Looking for a C# sample to upload/download file by given a Shared Access Signature (SAS) key

Question

Hi,

I found the link below link using C# to upload and download file. It is using a ConnectionString to establish the connection to Azure.
https://learn.microsoft.com/en-us/azure/storage/blobs/storage-quickstart-blobs-dotnet

I am looking for a sample to do the same by given an Azure Shared Access Signature (SAS). If anyone has a sample and would not mind sharing, I really appreciate it.

Thanks,
Brian.

Answer 1

Hello @Brian Ho ,
Here is the complete piece of C#.net code to download a blob from a container. I have successfully tested and able to download a blob using SAS Key.
Reference Code: https://gist.github.com/dazfuller/9b5ea145525879fb5114bd78b53e9ee5#file-azureblobdownload-cs

Please Note: If you get 403 Forbidden error, make sure to generate the SAS key with all the right permissions.

Fully tested code:

public static void DownloadFilesUsingSAS()

    {  

        const string accountName = "storageaccountname";  

        const string blobContainerName = "test";  

        const string downloadLocation = @"C:\data";  

        const string sasToken =                @"SASTOKEN";  

        // Create a credential object from the SAS token then use this and the account name to create a cloud storage connection  
        var accountSAS = new StorageCredentials(sasToken);  
        var storageAccount = new CloudStorageAccount(accountSAS, accountName, null, true);  

        // Get the Blob storage container  
        var blobClient = storageAccount.CreateCloudBlobClient();  
        var container = blobClient.GetContainerReference(blobContainerName);  

        // Fail if the container does not exist  
        if (!container.Exists())  
        {  
            Console.Error.WriteLine($"Can't find container '{blobContainerName}'");  
            return;  
        }  

        // Get the list of blobs in the container, just for demo purposes this is ordered by blob name and taking only  
        // the first 10 items  
        var blobs = container  
            .ListBlobs(blobListingDetails: BlobListingDetails.Metadata)  
            .OfType<CloudBlob>()  
            .OrderBy(blobItem => blobItem.Name)  
            .Take(10)  
            .ToList();  

        // Set the request options to ensure we're performing MD5 validation  
        var downloadOptions = new BlobRequestOptions  
        {  
            DisableContentMD5Validation = false,  
            UseTransactionalMD5 = true  
        };  

        // Download the files  
        // The parameters are named for reference only and can safely be removed  
        Task.WaitAll(  
            blobs.Select(  
                blobItem => blobItem.DownloadToFileAsync(  
                    path: Path.Combine(downloadLocation, blobItem.Name),  
                    mode: FileMode.Create,  
                    accessCondition: null,  
                    options: downloadOptions,  
                    operationContext: null)).ToArray());  
    }  

If the above answer helps out , kindly Upvote & Accept the answer.

Regards,
Shiva.

Answer 2

Hello @Brian Ho ,
Can you try installing Microsoft.WindowsAzure Nuget Packages using the solution explorer ?
Go to Solution Explorer -> Select References -> Right Click -> Manage Nuget Packages -> Search for WindowsAzure.Storage
In the search list, install the first one i.e. WindowsAzure.Storage.

Regards,
Shiva.