Insecure encryption algorithm - TripleDES

Need

Implementation of secure encryption algorithms and modes

Context

• Usage of TypeScript for statically typed JavaScript development
• Usage of Express for building web applications and APIs
• Usage of crypto for cryptographic operations

Description

Non compliant code

import express from 'express';
import crypto from 'crypto';

const app = express();

app.get('/encrypt', (req, res) => {
  const data = req.query.data;
  const key = req.query.key;

  const cipher = crypto.createCipher('des-ede3', key);
  let encryptedData = cipher.update(data, 'utf8', 'hex');
  encryptedData += cipher.final('hex');

  res.send(encryptedData);
});

app.listen(3000, () => {
  console.log('Server is running on port 3000');
});

The vulnerability in this code is the use of an insecure encryption algorithm, specifically TripleDES (DES-EDE3). The crypto.createCipher function is used to create a cipher object with the TripleDES algorithm, but this algorithm is considered insecure.

Using an insecure encryption algorithm can lead to the compromise of sensitive information. In this case, an attacker could potentially reverse the encryption process and retrieve the original sensitive data.

Additionally, the code does not specify a mode of operation for the encryption algorithm, which defaults to the Electronic Codebook (ECB) mode. ECB mode is known to be insecure because it does not provide proper data confidentiality and can lead to patterns in the encrypted data.

The impact of this vulnerability is that an attacker could potentially reverse the encryption process and obtain the sensitive information being encrypted.

The recommended solution is to use a secure encryption algorithm, such as AES (Advanced Encryption Standard), and to use a secure mode of operation, such as CBC (Cipher Block Chaining) or GCM (Galois/Counter Mode).

Steps

• Replace the insecure encryption algorithm TripleDES with a secure encryption algorithm like AES.
• Ensure that the encryption algorithm is used in a secure mode, such as CBC (Cipher Block Chaining) mode.
• Use a secure key generation method to generate the encryption key.
• Implement proper error handling for the encryption process.
• Consider using a secure key management system to store and manage encryption keys.

Compliant code

import express from 'express';
import crypto from 'crypto';

const app = express();

app.get('/encrypt', (req, res) => {
  const data = req.query.data;
  const key = req.query.key;

  const iv = crypto.randomBytes(16); // Generate a random initialization vector

  const cipher = crypto.createCipheriv('aes-256-cbc', key, iv);
  let encryptedData = cipher.update(data, 'utf8', 'hex');
  encryptedData += cipher.final('hex');

  res.send({
    iv: iv.toString('hex'),
    encryptedData: encryptedData
  });
});

app.listen(3000, () => {
  console.log('Server is running on port 3000');
});

The fixed code addresses the vulnerability by using a secure encryption algorithm, specifically AES-256 in CBC mode. Here's an explanation of the changes made:

1. The code imports the necessary modules, express for creating the server and crypto for cryptographic operations.

2. The code creates an instance of the Express application using express().

3. The code defines a route handler for the /encrypt endpoint using app.get('/encrypt', ...). This endpoint expects two query parameters: data for the data to be encrypted and key for the encryption key.

4. Inside the route handler, the code generates a random initialization vector (IV) using crypto.randomBytes(16). The IV is used to add randomness to the encryption process.

5. The code creates a cipher object using crypto.createCipheriv('aes-256-cbc', key, iv). It uses the AES-256 algorithm in CBC mode, which is considered secure.

6. The code encrypts the data by calling cipher.update(data, 'utf8', 'hex') to process the input data in UTF-8 encoding and obtain the encrypted data in hexadecimal format. The encrypted data is then finalized using cipher.final('hex') and appended to the encrypted data string.

7. Finally, the code sends the response to the client with the IV and the encrypted data in an object format.

8. The code starts the server on port 3000 using app.listen(3000, ...).

References

• 264.Insecure encryption algorithm - TripleDES