Added recursion limits to AbstractReader.cs

protos/extest/unittest_extras_xmltest.proto

-// Additional options required for C# generation. File from copyright
-// line onwards is as per original distribution.
-import "google/protobuf/csharp_options.proto";
-option (google.protobuf.csharp_file_options).namespace = "Google.ProtocolBuffers.TestProtos";
-option (google.protobuf.csharp_file_options).umbrella_classname = "UnitTestXmlSerializerTestProtoFile";
-
-package protobuf_unittest_extra;
-
-option optimize_for = SPEED;
-
-enum EnumOptions {
-    ONE = 0;
-    TWO = 1;
-    THREE = 2;
-}
-
-message TestXmlChild
-{
-    repeated EnumOptions options = 3;
-    optional bytes binary = 4;
-}
-
-message TestXmlNoFields {
-}
-
-message TestXmlMessage {
-
-    optional int64 number = 6;
-    repeated int32 numbers = 2;
-    optional string text = 3;
-    repeated string textlines = 700;
-    optional bool valid = 5;
-    
-    optional TestXmlChild child = 1;
-    repeated group Children = 401 
-    {
-        repeated EnumOptions options = 3;
+// Additional options required for C# generation. File from copyright
+// line onwards is as per original distribution.
+import "google/protobuf/csharp_options.proto";
+option (google.protobuf.csharp_file_options).namespace = "Google.ProtocolBuffers.TestProtos";
+option (google.protobuf.csharp_file_options).umbrella_classname = "UnitTestXmlSerializerTestProtoFile";
+
+package protobuf_unittest_extra;
+
+option optimize_for = SPEED;
+
+enum EnumOptions {
+    ONE = 0;
+    TWO = 1;
+    THREE = 2;
+}
+
+message TestXmlChild
+{
+    repeated EnumOptions options = 3;
+    optional bytes binary = 4;
+}
+
+message TestXmlNoFields {
+}
+
+message TestXmlRescursive {
+    optional TestXmlRescursive child = 1;
+}
+
+message TestXmlMessage {
+
+    optional int64 number = 6;
+    repeated int32 numbers = 2;
+    optional string text = 3;
+    repeated string textlines = 700;
+    optional bool valid = 5;
+    
+    optional TestXmlChild child = 1;
+    repeated group Children = 401 
+    {
+        repeated EnumOptions options = 3;
         optional bytes binary = 4;
     }
-
-    extensions 100 to 199;
-}
-
-message  TestXmlExtension {
-  required int32 number = 1;
-}
-  
-extend TestXmlMessage {
-  optional EnumOptions extension_enum = 101;
-  optional string extension_text = 102;
-  repeated int32 extension_number = 103 [packed = true];
-  optional TestXmlExtension extension_message = 199;
-}
+
+    extensions 100 to 199;
+}
+
+message  TestXmlExtension {
+  required int32 number = 1;
+}
+  
+extend TestXmlMessage {
+  optional EnumOptions extension_enum = 101;
+  optional string extension_text = 102;
+  repeated int32 extension_number = 103 [packed = true];
+  optional TestXmlExtension extension_message = 199;
+}

src/ProtocolBuffers.Test/TestWriterFormatJson.cs

 using System;
 using System.IO;
+using System.Text;
 using Google.ProtocolBuffers.Serialization;
 using NUnit.Framework;
 using Google.ProtocolBuffers.TestProtos;
@@ -336,6 +337,14 @@ namespace Google.ProtocolBuffers
             Assert.AreEqual(3, ordinal);
             Assert.AreEqual(3, builder.TextlinesCount);
         }
+        [Test,ExpectedException(typeof(InvalidProtocolBufferException))]
+        public void TestRecursiveLimit()
+        {
+            StringBuilder sb = new StringBuilder(8192);
+            for (int i = 0; i < 80; i++)
+                sb.Append("{\"child\":");
+            TestXmlRescursive msg = TestXmlRescursive.ParseFromJson(sb.ToString());
+        }
         [Test, ExpectedException(typeof(FormatException))]
         public void FailWithEmptyText()
         {

src/ProtocolBuffers.Test/TestWriterFormatXml.cs

@@ -324,5 +324,13 @@ namespace Google.ProtocolBuffers
             TestXmlMessage copy = rdr.Merge(TestXmlMessage.CreateBuilder(), registry).Build();
             Assert.AreEqual(message, copy);
         }
+        [Test, ExpectedException(typeof(InvalidProtocolBufferException))]
+        public void TestRecursiveLimit()
+        {
+            StringBuilder sb = new StringBuilder(8192);
+            for (int i = 0; i < 80; i++)
+                sb.Append("<child>");
+            TestXmlRescursive msg = TestXmlRescursive.ParseFromXml("child", XmlReader.Create(new StringReader(sb.ToString())));
+        }
     }
 }

src/ProtocolBuffers/Serialization/AbstractReader.cs

@@ -12,6 +12,9 @@ namespace Google.ProtocolBuffers.Serialization
     /// </summary>
     public abstract class AbstractReader : ICodedInputStream
     {
+        const int MaxDepth = CodedInputStream.DefaultRecursionLimit;
+        protected int _depth;
+
         /// <summary>
         /// Merges the contents of stream into the provided message builder
         /// </summary>
@@ -330,13 +333,23 @@ namespace Google.ProtocolBuffers.Serialization
         { return Read(ref value); }
 
         void ICodedInputStream.ReadGroup(int fieldNumber, IBuilderLite builder, ExtensionRegistry extensionRegistry)
-        { ReadGroup(builder, extensionRegistry); }
+        {
+            if (_depth++ > MaxDepth)
+                throw InvalidProtocolBufferException.RecursionLimitExceeded();
+            ReadGroup(builder, extensionRegistry);
+            _depth--;
+        }
 
         void ICodedInputStream.ReadUnknownGroup(int fieldNumber, IBuilderLite builder)
         { throw new NotSupportedException(); }
 
         void ICodedInputStream.ReadMessage(IBuilderLite builder, ExtensionRegistry extensionRegistry)
-        { ReadMessage(builder, extensionRegistry); }
+        {
+            if (_depth++ > MaxDepth)
+                throw InvalidProtocolBufferException.RecursionLimitExceeded(); 
+            ReadMessage(builder, extensionRegistry);
+            _depth--;
+        }
 
         bool ICodedInputStream.ReadBytes(ref ByteString value)
         { return Read(ref value); }
@@ -439,10 +452,20 @@ namespace Google.ProtocolBuffers.Serialization
         }
 
         void ICodedInputStream.ReadMessageArray<T>(uint fieldTag, string fieldName, ICollection<T> list, T messageType, ExtensionRegistry registry)
-        { ReadMessageArray(fieldName, list, messageType, registry); }
+        {
+            if (_depth++ > MaxDepth)
+                throw InvalidProtocolBufferException.RecursionLimitExceeded(); 
+            ReadMessageArray(fieldName, list, messageType, registry);
+            _depth--;
+        }
 
         void ICodedInputStream.ReadGroupArray<T>(uint fieldTag, string fieldName, ICollection<T> list, T messageType, ExtensionRegistry registry)
-        { ReadGroupArray(fieldName, list, messageType, registry); }
+        {
+            if (_depth++ > MaxDepth)
+                throw InvalidProtocolBufferException.RecursionLimitExceeded();
+            ReadGroupArray(fieldName, list, messageType, registry);
+            _depth--;
+        }
 
         bool ICodedInputStream.ReadPrimitiveField(FieldType fieldType, ref object value)
         { return ReadField(fieldType, ref value); }

src/ProtocolBuffers/Serialization/DictionaryWriter.cs

@@ -15,7 +15,7 @@ namespace Google.ProtocolBuffers.Serialization
         /// Constructs a writer using a new dictionary
         /// </summary>
         public DictionaryWriter()
-            : this(new Dictionary<string,object>())
+            : this(new Dictionary<string,object>(StringComparer.Ordinal))
         { }
 
         /// <summary>
@@ -27,6 +27,14 @@ namespace Google.ProtocolBuffers.Serialization
             _output = output;
         }
 
+        /// <summary>
+        /// Creates the dictionary instance for a child message.
+        /// </summary>
+        protected virtual DictionaryWriter Create()
+        {
+            return new DictionaryWriter();
+        }
+
         /// <summary>
         /// Accesses the dictionary that is backing this writer
         /// </summary>
@@ -119,7 +127,7 @@ namespace Google.ProtocolBuffers.Serialization
         /// </summary>
         protected override void WriteMessageOrGroup(string field, IMessageLite message)
         {
-            DictionaryWriter writer = new DictionaryWriter();
+            DictionaryWriter writer = Create();
             writer.WriteMessage(message);
 
             _output[field] = writer.ToDictionary();
@@ -146,7 +154,7 @@ namespace Google.ProtocolBuffers.Serialization
                     case FieldType.Group:
                     case FieldType.Message:
                         {
-                            DictionaryWriter writer = new DictionaryWriter();
+                            DictionaryWriter writer = Create();
                             writer.WriteMessage((IMessageLite)o);
                             objects.Add(writer.ToDictionary());
                         }

src/ProtocolBuffers/Serialization/XmlFormatReader.cs

@@ -72,7 +72,11 @@ namespace Google.ProtocolBuffers.Serialization
 
         private XmlFormatReader CloneWith(XmlReader rdr)
         {
-            return new XmlFormatReader(rdr).SetOptions(Options);
+            XmlFormatReader copy = new XmlFormatReader(rdr).SetOptions(Options);
+            copy._rootElementName = _rootElementName;
+            copy._depth = _depth;
+            return copy;
+
         }
         private void NextElement()
         {