Good Sample for AWS S3 file transfer Xamarin forms? - xamarin.forms

Is there is any best sample for xamarin aws s3 server file transfer? I had tried the sample but it is working in native android, not working in xamarin forms. could someone please guide me. Thanks
Any help will be greatly appretiated.
if (file == null)
{
Toast.MakeText(this, "No file to upload", ToastLength.Short).Show();
return;
}
var S3Client = S3Utils.S3Client;
try
{
var response = await S3Client.PutObjectAsync(new PutObjectRequest()
{
BucketName = Constants.BUCKET_NAME.ToLowerInvariant(),
FilePath = file.AbsolutePath,
Key = file.Name
});
Toast.MakeText(this, "File uploaded to S3 Bucket", ToastLength.Long).Show();
}
catch (AmazonS3Exception s3Exception)
{
Toast.MakeText(this, "Upload failed, check logs for more information", ToastLength.Long).Show();
System.Console.WriteLine(s3Exception.StackTrace);
}
}

Well, I think you should go through their documentation for Xamarin and .Net
In the Setting Up the AWS Mobile SDK for .NET and Xamarin, they have given their own samples to refer to!!
Following are the links for each service that they provide for Xamarin
Cognito Identity
Cognito Sync
Dynamo DB
Mobile Analytics
S3
SNS
Also when you check the Using the S3 Transfer utility docs
They have everything you need there to configure your Forms project using Dependency services.
Do not forget to read the API usage for S3 before you start working with the same

Related

Azure AD Application Add User to Active Directory using Client Credentials

I am trying to add a user to an application Active Directory but with little success. I am using the GraphServiceClient with.Net Core
The documentation here says I need these permissions
Azure AD Graph Client Beta Docs
Application Directory.ReadWrite.All
But I cannot find where in the Azure Portal I can assign this permission.
The code is above, the GraphServiceClient is in beta at the moment and this is not part of the API yet, so I am calling the request manually.
Below is my code for authentication, I am using my applications client secret which is set against the application in the AD. I can read directory data fine.
public async Task AuthenticateRequestAsync(HttpRequestMessage request)
{
try
{
if (null == _configuration)
{
throw new InvalidOperationException("Azure AD Configuration is not set");
}
var authContext = new AuthenticationContext(
$"{_configuration.Instance}/{_configuration.Domain}", false);
var credentials = new ClientCredential(_configuration.ClientId, _configuration.ClientSecret);
var authResult =
await authContext.AcquireTokenAsync("https://graph.microsoft.com/", credentials);
request.Headers.Add("Authorization", "Bearer " + authResult.AccessToken);
}
catch (Exception ex)
{
_logger.Error("Authentication Provider, unable to get token", ex);
}
}
Update - After checking with Rohit's advice, you can see I have the permissions set. But notice they are all in blue with the ticks next to them! I have changed and saved, you can see the save button is disabled. I have clicked Grant Permissions. Is this relevant?
But I cannot find where in the Azure Portal I can assign this
permission.
In Azure portal navigate to Azure Active Directory > App Registrations > Your specific app > Settings > Required Permissions
Click on Add and Select Microsoft Graph
Now, in the Application Permissions section, check "Read and write directory data"
Once you're done, do "Grant Permissions" for Admin consent, as this permission needs it.

Issue with jwt-bearer on-behalf-of grant in Azure AD

So I have an Angular app that uses the adal-angular library to authenticate with an ASP.NET Core 2.0 Web API. The API then uses on-behalf-of flow to authenticate with another API using the users token like this MS article https://learn.microsoft.com/en-us/azure/active-directory/develop/active-directory-protocols-oauth-on-behalf-of.
The issue I have is this is working fine in the DEV environment but I have now deployed a TST environment with separate App Registrations and I am receiving the following exception when I try and request the token using on-behalf-of
AADSTS240002: Input id_token cannot be used as 'urn:ietf:params:oauth:grant-type:jwt-bearer' grant.
The code I am using to request the token
public async Task<string> AcquireTokenAsync(string resource)
{
try
{
string accessToken = await _httpContextAccessor.HttpContext.GetTokenAsync(AuthenticationConstants.AccessToken);
var credentials = new ClientCredential(_azureOptions.ClientId, _azureOptions.ClientSecret);
var authContext = new AuthenticationContext($"{_azureOptions.Instance}{_azureOptions.TenantId}")
{
ExtendedLifeTimeEnabled = true
};
// On-behalf-of auth token request call
var authResult = await authContext.AcquireTokenAsync(
resource,
credentials,
new UserAssertion(accessToken));
return authResult.AccessToken;
}
catch (AdalServiceException asex)
{
_logger.LogError(asex, $"Instance: {_azureOptions.Instance} Tenant: {_azureOptions.TenantId} ClientId: {_azureOptions.ClientId}");
throw;
}
catch (System.Exception ex)
{
_logger.LogError(ex, ex.Message);
throw;
}
}
And I have used Fiddler and it looks like all the correct parameters are being passed.
Any help would be very much appreciated. I have set knownClientApplications on the second API and I have granted permissions on the Angular backend API to the second API.
For me, I got it to work by changing BOTH of the following to true:
oauth2AllowImplicitFlow
oauth2AllowIdTokenImplicitFlow
See here for more information.
According to your question and the error, it should be caused by that you angular app is not a Native(public) app.
For using this OBO flow with this Grant type, your client must be a public client not credential client.
If you want to register your client as a WebApp/API, you can refer to this Implementation:
Hope this helps!
Update
According to OP's comment, he/she got it working by changing oauth2AllowImplicitFlow from false to true.
We had this problem last week with one Azure Service Registration and not another. A review found that the token didn't return an AIO being returned. It turns out that the registration had redirects with wildcards (e.g., https://*.ngrok.io) and this is incompatible with the AcquireTokenOnBehalfOf function. I'm posting this here so a future person, probably me, will find it.
I was having problems even when oauth2AllowImplicitFlow and oauth2AllowIdTokenImplicitFlow were set to true. One of my Reply URLs had a wildcard in it. When the wildcard was removed, the issue was resolved.

Xamarin Forms Open URI with token

I am building an Xamarin Forms PCL app and getting authenticated successfully with MSAL. My REST calls to graph API are all successful.
What I am trying to do is to open outlook or yammer or calendar in the browser using the token, i.e. without asking the users the re-authenticate.
Device.openUri always sends the users to an auth page, which makes sense since i am not sending the token with it.
Is this possible at all? If so, How can it be done?
thanks in advance !
Please add permission (to Yammer for example) on your App registration in Azure.
then define your array of scope as following
string[] Scopes = { "User.Read", "https://api.yammer.com/user_impersonation" };
then initiate your PublicClientApplication (PCA)
PCA = PublicClientApplicationBuilder.Create(ClientId).WithRedirectUri(ReturnUrl).Build();
after that as per the example from MSAL Team here you will need to add this code in your login button
try
{
IAccount firstAccount = accounts.FirstOrDefault();
authResult = await App.PCA.AcquireTokenSilent(App.Scopes, firstAccount)
.ExecuteAsync();
/* display info*/
}
catch (MsalUiRequiredException ex)
{
try
{
authResult = await App.PCA.AcquireTokenInteractive(App.Scopes, App.ParentWindow)
.ExecuteAsync();
/* display info*/
}
}
Now the Token you will get will work with Yammer as well
Hope this would help

Is Azure Function to Function authentication with MSI supported

I created 2 Azure Function Apps, both setup with Authentication/Authorization so an AD App was created for both. I would like to setup AD Auth from one Function to the other using MSI. I setup the client Function with Managed Service Identity using an ARM template. I created a simple test function to get the access token and it returns: Microsoft.Azure.Services.AppAuthentication: Token response is not in the expected format.
try {
var azureServiceTokenProvider = new AzureServiceTokenProvider();
string accessToken = await azureServiceTokenProvider.GetAccessTokenAsync("https://myapp-registration-westus-dev.azurewebsites.net/");
log.Info($"Access Token: {accessToken}");
return req.CreateResponse(new {token = accessToken});
}
catch(Exception ex) {
log.Error("Error", ex);
throw;
}
Yes, there is a way to do this. I'll explain at a high level, and then add an item to the MSI documentation backlog to write a proper tutorial for this.
What you want to do is follow this Azure AD authentication sample, but only configure and implement the parts for the TodoListService: https://github.com/Azure-Samples/active-directory-dotnet-daemon.
The role of the TodoListDaemon will be played by a Managed Service Identity instead. So you don't need to register the TodoListDaemon app in Azure AD as instructed in the readme. Just enable MSI on your VM/App Service/Function.
In your code client side code, when you make the call to MSI (on a VM or in a Function or App Service), supply the TodoListService's AppID URI as the resource parameter. MSI will fetch a token for that audience for you.
The code in the TodoListService example will show you how to validate that token when you receive it.
So essentially, what you want to do is register an App in Azure AD, give it an AppID URI, and use that AppID URI as the resource parameter when you make the call to MSI. Then validate the token you receive at your service/receiving side.
Please check that the resource id used "https://myapp-registration-westus-dev.azurewebsites.net/" is accurate. I followed steps here to setup Azure AD authentication, and used the same code as you, and was able to get a token.
https://learn.microsoft.com/en-us/azure/app-service/app-service-mobile-how-to-configure-active-directory-authentication
You can also run this code to check the exact error returned by MSI. Do post the error if it does not help resolve the issue.
HttpClient client = new HttpClient();
client.DefaultRequestHeaders.Add("Secret", Environment.GetEnvironmentVariable("MSI_SECRET"));
var response = await client.GetAsync(String.Format("{0}/?resource={1}&api-version={2}", Environment.GetEnvironmentVariable("MSI_ENDPOINT"), "https://myapp-registration-westus-dev.azurewebsites.net/", "2017-09-01"));
string msiResponse = await response.Content.ReadAsStringAsync().ConfigureAwait(false);
log.Info($"MSI Response: {msiResponse}");
Update:-
This project.json file and run.csx file work for me. Note: The project.json refers to .NET 4.6, and as per Azure Functions documentation (link in comments), .NET 4.6 is the only supported version as of now. You do not need to upload the referenced assembly again. Most probably, incorrect manual upload of netstandard assembly, instead of net452 is causing your issue.
Only the .NET Framework 4.6 is supported, so make sure that your
project.json file specifies net46 as shown here. When you upload a
project.json file, the runtime gets the packages and automatically
adds references to the package assemblies. You don't need to add #r
"AssemblyName" directives. To use the types defined in the NuGet
packages, add the required using statements to your run.csx file.
project.json
{
"frameworks": {
"net46":{
"dependencies": {
"Microsoft.Azure.Services.AppAuthentication": "1.0.0-preview"
}
}
}
}
run.csx
using Microsoft.Azure.Services.AppAuthentication;
public static async Task<HttpResponseMessage> Run(HttpRequestMessage req, TraceWriter log)
{
try
{
var azureServiceTokenProvider = new AzureServiceTokenProvider();
string accessToken = await azureServiceTokenProvider.GetAccessTokenAsync("https://vault.azure.net/");
log.Info($"Access Token: {accessToken}");
return req.CreateResponse(new {token = accessToken});
}
catch(Exception ex)
{
log.Error("Error", ex);
throw;
}
}

Google Drive APi with clean WEB API 2

i wanted to use the Google Drive API along with a simple WEB API 2 - Project.
Somehow the GoogleWebAuthorizationBroker.cs is missing.
What i use:
Visual Studio 2013 Update 4
Empty Template with WEB API
My steps:
Creating the empty project including WEB API
building the project
updating packages via Nuget Packager
Install-Package Google.Apis.Drive.v2 (using this guide: https://developers.google.com/drive/web/quickstart/quickstart-cs)
Copy and Paste the code from the above link into a clean api-controller:
public IEnumerable<string> Get()
{
UserCredential credential = GoogleWebAuthorizationBroker.AuthorizeAsync(
new ClientSecrets
{
ClientId = "228492645857-5599mgcfnhrr74a7er1do1chpam4rnbt.apps.googleusercontent.com",
ClientSecret = "onoyJQaUazQK4VsKUjD63sDu",
},
new[] { DriveService.Scope.Drive },
"user",
CancellationToken.None).Result;
// Create the service.
var service = new DriveService(new BaseClientService.Initializer()
{
HttpClientInitializer = credential,
ApplicationName = "Drive API Sample",
});
File body = new File();
body.Title = "My document";
body.Description = "A test document";
body.MimeType = "text/plain";
byte[] byteArray = System.IO.File.ReadAllBytes(#"C:\Projects\VS\DataAnime\DataAnime\document.txt");
System.IO.MemoryStream stream = new System.IO.MemoryStream(byteArray);
FilesResource.InsertMediaUpload request = service.Files.Insert(body, stream, "text/plain");
request.Upload();
File file = request.ResponseBody;
return new string[] { file.Id, "value2" };
}
building
6.1 Error: GoogleWebAuthorizationBroker.cs is missing
6.2 Google says following error in browser:
That’s an error.
Error: redirect_uri_mismatch
Application: Project Default Service Account
You can email the developer of this application at: xxxx#gmail.com
The redirect URI in the request: http://example.com:63281/authorize/ did not match a registered
redirect URI.
http://example.com:63281/authorize/ was neither the url i am using for my project nor the url i registered in my developer console (this errorshowing-port is changeing everytime i run this project.
Has anyone an idea why is that?
No other sources helped fixing this weird issue.
I solved it by creating a new project on https://console.developers.google.com for a native software instead of a web-client project, even i am using a web client.
There is just one weird thing:
If i debug my code, it still says that GoogleWebAuthorizationBroker.cs is missing.
Without debugging i can do everything i want.
Thank you very much for your help.

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