Fix dll ref error on Linux.

Author: peombwa

src/Authentication/Authentication/Constants.cs

@@ -15,6 +15,6 @@ public static class Constants
         internal const int MaxDeviceCodeTimeOut = 120; // 2 mins timeout.
         internal const string UserCacheFileName = "userTokenCache.bin3";
         internal const string AppCacheFileName = "appTokenCache.bin3";
-        internal static readonly string TokenCacheDirectory = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.UserProfile), ".Graph");
+        internal static readonly string TokenCacheDirectory = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.UserProfile), ".graph");
     }
 }

src/Authentication/Authentication/Helpers/AuthenticationHelpers.cs

@@ -5,6 +5,7 @@ namespace Microsoft.Graph.PowerShell.Authentication.Helpers
 {
     using Microsoft.Graph.Auth;
     using Microsoft.Graph.PowerShell.Authentication.Models;
+    using Microsoft.Graph.PowerShell.Authentication.TokenCache;
     using Microsoft.Identity.Client;
     using System;
     using System.IO;
@@ -64,7 +65,7 @@ private static void ConfigureTokenCache(ITokenCache tokenCache, string tokenCach
                 lock (FileLock)
                 {
                     args.TokenCache.DeserializeMsalV3(File.Exists(tokenCacheFilePath)
-                        ? TokenCryptoHelpers.DecryptToken(File.ReadAllBytes(tokenCacheFilePath))
+                        ? TokenCryptographer.DecryptToken(File.ReadAllBytes(tokenCacheFilePath))
                         : null,
                         shouldClearExistingCache: true);
                 }
@@ -75,7 +76,7 @@ private static void ConfigureTokenCache(ITokenCache tokenCache, string tokenCach
                 {
                     if (args.HasStateChanged)
                     {
-                        File.WriteAllBytes(tokenCacheFilePath, TokenCryptoHelpers.EncryptToken(args.TokenCache.SerializeMsalV3()));
+                        File.WriteAllBytes(tokenCacheFilePath, TokenCryptographer.EncryptToken(args.TokenCache.SerializeMsalV3()));
                     }
                 }
             });

…entication/Helpers/TokenCryptoHelpers.cs …ication/TokenCache/TokenCryptographer.cssrc/Authentication/Authentication/Helpers/TokenCryptoHelpers.cs renamed to src/Authentication/Authentication/TokenCache/TokenCryptographer.cs src/Authentication/Authentication/Helpers/TokenCryptoHelpers.cs renamed to src/Authentication/Authentication/TokenCache/TokenCryptographer.cs

@@ -1,15 +1,14 @@
 // ------------------------------------------------------------------------------
 //  Copyright (c) Microsoft Corporation.  All Rights Reserved.  Licensed under the MIT License.  See License in the project root for license information.
 // ------------------------------------------------------------------------------
-namespace Microsoft.Graph.PowerShell.Authentication.Helpers
+namespace Microsoft.Graph.PowerShell.Authentication.TokenCache
 {
     using System;
-    using System.Security.Cryptography;
 
     /// <summary>
     /// Helper class to handle token encryption and decryption.
     /// </summary>
-    internal static class TokenCryptoHelpers
+    internal static class TokenCryptographer
     {
         /// <summary>
         /// Encrypts the passed buffer based on the host platform.
@@ -19,7 +18,7 @@ internal static class TokenCryptoHelpers
         public static byte[] EncryptToken(byte[] buffer)
         {
             if (Environment.OSVersion.Platform == PlatformID.Win32NT)
-                return ProtectedData.Protect(buffer, null, DataProtectionScope.CurrentUser);
+                return WindowsTokenCache.EncryptToken(buffer);
             return buffer;
         }
 
@@ -31,7 +30,7 @@ public static byte[] EncryptToken(byte[] buffer)
         public static byte[] DecryptToken(byte[] buffer)
         {
             if (Environment.OSVersion.Platform == PlatformID.Win32NT)
-                return ProtectedData.Unprotect(buffer, null, DataProtectionScope.CurrentUser);
+                return WindowsTokenCache.DecryptToken(buffer);
             return buffer;
         }
     }

src/Authentication/Authentication/TokenCache/WindowsTokenCache.cs

@@ -0,0 +1,30 @@
+// ------------------------------------------------------------------------------
+//  Copyright (c) Microsoft Corporation.  All Rights Reserved.  Licensed under the MIT License.  See License in the project root for license information.
+// ------------------------------------------------------------------------------
+
+namespace Microsoft.Graph.PowerShell.Authentication.TokenCache
+{
+    using System.Security.Cryptography;
+    internal static class WindowsTokenCache
+    {
+        /// <summary>
+        /// Encrypts the passed buffer using Windows DPAPI.
+        /// </summary>
+        /// <param name="buffer">A <see cref="byte[]"/> to encrypt.</param>
+        /// <returns>An encrypted <see cref="byte[]"/>.</returns>
+        public static byte[] EncryptToken(byte[] buffer)
+        {
+            return ProtectedData.Protect(buffer, null, DataProtectionScope.CurrentUser);
+        }
+
+        /// <summary>
+        /// Decrypts the passed buffer Windows DPAPI.
+        /// </summary>
+        /// <param name="buffer">A <see cref="byte[]"/> to decrypt.</param>
+        /// <returns>An decrypted <see cref="byte[]"/>.</returns>
+        public static byte[] DecryptToken(byte[] buffer)
+        {
+            return ProtectedData.Unprotect(buffer, null, DataProtectionScope.CurrentUser);
+        }
+    }
+}