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 #if !MOONLIGHT
  33
  34 using System.IO;
  35 using System.Runtime.InteropServices;
  36
  37 using Mono.Security.Cryptography;
  38
  39 namespace System.Security.Cryptography {
  40
  41         [ComVisible (true)]
  42         public sealed class RSACryptoServiceProvider : RSA, ICspAsymmetricAlgorithm {
  43                 private const int PROV_RSA_FULL = 1;    // from WinCrypt.h
  44                 private const int AT_KEYEXCHANGE = 1;
  45                 private const int AT_SIGNATURE = 2;
  46
  47                 private KeyPairPersistence store;
  48                 private bool persistKey;
  49                 private bool persisted;
  50
  51                 private bool privateKeyExportable = true;
  52                 private bool m_disposed;
  53
  54                 private RSAManaged rsa;
  55
  56                 public RSACryptoServiceProvider ()
  57                 {
  58                         // Here it's not clear if we need to generate a keypair
  59                         // (note: MS implementation generates a keypair in this case).
  60                         // However we:
  61                         // (a) often use this constructor to import an existing keypair.
  62                         // (b) take a LOT of time to generate the RSA keypair
  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                         Common (1024, null);
  67                 }
  68
  69                 public RSACryptoServiceProvider (CspParameters parameters)
  70                 {
  71                         Common (1024, parameters);
  72                         // no keypair generation done at this stage
  73                 }
  74
  75                 public RSACryptoServiceProvider (int dwKeySize)
  76                 {
  77                         // Here it's clear that we need to generate a new keypair
  78                         Common (dwKeySize, null);
  79                         // no keypair generation done at this stage
  80                 }
  81
  82                 public RSACryptoServiceProvider (int dwKeySize, CspParameters parameters)
  83                 {
  84                         Common (dwKeySize, parameters);
  85                         // no keypair generation done at this stage
  86                 }
  87
  88                 private void Common (int dwKeySize, CspParameters p)
  89                 {
  90                         // Microsoft RSA CSP can do between 384 and 16384 bits keypair
  91                         LegalKeySizesValue = new KeySizes [1];
  92                         LegalKeySizesValue [0] = new KeySizes (384, 16384, 8);
  93                         base.KeySize = dwKeySize;
  94
  95                         rsa = new RSAManaged (KeySize);
  96                         rsa.KeyGenerated += new RSAManaged.KeyGeneratedEventHandler (OnKeyGenerated);
  97
  98                         persistKey = (p != null);
  99                         if (p == null) {
 100                                 p = new CspParameters (PROV_RSA_FULL);
 101                                 if (useMachineKeyStore)
 102                                         p.Flags |= CspProviderFlags.UseMachineKeyStore;
 103                                 store = new KeyPairPersistence (p);
 104                                 // no need to load - it cannot exists
 105                         }
 106                         else {
 107                                 store = new KeyPairPersistence (p);
 108                                 bool exists = store.Load ();
 109                                 bool required = (p.Flags & CspProviderFlags.UseExistingKey) != 0;
 110
 111                                 if (required && !exists)
 112                                         throw new CryptographicException ("Keyset does not exist");
 113
 114                                 if (store.KeyValue != null) {
 115                                         persisted = true;
 116                                         this.FromXmlString (store.KeyValue);
 117                                 }
 118                         }
 119                 }
 120
 121                 private static bool useMachineKeyStore;
 122
 123                 public static bool UseMachineKeyStore {
 124                         get { return useMachineKeyStore; }
 125                         set { useMachineKeyStore = value; }
 126                 }
 127
 128                 ~RSACryptoServiceProvider ()
 129                 {
 130                         // Zeroize private key
 131                         Dispose (false);
 132                 }
 133
 134                 public override string KeyExchangeAlgorithm {
 135                         get { return "RSA-PKCS1-KeyEx"; }
 136                 }
 137
 138                 public override int KeySize {
 139                         get {
 140                                 if (rsa == null)
 141                                       return KeySizeValue;
 142                                 else
 143                                       return rsa.KeySize;
 144                         }
 145                 }
 146
 147                 public bool PersistKeyInCsp {
 148                         get { return persistKey; }
 149                         set {
 150                                 persistKey = value;
 151                                 if (persistKey)
 152                                         OnKeyGenerated (rsa, null);
 153                         }
 154                 }
 155
 156                 [ComVisible (false)]
 157                 public bool PublicOnly {
 158                         get { return rsa.PublicOnly; }
 159                 }
 160
 161                 public override string SignatureAlgorithm {
 162                         get { return "http://www.w3.org/2000/09/xmldsig#rsa-sha1"; }
 163                 }
 164
 165                 public byte[] Decrypt (byte[] rgb, bool fOAEP)
 166                 {
 167                         if (m_disposed)
 168                                 throw new ObjectDisposedException ("rsa");
 169                         // choose between OAEP or PKCS#1 v.1.5 padding
 170                         AsymmetricKeyExchangeDeformatter def = null;
 171                         if (fOAEP)
 172                                 def = new RSAOAEPKeyExchangeDeformatter (rsa);
 173                         else
 174                                 def = new RSAPKCS1KeyExchangeDeformatter (rsa);
 175
 176                         return def.DecryptKeyExchange (rgb);
 177                 }
 178
 179                 // NOTE: Unlike MS we need this method
 180                 // LAMESPEC: Not available from MS .NET framework but MS don't tell
 181                 // why! DON'T USE IT UNLESS YOU KNOW WHAT YOU ARE DOING!!! You should
 182                 // only encrypt/decrypt session (secret) key using asymmetric keys.
 183                 // Using this method to decrypt data IS dangerous (and very slow).
 184                 public override byte[] DecryptValue (byte[] rgb)
 185                 {
 186                         if (!rsa.IsCrtPossible)
 187                                 throw new CryptographicException ("Incomplete private key - missing CRT.");
 188
 189                         return rsa.DecryptValue (rgb);
 190                 }
 191
 192                 public byte[] Encrypt (byte[] rgb, bool fOAEP)
 193                 {
 194                         // choose between OAEP or PKCS#1 v.1.5 padding
 195                         AsymmetricKeyExchangeFormatter fmt = null;
 196                         if (fOAEP)
 197                                 fmt = new RSAOAEPKeyExchangeFormatter (rsa);
 198                         else
 199                                 fmt = new RSAPKCS1KeyExchangeFormatter (rsa);
 200
 201                         return fmt.CreateKeyExchange (rgb);
 202                 }
 203
 204                 // NOTE: Unlike MS we need this method
 205                 // LAMESPEC: Not available from MS .NET framework but MS don't tell
 206                 // why! DON'T USE IT UNLESS YOU KNOW WHAT YOU ARE DOING!!! You should
 207                 // only encrypt/decrypt session (secret) key using asymmetric keys.
 208                 // Using this method to encrypt data IS dangerous (and very slow).
 209                 public override byte[] EncryptValue (byte[] rgb)
 210                 {
 211                         return rsa.EncryptValue (rgb);
 212                 }
 213
 214                 public override RSAParameters ExportParameters (bool includePrivateParameters)
 215                 {
 216                         if ((includePrivateParameters) && (!privateKeyExportable))
 217                                 throw new CryptographicException ("cannot export private key");
 218
 219                         return rsa.ExportParameters (includePrivateParameters);
 220                 }
 221
 222                 public override void ImportParameters (RSAParameters parameters)
 223                 {
 224                         rsa.ImportParameters (parameters);
 225                 }
 226
 227                 private HashAlgorithm GetHash (object halg)
 228                 {
 229                         if (halg == null)
 230                                 throw new ArgumentNullException ("halg");
 231
 232                         HashAlgorithm hash = null;
 233                         if (halg is String)
 234                                 hash = HashAlgorithm.Create ((String)halg);
 235                         else if (halg is HashAlgorithm)
 236                                 hash = (HashAlgorithm) halg;
 237                         else if (halg is Type)
 238                                 hash = (HashAlgorithm) Activator.CreateInstance ((Type)halg);
 239                         else
 240                                 throw new ArgumentException ("halg");
 241
 242                         return hash;
 243                 }
 244
 245                 // NOTE: this method can work with ANY configured (OID in machine.config)
 246                 // HashAlgorithm descendant
 247                 public byte[] SignData (byte[] buffer, object halg)
 248                 {
 249                         if (buffer == null)
 250                                 throw new ArgumentNullException ("buffer");
 251                         return SignData (buffer, 0, buffer.Length, halg);
 252                 }
 253
 254                 // NOTE: this method can work with ANY configured (OID in machine.config)
 255                 // HashAlgorithm descendant
 256                 public byte[] SignData (Stream inputStream, object halg)
 257                 {
 258                         HashAlgorithm hash = GetHash (halg);
 259                         byte[] toBeSigned = hash.ComputeHash (inputStream);
 260                         return PKCS1.Sign_v15 (this, hash, toBeSigned);
 261                 }
 262
 263                 // NOTE: this method can work with ANY configured (OID in machine.config)
 264                 // HashAlgorithm descendant
 265                 public byte[] SignData (byte[] buffer, int offset, int count, object halg)
 266                 {
 267                         HashAlgorithm hash = GetHash (halg);
 268                         byte[] toBeSigned = hash.ComputeHash (buffer, offset, count);
 269                         return PKCS1.Sign_v15 (this, hash, toBeSigned);
 270                 }
 271
 272                 private string GetHashNameFromOID (string oid)
 273                 {
 274                         switch (oid) {
 275                         case "1.3.14.3.2.26":
 276                                 return "SHA1";
 277                         case "1.2.840.113549.2.5":
 278                                 return "MD5";
 279                         case "2.16.840.1.101.3.4.2.1":
 280                                 return "SHA256";
 281                         case "2.16.840.1.101.3.4.2.2":
 282                                 return "SHA384";
 283                         case "2.16.840.1.101.3.4.2.3":
 284                                 return "SHA512";
 285                         default:
 286                                 throw new CryptographicException (oid + " is an unsupported hash algorithm for RSA signing");
 287                         }
 288                 }
 289
 290                 public byte[] SignHash (byte[] rgbHash, string str)
 291                 {
 292                         if (rgbHash == null)
 293                                 throw new ArgumentNullException ("rgbHash");
 294                         // Fx 2.0 defaults to the SHA-1
 295                         string hashName = (str == null) ? "SHA1" : GetHashNameFromOID (str);
 296                         HashAlgorithm hash = HashAlgorithm.Create (hashName);
 297                         return PKCS1.Sign_v15 (this, hash, rgbHash);
 298                 }
 299
 300                 // NOTE: this method can work with ANY configured (OID in machine.config)
 301                 // HashAlgorithm descendant
 302                 public bool VerifyData (byte[] buffer, object halg, byte[] signature)
 303                 {
 304                         if (buffer == null)
 305                                 throw new ArgumentNullException ("buffer");
 306                         if (signature == null)
 307                                 throw new ArgumentNullException ("signature");
 308
 309                         HashAlgorithm hash = GetHash (halg);
 310                         byte[] toBeVerified = hash.ComputeHash (buffer);
 311                         return PKCS1.Verify_v15 (this, hash, toBeVerified, signature);
 312                 }
 313
 314                 public bool VerifyHash (byte[] rgbHash, string str, byte[] rgbSignature)
 315                 {
 316                         if (rgbHash == null)
 317                                 throw new ArgumentNullException ("rgbHash");
 318                         if (rgbSignature == null)
 319                                 throw new ArgumentNullException ("rgbSignature");
 320                         // Fx 2.0 defaults to the SHA-1
 321                         string hashName = (str == null) ? "SHA1" : GetHashNameFromOID (str);
 322                         HashAlgorithm hash = HashAlgorithm.Create (hashName);
 323                         return PKCS1.Verify_v15 (this, hash, rgbHash, rgbSignature);
 324                 }
 325
 326                 protected override void Dispose (bool disposing)
 327                 {
 328                         if (!m_disposed) {
 329                                 // the key is persisted and we do not want it persisted
 330                                 if ((persisted) && (!persistKey)) {
 331                                         store.Remove ();        // delete the container
 332                                 }
 333                                 if (rsa != null)
 334                                         rsa.Clear ();
 335                                 // call base class
 336                                 // no need as they all are abstract before us
 337                                 m_disposed = true;
 338                         }
 339                 }
 340
 341                 // private stuff
 342
 343                 private void OnKeyGenerated (object sender, EventArgs e)
 344                 {
 345                         // the key isn't persisted and we want it persisted
 346                         if ((persistKey) && (!persisted)) {
 347                                 // save the current keypair
 348                                 store.KeyValue = this.ToXmlString (!rsa.PublicOnly);
 349                                 store.Save ();
 350                                 persisted = true;
 351                         }
 352                 }
 353                 // ICspAsymmetricAlgorithm
 354
 355                 [ComVisible (false)]
 356                 public CspKeyContainerInfo CspKeyContainerInfo {
 357                         get {
 358                                 return new CspKeyContainerInfo(store.Parameters);
 359                         }
 360                 }
 361
 362                 [ComVisible (false)]
 363                 public byte[] ExportCspBlob (bool includePrivateParameters)
 364                 {
 365                         byte[] blob = null;
 366                         if (includePrivateParameters)
 367                                 blob = CryptoConvert.ToCapiPrivateKeyBlob (this);
 368                         else
 369                                 blob = CryptoConvert.ToCapiPublicKeyBlob (this);
 370
 371                         // ALGID (bytes 4-7) - default is KEYX
 372                         // 00 24 00 00 (for CALG_RSA_SIGN)
 373                         // 00 A4 00 00 (for CALG_RSA_KEYX)
 374                         blob [5] = (byte) (((store != null) && (store.Parameters.KeyNumber == AT_SIGNATURE)) ? 0x24 : 0xA4);
 375                         return blob;
 376                 }
 377
 378                 [ComVisible (false)]
 379                 public void ImportCspBlob (byte[] keyBlob)
 380                 {
 381                         if (keyBlob == null)
 382                                 throw new ArgumentNullException ("keyBlob");
 383
 384                         RSA rsa = CryptoConvert.FromCapiKeyBlob (keyBlob);
 385                         if (rsa is RSACryptoServiceProvider) {
 386                                 // default (if no change are present in machine.config)
 387                                 RSAParameters rsap = rsa.ExportParameters (!(rsa as RSACryptoServiceProvider).PublicOnly);
 388                                 ImportParameters (rsap);
 389                         } else {
 390                                 // we can't know from RSA if the private key is available
 391                                 try {
 392                                         // so we try it...
 393                                         RSAParameters rsap = rsa.ExportParameters (true);
 394                                         ImportParameters (rsap);
 395                                 }
 396                                 catch {
 397                                         // and fall back
 398                                         RSAParameters rsap = rsa.ExportParameters (false);
 399                                         ImportParameters (rsap);
 400                                 }
 401                         }
 402
 403                         var p = new CspParameters (PROV_RSA_FULL);
 404                         p.KeyNumber = keyBlob [5] == 0x24 ? AT_SIGNATURE : AT_KEYEXCHANGE;
 405                         if (useMachineKeyStore)
 406                                 p.Flags |= CspProviderFlags.UseMachineKeyStore;
 407                         store = new KeyPairPersistence (p);
 408                 }
 409         }
 410 }
 411
 412 #endif
 413