6 files changed, 128 insertions, 5 deletions
diff --git a/include/winapi/sid.hpp b/include/winapi/sid.hpp
new file mode 100644
index 0000000..f418b89
--- /dev/null
+++ b/include/winapi/sid.hpp
@@ -0,0 +1,43 @@
+// Copyright (c) 2020 Egor Tensin <Egor.Tensin@gmail.com>
+// This file is part of the "winapi-common" project.
+// For details, see https://github.com/egor-tensin/winapi-common.
+// Distributed under the MIT License.
+
+#pragma once
+
+#include "buffer.hpp"
+
+#include <boost/config.hpp>
+
+#include <windows.h>
+
+#include <cstddef>
+#include <string>
+
+namespace winapi {
+
+class Sid {
+public:
+    BOOST_STATIC_CONSTEXPR std::size_t MAX_SID_SIZE = SECURITY_MAX_SID_SIZE;
+
+    typedef SID Impl;
+
+    static Sid well_known(WELL_KNOWN_SID_TYPE type);
+
+    static Sid builtin_administrators();
+
+    explicit Sid(const Buffer& buffer) : m_buffer(buffer) {}
+
+    explicit operator SID&() { return get_impl(); }
+    explicit operator const SID&() const { return get_impl(); }
+
+    std::string to_string() const;
+
+private:
+    Impl& get_impl() { return *reinterpret_cast<SID*>(m_buffer.data()); }
+    const Impl& get_impl() const { return *reinterpret_cast<const SID*>(m_buffer.data()); }
+
+    Buffer m_buffer;
+};
+
+} // namespace winapi
diff --git a/include/winapi/workarounds.hpp b/include/winapi/utils.hpp
index a5a3607..8e8407c 100644
--- a/include/winapi/workarounds.hpp
+++ b/include/winapi/utils.hpp
@@ -5,4 +5,20 @@
 
 #pragma once
 
+#include <windows.h>
+
+#include <cassert>
+
 #define WINAPI_UNUSED_PARAMETER(...) (void)(__VA_ARGS__)
+
+namespace winapi {
+
+struct LocalDelete {
+    void operator()(void* ptr) const {
+        const auto ret = ::LocalFree(ptr);
+        assert(ret == NULL);
+        WINAPI_UNUSED_PARAMETER(ret);
+    }
+};
+
+} // namespace winapi
diff --git a/src/cmd_line.cpp b/src/cmd_line.cpp
index eaf505f..d3dc781 100644
--- a/src/cmd_line.cpp
+++ b/src/cmd_line.cpp
@@ -6,6 +6,7 @@
 #include <winapi/cmd_line.hpp>
 #include <winapi/error.hpp>
 #include <winapi/utf8.hpp>
+#include <winapi/utils.hpp>
 
 #include <boost/algorithm/string.hpp>
 #include <boost/config.hpp>
@@ -34,10 +35,6 @@ std::vector<std::string> narrow_all(int argc, wchar_t** argv) {
     return utf;
 }
 
-struct LocalDelete {
-    void operator()(wchar_t* argv[]) const { ::LocalFree(argv); }
-};
-
 CommandLine do_parse(std::wstring src) {
     boost::trim(src);
     if (src.empty()) {
diff --git a/src/handle.cpp b/src/handle.cpp
index 1147cf6..c94cb16 100644
--- a/src/handle.cpp
+++ b/src/handle.cpp
@@ -6,7 +6,7 @@
 #include <winapi/buffer.hpp>
 #include <winapi/error.hpp>
 #include <winapi/handle.hpp>
-#include <winapi/workarounds.hpp>
+#include <winapi/utils.hpp>
 
 #include <boost/config.hpp>
 
diff --git a/src/sid.cpp b/src/sid.cpp
new file mode 100644
index 0000000..23be61a
--- /dev/null
+++ b/src/sid.cpp
@@ -0,0 +1,48 @@
+// Copyright (c) 2020 Egor Tensin <Egor.Tensin@gmail.com>
+// This file is part of the "winapi-common" project.
+// For details, see https://github.com/egor-tensin/winapi-common.
+// Distributed under the MIT License.
+
+#include <winapi/buffer.hpp>
+#include <winapi/error.hpp>
+#include <winapi/sid.hpp>
+#include <winapi/utf8.hpp>
+#include <winapi/utils.hpp>
+
+// clang-format off
+#include <windows.h>
+#include <sddl.h>
+// clang-format on
+
+#include <memory>
+#include <string>
+
+namespace winapi {
+
+Sid Sid::well_known(WELL_KNOWN_SID_TYPE type) {
+    Buffer buffer;
+    buffer.resize(MAX_SID_SIZE);
+
+    DWORD cb = static_cast<DWORD>(buffer.size());
+
+    if (!::CreateWellKnownSid(type, NULL, buffer.data(), &cb))
+        throw error::windows(GetLastError(), "CreateWellKnownSid");
+
+    buffer.resize(cb);
+    return Sid{buffer};
+}
+
+Sid Sid::builtin_administrators() {
+    return well_known(WinBuiltinAdministratorsSid);
+}
+
+std::string Sid::to_string() const {
+    wchar_t* s = nullptr;
+
+    if (!::ConvertSidToStringSidW(const_cast<Impl*>(&get_impl()), &s))
+        throw error::windows(GetLastError(), "ConvertSidToStringSidW");
+
+    return narrow(std::unique_ptr<wchar_t, LocalDelete>{s}.get());
+}
+
+} // namespace winapi
diff --git a/test/unit_tests/sid.cpp b/test/unit_tests/sid.cpp
new file mode 100644
index 0000000..757f6f4
--- /dev/null
+++ b/test/unit_tests/sid.cpp
@@ -0,0 +1,19 @@
+// Copyright (c) 2020 Egor Tensin <Egor.Tensin@gmail.com>
+// This file is part of the "winapi-common" project.
+// For details, see https://github.com/egor-tensin/winapi-common.
+// Distributed under the MIT License.
+
+#include <winapi/sid.hpp>
+
+#include <boost/test/unit_test.hpp>
+
+using namespace winapi;
+
+BOOST_AUTO_TEST_SUITE(sid_tests)
+
+BOOST_AUTO_TEST_CASE(builtin_administrators) {
+    const auto sid = Sid::builtin_administrators();
+    BOOST_TEST(sid.to_string() == "S-1-5-32-544");
+}
+
+BOOST_AUTO_TEST_SUITE_END()