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