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

   1 //
   2 // RSACryptoServiceProvider.cs: Handles an RSA implementation.
   3 //
   4 // Authors:
   5 //      Sebastien Pouliot <sebastien@ximian.com>
   6 //      Ben Maurer (bmaurer@users.sf.net)
   7 //
   8 // (C) 2002, 2003 Motus Technologies Inc. (http://www.motus.com)
   9 // Portions (C) 2003 Ben Maurer
  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 using System.IO;
  33 using System.Runtime.InteropServices;
  34
  35 using Mono.Security.Cryptography;
  36
  37 namespace System.Security.Cryptography {
  38
  39         [ComVisible (true)]
  40         public sealed class RSACryptoServiceProvider : RSA, ICspAsymmetricAlgorithm {
  41                 private const int PROV_RSA_FULL = 1;    // from WinCrypt.h
  42                 private const int AT_KEYEXCHANGE = 1;
  43                 private const int AT_SIGNATURE = 2;
  44
  45                 private KeyPairPersistence store;
  46                 private bool persistKey;
  47                 private bool persisted;
  48
  49                 private bool privateKeyExportable = true;
  50                 private bool m_disposed;
  51
  52                 private RSAManaged rsa;
  53
  54                 public RSACryptoServiceProvider ()
  55                 {
  56                         // Here it's not clear if we need to generate a keypair
  57                         // (note: MS implementation generates a keypair in this case).
  58                         // However we:
  59                         // (a) often use this constructor to import an existing keypair.
  60                         // (b) take a LOT of time to generate the RSA keypair
  61                         // So we'll generate the keypair only when (and if) it's being
  62                         // used (or exported). This should save us a lot of time (at
  63                         // least in the unit tests).
  64                         Common (1024, null);
  65                 }
  66
  67                 public RSACryptoServiceProvider (CspParameters parameters)
  68                 {
  69                         Common (1024, parameters);
  70                         // no keypair generation done at this stage
  71                 }
  72
  73                 public RSACryptoServiceProvider (int dwKeySize)
  74                 {
  75                         // Here it's clear that we need to generate a new keypair
  76                         Common (dwKeySize, null);
  77                         // no keypair generation done at this stage
  78                 }
  79
  80                 public RSACryptoServiceProvider (int dwKeySize, CspParameters parameters)
  81                 {
  82                         Common (dwKeySize, parameters);
  83                         // no keypair generation done at this stage
  84                 }
  85
  86                 private void Common (int dwKeySize, CspParameters p)
  87                 {
  88                         // Microsoft RSA CSP can do between 384 and 16384 bits keypair
  89                         LegalKeySizesValue = new KeySizes [1];
  90                         LegalKeySizesValue [0] = new KeySizes (384, 16384, 8);
  91                         base.KeySize = dwKeySize;
  92
  93                         rsa = new RSAManaged (KeySize);
  94                         rsa.KeyGenerated += new RSAManaged.KeyGeneratedEventHandler (OnKeyGenerated);
  95
  96                         persistKey = (p != null);
  97                         if (p == null) {
  98                                 p = new CspParameters (PROV_RSA_FULL);
  99                                 if (useMachineKeyStore)
 100                                         p.Flags |= CspProviderFlags.UseMachineKeyStore;
 101                                 store = new KeyPairPersistence (p);
 102                                 // no need to load - it cannot exists
 103                         }
 104                         else {
 105                                 store = new KeyPairPersistence (p);
 106                                 bool exists = store.Load ();
 107                                 bool required = (p.Flags & CspProviderFlags.UseExistingKey) != 0;
 108
 109                                 if (required && !exists)
 110                                         throw new CryptographicException ("Keyset does not exist");
 111
 112                                 if (store.KeyValue != null) {
 113                                         persisted = true;
 114                                         this.FromXmlString (store.KeyValue);
 115                                 }
 116                         }
 117                 }
 118
 119                 private static bool useMachineKeyStore;
 120
 121                 public static bool UseMachineKeyStore {
 122                         get { return useMachineKeyStore; }
 123                         set { useMachineKeyStore = value; }
 124                 }
 125
 126                 ~RSACryptoServiceProvider ()
 127                 {
 128                         // Zeroize private key
 129                         Dispose (false);
 130                 }
 131
 132                 public override string KeyExchangeAlgorithm {
 133                         get { return "RSA-PKCS1-KeyEx"; }
 134                 }
 135
 136                 public override int KeySize {
 137                         get {
 138                                 if (rsa == null)
 139                                       return KeySizeValue;
 140                                 else
 141                                       return rsa.KeySize;
 142                         }
 143                 }
 144
 145                 public bool PersistKeyInCsp {
 146                         get { return persistKey; }
 147                         set {
 148                                 persistKey = value;
 149                                 if (persistKey)
 150                                         OnKeyGenerated (rsa, null);
 151                         }
 152                 }
 153
 154                 [ComVisible (false)]
 155                 public bool PublicOnly {
 156                         get { return rsa.PublicOnly; }
 157                 }
 158
 159                 public override string SignatureAlgorithm {
 160                         get { return "http://www.w3.org/2000/09/xmldsig#rsa-sha1"; }
 161                 }
 162
 163                 public byte[] Decrypt (byte[] rgb, bool fOAEP)
 164                 {
 165                         if (m_disposed)
 166                                 throw new ObjectDisposedException ("rsa");
 167                         // choose between OAEP or PKCS#1 v.1.5 padding
 168                         AsymmetricKeyExchangeDeformatter def = null;
 169                         if (fOAEP)
 170                                 def = new RSAOAEPKeyExchangeDeformatter (rsa);
 171                         else
 172                                 def = new RSAPKCS1KeyExchangeDeformatter (rsa);
 173
 174                         return def.DecryptKeyExchange (rgb);
 175                 }
 176
 177                 // NOTE: Unlike MS we need this method
 178                 // LAMESPEC: Not available from MS .NET framework but MS don't tell
 179                 // why! DON'T USE IT UNLESS YOU KNOW WHAT YOU ARE DOING!!! You should
 180                 // only encrypt/decrypt session (secret) key using asymmetric keys.
 181                 // Using this method to decrypt data IS dangerous (and very slow).
 182                 public override byte[] DecryptValue (byte[] rgb)
 183                 {
 184                         if (!rsa.IsCrtPossible)
 185                                 throw new CryptographicException ("Incomplete private key - missing CRT.");
 186
 187                         return rsa.DecryptValue (rgb);
 188                 }
 189
 190                 public byte[] Encrypt (byte[] rgb, bool fOAEP)
 191                 {
 192                         // choose between OAEP or PKCS#1 v.1.5 padding
 193                         AsymmetricKeyExchangeFormatter fmt = null;
 194                         if (fOAEP)
 195                                 fmt = new RSAOAEPKeyExchangeFormatter (rsa);
 196                         else
 197                                 fmt = new RSAPKCS1KeyExchangeFormatter (rsa);
 198
 199                         return fmt.CreateKeyExchange (rgb);
 200                 }
 201
 202                 // NOTE: Unlike MS we need this method
 203                 // LAMESPEC: Not available from MS .NET framework but MS don't tell
 204                 // why! DON'T USE IT UNLESS YOU KNOW WHAT YOU ARE DOING!!! You should
 205                 // only encrypt/decrypt session (secret) key using asymmetric keys.
 206                 // Using this method to encrypt data IS dangerous (and very slow).
 207                 public override byte[] EncryptValue (byte[] rgb)
 208                 {
 209                         return rsa.EncryptValue (rgb);
 210                 }
 211
 212                 public override RSAParameters ExportParameters (bool includePrivateParameters)
 213                 {
 214                         if ((includePrivateParameters) && (!privateKeyExportable))
 215                                 throw new CryptographicException ("cannot export private key");
 216
 217                         return rsa.ExportParameters (includePrivateParameters);
 218                 }
 219
 220                 public override void ImportParameters (RSAParameters parameters)
 221                 {
 222                         rsa.ImportParameters (parameters);
 223                 }
 224
 225                 private HashAlgorithm GetHash (object halg)
 226                 {
 227                         if (halg == null)
 228                                 throw new ArgumentNullException ("halg");
 229
 230                         HashAlgorithm hash = null;
 231                         if (halg is String)
 232                                 hash = HashAlgorithm.Create ((String)halg);
 233                         else if (halg is HashAlgorithm)
 234                                 hash = (HashAlgorithm) halg;
 235                         else if (halg is Type)
 236                                 hash = (HashAlgorithm) Activator.CreateInstance ((Type)halg);
 237                         else
 238                                 throw new ArgumentException ("halg");
 239
 240                         return hash;
 241                 }
 242
 243                 // NOTE: this method can work with ANY configured (OID in machine.config)
 244                 // HashAlgorithm descendant
 245                 public byte[] SignData (byte[] buffer, object halg)
 246                 {
 247                         if (buffer == null)
 248                                 throw new ArgumentNullException ("buffer");
 249                         return SignData (buffer, 0, buffer.Length, halg);
 250                 }
 251
 252                 // NOTE: this method can work with ANY configured (OID in machine.config)
 253                 // HashAlgorithm descendant
 254                 public byte[] SignData (Stream inputStream, object halg)
 255                 {
 256                         HashAlgorithm hash = GetHash (halg);
 257                         byte[] toBeSigned = hash.ComputeHash (inputStream);
 258                         return PKCS1.Sign_v15 (this, hash, toBeSigned);
 259                 }
 260
 261                 // NOTE: this method can work with ANY configured (OID in machine.config)
 262                 // HashAlgorithm descendant
 263                 public byte[] SignData (byte[] buffer, int offset, int count, object halg)
 264                 {
 265                         HashAlgorithm hash = GetHash (halg);
 266                         byte[] toBeSigned = hash.ComputeHash (buffer, offset, count);
 267                         return PKCS1.Sign_v15 (this, hash, toBeSigned);
 268                 }
 269
 270                 private string GetHashNameFromOID (string oid)
 271                 {
 272                         switch (oid) {
 273                         case "1.3.14.3.2.26":
 274                                 return "SHA1";
 275                         case "1.2.840.113549.2.5":
 276                                 return "MD5";
 277                         case "2.16.840.1.101.3.4.2.1":
 278                                 return "SHA256";
 279                         case "2.16.840.1.101.3.4.2.2":
 280                                 return "SHA384";
 281                         case "2.16.840.1.101.3.4.2.3":
 282                                 return "SHA512";
 283                         default:
 284                                 throw new CryptographicException (oid + " is an unsupported hash algorithm for RSA signing");
 285                         }
 286                 }
 287
 288                 public byte[] SignHash (byte[] rgbHash, string str)
 289                 {
 290                         if (rgbHash == null)
 291                                 throw new ArgumentNullException ("rgbHash");
 292                         // Fx 2.0 defaults to the SHA-1
 293                         string hashName = (str == null) ? "SHA1" : GetHashNameFromOID (str);
 294                         HashAlgorithm hash = HashAlgorithm.Create (hashName);
 295                         return PKCS1.Sign_v15 (this, hash, rgbHash);
 296                 }
 297
 298                 // NOTE: this method can work with ANY configured (OID in machine.config)
 299                 // HashAlgorithm descendant
 300                 public bool VerifyData (byte[] buffer, object halg, byte[] signature)
 301                 {
 302                         if (buffer == null)
 303                                 throw new ArgumentNullException ("buffer");
 304                         if (signature == null)
 305                                 throw new ArgumentNullException ("signature");
 306
 307                         HashAlgorithm hash = GetHash (halg);
 308                         byte[] toBeVerified = hash.ComputeHash (buffer);
 309                         return PKCS1.Verify_v15 (this, hash, toBeVerified, signature);
 310                 }
 311
 312                 public bool VerifyHash (byte[] rgbHash, string str, byte[] rgbSignature)
 313                 {
 314                         if (rgbHash == null)
 315                                 throw new ArgumentNullException ("rgbHash");
 316                         if (rgbSignature == null)
 317                                 throw new ArgumentNullException ("rgbSignature");
 318                         // Fx 2.0 defaults to the SHA-1
 319                         string hashName = (str == null) ? "SHA1" : GetHashNameFromOID (str);
 320                         HashAlgorithm hash = HashAlgorithm.Create (hashName);
 321                         return PKCS1.Verify_v15 (this, hash, rgbHash, rgbSignature);
 322                 }
 323
 324                 protected override void Dispose (bool disposing)
 325                 {
 326                         if (!m_disposed) {
 327                                 // the key is persisted and we do not want it persisted
 328                                 if ((persisted) && (!persistKey)) {
 329                                         store.Remove ();        // delete the container
 330                                 }
 331                                 if (rsa != null)
 332                                         rsa.Clear ();
 333                                 // call base class
 334                                 // no need as they all are abstract before us
 335                                 m_disposed = true;
 336                         }
 337                 }
 338
 339                 // private stuff
 340
 341                 private void OnKeyGenerated (object sender, EventArgs e)
 342                 {
 343                         // the key isn't persisted and we want it persisted
 344                         if ((persistKey) && (!persisted)) {
 345                                 // save the current keypair
 346                                 store.KeyValue = this.ToXmlString (!rsa.PublicOnly);
 347                                 store.Save ();
 348                                 persisted = true;
 349                         }
 350                 }
 351                 // ICspAsymmetricAlgorithm
 352
 353                 [ComVisible (false)]
 354                 public CspKeyContainerInfo CspKeyContainerInfo {
 355                         get {
 356                                 return new CspKeyContainerInfo(store.Parameters);
 357                         }
 358                 }
 359
 360                 [ComVisible (false)]
 361                 public byte[] ExportCspBlob (bool includePrivateParameters)
 362                 {
 363                         byte[] blob = null;
 364                         if (includePrivateParameters)
 365                                 blob = CryptoConvert.ToCapiPrivateKeyBlob (this);
 366                         else
 367                                 blob = CryptoConvert.ToCapiPublicKeyBlob (this);
 368
 369                         // ALGID (bytes 4-7) - default is KEYX
 370                         // 00 24 00 00 (for CALG_RSA_SIGN)
 371                         // 00 A4 00 00 (for CALG_RSA_KEYX)
 372                         blob [5] = (byte) (((store != null) && (store.Parameters.KeyNumber == AT_SIGNATURE)) ? 0x24 : 0xA4);
 373                         return blob;
 374                 }
 375
 376                 [ComVisible (false)]
 377                 public void ImportCspBlob (byte[] keyBlob)
 378                 {
 379                         if (keyBlob == null)
 380                                 throw new ArgumentNullException ("keyBlob");
 381
 382                         RSA rsa = CryptoConvert.FromCapiKeyBlob (keyBlob);
 383                         if (rsa is RSACryptoServiceProvider) {
 384                                 // default (if no change are present in machine.config)
 385                                 RSAParameters rsap = rsa.ExportParameters (!(rsa as RSACryptoServiceProvider).PublicOnly);
 386                                 ImportParameters (rsap);
 387                         } else {
 388                                 // we can't know from RSA if the private key is available
 389                                 try {
 390                                         // so we try it...
 391                                         RSAParameters rsap = rsa.ExportParameters (true);
 392                                         ImportParameters (rsap);
 393                                 }
 394                                 catch {
 395                                         // and fall back
 396                                         RSAParameters rsap = rsa.ExportParameters (false);
 397                                         ImportParameters (rsap);
 398                                 }
 399                         }
 400
 401                         var p = new CspParameters (PROV_RSA_FULL);
 402                         p.KeyNumber = keyBlob [5] == 0x24 ? AT_SIGNATURE : AT_KEYEXCHANGE;
 403                         if (useMachineKeyStore)
 404                                 p.Flags |= CspProviderFlags.UseMachineKeyStore;
 405                         store = new KeyPairPersistence (p);
 406                 }
 407         }
 408 }