Java

Verify JWT Using HS256, HS384, or HS512

See more JSON Web Token (JWT) Examples

Demonstrates how to verify a JWT that was signed using HS256, HS384, or HS512. (HS256 is JWT's acronym for HMAC-SHA256.)

This example verifies the 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;

public class ChilkatExample {

    public static void main(String[] args) {
        // Demonstrates how to verify an HMAC JWT using a shared secret (password).

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

        Jwt jwt = new Jwt();

        String token = "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpc3MiOiJodHRwOi8vZXhhbXBsZS5vcmciLCJzdWIiOiJKb2huIiwiYXVkIjoiaHR0cDovL2V4YW1wbGUuY29tIiwiaWF0IjoxNDYzNDMxODEyLCJuYmYiOjE0NjM0MzE4MTIsImV4cCI6MTQ2MzQzNTQxMn0.SHnMJ11qJH5pbp22YchT_9fL2HIx0koHiUHLG67_foU";

        // First verify the signature.
        // The password used to create this JWT was "secret".
        boolean sigVerified;
        try {
            jwt.verifyJwt(token, "secret");
            sigVerified = true;
        } catch (ChilkatException e) {
            sigVerified = false;
        }
        System.out.println("with correct password: " + sigVerified);

        // Now try with a different password:
        try {
            jwt.verifyJwt(token, "secret2");
            sigVerified = true;
        } catch (ChilkatException e) {
            sigVerified = false;
        }
        System.out.println("with incorrect password " + 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());
    }
}