Nullable annotations for System.Security.Cryptography.Xml (#67198)

* First pass * More annotations * Rever mistaken change to test * More annotations * More annotations * More annotations * More annotations * More annotations * More annotations * More annotations * More annotations * More annotations * More annotations * More annotations * More annotations * Remove red flag comment * PR feedback * Remove 'red flag' comments * Revert unintended changes to tests * Revert unintended changes * PR feedback: remove redundant !'s from things that can never return null * Added `[MemberNotNullWhen(true, nameof(_cachedXml))]` on implementation. * Updated ref t ypes (with `dotnet msbuild /t:GenerateReferenceAssemblySource`) * Updated ref assembly * PR feedback: add `MemberNotNull` attribute on `Initialize`) * Updated ref again * Put `MemberNotNull` attribute on the getter rather than the property in the reference file. * PR feedback: remove MemberNotNullWhenAttribute from ref * PR feedback: non nullable param to match method in base class * Fix post-merge build errors * PR feedback * PR feedback from @bartonjs - add [DisallowNull] and cascade * PR feedback * PR feedback * PR feedback * Fix build again, by removing the `protected internal` property `CacheValid` * PR feedback * Added back `CacheValid` based on PR comment * Fix issues from recent rebase * Add `DisallowNull` attribute to ref file and remove it from `DefaultGenApiDocIds.txt` * PR feedback * Fix issues from recent merge * Remove some more extraneous damnit operators * Fix NRT analysis errors after prior rebase * PR feedback * PR feedback * PR feedback * PR feedback * PR feedback * CipherReference and CipherValue made to disallow null * Make Uri non-nullable on EnctrypedReference * Add AllowNull attribute on EncryptedType::KeyInfo * AllowNull on EncryptedXml::Recipient * Made baseUri nullable * DisallowNull on PropertlyElement * AllowNull on SignedInfo::CanonicalizationMethod * AllowNull on SignedXml::EncryptedXml * Fix build after recent rebase * Remove redundant damnit operator now that #71860 has been merged * PR feedback * Fix build due to change of the CanonicalXmlElement constructor * PR feedback * Remove redundant damnit operators * Fix broken tests * Fix issues after rebase * PR feedback * PR feedback
dotnet · Sep 27, 2022 · 0075639 · 0075639
1 parent bc27a6a
commit 0075639
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Showing 63 changed files with 845 additions and 795 deletions.
diff --git a/...ntime.InteropServices/gen/LibraryImportGenerator/Analyzers/ConvertToLibraryImportFixer.cs b/...ntime.InteropServices/gen/LibraryImportGenerator/Analyzers/ConvertToLibraryImportFixer.cs
@@ -74,7 +74,7 @@ public override async Task RegisterCodeFixesAsync(CodeFixContext context)
                     context.Diagnostics);
                 if (!bool.Parse(diagnostic.Properties[ConvertToLibraryImportAnalyzer.ExactSpelling]))
                 {
-                    CharSet charSet = (CharSet)Enum.Parse(typeof(CharSet), diagnostic.Properties[ConvertToLibraryImportAnalyzer.CharSet]);
+                    CharSet charSet = (CharSet)Enum.Parse(typeof(CharSet), diagnostic.Properties[ConvertToLibraryImportAnalyzer.CharSet]!);
                     // CharSet.Auto traditionally maps to either an A or W suffix
                     // depending on the default CharSet of the platform.
                     // We will offer both suffix options when CharSet.Auto is provided

diff --git a/src/libraries/System.Security.Cryptography.Xml/ref/System.Security.Cryptography.Xml.cs b/src/libraries/System.Security.Cryptography.Xml/ref/System.Security.Cryptography.Xml.cs
diff --git a/src/libraries/System.Security.Cryptography.Xml/ref/System.Security.Cryptography.Xml.csproj b/src/libraries/System.Security.Cryptography.Xml/ref/System.Security.Cryptography.Xml.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <TargetFrameworks>$(NetCoreAppCurrent);$(NetCoreAppMinimum);netstandard2.0;$(NetFrameworkMinimum)</TargetFrameworks>
-    <Nullable>disable</Nullable>
+    <Nullable>enable</Nullable>
   </PropertyGroup>
 
   <ItemGroup>

diff --git a/src/libraries/System.Security.Cryptography.Xml/src/System.Security.Cryptography.Xml.csproj b/src/libraries/System.Security.Cryptography.Xml/src/System.Security.Cryptography.Xml.csproj
@@ -2,8 +2,6 @@
   <PropertyGroup>
     <TargetFrameworks>$(NetCoreAppCurrent);$(NetCoreAppMinimum);netstandard2.0;$(NetFrameworkMinimum)</TargetFrameworks>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
-    <Nullable>disable</Nullable>
-    <NoWarn>$(NoWarn);nullable</NoWarn>
     <NoWarn>$(NoWarn);CA1850</NoWarn> <!-- CA1850 suppressed due to multitargeting -->
     <IsPackable>true</IsPackable>
     <PackageDescription>Provides classes to support the creation and validation of XML digital signatures. The classes in this namespace implement the World Wide Web Consortium Recommendation, "XML-Signature Syntax and Processing", described at http://www.w3.org/TR/xmldsig-core/.

diff --git a/...Cryptography.Xml/src/System/Security/Cryptography/Xml/AncestralNamespaceContextManager.cs b/...Cryptography.Xml/src/System/Security/Cryptography/Xml/AncestralNamespaceContextManager.cs
@@ -12,17 +12,17 @@ internal abstract class AncestralNamespaceContextManager
 
         internal NamespaceFrame GetScopeAt(int i)
         {
-            return (NamespaceFrame)_ancestorStack[i];
+            return (NamespaceFrame)_ancestorStack[i]!;
         }
 
         internal NamespaceFrame GetCurrentScope()
         {
             return GetScopeAt(_ancestorStack.Count - 1);
         }
 
-        protected XmlAttribute GetNearestRenderedNamespaceWithMatchingPrefix(string nsPrefix, out int depth)
+        protected XmlAttribute? GetNearestRenderedNamespaceWithMatchingPrefix(string nsPrefix, out int depth)
         {
-            XmlAttribute attr;
+            XmlAttribute? attr;
             depth = -1;
             for (int i = _ancestorStack.Count - 1; i >= 0; i--)
             {
@@ -35,9 +35,9 @@ protected XmlAttribute GetNearestRenderedNamespaceWithMatchingPrefix(string nsPr
             return null;
         }
 
-        protected XmlAttribute GetNearestUnrenderedNamespaceWithMatchingPrefix(string nsPrefix, out int depth)
+        protected XmlAttribute? GetNearestUnrenderedNamespaceWithMatchingPrefix(string nsPrefix, out int depth)
         {
-            XmlAttribute attr;
+            XmlAttribute? attr;
             depth = -1;
             for (int i = _ancestorStack.Count - 1; i >= 0; i--)
             {

diff --git a/...stem.Security.Cryptography.Xml/src/System/Security/Cryptography/Xml/AttributeSortOrder.cs b/...stem.Security.Cryptography.Xml/src/System/Security/Cryptography/Xml/AttributeSortOrder.cs
@@ -11,10 +11,10 @@ internal sealed class AttributeSortOrder : IComparer
     {
         internal AttributeSortOrder() { }
 
-        public int Compare(object a, object b)
+        public int Compare(object? a, object? b)
         {
-            XmlNode nodeA = a as XmlNode;
-            XmlNode nodeB = b as XmlNode;
+            XmlNode? nodeA = a as XmlNode;
+            XmlNode? nodeB = b as XmlNode;
             if ((nodeA == null) || (nodeB == null))
                 throw new ArgumentException();
             int namespaceCompare = string.CompareOrdinal(nodeA.NamespaceURI, nodeB.NamespaceURI);

diff --git a/...tography.Xml/src/System/Security/Cryptography/Xml/C14NAncestralNamespaceContextManager.cs b/...tography.Xml/src/System/Security/Cryptography/Xml/C14NAncestralNamespaceContextManager.cs
@@ -26,8 +26,8 @@ private void GetNamespaceToRender(string nsPrefix, SortedList attrListToRender,
             }
 
             int rDepth;
-            XmlAttribute local = (XmlAttribute)nsLocallyDeclared[nsPrefix];
-            XmlAttribute rAncestral = GetNearestRenderedNamespaceWithMatchingPrefix(nsPrefix, out rDepth);
+            XmlAttribute? local = (XmlAttribute?)nsLocallyDeclared[nsPrefix];
+            XmlAttribute? rAncestral = GetNearestRenderedNamespaceWithMatchingPrefix(nsPrefix, out rDepth);
             if (local != null)
             {
                 if (Utils.IsNonRedundantNamespaceDecl(local, rAncestral))
@@ -42,7 +42,7 @@ private void GetNamespaceToRender(string nsPrefix, SortedList attrListToRender,
             else
             {
                 int uDepth;
-                XmlAttribute uAncestral = GetNearestUnrenderedNamespaceWithMatchingPrefix(nsPrefix, out uDepth);
+                XmlAttribute? uAncestral = GetNearestUnrenderedNamespaceWithMatchingPrefix(nsPrefix, out uDepth);
                 if (uAncestral != null && uDepth > rDepth && Utils.IsNonRedundantNamespaceDecl(uAncestral, rAncestral))
                 {
                     if (Utils.IsXmlNamespaceNode(uAncestral))
@@ -55,14 +55,14 @@ private void GetNamespaceToRender(string nsPrefix, SortedList attrListToRender,
 
         internal override void GetNamespacesToRender(XmlElement element, SortedList attrListToRender, SortedList nsListToRender, Hashtable nsLocallyDeclared)
         {
-            XmlAttribute attrib;
+            XmlAttribute? attrib;
             object[] attrs = new object[nsLocallyDeclared.Count];
             nsLocallyDeclared.Values.CopyTo(attrs, 0);
             foreach (object a in attrs)
             {
                 attrib = (XmlAttribute)a;
                 int rDepth;
-                XmlAttribute rAncestral = GetNearestRenderedNamespaceWithMatchingPrefix(Utils.GetNamespacePrefix(attrib), out rDepth);
+                XmlAttribute? rAncestral = GetNearestRenderedNamespaceWithMatchingPrefix(Utils.GetNamespacePrefix(attrib), out rDepth);
                 if (Utils.IsNonRedundantNamespaceDecl(attrib, rAncestral))
                 {
                     nsLocallyDeclared.Remove(Utils.GetNamespacePrefix(attrib));

diff --git a/...ies/System.Security.Cryptography.Xml/src/System/Security/Cryptography/Xml/CanonicalXml.cs b/...ies/System.Security.Cryptography.Xml/src/System/Security/Cryptography/Xml/CanonicalXml.cs
@@ -17,7 +17,7 @@ internal sealed class CanonicalXml
         // private static string defaultXPathWithComments = "(//. | //@* | //namespace::*)";
         // private static string defaultXPathWithComments = "(//. | //@* | //namespace::*)";
 
-        internal CanonicalXml(Stream inputStream, bool includeComments, XmlResolver resolver, string strBaseUri)
+        internal CanonicalXml(Stream inputStream, bool includeComments, XmlResolver? resolver, string strBaseUri)
         {
             if (inputStream is null)
             {
@@ -30,8 +30,8 @@ internal CanonicalXml(Stream inputStream, bool includeComments, XmlResolver reso
             _ancMgr = new C14NAncestralNamespaceContextManager();
         }
 
-        internal CanonicalXml(XmlDocument document, XmlResolver resolver) : this(document, resolver, false) { }
-        internal CanonicalXml(XmlDocument document, XmlResolver resolver, bool includeComments)
+        internal CanonicalXml(XmlDocument document, XmlResolver? resolver) : this(document, resolver, false) { }
+        internal CanonicalXml(XmlDocument document, XmlResolver? resolver, bool includeComments)
         {
             if (document is null)
             {
@@ -44,14 +44,14 @@ internal CanonicalXml(XmlDocument document, XmlResolver resolver, bool includeCo
             _ancMgr = new C14NAncestralNamespaceContextManager();
         }
 
-        internal CanonicalXml(XmlNodeList nodeList, XmlResolver resolver, bool includeComments)
+        internal CanonicalXml(XmlNodeList nodeList, XmlResolver? resolver, bool includeComments)
         {
             if (nodeList is null)
             {
                 throw new ArgumentNullException(nameof(nodeList));
             }
 
-            XmlDocument doc = Utils.GetOwnerDocument(nodeList);
+            XmlDocument? doc = Utils.GetOwnerDocument(nodeList);
             if (doc == null)
                 throw new ArgumentException(nameof(nodeList));
 
@@ -79,8 +79,8 @@ private static void MarkInclusionStateForNodes(XmlNodeList nodeList, XmlDocument
 
             do
             {
-                XmlNode currentNode = (XmlNode)elementList[index];
-                XmlNode currentNodeCanonical = (XmlNode)elementListCanonical[index];
+                XmlNode currentNode = (XmlNode)elementList[index]!;
+                XmlNode currentNodeCanonical = (XmlNode)elementListCanonical[index]!;
                 XmlNodeList childNodes = currentNode.ChildNodes;
                 XmlNodeList childNodesCanonical = currentNodeCanonical.ChildNodes;
                 for (int i = 0; i < childNodes.Count; i++)
@@ -90,17 +90,17 @@ private static void MarkInclusionStateForNodes(XmlNodeList nodeList, XmlDocument
 
                     if (Utils.NodeInList(childNodes[i], nodeList))
                     {
-                        MarkNodeAsIncluded(childNodesCanonical[i]);
+                        MarkNodeAsIncluded(childNodesCanonical[i]!);
                     }
 
-                    XmlAttributeCollection attribNodes = childNodes[i].Attributes;
+                    XmlAttributeCollection? attribNodes = childNodes[i]!.Attributes;
                     if (attribNodes != null)
                     {
                         for (int j = 0; j < attribNodes.Count; j++)
                         {
                             if (Utils.NodeInList(attribNodes[j], nodeList))
                             {
-                                MarkNodeAsIncluded(childNodesCanonical[i].Attributes.Item(j));
+                                MarkNodeAsIncluded(childNodesCanonical[i]!.Attributes!.Item(j)!);
                             }
                         }
                     }
@@ -121,7 +121,7 @@ internal byte[] GetDigestedBytes(HashAlgorithm hash)
         {
             _c14nDoc.WriteHash(hash, DocPosition.BeforeRootElement, _ancMgr);
             hash.TransformFinalBlock(Array.Empty<byte>(), 0, 0);
-            byte[] res = (byte[])hash.Hash.Clone();
+            byte[] res = (byte[])hash.Hash!.Clone();
             // reinitialize the hash so it is still usable after the call
             hash.Initialize();
             return res;

diff --git a/...m.Security.Cryptography.Xml/src/System/Security/Cryptography/Xml/CanonicalXmlAttribute.cs b/...m.Security.Cryptography.Xml/src/System/Security/Cryptography/Xml/CanonicalXmlAttribute.cs
@@ -11,7 +11,7 @@ internal sealed class CanonicalXmlAttribute : XmlAttribute, ICanonicalizableNode
     {
         private bool _isInNodeSet;
 
-        public CanonicalXmlAttribute(string prefix, string localName, string namespaceURI, XmlDocument doc, bool defaultNodeSetInclusionState)
+        public CanonicalXmlAttribute(string? prefix, string localName, string? namespaceURI, XmlDocument doc, bool defaultNodeSetInclusionState)
             : base(prefix, localName, namespaceURI, doc)
         {
             IsInNodeSet = defaultNodeSetInclusionState;

diff --git a/...ecurity.Cryptography.Xml/src/System/Security/Cryptography/Xml/CanonicalXmlCDataSection.cs b/...ecurity.Cryptography.Xml/src/System/Security/Cryptography/Xml/CanonicalXmlCDataSection.cs
@@ -10,7 +10,7 @@ namespace System.Security.Cryptography.Xml
     internal sealed class CanonicalXmlCDataSection : XmlCDataSection, ICanonicalizableNode
     {
         private bool _isInNodeSet;
-        public CanonicalXmlCDataSection(string data, XmlDocument doc, bool defaultNodeSetInclusionState) : base(data, doc)
+        public CanonicalXmlCDataSection(string? data, XmlDocument doc, bool defaultNodeSetInclusionState) : base(data, doc)
         {
             _isInNodeSet = defaultNodeSetInclusionState;
         }

diff --git a/...tem.Security.Cryptography.Xml/src/System/Security/Cryptography/Xml/CanonicalXmlComment.cs b/...tem.Security.Cryptography.Xml/src/System/Security/Cryptography/Xml/CanonicalXmlComment.cs
@@ -12,7 +12,7 @@ internal sealed class CanonicalXmlComment : XmlComment, ICanonicalizableNode
         private bool _isInNodeSet;
         private readonly bool _includeComments;
 
-        public CanonicalXmlComment(string comment, XmlDocument doc, bool defaultNodeSetInclusionState, bool includeComments)
+        public CanonicalXmlComment(string? comment, XmlDocument doc, bool defaultNodeSetInclusionState, bool includeComments)
             : base(comment, doc)
         {
             _isInNodeSet = defaultNodeSetInclusionState;
@@ -55,7 +55,7 @@ public void WriteHash(HashAlgorithm hash, DocPosition docPos, AncestralNamespace
                 hash.TransformBlock(rgbData, 0, rgbData.Length, rgbData, 0);
             rgbData = utf8.GetBytes("<!--");
             hash.TransformBlock(rgbData, 0, rgbData.Length, rgbData, 0);
-            rgbData = utf8.GetBytes(Value);
+            rgbData = utf8.GetBytes(Value!);
             hash.TransformBlock(rgbData, 0, rgbData.Length, rgbData, 0);
             rgbData = utf8.GetBytes("-->");
             hash.TransformBlock(rgbData, 0, rgbData.Length, rgbData, 0);

diff --git a/...em.Security.Cryptography.Xml/src/System/Security/Cryptography/Xml/CanonicalXmlDocument.cs b/...em.Security.Cryptography.Xml/src/System/Security/Cryptography/Xml/CanonicalXmlDocument.cs
@@ -61,42 +61,42 @@ public void WriteHash(HashAlgorithm hash, DocPosition docPos, AncestralNamespace
             }
         }
 
-        public override XmlElement CreateElement(string prefix, string localName, string namespaceURI)
+        public override XmlElement CreateElement(string? prefix, string localName, string? namespaceURI)
         {
             return new CanonicalXmlElement(prefix, localName, namespaceURI, this, _defaultNodeSetInclusionState);
         }
 
-        public override XmlAttribute CreateAttribute(string prefix, string localName, string namespaceURI)
+        public override XmlAttribute CreateAttribute(string? prefix, string localName, string? namespaceURI)
         {
             return new CanonicalXmlAttribute(prefix, localName, namespaceURI, this, _defaultNodeSetInclusionState);
         }
 
-        protected override XmlAttribute CreateDefaultAttribute(string prefix, string localName, string namespaceURI)
+        protected override XmlAttribute CreateDefaultAttribute(string? prefix, string localName, string? namespaceURI)
         {
             return new CanonicalXmlAttribute(prefix, localName, namespaceURI, this, _defaultNodeSetInclusionState);
         }
 
-        public override XmlText CreateTextNode(string text)
+        public override XmlText CreateTextNode(string? text)
         {
             return new CanonicalXmlText(text, this, _defaultNodeSetInclusionState);
         }
 
-        public override XmlWhitespace CreateWhitespace(string prefix)
+        public override XmlWhitespace CreateWhitespace(string? prefix)
         {
             return new CanonicalXmlWhitespace(prefix, this, _defaultNodeSetInclusionState);
         }
 
-        public override XmlSignificantWhitespace CreateSignificantWhitespace(string text)
+        public override XmlSignificantWhitespace CreateSignificantWhitespace(string? text)
         {
             return new CanonicalXmlSignificantWhitespace(text, this, _defaultNodeSetInclusionState);
         }
 
-        public override XmlProcessingInstruction CreateProcessingInstruction(string target, string data)
+        public override XmlProcessingInstruction CreateProcessingInstruction(string target, string? data)
         {
-            return new CanonicalXmlProcessingInstruction(target, data, this, _defaultNodeSetInclusionState);
+            return new CanonicalXmlProcessingInstruction(target, data!, this, _defaultNodeSetInclusionState);
         }
 
-        public override XmlComment CreateComment(string data)
+        public override XmlComment CreateComment(string? data)
         {
             return new CanonicalXmlComment(data, this, _defaultNodeSetInclusionState, _includeComments);
         }
@@ -106,7 +106,7 @@ public override XmlEntityReference CreateEntityReference(string name)
             return new CanonicalXmlEntityReference(name, this, _defaultNodeSetInclusionState);
         }
 
-        public override XmlCDataSection CreateCDataSection(string data)
+        public override XmlCDataSection CreateCDataSection(string? data)
         {
             return new CanonicalXmlCDataSection(data, this, _defaultNodeSetInclusionState);
         }

diff --git a/...tem.Security.Cryptography.Xml/src/System/Security/Cryptography/Xml/CanonicalXmlElement.cs b/...tem.Security.Cryptography.Xml/src/System/Security/Cryptography/Xml/CanonicalXmlElement.cs
@@ -12,8 +12,8 @@ internal sealed class CanonicalXmlElement : XmlElement, ICanonicalizableNode
     {
         private bool _isInNodeSet;
 
-        public CanonicalXmlElement(string prefix, string localName, string namespaceURI, XmlDocument doc, bool defaultNodeSetInclusionState)
-            : base(prefix, localName, namespaceURI, doc)
+        public CanonicalXmlElement(string? prefix, string localName, string? namespaceURI, XmlDocument doc, bool defaultNodeSetInclusionState)
+            : base(prefix!, localName, namespaceURI, doc)
         {
             _isInNodeSet = defaultNodeSetInclusionState;
         }
@@ -30,7 +30,7 @@ public void Write(StringBuilder strBuilder, DocPosition docPos, AncestralNamespa
             SortedList nsListToRender = new SortedList(new NamespaceSortOrder());
             SortedList attrListToRender = new SortedList(new AttributeSortOrder());
 
-            XmlAttributeCollection attrList = Attributes;
+            XmlAttributeCollection? attrList = Attributes;
             if (attrList != null)
             {
                 foreach (XmlAttribute attr in attrList)
@@ -68,11 +68,11 @@ public void Write(StringBuilder strBuilder, DocPosition docPos, AncestralNamespa
                 strBuilder.Append('<').Append(Name);
                 foreach (object attr in nsListToRender.GetKeyList())
                 {
-                    (attr as CanonicalXmlAttribute).Write(strBuilder, docPos, anc);
+                    (attr as CanonicalXmlAttribute)!.Write(strBuilder, docPos, anc);
                 }
                 foreach (object attr in attrListToRender.GetKeyList())
                 {
-                    (attr as CanonicalXmlAttribute).Write(strBuilder, docPos, anc);
+                    (attr as CanonicalXmlAttribute)!.Write(strBuilder, docPos, anc);
                 }
                 strBuilder.Append('>');
             }
@@ -141,11 +141,11 @@ public void WriteHash(HashAlgorithm hash, DocPosition docPos, AncestralNamespace
                 hash.TransformBlock(rgbData, 0, rgbData.Length, rgbData, 0);
                 foreach (object attr in nsListToRender.GetKeyList())
                 {
-                    (attr as CanonicalXmlAttribute).WriteHash(hash, docPos, anc);
+                    (attr as CanonicalXmlAttribute)!.WriteHash(hash, docPos, anc);
                 }
                 foreach (object attr in attrListToRender.GetKeyList())
                 {
-                    (attr as CanonicalXmlAttribute).WriteHash(hash, docPos, anc);
+                    (attr as CanonicalXmlAttribute)!.WriteHash(hash, docPos, anc);
                 }
                 rgbData = utf8.GetBytes(">");
                 hash.TransformBlock(rgbData, 0, rgbData.Length, rgbData, 0);

diff --git a/...em.Security.Cryptography.Xml/src/System/Security/Cryptography/Xml/CanonicalXmlNodeList.cs b/...em.Security.Cryptography.Xml/src/System/Security/Cryptography/Xml/CanonicalXmlNodeList.cs
@@ -17,7 +17,7 @@ internal CanonicalXmlNodeList()
 
         public override XmlNode Item(int index)
         {
-            return (XmlNode)_nodeArray[index];
+            return (XmlNode)_nodeArray[index]!;
         }
 
         public override IEnumerator GetEnumerator()
@@ -31,7 +31,7 @@ public override int Count
         }
 
         // IList methods
-        public int Add(object value)
+        public int Add(object? value)
         {
             if (!(value is XmlNode))
                 throw new ArgumentException(SR.Cryptography_Xml_IncorrectObjectType, "node");
@@ -43,24 +43,24 @@ public void Clear()
             _nodeArray.Clear();
         }
 
-        public bool Contains(object value)
+        public bool Contains(object? value)
         {
             return _nodeArray.Contains(value);
         }
 
-        public int IndexOf(object value)
+        public int IndexOf(object? value)
         {
             return _nodeArray.IndexOf(value);
         }
 
-        public void Insert(int index, object value)
+        public void Insert(int index, object? value)
         {
             if (!(value is XmlNode))
                 throw new ArgumentException(SR.Cryptography_Xml_IncorrectObjectType, nameof(value));
             _nodeArray.Insert(index, value);
         }
 
-        public void Remove(object value)
+        public void Remove(object? value)
         {
             _nodeArray.Remove(value);
         }
@@ -80,7 +80,7 @@ public bool IsReadOnly
             get { return _nodeArray.IsReadOnly; }
         }
 
-        object IList.this[int index]
+        object? IList.this[int index]
         {
             get { return _nodeArray[index]; }
             set

diff --git a/...ryptography.Xml/src/System/Security/Cryptography/Xml/CanonicalXmlSignificantWhitespace.cs b/...ryptography.Xml/src/System/Security/Cryptography/Xml/CanonicalXmlSignificantWhitespace.cs
@@ -11,7 +11,7 @@ internal sealed class CanonicalXmlSignificantWhitespace : XmlSignificantWhitespa
     {
         private bool _isInNodeSet;
 
-        public CanonicalXmlSignificantWhitespace(string strData, XmlDocument doc, bool defaultNodeSetInclusionState)
+        public CanonicalXmlSignificantWhitespace(string? strData, XmlDocument doc, bool defaultNodeSetInclusionState)
             : base(strData, doc)
         {
             _isInNodeSet = defaultNodeSetInclusionState;