CSHARP-1842: Add SERVICE_REALM keeping REALM as an alias.

Author: rstam

src/MongoDB.Driver.Core/Core/Authentication/GssapiAuthenticator.cs

@@ -32,8 +32,9 @@ public sealed class GssapiAuthenticator : SaslAuthenticator
     {
         // constants
         private const string __canonicalizeHostNamePropertyName = "CANONICALIZE_HOST_NAME";
+        private const string __realmPropertyName = "REALM";
         private const string __serviceNamePropertyName = "SERVICE_NAME";
-        private const string __serviceRealmPropertyName = "REALM";
+        private const string __serviceRealmPropertyName = "SERVICE_REALM";
 
         // static properties
         /// <summary>
@@ -69,6 +70,18 @@ public static string MechanismName
             get { return "GSSAPI"; }
         }
 
+        /// <summary>
+        /// Gets the name of the realm property.
+        /// </summary>
+        /// <value>
+        /// The name of the realm property.
+        /// </value>
+        [Obsolete("Use ServiceRealmPropertyName")]
+        public static string RealmPropertyName
+        {
+            get { return __realmPropertyName; }
+        }
+
         /// <summary>
         /// Gets the name of the service name property.
         /// </summary>
@@ -143,6 +156,7 @@ private static GssapiMechanism CreateMechanism(string username, SecureString pas
                             serviceName = (string)pair.Value;
                             break;
                         case __serviceRealmPropertyName:
+                        case __realmPropertyName:
                             realm = (string)pair.Value;
                             break;
                         case __canonicalizeHostNamePropertyName: