Add NTLMv1 flag on GPO

src/CommonLib/OutputTypes/GPO.cs

@@ -2,5 +2,6 @@
 {
     public class GPO : OutputBase
     {
+        public bool NTLMv1Enabled { get; set; }
     }
 }

src/CommonLib/Processors/GPOLmCompatibilityLevelProcessor.cs

@@ -0,0 +1,88 @@
+using System;
+using System.DirectoryServices.Protocols;
+using System.IO;
+using System.Linq;
+using System.Text.RegularExpressions;
+using System.Threading.Tasks;
+using Microsoft.Extensions.Logging;
+using SharpHoundCommonLib.LDAPQueries;
+
+namespace SharpHoundCommonLib.Processors
+{
+    public class GPOLmCompatibilityLevelProcessor
+    {
+        private static readonly Regex NTLMv1Regex = new Regex(@"\\LmCompatibilityLevel *= *\d+ *, *(\d)", RegexOptions.Compiled | RegexOptions.Singleline | RegexOptions.IgnoreCase);
+
+        private readonly ILogger _log;
+
+        private readonly ILDAPUtils _utils;
+
+        public GPOLmCompatibilityLevelProcessor(ILDAPUtils utils, ILogger log = null)
+        {
+            _utils = utils;
+            _log = log ?? Logging.LogProvider.CreateLogger("GPOLmCompatProc");
+        }
+
+        public Task<Boolean> ReadGPOLmCompatibilityLevel(ISearchResultEntry entry)
+        {
+            var dn = entry.DistinguishedName;
+            return ReadGPOLmCompatibilityLevel(dn);
+        }
+
+        public async Task<Boolean> ReadGPOLmCompatibilityLevel(string gpDn)
+        {
+            var opts = new LDAPQueryOptions
+            {
+                Filter = new LDAPFilter().AddAllObjects().GetFilter(),
+                Scope = SearchScope.Base,
+                Properties = CommonProperties.GPCFileSysPath,
+                AdsPath = gpDn
+            };
+            var filePath = _utils.QueryLDAP(opts).FirstOrDefault()?
+                .GetProperty(LDAPProperties.GPCFileSYSPath);
+            if (filePath == null)
+            {
+                _log.LogWarning("Unable to process {} for NTLMv1 flag", gpDn);
+                return false;
+            }
+
+            return await ProcessGPOTemplateFile(filePath);
+        }
+
+        /// <summary>
+        ///     Parses a GPO GptTmpl.inf file and grep lmcompatibilitylevel value
+        /// </summary>
+        /// <param name="basePath"></param>
+        /// <returns>
+        ///     lmcompatibilitylevel < 3
+        /// </returns>
+        internal async Task<Boolean> ProcessGPOTemplateFile(string basePath)
+        {
+            var templatePath = Path.Combine(basePath, "MACHINE", "Microsoft", "Windows NT", "SecEdit", "GptTmpl.inf");
+
+            if (!File.Exists(templatePath))
+                return false;
+
+            FileStream fs;
+            try
+            {
+                fs = new FileStream(templatePath, FileMode.Open, FileAccess.Read);
+            }
+            catch
+            {
+                return false;
+            }
+
+            using var reader = new StreamReader(fs);
+            var content = await reader.ReadToEndAsync();
+            var ntlmv1Match = NTLMv1Regex.Match(content);
+
+            if (!ntlmv1Match.Success)
+                return false;
+
+            //We've got a match! Lets figure out whats going on
+            var ntlmv1Text = int.Parse(ntlmv1Match.Groups[1].Value);
+            return ntlmv1Text < 3;
+        }
+    }
+}