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         public partial class RSACryptoServiceProvider {
  40                 private const int PROV_RSA_FULL = 1;    // from WinCrypt.h
  41                 private const int AT_KEYEXCHANGE = 1;
  42                 private const int AT_SIGNATURE = 2;
  43
  44                 private KeyPairPersistence store;
  45                 private bool persistKey;
  46                 private bool persisted;
  47
  48                 private bool privateKeyExportable = true;
  49                 private bool m_disposed;
  50
  51                 private RSAManaged rsa;
  52
  53                 public RSACryptoServiceProvider ()
  54                         : this (1024)
  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                 }
  65
  66                 public RSACryptoServiceProvider (CspParameters parameters)
  67                         : this (1024, parameters)
  68                 {
  69                         // no keypair generation done at this stage
  70                 }
  71
  72                 public RSACryptoServiceProvider (int dwKeySize)
  73                 {
  74                         // Here it's clear that we need to generate a new keypair
  75                         Common (dwKeySize, false);
  76                         // no keypair generation done at this stage
  77                 }
  78
  79                 public RSACryptoServiceProvider (int dwKeySize, CspParameters parameters)
  80                 {
  81                         bool has_parameters = parameters != null;
  82                         Common (dwKeySize, has_parameters);
  83                         if (has_parameters)
  84                                 Common (parameters);
  85                         // no keypair generation done at this stage
  86                 }
  87
  88                 void Common (int dwKeySize, bool parameters)
  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 = parameters;
  99                         if (parameters)
 100                                 return;
 101
 102                         // no need to load - it cannot exists
 103                         var p = new CspParameters (PROV_RSA_FULL);
 104                         if (UseMachineKeyStore)
 105                                 p.Flags |= CspProviderFlags.UseMachineKeyStore;
 106                         store = new KeyPairPersistence (p);
 107                 }
 108
 109                 void Common (CspParameters p)
 110                 {
 111                         store = new KeyPairPersistence (p);
 112                         bool exists = store.Load ();
 113                         bool required = (p.Flags & CspProviderFlags.UseExistingKey) != 0;
 114                         privateKeyExportable = (p.Flags & CspProviderFlags.UseNonExportableKey) == 0;
 115
 116                         if (required && !exists)
 117                                 throw new CryptographicException ("Keyset does not exist");
 118
 119                         if (store.KeyValue != null) {
 120                                 persisted = true;
 121                                 FromXmlString (store.KeyValue);
 122                         }
 123                 }
 124
 125                 ~RSACryptoServiceProvider ()
 126                 {
 127                         // Zeroize private key
 128                         Dispose (false);
 129                 }
 130
 131                 public override string KeyExchangeAlgorithm {
 132                         get { return "RSA-PKCS1-KeyEx"; }
 133                 }
 134
 135                 public override int KeySize {
 136                         get {
 137                                 if (rsa == null)
 138                                       return KeySizeValue;
 139                                 else
 140                                       return rsa.KeySize;
 141                         }
 142                 }
 143
 144                 public bool PersistKeyInCsp {
 145                         get { return persistKey; }
 146                         set {
 147                                 persistKey = value;
 148                                 if (persistKey)
 149                                         OnKeyGenerated (rsa, null);
 150                         }
 151                 }
 152
 153                 [ComVisible (false)]
 154                 public bool PublicOnly {
 155                         get { return rsa.PublicOnly; }
 156                 }
 157
 158                 public byte[] Decrypt (byte[] rgb, bool fOAEP)
 159                 {
 160                         if (rgb == null)
 161                                 throw new ArgumentNullException("rgb");
 162
 163                         // size check -- must be at most the modulus size
 164                         if (rgb.Length > (KeySize / 8))
 165                                 throw new CryptographicException(Environment.GetResourceString("Cryptography_Padding_DecDataTooBig", KeySize / 8));
 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                         var rsaParams = rsa.ExportParameters (includePrivateParameters);
 220                         if (includePrivateParameters) {
 221                                 // we want an ArgumentNullException is only the D is missing, but a
 222                                 // CryptographicException if other parameters (CRT) are missings
 223                                 if (rsaParams.D == null) {
 224                                         throw new ArgumentNullException ("Missing D parameter for the private key.");
 225                                 } else if ((rsaParams.P == null) || (rsaParams.Q == null) || (rsaParams.DP == null) ||
 226                                         (rsaParams.DQ == null) || (rsaParams.InverseQ == null)) {
 227                                         // note: we can import a private key, using FromXmlString,
 228                                         // without the CRT parameters but we export it using ToXmlString!
 229                                         throw new CryptographicException ("Missing some CRT parameters for the private key.");
 230                                 }
 231                         }
 232
 233                         return rsaParams;
 234                 }
 235
 236                 public override void ImportParameters (RSAParameters parameters)
 237                 {
 238                         rsa.ImportParameters (parameters);
 239                 }
 240
 241                 private HashAlgorithm GetHash (object halg)
 242                 {
 243                         if (halg == null)
 244                                 throw new ArgumentNullException ("halg");
 245
 246                         HashAlgorithm hash = null;
 247                         if (halg is String)
 248                                 hash = GetHashFromString ((string) halg);
 249                         else if (halg is HashAlgorithm)
 250                                 hash = (HashAlgorithm) halg;
 251                         else if (halg is Type)
 252                                 hash = (HashAlgorithm) Activator.CreateInstance ((Type)halg);
 253                         else
 254                                 throw new ArgumentException ("halg");
 255
 256                         if (hash == null)
 257                                 throw new ArgumentException (
 258                                                 "Could not find provider for halg='" + halg + "'.",
 259                                                 "halg");
 260
 261                         return hash;
 262                 }
 263
 264                 private HashAlgorithm GetHashFromString (string name)
 265                 {
 266                         HashAlgorithm hash = HashAlgorithm.Create (name);
 267                         if (hash != null)
 268                                 return hash;
 269                         try {
 270                                 return HashAlgorithm.Create (GetHashNameFromOID (name));
 271                         } catch (CryptographicException e) {
 272                                 throw new ArgumentException (e.Message, "halg", e);
 273                         }
 274                 }
 275
 276                 // NOTE: this method can work with ANY configured (OID in machine.config)
 277                 // HashAlgorithm descendant
 278                 public byte[] SignData (byte[] buffer, object halg)
 279                 {
 280                         if (buffer == null)
 281                                 throw new ArgumentNullException ("buffer");
 282                         return SignData (buffer, 0, buffer.Length, halg);
 283                 }
 284
 285                 // NOTE: this method can work with ANY configured (OID in machine.config)
 286                 // HashAlgorithm descendant
 287                 public byte[] SignData (Stream inputStream, object halg)
 288                 {
 289                         HashAlgorithm hash = GetHash (halg);
 290                         byte[] toBeSigned = hash.ComputeHash (inputStream);
 291                         return PKCS1.Sign_v15 (this, hash, toBeSigned);
 292                 }
 293
 294                 // NOTE: this method can work with ANY configured (OID in machine.config)
 295                 // HashAlgorithm descendant
 296                 public byte[] SignData (byte[] buffer, int offset, int count, object halg)
 297                 {
 298                         HashAlgorithm hash = GetHash (halg);
 299                         byte[] toBeSigned = hash.ComputeHash (buffer, offset, count);
 300                         return PKCS1.Sign_v15 (this, hash, toBeSigned);
 301                 }
 302
 303                 private string GetHashNameFromOID (string oid)
 304                 {
 305                         switch (oid) {
 306                         case "1.3.14.3.2.26":
 307                                 return "SHA1";
 308                         case "1.2.840.113549.2.5":
 309                                 return "MD5";
 310                         case "2.16.840.1.101.3.4.2.1":
 311                                 return "SHA256";
 312                         case "2.16.840.1.101.3.4.2.2":
 313                                 return "SHA384";
 314                         case "2.16.840.1.101.3.4.2.3":
 315                                 return "SHA512";
 316                         default:
 317                                 throw new CryptographicException (oid + " is an unsupported hash algorithm for RSA signing");
 318                         }
 319                 }
 320
 321                 public byte[] SignHash (byte[] rgbHash, string str)
 322                 {
 323                         if (rgbHash == null)
 324                                 throw new ArgumentNullException ("rgbHash");
 325                         // Fx 2.0 defaults to the SHA-1
 326                         string hashName = (str == null) ? "SHA1" : GetHashNameFromOID (str);
 327                         HashAlgorithm hash = HashAlgorithm.Create (hashName);
 328                         return PKCS1.Sign_v15 (this, hash, rgbHash);
 329                 }
 330
 331                 byte[] SignHash(byte[] rgbHash, int calgHash)
 332                 {
 333                         return PKCS1.Sign_v15 (this, InternalHashToHashAlgorithm (calgHash), rgbHash);
 334                 }
 335
 336                 static HashAlgorithm InternalHashToHashAlgorithm (int calgHash)
 337                 {
 338                         switch (calgHash) {
 339                         case Constants.CALG_MD5:
 340                                 return MD5.Create ();
 341                         case Constants.CALG_SHA1:
 342                                 return SHA1.Create ();
 343                         case Constants.CALG_SHA_256:
 344                                 return SHA256.Create ();
 345                         case Constants.CALG_SHA_384:
 346                                 return SHA384.Create ();
 347                         case Constants.CALG_SHA_512:
 348                                 return SHA512.Create ();
 349                         }
 350
 351                         throw new NotImplementedException (calgHash.ToString ());
 352                 }
 353
 354                 // NOTE: this method can work with ANY configured (OID in machine.config)
 355                 // HashAlgorithm descendant
 356                 public bool VerifyData (byte[] buffer, object halg, byte[] signature)
 357                 {
 358                         if (buffer == null)
 359                                 throw new ArgumentNullException ("buffer");
 360                         if (signature == null)
 361                                 throw new ArgumentNullException ("signature");
 362
 363                         HashAlgorithm hash = GetHash (halg);
 364                         byte[] toBeVerified = hash.ComputeHash (buffer);
 365                         return PKCS1.Verify_v15 (this, hash, toBeVerified, signature);
 366                 }
 367
 368                 public bool VerifyHash (byte[] rgbHash, string str, byte[] rgbSignature)
 369                 {
 370                         if (rgbHash == null)
 371                                 throw new ArgumentNullException ("rgbHash");
 372                         if (rgbSignature == null)
 373                                 throw new ArgumentNullException ("rgbSignature");
 374                         // Fx 2.0 defaults to the SHA-1
 375                         string hashName = (str == null) ? "SHA1" : GetHashNameFromOID (str);
 376                         HashAlgorithm hash = HashAlgorithm.Create (hashName);
 377                         return PKCS1.Verify_v15 (this, hash, rgbHash, rgbSignature);
 378                 }
 379
 380                 bool VerifyHash(byte[] rgbHash, int calgHash, byte[] rgbSignature)
 381                 {
 382                         return PKCS1.Verify_v15 (this, InternalHashToHashAlgorithm (calgHash), rgbHash, rgbSignature);
 383                 }
 384
 385                 protected override void Dispose (bool disposing)
 386                 {
 387                         if (!m_disposed) {
 388                                 // the key is persisted and we do not want it persisted
 389                                 if ((persisted) && (!persistKey)) {
 390                                         store.Remove ();        // delete the container
 391                                 }
 392                                 if (rsa != null)
 393                                         rsa.Clear ();
 394                                 // call base class
 395                                 // no need as they all are abstract before us
 396                                 m_disposed = true;
 397                         }
 398                 }
 399
 400                 // private stuff
 401
 402                 private void OnKeyGenerated (object sender, EventArgs e)
 403                 {
 404                         // the key isn't persisted and we want it persisted
 405                         if ((persistKey) && (!persisted)) {
 406                                 // save the current keypair
 407                                 store.KeyValue = this.ToXmlString (!rsa.PublicOnly);
 408                                 store.Save ();
 409                                 persisted = true;
 410                         }
 411                 }
 412                 // ICspAsymmetricAlgorithm
 413
 414                 [ComVisible (false)]
 415                 public CspKeyContainerInfo CspKeyContainerInfo {
 416                         get {
 417                                 return new CspKeyContainerInfo(store.Parameters);
 418                         }
 419                 }
 420
 421                 [ComVisible (false)]
 422                 public byte[] ExportCspBlob (bool includePrivateParameters)
 423                 {
 424                         byte[] blob = null;
 425                         if (includePrivateParameters)
 426                                 blob = CryptoConvert.ToCapiPrivateKeyBlob (this);
 427                         else
 428                                 blob = CryptoConvert.ToCapiPublicKeyBlob (this);
 429
 430                         // ALGID (bytes 4-7) - default is KEYX
 431                         // 00 24 00 00 (for CALG_RSA_SIGN)
 432                         // 00 A4 00 00 (for CALG_RSA_KEYX)
 433                         blob [5] = (byte) (((store != null) && (store.Parameters.KeyNumber == AT_SIGNATURE)) ? 0x24 : 0xA4);
 434                         return blob;
 435                 }
 436
 437                 [ComVisible (false)]
 438                 public void ImportCspBlob (byte[] keyBlob)
 439                 {
 440                         if (keyBlob == null)
 441                                 throw new ArgumentNullException ("keyBlob");
 442
 443                         RSA rsa = CryptoConvert.FromCapiKeyBlob (keyBlob);
 444                         if (rsa is RSACryptoServiceProvider) {
 445                                 // default (if no change are present in machine.config)
 446                                 RSAParameters rsap = rsa.ExportParameters (!(rsa as RSACryptoServiceProvider).PublicOnly);
 447                                 ImportParameters (rsap);
 448                         } else {
 449                                 // we can't know from RSA if the private key is available
 450                                 try {
 451                                         // so we try it...
 452                                         RSAParameters rsap = rsa.ExportParameters (true);
 453                                         ImportParameters (rsap);
 454                                 }
 455                                 catch {
 456                                         // and fall back
 457                                         RSAParameters rsap = rsa.ExportParameters (false);
 458                                         ImportParameters (rsap);
 459                                 }
 460                         }
 461
 462                         var p = new CspParameters (PROV_RSA_FULL);
 463                         p.KeyNumber = keyBlob [5] == 0x24 ? AT_SIGNATURE : AT_KEYEXCHANGE;
 464                         if (UseMachineKeyStore)
 465                                 p.Flags |= CspProviderFlags.UseMachineKeyStore;
 466                         store = new KeyPairPersistence (p);
 467                 }
 468         }
 469 }