mcs/class/System/Mono.Net.Security/ChainValidationHelper.cs

   1 //
   2 // System.Net.ServicePointManager
   3 //
   4 // Authors:
   5 //   Lawrence Pit (loz@cable.a2000.nl)
   6 //   Gonzalo Paniagua Javier (gonzalo@novell.com)
   7 //
   8 // Copyright (c) 2003-2010 Novell, Inc (http://www.novell.com)
   9 //
  10
  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 SECURITY_DEP
  33
  34 #if MONO_SECURITY_ALIAS
  35 extern alias MonoSecurity;
  36 #endif
  37 #if MONO_X509_ALIAS
  38 extern alias PrebuiltSystem;
  39 #endif
  40
  41 #if MONO_SECURITY_ALIAS
  42 using MonoSecurity::Mono.Security.Interface;
  43 using MSX = MonoSecurity::Mono.Security.X509;
  44 using MonoSecurity::Mono.Security.X509.Extensions;
  45 #else
  46 using Mono.Security.Interface;
  47 using MSX = Mono.Security.X509;
  48 using Mono.Security.X509.Extensions;
  49 #endif
  50 #if MONO_X509_ALIAS
  51 using XX509CertificateCollection = PrebuiltSystem::System.Security.Cryptography.X509Certificates.X509CertificateCollection;
  52 using XX509Chain = PrebuiltSystem::System.Security.Cryptography.X509Certificates.X509Chain;
  53 #else
  54 using XX509CertificateCollection = System.Security.Cryptography.X509Certificates.X509CertificateCollection;
  55 using XX509Chain = PrebuiltSystem::System.Security.Cryptography.X509Certificates.X509Chain;
  56 #endif
  57
  58 using System;
  59 using System.Net;
  60 using System.Threading;
  61 using System.Collections;
  62 using System.Collections.Generic;
  63 using System.Collections.Specialized;
  64 using System.Configuration;
  65 using System.Net.Configuration;
  66 using System.Text.RegularExpressions;
  67 using System.Security.Cryptography.X509Certificates;
  68
  69 using System.Globalization;
  70 using System.Net.Security;
  71 using System.Diagnostics;
  72
  73 namespace Mono.Net.Security
  74 {
  75         internal delegate bool ServerCertValidationCallbackWrapper (ServerCertValidationCallback callback, X509Certificate certificate, X509Chain chain, MonoSslPolicyErrors sslPolicyErrors);
  76
  77         internal class ChainValidationHelper : ICertificateValidator
  78         {
  79                 readonly object sender;
  80                 readonly MonoTlsSettings settings;
  81                 readonly MonoTlsProvider provider;
  82                 readonly ServerCertValidationCallback certValidationCallback;
  83                 readonly LocalCertSelectionCallback certSelectionCallback;
  84                 readonly ServerCertValidationCallbackWrapper callbackWrapper;
  85                 readonly MonoTlsStream tlsStream;
  86                 readonly HttpWebRequest request;
  87
  88                 static bool is_macosx;
  89                 static bool is_mobile;
  90 #if !MOBILE
  91                 static X509RevocationMode revocation_mode;
  92 #endif
  93
  94                 static ChainValidationHelper ()
  95                 {
  96 #if MONOTOUCH
  97                         is_macosx = true;
  98                         is_mobile = true;
  99 #elif MONODROID
 100                         is_macosx = false;
 101                         is_mobile = true;
 102 #else
 103                         is_macosx = System.IO.File.Exists (OSX509Certificates.SecurityLibrary);
 104                         is_mobile = false;
 105 #endif
 106
 107 #if !MOBILE
 108                         revocation_mode = X509RevocationMode.NoCheck;
 109                         try {
 110                                 string str = Environment.GetEnvironmentVariable ("MONO_X509_REVOCATION_MODE");
 111                                 if (String.IsNullOrEmpty (str))
 112                                         return;
 113                                 revocation_mode = (X509RevocationMode)Enum.Parse (typeof(X509RevocationMode), str, true);
 114                         } catch {
 115                         }
 116 #endif
 117                 }
 118
 119                 internal static ICertificateValidator GetDefaultValidator (MonoTlsProvider provider, MonoTlsSettings settings)
 120                 {
 121                         if (settings == null)
 122                                 return new ChainValidationHelper (provider, null, false, null, null);
 123                         if (settings.CertificateValidator != null)
 124                                 return settings.CertificateValidator;
 125                         return new ChainValidationHelper (provider, settings, false, null, null);
 126                 }
 127
 128 #region SslStream support
 129
 130                 /*
 131                  * This is a hack which is used in SslStream - see ReferenceSources/SslStream.cs for details.
 132                  */
 133                 internal static ChainValidationHelper CloneWithCallbackWrapper (MonoTlsProvider provider, ref MonoTlsSettings settings, ServerCertValidationCallbackWrapper wrapper)
 134                 {
 135                         var helper = (ChainValidationHelper)settings.CertificateValidator;
 136                         if (helper == null)
 137                                 helper = new ChainValidationHelper (provider, settings, true, null, wrapper);
 138                         else
 139                                 helper = new ChainValidationHelper (helper, provider, settings, wrapper);
 140                         settings = helper.settings;
 141                         return helper;
 142                 }
 143
 144                 internal static bool InvokeCallback (ServerCertValidationCallback callback, object sender, X509Certificate certificate, X509Chain chain, MonoSslPolicyErrors sslPolicyErrors)
 145                 {
 146                         return callback.Invoke (sender, certificate, chain, (SslPolicyErrors)sslPolicyErrors);
 147                 }
 148
 149 #endregion
 150
 151                 ChainValidationHelper (ChainValidationHelper other, MonoTlsProvider provider, MonoTlsSettings settings, ServerCertValidationCallbackWrapper callbackWrapper = null)
 152                 {
 153                         sender = other.sender;
 154                         certValidationCallback = other.certValidationCallback;
 155                         certSelectionCallback = other.certSelectionCallback;
 156                         tlsStream = other.tlsStream;
 157                         request = other.request;
 158
 159                         this.provider = provider;
 160                         this.settings = settings = settings.CloneWithValidator (this);
 161                         this.callbackWrapper = callbackWrapper;
 162                 }
 163
 164                 internal static ChainValidationHelper Create (MonoTlsProvider provider, ref MonoTlsSettings settings, MonoTlsStream stream)
 165                 {
 166                         var helper = new ChainValidationHelper (provider, settings, true, stream, null);
 167                         settings = helper.settings;
 168                         return helper;
 169                 }
 170
 171                 ChainValidationHelper (MonoTlsProvider provider, MonoTlsSettings settings, bool cloneSettings, MonoTlsStream stream, ServerCertValidationCallbackWrapper callbackWrapper)
 172                 {
 173                         if (cloneSettings)
 174                                 settings = settings.CloneWithValidator (this);
 175
 176                         this.provider = provider;
 177                         this.settings = settings;
 178                         this.tlsStream = stream;
 179                         this.callbackWrapper = callbackWrapper;
 180
 181                         var fallbackToSPM = false;
 182
 183                         if (settings != null) {
 184                                 if (settings.RemoteCertificateValidationCallback != null) {
 185                                         var callback = Private.CallbackHelpers.MonoToPublic (settings.RemoteCertificateValidationCallback);
 186                                         certValidationCallback = new ServerCertValidationCallback (callback);
 187                                 }
 188                                 certSelectionCallback = Private.CallbackHelpers.MonoToInternal (settings.ClientCertificateSelectionCallback);
 189                                 fallbackToSPM = settings.UseServicePointManagerCallback;
 190                         }
 191
 192                         if (stream != null) {
 193                                 this.request = stream.Request;
 194                                 this.sender = request;
 195
 196                                 if (certValidationCallback == null)
 197                                         certValidationCallback = request.ServerCertValidationCallback;
 198                                 if (certSelectionCallback == null)
 199                                         certSelectionCallback = new LocalCertSelectionCallback (DefaultSelectionCallback);
 200
 201                                 if (settings == null)
 202                                         fallbackToSPM = true;
 203                         }
 204
 205                         if (fallbackToSPM && certValidationCallback == null)
 206                                 certValidationCallback = ServicePointManager.ServerCertValidationCallback;
 207                 }
 208
 209                 static X509Certificate DefaultSelectionCallback (string targetHost, XX509CertificateCollection localCertificates, X509Certificate remoteCertificate, string[] acceptableIssuers)
 210                 {
 211                         X509Certificate clientCertificate;
 212                         if (localCertificates == null || localCertificates.Count == 0)
 213                                 clientCertificate = null;
 214                         else
 215                                 clientCertificate = localCertificates [0];
 216                         return clientCertificate;
 217                 }
 218
 219                 public MonoTlsProvider Provider {
 220                         get { return provider; }
 221                 }
 222
 223                 public MonoTlsSettings Settings {
 224                         get { return settings; }
 225                 }
 226
 227                 public bool HasCertificateSelectionCallback {
 228                         get { return certSelectionCallback != null; }
 229                 }
 230
 231                 public bool SelectClientCertificate (
 232                         string targetHost, XX509CertificateCollection localCertificates, X509Certificate remoteCertificate,
 233                         string[] acceptableIssuers, out X509Certificate clientCertificate)
 234                 {
 235                         if (certSelectionCallback == null) {
 236                                 clientCertificate = null;
 237                                 return false;
 238                         }
 239                         clientCertificate = certSelectionCallback (targetHost, localCertificates, remoteCertificate, acceptableIssuers);
 240                         return true;
 241                 }
 242
 243                 internal X509Certificate SelectClientCertificate (
 244                         string targetHost, XX509CertificateCollection localCertificates, X509Certificate remoteCertificate,
 245                         string[] acceptableIssuers)
 246                 {
 247                         if (certSelectionCallback == null)
 248                                 return null;
 249                         return certSelectionCallback (targetHost, localCertificates, remoteCertificate, acceptableIssuers);
 250                 }
 251
 252                 internal bool ValidateClientCertificate (X509Certificate certificate, MonoSslPolicyErrors errors)
 253                 {
 254                         var certs = new XX509CertificateCollection ();
 255                         certs.Add (new X509Certificate2 (certificate.GetRawCertData ()));
 256
 257                         var result = ValidateChain (string.Empty, true, certs, (SslPolicyErrors)errors);
 258                         if (result == null)
 259                                 return false;
 260
 261                         return result.Trusted && !result.UserDenied;
 262                 }
 263
 264                 public ValidationResult ValidateCertificate (string host, bool serverMode, XX509CertificateCollection certs)
 265                 {
 266                         try {
 267                                 var result = ValidateChain (host, serverMode, certs, 0);
 268                                 if (tlsStream != null)
 269                                         tlsStream.CertificateValidationFailed = result == null || !result.Trusted || result.UserDenied;
 270                                 return result;
 271                         } catch {
 272                                 if (tlsStream != null)
 273                                         tlsStream.CertificateValidationFailed = true;
 274                                 throw;
 275                         }
 276                 }
 277
 278                 ValidationResult ValidateChain (string host, bool server, XX509CertificateCollection certs, SslPolicyErrors errors)
 279                 {
 280                         // user_denied is true if the user callback is called and returns false
 281                         bool user_denied = false;
 282                         bool result = false;
 283
 284                         var hasCallback = certValidationCallback != null || callbackWrapper != null;
 285
 286                         X509Certificate leaf;
 287                         if (certs == null || certs.Count == 0)
 288                                 leaf = null;
 289                         else
 290                                 leaf = certs [0];
 291
 292                         if (tlsStream != null)
 293                                 request.ServicePoint.SetServerCertificate (leaf);
 294
 295                         if (leaf == null) {
 296                                 errors |= SslPolicyErrors.RemoteCertificateNotAvailable;
 297                                 if (hasCallback) {
 298                                         if (callbackWrapper != null)
 299                                                 result = callbackWrapper.Invoke (certValidationCallback, leaf, null, (MonoSslPolicyErrors)errors);
 300                                         else
 301                                                 result = certValidationCallback.Invoke (sender, leaf, null, errors);
 302                                         user_denied = !result;
 303                                 }
 304                                 return new ValidationResult (result, user_denied, 0, (MonoSslPolicyErrors)errors);
 305                         }
 306
 307                         ICertificatePolicy policy = ServicePointManager.GetLegacyCertificatePolicy ();
 308
 309                         int status11 = 0; // Error code passed to the obsolete ICertificatePolicy callback
 310                         X509Chain chain = null;
 311
 312                         bool wantsChain = SystemCertificateValidator.NeedsChain (settings);
 313                         if (!wantsChain && hasCallback) {
 314                                 if (settings == null || settings.CallbackNeedsCertificateChain)
 315                                         wantsChain = true;
 316                         }
 317
 318                         if (wantsChain)
 319                                 chain = SystemCertificateValidator.CreateX509Chain (certs);
 320
 321                         if (wantsChain || SystemCertificateValidator.NeedsChain (settings))
 322                                 SystemCertificateValidator.BuildX509Chain (certs, chain, ref errors, ref status11);
 323
 324                         bool providerValidated = false;
 325                         if (provider != null && provider.HasCustomSystemCertificateValidator) {
 326                                 var xerrors = (MonoSslPolicyErrors)errors;
 327                                 var xchain = (XX509Chain)(object)chain;
 328                                 providerValidated = provider.InvokeSystemCertificateValidator (this, host, server, certs, xchain, out result, ref xerrors, ref status11);
 329                                 errors = (SslPolicyErrors)xerrors;
 330                         }
 331
 332                         if (!providerValidated)
 333                                 result = SystemCertificateValidator.Evaluate (settings, host, certs, chain, ref errors, ref status11);
 334
 335                         if (policy != null && (!(policy is DefaultCertificatePolicy) || certValidationCallback == null)) {
 336                                 ServicePoint sp = null;
 337                                 if (request != null)
 338                                         sp = request.ServicePointNoLock;
 339                                 if (status11 == 0 && errors != 0) {
 340                                         // TRUST_E_FAIL
 341                                         status11 = unchecked ((int)0x800B010B);
 342                                 }
 343
 344                                 // pre 2.0 callback
 345                                 result = policy.CheckValidationResult (sp, leaf, request, status11);
 346                                 user_denied = !result && !(policy is DefaultCertificatePolicy);
 347                         }
 348                         // If there's a 2.0 callback, it takes precedence
 349                         if (hasCallback) {
 350                                 if (callbackWrapper != null)
 351                                         result = callbackWrapper.Invoke (certValidationCallback, leaf, chain, (MonoSslPolicyErrors)errors);
 352                                 else
 353                                         result = certValidationCallback.Invoke (sender, leaf, chain, errors);
 354                                 user_denied = !result;
 355                         }
 356                         return new ValidationResult (result, user_denied, status11, (MonoSslPolicyErrors)errors);
 357                 }
 358
 359                 public bool InvokeSystemValidator (string targetHost, bool serverMode, XX509CertificateCollection certificates, XX509Chain xchain, ref MonoSslPolicyErrors xerrors, ref int status11)
 360                 {
 361                         X509Chain chain = (X509Chain)(object)xchain;
 362                         var errors = (SslPolicyErrors)xerrors;
 363                         var result = SystemCertificateValidator.Evaluate (settings, targetHost, certificates, chain, ref errors, ref status11);
 364                         xerrors = (MonoSslPolicyErrors)errors;
 365                         return result;
 366                 }
 367         }
 368 }
 369 #endif
 370