GetCustomerPurchaseIdAsync returns empty string

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Summary

The GetCustomerPurchaseIdAsync method returns an empty string when using the Windows.Services.Store namespace, and a 401 Unauthorized exception when using CurrentApp.GetCustomerPurchaseIdAsync through the Windows.ApplicationModel.Store namespace. This issue occurred after a period of successful functionality without any code changes.

Root Cause

The root cause of this issue is likely due to:

  • Invalid or expired access token: The access token used in the serviceTicket parameter may be invalid or expired, causing the 401 Unauthorized exception.
  • Incorrect audience or scope: The audience or scope used to acquire the access token may not match the requirements of the GetCustomerPurchaseIdAsync method.
  • Changes in Azure AD or Microsoft Store configuration: Changes in the Azure AD or Microsoft Store configuration, such as updates to the app registration or secret, may have caused the issue.

Why This Happens in Real Systems

This issue can occur in real systems due to:

  • Token expiration: Access tokens have a limited lifetime and may expire, causing the 401 Unauthorized exception.
  • Configuration changes: Changes in the Azure AD or Microsoft Store configuration can cause issues with the access token or scope.
  • Network or server issues: Network or server issues can cause problems with the access token acquisition or validation process.

Real-World Impact

The real-world impact of this issue includes:

  • Failed subscription management: The inability to retrieve the customer purchase ID can prevent successful subscription management, leading to issues with customer entitlements and revenue tracking.
  • Poor user experience: The 401 Unauthorized exception or empty string return value can cause errors and frustration for users, leading to a poor overall experience.
  • Revenue loss: Failed subscription management can result in revenue loss due to untracked or unfulfilled customer subscriptions.

Example or Code

var app = ConfidentialClientApplicationBuilder
    .CreateWithApplicationOptions(new ConfidentialClientApplicationOptions()
    {
        AzureCloudInstance = AzureCloudInstance.AzurePublic,
        TenantId = _options.TenantId,
        ClientId = _options.ClientId,
        ClientSecret = _options.ClientSecret,
    })
    .Build();

var scopes = new[] { "https://onestore.microsoft.com/b2b/keys/create/purchase/.default" };
var authResult = await _app.AcquireTokenForClient(scopes).ExecuteAsync(ct);
var token = authResult.AccessToken;

How Senior Engineers Fix It

Senior engineers can fix this issue by:

  • Verifying the access token: Checking the access token for validity and expiration.
  • Checking the audience and scope: Ensuring the audience and scope used to acquire the access token match the requirements of the GetCustomerPurchaseIdAsync method.
  • Updating the Azure AD or Microsoft Store configuration: Updating the app registration, secret, or other configuration settings as needed.
  • Implementing token renewal: Implementing a token renewal process to handle expired access tokens.

Why Juniors Miss It

Junior engineers may miss this issue due to:

  • Lack of understanding of Azure AD and Microsoft Store configuration: Limited knowledge of the Azure AD and Microsoft Store configuration requirements.
  • Insufficient testing: Inadequate testing of the access token acquisition and validation process.
  • Failure to handle token expiration: Not implementing a token renewal process to handle expired access tokens.
  • Inadequate error handling: Not properly handling errors and exceptions, such as the 401 Unauthorized exception.