Imported Upstream version 4.6.0.125

Former-commit-id: a2155e9bd80020e49e72e86c44da02a8ac0e57a4

mcs/class/referencesource/System.IdentityModel/System/IdentityModel/SafeCryptHandles.cs

@@ -0,0 +1,122 @@
+//-----------------------------------------------------------------------------
+// Copyright (c) Microsoft Corporation.  All rights reserved.
+//-----------------------------------------------------------------------------
+
+namespace System.IdentityModel
+{
+    using System.ComponentModel;
+    using System.Runtime.InteropServices;
+    using System.Runtime.CompilerServices;
+    using System.Runtime.ConstrainedExecution;
+    using System.Security.Cryptography;
+    using System.ServiceModel.Diagnostics;
+    using Microsoft.Win32.SafeHandles;
+
+    class SafeProvHandle : SafeHandleZeroOrMinusOneIsInvalid
+    {
+        SafeProvHandle() : base(true) { }
+
+        // 0 is an Invalid Handle
+        SafeProvHandle(IntPtr handle)
+            : base(true)
+        {
+            DiagnosticUtility.DebugAssert(handle == IntPtr.Zero, "SafeProvHandle constructor can only be called with IntPtr.Zero.");
+            SetHandle(handle);
+        }
+
+        internal static SafeProvHandle InvalidHandle
+        {
+            get { return new SafeProvHandle(IntPtr.Zero); }
+        }
+
+        protected override bool ReleaseHandle()
+        {
+            // PreSharp Bug: Call 'Marshal.GetLastWin32Error' or 'Marshal.GetHRForLastWin32Error' before any other interop call. 
+#pragma warning suppress 56523 // We are not interested in throwing an exception here if CloseHandle fails.
+            return NativeMethods.CryptReleaseContext(handle, 0);
+        }
+    }
+
+    class SafeKeyHandle : SafeHandleZeroOrMinusOneIsInvalid
+    {
+        SafeProvHandle provHandle = null;
+
+        SafeKeyHandle() : base(true) { }
+
+        // 0 is an Invalid Handle
+        SafeKeyHandle(IntPtr handle)
+            : base(true)
+        {
+            DiagnosticUtility.DebugAssert(handle == IntPtr.Zero, "SafeKeyHandle constructor can only be called with IntPtr.Zero.");
+            SetHandle(handle);
+        }
+
+        internal static SafeKeyHandle InvalidHandle
+        {
+            get { return new SafeKeyHandle(IntPtr.Zero); }
+        }
+
+        protected override bool ReleaseHandle()
+        {
+            // PreSharp Bug: Call 'Marshal.GetLastWin32Error' or 'Marshal.GetHRForLastWin32Error' before any other interop call. 
+#pragma warning suppress 56523 // We are not interested in throwing an exception here if CloseHandle fails.
+            bool ret = NativeMethods.CryptDestroyKey(handle);
+            if (this.provHandle != null)
+            {
+                this.provHandle.DangerousRelease();
+                this.provHandle = null;
+            }
+            return ret;
+        }
+
+        internal static unsafe SafeKeyHandle SafeCryptImportKey(SafeProvHandle provHandle, void* pbDataPtr, int cbData)
+        {
+            bool b = false;
+            int err = 0;
+            SafeKeyHandle keyHandle = null;
+            RuntimeHelpers.PrepareConstrainedRegions();
+            try
+            {
+                provHandle.DangerousAddRef(ref b);
+            }
+            catch (Exception e)
+            {
+                if (System.Runtime.Fx.IsFatal(e))
+                    throw;
+                
+                if (b)
+                {
+                    provHandle.DangerousRelease();
+                    b = false;
+                }
+                if (!(e is ObjectDisposedException))
+                    throw;
+            }
+            finally
+            {
+                if (b)
+                {
+                    b = NativeMethods.CryptImportKey(provHandle, pbDataPtr, (uint)cbData, IntPtr.Zero, 0, out keyHandle);
+                    if (!b)
+                    {
+                        err = Marshal.GetLastWin32Error();
+                        provHandle.DangerousRelease();
+                    }
+                    else
+                    {
+                        // Take ownership of AddRef.  Will Release at Close.
+                        keyHandle.provHandle = provHandle;
+                    }
+                }
+            }
+
+            if (!b)
+            {
+                Utility.CloseInvalidOutSafeHandle(keyHandle);
+                string reason = (err != 0) ? new Win32Exception(err).Message : String.Empty;
+                throw DiagnosticUtility.ExceptionUtility.ThrowHelperError(new CryptographicException(SR.GetString(SR.AESCryptImportKeyFailed, reason)));
+            }
+            return keyHandle;
+        }
+    }
+}