' is regarded as a comment.
If you have someone's key and he is not in the encryption list then the
script will ask you if you want to encrypt the message to this person.
Because of this, it is beter that you export the messages when you are
quiting Spot. You could use a cron type program, but you have to be sure that
no messages have to be encrypted or Spot will be locked up by the script. If
you still want to use a cron then you can also use PGPPASS. If you use PGP
ONLY for e-mail, then you could put in your user-startup the following:
setenv PGPPASS "your passphrase".
Since you use it only for e-mail and the msg's are still in your messagebase,
no sincere securityleak is possible. After all, they have to get in your house
to get your passphrase and you would problably notice this:-). They would
then also have the decrypted message's. If needed, you could revoke the old
key and generate a new keypair. You have to be carefull with your friends
ofcourse. They could easely find out your passphrase by reading the env
variable. So don't leave your friends alone with your computer if you
decide to do this :-).
You have to place your netmailareas on top of the arealist. The scripts will
stop en/decrypting message's if it encounters an area other than netmail.
You can specify if the passphrase should be erased when the scripts exit. To
do so you have to make the DelPGPPASS variable 1 (you have to modify the
scripts). If you make DelPGPPASS=0 then the scripts will erase PGPPASS.
However, if there was already a PGPPASS variable when the scripts started,
the PGPASS will never be erased. This is done so you can use cron-type
programs.
There is also a PGPPath variable used in the scripts. As long as PGP sits in
'C:' you won't have to use this, but if PGP sits not in your searchpath you
will have to modify it so that the script can call PGP.
These 2 auto- scripts are compatible with the two included en/decrypt.spot
scripts.
DISCLAIMER
I have tested these scripts as good as I could and I am using them daily but
if you use these scripts, you are on your own. I can not be held responsible
for loss of mail or other damage resulting, direct or indirect, from the use
or abuse of these scripts.
Remember!
If anything can go wrong, it will. Murphy
Send bug reports, comments, flames to:
Wim Van Goethem
InterNet: wim@augfl.be
FidoNet : 2:292/603.6
I prefer encrypted mail :-).