[Chromoting] Call SendSAS() directly from the host.

In order to call SendSAS() successfully the calling process's binary has to:
 - be signed.
 - be installed under %ProgramFiles% or %SystemRoot%\system32.
 - specify uiAccess='true' in the manifest.
 - run under SYSTEM or the currently logged-on user.

All of those requirements are met now, so SendSAS() can be called directly.

BUG=135217

Review URL: https://chromiumcodereview.appspot.com/10836224

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@152191 0039d316-1c4b-4281-b951-d872f2087c98

remoting/host/chromoting_messages.h

@@ -8,10 +8,3 @@
 #include "ipc/ipc_message_macros.h"
 
 #define IPC_MESSAGE_START ChromotingMsgStart
-
-//-----------------------------------------------------------------------------
-// The Chrmomoting session messages
-
-// Asks the service to send the Secure Attention Sequence (SAS) to the current
-// console session.
-IPC_MESSAGE_CONTROL0(ChromotingHostMsg_SendSasToConsole)

remoting/host/sas_injector_win.cc

@@ -14,14 +14,15 @@
 #include "base/utf_string_conversions.h"
 #include "base/win/registry.h"
 #include "base/win/windows_version.h"
+#include "remoting/host/win/desktop.h"
+#include "remoting/host/win/scoped_thread_desktop.h"
 
 namespace remoting {
 
 namespace {
 
 // Names of the API and library implementing software SAS generation.
-const FilePath::CharType kSasDllFileName[] =
-    FILE_PATH_LITERAL("sas.dll");
+const FilePath::CharType kSasDllFileName[] = FILE_PATH_LITERAL("sas.dll");
 const char kSendSasName[] = "SendSAS";
 
 // The prototype of SendSAS().
@@ -33,10 +34,10 @@ const wchar_t kSystemPolicyKeyName[] =
     L"Software\\Microsoft\\Windows\\CurrentVersion\\Policies\\System";
 const wchar_t kSoftwareSasValueName[] = L"SoftwareSASGeneration";
 
-const DWORD kEnableSoftwareSasByServices = 1;
+const DWORD kEnableSoftwareSasByApps = 2;
 
 // Toggles the default software SAS generation policy to enable SAS generation
-// by services. Non-default policy is not changed.
+// by applications. Non-default policy is not changed.
 class ScopedSoftwareSasPolicy {
  public:
   ScopedSoftwareSasPolicy();
@@ -88,7 +89,7 @@ bool ScopedSoftwareSasPolicy::Apply() {
   // Override the default policy (i.e. there is no value in the registry) only.
   if (!custom_policy) {
     result = system_policy_.WriteValue(kSoftwareSasValueName,
-                                       kEnableSoftwareSasByServices);
+                                       kEnableSoftwareSasByApps);
     if (result != ERROR_SUCCESS) {
       SetLastError(result);
       LOG_GETLASTERROR(ERROR)
@@ -121,6 +122,18 @@ class SasInjectorWin : public SasInjector {
   SendSasFunc send_sas_;
 };
 
+// Emulates Secure Attention Sequence (Ctrl+Alt+Del) by switching to
+// the Winlogon desktop and injecting Ctrl+Alt+Del as a hot key.
+// N.B. Windows XP/W2K3 only.
+class SasInjectorXp : public SasInjector {
+ public:
+  SasInjectorXp();
+  virtual ~SasInjectorXp();
+
+  // SasInjector implementation.
+  virtual bool InjectSas() OVERRIDE;
+};
+
 SasInjectorWin::SasInjectorWin() : send_sas_(NULL) {
 }
 
@@ -157,7 +170,7 @@ bool SasInjectorWin::InjectSas() {
   }
 
   // Enable software SAS generation by services and send SAS. SAS can still fail
-  // if the policy does not allow services to generate software SAS.
+  // if the policy does not allow applications to generate software SAS.
   ScopedSoftwareSasPolicy enable_sas;
   if (!enable_sas.Apply())
     return false;
@@ -166,12 +179,43 @@ bool SasInjectorWin::InjectSas() {
   return true;
 }
 
+SasInjectorXp::SasInjectorXp() {
+}
+
+SasInjectorXp::~SasInjectorXp() {
+}
+
+bool SasInjectorXp::InjectSas() {
+  const wchar_t kWinlogonDesktopName[] = L"Winlogon";
+  const wchar_t kSasWindowClassName[] = L"SAS window class";
+  const wchar_t kSasWindowTitle[] = L"SAS window";
+
+  scoped_ptr<remoting::Desktop> winlogon_desktop(
+      remoting::Desktop::GetDesktop(kWinlogonDesktopName));
+  if (!winlogon_desktop.get())
+    return false;
+
+  remoting::ScopedThreadDesktop desktop;
+  if (!desktop.SetThreadDesktop(winlogon_desktop.Pass()))
+    return false;
+
+  HWND window = FindWindow(kSasWindowClassName, kSasWindowTitle);
+  if (!window)
+    return false;
+
+  PostMessage(window,
+              WM_HOTKEY,
+              0,
+              MAKELONG(MOD_ALT | MOD_CONTROL, VK_DELETE));
+  return true;
+}
+
 scoped_ptr<SasInjector> SasInjector::Create() {
-  if (base::win::GetVersion() >= base::win::VERSION_VISTA) {
+  if (base::win::GetVersion() < base::win::VERSION_VISTA) {
+    return scoped_ptr<SasInjector>(new SasInjectorXp());
+  } else {
     return scoped_ptr<SasInjector>(new SasInjectorWin());
   }
-
-  return scoped_ptr<SasInjector>();
 }
 
 } // namespace remoting

remoting/host/session_event_executor_win.cc

@@ -14,15 +14,12 @@
 #include "ipc/ipc_channel.h"
 #include "ipc/ipc_channel_proxy.h"
 #include "remoting/host/chromoting_messages.h"
+#include "remoting/host/sas_injector.h"
 #include "remoting/host/win/desktop.h"
-#include "remoting/host/win/scoped_thread_desktop.h"
 #include "remoting/proto/event.pb.h"
 
 namespace {
 
-// The command line switch specifying the name of the Chromoting IPC channel.
-const char kProcessChannelId[] = "chromoting-ipc";
-
 const uint32 kUsbLeftControl =  0x0700e0;
 const uint32 kUsbRightControl = 0x0700e4;
 const uint32 kUsbLeftAlt =  0x0700e2;
@@ -38,33 +35,6 @@ bool CheckCtrlAndAltArePressed(const std::set<uint32>& pressed_keys) {
     (ctrl_keys + alt_keys == pressed_keys.size());
 }
 
-// Emulates Secure Attention Sequence (Ctrl+Alt+Del) by switching to
-// the Winlogon desktop and injecting Ctrl+Alt+Del as a hot key.
-// N.B. Windows XP/W2K3 only.
-void EmulateSecureAttentionSequence() {
-  const wchar_t kWinlogonDesktopName[] = L"Winlogon";
-  const wchar_t kSasWindowClassName[] = L"SAS window class";
-  const wchar_t kSasWindowTitle[] = L"SAS window";
-
-  scoped_ptr<remoting::Desktop> winlogon_desktop(
-      remoting::Desktop::GetDesktop(kWinlogonDesktopName));
-  if (!winlogon_desktop.get())
-    return;
-
-  remoting::ScopedThreadDesktop desktop;
-  if (!desktop.SetThreadDesktop(winlogon_desktop.Pass()))
-    return;
-
-  HWND window = FindWindow(kSasWindowClassName, kSasWindowTitle);
-  if (!window)
-    return;
-
-  PostMessage(window,
-              WM_HOTKEY,
-              0,
-              MAKELONG(MOD_ALT | MOD_CONTROL, VK_DELETE));
-}
-
 } // namespace
 
 namespace remoting {
@@ -85,16 +55,6 @@ SessionEventExecutorWin::SessionEventExecutorWin(
   // |weak_ptr_| and |weak_ptr_factory_| share a ThreadChecker, so the
   // following line affects both of them.
   weak_ptr_factory_.DetachFromThread();
-
-  std::string channel_name =
-      CommandLine::ForCurrentProcess()->GetSwitchValueASCII(kProcessChannelId);
-
-  // Connect to the Chromoting IPC channel if the name was passed in the command
-  // line.
-  if (!channel_name.empty()) {
-    chromoting_channel_.reset(new IPC::ChannelProxy(
-        channel_name, IPC::Channel::MODE_CLIENT, this, io_task_runner));
-  }
 }
 
 SessionEventExecutorWin::~SessionEventExecutorWin() {
@@ -157,11 +117,9 @@ void SessionEventExecutorWin::InjectKeyEvent(const KeyEvent& event) {
           CheckCtrlAndAltArePressed(pressed_keys_)) {
         VLOG(3) << "Sending Secure Attention Sequence to console";
 
-        if (base::win::GetVersion() == base::win::VERSION_XP) {
-          EmulateSecureAttentionSequence();
-        } else if (chromoting_channel_.get()) {
-          chromoting_channel_->Send(new ChromotingHostMsg_SendSasToConsole());
-        }
+        if (sas_injector_.get() == NULL)
+          sas_injector_ = SasInjector::Create();
+        sas_injector_->InjectSas();
       }
 
       pressed_keys_.insert(event.usb_keycode());
@@ -187,10 +145,6 @@ void SessionEventExecutorWin::InjectMouseEvent(const MouseEvent& event) {
   nested_executor_->InjectMouseEvent(event);
 }
 
-bool SessionEventExecutorWin::OnMessageReceived(const IPC::Message& message) {
-  return false;
-}
-
 void SessionEventExecutorWin::SwitchToInputDesktop() {
   // Switch to the desktop receiving user input if different from the current
   // one.

remoting/host/session_event_executor_win.h

@@ -24,8 +24,9 @@ class ChannelProxy;
 
 namespace remoting {
 
-class SessionEventExecutorWin : public EventExecutor,
-                                public IPC::Listener {
+class SasInjector;
+
+class SessionEventExecutorWin : public EventExecutor {
  public:
   SessionEventExecutorWin(
       scoped_refptr<base::SingleThreadTaskRunner> main_task_runner,
@@ -46,9 +47,6 @@ class SessionEventExecutorWin : public EventExecutor,
   virtual void InjectKeyEvent(const protocol::KeyEvent& event) OVERRIDE;
   virtual void InjectMouseEvent(const protocol::MouseEvent& event) OVERRIDE;
 
-  // IPC::Listener implementation.
-  virtual bool OnMessageReceived(const IPC::Message& message) OVERRIDE;
-
  private:
   // Switches to the desktop receiving a user input if different from
   // the current one.
@@ -61,8 +59,7 @@ class SessionEventExecutorWin : public EventExecutor,
 
   ScopedThreadDesktop desktop_;
 
-  // The Chromoting IPC channel connecting the host with the service.
-  scoped_ptr<IPC::ChannelProxy> chromoting_channel_;
+  scoped_ptr<SasInjector> sas_injector_;
 
   // Keys currently pressed by the client, used to detect Ctrl-Alt-Del.
   std::set<uint32> pressed_keys_;

remoting/host/win/wts_session_process_launcher.cc

@@ -30,7 +30,6 @@
 #include "ipc/ipc_message_macros.h"
 #include "remoting/host/constants.h"
 #include "remoting/host/chromoting_messages.h"
-#include "remoting/host/sas_injector.h"
 #include "remoting/host/win/launch_process_with_token.h"
 #include "remoting/host/win/wts_console_monitor.h"
 
@@ -207,13 +206,7 @@ void WtsSessionProcessLauncher::OnChannelConnected() {
 bool WtsSessionProcessLauncher::OnMessageReceived(const IPC::Message& message) {
   DCHECK(main_message_loop_->BelongsToCurrentThread());
 
-  bool handled = true;
-  IPC_BEGIN_MESSAGE_MAP(WtsSessionProcessLauncher, message)
-      IPC_MESSAGE_HANDLER(ChromotingHostMsg_SendSasToConsole,
-                          OnSendSasToConsole)
-      IPC_MESSAGE_UNHANDLED(handled = false)
-  IPC_END_MESSAGE_MAP()
-  return handled;
+  return false;
 }
 
 void WtsSessionProcessLauncher::OnSessionAttached(uint32 session_id) {
@@ -441,18 +434,4 @@ void WtsSessionProcessLauncher::OnLauncherStopped() {
   }
 }
 
-void WtsSessionProcessLauncher::OnSendSasToConsole() {
-  DCHECK(main_message_loop_->BelongsToCurrentThread());
-
-  if (attached_) {
-    if (sas_injector_.get() == NULL) {
-      sas_injector_ = SasInjector::Create();
-    }
-
-    if (sas_injector_.get() != NULL) {
-      sas_injector_->InjectSas();
-    }
-  }
-}
-
 } // namespace remoting

remoting/host/win/wts_session_process_launcher.h

@@ -32,7 +32,6 @@ class Message;
 
 namespace remoting {
 
-class SasInjector;
 class WtsConsoleMonitor;
 
 class WtsSessionProcessLauncher
@@ -99,10 +98,6 @@ class WtsSessionProcessLauncher
   // Called when the launcher reports the process to be stopped.
   void OnLauncherStopped();
 
-  // Sends the Secure Attention Sequence to the session represented by
-  // |session_token_|.
-  void OnSendSasToConsole();
-
   // |true| if this object is currently attached to the console session.
   bool attached_;
 
@@ -147,8 +142,6 @@ class WtsSessionProcessLauncher
   // The token to be used to launch a process in a different session.
   base::win::ScopedHandle session_token_;
 
-  scoped_ptr<SasInjector> sas_injector_;
-
   DISALLOW_COPY_AND_ASSIGN(WtsSessionProcessLauncher);
 };
 

remoting/remoting.gyp

@@ -597,8 +597,6 @@
             'host/daemon_process.cc',
             'host/daemon_process.h',
             'host/daemon_process_win.cc',
-            'host/sas_injector.h',
-            'host/sas_injector_win.cc',
             'host/usage_stats_consent.h',
             'host/usage_stats_consent_win.cc',
             'host/win/host_service.cc',
@@ -1274,6 +1272,8 @@
         'host/register_support_host_request.h',
         'host/remote_input_filter.cc',
         'host/remote_input_filter.h',
+        'host/sas_injector.h',
+        'host/sas_injector_win.cc',
         'host/screen_recorder.cc',
         'host/screen_recorder.h',
         'host/server_log_entry.cc',