Securing Your SharePoint and Windows Azure Solutions : Create a Windows Forms Application to Display the Shared Access Permissions Signature

Open Microsoft Visual Studio 2010 and create a blank solution.

Right-click the solution and select Add | New Project.

Select Windows Forms Application, provide a name for the application (such as BLOBUriGenerator), and click OK.

Right-click the project and select Add References. Add Microsoft.WindowsAzure.StorageClient.dll (from C:\Program Files\Windows Azure SDK\v1.3\bin).

Click View | Toolbox, drag two buttons onto the Windows Forms designer surface, and then drag a textbox control onto the designer surface. Your Windows Forms UI should look similar to the graphic shown here. Name the buttons btnGetData and btnExit. Name the textbox control txtbxURI.

Right-click the Form1.cs in the Solution Explorer and select View Code.

In the code-behind, amend the code by using the bolded code shown here:

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using Microsoft.WindowsAzure.StorageClient;
using Microsoft.WindowsAzure;

namespace BLOBUrlGenerator
{
    public partial class Form1 : Form
    {

        CloudBlobContainer azureBlobContainer = null;
        CloudStorageAccount azureStorageAcct = null;
        CloudBlobClient azureBlobClient = null;
        BlobContainerPermissions azureBlobPermissions = null;
        CloudBlob azureBlob = null;
        string submissionDateTime = "";

        public Form1()
        {
            InitializeComponent();
            InitializeStorage();
        }

        private void InitializeStorage()
        {
            var accountInfo = "DefaultEndpointsProtocol=http;Accountname=fabrikaminc;
AccountKey=<your account key here>

            azureStorageAcct = CloudStorageAccount.Parse(accountInfo);

            azureBlobClient = azureStorageAcct.CreateCloudBlobClient();

            azureBlobContainer = azureBlobClient.GetContainerReference(
               "c10testcontainer");
            azureBlobContainer.CreateIfNotExist();
            azureBlob = azureBlobContainer.GetBlobReference("c10testblob");
            azureBlob.UploadText("Test Text");
        }

        private void btnGetURI_Click(object sender, EventArgs e)
        {
            SharedAccessPolicy tempAccess = new SharedAccessPolicy();
            tempAccess.SharedAccessStartTime = DateTime.Now;
            tempAccess.SharedAccessExpiryTime = DateTime.Now.AddHours(48);
            tempAccess.Permissions = SharedAccessPermissions.Read;

            BlobContainerPermissions tempPermissions = new BlobContainerPermissions();
            tempPermissions.SharedAccessPolicies.Clear();
            tempPermissions.SharedAccessPolicies.Add("John Doe", tempAccess);
            azureBlobContainer.SetPermissions(tempPermissions);

            string sharedAccessSig = azureBlobContainer.
               GetSharedAccessSignature(tempAccess);
            string sharedAccessURI = azureBlobContainer.Uri.AbsoluteUri +
               sharedAccessSig;

            txtbxURI.Text = sharedAccessURI;
        }

        private void btnExit_Click(object sender, EventArgs e)
        {
            Application.Exit();
        }
    }
}

The preceding code uses the Microsoft.WindowsAzure.StorageClient library to programmatically interact with a Windows Azure BLOB storage account. You’ll note that there are several class-level declarations in the snippet, which represent the different storage objects that you need when interacting with Windows Azure BLOB storage. Then, as was discussed earlier in this section, you use the SharedAccessPolicy class to create a temporary shared access permissions signature, which can be used to download data and information from the BLOB. The shared access permissions URI that is created (sharedAccessURI) is then displayed in the textbox property.

After you finish adding the code, press F5 to debug the application. You should see something similar to the following—which exposes the shared access permissions signature in the form of a URI.