Nodejs AES Text Encrypter/Decrypter.

AES_ENCRYPOR_DECRYPTOR.ts

import {scryptSync, randomBytes, createCipheriv, createDecipheriv} from 'crypto';

export class Encrypter {
  private algorithm: string = 'aes-192-cbc';

  // encryption key for the cipher
  private key: string;

  constructor(key: string) {
    this.key = key;
  }

  encrypt(text: string): string {

    /* 
    *  Creating a sub-internal encryption key for a particular text to be encrypted.
    *  That sub-internal encrypted key is protected by the original system 
    *  "encryption-key" and a unique "salt".
    */
    const buffer = scryptSync(this.key, 'salt', 24);
    
    /* 
    *  Initialization Vector as the initial state for the AES algorithm.
    *  Used for randomization or for non-repeating behaviour.
    */
    const iv = randomBytes(16);
    const cipher = createCipheriv(this.algorithm, buffer, iv);
    const encrypted = cipher.update(text, 'utf8', 'hex');

    return [encrypted + cipher.final('hex'), Buffer.from(iv).toString('hex')].join('|');
  }

  decrypt(encryptedText: string): string {
    const [encrypted, iv] = encryptedText.split('|');

    if (!iv) {
      throw new Error('IV not found');
    }

    const buffer = scryptSync(this.key, 'salt', 24);
    const decipher = createDecipheriv(this.algorithm, buffer, Buffer.from(iv, 'hex'));
    const decrypted = decipher.update(encrypted, 'hex', 'utf8');

    return decrypted + decipher.final('utf8');
  }
}