Be sure to have OpenSSL library installed. If you run this project on Hopper, you don't need to install anything. !!! Tasks needed to complete:

• Go to common.cpp under the Common folder, write code in the encryptWithPSK() and decryptWithPSK() methods
• Go to main.cpp under the Client folder, complete all the parts marked with TODO
• Go to server.cpp under the Server folder, complete all the parts marked with TODO

*Notes:

• The encryptedwithPSK() and decryptWithPSK() methods are very similar with the encryptMessage() and decryptMessage()methods. The only difference is that those take the session key rather than the pre_shared key.
• Most of the TODO parts in main.cpp are the same as those in server.cpp. Pay attention to the variables' names!
• This is the source that you can use to complete the TODO tasks: https://wiki.openssl.org/index.php/Diffie_Hellman

To run the chat application:

1. In the project3_part1 directory, run the following commands:
   • mkdir build
   • cd build
   • cmake ..
   • make
2. Run the client and server (you can have multiple client instances):

• In the build directory, run the server by: (run the server first)
  • cd Server
  • ./server_executable
• Open another terminal, in the build directory, run the client by:
  • cd Client
  • ./client_executable

Testing: Check the following:

• Client's Public Key in the client = Decrypted Client's Public Key in the server (regardless of uppercase or lowercase)
• Server's Public Key = Decrypted Server's Public Key (regardless of uppercase or lowercase)
• Shared Secret in the client matches Shared Secret in the server After the session is made, then do the following:
• In the client terminal, type a message
• In the server terminal, an encrypted message and the message you just typed in the client terminal will show up If both messages match, then you do all the methods correctly