Using REST api with HttpWebRequest to an Azure Blob store

Hi All,

I've been pulling my hair out over this for a few days now and I feel I'm close.

I am trying to interact with an Azure Blob storage using the REST api via HttpWebRequest in Unity3D. My hope is that this will be bare bones enough to re-use on basically any platform but I'm stuck at getting it to work on my Win8.1 machine just in the free Unity3D editor.

I had initially been getting issue trying to authenticate with the server but I think I've managed to resolve the authentication header using sharekeylite but now I'm getting a Tlsexception.

When I run the code at the bottom I currently get the following error on line 54:

Code (csharp):

1. (HttpWebResponse)request.GetResponse()

I looked this up and it seemed to be related to my azure storage missing a crossdomain.xml so I created one with utf-8 formatting and put it in a storage container called "$root" on my blob server with the following content (for testing - although I'm not sure what I should have in there for production?):

Code (csharp):

1.     <?xml version="1.0" ?>
2.     <cross-domain-policy>
3.     <allow-access-from domain="*" />
4.     </cross-domain-policy>

This is the complete code I'm testing with at the moment (security details altered):

Code (csharp):

1. using UnityEngine;
2. using System.Security.Cryptography;
3. using System.Xml.Linq;
4. using System.Globalization;
5. using System.Collections;
6. using System.Text;
7. using System.Net;
8. using System.IO;
9. using System;
10.  
11. public class DatabaseClient : MonoBehaviour {
12.  
13.     string accessKey = "myAccessKeyFromAzureStorageManageAccessKey==";
14.     string accountName = "accountName";
15.     string container = "test"; //Storage container created on azure portal called "test"
16.  
17.     // Use this for initialization
18.     void Start () {
19.         GetBlob_Test();
20.     }
21.    
22.     // Update is called once per frame
23.     void Update () {
24.    
25.     }
26.  
27.     // GetBlob_Test
28.     void GetBlob_Test()
29.     {
30.         Debug.Log ("Attempting to GET from server");
31.         DateTime dt = DateTime.UtcNow;
32.  
33.         string stringToSign = String.Format("GET\n"
34.                                             + "\n" // content md5
35.                                             + "\n" // content type
36.                                             + "x-ms-date:" + dt.ToString("R") + "\nx-ms-version:2012-02-12\n" // headers
37.                                             + "/{0}/{1}\ncomp:list\nrestype:container", accountName, container);
38.  
39.         string authorizationKey = SignThis(stringToSign, accessKey, accountName);
40.         string method = "GET";
41.         string urlPath = string.Format("https://{0}.blob.core.windows.net/{1}?restype=container&comp=list", accountName, container);
42.         Uri uriTest = new Uri(urlPath);
43.  
44.         HttpWebRequest request = (HttpWebRequest)WebRequest.Create (uriTest);
45.         request.Method = method;
46.         request.Headers.Add("x-ms-date", dt.ToString("R"));
47.         request.Headers.Add("x-ms-version", "2012-02-12");
48.         request.Headers.Add("Authorization", authorizationKey);
49.  
50.         Debug.Log ("Authorization: " + authorizationKey);
51.  
52.         using (HttpWebResponse response = (HttpWebResponse)request.GetResponse())
53.         {
54.             Debug.Log("Response = " + response);
55.         }
56.     }
57.  
58.     private static String SignThis(String StringToSign, string Key, string Account)
59.     {
60.         String signature = string.Empty;
61.         byte[] unicodeKey = Convert.FromBase64String(Key);
62.         using (HMACSHA256 hmacSha256 = new HMACSHA256(unicodeKey))
63.         {
64.             Byte[] dataToHmac = System.Text.Encoding.UTF8.GetBytes(StringToSign);
65.             signature = Convert.ToBase64String(hmacSha256.ComputeHash(dataToHmac));
66.         }
67.        
68.         String authorizationHeader = String.Format(
69.             CultureInfo.InvariantCulture,
70.             "{0} {1}:{2}",
71.             "SharedKeyLite",
72.             Account,
73.             signature);
74.        
75.         return authorizationHeader;
76.     }
77. }

Any help would be much appreciated.

Thanks,
Hobsie

 

Turns out that the web address was slightly wrong (https instead of http).

That brings me back to the server returning error: 403

Edit:

This issue was eventually resolved. Turns out it was simply a malformed verification header.

I ended up using Fiddler to intercept the calls made by Unity to the server and looked at the error message which showed what it was expecting the verification header to be created as versus what it was actually given.

 

I am wondering what was wrong with the header? I am trying to do this also and cant figure it out

 

I am also interested... I am getting the same error. Impossible to figure out why.
The same codes runs fine out of Unity from Visual Studio. I suppose it is something related to Mono ?
Any help is welcomed...

 

(would be interested to know @mhobbs_GTDC 's solution also)

EDIT: Our savior, my hero @andgelsin has a solution. Just tested and all working: Thread link.

 

Thanks @kor for the edit and the solution link

 

I've shared an Azure Blob Storage Unity project that may be helpful to you -
https://github.com/Unity3dAzure/StorageServicesDemo
https://github.com/Unity3dAzure/StorageServices

- It supports Windows Store Apps also

 

I just tried and after 2 hours Im pretty sure its no longer supported anymore..