Java Requires Chilkat v11.5.0+

Box: Get a Service Account Token with JWT

See more Box Examples

Use the encrypted private key in a Box application configuration file to sign a short-lived assertion and exchange it for an access token. Configure and authorize a JWT Server app first. The enterprise subject obtains the service-account token.

See the Box API guide for setup and the complete workflow.

Chilkat2 Java

import com.chilkatsoft.chilkat2.ChilkatException;
import com.chilkatsoft.chilkat2.HttpCurl;
import com.chilkatsoft.chilkat2.JsonObject;
import com.chilkatsoft.chilkat2.Jwt;
import com.chilkatsoft.chilkat2.PrivateKey;
import com.chilkatsoft.chilkat2.Prng;

public class ChilkatExample {

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

        // Requires Chilkat 11.5.0 or later and a previously unlocked Chilkat bundle.
        // See Global Unlock Sample.
        // Guide: Box API Guide.

        success = false;

        JsonObject config = new JsonObject();
        try {
            config.loadFile("qa_data/tokens/box_jwt_config.json");
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        PrivateKey key = new PrivateKey();
        try {
            key.loadEncryptedPem(config.stringOf("boxAppSettings.appAuth.privateKey"), config.stringOf("boxAppSettings.appAuth.passphrase"));
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        JsonObject header = new JsonObject();
        header.updateString("alg", "RS256");
        header.updateString("typ", "JWT");
        header.updateString("kid", config.stringOf("boxAppSettings.appAuth.publicKeyID"));
        Jwt jwt = new Jwt();
        Prng prng = new Prng();
        String nonce;
        try {
            nonce = prng.genRandom(32, "hex");
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        JsonObject claims = new JsonObject();
        claims.updateString("iss", config.stringOf("boxAppSettings.clientID"));
        claims.updateString("sub", config.stringOf("enterpriseID"));
        claims.updateString("box_sub_type", "enterprise");
        claims.updateString("aud", "https://api.box.com/oauth2/token");
        claims.updateString("jti", nonce);
        claims.updateInt("exp", jwt.genNumericDate(45));
        String assertion;
        try {
            assertion = jwt.createJwtPk(header.emit(), claims.emit(), key);
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        HttpCurl curl = new HttpCurl();
        curl.setVar("client_id", config.stringOf("boxAppSettings.clientID"));
        curl.setVar("client_secret", config.stringOf("boxAppSettings.clientSecret"));
        curl.setVar("assertion", assertion);
        curl.clearTargetOutput("*");
        curl.clearVar("access_token");
        curl.addTargetOutput("access_token", "access_token");
        try {
            curl.doYourThing("curl -X POST \"https://api.box.com/oauth2/token\" --data-urlencode \"grant_type=urn:ietf:params:oauth:grant-type:jwt-bearer\" --data-urlencode \"client_id={{client_id}}\" --data-urlencode \"client_secret={{client_secret}}\" --data-urlencode \"assertion={{assertion}}\"");
            success = true;
        } catch (ChilkatException e) {
            success = false;
        }
        if ((!success) || (curl.getStatusCode() != 200)) {
            System.out.println("Box request failed. HTTP status: " + curl.getStatusCode());
            System.out.println("Failure reason: " + curl.getFailReason());
            return;
        }

        if (!curl.varDefined("!")) {
            System.out.println("Expected response fields are missing.");
            return;
        }

        // Reuse the token in this HttpCurl instance. JWT tokens are renewed by making
        // a new assertion/token request, not by using a refresh token.
        System.out.println("JWT access token obtained.");
    }
}