mcs/class/referencesource/System.Runtime.Serialization/System/Runtime/Serialization/SurrogateDataContract.cs

   1 //-----------------------------------------------------------------------------
   2 // Copyright (c) Microsoft Corporation.  All rights reserved.
   3 //-----------------------------------------------------------------------------
   4 namespace System.Runtime.Serialization
   5 {
   6     using System;
   7     using System.Security;
   8     using System.Security.Permissions;
   9     using System.Runtime.CompilerServices;
  10
  11 #if USE_REFEMIT
  12     public sealed class SurrogateDataContract : DataContract
  13 #else
  14     internal sealed class SurrogateDataContract : DataContract
  15 #endif
  16     {
  17         [Fx.Tag.SecurityNote(Critical = "Holds instance of CriticalHelper which keeps state that is cached statically for serialization."
  18             + " Static fields are marked SecurityCritical or readonly to prevent data from being modified or leaked to other components in appdomain.")]
  19         [SecurityCritical]
  20         SurrogateDataContractCriticalHelper helper;
  21
  22         [Fx.Tag.SecurityNote(Critical = "Initializes SecurityCritical field 'helper'.",
  23             Safe = "Doesn't leak anything.")]
  24         [SecuritySafeCritical]
  25         internal SurrogateDataContract(Type type, ISerializationSurrogate serializationSurrogate)
  26             : base(new SurrogateDataContractCriticalHelper(type, serializationSurrogate))
  27         {
  28             helper = base.Helper as SurrogateDataContractCriticalHelper;
  29         }
  30
  31         internal ISerializationSurrogate SerializationSurrogate
  32         {
  33             [Fx.Tag.SecurityNote(Critical = "Fetches the critical serializationSurrogate property.",
  34                 Safe = "serializationSurrogate only needs to be protected for write.")]
  35             [SecuritySafeCritical]
  36             get { return helper.SerializationSurrogate; }
  37         }
  38
  39         public override void WriteXmlValue(XmlWriterDelegator xmlWriter, object obj, XmlObjectSerializerWriteContext context)
  40         {
  41             SerializationInfo serInfo = new SerializationInfo(UnderlyingType, XmlObjectSerializer.FormatterConverter, !context.UnsafeTypeForwardingEnabled);
  42             SerializationSurrogateGetObjectData(obj, serInfo, context.GetStreamingContext());
  43             context.WriteSerializationInfo(xmlWriter, UnderlyingType, serInfo);
  44         }
  45
  46         [Fx.Tag.SecurityNote(Critical = "Calls the critical methods of ISurrogateSelector", Safe = "Demands for FullTrust")]
  47         [SecuritySafeCritical]
  48         [PermissionSet(SecurityAction.Demand, Unrestricted = true)]
  49         [MethodImpl(MethodImplOptions.NoInlining)]
  50         object SerializationSurrogateSetObjectData(object obj, SerializationInfo serInfo, StreamingContext context)
  51         {
  52             return SerializationSurrogate.SetObjectData(obj, serInfo, context, null);
  53         }
  54
  55         [Fx.Tag.SecurityNote(Critical = "Calls the critical methods of IObjectReference", Safe = "Demands for FullTrust")]
  56         [SecuritySafeCritical]
  57         [PermissionSet(SecurityAction.Demand, Unrestricted = true)]
  58         [MethodImpl(MethodImplOptions.NoInlining)]
  59         internal static object GetRealObject(IObjectReference obj, StreamingContext context)
  60         {
  61             return obj.GetRealObject(context);
  62         }
  63
  64         [Fx.Tag.SecurityNote(Critical = "Calls the critical methods of FormatterServices", Safe = "Demands for FullTrust")]
  65         [SecuritySafeCritical]
  66         [PermissionSet(SecurityAction.Demand, Unrestricted = true)]
  67         [MethodImpl(MethodImplOptions.NoInlining)]
  68         object GetUninitializedObject(Type objType)
  69         {
  70             return FormatterServices.GetUninitializedObject(objType);
  71         }
  72
  73         [Fx.Tag.SecurityNote(Critical = "Calls the critical methods of ISerializationSurrogate", Safe = "Demands for FullTrust")]
  74         [SecuritySafeCritical]
  75         [PermissionSet(SecurityAction.Demand, Unrestricted = true)]
  76         [MethodImpl(MethodImplOptions.NoInlining)]
  77         void SerializationSurrogateGetObjectData(object obj, SerializationInfo serInfo, StreamingContext context)
  78         {
  79             SerializationSurrogate.GetObjectData(obj, serInfo, context);
  80         }
  81
  82         public override object ReadXmlValue(XmlReaderDelegator xmlReader, XmlObjectSerializerReadContext context)
  83         {
  84             xmlReader.Read();
  85             Type objType = UnderlyingType;
  86             object obj = objType.IsArray ? Array.CreateInstance(objType.GetElementType(), 0) : GetUninitializedObject(objType);
  87             context.AddNewObject(obj);
  88             string objectId = context.GetObjectId();
  89             SerializationInfo serInfo = context.ReadSerializationInfo(xmlReader, objType);
  90             object newObj = SerializationSurrogateSetObjectData(obj, serInfo, context.GetStreamingContext());
  91             if (newObj == null)
  92                 newObj = obj;
  93             if (newObj is IDeserializationCallback)
  94                 ((IDeserializationCallback)newObj).OnDeserialization(null);
  95             if (newObj is IObjectReference)
  96                 newObj = GetRealObject((IObjectReference)newObj, context.GetStreamingContext());
  97             context.ReplaceDeserializedObject(objectId, obj, newObj);
  98             xmlReader.ReadEndElement();
  99             return newObj;
 100         }
 101
 102         [Fx.Tag.SecurityNote(Critical = "Holds all state used for for (de)serializing with ISerializationSurrogate."
 103             + " Since it accesses data on the base type that is cached statically, we lock down access to it.")]
 104         [SecurityCritical(SecurityCriticalScope.Everything)]
 105         class SurrogateDataContractCriticalHelper : DataContract.DataContractCriticalHelper
 106         {
 107             ISerializationSurrogate serializationSurrogate;
 108
 109             internal SurrogateDataContractCriticalHelper(Type type, ISerializationSurrogate serializationSurrogate)
 110                 : base(type)
 111             {
 112                 this.serializationSurrogate = serializationSurrogate;
 113                 string name, ns;
 114                 DataContract.GetDefaultStableName(DataContract.GetClrTypeFullName(type), out name, out ns);
 115                 SetDataContractName(CreateQualifiedName(name, ns));
 116             }
 117
 118             internal ISerializationSurrogate SerializationSurrogate
 119             {
 120                 get { return serializationSurrogate; }
 121             }
 122         }
 123     }
 124 }
 125