Imported Upstream version 4.6.0.125

Former-commit-id: a2155e9bd80020e49e72e86c44da02a8ac0e57a4

mcs/class/referencesource/System.Xml/System/Xml/XmlSecureResolver.cs

@@ -0,0 +1,113 @@
+//------------------------------------------------------------------------------
+// <copyright file="XmlSecureResolver.cs" company="Microsoft">
+//     Copyright (c) Microsoft Corporation.  All rights reserved.
+// </copyright>
+// <owner current="true" primary="true">[....]</owner>
+//------------------------------------------------------------------------------
+
+namespace System.Xml {
+    using System.Net;
+    using System.Security;
+    using System.Security.Policy;
+    using System.Security.Permissions;
+    using System.Runtime.Versioning;
+
+    [PermissionSetAttribute(SecurityAction.InheritanceDemand, Name = "FullTrust")]
+    public partial class XmlSecureResolver : XmlResolver {
+        XmlResolver resolver;
+#if FEATURE_MONO_CAS
+        PermissionSet permissionSet;
+#endif
+
+#if FEATURE_MONO_CAS
+        public XmlSecureResolver(XmlResolver resolver, string securityUrl) : this(resolver, CreateEvidenceForUrl(securityUrl)) {}
+
+        public XmlSecureResolver(XmlResolver resolver, Evidence evidence) : this(resolver, SecurityManager.GetStandardSandbox(evidence)) {}
+#else
+        public XmlSecureResolver(XmlResolver resolver, string securityUrl) : this(resolver, (PermissionSet) null) {}
+
+        public XmlSecureResolver(XmlResolver resolver, Evidence evidence) : this(resolver, (PermissionSet) null) {}
+#endif
+
+        public XmlSecureResolver(XmlResolver resolver, PermissionSet permissionSet) {
+            this.resolver = resolver;
+#if FEATURE_MONO_CAS
+            this.permissionSet = permissionSet;
+#endif
+        }
+
+        public override ICredentials Credentials {
+            set { resolver.Credentials = value; }
+        }
+
+        public override object GetEntity(Uri absoluteUri, string role, Type ofObjectToReturn) {
+#if FEATURE_MONO_CAS
+            permissionSet.PermitOnly();
+#endif
+            return resolver.GetEntity(absoluteUri, role, ofObjectToReturn);
+        }
+
+        [ResourceConsumption(ResourceScope.Machine)]
+        [ResourceExposure(ResourceScope.Machine)]
+        public override Uri ResolveUri(Uri baseUri, string relativeUri) {
+            return resolver.ResolveUri(baseUri, relativeUri);
+        }
+
+        public static Evidence CreateEvidenceForUrl(string securityUrl) {
+#if FEATURE_MONO_CAS
+            Evidence evidence = new Evidence();
+            if (securityUrl != null && securityUrl.Length > 0) {
+                evidence.AddHostEvidence(new Url(securityUrl));
+                evidence.AddHostEvidence(Zone.CreateFromUrl(securityUrl));
+                Uri uri = new Uri(securityUrl, UriKind.RelativeOrAbsolute);
+                if (uri.IsAbsoluteUri && !uri.IsFile) {
+                    evidence.AddHostEvidence(Site.CreateFromUrl(securityUrl));
+                }
+
+                // Allow same directory access for UNCs (SQLBUDT 394535)
+                if (uri.IsAbsoluteUri && uri.IsUnc) {
+                    string uncDir = System.IO.Path.GetDirectoryName(uri.LocalPath);
+                    if (uncDir != null && uncDir.Length != 0) {
+                        evidence.AddHostEvidence(new UncDirectory(uncDir));
+                    }
+                }
+            }
+
+            return evidence;
+#else
+            return null;
+#endif
+        }
+
+#if FEATURE_MONO_CAS
+        [Serializable]
+        private class UncDirectory : EvidenceBase, IIdentityPermissionFactory {
+            private string uncDir;
+
+            public UncDirectory(string uncDirectory) {
+                this.uncDir = uncDirectory;
+            }
+
+            public IPermission CreateIdentityPermission(Evidence evidence) {
+                return new FileIOPermission(FileIOPermissionAccess.Read, uncDir);
+            }
+
+            public override EvidenceBase Clone()
+            {
+                return new UncDirectory(uncDir);
+            }
+
+            private SecurityElement ToXml() {
+                SecurityElement root = new SecurityElement("System.Xml.XmlSecureResolver");
+                root.AddAttribute("version", "1");
+                root.AddChild(new SecurityElement("UncDirectory", uncDir));
+                return root;
+            }
+
+            public override string ToString() {
+                return ToXml().ToString();
+            }
+        }
+#endif
+    }
+}