Java Requires Chilkat v11.0.0+

Verify Okta Access Token Locally

See more Okta OAuth/OIDC Examples

This example demonstrates how to validate an Okta access token using Chilkat's JWT class. Chilkat2 Java

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

public class ChilkatExample {

    public static void main(String[] args) {
        // This example assumes the Chilkat API to have been previously unlocked.
        // See Global Unlock Sample for sample code.

        // This example begins with two JSON files:
        //
        // 1. The access token obtained from Okta as shown in one fo these examples:
        //    Get Okta Token using Resource Owner Password Flow
        //
        // 2. The Okta web keys obtained by this example:  Get Okta Web Keys
        //
        //

        // Load the access token to be verified.
        // It contains JSON that looks like this:
        // {
        //   "access_token": "eyJraWQiOiJhb ... O_eVu-kBp6g",
        //   "token_type": "Bearer",
        //   "expires_in": 3600,
        //   "scope": "openid",
        //   "id_token": "eyJraWQi ... FrL9WOuwbQtUg"
        // }
        // This example verifies the access_token.  (The id_token is verified in this example:  Verify Okta ID Token

        JsonObject jsonToken = new JsonObject();
        jsonToken.loadFile("qa_data/tokens/okta_access_token.json");

        // Load the public keys (Okta web keys), one of which is needed to validate.
        // The web keys JSON looks like this:
        // {
        //   "keys": [
        //     {
        //       "kty": "RSA",
        //       "alg": "RS256",
        //       "kid": "anSaRDPfWGOSCVNZEIZB9quCbNsdsvl5uWGBzxbudWQ",
        //       "use": "sig",
        //       "e": "AQAB",
        //       "n": "jT8uAgd5w ... euLB1HaVw"
        //     },
        //     {
        //     ...
        //     }
        //   ]
        // }

        JsonObject jsonWebKeys = new JsonObject();
        jsonWebKeys.loadFile("qa_data/tokens/okta_web_keys.json");

        // ------------------------
        // Step 1: Get the JOSE header from the JWT.  The JOSE header contains JSON.  One of the JSON members will be the key ID "kid" which identifies the web key to be used for validation.
        //
        Jwt jwt = new Jwt();
        String accessToken = jsonToken.stringOf("access_token");
        String joseHeader = jwt.getHeader(accessToken);

        System.out.println(joseHeader);
        // The joseHeader contains this:   {"kid":"anSaRDPfWGOSCVNZEIZB9quCbNsdsvl5uWGBzxbudWQ","alg":"RS256"}

        JsonObject json = new JsonObject();
        json.load(joseHeader);
        String kid = json.stringOf("kid");
        System.out.println("kid to find: " + kid);

        // ------------------------
        // Step 2: Find the key with the same "kid" in the Okta web keys.

        StringBuilder sbKid = new StringBuilder();
        String e = "";
        String n = "";

        int i = 0;
        int count_i = jsonWebKeys.sizeOfArray("keys");
        boolean bFound = false;
        int iMatch = 0;
        while ((!bFound) && (i < count_i)) {
            jsonWebKeys.setI(i);
            sbKid.clear();
            jsonWebKeys.stringOfSb("keys[i].kid", sbKid);
            System.out.println("checking kid: " + sbKid.getAsString());

            if (sbKid.contentsEqual(kid, true)) {
                e = jsonWebKeys.stringOf("keys[i].e");
                n = jsonWebKeys.stringOf("keys[i].n");
                // Exit the loop.
                System.out.println("Found matching kid.");
                iMatch = i;
                bFound = true;
            }

            i = i + 1;
        }

        if (!bFound) {
            System.out.println("No matching key ID found.");
            return;
        }

        System.out.println("Matching key:");
        System.out.println("  exponent = " + e);
        System.out.println("  modulus = " + n);

        // ------------------------
        // Step 3: Load the RSA modulus and exponent into a Chilkat public key object.
        PublicKey pubkey = new PublicKey();

        // Get the matching JSON key from the array of keys.
        jsonWebKeys.setI(iMatch);

        JsonObject jsonWebKey = new JsonObject();
        jsonWebKeys.objectOf2("keys[i]", jsonWebKey);

        try {
            pubkey.loadFromString(jsonWebKey.emit());
        } catch (ChilkatException ex) {
            System.out.println("Failed to load JSON web key.");
            System.out.println(jsonWebKey.emit());
            System.out.println(ex.getLastErrorText());
            return;
        }

        System.out.println("successfully loaded web key.");

        // OK.. we have the desired JSON web key loaded into our public key object.
        // Now we can verify the access token.

        // ------------------------
        // Step 4: Verify the access token.
        try {
            jwt.verifyJwtPk(accessToken, pubkey);
            System.out.println("The access token is valid.");
        } catch (ChilkatException ex) {
            System.out.println("The access token is NOT valid.");
        }
    }
}