Java

Get Firebase Access Token from JSON Service Account Private Key

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Demonstrates how to get a Firebase access token using a JSON service account private key. Your Firebase service account can be used to authenticate multiple Firebase features, such as Database, Storage and Auth, programmatically.

A Firebase JSON service account private key can be created in the Firebase settings/admin portion of the console.firebase.google.com site as shown here:

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Chilkat2 Java

import com.chilkatsoft.chilkat2.AuthGoogle;
import com.chilkatsoft.chilkat2.ChilkatException;
import com.chilkatsoft.chilkat2.FileAccess;
import com.chilkatsoft.chilkat2.Socket;

public class ChilkatExample {

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

        // First load the Firebase JSON private key into a string.
        FileAccess fac = new FileAccess();
        String jsonKey;
        try {
            jsonKey = fac.readEntireTextFile("qa_data/firebase/firebase-chilkat-firebase-adminsdk-n28n4-1b664ee163.json", "utf-8");
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        // A Firebase JSON private key should look something like this:

        // {
        //   "type": "service_account",
        //   "project_id": "firebase-chilkat",
        //   "private_key_id": "1c664ee164907413c91ddefcf5b765ecba8779e2",
        //   "private_key": "-----BEGIN PRIVATE KEY-----\nMIIEvQIBA ... Ya2UZii/lXn73/ZOK8=\n-----END PRIVATE KEY-----\n",
        //   "client_email": "firebase-adminsdk-n28n4@firebase-chilkat.iam.gserviceaccount.com",
        //   "client_id": "134846322329335418431",
        //   "auth_uri": "https://accounts.google.com/o/oauth2/auth",
        //   "token_uri": "https://accounts.google.com/o/oauth2/token",
        //   "auth_provider_x509_cert_url": "https://www.googleapis.com/oauth2/v1/certs",
        //   "client_x509_cert_url": "https://www.googleapis.com/robot/v1/metadata/x509/firebase-adminsdk-n28n4%40firebase-chilkat.iam.gserviceaccount.com"
        // }
        //

        AuthGoogle gAuth = new AuthGoogle();
        gAuth.setJsonKey(jsonKey);

        // Choose a scope.
        // The scope could be "https://www.googleapis.com/auth/firebase.database"
        // or a space-delimited list of scopes:
        // "https://www.googleapis.com/auth/firebase.database https://www.googleapis.com/auth/userinfo.email"

        gAuth.setScope("https://www.googleapis.com/auth/firebase.database https://www.googleapis.com/auth/userinfo.email");

        // Request an access token that is valid for this many seconds.
        gAuth.setExpireNumSeconds(3600);

        // If the application is requesting delegated access:
        // The email address of the user for which the application is requesting delegated access,
        // then set the email address here. (Otherwise leave it empty.)
        gAuth.setSubEmailAddress("");

        // Connect to www.googleapis.com using TLS (TLS 1.2 is the default.)
        // The Chilkat socket object is used so that the connection can be established
        // through proxies or an SSH tunnel if desired.
        Socket tlsSock = new Socket();
        try {
            tlsSock.connect("www.googleapis.com", 443, true, 5000);

            // Send the request to obtain the access token.
            gAuth.obtainAccessToken(tlsSock);
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        // Examine the access token:
        System.out.println("Firebase Access Token: " + gAuth.getAccessToken());

        // Save the token to a file (or wherever desired).  This token is valid for 1 hour.
        fac.writeEntireTextFile("qa_data/tokens/firebaseToken.txt", gAuth.getAccessToken(), "utf-8", false);
    }
}