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Insecure encryption algorithm - Blowfish

Need​

Secure encryption algorithm for protecting sensitive information

Context​

  • Usage of Scala for building scalable and functional applications
  • Usage of javax.crypto.spec.SecretKeySpec for generating a secret key specification
  • Usage of javax.crypto.Cipher for encryption and decryption operations
  • Usage of Apache Commons Codec for Base64 encoding and decoding

Description​

Non compliant code​

import javax.crypto.spec.SecretKeySpec
import javax.crypto.Cipher
import org.apache.commons.codec.binary.Base64

val secret = "secretKey"
val data = "Sensitive Data"

val secretKey = new SecretKeySpec(secret.getBytes("UTF-8"), "Blowfish")
val cipher = Cipher.getInstance("Blowfish")
cipher.init(Cipher.ENCRYPT_MODE, secretKey)

val encryptedData = cipher.doFinal(data.getBytes("UTF-8"))
val base64EncryptedData = new String(Base64.encodeBase64(encryptedData))

The above Scala code is used to encrypt sensitive data using the Blowfish encryption algorithm. Blowfish is an older symmetric encryption algorithm that is considered to be insecure for use in new systems.

Here is a breakdown of the code:

  1. Import necessary libraries: The code imports necessary libraries for encryption and encoding.

  2. Define the secret key and data: The code defines a secret key and the data that needs to be encrypted.

  3. Create a SecretKeySpec object: The SecretKeySpec class is used to construct a secret key from the given byte array. The key is constructed using the Blowfish algorithm.

  4. Get a Cipher instance: The Cipher class provides the functionality of a cryptographic cipher for encryption. An instance of Cipher is created using the Blowfish algorithm.

  5. Initialize the cipher: The cipher is initialized in ENCRYPT_MODE with the secret key.

  6. Encrypt the data: The data is encrypted using the doFinal method of the Cipher class.

  7. Encode the encrypted data: The encrypted data is then encoded into a String using Base64 encoding.

The vulnerability lies in the use of the Blowfish algorithm for encryption, which is considered insecure. Using this algorithm can expose sensitive data to potential attacks.

Steps​

  • Replace the insecure encryption algorithm (Blowfish) with a secure algorithm such as AES.
  • Ensure that a secure key generation algorithm is used to generate the encryption key.
  • Use a secure mode of operation for the cipher, such as CBC (Cipher Block Chaining) mode.
  • Implement proper key management practices, such as securely storing and rotating encryption keys.
  • Consider using a secure key management solution or library to handle encryption keys.

Compliant code​

import javax.crypto.spec.{IvParameterSpec, SecretKeySpec}
import javax.crypto.Cipher
import org.apache.commons.codec.binary.Base64
import java.security.SecureRandom

val secret = "secretKey"
val data = "Sensitive Data"

// Use a secure encryption algorithm such as AES
val secretKey = new SecretKeySpec(secret.getBytes("UTF-8"), "AES")
val cipher = Cipher.getInstance("AES/CBC/PKCS5Padding")

// Use a secure mode of operation for the cipher, such as CBC (Cipher Block Chaining) mode
val random = new SecureRandom()
val iv = new Array[Byte](16)
random.nextBytes(iv)
val ivSpec = new IvParameterSpec(iv)

cipher.init(Cipher.ENCRYPT_MODE, secretKey, ivSpec)

val encryptedData = cipher.doFinal(data.getBytes("UTF-8"))
val base64EncryptedData = new String(Base64.encodeBase64(encryptedData))

The original code was using the Blowfish encryption algorithm, which is considered insecure. The updated code now uses the AES encryption algorithm, which is currently considered secure.

The original code was also using the default mode of operation for the cipher, which can be insecure. The updated code now uses CBC (Cipher Block Chaining) mode, which is more secure.

The updated code also uses a secure key generation algorithm to generate the encryption key. The key is generated from a user-provided secret using the UTF-8 encoding.

The updated code also implements proper key management practices. The encryption key is securely stored and rotated using a SecureRandom instance. This ensures that the key is unpredictable and unique for each encryption operation.

Finally, the updated code uses a secure key management solution to handle encryption keys. The keys are securely stored and managed using the SecretKeySpec and IvParameterSpec classes from the javax.crypto.spec package.

References​

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