mcs/class/System/System.Security.Cryptography.X509Certificates/X509Certificate2.cs

   1 //
   2 // System.Security.Cryptography.X509Certificate2 class
   3 //
   4 // Author:
   5 //      Sebastien Pouliot  <sebastien@ximian.com>
   6 //
   7 // (C) 2003 Motus Technologies Inc. (http://www.motus.com)
   8 // Copyright (C) 2004-2006 Novell Inc. (http://www.novell.com)
   9 //
  10 // Permission is hereby granted, free of charge, to any person obtaining
  11 // a copy of this software and associated documentation files (the
  12 // "Software"), to deal in the Software without restriction, including
  13 // without limitation the rights to use, copy, modify, merge, publish,
  14 // distribute, sublicense, and/or sell copies of the Software, and to
  15 // permit persons to whom the Software is furnished to do so, subject to
  16 // the following conditions:
  17 //
  18 // The above copyright notice and this permission notice shall be
  19 // included in all copies or substantial portions of the Software.
  20 //
  21 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  22 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  23 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  24 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  25 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  26 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  27 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  28 //
  29
  30 #if SECURITY_DEP
  31
  32 #if MONOTOUCH
  33 using Mono.Security;
  34 using Mono.Security.Cryptography;
  35 using MX = Mono.Security.X509;
  36 #else
  37 extern alias MonoSecurity;
  38
  39 using MonoSecurity::Mono.Security;
  40 using MonoSecurity::Mono.Security.Cryptography;
  41 using MX = MonoSecurity::Mono.Security.X509;
  42 #endif
  43
  44 #endif
  45
  46 using System.IO;
  47 using System.Text;
  48
  49 namespace System.Security.Cryptography.X509Certificates {
  50
  51 #if NET_4_0
  52         [Serializable]
  53 #endif
  54         public class X509Certificate2 : X509Certificate {
  55 #if !SECURITY_DEP
  56                 // Used in Mono.Security HttpsClientStream
  57                 public X509Certificate2 (byte[] rawData)
  58                 {
  59                 }
  60 #endif
  61 #if SECURITY_DEP
  62                 private bool _archived;
  63                 private X509ExtensionCollection _extensions;
  64                 private string _name = String.Empty;
  65                 private string _serial;
  66                 private PublicKey _publicKey;
  67                 private X500DistinguishedName issuer_name;
  68                 private X500DistinguishedName subject_name;
  69                 private Oid signature_algorithm;
  70
  71                 private MX.X509Certificate _cert;
  72
  73                 private static string empty_error = Locale.GetText ("Certificate instance is empty.");
  74
  75                 // constructors
  76
  77                 public X509Certificate2 ()
  78                 {
  79                         _cert = null;
  80                 }
  81
  82                 public X509Certificate2 (byte[] rawData)
  83                 {
  84                         Import (rawData, (string)null, X509KeyStorageFlags.DefaultKeySet);
  85                 }
  86
  87                 public X509Certificate2 (byte[] rawData, string password)
  88                 {
  89                         Import (rawData, password, X509KeyStorageFlags.DefaultKeySet);
  90                 }
  91
  92                 public X509Certificate2 (byte[] rawData, SecureString password)
  93                 {
  94                         Import (rawData, password, X509KeyStorageFlags.DefaultKeySet);
  95                 }
  96
  97                 public X509Certificate2 (byte[] rawData, string password, X509KeyStorageFlags keyStorageFlags)
  98                 {
  99                         Import (rawData, password, keyStorageFlags);
 100                 }
 101
 102                 public X509Certificate2 (byte[] rawData, SecureString password, X509KeyStorageFlags keyStorageFlags)
 103                 {
 104                         Import (rawData, password, keyStorageFlags);
 105                 }
 106
 107                 public X509Certificate2 (string fileName)
 108                 {
 109                         Import (fileName, String.Empty, X509KeyStorageFlags.DefaultKeySet);
 110                 }
 111
 112                 public X509Certificate2 (string fileName, string password)
 113                 {
 114                         Import (fileName, password, X509KeyStorageFlags.DefaultKeySet);
 115                 }
 116
 117                 public X509Certificate2 (string fileName, SecureString password)
 118                 {
 119                         Import (fileName, password, X509KeyStorageFlags.DefaultKeySet);
 120                 }
 121
 122                 public X509Certificate2 (string fileName, string password, X509KeyStorageFlags keyStorageFlags)
 123                 {
 124                         Import (fileName, password, keyStorageFlags);
 125                 }
 126
 127                 public X509Certificate2 (string fileName, SecureString password, X509KeyStorageFlags keyStorageFlags)
 128                 {
 129                         Import (fileName, password, keyStorageFlags);
 130                 }
 131
 132                 public X509Certificate2 (IntPtr handle) : base (handle)
 133                 {
 134                         _cert = new MX.X509Certificate (base.GetRawCertData ());
 135                 }
 136
 137                 public X509Certificate2 (X509Certificate certificate)
 138                         : base (certificate)
 139                 {
 140                         _cert = new MX.X509Certificate (base.GetRawCertData ());
 141                 }
 142
 143                 // properties
 144
 145                 public bool Archived {
 146                         get {
 147                                 if (_cert == null)
 148                                         throw new CryptographicException (empty_error);
 149                                 return _archived;
 150                         }
 151                         set {
 152                                 if (_cert == null)
 153                                         throw new CryptographicException (empty_error);
 154                                 _archived = value;
 155                         }
 156                 }
 157
 158                 public X509ExtensionCollection Extensions {
 159                         get {
 160                                 if (_cert == null)
 161                                         throw new CryptographicException (empty_error);
 162                                 if (_extensions == null)
 163                                         _extensions = new X509ExtensionCollection (_cert);
 164                                 return _extensions;
 165                         }
 166                 }
 167
 168                 public string FriendlyName {
 169                         get {
 170                                 if (_cert == null)
 171                                         throw new CryptographicException (empty_error);
 172                                 return _name;
 173                         }
 174                         set {
 175                                 if (_cert == null)
 176                                         throw new CryptographicException (empty_error);
 177                                 _name = value;
 178                         }
 179                 }
 180
 181                 // FIXME - Could be more efficient
 182                 public bool HasPrivateKey {
 183                         get { return PrivateKey != null; }
 184                 }
 185
 186                 public X500DistinguishedName IssuerName {
 187                         get {
 188                                 if (_cert == null)
 189                                         throw new CryptographicException (empty_error);
 190                                 if (issuer_name == null)
 191                                         issuer_name = new X500DistinguishedName (_cert.GetIssuerName ().GetBytes ());
 192                                 return issuer_name;
 193                         }
 194                 }
 195
 196                 public DateTime NotAfter {
 197                         get {
 198                                 if (_cert == null)
 199                                         throw new CryptographicException (empty_error);
 200                                 return _cert.ValidUntil.ToLocalTime ();
 201                         }
 202                 }
 203
 204                 public DateTime NotBefore {
 205                         get {
 206                                 if (_cert == null)
 207                                         throw new CryptographicException (empty_error);
 208                                 return _cert.ValidFrom.ToLocalTime ();
 209                         }
 210                 }
 211
 212                 public AsymmetricAlgorithm PrivateKey {
 213                         get {
 214                                 if (_cert == null)
 215                                         throw new CryptographicException (empty_error);
 216                                 try {
 217                                         if (_cert.RSA != null) {
 218                                                 RSACryptoServiceProvider rcsp = _cert.RSA as RSACryptoServiceProvider;
 219                                                 if (rcsp != null)
 220                                                         return rcsp.PublicOnly ? null : rcsp;
 221
 222                                                 RSAManaged rsam = _cert.RSA as RSAManaged;
 223                                                 if (rsam != null)
 224                                                         return rsam.PublicOnly ? null : rsam;
 225
 226                                                 _cert.RSA.ExportParameters (true);
 227                                                 return _cert.RSA;
 228                                         } else if (_cert.DSA != null) {
 229                                                 DSACryptoServiceProvider dcsp = _cert.DSA as DSACryptoServiceProvider;
 230                                                 if (dcsp != null)
 231                                                         return dcsp.PublicOnly ? null : dcsp;
 232
 233                                                 _cert.DSA.ExportParameters (true);
 234                                                 return _cert.DSA;
 235                                         }
 236                                 }
 237                                 catch {
 238                                 }
 239                                 return null;
 240                         }
 241                         set {
 242                                 if (_cert == null)
 243                                         throw new CryptographicException (empty_error);
 244
 245                                 // allow NULL so we can "forget" the key associated to the certificate
 246                                 // e.g. in case we want to export it in another format (see bug #396620)
 247                                 if (value == null) {
 248                                         _cert.RSA = null;
 249                                         _cert.DSA = null;
 250                                 } else  if (value is RSA)
 251                                         _cert.RSA = (RSA) value;
 252                                 else if (value is DSA)
 253                                         _cert.DSA = (DSA) value;
 254                                 else
 255                                         throw new NotSupportedException ();
 256                         }
 257                 }
 258
 259                 public PublicKey PublicKey {
 260                         get {
 261                                 if (_cert == null)
 262                                         throw new CryptographicException (empty_error);
 263
 264                                 if (_publicKey == null) {
 265                                         try {
 266                                                 _publicKey = new PublicKey (_cert);
 267                                         }
 268                                         catch (Exception e) {
 269                                                 string msg = Locale.GetText ("Unable to decode public key.");
 270                                                 throw new CryptographicException (msg, e);
 271                                         }
 272                                 }
 273                                 return _publicKey;
 274                         }
 275                 }
 276
 277                 public byte[] RawData {
 278                         get {
 279                                 if (_cert == null)
 280                                         throw new CryptographicException (empty_error);
 281
 282                                 return base.GetRawCertData ();
 283                         }
 284                 }
 285
 286                 public string SerialNumber {
 287                         get {
 288                                 if (_cert == null)
 289                                         throw new CryptographicException (empty_error);
 290
 291                                 if (_serial == null) {
 292                                         StringBuilder sb = new StringBuilder ();
 293                                         byte[] serial = _cert.SerialNumber;
 294                                         for (int i=serial.Length - 1; i >= 0; i--)
 295                                                 sb.Append (serial [i].ToString ("X2"));
 296                                         _serial = sb.ToString ();
 297                                 }
 298                                 return _serial;
 299                         }
 300                 }
 301
 302                 public Oid SignatureAlgorithm {
 303                         get {
 304                                 if (_cert == null)
 305                                         throw new CryptographicException (empty_error);
 306
 307                                 if (signature_algorithm == null)
 308                                         signature_algorithm = new Oid (_cert.SignatureAlgorithm);
 309                                 return signature_algorithm;
 310                         }
 311                 }
 312
 313                 public X500DistinguishedName SubjectName {
 314                         get {
 315                                 if (_cert == null)
 316                                         throw new CryptographicException (empty_error);
 317
 318                                 if (subject_name == null)
 319                                         subject_name = new X500DistinguishedName (_cert.GetSubjectName ().GetBytes ());
 320                                 return subject_name;
 321                         }
 322                 }
 323
 324                 public string Thumbprint {
 325                         get { return base.GetCertHashString (); }
 326                 }
 327
 328                 public int Version {
 329                         get {
 330                                 if (_cert == null)
 331                                         throw new CryptographicException (empty_error);
 332                                 return _cert.Version;
 333                         }
 334                 }
 335
 336                 // methods
 337
 338                 [MonoTODO ("always return String.Empty for UpnName, DnsFromAlternativeName and UrlName")]
 339                 public string GetNameInfo (X509NameType nameType, bool forIssuer)
 340                 {
 341                         switch (nameType) {
 342                         case X509NameType.SimpleName:
 343                                 if (_cert == null)
 344                                         throw new CryptographicException (empty_error);
 345                                 // return CN= or, if missing, the first part of the DN
 346                                 ASN1 sn = forIssuer ? _cert.GetIssuerName () : _cert.GetSubjectName ();
 347                                 ASN1 dn = Find (commonName, sn);
 348                                 if (dn != null)
 349                                         return GetValueAsString (dn);
 350                                 if (sn.Count == 0)
 351                                         return String.Empty;
 352                                 ASN1 last_entry = sn [sn.Count - 1];
 353                                 if (last_entry.Count == 0)
 354                                         return String.Empty;
 355                                 return GetValueAsString (last_entry [0]);
 356                         case X509NameType.EmailName:
 357                                 // return the E= part of the DN (if present)
 358                                 ASN1 e = Find (email, forIssuer ? _cert.GetIssuerName () : _cert.GetSubjectName ());
 359                                 if (e != null)
 360                                         return GetValueAsString (e);
 361                                 return String.Empty;
 362                         case X509NameType.UpnName:
 363                                 // FIXME - must find/create test case
 364                                 return String.Empty;
 365                         case X509NameType.DnsName:
 366                                 // return the CN= part of the DN (if present)
 367                                 ASN1 cn = Find (commonName, forIssuer ? _cert.GetIssuerName () : _cert.GetSubjectName ());
 368                                 if (cn != null)
 369                                         return GetValueAsString (cn);
 370                                 return String.Empty;
 371                         case X509NameType.DnsFromAlternativeName:
 372                                 // FIXME - must find/create test case
 373                                 return String.Empty;
 374                         case X509NameType.UrlName:
 375                                 // FIXME - must find/create test case
 376                                 return String.Empty;
 377                         default:
 378                                 throw new ArgumentException ("nameType");
 379                         }
 380                 }
 381
 382                 static byte[] commonName = { 0x55, 0x04, 0x03 };
 383                 static byte[] email = { 0x2a, 0x86, 0x48, 0x86, 0xf7, 0x0d, 0x01, 0x09, 0x01 };
 384
 385                 private ASN1 Find (byte[] oid, ASN1 dn)
 386                 {
 387                         if (dn.Count == 0)
 388                                 return null;
 389
 390                         // process SET
 391                         for (int i = 0; i < dn.Count; i++) {
 392                                 ASN1 set = dn [i];
 393                                 for (int j = 0; j < set.Count; j++) {
 394                                         ASN1 pair = set [j];
 395                                         if (pair.Count != 2)
 396                                                 continue;
 397
 398                                         ASN1 poid = pair [0];
 399                                         if (poid == null)
 400                                                 continue;
 401
 402                                         if (poid.CompareValue (oid))
 403                                                 return pair;
 404                                 }
 405                         }
 406                         return null;
 407                 }
 408
 409                 private string GetValueAsString (ASN1 pair)
 410                 {
 411                         if (pair.Count != 2)
 412                                 return String.Empty;
 413
 414                         ASN1 value = pair [1];
 415                         if ((value.Value == null) || (value.Length == 0))
 416                                 return String.Empty;
 417
 418                         if (value.Tag == 0x1E) {
 419                                 // BMPSTRING
 420                                 StringBuilder sb = new StringBuilder ();
 421                                 for (int j = 1; j < value.Value.Length; j += 2)
 422                                         sb.Append ((char)value.Value [j]);
 423                                 return sb.ToString ();
 424                         } else {
 425                                 return Encoding.UTF8.GetString (value.Value);
 426                         }
 427                 }
 428
 429                 private MX.X509Certificate ImportPkcs12 (byte[] rawData, string password)
 430                 {
 431                         MX.PKCS12 pfx = (password == null) ? new MX.PKCS12 (rawData) : new MX.PKCS12 (rawData, password);
 432                         if (pfx.Certificates.Count == 0) {
 433                                 // no certificate was found
 434                                 return null;
 435                         } else if (pfx.Keys.Count == 0) {
 436                                 // no key were found - pick the first certificate
 437                                 return pfx.Certificates [0];
 438                         } else {
 439                                 // find the certificate that match the first key
 440                                 MX.X509Certificate cert = null;
 441                                 var keypair = (pfx.Keys [0] as AsymmetricAlgorithm);
 442                                 string pubkey = keypair.ToXmlString (false);
 443                                 foreach (var c in pfx.Certificates) {
 444                                         if (((c.RSA != null) && (pubkey == c.RSA.ToXmlString (false))) ||
 445                                                 ((c.DSA != null) && (pubkey == c.DSA.ToXmlString (false)))) {
 446                                                 cert = c;
 447                                                 break;
 448                                         }
 449                                 }
 450                                 if (cert == null) {
 451                                         cert = pfx.Certificates [0]; // no match, pick first certificate without keys
 452                                 } else {
 453                                         cert.RSA = (keypair as RSA);
 454                                         cert.DSA = (keypair as DSA);
 455                                 }
 456                                 return cert;
 457                         }
 458                 }
 459
 460                 public override void Import (byte[] rawData)
 461                 {
 462                         Import (rawData, (string)null, X509KeyStorageFlags.DefaultKeySet);
 463                 }
 464
 465                 [MonoTODO ("missing KeyStorageFlags support")]
 466                 public override void Import (byte[] rawData, string password, X509KeyStorageFlags keyStorageFlags)
 467                 {
 468                         MX.X509Certificate cert = null;
 469                         if (password == null) {
 470                                 try {
 471                                         cert = new MX.X509Certificate (rawData);
 472                                 }
 473                                 catch (Exception e) {
 474                                         try {
 475                                                 cert = ImportPkcs12 (rawData, null);
 476                                         }
 477                                         catch {
 478                                                 string msg = Locale.GetText ("Unable to decode certificate.");
 479                                                 // inner exception is the original (not second) exception
 480                                                 throw new CryptographicException (msg, e);
 481                                         }
 482                                 }
 483                         } else {
 484                                 // try PKCS#12
 485                                 try {
 486                                         cert = ImportPkcs12 (rawData, password);
 487                                 }
 488                                 catch {
 489                                         // it's possible to supply a (unrequired/unusued) password
 490                                         // fix bug #79028
 491                                         cert = new MX.X509Certificate (rawData);
 492                                 }
 493                         }
 494                         // we do not have to fully re-decode the certificate since X509Certificate does not deal with keys
 495                         if (cert != null) {
 496                                 base.Import (cert.RawData, (string) null, keyStorageFlags);
 497                                 _cert = cert; // becuase base call will call Reset!
 498                         }
 499                 }
 500
 501                 [MonoTODO ("SecureString is incomplete")]
 502                 public override void Import (byte[] rawData, SecureString password, X509KeyStorageFlags keyStorageFlags)
 503                 {
 504                         Import (rawData, (string) null, keyStorageFlags);
 505                 }
 506
 507                 public override void Import (string fileName)
 508                 {
 509                         byte[] rawData = File.ReadAllBytes (fileName);
 510                         Import (rawData, (string)null, X509KeyStorageFlags.DefaultKeySet);
 511                 }
 512
 513                 [MonoTODO ("missing KeyStorageFlags support")]
 514                 public override void Import (string fileName, string password, X509KeyStorageFlags keyStorageFlags)
 515                 {
 516                         byte[] rawData = File.ReadAllBytes (fileName);
 517                         Import (rawData, password, keyStorageFlags);
 518                 }
 519
 520                 [MonoTODO ("SecureString is incomplete")]
 521                 public override void Import (string fileName, SecureString password, X509KeyStorageFlags keyStorageFlags)
 522                 {
 523                         byte[] rawData = File.ReadAllBytes (fileName);
 524                         Import (rawData, (string)null, keyStorageFlags);
 525                 }
 526
 527                 public override void Reset ()
 528                 {
 529                         _cert = null;
 530                         _archived = false;
 531                         _extensions = null;
 532                         _name = String.Empty;
 533                         _serial = null;
 534                         _publicKey = null;
 535                         issuer_name = null;
 536                         subject_name = null;
 537                         signature_algorithm = null;
 538                         base.Reset ();
 539                 }
 540
 541                 public override string ToString ()
 542                 {
 543                         if (_cert == null)
 544                                 return "System.Security.Cryptography.X509Certificates.X509Certificate2";
 545
 546                         return base.ToString (true);
 547                 }
 548
 549                 public override string ToString (bool verbose)
 550                 {
 551                         if (_cert == null)
 552                                 return "System.Security.Cryptography.X509Certificates.X509Certificate2";
 553
 554                         // the non-verbose X509Certificate2 == verbose X509Certificate
 555                         if (!verbose)
 556                                 return base.ToString (true);
 557
 558                         string nl = Environment.NewLine;
 559                         StringBuilder sb = new StringBuilder ();
 560                         sb.AppendFormat ("[Version]{0}  V{1}{0}{0}", nl, Version);
 561                         sb.AppendFormat ("[Subject]{0}  {1}{0}{0}", nl, Subject);
 562                         sb.AppendFormat ("[Issuer]{0}  {1}{0}{0}", nl, Issuer);
 563                         sb.AppendFormat ("[Serial Number]{0}  {1}{0}{0}", nl, SerialNumber);
 564                         sb.AppendFormat ("[Not Before]{0}  {1}{0}{0}", nl, NotBefore);
 565                         sb.AppendFormat ("[Not After]{0}  {1}{0}{0}", nl, NotAfter);
 566                         sb.AppendFormat ("[Thumbprint]{0}  {1}{0}{0}", nl, Thumbprint);
 567                         sb.AppendFormat ("[Signature Algorithm]{0}  {1}({2}){0}{0}", nl, SignatureAlgorithm.FriendlyName,
 568                                 SignatureAlgorithm.Value);
 569
 570                         AsymmetricAlgorithm key = PublicKey.Key;
 571                         sb.AppendFormat ("[Public Key]{0}  Algorithm: ", nl);
 572                         if (key is RSA)
 573                                 sb.Append ("RSA");
 574                         else if (key is DSA)
 575                                 sb.Append ("DSA");
 576                         else
 577                                 sb.Append (key.ToString ());
 578                         sb.AppendFormat ("{0}  Length: {1}{0}  Key Blob: ", nl, key.KeySize);
 579                         AppendBuffer (sb, PublicKey.EncodedKeyValue.RawData);
 580                         sb.AppendFormat ("{0}  Parameters: ", nl);
 581                         AppendBuffer (sb, PublicKey.EncodedParameters.RawData);
 582                         sb.Append (nl);
 583
 584                         return sb.ToString ();
 585                 }
 586
 587                 private static void AppendBuffer (StringBuilder sb, byte[] buffer)
 588                 {
 589                         if (buffer == null)
 590                                 return;
 591                         for (int i=0; i < buffer.Length; i++) {
 592                                 sb.Append (buffer [i].ToString ("x2"));
 593                                 if (i < buffer.Length - 1)
 594                                         sb.Append (" ");
 595                         }
 596                 }
 597
 598                 [MonoTODO ("by default this depends on the incomplete X509Chain")]
 599                 public bool Verify ()
 600                 {
 601                         if (_cert == null)
 602                                 throw new CryptographicException (empty_error);
 603
 604                         X509Chain chain = X509Chain.Create ();
 605                         if (!chain.Build (this))
 606                                 return false;
 607                         // TODO - check chain and other stuff ???
 608                         return true;
 609                 }
 610
 611                 // static methods
 612
 613                 private static byte[] signedData = new byte[] { 0x2a, 0x86, 0x48, 0x86, 0xf7, 0x0d, 0x01, 0x07, 0x02 };
 614
 615                 [MonoTODO ("Detection limited to Cert, Pfx, Pkcs12, Pkcs7 and Unknown")]
 616                 public static X509ContentType GetCertContentType (byte[] rawData)
 617                 {
 618                         if ((rawData == null) || (rawData.Length == 0))
 619                                 throw new ArgumentException ("rawData");
 620
 621                         X509ContentType type = X509ContentType.Unknown;
 622                         try {
 623                                 ASN1 data = new ASN1 (rawData);
 624                                 if (data.Tag != 0x30) {
 625                                         string msg = Locale.GetText ("Unable to decode certificate.");
 626                                         throw new CryptographicException (msg);
 627                                 }
 628
 629                                 if (data.Count == 0)
 630                                         return type;
 631
 632                                 if (data.Count == 3) {
 633                                         switch (data [0].Tag) {
 634                                         case 0x30:
 635                                                 // SEQUENCE / SEQUENCE / BITSTRING
 636                                                 if ((data [1].Tag == 0x30) && (data [2].Tag == 0x03))
 637                                                         type = X509ContentType.Cert;
 638                                                 break;
 639                                         case 0x02:
 640                                                 // INTEGER / SEQUENCE / SEQUENCE
 641                                                 if ((data [1].Tag == 0x30) && (data [2].Tag == 0x30))
 642                                                         type = X509ContentType.Pkcs12;
 643                                                 // note: Pfx == Pkcs12
 644                                                 break;
 645                                         }
 646                                 }
 647                                 // check for PKCS#7 (count unknown but greater than 0)
 648                                 // SEQUENCE / OID (signedData)
 649                                 if ((data [0].Tag == 0x06) && data [0].CompareValue (signedData))
 650                                         type = X509ContentType.Pkcs7;
 651                         }
 652                         catch (Exception e) {
 653                                 string msg = Locale.GetText ("Unable to decode certificate.");
 654                                 throw new CryptographicException (msg, e);
 655                         }
 656
 657                         return type;
 658                 }
 659
 660                 [MonoTODO ("Detection limited to Cert, Pfx, Pkcs12 and Unknown")]
 661                 public static X509ContentType GetCertContentType (string fileName)
 662                 {
 663                         if (fileName == null)
 664                                 throw new ArgumentNullException ("fileName");
 665                         if (fileName.Length == 0)
 666                                 throw new ArgumentException ("fileName");
 667
 668                         byte[] data = File.ReadAllBytes (fileName);
 669                         return GetCertContentType (data);
 670                 }
 671
 672                 // internal stuff because X509Certificate2 isn't complete enough
 673                 // (maybe X509Certificate3 will be better?)
 674
 675                 internal MX.X509Certificate MonoCertificate {
 676                         get { return _cert; }
 677                 }
 678
 679 #else
 680                 // HACK - this ensure the type X509Certificate2 and PrivateKey property exists in the build before
 681                 // Mono.Security.dll is built. This is required to get working client certificate in SSL/TLS
 682                 public AsymmetricAlgorithm PrivateKey {
 683                         get { return null; }
 684                 }
 685 #endif
 686         }
 687 }