Develop Reference

Google Sheets API access using Service Account from Android Device

Making app in Unity.
App works perfectly in Unity editor:
can access firebase for user login - this isnt the issue
can read and write from/to google sheet located in google drive using service account
When I build to android (apk file), and install on physical andoid device (Samsung S20 phone):
can access firebase for user login - so it is not an network/internet problem
CANT read/write from google sheet.
A portion of my code is here:
Authorisation - i am not sure if this bit works on the phone, or how to check.
public void Auth() // authorise access to the googlesheet online
{
//jsonKey = File.ReadAllText("Assets/Resources/Creds/beerhats-db-3***.json"); // location of key - read it - save to string
TextAsset txtAsset = (TextAsset)Resources.Load("beerhats-db-3***", typeof(TextAsset)); //i changed the file name here on stackoverflow just in case its a security thing
string jsonKey = txtAsset.text;
ServiceAccountCredential.Initializer initializer = new ServiceAccountCredential.Initializer(Secrets.serviceAccountID);
var jsonData = (JObject)JsonConvert.DeserializeObject(jsonKey);
if (jsonData != null) // the json file isnt moving or changing - so probably dont need an if statemet - remove later
{
string privateKey = jsonData["private_key"].Value<string>(); // specifically get the private key from all the data in the json file
ServiceAccountCredential credential = new ServiceAccountCredential(initializer.FromPrivateKey(privateKey));
service = new SheetsService(new BaseClientService.Initializer()
{
HttpClientInitializer = credential,
});
}
}
Part of my ReadFile code:
public async Task<string> ReadFile(string sheetName, string cellLocation) // for reading data only
{
// creates a string of location to write to
string whereToRead = sheetName + "!" + cellLocation;
SpreadsheetsResource.ValuesResource.GetRequest request = service.Spreadsheets.Values.Get(Secrets.spreadsheetID, whereToRead);
StringBuilder sb = new StringBuilder();
ValueRange response = await request.ExecuteAsync(); // run this on a separate thread as it takes long?
IList<IList<object>> values = response.Values;
On the phone, it executes the stringbuilder line, but not the executeasync() line.
Tried:
upgrade Unity version
change the min and target API levels
introduced keystore and project keys
introduced async incase it was a loading issue
change custom gradle template checkboxes
change read access on android sdk
update nuget installs of google apis
asking chatgpt for help
looking at various forums for similar issues
I am not running on an emulator, so no help with errors during run time. No errors in editor when built.
Expecting:
when installed on android device, the app to read/write from google sheet located in google drive
Requesting:
ideas to try to get this working! Thankyou :)

Android https post with hard coded URL and post data in Json format

Apollogies for a question that I can see has alot of hits however I can't find any recent answers. Given how fast android dev moves I thought I would ask a new question.
New to kotlin and android dev, one off app.
Using Android Studio & Kotlin - How to make an app that executes a HTTPS POST with hard coded URL and POST data in JSON format once the app is opened. No user action required other than opening the app. The app needs no UI.

Found what I was looking for in ktor: https://ktor.io/docs/request.html#body
import io.ktor.client.request.*
import io.ktor.client.statement.*
import io.ktor.http.*
val response: HttpResponse = client.post("http://localhost:8080/post") {
setBody("Body content")
}
val response: HttpResponse = client.post("http://localhost:8080/customer") {
contentType(ContentType.Application.Json)
setBody(Customer(3, "Jet", "Brains"))
}

Xamarin SqlServer cant get a connection

I'm building an app with the Entity Framework on Xamarin that lets me compare some data. But when I start my "fetchdata" function, I receive the Error:
System.Data.SqlClient.SqlException (0x80131904): Snix_Connect (provider: SNI_PN7, error: 35 - SNI_ERROR_35)Snix_Connect (provider: SNI_PN7, error: 35 - SNI_ERROR_35)
I see many posts about Xamarin / Android & that it is not possible to get a connection to a SQL Server. Is there any way to fetch data from a SQL Server with .NET Core on Xamarin?

This is the string I put into SQL_Class folder with Sql_Common.cs
Fill up the brace brackets with actual parameters (removing the brace brakets too).
public static string SQL_connection_string = #"data source={server_address};initial catalog={database_name};user id={user_id};password={password};Connect Timeout={seconds}";
Then I access whenever I need it from any xamarin code just like we use in our asp.net c#
This works for me on my app without any issues.
using (SqlConnection Sql_Connection = new SqlConnection(Sql_Common.saralEHR_connection_string))
But as #Jason mentioned in his first reply, I too would get once again check the security part. I fexperienced before publishing Package to Google Play, they encrypt the App files with Hash Key Code and then only it gets upload to server

Yes it is possible (HuurrAYY!):
Im new in .net core, c# and so on and for me it was a hell of a work to get it working..
So here for the other noobs who are seeking for Help:
Guide´s i used:
Building Android Apps with Entity Framework
https://medium.com/#yostane/data-persistence-in-xamarin-using-entity-framework-core-e3a58bdee9d1
https://blog.xamarin.com/building-android-apps-entity-framework/
Scaffolding
https://cmatskas.com/scaffolding-dbcontext-and-models-with-entityframework-core-2-0-and-the-cli/
How i did it:
Build your normal Xamarin app.
create new .net solution like in the tutorials (DONT WRITE YOUR Entity Framework CLASSES)
create a third solution what has to be a .net core console application
Scaffold your DB in your CONSOLE application move all created classes & folders in your "xamarin .net" solution & change the namespaces
Ready to Go!
Side Node: NuGets you need in every solution:
Microsoft.EntityFrameworkCore
Microsoft.EntityFrameworkCore.SqlServer
[EDIT: NuGets you need in every solution]

I am doing this way (working snippet):
string connectionString = #"data source={server};initial catalog={database};user id={user};password={password};Connect Timeout=10";
string databaseTable = "{table name}";
string selectQuery = String.Format("SELECT count(*) as Orders FROM {0}", databaseTable);
try
{
using (SqlConnection connection = new SqlConnection(connectionString))
{
//open connection
connection.Open();
SqlCommand command = new SqlCommand(selectQuery, connection);
command.Connection = connection;
command.CommandText = selectQuery;
var result = command.ExecuteScalar().ToString();
//check if there is result
if(result != null)
{
OrdersLabel.Text = result;
}
}
}
catch (Exception ex)
{
OrdersLabel.Text = ex.Message;
}
It is working fine, but API call more elegant.
I hope it helps.

How can I implement SSL Certificate Pinning while using React Native

I need to implement SSL Certificate Pinning in my react native application.
I know very little about SSL/TLS let alone pinning.
I am also not a native mobile developer, though I know Java and learned Objective-C on this project enough to get around.
I started searching for how to execute this task.
Doesn't React Native already implement this?
No, My initial search lead me to this proposal which has received no activity since August 2nd 2016.
From it I learned that react-native uses OkHttp which does support Pinning, but I wouldn't be able to pull it off from Javascript, which is not really a requirement but a plus.
Implement it in Javascript.
While react seems like it uses the nodejs runtime, it is more like a browser than node, meaning it does not support all native modules, specifically the https module, for which I had implemented certificate pinning following this article. Thus could not carry it into react native.
I tried using rn-nodeify but the modules didn't work. This has been true since RN 0.33 to RN 0.35 which I'm currently on.
Implement using phonegap plugin
I thought of using a phongape-plugin however since I have a dependency on libraries that require react 0.32+ I can't use react-native-cordova-plugin
Just do it natively
While I'm not a native app developer I can always take a crack at it, only a matter of time.
Android has certificate pinning
I learned that android supports SSL Pinning however was unsuccessful as it seems that this approach does not work Prior to Android 7. As well as only working for android.
The bottom line
I have exhausted several directions and will continue to pursue more native implementation, maybe figure out how to configure OkHttp and RNNetworking then maybe bridging back to react-native.
But is there already any implementations or guide for IOS and android?

After exhausting the current spectrum of available options from Javascript I decided to simply implement certificate pinning natively it all seems so simple now that I'm done.
Skip to headers titled Android Solution and IOS Solution if you don't want to read through the process of reaching the solution.
Android
Following Kudo's recommendation I thought out to implement pinning using okhttp3.
client = new OkHttpClient.Builder()
.certificatePinner(new CertificatePinner.Builder()
.add("publicobject.com", "sha1/DmxUShsZuNiqPQsX2Oi9uv2sCnw=")
.add("publicobject.com", "sha1/SXxoaOSEzPC6BgGmxAt/EAcsajw=")
.add("publicobject.com", "sha1/blhOM3W9V/bVQhsWAcLYwPU6n24=")
.add("publicobject.com", "sha1/T5x9IXmcrQ7YuQxXnxoCmeeQ84c=")
.build())
.build();
I first started by learning how to create a native android bridge with react nativecreating a toast module. I then extended it with a method for sending a simple request
#ReactMethod
public void showURL(String url, int duration) {
try {
Request request = new Request.Builder()
.url(url)
.build();
Response response = client.newCall(request).execute();
Toast.makeText(getReactApplicationContext(), response.body().string(), duration).show();
} catch (IOException e) {
Toast.makeText(getReactApplicationContext(), e.getMessage(), Toast.LENGTH_SHORT).show();
}
}
Succeeding in sending a request I then turned to sending a request pinned.
I used these packages in my file
import com.facebook.react.bridge.NativeModule;
import com.facebook.react.bridge.ReactApplicationContext;
import com.facebook.react.bridge.ReactContext;
import com.facebook.react.bridge.ReactContextBaseJavaModule;
import com.facebook.react.bridge.ReactMethod;
import com.facebook.react.bridge.Callback;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.Response;
import okhttp3.CertificatePinner;
import java.io.IOException;
import java.util.Map;
import java.util.HashMap;
Kudo's approach wasn't clear on where I would get the public keys or how to generate them. luckily okhttp3 docs in addition to providing a clear demonstration of how to use the CertificatePinner stated that to get the public keys all I would need to do is send a request with an incorrect pin, and the correct pins will appear in the error message.
After taking a moment to realise that OkHttpClent.Builder() can be chained and I can include the CertificatePinner before the build, unlike the misleading example in Kudo's proposal (probably and older version) I came up with this method.
#ReactMethod
public void getKeyChainForHost(String hostname, Callback errorCallbackContainingCorrectKeys,
Callback successCallback) {
try {
CertificatePinner certificatePinner = new CertificatePinner.Builder()
.add(hostname, "sha256/AAAAAAAAAAAAAAAAAAAAAAAAAAA=")
.build();
OkHttpClient client = (new OkHttpClient.Builder()).certificatePinner(certificatePinner).build();
Request request = new Request.Builder()
.url("https://" + hostname)
.build();
Response response =client.newCall(request).execute();
successCallback.invoke(response.body().string());
} catch (Exception e) {
errorCallbackContainingCorrectKeys.invoke(e.getMessage());
}
}
Then replacing the public keychains I got in the error yielded back the page's body, indicating I had made a successful request, I change one letter of the key to make sure it was working and I knew I was on track.
I finally had this method in my ToastModule.java file
#ReactMethod
public void getKeyChainForHost(String hostname, Callback errorCallbackContainingCorrectKeys,
Callback successCallback) {
try {
CertificatePinner certificatePinner = new CertificatePinner.Builder()
.add(hostname, "sha256/+Jg+cke8HLJNzDJB4qc1Aus14rNb6o+N3IrsZgZKXNQ=")
.add(hostname, "sha256/aR6DUqN8qK4HQGhBpcDLVnkRAvOHH1behpQUU1Xl7fE=")
.add(hostname, "sha256/HXXQgxueCIU5TTLHob/bPbwcKOKw6DkfsTWYHbxbqTY=")
.build();
OkHttpClient client = (new OkHttpClient.Builder()).certificatePinner(certificatePinner).build();
Request request = new Request.Builder()
.url("https://" + hostname)
.build();
Response response =client.newCall(request).execute();
successCallback.invoke(response.body().string());
} catch (Exception e) {
errorCallbackContainingCorrectKeys.invoke(e.getMessage());
}
}
Android Solution Extending React Native's OkHttpClient
Having figured out how to send pinned http request was good, now I can use the method I created, but ideally I thought it would be best to extend the existing client, so as to immediately gain the benefit of implementing.
This solution is valid as of RN0.35 and I don't know how it will fair in the future.
While looking into ways of extending the OkHttpClient for RN I came across this article explaining how to add TLS 1.2 support through replacing the SSLSocketFactory.
reading it I learned react uses an OkHttpClientProvider for creating the OkHttpClient instance used by the XMLHttpRequest Object and therefore if we replace that instance we would apply pinning to all the app.
I added a file called OkHttpCertPin.java to my android/app/src/main/java/com/dreidev folder
package com.dreidev;
import android.util.Log;
import com.facebook.react.modules.network.OkHttpClientProvider;
import com.facebook.react.modules.network.ReactCookieJarContainer;
import java.util.concurrent.TimeUnit;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.Response;
import okhttp3.CertificatePinner;
public class OkHttpCertPin {
private static String hostname = "*.efghermes.com";
private static final String TAG = "OkHttpCertPin";
public static OkHttpClient extend(OkHttpClient currentClient){
try {
CertificatePinner certificatePinner = new CertificatePinner.Builder()
.add(hostname, "sha256/+Jg+cke8HLJNzDJB4qc1Aus14rNb6o+N3IrsZgZKXNQ=")
.add(hostname, "sha256/aR6DUqN8qK4HQGhBpcDLVnkRAvOHH1behpQUU1Xl7fE=")
.add(hostname, "sha256/HXXQgxueCIU5TTLHob/bPbwcKOKw6DkfsTWYHbxbqTY=")
.build();
Log.d(TAG, "extending client");
return currentClient.newBuilder().certificatePinner(certificatePinner).build();
} catch (Exception e) {
Log.e(TAG, e.getMessage());
}
return currentClient;
}
}
This package has a method extend which takes an existing OkHttpClient and rebuilds it adding the certificatePinner and returns the newly built instance.
I then modified my MainActivity.java file following this answer's advice by adding the following methods
.
.
.
import com.facebook.react.ReactActivity;
import android.os.Bundle;
import com.dreidev.OkHttpCertPin;
import com.facebook.react.modules.network.OkHttpClientProvider;
import okhttp3.OkHttpClient;
public class MainActivity extends ReactActivity {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
rebuildOkHtttp();
}
private void rebuildOkHtttp() {
OkHttpClient currentClient = OkHttpClientProvider.getOkHttpClient();
OkHttpClient replacementClient = OkHttpCertPin.extend(currentClient);
OkHttpClientProvider.replaceOkHttpClient(replacementClient);
}
.
.
.
This solution was carried out in favor of completely reimplementing the OkHttpClientProvider createClient method, as inspecting the provider I realized that the master version had implemented TLS 1.2 support but was not yet an available option for me to use, and so rebuilding was found to be the best means of extending the client. I'm wondering how this approach will fair as I upgrade but for now it works well.
Update It seems that starting 0.43 this trick no longer works. For timebound reasons I will freeze my project at 0.42 for now, until the reason for why rebuilding stopped working is clear.
Solution IOS
For IOS I had thought I would need to follow a similar method, again starting with Kudo's proposal as my lead.
Inspecting the RCTNetwork module I learned that NSURLConnection was used, so instead of trying to create a completely new module with AFNetworking as suggested in the proposal I discovered TrustKit
following its Getting Started Guide I simply added
pod 'TrustKit'
to my podfile and ran pod install
the GettingStartedGuide explained how I can configure this pod from my pList.file but preferring to use code than configuration files I added the following lines to my AppDelegate.m file
.
.
.
#import <TrustKit/TrustKit.h>
.
.
.
#implementation AppDelegate
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
// Initialize TrustKit
NSDictionary *trustKitConfig =
#{
// Auto-swizzle NSURLSession delegates to add pinning validation
kTSKSwizzleNetworkDelegates: #YES,
kTSKPinnedDomains: #{
// Pin invalid SPKI hashes to *.yahoo.com to demonstrate pinning failures
#"efghermes.com" : #{
kTSKEnforcePinning:#YES,
kTSKIncludeSubdomains:#YES,
kTSKPublicKeyAlgorithms : #[kTSKAlgorithmRsa2048],
// Wrong SPKI hashes to demonstrate pinning failure
kTSKPublicKeyHashes : #[
#"+Jg+cke8HLJNzDJB4qc1Aus14rNb6o+N3IrsZgZKXNQ=",
#"aR6DUqN8qK4HQGhBpcDLVnkRAvOHH1behpQUU1Xl7fE=",
#"HXXQgxueCIU5TTLHob/bPbwcKOKw6DkfsTWYHbxbqTY="
],
// Send reports for pinning failures
// Email info#datatheorem.com if you need a free dashboard to see your App's reports
kTSKReportUris: #[#"https://overmind.datatheorem.com/trustkit/report"]
},
}
};
[TrustKit initializeWithConfiguration:trustKitConfig];
.
.
.
I got the public key hashes from my android implementation and it just worked (the version of TrustKit I received in my pods is 1.3.2)
I was glad IOS turned out to be a breath
As a side note TrustKit warned that it's Auto-swizzle won't work if the NSURLSession and Connection are already swizzled. that said it seems to be working well so far.
Conclusion
This answer presents the solution for both Android and IOS, given I was able to implement this in native code.
One possible improvement may be to implement a common platform module where setting public keys and configuring the Network providers of both android and IOS can be managed in javascript.
Kudo's proposal mentioned simply adding the public keys to the js bundle may however expose a vulnerability, where somehow the bundle file can be replaced.
I don't know how that attack vector can function, but certainly the extra step of signing the bundle.js as proposed may protect the js bundle.
Another approach may be to simply encode the js bundle into a 64 bit string and include it in the native code directly as mentioned in this issue's conversation. This approach has the benefit of obfuscating as well hardwiring the js bundle into the app, making it inaccessible for attackers or so I think.
If you read this far I hope I enlightened you on your quest for fixing your bug and wish you enjoy a sunny day.

You can use this lib https://github.com/nlt2390/react-native-pinning-ssl
It verifies SSL connection using SHA1 keys, not certificates.

Endpoint.Builder missing for generated cloud endpoint

I'm attempting to follow the example tutorial at https://developers.google.com/eclipse/docs/endpoints-addentities and I'm stuck figuring out how to get the GameEndpoint.Builder class to generate within Eclipse.
After following this and generating the cloud endpoints as described, I have a GameEndpoint class created, but there is no GameEndpoint.Builder class. So obviously I have this error
GameEndpoint.Builder cannot be resolved to a type
I'm stumped at this point. How do I generate the GameEndpoint.Builder class within Eclipse, or what would prevent it?
Code
public class NewGameTask extends AsyncTask<Context, Integer, Long> {
protected Long doInBackground(Context... contexts) {
GameEndpoint.Builder endpointBuilder = new GameEndpoint.Builder(
AndroidHttp.newCompatibleTransport(), new JacksonFactory(),
new HttpRequestInitializer() {
public void initialize(HttpRequest httpRequest) {
}
});
GameEndpoint endpoint = CloudEndpointUtils.updateBuilder(
endpointBuilder).build();
try {
Game game = new Game();
game.setStart(Calendar.getInstance());
Game result = endpoint.insertGame(game);
} catch (IOException e) {
e.printStackTrace();
}
return (long) 0;
}
}

I figured out my issue after watching this video from Google I/O 2013 which is using Android Studio, but it was the same thing as Eclipse mostly.
My mistake in following https://developers.google.com/eclipse/docs/endpoints-addentities was that you need to put your entity class into the MyApp-AppEngine project and NOT your MyApp project.
That was the source of confusion. In case it helps those in the future, here is a short breakdown of what I did.
Put the Entity class you want to add to App Engine into your MyApp-AppEngine project.
Right click your class and go to Google > Generate Cloud Endpoint Client Library
Right click your MyApp-AppEngine project and go to Google > Generate Cloud Enpoint Client Library
New references will be made in your MyApp project which you reference in your project for usage.

Note This answer is based on Android Studio, but am sure it's pretty much the same as Eclipse.
I also had this issue but later found the cause.Turns out I was importing the Endpoint class I generated instead of the endpoint Api package. Let me be clear.When you add the endpoint module to your project, you get the MyBean and MyEndpoint classes in the endpoint package. If you take a look at the guide to connecting your client to your backend, the EndpointsAsyncTask class uses:
private static MyApi myApiService = null;
Note how it uses MyApi instead of MyBean Now I was wondering where it got that from but I just have to take a look at my backend libraries:
The library marked 1 is the library first added to your project when you follow the guide previously mentioned. When I added a new class Student and autogenerated the cloud endpoint class, the second library was also added.
Long, boring story short; It is this library you should be importing and not the class.
import com.package-name.backend.studentApi.StudentApi;
and then using:
private static StudentApi myApiService = null;
...
StudentApi.Builder builder = new StudentApi.Builder(...)
instead of:
import com.package-name.backend.StudentEndpoint;
...
private static StudentEndpoint myApiService = null;
StudentEndpoint.Builder builder = new StudentEndpoint.Builder(...)

I got the same problem in Android Studio. I generated my Endpoint class from my entity java bean but when creating the AsyncTask, now way to get the Builder.
Actually (if I take a Game java bean like you) the Builder is not depending on the GameEndPoint but on the generated GameApi class.
In other words, I had to add these two imports in the AsyncTask class:
import com.examplepackage.backend.gameApi.GameApi;
import com.examplepackage.backend.gameApi.model.Game;
while the Game java bean that you wrote and the generated GameEndpoint are under package com.examplepackage.backend