bastion 0.53.2

client-go/sysservice_programfiles_static_test.go

@@ -0,0 +1,76 @@
+package main
+
+// `service install` on Windows refuses a program outside Program Files
+// (windowsServiceBinaryOK), because whoever can replace the service's file
+// runs code as LocalSystem. Where Program Files IS must come from HKLM, which
+// only an administrator can change, and never from %ProgramFiles%: an elevated
+// process's environment carries the elevating account's own variables. That
+// code is behind //go:build windows, so the suite reads it instead of running it.
+
+import (
+	"go/ast"
+	"go/token"
+	"strconv"
+	"testing"
+)
+
+func TestTheServiceBinaryCheckTakesProgramFilesFromHKLM(t *testing.T) {
+	p := parseSources(t)
+	f, ok := p.files["sysservice_windows.go"]
+	if !ok {
+		t.Fatal("sysservice_windows.go is not in the package")
+	}
+	var fromEnv []string
+	readsHKLM := false
+	installUsesIt := false
+	ast.Inspect(f, func(n ast.Node) bool {
+		switch x := n.(type) {
+		case *ast.CallExpr:
+			if sel, ok := x.Fun.(*ast.SelectorExpr); ok {
+				if id, ok := sel.X.(*ast.Ident); ok && id.Name == "os" && (sel.Sel.Name == "Getenv" || sel.Sel.Name == "LookupEnv") && len(x.Args) == 1 {
+					if lit, ok := x.Args[0].(*ast.BasicLit); ok && lit.Kind == token.STRING {
+						if v, _ := strconv.Unquote(lit.Value); v == "ProgramFiles" {
+							fromEnv = append(fromEnv, p.fset.Position(x.Pos()).String())
+						}
+					}
+				}
+			}
+		case *ast.FuncDecl:
+			switch x.Name.Name {
+			case "programFilesDir":
+				lm, name := false, false
+				ast.Inspect(x, func(m ast.Node) bool {
+					if sel, ok := m.(*ast.SelectorExpr); ok && sel.Sel.Name == "LOCAL_MACHINE" {
+						lm = true
+					}
+					if lit, ok := m.(*ast.BasicLit); ok && lit.Kind == token.STRING {
+						if v, _ := strconv.Unquote(lit.Value); v == "ProgramFilesDir" {
+							name = true
+						}
+					}
+					return true
+				})
+				readsHKLM = lm && name
+			case "installSystemService":
+				ast.Inspect(x, func(m ast.Node) bool {
+					if c, ok := m.(*ast.CallExpr); ok {
+						if id, ok := c.Fun.(*ast.Ident); ok && id.Name == "programFilesDir" {
+							installUsesIt = true
+						}
+					}
+					return true
+				})
+			}
+		}
+		return true
+	})
+	if len(fromEnv) > 0 {
+		t.Errorf("Program Files is read from the environment, which the elevating account can set: %v", fromEnv)
+	}
+	if !readsHKLM {
+		t.Error("programFilesDir must read ProgramFilesDir under HKLM (registry.LOCAL_MACHINE)")
+	}
+	if !installUsesIt {
+		t.Error("installSystemService must take Program Files from programFilesDir")
+	}
+}