class/corlib/System.Security.Policy/Hash.cs

   1 //
   2 // System.Security.Policy.Hash
   3 //
   4 // Authors:
   5 //      Jackson Harper (Jackson@LatitudeGeo.com)
   6 //      Sebastien Pouliot  <sebastien@ximian.com>
   7 //
   8 // (C) 2002 Jackson Harper, All rights reserved.
   9 // Portions (C) 2002 Motus Technologies Inc. (http://www.motus.com)
  10 // Copyright (C) 2004-2005 Novell, Inc (http://www.novell.com)
  11 //
  12 // Permission is hereby granted, free of charge, to any person obtaining
  13 // a copy of this software and associated documentation files (the
  14 // "Software"), to deal in the Software without restriction, including
  15 // without limitation the rights to use, copy, modify, merge, publish,
  16 // distribute, sublicense, and/or sell copies of the Software, and to
  17 // permit persons to whom the Software is furnished to do so, subject to
  18 // the following conditions:
  19 //
  20 // The above copyright notice and this permission notice shall be
  21 // included in all copies or substantial portions of the Software.
  22 //
  23 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  24 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  25 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  26 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  27 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  28 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  29 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  30 //
  31
  32 #if !NET_2_1 || MONOTOUCH
  33
  34 using System.IO;
  35 using System.Reflection;
  36 using System.Runtime.InteropServices;
  37 using System.Runtime.Serialization;
  38 using System.Security.Cryptography;
  39 using System.Security.Permissions;
  40 using System.Text;
  41
  42 namespace System.Security.Policy {
  43
  44 [Serializable]
  45 #if NET_2_0
  46 [ComVisible (true)]
  47 #else
  48 [MonoTODO ("(1.x) This doesn't match the MS version perfectly.")]
  49 // but it does seems to works exactly like Fx 2.0 beta 1 (and beta2 too) !?!?!
  50 #endif
  51 public sealed class Hash : ISerializable, IBuiltInEvidence {
  52
  53         private Assembly assembly;
  54         private byte[] data;
  55
  56         internal byte[] _md5;
  57         internal byte[] _sha1;
  58
  59         public Hash (Assembly assembly)
  60         {
  61                 if (assembly == null)
  62                         throw new ArgumentNullException ("assembly");
  63                 this.assembly = assembly;
  64         }
  65
  66         internal Hash ()
  67         {
  68         }
  69
  70         internal Hash (SerializationInfo info, StreamingContext context)
  71         {
  72                 data = (byte[]) info.GetValue ("RawData", typeof (byte[]));
  73         }
  74
  75         //
  76         // Public Properties
  77         //
  78
  79         public byte[] MD5 {
  80                 get {
  81                         // Case 1: we have a MD5 value - either precalculated or static (FX 2.0)
  82                         if (_md5 != null)
  83                                 return _md5;
  84
  85                         // Case 2: we don't have a MD5 value precalculated so we either
  86                         // (a): have an assembly reference - and can calculate the hash; or
  87                         // (b): have been initialized with a static MD5 value (FX 2.0)
  88 #if NET_2_0
  89                         if ((assembly == null) && (_sha1 != null)) {
  90                                 string msg = Locale.GetText ("No assembly data. This instance was initialized with an MSHA1 digest value.");
  91                                 throw new SecurityException (msg);
  92                         }
  93 #endif
  94                         // fully named to avoid conflit between MD5 property and class name
  95                         HashAlgorithm hash = System.Security.Cryptography.MD5.Create ();
  96                         _md5 = GenerateHash (hash);
  97                         return _md5;
  98                 }
  99         }
 100
 101         public byte[] SHA1 {
 102                 get {
 103                         // Case 1: we have a SHA1 value - either precalculated or static (FX 2.0)
 104                         if (_sha1 != null)
 105                                 return _sha1;
 106
 107                         // Case 2: we don't have a SHA1 value precalculated so we either
 108                         // (a): have an assembly reference - and can calculate the hash; or
 109                         // (b): have been initialized with a static MD5 value (FX 2.0)
 110 #if NET_2_0
 111                         if ((assembly == null) && (_md5 != null)) {
 112                                 string msg = Locale.GetText ("No assembly data. This instance was initialized with an MD5 digest value.");
 113                                 throw new SecurityException (msg);
 114                         }
 115 #endif
 116                         // fully named to avoid conflit between SHA1 property and class name
 117                         HashAlgorithm hash = System.Security.Cryptography.SHA1.Create ();
 118                         _sha1 = GenerateHash (hash);
 119                         return _sha1;
 120                 }
 121         }
 122
 123         //
 124         // Public Methods
 125         //
 126
 127         public byte[] GenerateHash (HashAlgorithm hashAlg)
 128         {
 129                 if (hashAlg == null)
 130                         throw new ArgumentNullException ("hashAlg");
 131                 return hashAlg.ComputeHash (GetData ());
 132         }
 133
 134         public void GetObjectData (SerializationInfo info, StreamingContext context)
 135         {
 136                 if (info == null)
 137                         throw new ArgumentNullException ("info");
 138                 info.AddValue ("RawData", GetData ());
 139         }
 140
 141         public override string ToString ()
 142         {
 143                 SecurityElement se = new SecurityElement (GetType ().FullName);
 144                 se.AddAttribute ("version", "1");
 145
 146                 StringBuilder sb = new StringBuilder ();
 147                 byte[] raw = GetData ();
 148                 for (int i=0; i < raw.Length; i++)
 149                         sb.Append (raw [i].ToString ("X2"));
 150
 151                 se.AddChild (new SecurityElement ("RawData", sb.ToString ()));
 152                 return se.ToString ();
 153         }
 154
 155         //
 156         // Private Methods
 157         //
 158
 159         // FIXME: be more restrictive when imperative security is implemented
 160         [FileIOPermission (SecurityAction.Assert, Unrestricted = true)]
 161         private byte[] GetData ()
 162         {
 163 #if NET_2_0
 164                 if ((assembly == null) && (data == null)) {
 165                         string msg = Locale.GetText ("No assembly data.");
 166                         throw new SecurityException (msg);
 167                 }
 168 #endif
 169                 if (null == data) {
 170                         // TODO (Pre-Fx-2.0) we mustn't hash the complete assembly!
 171                         // ---- Look at ToString (MS version) for what to hash (and what not to)
 172                         // TODO we must drop the authenticode signature (if present)
 173                         FileStream stream = new
 174                                 FileStream (assembly.Location, FileMode.Open, FileAccess.Read);
 175                         data = new byte [stream.Length];
 176                         stream.Read (data, 0, (int)stream.Length);
 177                 }
 178
 179                 return data;
 180         }
 181
 182         // interface IBuiltInEvidence
 183
 184         int IBuiltInEvidence.GetRequiredSize (bool verbose)
 185         {
 186                 return (verbose ? 5 : 0);       // as documented
 187         }
 188
 189         [MonoTODO ("IBuiltInEvidence")]
 190         int IBuiltInEvidence.InitFromBuffer (char [] buffer, int position)
 191         {
 192                 return 0;
 193         }
 194
 195         [MonoTODO ("IBuiltInEvidence")]
 196         int IBuiltInEvidence.OutputToBuffer (char [] buffer, int position, bool verbose)
 197         {
 198                 return 0;
 199         }
 200
 201 #if NET_2_0
 202         static public Hash CreateMD5 (byte[] md5)
 203         {
 204                 if (md5 == null)
 205                         throw new ArgumentNullException ("md5");
 206                 Hash h = new Hash ();
 207                 h._md5 = md5;
 208                 return h;
 209         }
 210
 211         static public Hash CreateSHA1 (byte[] sha1)
 212         {
 213                 if (sha1 == null)
 214                         throw new ArgumentNullException ("sha1");
 215                 Hash h = new Hash ();
 216                 h._sha1 = sha1;
 217                 return h;
 218         }
 219 #endif
 220 }
 221
 222 }
 223
 224 #endif
 225