Always Encrypted with Intel SGX enclaves in Azure SQL Database - Demos

The demos in this folder showcase Always Encrypted with secure enclaves in Azure SQL Database. The demos use the Contoso HR web application.

Contents

About this sample
Before you begin
Setup
Demo 1 - a tour of the demo environment
Demo 2 - a short demo of key benefits of secure enclaves
Demo 3 - a longer demo showcasing in-place encryption and rich queries
Cleanup

About this sample

• Applies to: Azure SQL Database
• Key features: Always Encrypted with secure enclaves
• Workload: Human resources (HR) application
• Programming Language: C#, Transact-SQL
• Authors: Jakub Szymaszek, Pieter Vanhove
• Update history:

Before you begin

Before you begin, you need an Azure subscription. If you don't already have an Azure subscription, you can get one for free here.

You also need to make sure the following software is installed on your machine:

1. PowerShell modules:

   1. Az version 9.3 or later. For details on how to install the Az PowerShell module, see Install the Azure Az PowerShell module. To determine the version of the Az module installed on your machine, run the following command from a PowerShell session.

   Get-InstalledModule -Name Az

   2. SqlServer version 22.0.49-preview or later. For details on how to install the SqlServer PowerShell module, see Installing or updating the SqlServer module. To determine the version the SqlServer module installed on your machine, run the following command from a PowerShell session.

   Get-InstalledModule -Name SqlServer

2. Bicep version 0.13.1 or later. You need to install Bicep and ensure it can be invoked from PowerShell. The recommended way to achieve that is to install Bicep manually with PowerShell.

3. SQL Server Management Studio - version 19 or later is recommended.

Setup

By following the below setup steps, you will create a new resource group and deploy the following resources to your Azure subscription:

• A logical database server.
• The ContosoHR database using the DC-series hardware generation, which is required for Always Encrypted with secure enclaves.
• A key vault in Azure Key Vault and a key to be used as a column master key for Always Encrypted.
• The Contoso HR web application in Azure Web Apps.
• An attestation provider in Microsoft Azure Attestation. Your web app will use the attestation provider to attest the enclave in the database.

Setup steps:

1. Clone/download and unpack the repository.

2. Open a PowerShell session.

3. In the PowerShell session, change the directory to the setup folder within this demo's directory. For example, if you've unpacked the downloaded repository on a Windows machine in C:\, issue the following command:

   cd "C:\sql-server-samples\samples\features\security\always-encrypted-with-secure-enclaves\azure-sql-database\setup"

4. Run the setup.ps1 PowerShell script.

5. When prompted, enter the following information:

   1. Your Azure subscription id. To determine your subscription id, see Find your Azure subscription.
   2. The project name. The resource group containing all your demo resources will have that name. The project name will also be used as a prefix for the names of all demo resources. Please use only lowercase letters and numbers for the project name and make sure it is unique.
   3. The location - it must be one of the Azure regions supporting the DC-series hardware generation, which are listed here.
   4. The username and the password of the Azure SQL database server administrator. The setup script will create the server with these admin credentials and it will later use them to connect to the server using SQL authentication for some of the setup steps.

6. When prompted, sign in to Azure. Once you sign in, the script will deploy the demo environment using the provided Bicep template, which may take a few minutes. After the deployment completes, the script performs post-deployment setup steps to configure the database and the attestation policy for Always Encrypted with secure enclaves.

7. When prompted, sign in to Azure again, to enable the SqlServer PowerShell module to connect to the database.

8. Finally, the script outputs the important information about your demo environment.

   • Database server name (<project name>server.database.windows.net)
   • Database name (ContosoHR)
   • Attestation URL (https://<project name>attest.<region moniker>.attest.azure.net)
   • Application URL (https://<project name>app.azurewebsites.net/)

   Please copy and save the above information. You will need it for the demo steps.

Demo 1

In this demo, you will take a tour of the demo environment, in which Always Encrypted with secure enclaves is already set up and sensitive data columns in the database are already encrypted.

Prepare for the demo

Perform the below steps before each demo presentation.

1. Close all running instances of SQL Server Management Studio (SSMS).

2. Prepare a new instance of SSMS.

   1. Start SSMS.

   2. In the Connect to Server dialog:

      1. In the main page of the dialog, enter your database server name. Set Authentication to Azure Active Directory – Universal with MFA. In the User Name field, enter your Azure AD username. You should enter the same username, you used to sign in to Azure, when you set up your demo environment.

      

      1. Click Connect.
      2. When prompted, sign in to Azure.

3. Prepare your web browser.

   1. Open a new tab in the browser and point it to Azure Portal: https://portal.azure.com.
   2. Sign in to Azure if prompted.
   3. In the Search box in the Azure Portal, enter the name of your demo resource group and click Enter. In the search results, click on your resource group. You should see the content of your resource group, which should look like this:

   

Demos steps

1. Review the content of your demo resource group. It should contain the following resources:

   • <project name>app- an app service hosting the Contoso HR web application.
   • <project name>attest- an attestation provider in Microsoft Azure Attestation for attesting the secure enclave for the ContosoHR database.
   • <project name>identity - a user-assigned managed identity that was used to deploy the web application.
   • <project name>plan - an app service plan for the web application.
   • <project name>server- a logical server in Azure SQL Database.
   • <project name>vault - a key vault in Azure Key Vault, containing the column master key for Always Encrypted.
   • ContosoHR - a database.

2. Right-click on the ContosoHR database in the resource group and open its Overview blade in the new tab. Click on Compute + storage under Settings. Click Change configuration. Note that the database is already configured to use the DC-series hardware configuration that supports confidential computing using secure enclaves. Setting the DC-series hardware configuration for a database is required to use Always Encrypted with secure enclaves in the database. For more information, see Enable Intel SGX for your Azure SQL Database. In the left ribbon, click on Data Encryption and click in the blade on Always Encrypted. Confirm that the Secure Enclave is enabled and that the enclave type is Intel Software Guard Extension (Intel SGX)

   

3. Close the browser tab for the database. Right-click on the attestation provider in your resource group and open its Overview blade in a new tab. Click on Policy under Settings. Select SGX-IntelSDK for Attestation Type. This will display the attestation policy configured for Intel Software Guard eXtensions (Intel SGX) enclaves. The policy allows a client driver within an application to verify the secure enclave in Azure SQL Database is a genuine Intel SGX enclave and it runs the genuine SQL library that implements Transact-SQL predicates and cryptographic operations of Always Encrypted. For more information, see Configure Azure Attestation for your Azure SQL logical server.

   

4. Close the browser tab for the attestation provider. Right-click on the app service for the Contoso HR web application in your resource group and open its Overview blade in a new tab. Click on Configuration under Settings. In the Connection strings section, click Advanced edit. This will display the database connection string configured for the web application. There are three important things to call out in the database connection string:

   • Column Encryption Setting = Enabled turns the Always Encrypted on in the client driver, allowing it to transparently encrypt query parameters and decrypt query results.
   • Attestation Protocol = AAS specifies Microsoft Azure Attestation is used for attesting the secure enclave for the ContosoHR database.
   • Enclave Attestation Url is an attest URI of the attestation provider.

   

5. Close the browser tab for the app service. Right-click on the key vault in your resource group and open its Overview blade in a new tab.

   1. Click on Keys under Settings. You should see the entry for the key, named CMK - this is your column master key for Always Encrypted.

      

   2. Click on Access Policies under Settings. You should see two access policy entries: one for your identity and one for the web app's identity. These policies grant you permissions necessary to perform key management operations and they grant the web app permissions required to decrypt column encryption keys, protecting the data.

6. Switch to SSMS.

   1. In Object Explorer, navigate to the ContosoHR database. Then go to Security > Always Encrypted Keys.

   2. Open the Column Master Keys and Column Encryption Keys folders. You should see the metadata object, named CMK1, for the column master key and the metadata object, named CEK1, for the column encryption key.

   3. Right click on CMK1 and select Properties. Note that the metadata object references the key in the key vault. Also note Enclave Computations is set to Allowed, which permits the column encryption key, this columns master key protects, to be used in enclave computations.

      

Key Takeaways

Always Encrypted with Intel SGX enclaves requires specific hardware that is exposed in Azure SQL Database as the DC-series hardware configuration. Microsoft Azure Attestation is a Platform-as-a-Service solution for attestation enclaves in Azure. Enclaves are attested against a policy, you define and control.

Demo 2

This short demo highlights the main benefits of Always Encrypted with secure enclaves. The starting point for the demo is the ContosoHR database with the SSN and Salary columns already encrypted.

Prepare for the demo

Perform the below steps before you show the demo.

1. Close all running instances of SQL Server Management Studio (SSMS).
2. Prepare a new instance of SSMS.

   1. Start SSMS.

   2. In the Connect to Server dialog:

      1. In the main page of the dialog, enter your database server name. Set Authentication to Azure Active Directory – Universal with MFA. In the User Name field, enter your Azure AD username. You should enter the same username, you used to sign in to Azure, when you set up your demo environment.

         

      2. Click the Options >> button, select the Connection Properties tab and enter the database name (ContosoHR).

         

      3. Select the Always Encrypted tab. Make sure the Enable Always Encrypted checkbox is not selected.

         

      4. Click Connect.

      5. When prompted, sign in to Azure.

   3. Configure query windows.

      1. In Object Explorer, find and select the ContosoHR database.

      

      1. With the ContosoHR database selected, click Ctrl + O. In the Open File dialog, navigate to the tsql-scripts folder and select ListAllEmployees.sql. Do not execute the query yet.
      2. With the ContosoHR database selected, click Ctrl + O. In the Open File dialog, navigate to the tsql-scripts folder and select QueryEvents.sql. Do not execute the query yet.
3. Prepare your web browser.

   1. Open your browser.

   2. Point the browser to the demo application URL.

      

Demos steps

1. Show the Contoso HR web app in the the browser. This application displays employee records and it allows you to filter and sort employees by salary or by a portion of the social security number (SSN). Move the salary slider and enter a couple of digits in the search box to filter by salary and SSN. Click on the Ssn or Salary column header to filter by salary or SSN.

   

2. Switch to SSMS, select the ListAllEmployees.sql tab and click F5 to execute the query, which shows the content of the Employees table, the web application uses as a data store. Although you are a DBA of the database, you cannot see the plaintext data in the SSN and Salary columns, as those two columns are protected with Always Encrypted.

   

3. Select the QueryXevents.sql tab and click F5 to execute the query. This query retrieves extended events from the Demo extended event session, configured in the ContosoHR database. Each extended event captures a query the web application has sent to the database.

   

4. Click on the link in the second column of the first row of the result set to see the extended event with the latest query from the application. This will open the extended event in the new tab.

   1. Review the query statement. Note that the query contains the WHERE clause with rich computations on encrypted columns: pattern matching using the LIKE predicate on the SSN column and the range comparison on the Salary column. The query also sorts records (the ORDER BY clause) by SSN or Salary. Pro Tip: to make it easier to view the query statement, you can put line brakes in it.

      

   2. Locate the value of query parameters: @SSNSearchPattern, @MinSalary, @MaxSalary. Note that the values of the parameters are encrypted – the client driver inside the web app transparently encrypts parameters corresponding to encrypted columns, before sending the query to the database. Not only does not the DBA have access to sensitive data in the database, but the DBA cannot see the plaintext values of query parameters used to process that data either.

Key Takeaways

Always Encrypted with secure enclaves allows applications to perform rich queries on sensitive data without revealing the data to potentially malicious insiders, including DBAs in your organization.

Demo 3

The starting point for this demo is the database with no columns encrypted - the data is initially not protected. The demo shows how to reach the following two objectives:

1. Protect sensitive data in the database by encrypting it in-place.
2. Ensure the Contoso HR web application can continue run rich queries on database columns after encrypting the columns.

During the demo, you will use two instances of SQL Server Management Studio (SSMS):

• DBA's instance - when using it, you will assume the role of a DBA.
• Security Adminsitrator's instance - when using it, you will assume the role of a Security Administrator, who configures Always Encrypted in the database.

Prepare for the demo

Perform the below steps before you show the demo.

1. Close all running SSMS instances.
2. Prepare DBA's instance of SSMS.
   1. Start SSMS.
   2. In the Connect to Server dialog:

      1. In the main page of the dialog, enter your database server name. Set Authentication to Azure Active Directory – Universal with MFA. In the User Name field, enter your Azure AD username. You should enter the same username, you've used to sign in to Azure, when you set up your demo environment.

         

      2. Click the Options >> button, select the Connection Properties tab and enter the database name (ContosoHR).

         

      3. Select the Always Encrypted tab. Make sure the Enable Always Encrypted checkbox is not selected.

         

      4. Click Connect.

      5. When prompted, sign in to Azure.

   3. Configure query windows.

      1. In Object Explorer, find and select the ContosoHR database.

         

      2. With the ContosoHR database selected, click Ctrl + O. In the Open File dialog, navigate to the tsql-scripts folder and select ListAllEmployees.sql. Do not execute the query yet.

      3. With the ContosoHR database selected, click Ctrl + O. In the Open File dialog, navigate to the tsql-scripts folder and select QueryEvents.sql. Do not execute the query yet.

3. Prepare Security Administrator's instance of SSMS.
   1. Start SSMS.
   2. In the Connect to Server dialog:

      1. In the main page of the dialog, enter your database server name. Set Authentication to Azure Active Directory – Universal with MFA. In the User Name field, enter your Azure AD username. You should enter the same username, you've used to sign in to Azure, when you set up your demo environment.

         

      2. Click the Options >> button, select the Connection Properties tab and enter the database name (ContosoHR).

         

      3. Select the Always Encrypted tab. Make sure the Enable Always Encrypted and the Enable secure enclaves checkbox are selected. Set the Enclave attestation Protocol to Microsoft Azure Attestation and enter your attestation URL.

         

      4. Click Connect.

      5. When prompted, sign in to Azure.

   3. Configure query windows.

      1. In Object Explorer, find and select the ContosoHR database.

         

      2. With the ContosoHR database selected, click Ctrl + O. In the Open File dialog, navigate to the tsql-scripts folder and select DecryptColumns.sql. Click F5 to execute the query, which will decrypt the SSN and Salary columns in the database.

      3. With the ContosoHR database selected, click Ctrl + O. In the Open File dialog, navigate to the tsql-scripts folder and select EncryptColumns.sql. Do not execute the query yet.

4. Prepare your web browser.

   1. Open your browser.

   2. Point the browser to the demo application URL.

      

Demos steps

1. Show the Contoso HR web app in the the browser. This application displays employee records and allows you to filter employees by salary or by a portion of the social security number (SSN). Move the salary slider and enter a couple of digits in the search box to filter by salary and SSN.

   

2. Switch to DBA's instance of SSMS, select the ListAllEmployees.sql tab and click F5 to execute the query, which shows the content of the Employees table, the web application uses as a data store. As a DBA, you can view all sensitive information about employees, including the data stored in the SSN and Salary columns. A malicious DBA could easily exfiltrate the data by running a simple query like this one.

   

3. Select the QueryXevents.sql tab and click F5 to execute the query. This query retrieves extended events from the Demo extended event session, configured in the ContosoHR database. Each extended event captures a query the web application has sent to the database.

   

4. Click on the link in the second column of the first row of the result set to see the extended event with the latest query from the application. This will open the extended event in the new tab.

   1. Review the query statement. Note that the query contains the WHERE clause with rich computations on encrypted columns: pattern matching using the LIKE predicate on the SSN column and the range comparison on the Salary column. The query also sorts records (the ORDER BY clause) by SSN or Salary. Pro Tip: to make it easier to view the query statement, you can put line brakes in it.

      

   2. Locate the value of query parameters: @SSNSearchPattern, @MinSalary, @MaxSalary. Note that the values of the parameters are in plaintext, as the columns, the parameters correspond to, are not encrypted.

5. Switch to Security Administrator's instance of SSMS, select the EncryptColumns.sql tab and click F5 to execute the query, encrypts the data in the SSN and Salary columns in place, using the secure enclave.

6. Switch back to DBA's instance of SSMS, select the ListAllEmployees.sql tab and click F5 to execute the query again. Now the query should show the encrypted data in the SSN and Salary columns. As both columns are encrypted, the DBA cannot see the data in plaintext.

   

7. In the web browser, move the slider to reset the filter for salary and then re-enter a few digits of an SSN. Confirm the application still can filter employee records by salary and SSN.

8. Switch to DBA's instance of SSMS, select the QueryXevents.sql tab and click F5 to re-run the query.

9. Click on the link in the second column of the first row of the result set to see the extended event with the latest query from the application. This will open the extended event in the new tab.

   1. Review the query statement. Note that the query statement the query sends to the database has not changed - it still contains pattern matching using the LIKE predicate on the SSN column and the range comparison on the Salary column, as well as sorting (the ORDER BY clause) by SSN or Salary. Pro Tip: to make it easier to view the query statement, you can put line brakes in it.

      

   2. Locate the value of query parameters: @SSNSearchPattern, @MinSalary, @MaxSalary. Note that the values of the parameters are now encrypted – the client driver inside the web app transparently encrypts parameters corresponding to encrypted columns, before sending the query to the database. Not only does not the DBA have access to sensitive data in the database, but the DBA cannot see the plaintext values of query parameters used to process that data either.

Key Takeaways

Secure enclaves make it possible to encrypt sensitive data columns in-place, eliminating a need to move the data outside of the database for cryptographic operations.

The unique benefit of Always Encrypted with secure enclaves is that it allows you to protect your sensitive data from high-privilege users, including DBAs in your organization, and, after you encrypt your data to protect it, your applications can continue running rich queries on encrypted columns.

Cleanup

To permanently remove all demo resources:

1. Run the cleanup.ps1 PowerShell script in the setup folder.
2. When prompted, enter your demo resource group name and your subscripton id, and sign in to Azure.
3. Confirm you want to delete resource group.
4. Confirm you want to permanently delete the key vault.