test(gather-rules): drive the collectors through their guards

The guard functions had unit tests, but nothing proved that Registry, Wmi, Json, Xml and File actually consult them before touching the registry, WMI or disk. These drive the collectors themselves: each blocked target must come back empty, emit exactly one security_warning naming the target, and produce no rule output. Prefix-spoofing included, plus a positive case through JsonCollector so it is pinned that the guard is a gate and not a wall. Path traversal had no explicit coverage either. The sharpest case is ...\Logs\..\..\..\..\Secret.txt - the RAW string starts with an allowed prefix, so a naive StartsWith would admit it; the test pins that Path.GetFullPath canonicalizes first and the allowlist sees C:\Secret.txt. Also traversal into the C:\Users privacy block and into System32\config, both asserted under unrestrictedMode, which lifts the allowlist but never those. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
2026-10-24 12:42:38 +00:00 · 2026-07-22 10:31:49 +02:00
parent b56c774103
commit ce4d884abc
1 changed files with 124 additions and 0 deletions
@@ -266,6 +266,130 @@ namespace AutopilotMonitor.Agent.V2.Core.Tests.Monitoring.Gather
                $"expected the hung command to be killed at the timeout; took {sw.Elapsed}");
        }

+        // -------------------------------------------------------------------
+        // Every remaining collector actually calls its guard
+        //
+        // The guard functions have their own unit tests, but those prove nothing about
+        // whether a collector consults them before touching the registry, WMI or disk.
+        // These drive the collectors themselves: each blocked target must come back empty,
+        // emit exactly one security_warning naming the target, and produce no rule output.
+        // -------------------------------------------------------------------
+
+        private void AssertBlocked(Dictionary<string, object> result, string target)
+        {
+            Assert.Empty(result);
+            var warning = SingleSecurityWarning();
+            Assert.Equal(true, warning.Data["blocked"]);
+            Assert.Equal(target, warning.Data["target"]);
+            Assert.DoesNotContain(_events, e => e.EventType == "guard_test");
+        }
+
+        [Theory]
+        [InlineData(@"SAM\SAM\Domains\Account\Users")]
+        [InlineData(@"SECURITY\Policy\Secrets")]
+        [InlineData(@"HKLM\SOFTWARE\Microsoft\EnrollmentsSomethingElse")]  // prefix spoofing
+        public void RegistryCollector_OffAllowlistPath_IsBlockedBeforeTheHiveIsOpened(string target)
+            => AssertBlocked(new RegistryCollector().Execute(Rule("registry", target), Context()), target);
+
+        [Theory]
+        [InlineData("SELECT * FROM Win32_UserAccount")]
+        [InlineData("SELECT * FROM Win32_ShadowCopy")]
+        [InlineData("SELECT * FROM Win32_OperatingSystemExtra")]          // prefix spoofing
+        public void WmiCollector_OffAllowlistQuery_IsBlockedBeforeTheQueryRuns(string query)
+            => AssertBlocked(new WmiCollector().Execute(Rule("wmi", query), Context()), query);
+
+        [Fact]
+        public void JsonCollector_UserProfilePath_IsBlockedBeforeTheFileIsOpened()
+        {
+            const string target = @"C:\Users\Public\Documents\secrets.json";
+            AssertBlocked(
+                new JsonCollector().Execute(
+                    Rule("json", target, new Dictionary<string, string> { ["jsonpath"] = "$.token" }),
+                    Context()),
+                target);
+        }
+
+        [Fact]
+        public void XmlCollector_UserProfilePath_IsBlockedBeforeTheFileIsOpened()
+        {
+            const string target = @"C:\Users\Public\Documents\secrets.xml";
+            AssertBlocked(
+                new XmlCollector().Execute(
+                    Rule("xml", target, new Dictionary<string, string> { ["xpath"] = "//token" }),
+                    Context()),
+                target);
+        }
+
+        [Fact]
+        public void FileCollector_UserProfilePath_IsBlockedBeforeTheFileIsOpened()
+        {
+            const string target = @"C:\Users\Public\Documents\secrets.txt";
+            AssertBlocked(new FileCollector().Execute(Rule("file", target), Context()), target);
+        }
+
+        [Fact]
+        public void JsonCollector_AllowedPath_ReadsTheFile()
+        {
+            // Counterpart to the blocked cases: proves the guard is a gate, not a wall —
+            // the collector does reach the file once the path is admitted.
+            var path = Path.Combine(_outsideUsers, "inventory.json");
+            File.WriteAllText(path, "{ \"agent\": { \"version\": \"2.4.0\" } }");
+
+            var result = new JsonCollector().Execute(
+                Rule("json", path, new Dictionary<string, string> { ["jsonpath"] = "$.agent.version" }),
+                Context(unrestricted: true));
+
+            Assert.DoesNotContain(_events, e => e.EventType == Constants.EventTypes.SecurityWarning);
+            Assert.Contains("2.4.0", string.Join(",", result.Values));
+        }
+
+        // -------------------------------------------------------------------
+        // Path traversal
+        // -------------------------------------------------------------------
+
+        [Fact]
+        public void FilePath_TraversalOutOfAnAllowedPrefix_IsBlocked()
+        {
+            // The raw string starts with an allowed prefix, so a naive StartsWith check would
+            // admit it. Path.GetFullPath runs FIRST, so the allowlist sees C:\Secret.txt.
+            const string traversal =
+                @"C:\ProgramData\Microsoft\IntuneManagementExtension\Logs\..\..\..\..\Secret.txt";
+
+            Assert.Equal(@"C:\Secret.txt", Path.GetFullPath(traversal));
+            Assert.False(GatherRuleGuards.IsFilePathAllowed(traversal));
+        }
+
+        [Fact]
+        public void FilePath_TraversalIntoTheUsersHardBlock_StaysBlockedEvenUnrestricted()
+        {
+            // Unrestricted mode lifts the allowlist but never the C:\Users privacy block —
+            // and it must not be reachable by spelling the path with '..' either.
+            const string traversal =
+                @"C:\ProgramData\Microsoft\IntuneManagementExtension\Logs\..\..\..\..\Users\Public\ntuser.dat";
+
+            Assert.StartsWith(@"C:\Users\", Path.GetFullPath(traversal), StringComparison.OrdinalIgnoreCase);
+            Assert.False(GatherRuleGuards.IsFilePathAllowed(traversal));
+            Assert.False(GatherRuleGuards.IsFilePathAllowed(traversal, unrestrictedMode: true));
+        }
+
+        [Fact]
+        public void FilePath_TraversalIntoTheConfigHiveDirectory_StaysBlockedEvenUnrestricted()
+        {
+            const string traversal = @"C:\Windows\Logs\..\System32\config\SAM";
+
+            Assert.False(GatherRuleGuards.IsFilePathAllowed(traversal));
+            Assert.False(GatherRuleGuards.IsFilePathAllowed(traversal, unrestrictedMode: true));
+        }
+
+        [Fact]
+        public void FileCollector_TraversalTarget_IsBlockedAndReported()
+        {
+            const string traversal =
+                @"C:\ProgramData\Microsoft\IntuneManagementExtension\Logs\..\..\..\..\Users\Public\ntuser.dat";
+
+            AssertBlocked(new FileCollector().Execute(Rule("file", traversal), Context()), traversal);
+        }
+
        [Fact]
        public void LogParser_ImeLogPathOverride_StillHonoursTheUsersHardBlock()
        {