keygentoolshed/keyGen/encryptandecrypt/ciphers/caesarciphergenerator.js

Key generation utilities for cryptographic operations. QUANTUM ENCRYPTION FOLDER UPDATE!!! See its folder for all <3

// CAESAR CIPHER TIME :sob:

import yargs from 'yargs/yargs';
import { hideBin } from 'yargs/helpers';

function caesarCipher(message, shift, encrypt = true) {
  const result = [];
  const adjustedShift = encrypt ? shift : -shift;

  for (let char of message) {
      if (char.match(/[a-z]/i)) { // Check if the character is a letter
          const code = char.charCodeAt(0);
          const base = code >= 65 && code <= 90 ? 65 : 97; // Uppercase or lowercase
          const newChar = String.fromCharCode(((code - base + adjustedShift + 26) % 26) + base);
          result.push(newChar);
      } else {
          result.push(char); // Non-letter characters are added unchanged
      }
  }

  return result.join('');
}

const argv = yargs(hideBin(process.argv))
    .option('message', {
        alias: 'm',
        description: 'The message to encrypt or decrypt',
        type: 'string',
        demandOption: true
    })
    .option('shift', {
        alias: 's',
        description: 'The number of positions to shift the letters',
        type: 'number',
        demandOption: true
    })
    .option('encrypt', {
        alias: 'e',
        description: 'Set to true to encrypt, false to decrypt',
        type: 'boolean',
        default: true
    })
    .help()
    .argv;

    const result = caesarCipher(argv.message, argv.shift, argv.encrypt);
    console.log('Result:', result);