How can I secure simple HTML files using Azure AD? - azure

Question

I have a legacy static website that is just plain HTML and simple JavaScript for UI effects. There is no server side code, api, config files or anything in this website - just raw HTML files, CSS, pictures, etc.
The website will not be hosted in Azure. It will be on a local IIS server. If I pull the web site into Visual Studio, the "Configure Azure AD Authentication" wizard shows:
An incompatible authentication configuration was found in this project
().
How can I secure simple HTML files using Azure AD?

Answer 1

The Visual Studio "Configure Azure AD Authentication" wizard is intended for ASP.Net Web Apps and Web APIs.
In your case, what you are building is considered a "Single Page Application" or SPA. Even though you might have multiple pages, this term also applies to client side only web apps with no backend code.
For this, you should follow the Azure AD Javascript Single Page Application sample.
The gist of it is that you should us ADAL.js like shown in this sample's app.js, along the lines of:
// Configure ADAL
window.config = {
instance: 'https://login.microsoftonline.com/',
tenant: '[Enter your tenant here, e.g. contoso.onmicrosoft.com]',
clientId: '[Enter your client_id here, e.g. g075edef-0efa-453b-997b-de1337c29185]',
postLogoutRedirectUri: window.location.origin,
cacheLocation: 'localStorage', // enable this for IE, as sessionStorage does not work for localhost.
};
var authContext = new AuthenticationContext(config);
// Check For & Handle Redirect From AAD After Login
var isCallback = authContext.isCallback(window.location.hash);
authContext.handleWindowCallback();
$errorMessage.html(authContext.getLoginError());
if (isCallback && !authContext.getLoginError()) {
window.location = authContext._getItem(authContext.CONSTANTS.STORAGE.LOGIN_REQUEST);
}
// Check Login Status, Update UI
var user = authContext.getCachedUser();
if (user) {
//Do UI for authenticated user
} else {
//Show UI for unauthenticated user
}
// Register NavBar Click Handlers
$signOutButton.click(function () {
authContext.logOut();
});
$signInButton.click(function () {
authContext.login();
});
Note: There's also a Angular SPA sample.

Answer 2

The solution posted by Saca pointed me in the right direction, but adding the JS to every page was not a valid solution for me. There were thousands of HTML files, lots with no common JS file I could tack that ADAL code into. I would have had to find a way to insert that JS on all those pages.
My first solution was simply creating a normal .NET MVC app with the proper auth configured. Then I simply loaded this legacy content via an iFrame. This worked but was limiting for the users.
As Fei Xue mentioned in another comment, the next solution involved scrapping the iFrame but routing all requests for static files through a controller. Using this as a reference for understanding that: https://weblogs.asp.net/jongalloway/asp-net-mvc-routing-intercepting-file-requests-like-index-html-and-what-it-teaches-about-how-routing-works
The above solutions worked. However, eventually this app ended up as an Azure App Service and I simply turned on authentication at the app service level with just the pure html files.