转移.net core 3.1，为.NET 5做准备

OpenAuth.Identity/Quickstart/Extensions.cs

@@ -0,0 +1,25 @@
+using System.Threading.Tasks;
+using IdentityServer4.Stores;
+
+namespace OpenAuth.IdentityServer.Quickstart
+{
+    public static class Extensions
+    {
+        /// <summary>
+        /// Determines whether the client is configured to use PKCE.
+        /// </summary>
+        /// <param name="store">The store.</param>
+        /// <param name="client_id">The client identifier.</param>
+        /// <returns></returns>
+        public static async Task<bool> IsPkceClientAsync(this IClientStore store, string client_id)
+        {
+            if (!string.IsNullOrWhiteSpace(client_id))
+            {
+                var client = await store.FindEnabledClientByIdAsync(client_id);
+                return client?.RequirePkce == true;
+            }
+
+            return false;
+        }
+    }
+}