/// <summary>
/// Verification device information required for positive submissions
/// </summary>
/// <returns>Device Verification Payload</returns>
private static async Task <string> GetSafetyNetAttestationAsync(byte[] nonce)
{
using var client = SafetyNetClass.GetClient(Android.App.Application.Context);
using var response = await client.AttestAsync(nonce, AppSettings.Instance.AndroidSafetyNetApiKey);
return(response.JwsResult);
}
public async System.Threading.Tasks.Task AttestateAsync(Activity activity)
{
try
{
var api = RestService.For <ApiService>("https://devenir.andrewkir.ru");
JSONObject obj = new JSONObject();
timestamp = DateTime.Now.Ticks.ToString();
device_id = Secure.GetString(activity.ContentResolver, Secure.AndroidId);
obj.Put("timestamp", timestamp);
obj.Put("device_id", device_id);
var response = await api.GetNonce(obj.ToString());
if (response == null)
{
AttestationResultEvent?.Invoke(false, activity.GetString(Resource.String.noInternetException));
return;
}
if (response.IsSuccessStatusCode)
{
string nonce = response.Content;
if (GoogleApiAvailability.Instance.IsGooglePlayServicesAvailable(Application.Context) == ConnectionResult.Success)
{
// The SafetyNet Attestation API is available.
SafetyNetClient client = SafetyNetClass.GetClient(activity);
var task = client.Attest(Encoding.ASCII.GetBytes(nonce), activity.Resources.GetString(Resource.String.api_safetyNetKey))
.AddOnSuccessListener(activity, new OnSuccessListener(activity, timestamp, this))
.AddOnFailureListener(activity, new OnFailureListener(activity, this));
}
else
{
// Prompt user to update Google Play services
AttestationResultEvent?.Invoke(false, activity.GetString(Resource.String.attestationGooglePlayException));
}
return;
}
else
{
AttestationResultEvent?.Invoke(false, activity.GetString(Resource.String.serverException) + $"failed with nonce");
return;
}
}
catch (HttpRequestException ex)
{
AttestationResultEvent?.Invoke(false, activity.GetString(Resource.String.serverException) + $"https exception {ex}");
}
catch (Exception ex)
{
AttestationResultEvent?.Invoke(false, activity.GetString(Resource.String.unexpectedException));
}
}
protected override void OnCreate(Bundle bundle)
{
base.OnCreate(bundle);
// Set our view from the "main" layout resource
SetContentView(Resource.Layout.Main);
buttonCheck = FindViewById <Button> (Resource.Id.buttonCheck);
buttonVerify = FindViewById <Button> (Resource.Id.buttonVerify);
buttonVerify.Enabled = false;
googleApiClient = new GoogleApiClient.Builder(this)
.EnableAutoManage(this, this)
.AddApi(SafetyNetClass.API)
.Build();
buttonCheck.Click += async delegate {
var api = SafetyNetClass.GetClient(this);
var nonce = Nonce.Generate(); // Should be at least 16 bytes in length.
var r = await api.AttestAsync(nonce, DEVELOPERS_CONSOLE_API_KEY);
if (r != null && !string.IsNullOrEmpty(r.JwsResult))
{
// Store for future verification with google servers
attestationResponse = r;
// Get the JSON from the JWS result by decoding
var decodedResult = r.DecodeJwsResult(nonce);
string error = null;
// Try and verify the body of the response
if (VerifyAttestResponse(decodedResult, nonce, out error))
{
Toast.MakeText(this, "Compatibility Passed!", ToastLength.Long).Show();
buttonVerify.Enabled = true;
}
else
{
Toast.MakeText(this, "Compatibility Failed: " + error, ToastLength.Long).Show();
}
}
else
{
// Error
Toast.MakeText(this, "Failed to Check Compatibility", ToastLength.Long).Show();
}
};
buttonVerify.Click += async delegate {
// Validate the JWS response with Google to ensure it came from them
var valid = await attestationResponse.ValidateWithGoogle(DEVELOPERS_CONSOLE_API_KEY);
if (valid)
{
Toast.MakeText(this, "Successfully validated response with Google!", ToastLength.Short).Show();
}
else
{
Toast.MakeText(this, "Failed response validation with Google!", ToastLength.Short).Show();
}
};
}
