What is the proper way to authorize blob upload operation in Windows Azure Storage Client?

Question

I need to create a library that will allow me to upload blob data to certain Azure account. The following parameters will be provided dynamically, by external webservice:

x-ms-date, x-ms-version, Content-MD5, x-ms-blob-type, Content-Type, Authorization

According to examples here:

https://azure.microsoft.com/en-us/documentation/articles/storage-dotnet-shared-access-signature-part-1/

I should be able to upload the blob data by only URL and SasToken with something like:

Uri blobUri = new Uri("http://127.0.0.1:10000/devstoreaccount1/sascontainer/myblob.txt");

// Create credentials with the SAS token. The SAS token was created in previous example.
StorageCredentials credentials = new StorageCredentials(sasToken);

// Create a new blob.
CloudBlockBlob blob = new CloudBlockBlob(blobUri, credentials);

// Upload the blob.
// If the blob does not yet exist, it will be created.
// If the blob does exist, its existing content will be overwritten.
using (var fileStream = System.IO.File.OpenRead(@"c:\Temp\myblob.txt"))
{
    blob.UploadFromStream(fileStream);
}

However, the above assume that sasToken looks similar to this:

?sv=2015-07-08&sr=c&si=mypolicy&sig=FQctgR3waFrWpblkNJf6HYXAVa0%2BkxFUbP8Fr2op%2F%2FI%3D

While my serwice will only be provided with this:

{
    "Key": "Authorization",
    "Value": "SharedKey storageAccountName:Tz7EqAl6OszIxGjBUk2qcxs82Af4Xq9CxyFx6u34LEI="
}

I have found some examples here:

https://msdn.microsoft.com/en-us/library/azure/dd179451.aspx

On how to do this with REST API:

Request Syntax:
PUT https://myaccount.blob.core.windows.net/mycontainer/myblockblob HTTP/1.1

Request Headers:
x-ms-version: 2015-02-21
x-ms-date: <date>
Content-Type: text/plain; charset=UTF-8
x-ms-blob-content-disposition: attachment; filename="fname.ext"
x-ms-blob-type: BlockBlob
x-ms-meta-m1: v1
x-ms-meta-m2: v2
Authorization: SharedKey myaccount:YhuFJjN4fAR8/AmBrqBz7MG2uFinQ4rkh4dscbj598g=
Content-Length: 11

Request Body:
hello world

But since I'm new to Azure, I can't figure out how to do the above with storage client... Do I have to somehow manually "map" provided header parameters to query string parameters or is there a better/other way? Or perhaps this is not supported by Storage Client, and I should use REST approach?

EDIT1:

To be clear: I - more or less - know, how to upload the blob with sas token, as long as it has this form:

https://myaccount.blob.core.windows.net/mycontainer/myblockblob??sv=2015-07-08&sr=c&si=mypolicy&sig=FQctgR3waFrWpblkNJf6HYXAVa0%2BkxFUbP8Fr2op%2F%2FI%3D

Problem is - this token will NOT be provided - instead, the website we are trying to integrate with, will publish a webservice, and this webservice (which we have no control over) will provide the following five parameters (example data below):

{
  "Key": "x-ms-date",
  "Value": "Mon, 13 Jun 2016 10:22:05 GMT"
},
{
  "Key": "x-ms-version",
  "Value": "2015-04-05"
},
{
  "Key": "Content-MD5",
  "Value": "dnF5x6K/8ZZRzpfSlMMM+w=="
},
{
  "Key": "x-ms-blob-type",
  "Value": "BlockBlob"
},
{
  "Key": "Content-Type",
  "Value": "application/octet-stream"
},
{
  "Key": "Authorization",
  "Value": "SharedKey taxdocumentstorage09tst:sImBLJPWACNPzi94eJEDRU4Bt5hz9sPURjwy46KixmM="
}

Gaurav Mantri Gaurav Mantri · Accepted Answer · 2016-06-13T15:20:29

But since I'm new to Azure, I can't figure out how to do the above with storage client... Do I have to somehow manually "map" provided header parameters to query string parameters or is there a better/other way? Or perhaps this is not supported by Storage Client, and I should use REST approach?

You can't use Storage Client library as it computes some of these parameters and then invokes the REST API. What you would need to do is consume the REST API directly. Since you're getting all the values you need, you simply need to use HttpWebRequest/WebClient to make the REST API call, include necessary headers , send the request and process the response accordingly.

Important

Please ask the web service to include request URL as well in the parameters they send as it is used to calculate authorization header.

What is the proper way to authorize blob upload operation in Windows Azure Storage Client?

2 Answers