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.

Java

import com.chilkatsoft.*;

public class ChilkatExample {

  static {
    try {
        System.loadLibrary("chilkat");
    } catch (UnsatisfiedLinkError e) {
      System.err.println("Native code library failed to load.\n" + e);
      System.exit(1);
    }
  }

  public static void main(String argv[])
  {
    boolean success = false;

    // 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.

    CkPublicKey pubKey = new CkPublicKey();
    success = pubKey.LoadFromFile("qa_data/pem/rsa_public.pem");

    CkJwt jwt = new CkJwt();

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

    // First verify the signature.
    boolean sigVerified = jwt.VerifyJwtPk(token,pubKey);
    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.
    CkJsonObject json = new CkJsonObject();
    success = json.Load(payload);
    json.put_EmitCompact(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.
    success = json.Load(joseHeader);
    json.put_EmitCompact(false);
    System.out.println(json.emit());
  }
}