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 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         public sealed class RSACryptoServiceProvider : RSA, ICspAsymmetricAlgorithm {
  41 #else
  42         public sealed class RSACryptoServiceProvider : RSA {
  43 #endif
  44                 private const int PROV_RSA_FULL = 1;    // from WinCrypt.h
  45
  46                 private KeyPairPersistence store;
  47                 private bool persistKey;
  48                 private bool persisted;
  49
  50                 private bool privateKeyExportable = true;
  51                 private bool m_disposed;
  52
  53                 private RSAManaged rsa;
  54
  55                 public RSACryptoServiceProvider ()
  56                 {
  57                         // Here it's not clear if we need to generate a keypair
  58                         // (note: MS implementation generates a keypair in this case).
  59                         // However we:
  60                         // (a) often use this constructor to import an existing keypair.
  61                         // (b) take a LOT of time to generate the RSA keypair
  62                         // So we'll generate the keypair only when (and if) it's being
  63                         // used (or exported). This should save us a lot of time (at
  64                         // least in the unit tests).
  65                         Common (1024, null);
  66                 }
  67
  68                 public RSACryptoServiceProvider (CspParameters parameters)
  69                 {
  70                         Common (1024, parameters);
  71                         // no keypair generation done at this stage
  72                 }
  73
  74                 public RSACryptoServiceProvider (int dwKeySize)
  75                 {
  76                         // Here it's clear that we need to generate a new keypair
  77                         Common (dwKeySize, null);
  78                         // no keypair generation done at this stage
  79                 }
  80
  81                 public RSACryptoServiceProvider (int dwKeySize, CspParameters parameters)
  82                 {
  83                         Common (dwKeySize, parameters);
  84                         // no keypair generation done at this stage
  85                 }
  86
  87                 private void Common (int dwKeySize, CspParameters p)
  88                 {
  89                         // Microsoft RSA CSP can do between 384 and 16384 bits keypair
  90                         LegalKeySizesValue = new KeySizes [1];
  91                         LegalKeySizesValue [0] = new KeySizes (384, 16384, 8);
  92                         base.KeySize = dwKeySize;
  93
  94                         rsa = new RSAManaged (KeySize);
  95                         rsa.KeyGenerated += new RSAManaged.KeyGeneratedEventHandler (OnKeyGenerated);
  96
  97                         persistKey = (p != null);
  98                         if (p == null) {
  99                                 p = new CspParameters (PROV_RSA_FULL);
 100 #if NET_1_1
 101                                 if (useMachineKeyStore)
 102                                         p.Flags |= CspProviderFlags.UseMachineKeyStore;
 103 #endif
 104                                 store = new KeyPairPersistence (p);
 105                                 // no need to load - it cannot exists
 106                         }
 107                         else {
 108                                 store = new KeyPairPersistence (p);
 109                                 store.Load ();
 110                                 if (store.KeyValue != null) {
 111                                         persisted = true;
 112                                         this.FromXmlString (store.KeyValue);
 113                                 }
 114                         }
 115                 }
 116
 117 #if NET_1_1
 118                 private static bool useMachineKeyStore = false;
 119
 120                 public static bool UseMachineKeyStore {
 121                         get { return useMachineKeyStore; }
 122                         set { useMachineKeyStore = value; }
 123                 }
 124 #endif
 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 #if (NET_2_0)
 155                 [ComVisible (false)]
 156                 public
 157 #else
 158                 internal
 159 #endif
 160                 bool PublicOnly {
 161                         get { return rsa.PublicOnly; }
 162                 }
 163
 164                 public override string SignatureAlgorithm {
 165                         get { return "http://www.w3.org/2000/09/xmldsig#rsa-sha1"; }
 166                 }
 167
 168                 public byte[] Decrypt (byte[] rgb, bool fOAEP)
 169                 {
 170 #if NET_1_1
 171                         if (m_disposed)
 172                                 throw new ObjectDisposedException ("rsa");
 173 #endif
 174                         // choose between OAEP or PKCS#1 v.1.5 padding
 175                         AsymmetricKeyExchangeDeformatter def = null;
 176                         if (fOAEP)
 177                                 def = new RSAOAEPKeyExchangeDeformatter (rsa);
 178                         else
 179                                 def = new RSAPKCS1KeyExchangeDeformatter (rsa);
 180
 181                         return def.DecryptKeyExchange (rgb);
 182                 }
 183
 184                 // NOTE: Unlike MS we need this method
 185                 // LAMESPEC: Not available from MS .NET framework but MS don't tell
 186                 // why! DON'T USE IT UNLESS YOU KNOW WHAT YOU ARE DOING!!! You should
 187                 // only encrypt/decrypt session (secret) key using asymmetric keys.
 188                 // Using this method to decrypt data IS dangerous (and very slow).
 189                 public override byte[] DecryptValue (byte[] rgb)
 190                 {
 191                         if (!rsa.IsCrtPossible)
 192                                 throw new CryptographicException ("Incomplete private key - missing CRT.");
 193
 194                         return rsa.DecryptValue (rgb);
 195                 }
 196
 197                 public byte[] Encrypt (byte[] rgb, bool fOAEP)
 198                 {
 199                         // choose between OAEP or PKCS#1 v.1.5 padding
 200                         AsymmetricKeyExchangeFormatter fmt = null;
 201                         if (fOAEP)
 202                                 fmt = new RSAOAEPKeyExchangeFormatter (rsa);
 203                         else
 204                                 fmt = new RSAPKCS1KeyExchangeFormatter (rsa);
 205
 206                         return fmt.CreateKeyExchange (rgb);
 207                 }
 208
 209                 // NOTE: Unlike MS we need this method
 210                 // LAMESPEC: Not available from MS .NET framework but MS don't tell
 211                 // why! DON'T USE IT UNLESS YOU KNOW WHAT YOU ARE DOING!!! You should
 212                 // only encrypt/decrypt session (secret) key using asymmetric keys.
 213                 // Using this method to encrypt data IS dangerous (and very slow).
 214                 public override byte[] EncryptValue (byte[] rgb)
 215                 {
 216                         return rsa.EncryptValue (rgb);
 217                 }
 218
 219                 public override RSAParameters ExportParameters (bool includePrivateParameters)
 220                 {
 221                         if ((includePrivateParameters) && (!privateKeyExportable))
 222                                 throw new CryptographicException ("cannot export private key");
 223
 224                         return rsa.ExportParameters (includePrivateParameters);
 225                 }
 226
 227                 public override void ImportParameters (RSAParameters parameters)
 228                 {
 229                         rsa.ImportParameters (parameters);
 230                 }
 231
 232                 private HashAlgorithm GetHash (object halg)
 233                 {
 234                         if (halg == null)
 235                                 throw new ArgumentNullException ("halg");
 236
 237                         HashAlgorithm hash = null;
 238                         if (halg is String)
 239                                 hash = HashAlgorithm.Create ((String)halg);
 240                         else if (halg is HashAlgorithm)
 241                                 hash = (HashAlgorithm) halg;
 242                         else if (halg is Type)
 243                                 hash = (HashAlgorithm) Activator.CreateInstance ((Type)halg);
 244                         else
 245                                 throw new ArgumentException ("halg");
 246
 247                         return hash;
 248                 }
 249
 250                 // NOTE: this method can work with ANY configured (OID in machine.config)
 251                 // HashAlgorithm descendant
 252                 public byte[] SignData (byte[] buffer, object halg)
 253                 {
 254 #if NET_1_1
 255                         if (buffer == null)
 256                                 throw new ArgumentNullException ("buffer");
 257 #endif
 258                         return SignData (buffer, 0, buffer.Length, halg);
 259                 }
 260
 261                 // NOTE: this method can work with ANY configured (OID in machine.config)
 262                 // HashAlgorithm descendant
 263                 public byte[] SignData (Stream inputStream, object halg)
 264                 {
 265                         HashAlgorithm hash = GetHash (halg);
 266                         byte[] toBeSigned = hash.ComputeHash (inputStream);
 267                         return PKCS1.Sign_v15 (this, hash, toBeSigned);
 268                 }
 269
 270                 // NOTE: this method can work with ANY configured (OID in machine.config)
 271                 // HashAlgorithm descendant
 272                 public byte[] SignData (byte[] buffer, int offset, int count, object halg)
 273                 {
 274                         HashAlgorithm hash = GetHash (halg);
 275                         byte[] toBeSigned = hash.ComputeHash (buffer, offset, count);
 276                         return PKCS1.Sign_v15 (this, hash, toBeSigned);
 277                 }
 278
 279                 private string GetHashNameFromOID (string oid)
 280                 {
 281                         switch (oid) {
 282                                 case "1.3.14.3.2.26":
 283                                         return "SHA1";
 284                                 case "1.2.840.113549.2.5":
 285                                         return "MD5";
 286                                 default:
 287                                         throw new NotSupportedException (oid + " is an unsupported hash algorithm for RSA signing");
 288                         }
 289                 }
 290
 291                 // LAMESPEC: str is not the hash name but an OID
 292                 // NOTE: this method is LIMITED to SHA1 and MD5 like the MS framework 1.0
 293                 // and 1.1 because there's no method to get a hash algorithm from an OID.
 294                 // However there's no such limit when using the [De]Formatter class.
 295                 public byte[] SignHash (byte[] rgbHash, string str)
 296                 {
 297                         if (rgbHash == null)
 298                                 throw new ArgumentNullException ("rgbHash");
 299 #if NET_2_0
 300                         // Fx 2.0 defaults to the SHA-1
 301                         string hashName = (str == null) ? "SHA1" : GetHashNameFromOID (str);
 302 #else
 303                         if (str == null)
 304                                 throw new CryptographicException (Locale.GetText ("No OID specified"));
 305                         string hashName = GetHashNameFromOID (str);
 306 #endif
 307                         HashAlgorithm hash = HashAlgorithm.Create (hashName);
 308                         return PKCS1.Sign_v15 (this, hash, rgbHash);
 309                 }
 310
 311                 // NOTE: this method can work with ANY configured (OID in machine.config)
 312                 // HashAlgorithm descendant
 313                 public bool VerifyData (byte[] buffer, object halg, byte[] signature)
 314                 {
 315 #if NET_1_1
 316                         if (buffer == null)
 317                                 throw new ArgumentNullException ("buffer");
 318 #endif
 319                         if (signature == null)
 320                                 throw new ArgumentNullException ("signature");
 321
 322                         HashAlgorithm hash = GetHash (halg);
 323                         byte[] toBeVerified = hash.ComputeHash (buffer);
 324                         return PKCS1.Verify_v15 (this, hash, toBeVerified, signature);
 325                 }
 326
 327                 // LAMESPEC: str is not the hash name but an OID
 328                 // NOTE: this method is LIMITED to SHA1 and MD5 like the MS framework 1.0
 329                 // and 1.1 because there's no method to get a hash algorithm from an OID.
 330                 // However there's no such limit when using the [De]Formatter class.
 331                 public bool VerifyHash (byte[] rgbHash, string str, byte[] rgbSignature)
 332                 {
 333                         if (rgbHash == null)
 334                                 throw new ArgumentNullException ("rgbHash");
 335                         if (rgbSignature == null)
 336                                 throw new ArgumentNullException ("rgbSignature");
 337 #if NET_2_0
 338                         // Fx 2.0 defaults to the SHA-1
 339                         string hashName = (str == null) ? "SHA1" : GetHashNameFromOID (str);
 340 #else
 341                         if (str == null)
 342                                 throw new CryptographicException (Locale.GetText ("No OID specified"));
 343                         string hashName = GetHashNameFromOID (str);
 344 #endif
 345                         HashAlgorithm hash = HashAlgorithm.Create (hashName);
 346                         return PKCS1.Verify_v15 (this, hash, rgbHash, rgbSignature);
 347                 }
 348
 349                 protected override void Dispose (bool disposing)
 350                 {
 351                         if (!m_disposed) {
 352                                 // the key is persisted and we do not want it persisted
 353                                 if ((persisted) && (!persistKey)) {
 354                                         store.Remove ();        // delete the container
 355                                 }
 356                                 if (rsa != null)
 357                                         rsa.Clear ();
 358                                 // call base class
 359                                 // no need as they all are abstract before us
 360                                 m_disposed = true;
 361                         }
 362                 }
 363
 364                 // private stuff
 365
 366                 private void OnKeyGenerated (object sender, EventArgs e)
 367                 {
 368                         // the key isn't persisted and we want it persisted
 369                         if ((persistKey) && (!persisted)) {
 370                                 // save the current keypair
 371                                 store.KeyValue = this.ToXmlString (!rsa.PublicOnly);
 372                                 store.Save ();
 373                                 persisted = true;
 374                         }
 375                 }
 376 #if NET_2_0
 377                 // ICspAsymmetricAlgorithm
 378
 379                 [MonoTODO ("call into KeyPairPersistence to get details")]
 380                 [ComVisible (false)]
 381                 public CspKeyContainerInfo CspKeyContainerInfo {
 382                         get { return null; }
 383                 }
 384
 385                 [MonoTODO ("call into CryptoConvert")]
 386                 [ComVisible (false)]
 387                 public byte[] ExportCspBlob (bool includePrivateParameters)
 388                 {
 389                         byte[] blob = null;
 390                         if (includePrivateParameters)
 391                                 blob = CryptoConvert.ToCapiPrivateKeyBlob (this);
 392                         else
 393                                 blob = CryptoConvert.ToCapiPublicKeyBlob (this);
 394
 395                         // ALGID (bytes 4-7) - default is KEYX
 396                         // 00 24 00 00 (for CALG_RSA_SIGN)
 397                         // 00 A4 00 00 (for CALG_RSA_KEYX)
 398                         blob [5] = 0xA4;
 399                         return blob;
 400                 }
 401
 402                 [MonoTODO ("call into CryptoConvert")]
 403                 [ComVisible (false)]
 404                 public void ImportCspBlob (byte[] rawData)
 405                 {
 406                         if (rawData == null)
 407                                 throw new ArgumentNullException ("rawData");
 408
 409                         RSA rsa = CryptoConvert.FromCapiKeyBlob (rawData);
 410                         if (rsa is RSACryptoServiceProvider) {
 411                                 // default (if no change are present in machine.config)
 412                                 RSAParameters rsap = rsa.ExportParameters (!(rsa as RSACryptoServiceProvider).PublicOnly);
 413                                 ImportParameters (rsap);
 414                         } else {
 415                                 // we can't know from RSA if the private key is available
 416                                 try {
 417                                         // so we try it...
 418                                         RSAParameters rsap = rsa.ExportParameters (true);
 419                                         ImportParameters (rsap);
 420                                 }
 421                                 catch {
 422                                         // and fall back
 423                                         RSAParameters rsap = rsa.ExportParameters (false);
 424                                         ImportParameters (rsap);
 425                                 }
 426                         }
 427                 }
 428 #endif
 429         }
 430 }