Byzantine problem solution for reliable communication and registers.

This application was built to experiment with the Byzantine crash-arbitrary problem.
The first part of the project was developed to be able to produce a public announcement without message encryption and be able to tell(on both the server and the client side) if the message was tampered with and ensuring non-repudiation. This was done using message signatures and a combination of message uuids.
A “hacker” can be placed in the middle to simulate a man-in-the-middle attack over the message(replay, tampering, etc) and the idea is that both the server and the client realize.

The second part of the project was developed to practice the use of 1-N Byzantine atomic registers and N-N Byzantine Regular Registers. A Byzantine Reliable Broadcast was implemented for this, in which all parts of the communication ensure that the message received was not tampered with. The Atomic Register was not finished.

Requirements

• Java 11
• Maven

Run

0. Keys path

Determine a local path where to save the server keys.
Ex: /local/path/to/save/keys

1. Build

cd local/path/to/Dependable-Public-Announcement-Server 
mvn clean install

2. Generate servers keystore

We generate each server's keys by:

1. Creating a folder were we place the keystore for all servers
2. Creating a key for each one by passing the folder path and the number of servers to our bash helper

mkdir -p /local/path/to/save/keys
sh serverKeysGenerator.sh /local/path/to/save/keys/server_keystore.p12 numberOfServers pass1234

3. Start the server

We now use a client_config.txt file to pass all the required parameters to the client (servers keystore, keystore password, alias, ports, etc).
Edit it to suit your needs, you can find an example in the src of the entire project.
Pass the path where the client_config.txt is located, the server number (ex: 1) and the port.

java -jar server/target/server-1.0-jar-with-dependencies.jar path/to/Dependable-Public-Announcement-Server/client_config.txt 1 8001

4. Start the client

The client will generate its own keypair by default, therefore a "new" client is generated on every run of the following jar. If you intend on using the same client more than once, please see section 4.2.

4.1 New client

The client_config.txt is the only parameter passed to the client.
By default the client generates a new pair of symmetric keys on startup.

java -jar server/target/server-1.0-jar-with-dependencies.jar /path/to/Dependable-Public-Announcement-Server/client_config.txt

4.2 Reuse the client's key

You can reuse a previous keypair by passing it as an argument on startup.

• Generate the client's key and save it in a keystore

mkdir -p /local/path/to/save/keys
cd /local/path/to/save/keys
keytool -genkeypair -alias clientKeyPair -keyalg RSA -keysize 2048 \
  -dname "CN=twitter" -validity 365 -storetype PKCS12 \
  -keystore client_keystore.p12 -storepass pass1234

• Move to the source code directory

cd local/path/to/Dependable-Public-Announcement-Server 

• Edit the client_config.txt file and remove the # to uncomment the needed parameters, replace the values with the ones you just used to create the client's key
• Run the client

java -jar server/target/server-1.0-jar-with-dependencies.jar /Users/pilo/development/ist/hds/Dependable-Public-Announcement-Server/client_config.txt

Run a hacker

To simulate a hacker you can start a proxy server that can read, drop, edit and duplicate the messages sent between the server and the client:

1. Start the server on port X
2. Start the hacker on port Y
3. Start the client and tell him the server is listening on port Y

Start the hacker

You could use the hacker to simulate a server's presence.
Pass the port where the hacker will start, the ip and the port the server is listening to.

java -jar hacker/target/hacker-1.0-jar-with-dependencies.jar 8001 127.0.0.1 8000

Run Maven tests

This runs simple tests we use to develop. For full testing of the server play around with the client.
These tests are used to check that the server returns correct or error messages when required.

mvn test