The Tor Browser: security/sandbox/win/src/restricted_token

security/sandbox/win/src/restricted_token_utils.cc@6474c204b198 (annotated)

security/sandbox/win/src/restricted_token_utils.cc

Wed, 31 Dec 2014 06:09:35 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Wed, 31 Dec 2014 06:09:35 +0100
changeset 0: 6474c204b198
permissions: -rw-r--r--

Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 #include <aclapi.h>
 #include <sddl.h>
 #include <vector>
 #include "sandbox/win/src/restricted_token_utils.h"
 #include "base/logging.h"
 #include "base/win/scoped_handle.h"
 #include "base/win/scoped_process_information.h"
 #include "base/win/windows_version.h"
 #include "sandbox/win/src/job.h"
 #include "sandbox/win/src/restricted_token.h"
 #include "sandbox/win/src/security_level.h"
 #include "sandbox/win/src/sid.h"
 namespace sandbox {
 DWORD CreateRestrictedToken(HANDLE *token_handle,
                             TokenLevel security_level,
                             IntegrityLevel integrity_level,
                             TokenType token_type) {
   if (!token_handle)
     return ERROR_BAD_ARGUMENTS;
   RestrictedToken restricted_token;
   restricted_token.Init(NULL);  // Initialized with the current process token
   std::vector<std::wstring> privilege_exceptions;
   std::vector<Sid> sid_exceptions;
   bool deny_sids = true;
   bool remove_privileges = true;
   switch (security_level) {
     case USER_UNPROTECTED: {
       deny_sids = false;
       remove_privileges = false;
       break;
     }
     case USER_RESTRICTED_SAME_ACCESS: {
       deny_sids = false;
       remove_privileges = false;
       unsigned err_code = restricted_token.AddRestrictingSidAllSids();
       if (ERROR_SUCCESS != err_code)
         return err_code;
       break;
     }
     case USER_NON_ADMIN: {
       sid_exceptions.push_back(WinBuiltinUsersSid);
       sid_exceptions.push_back(WinWorldSid);
       sid_exceptions.push_back(WinInteractiveSid);
       sid_exceptions.push_back(WinAuthenticatedUserSid);
       privilege_exceptions.push_back(SE_CHANGE_NOTIFY_NAME);
       break;
     }
     case USER_INTERACTIVE: {
       sid_exceptions.push_back(WinBuiltinUsersSid);
       sid_exceptions.push_back(WinWorldSid);
       sid_exceptions.push_back(WinInteractiveSid);
       sid_exceptions.push_back(WinAuthenticatedUserSid);
       privilege_exceptions.push_back(SE_CHANGE_NOTIFY_NAME);
       restricted_token.AddRestrictingSid(WinBuiltinUsersSid);
       restricted_token.AddRestrictingSid(WinWorldSid);
       restricted_token.AddRestrictingSid(WinRestrictedCodeSid);
       restricted_token.AddRestrictingSidCurrentUser();
       restricted_token.AddRestrictingSidLogonSession();
       break;
     }
     case USER_LIMITED: {
       sid_exceptions.push_back(WinBuiltinUsersSid);
       sid_exceptions.push_back(WinWorldSid);
       sid_exceptions.push_back(WinInteractiveSid);
       privilege_exceptions.push_back(SE_CHANGE_NOTIFY_NAME);
       restricted_token.AddRestrictingSid(WinBuiltinUsersSid);
       restricted_token.AddRestrictingSid(WinWorldSid);
       restricted_token.AddRestrictingSid(WinRestrictedCodeSid);
       // This token has to be able to create objects in BNO.
       // Unfortunately, on vista, it needs the current logon sid
       // in the token to achieve this. You should also set the process to be
       // low integrity level so it can't access object created by other
       // processes.
       if (base::win::GetVersion() >= base::win::VERSION_VISTA)
         restricted_token.AddRestrictingSidLogonSession();
       break;
     }
     case USER_RESTRICTED: {
       privilege_exceptions.push_back(SE_CHANGE_NOTIFY_NAME);
       restricted_token.AddUserSidForDenyOnly();
       restricted_token.AddRestrictingSid(WinRestrictedCodeSid);
       break;
     }
     case USER_LOCKDOWN: {
       restricted_token.AddUserSidForDenyOnly();
       restricted_token.AddRestrictingSid(WinNullSid);
       break;
     }
     default: {
       return ERROR_BAD_ARGUMENTS;
     }
   }
   DWORD err_code = ERROR_SUCCESS;
   if (deny_sids) {
     err_code = restricted_token.AddAllSidsForDenyOnly(&sid_exceptions);
     if (ERROR_SUCCESS != err_code)
       return err_code;
   }
   if (remove_privileges) {
     err_code = restricted_token.DeleteAllPrivileges(&privilege_exceptions);
     if (ERROR_SUCCESS != err_code)
       return err_code;
   }
   restricted_token.SetIntegrityLevel(integrity_level);
   switch (token_type) {
     case PRIMARY: {
       err_code = restricted_token.GetRestrictedTokenHandle(token_handle);
       break;
     }
     case IMPERSONATION: {
       err_code = restricted_token.GetRestrictedTokenHandleForImpersonation(
           token_handle);
       break;
     }
     default: {
       err_code = ERROR_BAD_ARGUMENTS;
       break;
     }
   }
   return err_code;
 }
 DWORD StartRestrictedProcessInJob(wchar_t *command_line,
                                   TokenLevel primary_level,
                                   TokenLevel impersonation_level,
                                   JobLevel job_level,
                                   HANDLE *const job_handle_ret) {
   Job job;
   DWORD err_code = job.Init(job_level, NULL, 0);
   if (ERROR_SUCCESS != err_code)
     return err_code;
   if (JOB_UNPROTECTED != job_level) {
     // Share the Desktop handle to be able to use MessageBox() in the sandboxed
     // application.
     err_code = job.UserHandleGrantAccess(GetDesktopWindow());
     if (ERROR_SUCCESS != err_code)
       return err_code;
   }
   // Create the primary (restricted) token for the process
   HANDLE primary_token_handle = NULL;
   err_code = CreateRestrictedToken(&primary_token_handle,
                                    primary_level,
                                    INTEGRITY_LEVEL_LAST,
                                    PRIMARY);
   if (ERROR_SUCCESS != err_code) {
     return err_code;
   }
   base::win::ScopedHandle primary_token(primary_token_handle);
   // Create the impersonation token (restricted) to be able to start the
   // process.
   HANDLE impersonation_token_handle;
   err_code = CreateRestrictedToken(&impersonation_token_handle,
                                    impersonation_level,
                                    INTEGRITY_LEVEL_LAST,
                                    IMPERSONATION);
   if (ERROR_SUCCESS != err_code) {
     return err_code;
   }
   base::win::ScopedHandle impersonation_token(impersonation_token_handle);
   // Start the process
   STARTUPINFO startup_info = {0};
   base::win::ScopedProcessInformation process_info;
   DWORD flags = CREATE_SUSPENDED;
   if (base::win::GetVersion() < base::win::VERSION_WIN8) {
     // Windows 8 implements nested jobs, but for older systems we need to
     // break out of any job we're in to enforce our restrictions.
     flags |= CREATE_BREAKAWAY_FROM_JOB;
   }
   if (!::CreateProcessAsUser(primary_token.Get(),
                              NULL,   // No application name.
                              command_line,
                              NULL,   // No security attribute.
                              NULL,   // No thread attribute.
                              FALSE,  // Do not inherit handles.
                              flags,
                              NULL,   // Use the environment of the caller.
                              NULL,   // Use current directory of the caller.
                              &startup_info,
                              process_info.Receive())) {
     return ::GetLastError();
   }
   // Change the token of the main thread of the new process for the
   // impersonation token with more rights.
   {
     HANDLE temp_thread = process_info.thread_handle();
     if (!::SetThreadToken(&temp_thread, impersonation_token.Get())) {
       ::TerminateProcess(process_info.process_handle(),
 );  // exit code
       return ::GetLastError();
     }
   }
   err_code = job.AssignProcessToJob(process_info.process_handle());
   if (ERROR_SUCCESS != err_code) {
     ::TerminateProcess(process_info.process_handle(),
 );  // exit code
     return ::GetLastError();
   }
   // Start the application
   ::ResumeThread(process_info.thread_handle());
   (*job_handle_ret) = job.Detach();
   return ERROR_SUCCESS;
 }
 DWORD SetObjectIntegrityLabel(HANDLE handle, SE_OBJECT_TYPE type,
                               const wchar_t* ace_access,
                               const wchar_t* integrity_level_sid) {
   // Build the SDDL string for the label.
   std::wstring sddl = L"S:(";     // SDDL for a SACL.
   sddl += SDDL_MANDATORY_LABEL;   // Ace Type is "Mandatory Label".
   sddl += L";;";                  // No Ace Flags.
   sddl += ace_access;             // Add the ACE access.
   sddl += L";;;";                 // No ObjectType and Inherited Object Type.
   sddl += integrity_level_sid;    // Trustee Sid.
   sddl += L")";
   DWORD error = ERROR_SUCCESS;
   PSECURITY_DESCRIPTOR sec_desc = NULL;
   PACL sacl = NULL;
   BOOL sacl_present = FALSE;
   BOOL sacl_defaulted = FALSE;
   if (::ConvertStringSecurityDescriptorToSecurityDescriptorW(sddl.c_str(),
                                                              SDDL_REVISION,
                                                              &sec_desc, NULL)) {
     if (::GetSecurityDescriptorSacl(sec_desc, &sacl_present, &sacl,
                                     &sacl_defaulted)) {
       error = ::SetSecurityInfo(handle, type,
                                 LABEL_SECURITY_INFORMATION, NULL, NULL, NULL,
                                 sacl);
     } else {
       error = ::GetLastError();
     }
     ::LocalFree(sec_desc);
   } else {
     return::GetLastError();
   }
   return error;
 }
 const wchar_t* GetIntegrityLevelString(IntegrityLevel integrity_level) {
   switch (integrity_level) {
     case INTEGRITY_LEVEL_SYSTEM:
       return L"S-1-16-16384";
     case INTEGRITY_LEVEL_HIGH:
       return L"S-1-16-12288";
     case INTEGRITY_LEVEL_MEDIUM:
       return L"S-1-16-8192";
     case INTEGRITY_LEVEL_MEDIUM_LOW:
       return L"S-1-16-6144";
     case INTEGRITY_LEVEL_LOW:
       return L"S-1-16-4096";
     case INTEGRITY_LEVEL_BELOW_LOW:
       return L"S-1-16-2048";
     case INTEGRITY_LEVEL_UNTRUSTED:
       return L"S-1-16-0";
     case INTEGRITY_LEVEL_LAST:
       return NULL;
   }
   NOTREACHED();
   return NULL;
 }
 DWORD SetTokenIntegrityLevel(HANDLE token, IntegrityLevel integrity_level) {
   if (base::win::GetVersion() < base::win::VERSION_VISTA)
     return ERROR_SUCCESS;
   const wchar_t* integrity_level_str = GetIntegrityLevelString(integrity_level);
   if (!integrity_level_str) {
     // No mandatory level specified, we don't change it.
     return ERROR_SUCCESS;
   }
   PSID integrity_sid = NULL;
   if (!::ConvertStringSidToSid(integrity_level_str, &integrity_sid))
     return ::GetLastError();
   TOKEN_MANDATORY_LABEL label = {0};
   label.Label.Attributes = SE_GROUP_INTEGRITY;
   label.Label.Sid = integrity_sid;
   DWORD size = sizeof(TOKEN_MANDATORY_LABEL) + ::GetLengthSid(integrity_sid);
   BOOL result = ::SetTokenInformation(token, TokenIntegrityLevel, &label,
                                       size);
   ::LocalFree(integrity_sid);
   return result ? ERROR_SUCCESS : ::GetLastError();
 }
 DWORD SetProcessIntegrityLevel(IntegrityLevel integrity_level) {
   if (base::win::GetVersion() < base::win::VERSION_VISTA)
     return ERROR_SUCCESS;
   // We don't check for an invalid level here because we'll just let it
   // fail on the SetTokenIntegrityLevel call later on.
   if (integrity_level == INTEGRITY_LEVEL_LAST) {
     // No mandatory level specified, we don't change it.
     return ERROR_SUCCESS;
   }
   HANDLE token_handle;
   if (!::OpenProcessToken(GetCurrentProcess(), TOKEN_ADJUST_DEFAULT,
                           &token_handle))
     return ::GetLastError();
   base::win::ScopedHandle token(token_handle);
   return SetTokenIntegrityLevel(token.Get(), integrity_level);
 }
 }  // namespace sandbox

The Tor Browser / annotate

security/sandbox/win/src/restricted_token_utils.cc@6474c204b198 (annotated)

security/sandbox/win/src/restricted_token_utils.cc