CODEWITHSUNDEEP
azure
Reft
Reft

Reputation: 2433

Azure Shared Access Signatures (SAS)

I started using SAS today for the first time and I was intrigued by it but.. Would i really need it in my current project?

On my azure website, I want users to be able to upload and download blobs. Every user has their own account.

This is a simple upload function:

//Upload blob
            CloudBlobContainer container = CloudStorageServices.GetCloudBlobsContainer();
            CloudBlockBlob blockBlob = container.GetBlockBlobReference(file.FileName + guid);
            blockBlob.UploadFromStream(file.InputStream);

            //Get uri from blob
            var blobUrl = blockBlob.Uri;

            //Upload table
            CloudTable table2 = CloudStorageServices.GetCloudUploadsTable();
            UploadEntity uploadtable = new UploadEntity(imagename, entity.RowKey + guid, blobUrl.ToString(), User.Identity.Name, file.FileName + guid);
            TableOperation insertOperation = TableOperation.InsertOrReplace(uploadtable);
            table2.Execute(insertOperation);

I dont really see the point in using SAS here, but i have feeling im totally wrong.. Why should I use it?

When user has uploaded a blob, the belonging blobs(uploaded by that user) will be listed and the user will ONLY be able to select and download their own items, Javascript download.

Same here.. Why would i need SAS?

Thanks!!

Upvotes: 0

Views: 151

Answers (1)

Shaun Xu
Shaun Xu

Reputation: 4656

If you have a website or web service in front of your blobs then you don't need to use SAS since you can control the user permission by yourself. I used SAS in most cases that I cannot control the user permission.

For example, then we need to display images directly from the blob URL, I need to prevent them from being loaded and displayed by other websites. So I will generate SAS for the images needs to be displayed on that page and change the page html content to the SAS URL with few seconds. So if other wanted to read images by these SAS URLs they will be expired.

Another example might be upload. Different from your scenario if you need someone to upload directly to blob then you might need SAS since you should not give them your storage security keys.

Hope this helps a bit.

Upvotes: 3

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