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Insecure encryption algorithm - SHA1

Need​

Upgrade encryption algorithm to a secure and robust option

Context​

  • Usage of Java 8 for developing applications with enhanced features and performance
  • Usage of javax.servlet-api for building Java web applications with Servlets
  • Usage of java.security for implementing security features in Java applications

Description​

Non compliant code​

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

public class EncryptionServlet extends javax.servlet.http.HttpServlet {

    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws javax.servlet.ServletException, IOException {
        String password = request.getParameter("password");
        String encryptedPassword = encryptPassword(password);
        // ... rest of the code ...
    }

    private String encryptPassword(String password) {
        MessageDigest md = null;
        try {
            md = MessageDigest.getInstance("SHA-1");
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        }
        byte[] result = md.digest(password.getBytes());
        StringBuffer sb = new StringBuffer();
        for (byte b : result) {
            sb.append(String.format("%02x", b));
        }
        return sb.toString();
    }
}

The above code is a Servlet that handles HTTP POST requests. It reads a password from the request parameters and then encrypts it using the SHA-1 algorithm, which is considered insecure.

The encryption is done in the encryptPassword method. This method uses the MessageDigest class from the java.security package to create an instance of the SHA-1 algorithm. It then digests the password bytes and converts the result into a hexadecimal string.

The main vulnerability here is the usage of the SHA-1 algorithm for encryption. SHA-1 is no longer considered secure against well-funded attackers. In cryptographic hash functions, it is crucial to use a secure algorithm to ensure the integrity and security of the data. Using an insecure algorithm like SHA-1 can lead to vulnerabilities like collision attacks, where two different inputs produce the same hash output, thus compromising the security of the application.

Steps​

  • Replace the insecure encryption algorithm SHA-1 with a stronger algorithm.
  • Use a secure hashing algorithm like SHA-256 or bcrypt for password encryption.
  • Update the code to use the new encryption algorithm.
  • Ensure that the new encryption algorithm is supported by the server environment.
  • Test the updated code thoroughly to ensure it functions correctly.

Compliant code​

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

public class EncryptionServlet extends javax.servlet.http.HttpServlet {

    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws javax.servlet.ServletException, IOException {
        String password = request.getParameter("password");
        String encryptedPassword = encryptPassword(password);
        // ... rest of the code ...
    }

    private String encryptPassword(String password) {
        MessageDigest md = null;
        try {
            md = MessageDigest.getInstance("SHA-256");
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        }
        byte[] result = md.digest(password.getBytes());
        StringBuffer sb = new StringBuffer();
        for (byte b : result) {
            sb.append(String.format("%02x", b));
        }
        return sb.toString();
    }
}

The original code was using the SHA-1 algorithm for password encryption, which is considered insecure due to its vulnerability to collision attacks. In the updated code, the SHA-1 algorithm has been replaced with the SHA-256 algorithm, which is currently considered secure for password encryption.

In the encryptPassword method, the MessageDigest instance is now created with the "SHA-256" algorithm instead of "SHA-1". The rest of the method remains the same, as it simply performs the hashing operation and formats the result into a hexadecimal string.

Please ensure that the server environment supports the SHA-256 algorithm. After updating the code, it is crucial to test it thoroughly to ensure that the password encryption and the overall functionality of the application are working as expected.

References​

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