Java

Verify JWT Using an RSA Public Key (RS256, RS384, RS512)

See more JSON Web Token (JWT) Examples

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

This example verifies the RSA 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 claims JSON.

Chilkat2 Java

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

public class ChilkatExample {

    public static void main(String[] args) {
        // Demonstrates how to verify an JWT using an RSA public key.

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

        PublicKey pubKey = new PublicKey();
        pubKey.loadFromFile("qa_data/pem/rsa_public.pem");

        Jwt jwt = new Jwt();

        String token = "eyJhbGciOiJSUzI1NiIsInR5cCI6IkpXVCJ9.eyJpc3MiOiJodHRwOi8vZXhhbXBsZS5vcmciLCJzdWIiOiJKb2huIiwiYXVkIjoiaHR0cDovL2V4YW1wbGUuY29tIiwiaWF0IjoxNDYzNDQ1MjM4LCJuYmYiOjE0NjM0NDUyMzgsImV4cCI6MTQ2MzQ0ODgzOH0.XRtqed6nuJ9lrp0wbNdDX3fCkSh_d9cHAniPbNcqm7G-5N3mtI5ntQvZBDP3pHtECVqufuDwW7XgUtzAi0ZXhyiRm1iZ3wMSN5lHWv52OQJmMHPA7VPd8Q1hDG-tx-QswzJKd75OEUHP7wIXq2Mg_YVElfDvJI6TGjGyS1y-RLHlz-ldlGsEwIBkO0PtzIYTVov97x8p9KCsPNhS4lZUIqKOYoTZUV5LpuAWARl-636DfMEB_A5_IEaw_W8leh2suP2ULVZxwE-Tk1kBC9tsSGrBrPTtg7sziaV4Lbb0JRANmh98uTRu5f8ji9CVOnpbMiAzjsJSy56kz_olweXSuA";

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

        // 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);

        // Now let's recover the original claims JSON (the payload).
        String payload = jwt.getPayload(token);
        // The payload will likely be in compact form:
        System.out.println(payload);

        // We can format for human viewing by loading it into Chilkat's JSON object
        // and emit.
        JsonObject json = new JsonObject();
        json.load(payload);
        json.setEmitCompact(false);
        System.out.println(json.emit());

        // We can recover the original JOSE header in the same way:
        String joseHeader = jwt.getHeader(token);
        // The payload will likely be in compact form:
        System.out.println(joseHeader);

        // We can format for human viewing by loading it into Chilkat's JSON object
        // and emit.
        json.load(joseHeader);
        json.setEmitCompact(false);
        System.out.println(json.emit());
    }
}