mcs/class/corlib/System.Security.Cryptography/DSACryptoServiceProvider.cs

   1 //
   2 // System.Security.Cryptography.DSACryptoServiceProvider.cs
   3 //
   4 // Authors:
   5 //      Dan Lewis (dihlewis@yahoo.co.uk)
   6 //      Sebastien Pouliot <sebastien@ximian.com>
   7 //      Ben Maurer (bmaurer@users.sf.net)
   8 //
   9 // (C) 2002
  10 // Portions (C) 2002, 2003 Motus Technologies Inc. (http://www.motus.com)
  11 // Portions (C) 2003 Ben Maurer
  12 // Copyright (C) 2004-2005 Novell, Inc (http://www.novell.com)
  13 //
  14 // Permission is hereby granted, free of charge, to any person obtaining
  15 // a copy of this software and associated documentation files (the
  16 // "Software"), to deal in the Software without restriction, including
  17 // without limitation the rights to use, copy, modify, merge, publish,
  18 // distribute, sublicense, and/or sell copies of the Software, and to
  19 // permit persons to whom the Software is furnished to do so, subject to
  20 // the following conditions:
  21 //
  22 // The above copyright notice and this permission notice shall be
  23 // included in all copies or substantial portions of the Software.
  24 //
  25 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  26 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  27 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  28 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  29 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  30 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  31 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  32 //
  33
  34 #if !MOONLIGHT
  35
  36 using System.IO;
  37 using System.Globalization;
  38 using System.Runtime.InteropServices;
  39
  40 using Mono.Security.Cryptography;
  41
  42 namespace System.Security.Cryptography {
  43
  44         [ComVisible (true)]
  45         public sealed class DSACryptoServiceProvider : DSA, ICspAsymmetricAlgorithm {
  46                 private const int PROV_DSS_DH = 13;             // from WinCrypt.h
  47
  48                 private KeyPairPersistence store;
  49                 private bool persistKey;
  50                 private bool persisted;
  51
  52                 private bool privateKeyExportable = true;
  53                 private bool m_disposed;
  54
  55                 private DSAManaged dsa;
  56
  57                 // MS implementation generates a keypair everytime a new DSA
  58                 // object is created (unless an existing key container is
  59                 // specified in the CspParameters).
  60                 // However we:
  61                 // (a) often use DSA to import an existing keypair.
  62                 // (b) take a LOT of time to generate the DSA group
  63                 // So we'll generate the keypair only when (and if) it's being
  64                 // used (or exported). This should save us a lot of time (at
  65                 // least in the unit tests).
  66
  67                 public DSACryptoServiceProvider ()
  68                         : this (1024, null)
  69                 {
  70                 }
  71
  72                 public DSACryptoServiceProvider (CspParameters parameters)
  73                         : this (1024, parameters)
  74                 {
  75                 }
  76
  77                 public DSACryptoServiceProvider (int dwKeySize)
  78                         : this (dwKeySize, null)
  79                 {
  80                 }
  81
  82                 public DSACryptoServiceProvider (int dwKeySize, CspParameters parameters)
  83                 {
  84                         LegalKeySizesValue = new KeySizes [1];
  85                         LegalKeySizesValue [0] = new KeySizes (512, 1024, 64);
  86
  87                         // will throw an exception is key size isn't supported
  88                         KeySize = dwKeySize;
  89                         dsa = new DSAManaged (dwKeySize);
  90                         dsa.KeyGenerated += new DSAManaged.KeyGeneratedEventHandler (OnKeyGenerated);
  91
  92                         persistKey = (parameters != null);
  93                         if (parameters == null) {
  94                                 parameters = new CspParameters (PROV_DSS_DH);
  95                                 if (useMachineKeyStore)
  96                                         parameters.Flags |= CspProviderFlags.UseMachineKeyStore;
  97                                 store = new KeyPairPersistence (parameters);
  98                                 // no need to load - it cannot exists
  99                         }
 100                         else {
 101                                 store = new KeyPairPersistence (parameters);
 102                                 store.Load ();
 103                                 if (store.KeyValue != null) {
 104                                         persisted = true;
 105                                         this.FromXmlString (store.KeyValue);
 106                                 }
 107                         }
 108                 }
 109
 110                 ~DSACryptoServiceProvider ()
 111                 {
 112                         Dispose (false);
 113                 }
 114
 115                 // DSA isn't used for key exchange
 116                 public override string KeyExchangeAlgorithm {
 117                         get { return null; }
 118                 }
 119
 120                 public override int KeySize {
 121                         get { return dsa.KeySize; }
 122                 }
 123
 124                 public bool PersistKeyInCsp {
 125                         get { return persistKey; }
 126                         set { persistKey = value; }
 127                 }
 128
 129                 [ComVisible (false)]
 130                 public bool PublicOnly {
 131                         get { return dsa.PublicOnly; }
 132                 }
 133
 134                 public override string SignatureAlgorithm {
 135                         get { return "http://www.w3.org/2000/09/xmldsig#dsa-sha1"; }
 136                 }
 137
 138                 private static bool useMachineKeyStore;
 139
 140                 public static bool UseMachineKeyStore {
 141                         get { return useMachineKeyStore; }
 142                         set { useMachineKeyStore = value; }
 143                 }
 144
 145                 public override DSAParameters ExportParameters (bool includePrivateParameters)
 146                 {
 147                         if ((includePrivateParameters) && (!privateKeyExportable)) {
 148                                 throw new CryptographicException (
 149                                         Locale.GetText ("Cannot export private key"));
 150                         }
 151
 152                         return dsa.ExportParameters (includePrivateParameters);
 153                 }
 154
 155                 public override void ImportParameters (DSAParameters parameters)
 156                 {
 157                         dsa.ImportParameters (parameters);
 158                 }
 159
 160                 public override byte[] CreateSignature (byte[] rgbHash)
 161                 {
 162                         return dsa.CreateSignature (rgbHash);
 163                 }
 164
 165                 public byte[] SignData (byte[] buffer)
 166                 {
 167                         // right now only SHA1 is supported by FIPS186-2
 168                         HashAlgorithm hash = SHA1.Create ();
 169                         byte[] toBeSigned = hash.ComputeHash (buffer);
 170                         return dsa.CreateSignature (toBeSigned);
 171                 }
 172
 173                 public byte[] SignData (byte[] buffer, int offset, int count)
 174                 {
 175                         // right now only SHA1 is supported by FIPS186-2
 176                         HashAlgorithm hash = SHA1.Create ();
 177                         byte[] toBeSigned = hash.ComputeHash (buffer, offset, count);
 178                         return dsa.CreateSignature (toBeSigned);
 179                 }
 180
 181                 public byte[] SignData (Stream inputStream)
 182                 {
 183                         // right now only SHA1 is supported by FIPS186-2
 184                         HashAlgorithm hash = SHA1.Create ();
 185                         byte[] toBeSigned = hash.ComputeHash (inputStream);
 186                         return dsa.CreateSignature (toBeSigned);
 187                 }
 188
 189                 public byte[] SignHash (byte[] rgbHash, string str)
 190                 {
 191                         // right now only SHA1 is supported by FIPS186-2
 192                         if (String.Compare (str, "SHA1", true, CultureInfo.InvariantCulture) != 0) {
 193                                 // not documented
 194                                 throw new CryptographicException (Locale.GetText ("Only SHA1 is supported."));
 195                         }
 196
 197                         return dsa.CreateSignature (rgbHash);
 198                 }
 199
 200                 public bool VerifyData (byte[] rgbData, byte[] rgbSignature)
 201                 {
 202                         // right now only SHA1 is supported by FIPS186-2
 203                         HashAlgorithm hash = SHA1.Create();
 204                         byte[] toBeVerified = hash.ComputeHash (rgbData);
 205                         return dsa.VerifySignature (toBeVerified, rgbSignature);
 206                 }
 207
 208                 // LAMESPEC: MD5 isn't allowed with DSA
 209                 public bool VerifyHash (byte[] rgbHash, string str, byte[] rgbSignature)
 210                 {
 211                         if (str == null)
 212                                 str = "SHA1"; // default value
 213                         if (String.Compare (str, "SHA1", true, CultureInfo.InvariantCulture) != 0) {
 214                                 throw new CryptographicException (Locale.GetText ("Only SHA1 is supported."));
 215                         }
 216
 217                         return dsa.VerifySignature (rgbHash, rgbSignature);
 218                 }
 219
 220                 public override bool VerifySignature (byte[] rgbHash, byte[] rgbSignature)
 221                 {
 222                         return dsa.VerifySignature (rgbHash, rgbSignature);
 223                 }
 224
 225                 protected override void Dispose (bool disposing)
 226                 {
 227                         if (!m_disposed) {
 228                                 // the key is persisted and we do not want it persisted
 229                                 if ((persisted) && (!persistKey)) {
 230                                         store.Remove ();        // delete the container
 231                                 }
 232                                 if (dsa != null)
 233                                         dsa.Clear ();
 234                                 // call base class
 235                                 // no need as they all are abstract before us
 236                                 m_disposed = true;
 237                         }
 238                 }
 239
 240                 // private stuff
 241
 242                 private void OnKeyGenerated (object sender, EventArgs e)
 243                 {
 244                         // the key isn't persisted and we want it persisted
 245                         if ((persistKey) && (!persisted)) {
 246                                 // save the current keypair
 247                                 store.KeyValue = this.ToXmlString (!dsa.PublicOnly);
 248                                 store.Save ();
 249                                 persisted = true;
 250                         }
 251                 }
 252                 // ICspAsymmetricAlgorithm
 253
 254                 [MonoTODO ("call into KeyPairPersistence to get details")]
 255                 [ComVisible (false)]
 256                 public CspKeyContainerInfo CspKeyContainerInfo {
 257                         get { return null; }
 258                 }
 259
 260                 [ComVisible (false)]
 261                 public byte[] ExportCspBlob (bool includePrivateParameters)
 262                 {
 263                         byte[] blob = null;
 264                         if (includePrivateParameters)
 265                                 blob = CryptoConvert.ToCapiPrivateKeyBlob (this);
 266                         else
 267                                 blob = CryptoConvert.ToCapiPublicKeyBlob (this);
 268                         return blob;
 269                 }
 270
 271                 [ComVisible (false)]
 272                 public void ImportCspBlob (byte[] keyBlob)
 273                 {
 274                         if (keyBlob == null)
 275                                 throw new ArgumentNullException ("keyBlob");
 276                         DSA dsa = CryptoConvert.FromCapiKeyBlobDSA (keyBlob);
 277                         if (dsa is DSACryptoServiceProvider) {
 278                                 DSAParameters dsap = dsa.ExportParameters (!(dsa as DSACryptoServiceProvider).PublicOnly);
 279                                 ImportParameters (dsap);
 280                         } else {
 281                                 // we can't know from DSA if the private key is available
 282                                 try {
 283                                         // so we try it...
 284                                         DSAParameters dsap = dsa.ExportParameters (true);
 285                                         ImportParameters (dsap);
 286                                 }
 287                                 catch {
 288                                         // and fall back
 289                                         DSAParameters dsap = dsa.ExportParameters (false);
 290                                         ImportParameters (dsap);
 291                                 }
 292                         }
 293                 }
 294         }
 295 }
 296
 297 #endif
 298