Skip to main content

Insecure encryption algorithm - Insecure Elliptic Curve

Need​

Secure encryption algorithm - Strong Elliptic Curve

Context​

  • Usage of Java 8 for developing applications with enhanced features and performance improvements
  • Usage of javax.crypto for cryptographic operations in Java
  • Usage of javax.servlet.http for handling HTTP requests and responses in Java Servlets
  • Usage of java.security for implementing security features in Java applications
  • Usage of java.security.spec for working with cryptographic algorithms and security specifications in Java

Description​

Non compliant code​

import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.SecureRandom;
import java.security.spec.ECGenParameterSpec;
import javax.crypto.KeyAgreement;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class VulnerableServlet extends HttpServlet {
    protected void doGet(HttpServletRequest request, HttpServletResponse response) {
        try {
            KeyPairGenerator kpg = KeyPairGenerator.getInstance("EC");
            ECGenParameterSpec ecSpec = new ECGenParameterSpec("sect113r1");
            kpg.initialize(ecSpec, new SecureRandom());
            KeyPair kp = kpg.generateKeyPair();

            KeyAgreement ka = KeyAgreement.getInstance("ECDH");
            ka.init(kp.getPrivate());

        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

The above Java code shows a scenario where an insecure elliptic curve, sect113r1, is being used for key generation in an encryption process. This curve is considered weak and insecure for cryptographic operations.

The VulnerableServlet class extends HttpServlet and overrides the doGet method. Inside this method, an instance of KeyPairGenerator is created with the "EC" (Elliptic Curve) algorithm.

Then, an ECGenParameterSpec object is instantiated with the insecure sect113r1 curve. This object is then used to initialize the KeyPairGenerator along with a SecureRandom object.

Following this, a KeyPair is generated using the KeyPairGenerator.

A KeyAgreement object is then created with the "ECDH" (Elliptic Curve Diffie-Hellman) algorithm, and is initialized with the private key from the KeyPair.

The problem here is the use of the sect113r1 curve. This curve is known to be weak, and using it for cryptographic operations can lead to vulnerabilities such as easier brute force attacks or other cryptographic attacks. This can potentially expose sensitive information that is being encrypted using keys generated with this curve.

Steps​

  • Replace the insecure elliptic curve with a secure elliptic curve.
  • Use a strong encryption algorithm for key generation and key agreement.
  • Ensure that the key size is appropriate for the desired level of security.
  • Regularly update the cryptographic libraries and algorithms used in the system.
  • Follow best practices and guidelines for secure encryption and key management.

Compliant code​

import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.SecureRandom;
import java.security.spec.ECGenParameterSpec;
import javax.crypto.KeyAgreement;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class SecureServlet extends HttpServlet {
    protected void doGet(HttpServletRequest request, HttpServletResponse response) {
        try {
            KeyPairGenerator kpg = KeyPairGenerator.getInstance("EC");
            ECGenParameterSpec ecSpec = new ECGenParameterSpec("secp256r1"); // Use a secure elliptic curve
            kpg.initialize(ecSpec, new SecureRandom());
            KeyPair kp = kpg.generateKeyPair();

            KeyAgreement ka = KeyAgreement.getInstance("ECDH");
            ka.init(kp.getPrivate());

        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

The original code was using an insecure elliptic curve ("sect113r1") for key generation. This curve is not considered secure anymore due to its small size. The new code uses a more secure elliptic curve ("secp256r1"), which provides a higher level of security.

The KeyPairGenerator instance is initialized with the secure elliptic curve specification and a SecureRandom object. This ensures that the keys generated are random and secure.

The KeyAgreement instance is initialized with the private key from the generated KeyPair. This is used for the Elliptic Curve Diffie-Hellman (ECDH) key agreement protocol, which allows two parties, each having an elliptic curve public-private key pair, to establish a shared secret over an insecure channel.

It's important to regularly update the cryptographic libraries and algorithms used in the system to ensure they are secure and up-to-date. Following best practices and guidelines for secure encryption and key management is also crucial for maintaining the security of the system.

References​

Last updated on