pySHA

Author: Dominick Hing, dominick.hing1024@gmail.com

This repository contains an implementation of the following functions: SHA-1, SHA-224, SHA-256, SHA-384, SHA-512, SHA-512/224, and SHA-512/256, along with a program that uses these implementations to hash various inputs.

Disclaimer: this repository is intended to demonstrate the SHA algorithms for educational purposes only. It is not intended for use in production deployments. For production deployments, use the built in hashlib library or the PyCryptodome library. The PyCryptodome library can be installed using pip install pycryptodome. Rather, these implementations are intended to serve as an educational resource to demonstrate how these functions work.

The repository comes with a main sha.py program which accepts inputs and returns the hash value. It also includes a file shatester.py which can be used to verify the accuracy of the provided implementations.

Files

This repository is structured such that all of the SHA algorithms can share as much functionality as possible. This is mainly done in hashframe.py and the individual algorithms are implemented in separate files under the pySHA directory. The main program to be run is sha.py and the testing program is shatester.py

• sha.py: the main program used to run the SHA implementations
• shatester.py: the testing program used to verify that the SHA implementations are correct
• pySHA: folder containing the SHA implementations
  • __init__.py: allows for simplified naming conventions by the importing python file
  • hashframe.py: provides a skeleton used by the individual hash functions that contains various shared functionality
  • sha1.py: implements that SHA-1 class
  • sha224.py: implements the SHA-224 class
  • sha256.py: implements the SHA-256 class
  • sha384.py: implements the SHA-384 class
  • sha512_224.py: implements the SHA-512/224 class
  • sha512_256.py: implements the SHA-512/256 class
  • sha512.py: implements the SHA-512 class

Functionality

To run the main SHA program, run python3 sha.py along with additional arguments

• -a or --algorithm: accepts values of 1, 224, 256, 384, 512, 512/224, 512/256
• -v or --verbosity: accepts an integer from 0 to 5, with 0 being the least verbose and 5 being the most verbose. Defaults to 0. The higher the verbosity, the more intermediate steps are displayed in the terminal.

Exactly one of the following must be provided:

• -t or --text: provide the text to be hashed directly through the command line
• -f or --file: provide a filename to be hashed directly through the command line. The file's contents will be hashed. This is equivalent to using the shasum command directly in the terminal with a file input.
• --test: hash the string abc

Examples:

• To hash the file index.html using SHA-256 with verbosity 2, run python3 sha.py -v 2 -a 256 --file index.html in the command line.
• To hash the string 'foo' using SHA-1 with verbosity 0, run python3 sha.py -a 1 --t foo

Testing

To run the testing suite, you must install PyCryptodome. The easiest way to do so is using pip: pip install pycryptodome. This is also provided in the requirements.txt file, so you may also use pip install -r requirements.txt

Then run python3 shatester.py. This will run the testing suite to verify that all SHA implementations are correct