Java

JWE using PBES2 Key Wrapping

See more JSON Web Encryption (JWE) Examples

Demonstrates how to create and decrypt a JWE that using PBES2 key wrapping.

This example demonstrates PBES2 with HMAC SHA-256 and A128KW wrapping. It is also possible to do the following by simply changing the "alg" parameter:

• PBES2 with HMAC SHA-384 and A192KW wrapping
• PBES2 with HMAC SHA-512 and A256KW wrapping

Note: This example requires Chilkat v9.5.0.66 or greater.

Chilkat2 Java

import com.chilkatsoft.chilkat2.ChilkatException;
import com.chilkatsoft.chilkat2.JsonObject;
import com.chilkatsoft.chilkat2.Jwe;
import com.chilkatsoft.chilkat2.Prng;

public class ChilkatExample {

    public static void main(String[] args) {
        // This requires the Chilkat API to have been previously unlocked.
        // See Global Unlock Sample for sample code.

        // Note: This example requires Chilkat v9.5.0.66 or greater.

        String plaintext = "Live long and prosper.";

        Jwe jwe = new Jwe();

        // First build the JWE Protected Header..
        JsonObject jweProtHdr = new JsonObject();
        jweProtHdr.appendString("alg", "PBES2-HS256+A128KW");
        jweProtHdr.appendString("enc", "A128GCM");

        // PBES2 requires two additional parameters:
        // 1) A random salt parameter ("p2s") containing 8 or more bytes in base64url format.
        // 2) An iteration count parameter ("p2c").  A minimum count of 1000 is recommended.
        //    The iteration count is intended to make the PBES2 computation more expensive (time consuming)
        //    to prevent brute-force attacks.
        Prng prng = new Prng();
        jweProtHdr.appendString("p2s", prng.genRandom(16, "base64url"));
        jweProtHdr.appendString("p2c", "1000");

        System.out.println("JWE Protected Header: " + jweProtHdr.emit());
        System.out.println("--");

        // Don't forget to actually provide the protected header to the JWE object:
        jwe.setProtectedHeader(jweProtHdr);

        // Set the PBES2 password
        int recipientIndex = 0;
        jwe.setPassword(recipientIndex, "top secret");

        // Encrypt and return the JWE:
        String strJwe;
        try {
            strJwe = jwe.encrypt(plaintext, "utf-8");
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        // Show the JWE we just created:
        System.out.println(strJwe);

        // Decrypt the JWE.
        Jwe jwe2 = new Jwe();
        String originalPlaintext;
        try {
            jwe2.loadJwe(strJwe);

            // Set the PBES2 password
            jwe2.setPassword(recipientIndex, "top secret");

            // Decrypt.
            originalPlaintext = jwe2.decrypt(0, "utf-8");
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        System.out.println("original text: ");
        System.out.println(originalPlaintext);

        // Sample output:

        // JWE Protected Header: {"alg":"PBES2-HS256+A128KW","enc":"A128GCM","p2s":"z39rTEfRy1T1Yn_D1mZRlg","p2c":"1000"}
        // --
        // eyJhbGciOiJQQkVTMi1IUzI1NitBMTI4S1ciLCJlbmMiOiJBMTI4R0NNIiwicDJzIjoiejM5clRFZlJ5MVQxWW5fRDFtWlJsZyIsInAyYyI6IjEwMDAifQ.koYt6PrFmYwcwdcT7ZcvXHA1d-Xez5h4.luGlbvEnZp-7IsBOj42Yhw.YMTcfLf8Qe4zazozGV2OAu3cUdQ8Kg.rWub47ESWkc6IqZJTvSTmg
        // original text:
        // Live long and prosper.
    }
}