Enable nullable on DataProtection (#28583)

Author: JamesNK

eng/targets/CSharp.Common.targets

@@ -77,8 +77,10 @@
         by compiling the annotations (as internal types).
         The code block that follows sets it up so projects in this repo that target ns2.0 or netfx can compile when Nullable is configured.
         Based on https://github.com/dotnet/runtime/blob/93b6c449d4f31ddd7d573d1d3769e681d5ebceb9/src/libraries/Directory.Build.targets#L215-L222
+
+        SuppressNullableAttributesImport to disable. Used when attributes are already present from another project because of InternalsVisibleTo.
      -->
-    <When Condition="'$(Nullable)' != '' AND ('$(TargetFrameworkIdentifier)' == '.NETStandard' OR '$(TargetFrameworkIdentifier)' == '.NETFramework')">
+    <When Condition="'$(Nullable)' != '' AND '$(SuppressNullableAttributesImport)' != 'true' AND ('$(TargetFrameworkIdentifier)' == '.NETStandard' OR '$(TargetFrameworkIdentifier)' == '.NETFramework')">
       <PropertyGroup>
         <DefineConstants>$(DefineConstants),INTERNAL_NULLABLE_ATTRIBUTES</DefineConstants>
         <NoWarn>$(NoWarn);nullable</NoWarn>

src/DataProtection/Abstractions/src/Infrastructure/IApplicationDiscriminator.cs

@@ -20,6 +20,6 @@ public interface IApplicationDiscriminator
         /// An identifier that uniquely discriminates this application from all other
         /// applications on the machine.
         /// </summary>
-        string Discriminator { get; }
+        string? Discriminator { get; }
     }
 }

src/DataProtection/Abstractions/src/PublicAPI.Shipped.txt

@@ -6,7 +6,7 @@ Microsoft.AspNetCore.DataProtection.IDataProtector
 Microsoft.AspNetCore.DataProtection.IDataProtector.Protect(byte[]! plaintext) -> byte[]!
 Microsoft.AspNetCore.DataProtection.IDataProtector.Unprotect(byte[]! protectedData) -> byte[]!
 Microsoft.AspNetCore.DataProtection.Infrastructure.IApplicationDiscriminator
-Microsoft.AspNetCore.DataProtection.Infrastructure.IApplicationDiscriminator.Discriminator.get -> string!
+Microsoft.AspNetCore.DataProtection.Infrastructure.IApplicationDiscriminator.Discriminator.get -> string?
 static Microsoft.AspNetCore.DataProtection.DataProtectionCommonExtensions.CreateProtector(this Microsoft.AspNetCore.DataProtection.IDataProtectionProvider! provider, System.Collections.Generic.IEnumerable<string!>! purposes) -> Microsoft.AspNetCore.DataProtection.IDataProtector!
 static Microsoft.AspNetCore.DataProtection.DataProtectionCommonExtensions.CreateProtector(this Microsoft.AspNetCore.DataProtection.IDataProtectionProvider! provider, string! purpose, params string![]! subPurposes) -> Microsoft.AspNetCore.DataProtection.IDataProtector!
 static Microsoft.AspNetCore.DataProtection.DataProtectionCommonExtensions.GetDataProtectionProvider(this System.IServiceProvider! services) -> Microsoft.AspNetCore.DataProtection.IDataProtectionProvider!

src/DataProtection/Cryptography.Internal/src/Cng/CachedAlgorithmHandles.cs

@@ -75,7 +75,7 @@ private static BCryptAlgorithmHandle GetSP800_108_CTR_HMACAlgorithm()
         // Warning: mutable struct!
         private struct CachedAlgorithmInfo
         {
-            private WeakReference<BCryptAlgorithmHandle> _algorithmHandle;
+            private WeakReference<BCryptAlgorithmHandle>? _algorithmHandle;
             private readonly Func<BCryptAlgorithmHandle> _factory;
 
             public CachedAlgorithmInfo(Func<BCryptAlgorithmHandle> factory)

src/DataProtection/Cryptography.Internal/src/Cng/OSVersionUtil.cs

@@ -13,7 +13,7 @@ internal static class OSVersionUtil
         private static OSVersion GetOSVersion()
         {
             const string BCRYPT_LIB = "bcrypt.dll";
-            SafeLibraryHandle bcryptLibHandle = null;
+            SafeLibraryHandle? bcryptLibHandle = null;
             try
             {
                 bcryptLibHandle = SafeLibraryHandle.Open(BCRYPT_LIB);

src/DataProtection/Cryptography.Internal/src/Microsoft.AspNetCore.Cryptography.Internal.csproj

@@ -7,7 +7,7 @@
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     <GenerateDocumentationFile>true</GenerateDocumentationFile>
     <PackageTags>aspnetcore;dataprotection</PackageTags>
-    <Nullable>annotations</Nullable>
+    <Nullable>enable</Nullable>
   </PropertyGroup>
 
 </Project>

src/DataProtection/Cryptography.Internal/src/SafeHandles/BCryptAlgorithmHandle.cs

@@ -130,7 +130,7 @@ public uint GetHashDigestLength()
             return digestLength;
         }
 
-        public static BCryptAlgorithmHandle OpenAlgorithmHandle(string algorithmId, string implementation = null, bool hmac = false)
+        public static BCryptAlgorithmHandle OpenAlgorithmHandle(string algorithmId, string? implementation = null, bool hmac = false)
         {
             // from bcrypt.h
             const uint BCRYPT_ALG_HANDLE_HMAC_FLAG = 0x00000008;
@@ -161,7 +161,7 @@ protected override bool ReleaseHandle()
 
         public void SetChainingMode(string chainingMode)
         {
-            fixed (char* pszChainingMode = chainingMode ?? String.Empty)
+            fixed (char* pszChainingMode = chainingMode)
             {
                 SetProperty(Constants.BCRYPT_CHAINING_MODE, pszChainingMode, checked((uint)(chainingMode.Length + 1 /* null terminator */) * sizeof(char)));
             }

src/DataProtection/Cryptography.Internal/src/SafeHandles/BCryptHashHandle.cs

@@ -8,7 +8,7 @@ namespace Microsoft.AspNetCore.Cryptography.SafeHandles
 {
     internal unsafe sealed class BCryptHashHandle : BCryptHandle
     {
-        private BCryptAlgorithmHandle _algProviderHandle;
+        private BCryptAlgorithmHandle? _algProviderHandle;
 
         // Called by P/Invoke when returning SafeHandles
         private BCryptHashHandle() { }

src/DataProtection/Cryptography.Internal/src/SafeHandles/BCryptKeyHandle.cs

@@ -7,7 +7,7 @@ namespace Microsoft.AspNetCore.Cryptography.SafeHandles
 {
     internal sealed class BCryptKeyHandle : BCryptHandle
     {
-        private BCryptAlgorithmHandle _algProviderHandle;
+        private BCryptAlgorithmHandle? _algProviderHandle;
 
         // Called by P/Invoke when returning SafeHandles
         private BCryptKeyHandle() { }

src/DataProtection/Cryptography.Internal/src/SafeHandles/SafeLibraryHandle.cs

@@ -2,6 +2,7 @@
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System;
+using System.Diagnostics.CodeAnalysis;
 using System.Runtime.ConstrainedExecution;
 using System.Runtime.InteropServices;
 using System.Security;
@@ -49,7 +50,7 @@ public void ForbidUnload()
         /// <summary>
         /// Formats a message string using the resource table in the specified library.
         /// </summary>
-        public string FormatMessage(int messageId)
+        public string? FormatMessage(int messageId)
         {
             // from winbase.h
             const uint FORMAT_MESSAGE_ALLOCATE_BUFFER = 0x00000100;
@@ -72,7 +73,7 @@ public string FormatMessage(int messageId)
                 // Successfully retrieved the message.
                 using (messageHandle)
                 {
-                    return new String((char*)messageHandle.DangerousGetHandle(), 0, numCharsOutput).Trim();
+                    return new string((char*)messageHandle.DangerousGetHandle(), 0, numCharsOutput).Trim();
                 }
             }
             else
@@ -85,7 +86,7 @@ public string FormatMessage(int messageId)
         /// <summary>
         /// Gets a delegate pointing to a given export from this library.
         /// </summary>
-        public TDelegate GetProcAddress<TDelegate>(string lpProcName, bool throwIfNotFound = true) where TDelegate : class
+        public TDelegate? GetProcAddress<TDelegate>(string lpProcName, bool throwIfNotFound = true) where TDelegate : class
         {
             IntPtr pfnProc = UnsafeNativeMethods.GetProcAddress(this, lpProcName);
             if (pfnProc == IntPtr.Zero)
@@ -168,11 +169,14 @@ internal static extern SafeLibraryHandle LoadLibraryEx(
                 [In] IntPtr hFile,
                 [In] uint dwFlags);
 
+#pragma warning disable CS8763 // A method marked [DoesNotReturn] should not return.
+            [DoesNotReturn]
             internal static void ThrowExceptionForLastWin32Error()
             {
                 int hr = Marshal.GetHRForLastWin32Error();
                 Marshal.ThrowExceptionForHR(hr);
             }
+#pragma warning restore CS8763 // A method marked [DoesNotReturn] should not return.
         }
     }
 }