Java

Verify JWT with EdDSA / Ed25519 Signature

See more JSON Web Token (JWT) Examples

Note: This example requires Chilkat v9.5.0.84 or greater.

Demonstrates how to verify a JWT that was signed using an Ed25519 private key.

This example verifies the EdDSA signature. It also does the following:

• Checks to see if the time constraints ("nbf" and "exp") are valid.
• Recovers the original JOSE header.
• Recovers the original data.

Chilkat2 Java

import com.chilkatsoft.chilkat2.ChilkatException;
import com.chilkatsoft.chilkat2.Jwt;
import com.chilkatsoft.chilkat2.PublicKey;

public class ChilkatExample {

    public static void main(String[] args) {
        // Demonstrates how to verify a JWT with an EdDSA/Ed25519 Signature
        // *** Requires Chilkat v9.5.0.84 or greater.

        // This example assumes the Chilkat API to have been previously unlocked.
        // See Global Unlock Sample for sample code.

        // Use this Ed25519 public key for verification

        String jsonPubKey = "{\"kty\": \"OKP\",\"alg\": \"EdDSA\",\"crv\": \"Ed25519\",\"x\": \"11qYAYKxCrfVS_7TyWQHOg7hcvPapiMlrwIaaPcHURo\"}";

        PublicKey pubKey = new PublicKey();
        try {
            pubKey.loadFromString(jsonPubKey);
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        Jwt jwt = new Jwt();
        String token = "eyJhbGciOiJFZERTQSJ9.RXhhbXBsZSBvZiBFZDI1NTE5IHNpZ25pbmc.hgyY0il_MGCjP0JzlnLWG1PPOt7-09PGcvMg3AIbQR6dWbhijcNR4ki4iylGjg5BhVsPt9g7sVvpAr_MuM0KAg";

        // First verify the signature.
        boolean sigVerified;
        try {
            jwt.verifyJwtPk(token, pubKey);
            sigVerified = true;
        } catch (ChilkatException e) {
            sigVerified = false;
        }
        System.out.println("verified: " + sigVerified);

        if (!sigVerified) {
            System.out.println(jwt.getLastErrorText());
            return;
        }

        // Let's see if the time constraints, if any, are valid.
        // The above JWT was created on the afternoon of 16-May-2016, with an expiration of 1 hour.
        // If the current system time is before the "nbf" time, or after the "exp" time,
        // then IsTimeValid will return false/0.
        // Also, we'll allow a leeway of 60 seconds to account for any clock skew.
        // Note: If the token has no "nbf" or "exp" claim fields, then IsTimeValid is always true.
        int leeway = 60;
        boolean bTimeValid = jwt.isTimeValid(token, leeway);
        System.out.println("time constraints valid: " + bTimeValid);

        // Recover the original data (the payload).
        String payload = jwt.getPayload(token);
        System.out.println(payload);

        // Recover the original JOSE header in the same way:
        String joseHeader = jwt.getHeader(token);
        System.out.println(joseHeader);
    }
}