mcs/class/Mono.Security.Win32/Mono.Security.Cryptography/CapiHash.cs

   1 //
   2 // Mono.Security.Cryptography.CapiHash
   3 //
   4 // Authors:
   5 //      Sebastien Pouliot (sebastien@ximian.com)
   6 //
   7 // Copyright (C) 2003 Motus Technologies Inc. (http://www.motus.com)
   8 // Copyright (C) 2004 Novell (http://www.novell.com)
   9 //
  10
  11 using System;
  12 using System.Security.Cryptography;
  13
  14 namespace Mono.Security.Cryptography {
  15
  16 public class CapiHash : IDisposable {
  17
  18         private CapiContext context;
  19         private IntPtr handle;
  20         private uint hashSize;
  21
  22         public CapiHash (int hashAlgorithm)
  23         {
  24                 context = new CapiContext ();
  25                 Initialize (hashAlgorithm);
  26         }
  27
  28         public CapiHash (CapiContext ctx, int hashAlgorithm)
  29         {
  30                 context = ctx;
  31                 Initialize (hashAlgorithm);
  32         }
  33
  34         public CapiHash (CspParameters cspParams, int hashAlgorithm)
  35         {
  36                 context = new CapiContext (cspParams);
  37                 Initialize (hashAlgorithm);
  38         }
  39
  40         ~CapiHash ()
  41         {
  42                 Dispose ();
  43         }
  44
  45         public IntPtr Handle {
  46                 get { return handle; }
  47         }
  48
  49         public int HashSize {
  50                 get { return (int) hashSize; }
  51         }
  52
  53         public void Initialize (int algo)
  54         {
  55                 if (context != null) {
  56                         context.InternalResult = CryptoAPI.CryptCreateHash (context.Handle, (uint)algo, IntPtr.Zero, 0, ref handle);
  57                         hashSize = 0;
  58                         if (context.Result)
  59                                 context.InternalResult = CryptoAPI.CryptGetHashParam (handle, CryptoAPI.HP_HASHVAL, null, ref hashSize, 0);
  60                         GC.KeepAlive (this);
  61                 }
  62         }
  63
  64         public void Dispose ()
  65         {
  66                 if (handle != IntPtr.Zero) {
  67                         CryptoAPI.CryptDestroyHash (handle);
  68                         context.Dispose ();
  69                         GC.KeepAlive (this);
  70                         handle = IntPtr.Zero;
  71                         GC.SuppressFinalize (this);
  72                 }
  73         }
  74
  75         // FIXME: calling this function 1,000,000 times (with a single character)
  76         // is a good way to lose time (and hung NUnit)
  77         // TODO: find the bug that hang NUnit
  78         // TODO: optimize the function to call CryptHashData less often (bufferize)
  79         public void HashCore (byte[] data, int start, int length)
  80         {
  81                 byte[] toBeHashed = data;
  82                 if (start != 0) {
  83                         toBeHashed = new byte [length];
  84                         Array.Copy (data, start, toBeHashed, 0, length);
  85                 }
  86                 context.InternalResult = CryptoAPI.CryptHashData (handle, toBeHashed, (uint)length, 0);
  87                 GC.KeepAlive (this);
  88         }
  89
  90         public byte[] HashFinal ()
  91         {
  92                 byte[] hash = new byte [hashSize];
  93                 context.InternalResult = CryptoAPI.CryptGetHashParam (handle, CryptoAPI.HP_HASHVAL, hash, ref hashSize, 0);
  94                 GC.KeepAlive (this);
  95                 return hash;
  96         }
  97 }
  98
  99 }