Question

I’m trying to generate a Shared Access Signature for a blob (and use it) with the v2.0 of the Windows Azure Storage Client Library.
I started with this sample but it’s for v1.7, and transposing it to 2.0 gives a 404 error.

Here is my actual code :
Server side, to generate the SAS :

var myAccount = CloudStorageAccount.Parse(
                  ConfigurationManager.ConnectionStrings[
                              "AzureStorageConnectionString"].ConnectionString);
var myContainer = myAccount.CreateCloudBlobClient()
                                          .GetContainerReference(containerName);
myContainer.CreateIfNotExists();

string blobName = "Imports/" + DateTime.UtcNow.ToString("yyyy-MM-dd_HH-mm-ss") 
                             + ".zip";
var myBlob = myContainer.GetBlockBlobReference(blobName);
using (var stream = 
 new MemoryStream(System.Text.Encoding.UTF8.GetBytes("Hey, I'm empty for now.")))
{
    myBlob.UploadFromStream(stream);
}

var sharedAccesSignature = myBlob.GetSharedAccessSignature(
                 new Microsoft.WindowsAzure.Storage.Blob.SharedAccessBlobPolicy()
{
   Permissions = 
       Microsoft.WindowsAzure.Storage.Blob.SharedAccessBlobPermissions.Write 
       | Microsoft.WindowsAzure.Storage.Blob.SharedAccessBlobPermissions.Read,
       SharedAccessExpiryTime = DateTime.UtcNow.AddHours(1),
});

return myBlob.Uri.AbsoluteUri + sharedAccesSignature;

It tried many things at client side, resulting sometimes in 404, or 403 server error.
For exemple I tried this (result : 404) :

var blobClient = new CloudBlobClient(new Uri(blobWithSharedAccessSignature));
// blobWithSharedAccessSignature here is : https://azertyuiop.blob.core.windows.net/container1/Imports/2012-12-01_19-43-54.zip?sv=2012-02-12&se=2012-12-01T20%3A43%3A54Z&sr=b&sp=rw&sig=h0bTUk[...]3D
// calling blobWithSharedAccessSignature from a webBrowser works.
// result here is valid for containerName : container1
var container = blobClient.GetContainerReference(containerName);
ICloudBlob blobRef = container.GetBlobReferenceFromServer(blobWithSharedAccessSignature);   ==> error 404
using (var fileStream = File.OpenRead(fileFullPath))
{
    blobRef.UploadFromStream(fileStream);
}

I tried replacing

container.GetBlobReferenceFromServer(blobWithSharedAccessSignature);

by

container.GetBlockBlobReference(blobWithSharedAccessSignature);

I also tried replacing

blobClient = new CloudBlobClient(new Uri(blobWithSharedAccessSignature));

by

blobClient = new CloudBlobClient(new Uri(blobWithSharedAccessSignature), new StorageCredentials(blobWithSharedAccessSignature));

which results in a “403 – forbidden” error.

Can someone help me by giving a full sample in v2 ? Or tell me were’s my mistake ? Thanks !

UPDATE – solution here : (thanks to Sandrino Di Mattia)

// Assuming that blobWithSharedAccessSignature is : 
//  "https://azertyuiop.blob.core.windows.net/container1/Imports/2012-12-01_19-43-54.zip?sv=2012-02-12&se=2012-12-01T20%3A43%3A54Z&sr=b&sp=rw&sig=h0bTUkTR%2FdTF%2BVZgDUuBPHqG%2BiTtFeXK4kepBpDR2AU%3D"
Uri blobUriWithoutCredentials = new Uri(new Uri(blobWithSharedAccessSignature).GetLeftPart(UriPartial.Path));
// here blobUriWithoutCredentials is https://azertyuiop.blob.core.windows.net/container1/Imports/2012-12-01_19-43-54.zip
string credentials = blobWithSharedAccessSignature.Substring(blobWithSharedAccessSignature.IndexOf('?'));
// here credentials is "?sv=2012-02-12&se=2012-12-01T22%3A26%3A55Z&sr=b&sp=rw&sig=Lsk8kLyJ8TFoGNVLbFLftCIXUNlIIRPZalkhoPdUfh8%3D"
var blobClient = new CloudBlobClient(blobUriWithoutCredentials, new StorageCredentials(credentials));
ICloudBlob blobRef = blobClient.GetBlobReferenceFromServer(blobUriWithoutCredentials);
using (var fileStream = File.OpenRead(fileFullPath))
{
    blobRef.UploadFromStream(fileStream);
}

Answer 1

When initializing the CloudBlobClient you need to pass 2 parameters

• baseUri: Blob url without SAS, http://test.blob.core.windows.net/temp/Imports/2012-12-01_20-56-52.zip
• credentials: This should be your SAS without the url, ?sv=2012-02-12&se=2012-12-01T21%3A57%3A56Z&sr=b&sp=rw&sig=5JboXXM1Yeo%2BuI6mb18VbURluo%3D

Working sample:

var blobClient = new CloudBlobClient(new Uri(blob.Uri.AbsoluteUri), new StorageCredentials(sharedAccesSignature));
using (var fileStream = File.OpenRead(fileFullPath))
{

    blobClient.GetBlobReferenceFromServer(new Uri(blob.Uri.AbsoluteUri))
                .UploadFromStream(fileStream);
}

Extra tip: You don’t need to get a reference to the container. You can immediately access the blob by calling GetBlobReferenceFromServer on the CloudBlobClient.