BCryptSafeHandles.cs source code in C# .NET

Source code for the .NET framework in C#

                        
Code:

                         / 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / fx / src / Core / Microsoft / Win32 / SafeHandles / BCryptSafeHandles.cs / 1305376 / BCryptSafeHandles.cs
                        

                        
                            // ==++== 
//
//   Copyright (c) Microsoft Corporation.  All rights reserved.
//
// ==--== 

using System; 
using System.Runtime.ConstrainedExecution; 
using System.Runtime.InteropServices;
using System.Security; 
using System.Security.Cryptography;
using System.Diagnostics.Contracts;

namespace Microsoft.Win32.SafeHandles { 
    /// 
    ///     SafeHandle representing a BCRYPT_ALG_HANDLE 
    ///  
    // 
    //  
    // 
#pragma warning disable 618    // Have not migrated to v4 transparency yet
    [System.Security.SecurityCritical(System.Security.SecurityCriticalScope.Everything)]
#pragma warning restore 618 
    internal sealed class SafeBCryptAlgorithmHandle : SafeHandleZeroOrMinusOneIsInvalid {
        private SafeBCryptAlgorithmHandle() : base(true) { 
        } 

        [DllImport("bcrypt")] 
        [ReliabilityContract(Consistency.WillNotCorruptState, Cer.Success)]
        [SuppressUnmanagedCodeSecurity]
        private static extern BCryptNative.ErrorCode BCryptCloseAlgorithmProvider(IntPtr hAlgorithm, int flags);
 
        protected override bool ReleaseHandle() {
            return BCryptCloseAlgorithmProvider(handle, 0) == BCryptNative.ErrorCode.Success; 
        } 
    }
 
    /// 
    ///     Safe handle representing a BCRYPT_HASH_HANDLE and the associated buffer holding the hash object
    /// 
    //  
    // 
    //  
#pragma warning disable 618    // Have not migrated to v4 transparency yet 
    [System.Security.SecurityCritical(System.Security.SecurityCriticalScope.Everything)]
#pragma warning restore 618 
    internal sealed class SafeBCryptHashHandle : SafeHandleZeroOrMinusOneIsInvalid {
        private IntPtr m_hashObject;

        private SafeBCryptHashHandle() : base(true) { 
        }
 
        ///  
        ///     Buffer holding the hash object. This buffer should be allocated with Marshal.AllocCoTaskMem.
        ///  
        internal IntPtr HashObject {
            get { return m_hashObject; }

            set { 
                Contract.Requires(value != IntPtr.Zero);
                m_hashObject = value; 
            } 
        }
 

        [DllImport("bcrypt")]
        [ReliabilityContract(Consistency.WillNotCorruptState, Cer.Success)]
        [SuppressUnmanagedCodeSecurity] 
        private static extern BCryptNative.ErrorCode BCryptDestroyHash(IntPtr hHash);
 
        protected override bool ReleaseHandle() { 
            bool success = BCryptDestroyHash(handle) == BCryptNative.ErrorCode.Success;
 
            // The hash object buffer must be released only after destroying the hash handle
            if (m_hashObject != IntPtr.Zero) {
                Marshal.FreeCoTaskMem(m_hashObject);
            } 

            return success; 
        } 
    }
} 

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.

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