mcs/class/referencesource/mscorlib/system/security/cryptography/safecryptohandles.cs

   1 // ==++==
   2 //
   3 //   Copyright (c) Microsoft Corporation.  All rights reserved.
   4 //
   5 // ==--==
   6 // <OWNER>Microsoft</OWNER>
   7 //
   8
   9 //
  10 // SafeCryptoHandles.cs
  11 //
  12
  13 namespace System.Security.Cryptography {
  14     using System.Runtime.InteropServices;
  15     using System.Runtime.CompilerServices;
  16     using System.Runtime.ConstrainedExecution;
  17     using System.Runtime.Versioning;
  18     using Microsoft.Win32.SafeHandles;
  19
  20     /// <summary>
  21     ///     Safe handle representing a mscorwks!CRYPT_PROV_CTX
  22     /// </summary>
  23     /// <remarks>
  24     ///     Since we need sometimes to delete the key container created in the context of the CSP, the handle
  25     ///     used in this class is actually a pointer to a CRYPT_PROV_CTX unmanaged structure defined in
  26     ///     COMCryptography.h
  27     /// </remarks>
  28     [System.Security.SecurityCritical]  // auto-generated
  29     internal sealed class SafeProvHandle : SafeHandleZeroOrMinusOneIsInvalid {
  30
  31         private SafeProvHandle() : base(true) {
  32             SetHandle(IntPtr.Zero);
  33         }
  34
  35         private SafeProvHandle(IntPtr handle) : base (true) {
  36             SetHandle(handle);
  37         }
  38
  39         internal static SafeProvHandle InvalidHandle {
  40             get { return new SafeProvHandle(); }
  41         }
  42
  43         [DllImport(JitHelpers.QCall, CharSet = CharSet.Unicode)]
  44         [ResourceExposure(ResourceScope.None)]
  45         [ReliabilityContract(Consistency.WillNotCorruptState, Cer.Success)]
  46         [SuppressUnmanagedCodeSecurity]
  47         private static extern void FreeCsp(IntPtr pProviderContext);
  48
  49         [System.Security.SecurityCritical]
  50         protected override bool ReleaseHandle()
  51         {
  52             FreeCsp(handle);
  53             return true;
  54         }
  55     }
  56
  57 #if FEATURE_CRYPTO || FEATURE_LEGACYNETCFCRYPTO
  58     /// <summary>
  59     ///     Safe handle representing a mscorkws!CRYPT_KEY_CTX
  60     /// </summary>
  61     /// <summary>
  62     ///     Since we need to delete the key handle before the provider is released we need to actually hold a
  63     ///     pointer to a CRYPT_KEY_CTX unmanaged structure whose destructor decrements a refCount. Only when
  64     ///     the provider refCount is 0 it is deleted. This way, we loose a ---- in the critical finalization
  65     ///     of the key handle and provider handle. This also applies to hash handles, which point to a
  66     ///     CRYPT_HASH_CTX. Those strucutres are defined in COMCryptography.h
  67     /// </summary>
  68     [System.Security.SecurityCritical]  // auto-generated
  69     internal sealed class SafeKeyHandle : SafeHandleZeroOrMinusOneIsInvalid {
  70
  71         private SafeKeyHandle() : base(true) {
  72             SetHandle(IntPtr.Zero);
  73         }
  74
  75         private SafeKeyHandle(IntPtr handle) : base (true) {
  76             SetHandle(handle);
  77         }
  78
  79         internal static SafeKeyHandle InvalidHandle {
  80             get { return new SafeKeyHandle(); }
  81         }
  82
  83         [DllImport(JitHelpers.QCall, CharSet = CharSet.Unicode)]
  84         [ReliabilityContract(Consistency.WillNotCorruptState, Cer.Success)]
  85         [ResourceExposure(ResourceScope.None)]
  86         [SuppressUnmanagedCodeSecurity]
  87         private static extern void FreeKey(IntPtr pKeyCotext);
  88
  89         [System.Security.SecurityCritical]
  90         protected override bool ReleaseHandle()
  91         {
  92             FreeKey(handle);
  93             return true;
  94         }
  95     }
  96
  97     /// <summary>
  98     ///     SafeHandle representing a mscorwks!CRYPT_HASH_CTX
  99     /// </summary>
 100     /// <remarks>
 101     ///     See code:System.Security.Cryptography.SafeKeyHandle for information about the release process
 102     ///     for a CRYPT_HASH_CTX.
 103     /// </remarks>
 104     [System.Security.SecurityCritical]  // auto-generated
 105     internal sealed class SafeHashHandle : SafeHandleZeroOrMinusOneIsInvalid {
 106
 107         private SafeHashHandle() : base(true) {
 108             SetHandle(IntPtr.Zero);
 109         }
 110
 111         private SafeHashHandle(IntPtr handle) : base (true) {
 112             SetHandle(handle);
 113         }
 114
 115         internal static SafeHashHandle InvalidHandle {
 116             get { return new SafeHashHandle(); }
 117         }
 118
 119         [DllImport(JitHelpers.QCall, CharSet = CharSet.Unicode)]
 120         [ReliabilityContract(Consistency.WillNotCorruptState, Cer.Success)]
 121         [ResourceExposure(ResourceScope.None)]
 122         [SuppressUnmanagedCodeSecurity]
 123         private static extern void FreeHash(IntPtr pHashContext);
 124
 125         [System.Security.SecurityCritical]
 126         protected override bool ReleaseHandle()
 127         {
 128             FreeHash(handle);
 129             return true;
 130         }
 131     }
 132 #endif // #if FEATURE_CRYPTO || FEATURE_LEGACYNETCFCRYPTO
 133 }
 134