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 #if NET_2_0
  40         [ComVisible (true)]
  41         public sealed class RSACryptoServiceProvider : RSA, ICspAsymmetricAlgorithm {
  42 #else
  43         public sealed class RSACryptoServiceProvider : RSA {
  44 #endif
  45                 private const int PROV_RSA_FULL = 1;    // from WinCrypt.h
  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 NET_1_1
 102                                 if (useMachineKeyStore)
 103                                         p.Flags |= CspProviderFlags.UseMachineKeyStore;
 104 #endif
 105                                 store = new KeyPairPersistence (p);
 106                                 // no need to load - it cannot exists
 107                         }
 108                         else {
 109                                 store = new KeyPairPersistence (p);
 110                                 store.Load ();
 111                                 if (store.KeyValue != null) {
 112                                         persisted = true;
 113                                         this.FromXmlString (store.KeyValue);
 114                                 }
 115                         }
 116                 }
 117
 118 #if NET_1_1
 119                 private static bool useMachineKeyStore = false;
 120
 121                 public static bool UseMachineKeyStore {
 122                         get { return useMachineKeyStore; }
 123                         set { useMachineKeyStore = value; }
 124                 }
 125 #endif
 126
 127                 ~RSACryptoServiceProvider ()
 128                 {
 129                         // Zeroize private key
 130                         Dispose (false);
 131                 }
 132
 133                 public override string KeyExchangeAlgorithm {
 134                         get { return "RSA-PKCS1-KeyEx"; }
 135                 }
 136
 137                 public override int KeySize {
 138                         get {
 139                                 if (rsa == null)
 140                                       return KeySizeValue;
 141                                 else
 142                                       return rsa.KeySize;
 143                         }
 144                 }
 145
 146                 public bool PersistKeyInCsp {
 147                         get { return persistKey; }
 148                         set {
 149                                 persistKey = value;
 150                                 if (persistKey)
 151                                         OnKeyGenerated (rsa, null);
 152                         }
 153                 }
 154
 155 #if (NET_2_0)
 156                 [ComVisible (false)]
 157                 public
 158 #else
 159                 internal
 160 #endif
 161                 bool PublicOnly {
 162                         get { return rsa.PublicOnly; }
 163                 }
 164
 165                 public override string SignatureAlgorithm {
 166                         get { return "http://www.w3.org/2000/09/xmldsig#rsa-sha1"; }
 167                 }
 168
 169                 public byte[] Decrypt (byte[] rgb, bool fOAEP)
 170                 {
 171 #if NET_1_1
 172                         if (m_disposed)
 173                                 throw new ObjectDisposedException ("rsa");
 174 #endif
 175                         // choose between OAEP or PKCS#1 v.1.5 padding
 176                         AsymmetricKeyExchangeDeformatter def = null;
 177                         if (fOAEP)
 178                                 def = new RSAOAEPKeyExchangeDeformatter (rsa);
 179                         else
 180                                 def = new RSAPKCS1KeyExchangeDeformatter (rsa);
 181
 182                         return def.DecryptKeyExchange (rgb);
 183                 }
 184
 185                 // NOTE: Unlike MS we need this method
 186                 // LAMESPEC: Not available from MS .NET framework but MS don't tell
 187                 // why! DON'T USE IT UNLESS YOU KNOW WHAT YOU ARE DOING!!! You should
 188                 // only encrypt/decrypt session (secret) key using asymmetric keys.
 189                 // Using this method to decrypt data IS dangerous (and very slow).
 190                 public override byte[] DecryptValue (byte[] rgb)
 191                 {
 192                         if (!rsa.IsCrtPossible)
 193                                 throw new CryptographicException ("Incomplete private key - missing CRT.");
 194
 195                         return rsa.DecryptValue (rgb);
 196                 }
 197
 198                 public byte[] Encrypt (byte[] rgb, bool fOAEP)
 199                 {
 200                         // choose between OAEP or PKCS#1 v.1.5 padding
 201                         AsymmetricKeyExchangeFormatter fmt = null;
 202                         if (fOAEP)
 203                                 fmt = new RSAOAEPKeyExchangeFormatter (rsa);
 204                         else
 205                                 fmt = new RSAPKCS1KeyExchangeFormatter (rsa);
 206
 207                         return fmt.CreateKeyExchange (rgb);
 208                 }
 209
 210                 // NOTE: Unlike MS we need this method
 211                 // LAMESPEC: Not available from MS .NET framework but MS don't tell
 212                 // why! DON'T USE IT UNLESS YOU KNOW WHAT YOU ARE DOING!!! You should
 213                 // only encrypt/decrypt session (secret) key using asymmetric keys.
 214                 // Using this method to encrypt data IS dangerous (and very slow).
 215                 public override byte[] EncryptValue (byte[] rgb)
 216                 {
 217                         return rsa.EncryptValue (rgb);
 218                 }
 219
 220                 public override RSAParameters ExportParameters (bool includePrivateParameters)
 221                 {
 222                         if ((includePrivateParameters) && (!privateKeyExportable))
 223                                 throw new CryptographicException ("cannot export private key");
 224
 225                         return rsa.ExportParameters (includePrivateParameters);
 226                 }
 227
 228                 public override void ImportParameters (RSAParameters parameters)
 229                 {
 230                         rsa.ImportParameters (parameters);
 231                 }
 232
 233                 private HashAlgorithm GetHash (object halg)
 234                 {
 235                         if (halg == null)
 236                                 throw new ArgumentNullException ("halg");
 237
 238                         HashAlgorithm hash = null;
 239                         if (halg is String)
 240                                 hash = HashAlgorithm.Create ((String)halg);
 241                         else if (halg is HashAlgorithm)
 242                                 hash = (HashAlgorithm) halg;
 243                         else if (halg is Type)
 244                                 hash = (HashAlgorithm) Activator.CreateInstance ((Type)halg);
 245                         else
 246                                 throw new ArgumentException ("halg");
 247
 248                         return hash;
 249                 }
 250
 251                 // NOTE: this method can work with ANY configured (OID in machine.config)
 252                 // HashAlgorithm descendant
 253                 public byte[] SignData (byte[] buffer, object halg)
 254                 {
 255 #if NET_1_1
 256                         if (buffer == null)
 257                                 throw new ArgumentNullException ("buffer");
 258 #endif
 259                         return SignData (buffer, 0, buffer.Length, halg);
 260                 }
 261
 262                 // NOTE: this method can work with ANY configured (OID in machine.config)
 263                 // HashAlgorithm descendant
 264                 public byte[] SignData (Stream inputStream, object halg)
 265                 {
 266                         HashAlgorithm hash = GetHash (halg);
 267                         byte[] toBeSigned = hash.ComputeHash (inputStream);
 268                         return PKCS1.Sign_v15 (this, hash, toBeSigned);
 269                 }
 270
 271                 // NOTE: this method can work with ANY configured (OID in machine.config)
 272                 // HashAlgorithm descendant
 273                 public byte[] SignData (byte[] buffer, int offset, int count, object halg)
 274                 {
 275                         HashAlgorithm hash = GetHash (halg);
 276                         byte[] toBeSigned = hash.ComputeHash (buffer, offset, count);
 277                         return PKCS1.Sign_v15 (this, hash, toBeSigned);
 278                 }
 279
 280                 private string GetHashNameFromOID (string oid)
 281                 {
 282                         switch (oid) {
 283                                 case "1.3.14.3.2.26":
 284                                         return "SHA1";
 285                                 case "1.2.840.113549.2.5":
 286                                         return "MD5";
 287                                 default:
 288                                         throw new NotSupportedException (oid + " is an unsupported hash algorithm for RSA signing");
 289                         }
 290                 }
 291
 292                 // LAMESPEC: str is not the hash name but an OID
 293                 // NOTE: this method is LIMITED to SHA1 and MD5 like the MS framework 1.0
 294                 // and 1.1 because there's no method to get a hash algorithm from an OID.
 295                 // However there's no such limit when using the [De]Formatter class.
 296                 public byte[] SignHash (byte[] rgbHash, string str)
 297                 {
 298                         if (rgbHash == null)
 299                                 throw new ArgumentNullException ("rgbHash");
 300 #if NET_2_0
 301                         // Fx 2.0 defaults to the SHA-1
 302                         string hashName = (str == null) ? "SHA1" : GetHashNameFromOID (str);
 303 #else
 304                         if (str == null)
 305                                 throw new CryptographicException (Locale.GetText ("No OID specified"));
 306                         string hashName = GetHashNameFromOID (str);
 307 #endif
 308                         HashAlgorithm hash = HashAlgorithm.Create (hashName);
 309                         return PKCS1.Sign_v15 (this, hash, rgbHash);
 310                 }
 311
 312                 // NOTE: this method can work with ANY configured (OID in machine.config)
 313                 // HashAlgorithm descendant
 314                 public bool VerifyData (byte[] buffer, object halg, byte[] signature)
 315                 {
 316 #if NET_1_1
 317                         if (buffer == null)
 318                                 throw new ArgumentNullException ("buffer");
 319 #endif
 320                         if (signature == null)
 321                                 throw new ArgumentNullException ("signature");
 322
 323                         HashAlgorithm hash = GetHash (halg);
 324                         byte[] toBeVerified = hash.ComputeHash (buffer);
 325                         return PKCS1.Verify_v15 (this, hash, toBeVerified, signature);
 326                 }
 327
 328                 // LAMESPEC: str is not the hash name but an OID
 329                 // NOTE: this method is LIMITED to SHA1 and MD5 like the MS framework 1.0
 330                 // and 1.1 because there's no method to get a hash algorithm from an OID.
 331                 // However there's no such limit when using the [De]Formatter class.
 332                 public bool VerifyHash (byte[] rgbHash, string str, byte[] rgbSignature)
 333                 {
 334                         if (rgbHash == null)
 335                                 throw new ArgumentNullException ("rgbHash");
 336                         if (rgbSignature == null)
 337                                 throw new ArgumentNullException ("rgbSignature");
 338 #if NET_2_0
 339                         // Fx 2.0 defaults to the SHA-1
 340                         string hashName = (str == null) ? "SHA1" : GetHashNameFromOID (str);
 341 #else
 342                         if (str == null)
 343                                 throw new CryptographicException (Locale.GetText ("No OID specified"));
 344                         string hashName = GetHashNameFromOID (str);
 345 #endif
 346                         HashAlgorithm hash = HashAlgorithm.Create (hashName);
 347                         return PKCS1.Verify_v15 (this, hash, rgbHash, rgbSignature);
 348                 }
 349
 350                 protected override void Dispose (bool disposing)
 351                 {
 352                         if (!m_disposed) {
 353                                 // the key is persisted and we do not want it persisted
 354                                 if ((persisted) && (!persistKey)) {
 355                                         store.Remove ();        // delete the container
 356                                 }
 357                                 if (rsa != null)
 358                                         rsa.Clear ();
 359                                 // call base class
 360                                 // no need as they all are abstract before us
 361                                 m_disposed = true;
 362                         }
 363                 }
 364
 365                 // private stuff
 366
 367                 private void OnKeyGenerated (object sender, EventArgs e)
 368                 {
 369                         // the key isn't persisted and we want it persisted
 370                         if ((persistKey) && (!persisted)) {
 371                                 // save the current keypair
 372                                 store.KeyValue = this.ToXmlString (!rsa.PublicOnly);
 373                                 store.Save ();
 374                                 persisted = true;
 375                         }
 376                 }
 377 #if NET_2_0
 378                 // ICspAsymmetricAlgorithm
 379
 380                 [MonoTODO ("call into KeyPairPersistence to get details")]
 381                 [ComVisible (false)]
 382                 public CspKeyContainerInfo CspKeyContainerInfo {
 383                         get { return null; }
 384                 }
 385
 386                 [MonoTODO ("call into CryptoConvert")]
 387                 [ComVisible (false)]
 388                 public byte[] ExportCspBlob (bool includePrivateParameters)
 389                 {
 390                         byte[] blob = null;
 391                         if (includePrivateParameters)
 392                                 blob = CryptoConvert.ToCapiPrivateKeyBlob (this);
 393                         else
 394                                 blob = CryptoConvert.ToCapiPublicKeyBlob (this);
 395
 396                         // ALGID (bytes 4-7) - default is KEYX
 397                         // 00 24 00 00 (for CALG_RSA_SIGN)
 398                         // 00 A4 00 00 (for CALG_RSA_KEYX)
 399                         blob [5] = 0xA4;
 400                         return blob;
 401                 }
 402
 403                 [MonoTODO ("call into CryptoConvert")]
 404                 [ComVisible (false)]
 405                 public void ImportCspBlob (byte[] rawData)
 406                 {
 407                         if (rawData == null)
 408                                 throw new ArgumentNullException ("rawData");
 409
 410                         RSA rsa = CryptoConvert.FromCapiKeyBlob (rawData);
 411                         if (rsa is RSACryptoServiceProvider) {
 412                                 // default (if no change are present in machine.config)
 413                                 RSAParameters rsap = rsa.ExportParameters (!(rsa as RSACryptoServiceProvider).PublicOnly);
 414                                 ImportParameters (rsap);
 415                         } else {
 416                                 // we can't know from RSA if the private key is available
 417                                 try {
 418                                         // so we try it...
 419                                         RSAParameters rsap = rsa.ExportParameters (true);
 420                                         ImportParameters (rsap);
 421                                 }
 422                                 catch {
 423                                         // and fall back
 424                                         RSAParameters rsap = rsa.ExportParameters (false);
 425                                         ImportParameters (rsap);
 426                                 }
 427                         }
 428                 }
 429 #endif
 430         }
 431 }