index.ts

import * as crypto from "crypto";
import * as readline from "readline";

const rl = readline.createInterface({
  input: process.stdin,
  output: process.stdout,
});

function generateKeys() {
  const { publicKey, privateKey } = crypto.generateKeyPairSync("rsa", {
    modulusLength: 2048,
    publicKeyEncoding: {
      type: "spki",
      format: "pem",
    },
    privateKeyEncoding: {
      type: "pkcs8",
      format: "pem",
    },
  });
  return { publicKey, privateKey };
}

function encryptMessage(publicKey: string, message: string): string {
  const encrypted = crypto.publicEncrypt(
    {
      key: publicKey,
      padding: crypto.constants.RSA_PKCS1_OAEP_PADDING,
      oaepHash: "sha256",
    },
    Buffer.from(message)
  );
  return encrypted.toString("base64");
}

function decryptMessage(privateKey: string, encryptedMessage: string): string {
  const decrypted = crypto.privateDecrypt(
    {
      key: privateKey,
      padding: crypto.constants.RSA_PKCS1_OAEP_PADDING,
      oaepHash: "sha256",
    },
    Buffer.from(encryptedMessage, "base64")
  );
  return decrypted.toString("utf8");
}

const { publicKey, privateKey } = generateKeys();

function startEncryptionProcess() {
  rl.question("Digite a mensagem que deseja cifrar: ", (inputMessage) => {
    const encryptedMessage = encryptMessage(publicKey, inputMessage);
    console.log("\nMensagem Cifrada:", encryptedMessage);

    const decryptedMessage = decryptMessage(privateKey, encryptedMessage);
    console.log("Mensagem Decifrada:", decryptedMessage);

    rl.close();
  });
}

startEncryptionProcess();