README

Directory Structure

The code is contained in the src folder.

1. tree_linkable contains:

   1. platform.py: Contains the class capturing the platform side of the source-tracking scheme. It also contains a main function that allocates connections to each user and another function for handling their interaction.

   2. user.py: Contains the class capturing the user side of the source-tracking scheme.

   3. utils.py: Contains the helper functions for source tracking.

   4. message_format.md: Contains all the message types that are passed between platform and user sides of the source-tracking scheme.

   5. test_protocol.py: Contains tests for platform and user classes.

   6. platform_pub_key.pem: Contains the public key of the current instance of platform.

2. axochat.py: Contains functions for sending and receiving messages among users utilizing the ratchet encryption. The user part of the source-tracking scheme is used here.

3. <*>.pkl: Auxiliary file for persisting fds across chat sessions.

4. <*>.db: Auxiliary file for persisting chat messages across sessions.

Usage

Initially, a platform instance needs to be setup followed the server side of the messaging pair and then the client side of the messaging pair.

• To start platform instance:

  1. Start a terminal.
  2. cd into the tree-linkable folder inside the src folder.
  3. Run: python platform.py -p <port-number>
     1. platform listens at the given port number.

• For setting up messaging pair (a, b):

  1. Start 2 terminals.

  2. In the first terminal (setting up server side (a) of ratchet scheme):

     1. cd into src folder.
     2. python axochat.py -s
     3. The following choice must be entered:
        1. "Enter your nick: " any string as a nickname of a.
        2. "Enter the nick of the other party: " nickname of b.
        3. "Enter the platform IP address: " (leave as blank and press enter if platform is on the same system).
        4. "Enter the platform port: " port number of platform instance.
        5. "TCP port (1 for random choice, 50000 is default): " The port on which a will listen to for b.

  3. In the second terminal (setting up client side of ratchet scheme):

     1. cd into src folder.
     2. python axochat.py -c
     3. Enter the appropriate choices as given for server side. For other choices:
        1. "Enter a 's ratchet key: " copy and paste the ratchet key shown in first terminal.
        2. "Enter the other client's ip address: " ip-address of server a (leave as blank and press enter if server is on the same system).
        3. "Enter the other client's port number: " Port number on which a is listening.

Sending a Message

message (press enter)

Forwarding a Message.

Fwd: <Username>:<msgid> (press enter)

Reporting a message.

Report: <Username>:<msgid> (press enter)