Java Requires Chilkat v11.5.0+

Create JWS Using Private Key on a Smart Card

See more JSON Web Signatures (JWS) Examples

Creates and validates a JSON Web Signature (JWS) using the private key associated with a certificate on a smart card. Chilkat2 Java

import com.chilkatsoft.chilkat2.Cert;
import com.chilkatsoft.chilkat2.ChilkatException;
import com.chilkatsoft.chilkat2.JsonObject;
import com.chilkatsoft.chilkat2.Jws;
import com.chilkatsoft.chilkat2.PublicKey;

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.

        // Load the certificate from a smart card.
        Cert cert = new Cert();

        // Set the smarcard PIN prior to loading
        cert.setSmartCardPin("123456");

        // Detect the connected smartcard or USB security token and load the default certificate.
        try {
            cert.loadFromSmartcard("");
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        // Note: Chilkat provides many different ways to load a certificate from a smartcard or USB token,
        // such as selecting a certificate if the card contains multiple certificates with private keys,
        // or working with lower-level PKCS11 or ScMinidriver API's (both of which Chilkat provides).

        // Create the JWS Protected Header
        JsonObject jwsProtHdr = new JsonObject();

        if (cert.isEcdsa()) {
            jwsProtHdr.appendString("alg", "ES256");
        } else {
            jwsProtHdr.appendString("alg", "RS256");
        }

        Jws jws = new Jws();

        // Set the protected header:
        int signatureIndex = 0;
        jws.setProtectedHeader(signatureIndex, jwsProtHdr);

        // Provide the private key via the certificate.
        // This requires Chilkat v11.5.0 or greater.
        jws.setSigningCert(signatureIndex, cert);

        // Set the payload.
        boolean bIncludeBom = false;
        String payloadStr = "In our village, folks say God crumbles up the old moon into stars.";
        jws.setPayload(payloadStr, "utf-8", bIncludeBom);

        // Create the JWS
        // By default, the compact serialization is used.
        String jwsCompact;
        try {
            jwsCompact = jws.createJws();
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        System.out.println("JWS: " + jwsCompact);

        // sample output:
        // JWS: eyJhbGciOiJQUzI1NiJ9.SW4gb3VyIHZpbGxhZ2UsIGZvbGtzIHNheSBHb2QgY3J1bWJsZXMgdXAgdGhlIG9sZCBtb29uIGludG8gc3RhcnMu.TRWhwRo5dMv9-8OzrInfJTwmUGYgjLfHk8lqF072ND-FmLWEBnUTOpY8oJXp8FdWw2SalbdOeNlrtlJjwk4XK8Ql2iJ_2qMCtxsvLPhKBOqFoAF4aBvTOEDVJDxf0DaBSiydEEtfTVV2iwBcjWabu5J2XieR5y7QZQtuHsn7T3qKBvCcCejN3Y2oqAT3qMHvu1fTms1r_91wBn_K7Wjd9UkZ1n02qQcUHJznR_OF2BgN7_KWIDAF9ZS9keoju2NPpPelO4yxa2XUPnehY3G7dHKoCxUEQR4d2Xc5voqDASTVCDqQS4PVOZdvT3Ein6-SanAlCwbWBbkvT8g6-5PImQ

        // Now load the JWS, validate, and recover the original text.
        Jws jws2 = new Jws();

        // Load the JWS.
        jws2.loadJws(jwsCompact);

        PublicKey pubKey = new PublicKey();
        cert.getPublicKey(pubKey);

        // Set the public key used for validation.
        signatureIndex = 0;
        jws2.setPublicKey(signatureIndex, pubKey);

        // Validate the 1st (and only) signature at index 0..
        int v = jws2.validate(signatureIndex);
        if (v < 0) {
            // Perhaps Chilkat was not unlocked or the trial expired..
            System.out.println("Method call failed for some other reason.");
            System.out.println(jws2.getLastErrorText());
            return;
        }

        if (v == 0) {
            System.out.println("Invalid signature.  The key was incorrect, the JWS was invalid, or both.");
            return;
        }

        // If we get here, the signature was validated..
        System.out.println("Signature validated.");

        // Recover the original content:
        System.out.println(jws2.getPayload("utf-8"));

        // Examine the protected header:

        JsonObject joseHeader = new JsonObject();
        try {
            jws2.getProtectedH(signatureIndex, joseHeader);
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        joseHeader.setEmitCompact(false);

        System.out.println("Protected (JOSE) header:");
        System.out.println(joseHeader.emit());

        // Output:

        //     Signature validated.
        //     In our village, folks say God crumbles up the old moon into stars.
        //     Protected (JOSE) header:
        //     {
        //       "alg": "RS256"
        //     }
    }
}