README.md

Cripto CLI

• Summary
• Run from sources
• Features
• Sending files
  • Elgamal cipher
  • RSA cipher
  • Shamir cipher
• Digital signature
  • RSA based
• Implementation

Summary

This educational project provides command line utilities implemented with basic cryptography algorithms

Run from sources

go run */**.go 

Features

*Each command supports -h/--help

Sending files

You can send files using several encryption algorithms

Elgamal cipher

# this starts receiver server and saves public key to file
crypto elgamal-msg recv -P 30803 -G 2 --port 12346 

# this sends given file to server  
crypto elgamal-msg send --bob-pub bob_elgamal.key -P 30803 -G 2 localhost:12346 some-file.txt

RSA cipher

# this starts receiver server and saves public key to file
crypto rsa-msg recv -P 30803 -Q 1297 --port 12346

# this sends given file to server  
crypto rsa-msg send --bob-pub bob_rsa.key localhost:12346 some-file.txt

Shamir cipher

# this starts receiver server
crypto rsa-msg recv -P 30803 -Q 1297 --port 12346

# this sends given file to server  
crypto rsa-msg send --bob-pub bob_rsa.key localhost:12346 some-file.txt

Digital signature

RSA based

# generate public and secret keys. P and Q are large prime numbers
crypto rsa-ds key-gen -P 30803 -Q 1297 

# cerate signature file for given message file
crypto rsa-ds sign -s rsa.key some-file.txt

# validate signature for file with public key
crypto rsa-ds validate -p rsa_pub.key -s signature-file some-file.txt

Implementation

Despite of the fact this application is not really complex, I tried to support ideas of clean architecture and explicitly manage dependencies between codebase parts.

Wherever as possible I use interfaces and functional arguments rather than theirs implementations to separate responsibilities.

Also such approach allows to write highly testable code.

Project structure is pretty standart:
`cmd` - deals with conponents of user interface such as flag         parsing, command structure specification etc. 
`internal/core` - contains pure math and algorithms implementation
`internal/app` - use cases and infrastrucure interactions, e.g. implementations of TCP-based file transfer protocols