Description

This vulnerability detector identifies JavaScript code that derives initialization vectors (IVs) or nonces from encryption keys. Using key-derived IVs/nonces is a cryptographic weakness that can lead to predictable values, compromising encryption security and potentially allowing attackers to decrypt sensitive data.

Detection Strategy

• Scans JavaScript source code for cryptographic implementations

• Identifies patterns where initialization vectors (IVs) or nonces are mathematically derived from encryption keys

• Flags code that generates IVs/nonces using key material as input to derivation functions

• Reports violations when cryptographic functions use non-random, key-dependent values for initialization parameters

Vulnerable code example

const crypto = require('crypto');

function encryptData(data) {
  const key = crypto.randomBytes(16);
  
  // VULNERABLE: IV reuses the same key bytes, breaking semantic security
  const cipher = crypto.createCipheriv('aes-128-cbc', key, key);
  return Buffer.concat([cipher.update(data), cipher.final()]);...

✅ Secure code example

const crypto = require('crypto');

function encryptData(data) {
  const key = crypto.randomBytes(16);
  
  // SAFE: IV generated independently with randomBytes, not from key
  const iv = crypto.randomBytes(16);
  const cipher = crypto.createCipheriv('aes-128-cbc', key, iv);...