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 !MOONLIGHT
  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 [ComVisible (true)]
  46 public sealed class Hash : ISerializable, IBuiltInEvidence {
  47
  48         private Assembly assembly;
  49         private byte[] data;
  50
  51         internal byte[] _md5;
  52         internal byte[] _sha1;
  53
  54         public Hash (Assembly assembly)
  55         {
  56                 if (assembly == null)
  57                         throw new ArgumentNullException ("assembly");
  58                 this.assembly = assembly;
  59         }
  60
  61         internal Hash ()
  62         {
  63         }
  64
  65         internal Hash (SerializationInfo info, StreamingContext context)
  66         {
  67                 data = (byte[]) info.GetValue ("RawData", typeof (byte[]));
  68         }
  69
  70         //
  71         // Public Properties
  72         //
  73
  74         public byte[] MD5 {
  75                 get {
  76                         // Case 1: we have a MD5 value - either precalculated or static (FX 2.0)
  77                         if (_md5 != null)
  78                                 return _md5;
  79
  80                         // Case 2: we don't have a MD5 value precalculated so we either
  81                         // (a): have an assembly reference - and can calculate the hash; or
  82                         // (b): have been initialized with a static MD5 value (FX 2.0)
  83                         if ((assembly == null) && (_sha1 != null)) {
  84                                 string msg = Locale.GetText ("No assembly data. This instance was initialized with an MSHA1 digest value.");
  85                                 throw new SecurityException (msg);
  86                         }
  87                         // fully named to avoid conflit between MD5 property and class name
  88                         HashAlgorithm hash = System.Security.Cryptography.MD5.Create ();
  89                         _md5 = GenerateHash (hash);
  90                         return _md5;
  91                 }
  92         }
  93
  94         public byte[] SHA1 {
  95                 get {
  96                         // Case 1: we have a SHA1 value - either precalculated or static (FX 2.0)
  97                         if (_sha1 != null)
  98                                 return _sha1;
  99
 100                         // Case 2: we don't have a SHA1 value precalculated so we either
 101                         // (a): have an assembly reference - and can calculate the hash; or
 102                         // (b): have been initialized with a static MD5 value (FX 2.0)
 103                         if ((assembly == null) && (_md5 != null)) {
 104                                 string msg = Locale.GetText ("No assembly data. This instance was initialized with an MD5 digest value.");
 105                                 throw new SecurityException (msg);
 106                         }
 107                         // fully named to avoid conflit between SHA1 property and class name
 108                         HashAlgorithm hash = System.Security.Cryptography.SHA1.Create ();
 109                         _sha1 = GenerateHash (hash);
 110                         return _sha1;
 111                 }
 112         }
 113
 114         //
 115         // Public Methods
 116         //
 117
 118         public byte[] GenerateHash (HashAlgorithm hashAlg)
 119         {
 120                 if (hashAlg == null)
 121                         throw new ArgumentNullException ("hashAlg");
 122                 return hashAlg.ComputeHash (GetData ());
 123         }
 124
 125         public void GetObjectData (SerializationInfo info, StreamingContext context)
 126         {
 127                 if (info == null)
 128                         throw new ArgumentNullException ("info");
 129                 info.AddValue ("RawData", GetData ());
 130         }
 131
 132         public override string ToString ()
 133         {
 134                 SecurityElement se = new SecurityElement (GetType ().FullName);
 135                 se.AddAttribute ("version", "1");
 136
 137                 StringBuilder sb = new StringBuilder ();
 138                 byte[] raw = GetData ();
 139                 for (int i=0; i < raw.Length; i++)
 140                         sb.Append (raw [i].ToString ("X2"));
 141
 142                 se.AddChild (new SecurityElement ("RawData", sb.ToString ()));
 143                 return se.ToString ();
 144         }
 145
 146         //
 147         // Private Methods
 148         //
 149
 150         // FIXME: be more restrictive when imperative security is implemented
 151         [FileIOPermission (SecurityAction.Assert, Unrestricted = true)]
 152         private byte[] GetData ()
 153         {
 154                 if ((assembly == null) && (data == null)) {
 155                         string msg = Locale.GetText ("No assembly data.");
 156                         throw new SecurityException (msg);
 157                 }
 158                 if (null == data) {
 159                         // TODO (Pre-Fx-2.0) we mustn't hash the complete assembly!
 160                         // ---- Look at ToString (MS version) for what to hash (and what not to)
 161                         // TODO we must drop the authenticode signature (if present)
 162                         FileStream stream = new
 163                                 FileStream (assembly.Location, FileMode.Open, FileAccess.Read);
 164                         data = new byte [stream.Length];
 165                         stream.Read (data, 0, (int)stream.Length);
 166                 }
 167
 168                 return data;
 169         }
 170
 171         // interface IBuiltInEvidence
 172
 173         int IBuiltInEvidence.GetRequiredSize (bool verbose)
 174         {
 175                 return (verbose ? 5 : 0);       // as documented
 176         }
 177
 178         [MonoTODO ("IBuiltInEvidence")]
 179         int IBuiltInEvidence.InitFromBuffer (char [] buffer, int position)
 180         {
 181                 return 0;
 182         }
 183
 184         [MonoTODO ("IBuiltInEvidence")]
 185         int IBuiltInEvidence.OutputToBuffer (char [] buffer, int position, bool verbose)
 186         {
 187                 return 0;
 188         }
 189
 190         static public Hash CreateMD5 (byte[] md5)
 191         {
 192                 if (md5 == null)
 193                         throw new ArgumentNullException ("md5");
 194                 Hash h = new Hash ();
 195                 h._md5 = md5;
 196                 return h;
 197         }
 198
 199         static public Hash CreateSHA1 (byte[] sha1)
 200         {
 201                 if (sha1 == null)
 202                         throw new ArgumentNullException ("sha1");
 203                 Hash h = new Hash ();
 204                 h._sha1 = sha1;
 205                 return h;
 206         }
 207 }
 208
 209 }
 210
 211 #endif
 212