written by Jens Heine 2005
<Deutsche Version> <English version>
The comboard is a chat and filesharing program for small usergroups. The development of the comboard was motivated by the lack of security in most chat networks (public central servers, no encryption, ...). While using the internet as a communication channel it should be clear that encrypting these connections is a must. The comboard uses state of the art cryptografic functions like RSA and SSL to guarantee the privacy of your communication.
If java is already installed on your system we can go on:
Windows
Create a new folder: c:\programs\comboard. Copy the comboardstarter program into the new folder and doubleklick on it. The comboardstarter program downloads the comboard.jar file and starts it. The comboardstarter later also checks for comboard updates and downloads them. Now you should make a link to the comboardstarter.jar file on your desktop.
You can also download the comboard directly and start it with a doubleklick.
Linux/Unix
Create a new folder in your home directory: /home/username/comboard and copy the comboardstarter there. Then start it with „java -jar comboardstarter.jar“.
You need Java installed in your system to be able to start the comboad or the comserver. You can download it here: http://java.sun.com/j2se/1.4.2/download.html and install it afterwards. The current version is J2SE v 1.4.2_08 SDK. To check which java version is installed/active in your system, you can type „java -version“ in a dos-box or under Linux in a shell. There are various java versions from different vendors. Try blackdown for example.
Comboard with Java 1.4 or 1.5 and IAIK
You also need a special library from IAIK. The comboard tries to install the file when it starts. I thank the Stiftung SIC/IAIK very much for making a free licence available. The IAIK library will be available in the evaluation version. It is only allowed to use the IAIK library with the Comboard.
USE THIS SOFTWARE ON YOUR OWN RISK !! THIS SOFTWARE MAY HARM CRYPTOGRAPHIC LAWS OF YOUR COUNTRY !! THE DEVELOPERS GIVE NO WARRANTY FOR THIS SOFTWARE. THE SOFTWARE INCLUDES NON FREE SOFTWARE FROM IAIK (cryptostuff comboard and comserver) READ THE USAGE RESTRICTIONS OF THESE VENDOR !! THIS SOFTWARE IS ONLY FOR PRIVATE USE !! FOR COMMERCIAL USE CONTACT THE AUTHORS !!!
If the iaik library can not be installed by the comboard, you have to go to this registration site to get a user and password by email. Then you can download the library iaik_jce_full.jar. Download it into your local java installation. The target folder is <JAVA_HOME>/jre/lib/ext. Windows users copy the file into something like „C:\Programs\Java\<version>...\jre\lib\ext“. Linux users copy the file to something like „/opt/blackdown-jdk-1.4.2.02/jre/lib/ext/“. This file provides the cryptografic functions for the comboard. If you have any problems downloading the file, please send me an email.
Comboard with Java 1.3
If you still use java 1.3 please read the following. Java 1.3 does not allow high encryption per default. To enable the high encryption which is needed for the comboard, you have to copy 2 policy files from sun into your local java installation. Download the files from here. You need the files "local_policy.jar" and "US_export_policy.jar". Copy the to "<JAVA_HOME_ORDNER>/jre/lib/security". You can save the old original policy files somewhere else.
Hint: If you use java 1.3 you do not need to download the iaik library.
The comboard stored all files in the folder from which it is started. The following files will be stored here:
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peter.key – Userkey (aka keyfile, private key), this file must be kept private. It is possible to secure this file with a password (login dialog). peter.certificate – User certificate, public key. This certificate file will be created when you create a new user account. comboard.conf – Configuration file. Here you can for example change the loglevel. peter.downloads – Cache file. Information of interrupted downloads will be stored here. peter.mail – Mail file. Your usermails will be stored here. randomseed – Cache file. A random seed will be saved in this file to speed up the start of the comboard. |
The communication is completely encrypted with state of the art algorithms (RSA/SSL). Chat communication runs un-enrypted through the comserver. It is theoretically readable by the comserver admin so make shure that no one untrusted hosts your comserver. Filetransfers can not be read by the comserver. Thy run directly between 2 users.
File transfers run in peer2peer mode. The traffic does not run through the comserver and does not stress the network segment of the server..
Encryption algorithms: RSA keys, SSL/TLS1 technique. Key size from 512 to 2048 bit possible.
Comserver autentication possible. If the comserver admin creates the user keys with the comserver, the user keys will be signed with the certificate from the comserver. With a so created user key the user can verify the comserver later. This prevents comserver spoofing. This practice is a bit complicated but for some situations the saved solution.
Private chats are extra encrypted with RSA. The encryption is done with the public key of each communication partner. This enshures that even the comserver provider will not be able to read these messages.
Commails can be encrypted with the public key of the receiver.