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         [ComVisible (true)]
  40         public sealed class RSACryptoServiceProvider : RSA, ICspAsymmetricAlgorithm {
  41                 private const int PROV_RSA_FULL = 1;    // from WinCrypt.h
  42                 private const int AT_KEYEXCHANGE = 1;
  43                 private const int AT_SIGNATURE = 2;
  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                         : this (1024)
  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                 }
  66
  67                 public RSACryptoServiceProvider (CspParameters parameters)
  68                         : this (1024, parameters)
  69                 {
  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, false);
  77                         // no keypair generation done at this stage
  78                 }
  79
  80                 public RSACryptoServiceProvider (int dwKeySize, CspParameters parameters)
  81                 {
  82                         bool has_parameters = parameters != null;
  83                         Common (dwKeySize, has_parameters);
  84                         if (has_parameters)
  85                                 Common (parameters);
  86                         // no keypair generation done at this stage
  87                 }
  88
  89                 void Common (int dwKeySize, bool parameters)
  90                 {
  91                         // Microsoft RSA CSP can do between 384 and 16384 bits keypair
  92                         LegalKeySizesValue = new KeySizes [1];
  93                         LegalKeySizesValue [0] = new KeySizes (384, 16384, 8);
  94                         base.KeySize = dwKeySize;
  95
  96                         rsa = new RSAManaged (KeySize);
  97                         rsa.KeyGenerated += new RSAManaged.KeyGeneratedEventHandler (OnKeyGenerated);
  98
  99                         persistKey = parameters;
 100                         if (parameters)
 101                                 return;
 102
 103                         // no need to load - it cannot exists
 104                         var p = new CspParameters (PROV_RSA_FULL);
 105                         if (useMachineKeyStore)
 106                                 p.Flags |= CspProviderFlags.UseMachineKeyStore;
 107                         store = new KeyPairPersistence (p);
 108                 }
 109
 110                 void Common (CspParameters p)
 111                 {
 112                         store = new KeyPairPersistence (p);
 113                         bool exists = store.Load ();
 114                         bool required = (p.Flags & CspProviderFlags.UseExistingKey) != 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                 private static bool useMachineKeyStore;
 126
 127                 public static bool UseMachineKeyStore {
 128                         get { return useMachineKeyStore; }
 129                         set { useMachineKeyStore = value; }
 130                 }
 131
 132                 ~RSACryptoServiceProvider ()
 133                 {
 134                         // Zeroize private key
 135                         Dispose (false);
 136                 }
 137
 138                 public override string KeyExchangeAlgorithm {
 139                         get { return "RSA-PKCS1-KeyEx"; }
 140                 }
 141
 142                 public override int KeySize {
 143                         get {
 144                                 if (rsa == null)
 145                                       return KeySizeValue;
 146                                 else
 147                                       return rsa.KeySize;
 148                         }
 149                 }
 150
 151                 public bool PersistKeyInCsp {
 152                         get { return persistKey; }
 153                         set {
 154                                 persistKey = value;
 155                                 if (persistKey)
 156                                         OnKeyGenerated (rsa, null);
 157                         }
 158                 }
 159
 160                 [ComVisible (false)]
 161                 public 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 (rgb == null)
 172                                 throw new ArgumentNullException("rgb");
 173
 174                         // size check -- must be at most the modulus size
 175                         if (rgb.Length > (KeySize / 8))
 176                                 throw new CryptographicException(Environment.GetResourceString("Cryptography_Padding_DecDataTooBig", KeySize / 8));
 177
 178                         if (m_disposed)
 179                                 throw new ObjectDisposedException ("rsa");
 180                         // choose between OAEP or PKCS#1 v.1.5 padding
 181                         AsymmetricKeyExchangeDeformatter def = null;
 182                         if (fOAEP)
 183                                 def = new RSAOAEPKeyExchangeDeformatter (rsa);
 184                         else
 185                                 def = new RSAPKCS1KeyExchangeDeformatter (rsa);
 186
 187                         return def.DecryptKeyExchange (rgb);
 188                 }
 189
 190                 // NOTE: Unlike MS we need this method
 191                 // LAMESPEC: Not available from MS .NET framework but MS don't tell
 192                 // why! DON'T USE IT UNLESS YOU KNOW WHAT YOU ARE DOING!!! You should
 193                 // only encrypt/decrypt session (secret) key using asymmetric keys.
 194                 // Using this method to decrypt data IS dangerous (and very slow).
 195                 public override byte[] DecryptValue (byte[] rgb)
 196                 {
 197                         if (!rsa.IsCrtPossible)
 198                                 throw new CryptographicException ("Incomplete private key - missing CRT.");
 199
 200                         return rsa.DecryptValue (rgb);
 201                 }
 202
 203                 public byte[] Encrypt (byte[] rgb, bool fOAEP)
 204                 {
 205                         // choose between OAEP or PKCS#1 v.1.5 padding
 206                         AsymmetricKeyExchangeFormatter fmt = null;
 207                         if (fOAEP)
 208                                 fmt = new RSAOAEPKeyExchangeFormatter (rsa);
 209                         else
 210                                 fmt = new RSAPKCS1KeyExchangeFormatter (rsa);
 211
 212                         return fmt.CreateKeyExchange (rgb);
 213                 }
 214
 215                 // NOTE: Unlike MS we need this method
 216                 // LAMESPEC: Not available from MS .NET framework but MS don't tell
 217                 // why! DON'T USE IT UNLESS YOU KNOW WHAT YOU ARE DOING!!! You should
 218                 // only encrypt/decrypt session (secret) key using asymmetric keys.
 219                 // Using this method to encrypt data IS dangerous (and very slow).
 220                 public override byte[] EncryptValue (byte[] rgb)
 221                 {
 222                         return rsa.EncryptValue (rgb);
 223                 }
 224
 225                 public override RSAParameters ExportParameters (bool includePrivateParameters)
 226                 {
 227                         if ((includePrivateParameters) && (!privateKeyExportable))
 228                                 throw new CryptographicException ("cannot export private key");
 229
 230                         var rsaParams = rsa.ExportParameters (includePrivateParameters);
 231                         if (includePrivateParameters) {
 232                                 // we want an ArgumentNullException is only the D is missing, but a
 233                                 // CryptographicException if other parameters (CRT) are missings
 234                                 if (rsaParams.D == null) {
 235                                         throw new ArgumentNullException ("Missing D parameter for the private key.");
 236                                 } else if ((rsaParams.P == null) || (rsaParams.Q == null) || (rsaParams.DP == null) ||
 237                                         (rsaParams.DQ == null) || (rsaParams.InverseQ == null)) {
 238                                         // note: we can import a private key, using FromXmlString,
 239                                         // without the CRT parameters but we export it using ToXmlString!
 240                                         throw new CryptographicException ("Missing some CRT parameters for the private key.");
 241                                 }
 242                         }
 243
 244                         return rsaParams;
 245                 }
 246
 247                 public override void ImportParameters (RSAParameters parameters)
 248                 {
 249                         rsa.ImportParameters (parameters);
 250                 }
 251
 252                 private HashAlgorithm GetHash (object halg)
 253                 {
 254                         if (halg == null)
 255                                 throw new ArgumentNullException ("halg");
 256
 257                         HashAlgorithm hash = null;
 258                         if (halg is String)
 259                                 hash = GetHashFromString ((string) halg);
 260                         else if (halg is HashAlgorithm)
 261                                 hash = (HashAlgorithm) halg;
 262                         else if (halg is Type)
 263                                 hash = (HashAlgorithm) Activator.CreateInstance ((Type)halg);
 264                         else
 265                                 throw new ArgumentException ("halg");
 266
 267                         if (hash == null)
 268                                 throw new ArgumentException (
 269                                                 "Could not find provider for halg='" + halg + "'.",
 270                                                 "halg");
 271
 272                         return hash;
 273                 }
 274
 275                 private HashAlgorithm GetHashFromString (string name)
 276                 {
 277                         HashAlgorithm hash = HashAlgorithm.Create (name);
 278                         if (hash != null)
 279                                 return hash;
 280                         try {
 281                                 return HashAlgorithm.Create (GetHashNameFromOID (name));
 282                         } catch (CryptographicException e) {
 283                                 throw new ArgumentException (e.Message, "halg", e);
 284                         }
 285                 }
 286
 287                 // NOTE: this method can work with ANY configured (OID in machine.config)
 288                 // HashAlgorithm descendant
 289                 public byte[] SignData (byte[] buffer, object halg)
 290                 {
 291                         if (buffer == null)
 292                                 throw new ArgumentNullException ("buffer");
 293                         return SignData (buffer, 0, buffer.Length, halg);
 294                 }
 295
 296                 // NOTE: this method can work with ANY configured (OID in machine.config)
 297                 // HashAlgorithm descendant
 298                 public byte[] SignData (Stream inputStream, object halg)
 299                 {
 300                         HashAlgorithm hash = GetHash (halg);
 301                         byte[] toBeSigned = hash.ComputeHash (inputStream);
 302                         return PKCS1.Sign_v15 (this, hash, toBeSigned);
 303                 }
 304
 305                 // NOTE: this method can work with ANY configured (OID in machine.config)
 306                 // HashAlgorithm descendant
 307                 public byte[] SignData (byte[] buffer, int offset, int count, object halg)
 308                 {
 309                         HashAlgorithm hash = GetHash (halg);
 310                         byte[] toBeSigned = hash.ComputeHash (buffer, offset, count);
 311                         return PKCS1.Sign_v15 (this, hash, toBeSigned);
 312                 }
 313
 314                 private string GetHashNameFromOID (string oid)
 315                 {
 316                         switch (oid) {
 317                         case "1.3.14.3.2.26":
 318                                 return "SHA1";
 319                         case "1.2.840.113549.2.5":
 320                                 return "MD5";
 321                         case "2.16.840.1.101.3.4.2.1":
 322                                 return "SHA256";
 323                         case "2.16.840.1.101.3.4.2.2":
 324                                 return "SHA384";
 325                         case "2.16.840.1.101.3.4.2.3":
 326                                 return "SHA512";
 327                         default:
 328                                 throw new CryptographicException (oid + " is an unsupported hash algorithm for RSA signing");
 329                         }
 330                 }
 331
 332                 public byte[] SignHash (byte[] rgbHash, string str)
 333                 {
 334                         if (rgbHash == null)
 335                                 throw new ArgumentNullException ("rgbHash");
 336                         // Fx 2.0 defaults to the SHA-1
 337                         string hashName = (str == null) ? "SHA1" : GetHashNameFromOID (str);
 338                         HashAlgorithm hash = HashAlgorithm.Create (hashName);
 339                         return PKCS1.Sign_v15 (this, hash, rgbHash);
 340                 }
 341
 342                 // NOTE: this method can work with ANY configured (OID in machine.config)
 343                 // HashAlgorithm descendant
 344                 public bool VerifyData (byte[] buffer, object halg, byte[] signature)
 345                 {
 346                         if (buffer == null)
 347                                 throw new ArgumentNullException ("buffer");
 348                         if (signature == null)
 349                                 throw new ArgumentNullException ("signature");
 350
 351                         HashAlgorithm hash = GetHash (halg);
 352                         byte[] toBeVerified = hash.ComputeHash (buffer);
 353                         return PKCS1.Verify_v15 (this, hash, toBeVerified, signature);
 354                 }
 355
 356                 public bool VerifyHash (byte[] rgbHash, string str, byte[] rgbSignature)
 357                 {
 358                         if (rgbHash == null)
 359                                 throw new ArgumentNullException ("rgbHash");
 360                         if (rgbSignature == null)
 361                                 throw new ArgumentNullException ("rgbSignature");
 362                         // Fx 2.0 defaults to the SHA-1
 363                         string hashName = (str == null) ? "SHA1" : GetHashNameFromOID (str);
 364                         HashAlgorithm hash = HashAlgorithm.Create (hashName);
 365                         return PKCS1.Verify_v15 (this, hash, rgbHash, rgbSignature);
 366                 }
 367
 368                 protected override void Dispose (bool disposing)
 369                 {
 370                         if (!m_disposed) {
 371                                 // the key is persisted and we do not want it persisted
 372                                 if ((persisted) && (!persistKey)) {
 373                                         store.Remove ();        // delete the container
 374                                 }
 375                                 if (rsa != null)
 376                                         rsa.Clear ();
 377                                 // call base class
 378                                 // no need as they all are abstract before us
 379                                 m_disposed = true;
 380                         }
 381                 }
 382
 383                 // private stuff
 384
 385                 private void OnKeyGenerated (object sender, EventArgs e)
 386                 {
 387                         // the key isn't persisted and we want it persisted
 388                         if ((persistKey) && (!persisted)) {
 389                                 // save the current keypair
 390                                 store.KeyValue = this.ToXmlString (!rsa.PublicOnly);
 391                                 store.Save ();
 392                                 persisted = true;
 393                         }
 394                 }
 395                 // ICspAsymmetricAlgorithm
 396
 397                 [ComVisible (false)]
 398                 public CspKeyContainerInfo CspKeyContainerInfo {
 399                         get {
 400                                 return new CspKeyContainerInfo(store.Parameters);
 401                         }
 402                 }
 403
 404                 [ComVisible (false)]
 405                 public byte[] ExportCspBlob (bool includePrivateParameters)
 406                 {
 407                         byte[] blob = null;
 408                         if (includePrivateParameters)
 409                                 blob = CryptoConvert.ToCapiPrivateKeyBlob (this);
 410                         else
 411                                 blob = CryptoConvert.ToCapiPublicKeyBlob (this);
 412
 413                         // ALGID (bytes 4-7) - default is KEYX
 414                         // 00 24 00 00 (for CALG_RSA_SIGN)
 415                         // 00 A4 00 00 (for CALG_RSA_KEYX)
 416                         blob [5] = (byte) (((store != null) && (store.Parameters.KeyNumber == AT_SIGNATURE)) ? 0x24 : 0xA4);
 417                         return blob;
 418                 }
 419
 420                 [ComVisible (false)]
 421                 public void ImportCspBlob (byte[] keyBlob)
 422                 {
 423                         if (keyBlob == null)
 424                                 throw new ArgumentNullException ("keyBlob");
 425
 426                         RSA rsa = CryptoConvert.FromCapiKeyBlob (keyBlob);
 427                         if (rsa is RSACryptoServiceProvider) {
 428                                 // default (if no change are present in machine.config)
 429                                 RSAParameters rsap = rsa.ExportParameters (!(rsa as RSACryptoServiceProvider).PublicOnly);
 430                                 ImportParameters (rsap);
 431                         } else {
 432                                 // we can't know from RSA if the private key is available
 433                                 try {
 434                                         // so we try it...
 435                                         RSAParameters rsap = rsa.ExportParameters (true);
 436                                         ImportParameters (rsap);
 437                                 }
 438                                 catch {
 439                                         // and fall back
 440                                         RSAParameters rsap = rsa.ExportParameters (false);
 441                                         ImportParameters (rsap);
 442                                 }
 443                         }
 444
 445                         var p = new CspParameters (PROV_RSA_FULL);
 446                         p.KeyNumber = keyBlob [5] == 0x24 ? AT_SIGNATURE : AT_KEYEXCHANGE;
 447                         if (useMachineKeyStore)
 448                                 p.Flags |= CspProviderFlags.UseMachineKeyStore;
 449                         store = new KeyPairPersistence (p);
 450                 }
 451         }
 452 }