Fixes Logout error when using Easy Auth v2 (#1246)

#1234
AzureAD · Jun 7, 2021 · e435bbb · e435bbb
1 parent a4ef0d3
commit e435bbb
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Showing 3 changed files with 21 additions and 2 deletions.
diff --git a/src/Microsoft.Identity.Web/AppServicesAuth/AppServicesAuthenticationInformation.cs b/src/Microsoft.Identity.Web/AppServicesAuth/AppServicesAuthenticationInformation.cs
@@ -24,6 +24,7 @@ public static class AppServicesAuthenticationInformation
         internal const string AppServicesAuthIdentityProviderEnvironmentVariable = "WEBSITE_AUTH_DEFAULT_PROVIDER"; // AzureActiveDirectory
         internal const string AppServicesAuthAzureActiveDirectory = "AzureActiveDirectory";
         internal const string AppServicesAuthIdTokenHeader = "X-MS-TOKEN-AAD-ID-TOKEN";
+        internal const string AppServicesWebSiteAuthApiPrefix = "WEBSITE_AUTH_API_PREFIX";
         private const string AppServicesAuthIdpTokenHeader = "X-MS-CLIENT-PRINCIPAL-IDP";
 
         // Artificially added by Microsoft.Identity.Web to help debugging App Services. See the Debug controller of the test app
@@ -57,7 +58,22 @@ public static string? LogoutUrl
         {
             get
             {
-                return Environment.GetEnvironmentVariable(AppServicesAuthLogoutPathEnvironmentVariable);
+                // Try $AppServicesAuthLogoutPathEnvironmentVariable (AppServices auth v1.0)
+                string? logoutPath = Environment.GetEnvironmentVariable(AppServicesAuthLogoutPathEnvironmentVariable);
+                if (!string.IsNullOrEmpty(logoutPath))
+                {
+                    return logoutPath;
+                }
+
+                // Try the $(AppServicesWebSiteAuthApiPrefix)
+                string? webSite = Environment.GetEnvironmentVariable(AppServicesWebSiteAuthApiPrefix);
+                if (!string.IsNullOrEmpty(webSite))
+                {
+                    return $"{webSite}/logout";
+                }
+
+                // Fallback
+                return "/.auth/logout";
             }
         }
 

diff --git a/tests/Microsoft.Identity.Web.Test/WebAppExtensionsTests.cs b/tests/Microsoft.Identity.Web.Test/WebAppExtensionsTests.cs
@@ -71,6 +71,7 @@ private void ResetAppServiceEnv()
             Environment.SetEnvironmentVariable(AppServicesAuthenticationInformation.AppServicesAuthClientIdEnvironmentVariable, string.Empty);
             Environment.SetEnvironmentVariable(AppServicesAuthenticationInformation.AppServicesAuthClientSecretEnvironmentVariable, string.Empty);
             Environment.SetEnvironmentVariable(AppServicesAuthenticationInformation.AppServicesAuthLogoutPathEnvironmentVariable, string.Empty);
+            Environment.SetEnvironmentVariable(AppServicesAuthenticationInformation.AppServicesWebSiteAuthApiPrefix, string.Empty);
             Environment.SetEnvironmentVariable(AppServicesAuthenticationInformation.AppServicesAuthIdentityProviderEnvironmentVariable, string.Empty);
         }
 

diff --git a/tests/WebAppCallsMicrosoftGraph/Pages/Debugging.cshtml b/tests/WebAppCallsMicrosoftGraph/Pages/Debugging.cshtml
@@ -3,7 +3,9 @@
 @{
     string[] importantEnvironmentVariables = new string[] {
     "WEBSITE_AUTH_ENABLED", "WEBSITE_AUTH_OPENID_ISSUER", "WEBSITE_AUTH_CLIENT_ID",
-    "WEBSITE_AUTH_CLIENT_SECRET", "WEBSITE_AUTH_LOGOUT_PATH", "WEBSITE_AUTH_DEFAULT_PROVIDER"};
+    "WEBSITE_AUTH_CLIENT_SECRET", "WEBSITE_AUTH_LOGOUT_PATH", "WEBSITE_AUTH_DEFAULT_PROVIDER",
+    "WEBSITE_AUTH_API_PREFIX"
+};
 
     string[] importantHeaders = new string[] { "X-MS-TOKEN-AAD-ID-TOKEN", "X-MS-CLIENT-PRINCIPAL-IDP", "X-MS-TOKEN-AAD-ACCESS-TOKEN" };
 }