WordCypt

Readme for WordCrypt v2.0 Copyright 1999 UK Adam Brinley Codd Introduction ============ WordCrypt is a program for people who have forgotton the password on their Psion Word files. This version asks for the first 9 letters of the document, and uses that to decrypt the document. Unlike the password, it is case sensitive, but you don't need to get it exactly right to decrypt the document, therefore you can guess it. It might be the title of the document for example. You must not use WordCrypt on someone else's documents unless they give you permission. Installing and Running ====================== Copy the WORDCYPT.OPA file into your APP directory (you may need to create one), then go the system screen. Position the cursor to the right of where you want the icon and press <PSION> and <I>. Choose WORDCYPT.OPA from the list. An icon will appear, similar to the Word icon, and underneath it will be a list of files in your WRD directory. Highlight one of them and press <ENTER>. Next, you will be asked to enter the first 9 letters of the document. It will then decrypt the first 500 letters, and will ask you if it is correct. If not, you may choose another 9 letters. When you get the right 9 letters, you can decrypt the entire document either into a plain text file (which takes quite a long time) or as a Word document, which means the formatting will be kept. Uninstalling ============ Position the cursor underneath the WordCrypt icon in the system screen, and press <PSION> and </>. Then delete the WORDCYPT.OPA file from your APP directory. Issues ====== Known problems and bugs: I don't know this for sure because I haven't tried it out, but I think if you have a paragraph longer than 16k (just over 16 thousand characters) and try to save it as a text file, WordCrypt will crash with an 'Overflow' error. To get around this, I recommend you save it as a Word file, and then from within Word save it as a text file. Also, sometimes it may say 'There is not enough space to store the file in memory'. Usually just quitting the program and trying again solves this problem. I don't know why it occurs though. Misc Information ================ Details on how this program works are available from my web site (see below). You must not use this program to see other people's word documents without their permission. WWW Site: http://w3.to/adamjbc E-Mail : adamjbc@hotmail.com If you want to see the source code to this program, don't bother RevTranning it because most of the variables are LOCAL so it will be hard to understand. E-mail me and I'll give you the source. History ======= Version 1.0 Initial release, fully working but very slow converting to plain text Version 1.1 Speeded up convertion to plain text after a lot of fiddling trying to get the buffer OS call to work :-) Version 2.0 Fixed the problem of it not working on files over about 20k by changing the variable the length of the data is to a long (rather than a short integer). It also meant I had to change a whole lot of other stuff which I hope made the program better and faster. Here's a brief description of what I did leading up to Version 1.0: I started by investigating the encryption commands built into the Psion. The password is used to produce a 16 bit encryption key, and then something is done to this key, and it is placed inside the word file. I couldn't work out how to get the original key from the one inside a word file, so I took a different approach. I realised that I could reverse the encryption process, and if I knew the original text, I could get the key, and use then to decrypt the rest of the document. I wrote a small program to test this theory, but I came accross a problem, but it was sloved easily. Next, I wrote a program which decrypted the text from a word file using the first 9 letters and then wrote it to a text file. However, the text in word files isn't stored as plain text, e.g. carrige returns are replaced with 0x00 and there are breakable and non breaking hyphens and spaces to deal with, so I changed the program to take the decrypted text, and convert it to normal ASCII as it wrote it to the file. Then, I added the option for saving it as a Word File which was very easy, compared to converting it to plain text, as I just inserted the decrypted data back into the document, and changed the flags within the document which say it's encrypted. Finally, I added a load of UI code to make it look nicer and easier to use, and added better error handling. I also spent quite a while making the icon, it's the normal Word icon, but with a padlock (taken from the password dialog box) instead of the fancy Q. If you can make a better icon, please do so and e-mail it to me. Future ====== In future versions, if there is demand, I will add the following features: o Better routine for guessing the first 9 letters (i.e. showing you which letters you got wrong) o Maybe automatic guessing of the first 9 letters If you can think of anything else, e-mail me.