Adding the IAuthenticationSchemeInformationProvider interface

Directory.Build.props

@@ -1,7 +1,7 @@
 <Project>
     <PropertyGroup>
         <!-- This should be passed from the VSTS build -->
-        <MicrosoftIdentityAbstractionsVersion Condition="'$(MicrosoftIdentityAbstractionsVersion)' == ''">9.2.1</MicrosoftIdentityAbstractionsVersion>
+        <MicrosoftIdentityAbstractionsVersion Condition="'$(MicrosoftIdentityAbstractionsVersion)' == ''">9.3.0</MicrosoftIdentityAbstractionsVersion>
         <!-- This will generate AssemblyVersion, AssemblyFileVersion and AssemblyInformationVersion -->
         <Version>$(MicrosoftIdentityAbstractionsVersion)</Version>
         <AssemblyOriginatorKeyFile>$(MSBuildThisFileDirectory)\build\35MSSharedLib1024.snk</AssemblyOriginatorKeyFile>

src/Microsoft.Identity.Abstractions/ApplicationOptions/IAuthenticationSchemeInformationProvider.cs

@@ -0,0 +1,20 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License.
+
+namespace Microsoft.Identity.Abstractions
+{
+    /// <summary>
+    /// Provides information about the effective authentication scheme (options name). 
+    /// If passing null or string.Empty, this returns the default authentication scheme.
+    /// </summary>
+    public interface IAuthenticationSchemeInformationProvider
+    {
+        /// <summary>
+        /// Get the effective authentication scheme based on the provided authentication scheme.
+        /// </summary>
+        /// <param name="authenticationScheme">intended authentication scheme (options name).</param>
+        /// <returns>Effective authentication scheme (default authentication scheme if the intended
+        /// authentication scheme is null or an empty string.</returns>
+        string GetEffectiveAuthenticationScheme(string? authenticationScheme);
+    }
+}