mcs/class/Mono.Http/Mono.Http.Modules/AuthenticationModule.cs

   1 //
   2 // Abstract Authentication implementation
   3 //
   4 // Authors:
   5 //      Greg Reinacker (gregr@rassoc.com)
   6 //      Sebastien Pouliot (spouliot@motus.com)
   7 //
   8 // Copyright 2002-2003 Greg Reinacker, Reinacker & Associates, Inc. All rights reserved.
   9 // Portions (C) 2003 Motus Technologies Inc. (http://www.motus.com)
  10 //
  11 // Based on "DigestAuthenticationModule.cs". Original source code available at
  12 // http://www.rassoc.com/gregr/weblog/stories/2002/07/09/webServicesSecurityHttpDigestAuthenticationWithoutActiveDirectory.html
  13 //
  14
  15 //
  16 // Permission is hereby granted, free of charge, to any person obtaining
  17 // a copy of this software and associated documentation files (the
  18 // "Software"), to deal in the Software without restriction, including
  19 // without limitation the rights to use, copy, modify, merge, publish,
  20 // distribute, sublicense, and/or sell copies of the Software, and to
  21 // permit persons to whom the Software is furnished to do so, subject to
  22 // the following conditions:
  23 //
  24 // The above copyright notice and this permission notice shall be
  25 // included in all copies or substantial portions of the Software.
  26 //
  27 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  28 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  29 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  30 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  31 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  32 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  33 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  34 //
  35
  36 using System;
  37 using System.Configuration;
  38 using System.Web;
  39
  40 namespace Mono.Http.Modules
  41 {
  42         abstract public class AuthenticationModule : IHttpModule
  43         {
  44                 string authMethod;
  45
  46                 public AuthenticationModule (string authenticationMethod)
  47                 {
  48                         authMethod = authenticationMethod;
  49                 }
  50
  51                 public string AuthenticationMethod {
  52                         get { return authMethod; }
  53                 }
  54
  55                 #region IHttpModule Members
  56
  57                 public virtual void Init (HttpApplication context)
  58                 {
  59                         context.AuthenticateRequest += new EventHandler (this.OnAuthenticateRequest);
  60                         context.EndRequest += new EventHandler (this.OnEndRequest);
  61                 }
  62
  63                 public virtual void Dispose () {}
  64
  65                 #endregion
  66
  67                 #region Event Handlers
  68
  69                 public virtual void OnAuthenticateRequest (object source, EventArgs eventArgs)
  70                 {
  71                         if (!AuthenticationRequired)
  72                                 return;
  73
  74                         HttpApplication app = (HttpApplication) source;
  75                         string authdata = Authorization (app, AuthenticationMethod);
  76                         if ((authdata == null) || (!AcceptCredentials (app, authdata))) {
  77                                 DenyAccess (app);
  78                                 return;
  79                         }
  80                 }
  81
  82                 abstract public void OnEndRequest (object source, EventArgs eventArgs);
  83
  84                 #endregion
  85
  86                 abstract protected bool AcceptCredentials (HttpApplication app, string authentication);
  87
  88                 protected bool AuthenticationRequired {
  89                         get { return (AuthenticationMethod == ConfigurationSettings.AppSettings ["Authentication"]); }
  90                 }
  91
  92                 protected void DenyAccess (HttpApplication app)
  93                 {
  94                         app.Response.StatusCode = 401;
  95                         app.Response.StatusDescription = "Access Denied";
  96                         // Write to response stream as well, to give user visual
  97                         // indication of error during development
  98                         app.Response.Write ("401 Access Denied");
  99                         app.CompleteRequest ();
 100                 }
 101
 102                 protected string Authorization (HttpApplication app, string authenticationMethod)
 103                 {
 104                         string autz = app.Request.Headers ["Authorization"];
 105                         if ((autz == null) || (autz.Length == 0)) {
 106                                 // No credentials; anonymous request
 107                                 return null;
 108                         }
 109
 110                         if (autz.ToUpper ().StartsWith (authenticationMethod.ToUpper ())) {
 111                                 return autz.Substring (authenticationMethod.Length + 1);
 112                         }
 113
 114                         return null;
 115                 }
 116         }
 117 }
 118