From d685b970aaef6ef293f58ef7add9595a8fa147ec Mon Sep 17 00:00:00 2001
From: Joe DeCock <josephdecock@gmail.com>
Date: Tue, 3 Dec 2024 14:47:27 -0600
Subject: [PATCH] Embed feature mask value into LicenseFeatures

---
 .../Licensing/v2/FeatureManager.cs            |  5 ++--
 src/IdentityServer/Licensing/v2/License.cs    |  6 ++---
 .../Licensing/v2/LicenseFeature.cs            | 27 ++++++++-----------
 3 files changed, 16 insertions(+), 22 deletions(-)

diff --git a/src/IdentityServer/Licensing/v2/FeatureManager.cs b/src/IdentityServer/Licensing/v2/FeatureManager.cs
index 9ea7fb8fe..7594f4743 100644
--- a/src/IdentityServer/Licensing/v2/FeatureManager.cs
+++ b/src/IdentityServer/Licensing/v2/FeatureManager.cs
@@ -28,7 +28,7 @@ public IEnumerable<LicenseFeature> UsedFeatures()
     {
         foreach (LicenseFeature feature in Enum.GetValues<LicenseFeature>())
         {
-            if ((_usedFeatures & feature.ToFeatureMask()) != 0)
+            if ((_usedFeatures & (ulong) feature) != 0)
             {
                 yield return feature;
             }
@@ -52,8 +52,7 @@ public void UseFeature(LicenseFeature feature)
                 }
             }
         }
-        // TODO - refactor the feature so that its value is already the feature mask
-        var featureMask = feature.ToFeatureMask();
+        var featureMask = (ulong) feature;
         Interlocked.Or(ref _usedFeatures, featureMask);
     }
 
diff --git a/src/IdentityServer/Licensing/v2/License.cs b/src/IdentityServer/Licensing/v2/License.cs
index e606180c2..07802b2d8 100644
--- a/src/IdentityServer/Licensing/v2/License.cs
+++ b/src/IdentityServer/Licensing/v2/License.cs
@@ -121,7 +121,7 @@ internal License(ClaimsPrincipal claims)
     /// <returns></returns>
     public bool IsEnabled(LicenseFeature feature)
     {
-        return !IsConfigured || (AllowedFeatureMask & feature.ToFeatureMask()) != 0;
+        return !IsConfigured || (AllowedFeatureMask & (ulong) feature) != 0;
     }
 
     
@@ -136,7 +136,7 @@ private ulong AllowedFeatureMask
                 foreach (var featureClaim in Features)
                 {
                     var feature = ToFeatureEnum(featureClaim);
-                    features |= feature.ToFeatureMask();
+                    features |= (ulong) feature;
                 }
 
                 _allowedFeatureMask = features;
@@ -202,7 +202,7 @@ private ulong FeatureMaskForFeatures(params LicenseFeature[] licenseFeatures)
         var result = 0UL;
         foreach(var feature in licenseFeatures)
         {
-            result |= feature.ToFeatureMask();
+            result |= (ulong) feature;
         }
         return result;
     }
diff --git a/src/IdentityServer/Licensing/v2/LicenseFeature.cs b/src/IdentityServer/Licensing/v2/LicenseFeature.cs
index 491da6867..5ad734161 100644
--- a/src/IdentityServer/Licensing/v2/LicenseFeature.cs
+++ b/src/IdentityServer/Licensing/v2/LicenseFeature.cs
@@ -9,70 +9,65 @@ namespace Duende.IdentityServer.Licensing.v2;
 /// <summary>
 /// The features of IdentityServer that can be enabled or disabled through the License.
 /// </summary>
-public enum LicenseFeature
+public enum LicenseFeature : ulong
 {
     /// <summary>
     /// Automatic Key Management
     /// </summary>
     [Description("key_management")]
-    KeyManagement,
+    KeyManagement = 1,
 
     /// <summary>
     /// Pushed Authorization Requests
     /// </summary>
     [Description("par")]
-    PAR,
+    PAR = 2,
  
     /// <summary>
     /// Resource Isolation
     /// </summary>
     [Description("resource_isolation")]
-    ResourceIsolation,
+    ResourceIsolation = 4,
  
     /// <summary>
     /// Dyanmic External Providers
     /// </summary>
     [Description("dynamic_providers")]
-    DynamicProviders,
+    DynamicProviders = 8,
 
     /// <summary>
     /// Client Initiated Backchannel Authorization
     /// </summary>
     [Description("ciba")]
-    CIBA,
+    CIBA = 16,
 
     /// <summary>
     /// Server-Side Sessions
     /// </summary>
     [Description("server_side_sessions")]
-    ServerSideSessions,
+    ServerSideSessions = 32,
 
     /// <summary>
     /// Demonstrating Proof of Possesion
     /// </summary>
     [Description("dpop")]
-    DPoP,
+    DPoP = 64,
 
     /// <summary>
     /// Configuration API
     /// </summary>
     [Description("config_api")]
-    DCR,
+    DCR = 128,
     
     /// <summary>
     /// ISV (same as Redistribution)
     /// </summary>
     [Description("isv")]
-    ISV,
+    ISV = 256,
     
     /// <summary>
     /// Dedistribution
     /// </summary>
     [Description("redistribution")]
-    Redistribution,
+    Redistribution = 512,
 }
-
-internal static class LicenseFeatureExtensions
-{
-    internal static ulong ToFeatureMask(this LicenseFeature feature) => 1UL << (int) feature;
-}
\ No newline at end of file