Upload Block Blob to Azure Storage via SDK - Server failed to authenticate the request

Question

From my ASP.Net Core app, I try to upload a block blob to Azure Storage Service. I took the example from Microsoft:

    var accountName = "accountname";
    var accountKey = "key";
    //var storageAccount = new CloudStorageAccount(new StorageCredentials(accountName, accountKey), true);
    CloudStorageAccount storageAccount = CloudStorageAccount.Parse("myconnectionstring");

    // Create the blob client.
    CloudBlobClient blobClient = storageAccount.CreateCloudBlobClient();

    // Retrieve reference to a previously created container.
    CloudBlobContainer container = blobClient.GetContainerReference(Container);

    // Retrieve reference to a blob named "test".
    CloudBlockBlob blockBlob = container.GetBlockBlobReference("test");

    // Create or overwrite the "test" blob with contents from a local file.
    using (var fileStream = System.IO.File.OpenRead(@"E:\Drone\N_01004619000008.jpg"))
    {
        await blockBlob.UploadFromStreamAsync(fileStream);
    }

This results in the following error:

StorageException: Server failed to authenticate the request. Make sure the value of Authorization header is formed correctly including the signature.

Using fiddler I could also see this additional error info:

The MAC signature found in the HTTP request 'blankedOutKey' is not the same as any computed signature. Server used following string to sign: 'PUT'

...whereas the 'blankedOutKey' is not the key I actually used for authentication. Not sure where it comes from. As you can see in my Code Snippet, I tried both using my accountName and accountKey as well as the ConnectionString.

What am I doing wrong?

Edit: I tried this here: https://github.com/Azure-Samples/storage-dotnet-sas-getting-started

With the exact same connection string, it worked in the solution from github but when I took over the complete code to my ASP.Net Core 1.1 app, I again faced the issue mentioned. So I double checked the differences. It turns out that the project from github uses the 6.2.0 version of "Microsoft.WindowsAzure.Storage" while my ASP.Net Core app uses the 8.1.3 version.

Furthermore, I double checked the HTTP requests from both solutions in fiddler. Here is the one from the older SDK which works:

User-Agent: WA-Storage/6.2.0 (.NET CLR 4.0.30319.42000; Win32NT 6.2.9200.0) x-ms-version: 2015-04-05 x-ms-client-request-id: c1aea889-73f8-4b6b-9a1f-2f2f9e021846 x-ms-date: Sun, 04 Jun 2017 12:23:37 GMT Authorization: SharedKey mystoragename:F5yhOOh2taUBfUE+3wii1cYb0D7L+jZGVfs1xTgTme0= Host: mystoragename.blob.core.windows.net Content-Length: 0

The request submitted through the newer SDK which fails:

Connection: Keep-Alive Authorization: SharedKey mystoragenamee:IxtXuZFIcPjeKnqjktxvfcQMRLkfHM5SVN9zvQZmBJc= User-Agent: Azure-Storage/8.1.3 (.NET Core) x-ms-client-request-id: d890d2e0-07af-4695-af1f-8020c9476774 x-ms-version: 2016-05-31 x-ms-date: Sun, 04 Jun 2017 12:24:49 GMT x-ms-request-root-id: 428e8e6279f1ff9d-4237b4f7 x-ms-request-id: |428e8e6279f1ff9d-4237b4f7.1. Request-Id: |428e8e6279f1ff9d-4237b4f7.1. Content-Length: 0 Host: mystoragename.blob.core.windows.net

Tom Sun - MSFT Tom Sun - MSFT · Accepted Answer · 2017-06-05T05:48:28

The MAC signature found in the HTTP request 'blankedOutKey' is not the same as any computed signature. Server used following string to sign: 'PUT'

According to the exception, it seems that construct authorization is not correct. But you are using Azure storage SDK. It seems that exception happened in the other code.

Please have a try to create a project and try it again. I can't repro it with you mentioned code in .net core Asp.net project. It works correctly on my side.

The following is my detail steps:

1.Create a .net core project.

2.Add the Azure storage SDK

3.Create the function with you mentioned code.

 public async Task UploadBlobAsync()
        {
            const string myconnctionstring = "DefaultEndpointsProtocol=https;AccountName=accountname;AccountKey=yourkey;EndpointSuffix=core.windows.net";
            //var storageAccount = new CloudStorageAccount(new StorageCredentials(accountName, accountKey), true);
            CloudStorageAccount storageAccount = CloudStorageAccount.Parse(myconnctionstring);

            // Create the blob client.
            CloudBlobClient blobClient = storageAccount.CreateCloudBlobClient();

            // Retrieve reference to a previously created container.
            CloudBlobContainer container = blobClient.GetContainerReference("test");

            container.CreateIfNotExistsAsync().Wait();
            // Retrieve reference to a blob named "test".
            CloudBlockBlob blockBlob = container.GetBlockBlobReference("test.jpg");

            // Create or overwrite the "test" blob with contents from a local file.
            using (var fileStream = System.IO.File.OpenRead(@"file path"))
            {
                await blockBlob.UploadFromStreamAsync(fileStream);
            }
        }

4.Call the function

public IActionResult About()
        {
            ViewData["Message"] = "upload blob.";
            UploadBlobAsync().Wait();
            return View();
        }

5.Run the project and visit it about page, it works correctly.

6.I also catch it with fiddler.

Upload Block Blob to Azure Storage via SDK - Server failed to authenticate the request

2 Answers