Fix System.DirectoryServices.Protocols to work on Linux (#67338)

Co-authored-by: Petteri Stenius <[email protected]>

Author: psteniusubi

src/libraries/System.DirectoryServices.Protocols/src/System/DirectoryServices/Protocols/ldap/LdapConnection.cs

@@ -634,30 +634,39 @@ private int SendRequestHelper(DirectoryRequest request, ref int messageID)
                     }
 
                     // Process the attribute.
-                    string stringValue = null;
-                    if (assertion[0] is byte[] byteArray)
+                    byte[] byteArray;
+                    if (assertion[0] is string str)
                     {
-                        if (byteArray != null && byteArray.Length != 0)
-                        {
-                            berValuePtr = new BerVal
-                            {
-                                bv_len = byteArray.Length,
-                                bv_val = Marshal.AllocHGlobal(byteArray.Length)
-                            };
-                            Marshal.Copy(byteArray, 0, berValuePtr.bv_val, byteArray.Length);
-                        }
+                        var encoder = new UTF8Encoding();
+                        byteArray = encoder.GetBytes(str);
+                    }
+                    else if (assertion[0] is Uri uri)
+                    {
+                        var encoder = new UTF8Encoding();
+                        byteArray = encoder.GetBytes(uri.ToString());
+                    }
+                    else if (assertion[0] is byte[] bytes)
+                    {
+                        byteArray = bytes;
                     }
                     else
                     {
-                        stringValue = assertion[0].ToString();
+                        throw new ArgumentException(SR.ValidValueType);
                     }
 
+                    berValuePtr = new BerVal
+                    {
+                        bv_len = byteArray.Length,
+                        bv_val = Marshal.AllocHGlobal(byteArray.Length)
+                    };
+                    Marshal.Copy(byteArray, 0, berValuePtr.bv_val, byteArray.Length);
+
                     // It is a compare request.
                     error = LdapPal.CompareDirectoryEntries(
                         _ldapHandle,
                         ((CompareRequest)request).DistinguishedName,
                         assertion.Name,
-                        stringValue,
+                        null,
                         berValuePtr,
                         serverControlArray, clientControlArray, ref messageID);
                 }

src/libraries/System.DirectoryServices.Protocols/tests/DirectoryServicesProtocolsTests.cs

@@ -1,10 +1,12 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
+using System.Collections.Generic;
 using System.Diagnostics;
 using System.DirectoryServices.Tests;
 using System.Globalization;
 using System.Net;
+using System.Text;
 using System.Threading;
 using Xunit;
 
@@ -474,6 +476,67 @@ private static void RunAsyncSearch(IAsyncResult asyncResult)
             }
         }
 
+        public static IEnumerable<object[]> TestCompareRequestTheory_TestData()
+        {
+            yield return new object[] { "input", "input", ResultCode.CompareTrue };
+            yield return new object[] { "input", Encoding.UTF8.GetBytes("input"), ResultCode.CompareTrue };
+
+            yield return new object[] { "input", "false", ResultCode.CompareFalse };
+            yield return new object[] { "input", new byte[] { 1, 2, 3, 4, 5 }, ResultCode.CompareFalse };
+
+            yield return new object[] { "http://example.com/", "http://example.com/", ResultCode.CompareTrue };
+            yield return new object[] { "http://example.com/", new Uri("http://example.com/"), ResultCode.CompareTrue };
+            yield return new object[] { "http://example.com/", Encoding.UTF8.GetBytes("http://example.com/"), ResultCode.CompareTrue };
+
+            yield return new object[] { "http://example.com/", "http://false/", ResultCode.CompareFalse };
+            yield return new object[] { "http://example.com/", new Uri("http://false/"), ResultCode.CompareFalse };
+            yield return new object[] { "http://example.com/", Encoding.UTF8.GetBytes("http://false/"), ResultCode.CompareFalse };
+        }
+
+        [ConditionalTheory(nameof(IsLdapConfigurationExist))]
+        [MemberData(nameof(TestCompareRequestTheory_TestData))]
+        public void TestCompareRequestTheory(object value, object assertion, ResultCode compareResult)
+        {
+            using (LdapConnection connection = GetConnection())
+            {
+                string ouName = "ProtocolsGroup10";
+                string rdn = "ou=" + ouName;
+
+                DeleteEntry(connection, rdn);
+                AddOrganizationalUnit(connection, rdn);
+
+                string dn = rdn + "," + LdapConfiguration.Configuration.SearchDn;
+
+                // set description to value
+                var mod = new ModifyRequest(dn, DirectoryAttributeOperation.Replace, "description", value);
+                var response = connection.SendRequest(mod);
+                Assert.Equal(ResultCode.Success, response.ResultCode);
+
+                // compare description to assertion
+                var cmp = new CompareRequest(dn, new DirectoryAttribute("description", assertion));
+                response = connection.SendRequest(cmp);
+                // assert compare result
+                Assert.Equal(compareResult, response.ResultCode);
+
+                // compare description to value
+                cmp = new CompareRequest(dn, new DirectoryAttribute("description", value));
+                response = connection.SendRequest(cmp);
+                // compare result always true
+                Assert.Equal(ResultCode.CompareTrue, response.ResultCode);
+            }
+        }
+
+        [ConditionalFact(nameof(IsLdapConfigurationExist))]
+        public void TestCompareRequest()
+        {
+            using (LdapConnection connection = GetConnection())
+            {
+                // negative case: ou=NotFound does not exist
+                var cmp = new CompareRequest("ou=NotFound," + LdapConfiguration.Configuration.SearchDn, "ou", "NotFound");
+                Assert.Throws<DirectoryOperationException>(() => connection.SendRequest(cmp));
+            }
+        }
+
         [ConditionalFact(nameof(IsActiveDirectoryServer))]
         public void TestPageRequests()
         {
@@ -586,7 +649,7 @@ public void TestSortedSearch()
                 }
             }
         }
-        
+
         private void DeleteAttribute(LdapConnection connection, string entryDn, string attributeName)
         {
             string dn = entryDn + "," + LdapConfiguration.Configuration.SearchDn;