Java

JWE using AES Key Wrap and AES_128_CBC_HMAC_SHA_256

See more JSON Web Encryption (JWE) Examples

This example duplicates the example A.3 in RFC 7516 for JSON Web Encryption (JWE).

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.StringBuilder;

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: {"alg":"A128KW","enc":"A128CBC-HS256"}
        JsonObject jweProtHdr = new JsonObject();
        jweProtHdr.appendString("alg", "A128KW");
        jweProtHdr.appendString("enc", "A128CBC-HS256");
        jwe.setProtectedHeader(jweProtHdr);

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

        // The example A.3 in RFC 7516 uses the following 128-bit AES key,
        // specified in JWK (JSON Web Key) format:
        //      {"kty":"oct",
        //       "k":"GawgguFyGrWKav7AX4VKUg"
        //      }
        // This is just a way of saying: The key type ("kty") is
        // a bunch of octets ("k") in base64url encoding.
        // We can simply set the AES wrapping key like this:
        String aesWrappingKey = "GawgguFyGrWKav7AX4VKUg";
        jwe.setWrappingKey(0, aesWrappingKey, "base64url");

        // 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 that was just produced.
        // 1) Load the JWE.
        // 2) Set the AES wrapping key.
        // 3) Decrypt.
        Jwe jwe2 = new Jwe();
        String originalPlaintext;
        try {
            jwe2.loadJwe(strJwe);

            // Set the AES wrap key.
            jwe2.setWrappingKey(0, aesWrappingKey, "base64url");

            // 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);

        // ---------------------------------------------------------------------------------
        // It should also be possible to decrypt the JWE as shown in RFC 7516, Appendix A.3.7
        // because it was produced using the same AES Wrap key.

        StringBuilder sbJwe = new StringBuilder();
        sbJwe.append("eyJhbGciOiJBMTI4S1ciLCJlbmMiOiJBMTI4Q0JDLUhTMjU2In0.");
        sbJwe.append("6KB707dM9YTIgHtLvtgWQ8mKwboJW3of9locizkDTHzBC2IlrT1oOQ.");
        sbJwe.append("AxY8DCtDaGlsbGljb3RoZQ.");
        sbJwe.append("KDlTtXchhZTGufMYmOYGS4HffxPSUrfmqCHXaI9wOGY.");
        sbJwe.append("U0m_YmjN04DJvceFICbCVQ");

        try {
            jwe2.loadJweSb(sbJwe);

            jwe2.setWrappingKey(0, aesWrappingKey, "base64url");

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

        System.out.println(originalPlaintext);
    }
}