Intro to Software Systems Assignment 4

This repo is created for the assignment 4 of our course Introduction to Software Systems.

Deployed on heroku at https://shrouded-mountain-98925.herokuapp.com/

To run it locally

• Run git clone https://github.com/Ista2000/ISS-assign4.git to clone this repository.
• Run virtualenv env to create a virtual environment for the project.
• Run pip3 install -r requirements.txt to install all the dependencies.
• Run flask run to run the app in your localhost.
• Visit 127.0.0.1:5000 for the website.

API reference

• /api/generate
  • Arguments:
    • sz(Required): Size of the key
    • e(Optional): Set the e value, defaults to 0x1001
  • Returns n, e, p, q, d % (p-1), d % (q-1), coeff, d
• /api/encrypt
  • Arguments(All required):
    • message: The message to be encrypted
    • n: The public key
    • e: The exponent in the public key
  • Returns the encrypted message
• /api/decrypt
  • Arguments(All required):
    • crypto: The encrypted message
    • n: The private key
    • d: The d value in the private key
    • e: The exponent in the private key
    • p: The first prime in the private key
    • q: The second prime in the private key
  • Returns the decrypted message

Util functions

• The functions all use the rsa python library which can be installed using pip3 install rsa
• All the util functions are written in utils.py
  • generate(sz, e): returns n, e, p, q, d % (p-1), d % (q-1), coeff, d
  • encrypt(message, n, e): returns the encrypted message
  • decrypt(crypto, n, d, e, p, q): returns the decrypted message

Design patterns identified

• Factory pattern while initializing the database. An empty constructor is used to create an instant of the database object in the models.py file but the app context is added in app.py
• Singleton pattern while initializing the database. There cannot exist two different instants of the database object at some point of time, that is why a singleton pattern is alays used when initializing a database connection object

Continuous integration

• Implemented continuous integration using TravisCI. The .travis.yml file is the config file used.
• Unit test cases written in tests.py

Continuous Deployment

• A pipeline is set up in Heroku for continuous deployment. The link is given above. The Procfile file is the config file used.