Add LdapSessionOptions.CanonicalizeHostName property (#125454)

src/libraries/Common/src/Interop/Interop.Ldap.cs

@@ -162,7 +162,8 @@ internal enum LdapOption
         LDAP_OPT_X_TLS_NEWCTX = 0x600F, // Not Supported in Windows
         LDAP_OPT_X_SASL_REALM = 0x6101,
         LDAP_OPT_X_SASL_AUTHCID = 0x6102,
-        LDAP_OPT_X_SASL_AUTHZID = 0x6103
+        LDAP_OPT_X_SASL_AUTHZID = 0x6103,
+        LDAP_OPT_X_SASL_NOCANON = 0x610b,
     }
 
     internal enum ResultAll

src/libraries/Common/src/Interop/Linux/OpenLdap/Interop.Ldap.cs

@@ -151,7 +151,7 @@ public static partial int ldap_search(
             ref int messageNumber);
 
         [LibraryImport(Libraries.OpenLdap, EntryPoint = "ldap_set_option", SetLastError = true)]
-        public static partial int ldap_set_option_bool(ConnectionHandle ld, LdapOption option, [MarshalAs(UnmanagedType.Bool)] bool value);
+        public static partial int ldap_set_option_bool(ConnectionHandle ld, LdapOption option, IntPtr value);
 
         [LibraryImport(Libraries.OpenLdap, EntryPoint = "ldap_set_option")]
         public static partial int ldap_set_option_clientcert(ConnectionHandle ldapHandle, LdapOption option, QUERYCLIENTCERT outValue);

src/libraries/System.DirectoryServices.Protocols/ref/System.DirectoryServices.Protocols.cs

@@ -381,6 +381,9 @@ public partial class LdapSessionOptions
     {
         internal LdapSessionOptions() { }
         public bool AutoReconnect { get { throw null; } set { } }
+#if NET
+        public bool CanonicalizeHostName { get { throw null; } [System.Runtime.Versioning.UnsupportedOSPlatformAttribute("windows")] set { } }
+#endif
         public string DomainName { get { throw null; } set { } }
 #if NET
         [System.Runtime.Versioning.UnsupportedOSPlatformAttribute("windows")]

src/libraries/System.DirectoryServices.Protocols/src/System/DirectoryServices/Protocols/Interop/LdapPal.Linux.cs

@@ -98,7 +98,7 @@ internal static int SearchDirectory(ConnectionHandle ldapHandle, string dn, int
 
             return Interop.Ldap.ldap_search(ldapHandle, dn, scope, filter, attributes, attributeOnly, servercontrol, clientcontrol, searchTimeout, sizelimit, ref messageNumber);
         }
-        internal static int SetBoolOption(ConnectionHandle ld, LdapOption option, bool value) => Interop.Ldap.ldap_set_option_bool(ld, option, value);
+        internal static int SetBoolOption(ConnectionHandle ld, LdapOption option, bool value) => Interop.Ldap.ldap_set_option_bool(ld, option, value ? (IntPtr)1 : IntPtr.Zero);
 
         // This option is not supported in Linux, so it would most likely throw.
         internal static int SetClientCertOption(ConnectionHandle ldapHandle, LdapOption option, QUERYCLIENTCERT outValue) => Interop.Ldap.ldap_set_option_clientcert(ldapHandle, option, outValue);

src/libraries/System.DirectoryServices.Protocols/src/System/DirectoryServices/Protocols/ldap/LdapSessionOptions.Linux.cs

@@ -13,6 +13,13 @@ public partial class LdapSessionOptions
 
         private bool _secureSocketLayer;
 
+        public bool CanonicalizeHostName
+        {
+            get => !GetBoolValueHelper(LdapOption.LDAP_OPT_X_SASL_NOCANON);
+            [UnsupportedOSPlatform("windows")]
+            set => SetBoolValueHelper(LdapOption.LDAP_OPT_X_SASL_NOCANON, !value);
+        }
+
         /// <summary>
         /// Specifies the path of the directory containing CA certificates in the PEM format.
         /// Multiple directories may be specified by separating with a semi-colon.

src/libraries/System.DirectoryServices.Protocols/src/System/DirectoryServices/Protocols/ldap/LdapSessionOptions.Windows.cs

@@ -10,6 +10,13 @@ public partial class LdapSessionOptions
     {
         private static void PALCertFreeCRLContext(IntPtr certPtr) => Interop.Ldap.CertFreeCRLContext(certPtr);
 
+        public bool CanonicalizeHostName
+        {
+            get => true;
+            [UnsupportedOSPlatform("windows")]
+            set => throw new PlatformNotSupportedException();
+        }
+
         [UnsupportedOSPlatform("windows")]
         public string TrustedCertificatesDirectory
         {

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

@@ -785,6 +785,33 @@ public void CertificateDirectoryProperty_ThrowsPlatformNotSupportedException()
                 Assert.Throws<PlatformNotSupportedException>(() => options.TrustedCertificatesDirectory = "CertificateDirectory");
             }
         }
+
+        [Fact]
+        [PlatformSpecific(TestPlatforms.Windows)]
+        public void CanonicalizeHostName_GetReturnsTrue_SetThrowsPlatformNotSupportedException()
+        {
+            using (var connection = new LdapConnection("server"))
+            {
+                LdapSessionOptions options = connection.SessionOptions;
+                Assert.True(options.CanonicalizeHostName);
+                Assert.Throws<PlatformNotSupportedException>(() => options.CanonicalizeHostName = false);
+            }
+        }
+
+        [Fact]
+        [PlatformSpecific(TestPlatforms.Linux)]
+        public void CanonicalizeHostName_GetSet_ReturnsExpected()
+        {
+            using (var connection = new LdapConnection("server"))
+            {
+                LdapSessionOptions options = connection.SessionOptions;
+                Assert.True(options.CanonicalizeHostName);
+                options.CanonicalizeHostName = false;
+                Assert.False(options.CanonicalizeHostName);
+                options.CanonicalizeHostName = true;
+                Assert.True(options.CanonicalizeHostName);
+            }
+        }
 #endif
     }
 }