mcs/class/System.Web/System.Web.Handlers/AssemblyResourceLoader.cs

   1 //
   2 // System.Web.Handlers.AssemblyResourceLoader
   3 //
   4 // Authors:
   5 //      Ben Maurer (bmaurer@users.sourceforge.net)
   6 //      Marek Habersack <grendel@twistedcode.net>
   7 //
   8 // (C) 2003 Ben Maurer
   9 // (C) 2010 Novell, Inc (http://novell.com/)
  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 using System.Web.UI;
  33 using System.Globalization;
  34 using System.Reflection;
  35 using System.IO;
  36 using System.Resources;
  37 using System.Collections;
  38 using System.Collections.Generic;
  39 using System.Collections.Specialized;
  40 using System.Security.Cryptography;
  41 using System.Text;
  42 using System.Text.RegularExpressions;
  43 using System.Threading;
  44 using System.Web.Configuration;
  45 using System.Web.Util;
  46
  47 namespace System.Web.Handlers
  48 {
  49 #if SYSTEM_WEB_EXTENSIONS
  50         partial class ScriptResourceHandler
  51         {
  52                 const string HandlerFileName = "ScriptResource.axd";
  53                 static Assembly currAsm = typeof (ScriptResourceHandler).Assembly;
  54 #else
  55         public sealed class AssemblyResourceLoader : IHttpHandler
  56         {
  57                 const string HandlerFileName = "WebResource.axd";
  58                 static Assembly currAsm = typeof (AssemblyResourceLoader).Assembly;
  59 #endif
  60                 const char QueryParamSeparator = '&';
  61
  62                 static readonly Dictionary <string, AssemblyEmbeddedResources> _embeddedResources = new Dictionary <string, AssemblyEmbeddedResources> (StringComparer.Ordinal);
  63                 static readonly ReaderWriterLockSlim _embeddedResourcesLock = new ReaderWriterLockSlim ();
  64                 static readonly ReaderWriterLockSlim _stringHashCacheLock = new ReaderWriterLockSlim ();
  65                 static readonly Dictionary <string, string> stringHashCache = new Dictionary <string, string> (StringComparer.Ordinal);
  66
  67                 [ThreadStatic]
  68                 static KeyedHashAlgorithm hashAlg;
  69                 static bool canReuseHashAlg = true;
  70
  71                 static KeyedHashAlgorithm ReusableHashAlgorithm {
  72                         get {
  73                                 if (!canReuseHashAlg)
  74                                         return null;
  75
  76                                 if (hashAlg == null) {
  77                                         MachineKeySection mks = MachineKeySection.Config;
  78                                         hashAlg = MachineKeySectionUtils.GetValidationAlgorithm (mks);
  79                                         if (!hashAlg.CanReuseTransform) {
  80                                                 canReuseHashAlg = false;
  81                                                 hashAlg = null;
  82                                                 return null;
  83                                         }
  84                                         hashAlg.Key = MachineKeySectionUtils.GetValidationKey (mks);
  85                                 }
  86
  87                                 if (hashAlg != null)
  88                                         hashAlg.Initialize ();
  89
  90                                 return hashAlg;
  91                         }
  92                 }
  93
  94                 static string GetStringHash (KeyedHashAlgorithm kha, string str)
  95                 {
  96                         if (String.IsNullOrEmpty (str))
  97                                 return String.Empty;
  98
  99                         string result;
 100                         try {
 101                                 _stringHashCacheLock.EnterUpgradeableReadLock ();
 102                                 if (stringHashCache.TryGetValue (str, out result))
 103                                         return result;
 104
 105                                 try {
 106                                         _stringHashCacheLock.EnterWriteLock ();
 107                                         if (stringHashCache.TryGetValue (str, out result))
 108                                                 return result;
 109
 110                                         result = Convert.ToBase64String (kha.ComputeHash (Encoding.UTF8.GetBytes (str)));
 111                                         stringHashCache.Add (str, result);
 112                                 } finally {
 113                                         _stringHashCacheLock.ExitWriteLock ();
 114                                 }
 115                         } finally {
 116                                 _stringHashCacheLock.ExitUpgradeableReadLock ();
 117                         }
 118
 119                         return result;
 120                 }
 121
 122                 static void InitEmbeddedResourcesUrls (KeyedHashAlgorithm kha, Assembly assembly, string assemblyName, string assemblyHash, AssemblyEmbeddedResources entry)
 123                 {
 124                         WebResourceAttribute [] attrs = (WebResourceAttribute []) assembly.GetCustomAttributes (typeof (WebResourceAttribute), false);
 125                         WebResourceAttribute attr;
 126                         string apath = assembly.Location;
 127                         for (int i = 0; i < attrs.Length; i++) {
 128                                 attr = attrs [i];
 129                                 string resourceName = attr.WebResource;
 130                                 if (!String.IsNullOrEmpty (resourceName)) {
 131                                         string resourceNameHash = GetStringHash (kha, resourceName);
 132 #if SYSTEM_WEB_EXTENSIONS
 133                                         bool debug = resourceName.EndsWith (".debug.js", StringComparison.OrdinalIgnoreCase);
 134                                         string dbgTail = debug ? "d" : String.Empty;
 135                                         string rkNoNotify = resourceNameHash + "f" + dbgTail;
 136                                         string rkNotify = resourceNameHash + "t" + dbgTail;
 137
 138                                         if (!entry.Resources.ContainsKey (rkNoNotify)) {
 139                                                 var er = new EmbeddedResource () {
 140                                                         Name = resourceName,
 141                                                         Attribute = attr,
 142                                                         Url = CreateResourceUrl (kha, assemblyName, assemblyHash, apath, rkNoNotify, debug, false, true)
 143                                                 };
 144
 145                                                 entry.Resources.Add (rkNoNotify, er);
 146                                         }
 147
 148                                         if (!entry.Resources.ContainsKey (rkNotify)) {
 149                                                 var er = new EmbeddedResource () {
 150                                                         Name = resourceName,
 151                                                         Attribute = attr,
 152                                                         Url = CreateResourceUrl (kha, assemblyName, assemblyHash, apath, rkNotify, debug, true, true)
 153                                                 };
 154
 155                                                 entry.Resources.Add (rkNotify, er);
 156                                         }
 157 #else
 158                                         if (!entry.Resources.ContainsKey (resourceNameHash)) {
 159                                                 var er = new EmbeddedResource () {
 160                                                         Name = resourceName,
 161                                                         Attribute = attr,
 162                                                         Url = CreateResourceUrl (kha, assemblyName, assemblyHash, apath, resourceNameHash, false, false, true)
 163                                                 };
 164                                                 entry.Resources.Add (resourceNameHash, er);
 165                                         }
 166 #endif
 167                                 }
 168                         }
 169                 }
 170
 171 #if !SYSTEM_WEB_EXTENSIONS
 172                 internal static string GetResourceUrl (Type type, string resourceName)
 173                 {
 174                         return GetResourceUrl (type.Assembly, resourceName, false);
 175                 }
 176 #endif
 177                 static EmbeddedResource DecryptAssemblyResource (string val, out AssemblyEmbeddedResources entry)
 178                 {
 179                         entry = null;
 180
 181                         string[] parts = val.Split ('_');
 182                         if (parts.Length != 3)
 183                                 return null;
 184
 185                         string asmNameHash = parts [0];
 186                         string resNameHash = parts [1];
 187                         try {
 188                                 _embeddedResourcesLock.EnterReadLock ();
 189                                 if (!_embeddedResources.TryGetValue (asmNameHash, out entry) || entry == null)
 190                                         return null;
 191
 192                                 EmbeddedResource res;
 193                                 if (!entry.Resources.TryGetValue (resNameHash, out res) || res == null) {
 194 #if SYSTEM_WEB_EXTENSIONS
 195                                         bool debug = parts [2] == "t";
 196                                         if (!debug)
 197                                                 return null;
 198
 199                                         if (!entry.Resources.TryGetValue (resNameHash.Substring (0, resNameHash.Length - 1), out res))
 200                                                 return null;
 201 #else
 202                                         return null;
 203 #endif
 204                                 }
 205
 206                                 return res;
 207                         } finally {
 208                                 _embeddedResourcesLock.ExitReadLock ();
 209                         }
 210                 }
 211
 212                 static void GetAssemblyNameAndHashes (KeyedHashAlgorithm kha, Assembly assembly, string resourceName, out string assemblyName, out string assemblyNameHash, out string resourceNameHash)
 213                 {
 214                         assemblyName = assembly == currAsm ? "s" : assembly.GetName ().FullName;
 215                         assemblyNameHash = GetStringHash (kha, assemblyName);
 216                         resourceNameHash = GetStringHash (kha, resourceName);
 217                 }
 218
 219                 // MUST be called with the _embeddedResourcesLock taken in the upgradeable read lock mode
 220                 static AssemblyEmbeddedResources GetAssemblyEmbeddedResource (KeyedHashAlgorithm kha, Assembly assembly, string assemblyNameHash, string assemblyName)
 221                 {
 222                         AssemblyEmbeddedResources entry;
 223
 224                         if (!_embeddedResources.TryGetValue (assemblyNameHash, out entry) || entry == null) {
 225                                 try {
 226                                         _embeddedResourcesLock.EnterWriteLock ();
 227                                         entry = new AssemblyEmbeddedResources () {
 228                                                         AssemblyName = assemblyName
 229                                                                 };
 230                                         InitEmbeddedResourcesUrls (kha, assembly, assemblyName, assemblyNameHash, entry);
 231                                         _embeddedResources.Add (assemblyNameHash, entry);
 232                                 } finally {
 233                                         _embeddedResourcesLock.ExitWriteLock ();
 234                                 }
 235                         }
 236
 237                         return entry;
 238                 }
 239
 240                 internal static string GetResourceUrl (Assembly assembly, string resourceName, bool notifyScriptLoaded)
 241                 {
 242                         if (assembly == null)
 243                                 return String.Empty;
 244
 245                         KeyedHashAlgorithm kha = ReusableHashAlgorithm;
 246                         if (kha != null) {
 247                                 return GetResourceUrl (kha, assembly, resourceName, notifyScriptLoaded);
 248                         } else {
 249                                 MachineKeySection mks = MachineKeySection.Config;
 250                                 using (kha = MachineKeySectionUtils.GetValidationAlgorithm (mks)) {
 251                                         kha.Key = MachineKeySectionUtils.GetValidationKey (mks);
 252                                         return GetResourceUrl (kha, assembly, resourceName, notifyScriptLoaded);
 253                                 }
 254                         }
 255                 }
 256
 257                 static string GetResourceUrl (KeyedHashAlgorithm kha, Assembly assembly, string resourceName, bool notifyScriptLoaded)
 258                 {
 259                         string assemblyName;
 260                         string assemblyNameHash;
 261                         string resourceNameHash;
 262
 263                         GetAssemblyNameAndHashes (kha, assembly, resourceName, out assemblyName, out assemblyNameHash, out resourceNameHash);
 264                         bool debug = false;
 265                         string url;
 266                         AssemblyEmbeddedResources entry;
 267                         bool includeTimeStamp = true;
 268
 269                         try {
 270                                 _embeddedResourcesLock.EnterUpgradeableReadLock ();
 271                                 entry = GetAssemblyEmbeddedResource (kha, assembly, assemblyNameHash, assemblyName);
 272                                 string lookupKey;
 273 #if SYSTEM_WEB_EXTENSIONS
 274                                 debug = resourceName.EndsWith (".debug.js", StringComparison.OrdinalIgnoreCase);
 275                                 string dbgTail = debug ? "d" : String.Empty;
 276                                 lookupKey = resourceNameHash + (notifyScriptLoaded ? "t" : "f") + dbgTail;
 277                                 CheckIfResourceIsCompositeScript (resourceName, ref includeTimeStamp);
 278 #else
 279                                 lookupKey = resourceNameHash;
 280 #endif
 281                                 EmbeddedResource res;
 282                                 if (entry.Resources.TryGetValue (lookupKey, out res) && res != null)
 283                                         url = res.Url;
 284                                 else {
 285 #if SYSTEM_WEB_EXTENSIONS
 286                                         if (debug) {
 287                                                 resourceNameHash = GetStringHash (kha, resourceName.Substring (0, resourceName.Length - 9) + ".js");
 288                                                 lookupKey = resourceNameHash + (notifyScriptLoaded ? "t" : "f");
 289
 290                                                 if (entry.Resources.TryGetValue (lookupKey, out res) && res != null)
 291                                                         url = res.Url;
 292                                                 else
 293                                                         url = null;
 294                                         } else
 295 #endif
 296                                                 url = null;
 297                                 }
 298                         } finally {
 299                                 _embeddedResourcesLock.ExitUpgradeableReadLock ();
 300                         }
 301
 302                         if (url == null)
 303                                 url = CreateResourceUrl (kha, assemblyName, assemblyNameHash, assembly.Location, resourceNameHash, debug, notifyScriptLoaded, includeTimeStamp);
 304
 305                         return url;
 306                 }
 307
 308                 static string CreateResourceUrl (KeyedHashAlgorithm kha, string assemblyName, string assemblyNameHash, string assemblyPath, string resourceNameHash, bool debug,
 309                                                  bool notifyScriptLoaded, bool includeTimeStamp)
 310                 {
 311                         string atime = String.Empty;
 312                         string extra = String.Empty;
 313 #if SYSTEM_WEB_EXTENSIONS
 314                         extra = QueryParamSeparator + "n=" + (notifyScriptLoaded ? "t" : "f");
 315 #endif
 316
 317                         if (includeTimeStamp) {
 318                                 if (!String.IsNullOrEmpty (assemblyPath) && File.Exists (assemblyPath))
 319                                         atime = QueryParamSeparator + "t=" + File.GetLastWriteTimeUtc (assemblyPath).Ticks;
 320                                 else
 321                                         atime = QueryParamSeparator + "t=" + DateTime.UtcNow.Ticks;
 322                         }
 323                         string d = HttpUtility.UrlEncode (assemblyNameHash + "_" + resourceNameHash +  (debug ? "_t" : "_f"));
 324                         string href = HandlerFileName + "?d=" + d + atime + extra;
 325                         HttpContext ctx = HttpContext.Current;
 326                         HttpRequest req = ctx != null ? ctx.Request : null;
 327                         if (req != null) {
 328                                 string appPath = VirtualPathUtility.AppendTrailingSlash (req.ApplicationPath);
 329                                 href = appPath + href;
 330                         }
 331
 332                         return href;
 333                 }
 334
 335                 bool HasIfModifiedSince (HttpRequest request, out DateTime modified)
 336                 {
 337                         string modif_since = request.Headers ["If-Modified-Since"];
 338                         if (String.IsNullOrEmpty (modif_since)) {
 339                                 modified = DateTime.MinValue;
 340                                 return false;
 341                         }
 342
 343                         try {
 344                                 if (DateTime.TryParseExact (modif_since, "r", null, 0, out modified))
 345                                         return true;
 346                         } catch {
 347                                 modified = DateTime.MinValue;
 348                         }
 349
 350                         return false;
 351                 }
 352
 353                 void RespondWithNotModified (HttpContext context)
 354                 {
 355                         HttpResponse response = context.Response;
 356                         response.Clear ();
 357                         response.StatusCode = 304;
 358                         response.ContentType = null;
 359                         context.ApplicationInstance.CompleteRequest ();
 360                 }
 361
 362                 void SendEmbeddedResource (HttpContext context, out EmbeddedResource res, out Assembly assembly)
 363                 {
 364                         HttpRequest request = context.Request;
 365                         NameValueCollection queryString = request.QueryString;
 366
 367                         // val is URL-encoded, which means every + has been replaced with ' ', we
 368                         // need to revert that or the base64 conversion will fail.
 369                         string d = queryString ["d"];
 370                         if (!String.IsNullOrEmpty (d))
 371                                 d = d.Replace (' ', '+');
 372
 373                         AssemblyEmbeddedResources entry;
 374                         res = DecryptAssemblyResource (d, out entry);
 375                         WebResourceAttribute wra = res != null ? res.Attribute : null;
 376                         if (wra == null)
 377                                 throw new HttpException (404, "Resource not found");
 378
 379                         if (entry.AssemblyName == "s")
 380                                 assembly = currAsm;
 381                         else
 382                                 assembly = Assembly.Load (entry.AssemblyName);
 383
 384                         DateTime modified;
 385                         if (HasIfModifiedSince (request, out modified)) {
 386                                 if (File.GetLastWriteTimeUtc (assembly.Location) <= modified) {
 387                                         RespondWithNotModified (context);
 388                                         return;
 389                                 }
 390                         }
 391
 392                         HttpResponse response = context.Response;
 393                         response.ContentType = wra.ContentType;
 394
 395                         DateTime utcnow = DateTime.UtcNow;
 396                         response.Headers.Add ("Last-Modified", utcnow.ToString ("r"));
 397                         response.ExpiresAbsolute = utcnow.AddYears (1);
 398                         response.CacheControl = "public";
 399
 400                         Stream s = assembly.GetManifestResourceStream (res.Name);
 401                         if (s == null)
 402                                 throw new HttpException (404, "Resource " + res.Name + " not found");
 403
 404                         if (wra.PerformSubstitution) {
 405                                 using (StreamReader r = new StreamReader (s)) {
 406                                         TextWriter w = response.Output;
 407                                         new PerformSubstitutionHelper (assembly).PerformSubstitution (r, w);
 408                                 }
 409                         } else if (response.OutputStream is HttpResponseStream) {
 410                                 UnmanagedMemoryStream st = (UnmanagedMemoryStream) s;
 411                                 HttpResponseStream hstream = (HttpResponseStream) response.OutputStream;
 412                                 unsafe {
 413                                         hstream.WritePtr (new IntPtr (st.PositionPointer), (int) st.Length);
 414                                 }
 415                         } else {
 416                                 byte [] buf = new byte [1024];
 417                                 Stream output = response.OutputStream;
 418                                 int c;
 419                                 do {
 420                                         c = s.Read (buf, 0, 1024);
 421                                         output.Write (buf, 0, c);
 422                                 } while (c > 0);
 423                         }
 424                 }
 425
 426 #if !SYSTEM_WEB_EXTENSIONS
 427                 void System.Web.IHttpHandler.ProcessRequest (HttpContext context)
 428                 {
 429                         EmbeddedResource res;
 430                         Assembly assembly;
 431
 432                         SendEmbeddedResource (context, out res, out assembly);
 433                 }
 434 #endif
 435                 sealed class PerformSubstitutionHelper
 436                 {
 437                         readonly Assembly _assembly;
 438                         static readonly Regex _regex = new Regex (@"\<%=[ ]*WebResource[ ]*\([ ]*""([^""]+)""[ ]*\)[ ]*%\>");
 439
 440                         public PerformSubstitutionHelper (Assembly assembly) {
 441                                 _assembly = assembly;
 442                         }
 443
 444                         public void PerformSubstitution (TextReader reader, TextWriter writer) {
 445                                 string line = reader.ReadLine ();
 446                                 while (line != null) {
 447                                         if (line.Length > 0 && _regex.IsMatch (line))
 448                                                 line = _regex.Replace (line, new MatchEvaluator (PerformSubstitutionReplace));
 449                                         writer.WriteLine (line);
 450                                         line = reader.ReadLine ();
 451                                 }
 452                         }
 453
 454                         string PerformSubstitutionReplace (Match m) {
 455                                 string resourceName = m.Groups [1].Value;
 456 #if SYSTEM_WEB_EXTENSIONS
 457                                 return ScriptResourceHandler.GetResourceUrl (_assembly, resourceName, false);
 458 #else
 459                                 return AssemblyResourceLoader.GetResourceUrl (_assembly, resourceName, false);
 460 #endif
 461                         }
 462                 }
 463
 464 #if !SYSTEM_WEB_EXTENSIONS
 465                 bool System.Web.IHttpHandler.IsReusable { get { return true; } }
 466 #endif
 467                 sealed class EmbeddedResource
 468                 {
 469                         public string Name;
 470                         public string Url;
 471                         public WebResourceAttribute Attribute;
 472                 }
 473
 474                 sealed class AssemblyEmbeddedResources
 475                 {
 476                         public string AssemblyName = String.Empty;
 477                         public Dictionary <string, EmbeddedResource> Resources = new Dictionary <string, EmbeddedResource> (StringComparer.Ordinal);
 478                 }
 479         }
 480 }
 481