use shell execute to run cmd as Admin - delphi

Question

I need to run cmd on a button click as admin. It works. but I need to run it as an admin. How is this done?
ShellExecute(Handle, 'open', 'c:\Windows\system32\cmd.exe', nil, nil, SW_SHOWNORMAL)

Answer 1

Replace the open verb with the runas as shown below. Anyway, try to avoid path hardcoding:
uses
ShellAPI;
procedure TForm1.Button1Click(Sender: TObject);
begin
ShellExecute(Handle, 'runas', 'cmd.exe', nil, nil, SW_SHOWNORMAL);
end;
You can also add to your button the shield icon by setting the ElevationRequired property to True.

Answer 2

ShellExecute/Ex() with the "runas" verb is the only official way to start an elevated process programmably, especially if the executable being run does not have its own UAC manifest to invoke elevation.
However, that is not the only way to start an elevated process. Have a look at the following article, which explains elevation in detail and offers alternative implementations, like CreateProcessElevated() and ShellExecuteElevated(), which are more flexible:
Vista UAC: The Definitive Guide

Answer 3

This is sample code to use ShellExecute + runas to run routines elevated (i.e. under full administrator account). It should work with both UAC enabled/disabled + in older Windows versions (before Windows Vista).
unit RunElevatedSupport;
{$WARN SYMBOL_PLATFORM OFF}
{$R+}
interface
uses
Windows;
type
TElevatedProc = function(const AParameters: String): Cardinal;
TProcessMessagesMeth = procedure of object;
var
// Warning: this function will be executed in external process.
// Do not use any global variables inside this routine!
// Use only supplied AParameters.
OnElevateProc: TElevatedProc;
// Call this routine after you have assigned OnElevateProc
procedure CheckForElevatedTask;
// Runs OnElevateProc under full administrator rights
function RunElevated(const AParameters: String; const AWnd: HWND = 0; const AProcessMessages: TProcessMessagesMeth = nil): Cardinal; overload;
function IsAdministrator: Boolean;
function IsAdministratorAccount: Boolean;
function IsUACEnabled: Boolean;
function IsElevated: Boolean;
procedure SetButtonElevated(const AButtonHandle: THandle);
implementation
uses
SysUtils, Registry, ShellAPI, ComObj;
const
RunElevatedTaskSwitch = '0CC5C50CB7D643B68CB900BF000FFFD5'; // some unique value, just a GUID with removed '[', ']', and '-'
function CheckTokenMembership(TokenHandle: THANDLE; SidToCheck: Pointer; var IsMember: BOOL): BOOL; stdcall; external advapi32 name 'CheckTokenMembership';
function RunElevated(const AParameters: String; const AWnd: HWND = 0; const AProcessMessages: TProcessMessagesMeth = nil): Cardinal; overload;
var
SEI: TShellExecuteInfo;
Host: String;
Args: String;
begin
Assert(Assigned(OnElevateProc), 'OnElevateProc must be assigned before calling RunElevated');
if IsElevated then
begin
if Assigned(OnElevateProc) then
Result := OnElevateProc(AParameters)
else
Result := ERROR_PROC_NOT_FOUND;
Exit;
end;
Host := ParamStr(0);
Args := Format('/%s %s', [RunElevatedTaskSwitch, AParameters]);
FillChar(SEI, SizeOf(SEI), 0);
SEI.cbSize := SizeOf(SEI);
SEI.fMask := SEE_MASK_NOCLOSEPROCESS;
{$IFDEF UNICODE}
SEI.fMask := SEI.fMask or SEE_MASK_UNICODE;
{$ENDIF}
SEI.Wnd := AWnd;
SEI.lpVerb := 'runas';
SEI.lpFile := PChar(Host);
SEI.lpParameters := PChar(Args);
SEI.nShow := SW_NORMAL;
if not ShellExecuteEx(#SEI) then
RaiseLastOSError;
try
Result := ERROR_GEN_FAILURE;
if Assigned(AProcessMessages) then
begin
repeat
if not GetExitCodeProcess(SEI.hProcess, Result) then
Result := ERROR_GEN_FAILURE;
AProcessMessages;
until Result <> STILL_ACTIVE;
end
else
begin
if WaitForSingleObject(SEI.hProcess, INFINITE) <> WAIT_OBJECT_0 then
if not GetExitCodeProcess(SEI.hProcess, Result) then
Result := ERROR_GEN_FAILURE;
end;
finally
CloseHandle(SEI.hProcess);
end;
end;
function IsAdministrator: Boolean;
var
psidAdmin: Pointer;
B: BOOL;
const
SECURITY_NT_AUTHORITY: TSidIdentifierAuthority = (Value: (0, 0, 0, 0, 0, 5));
SECURITY_BUILTIN_DOMAIN_RID = $00000020;
DOMAIN_ALIAS_RID_ADMINS = $00000220;
SE_GROUP_USE_FOR_DENY_ONLY = $00000010;
begin
psidAdmin := nil;
try
// Создаём SID группы админов для проверки
Win32Check(AllocateAndInitializeSid(SECURITY_NT_AUTHORITY, 2,
SECURITY_BUILTIN_DOMAIN_RID, DOMAIN_ALIAS_RID_ADMINS, 0, 0, 0, 0, 0, 0,
psidAdmin));
// Проверяем, входим ли мы в группу админов (с учётов всех проверок на disabled SID)
if CheckTokenMembership(0, psidAdmin, B) then
Result := B
else
Result := False;
finally
if psidAdmin <> nil then
FreeSid(psidAdmin);
end;
end;
{$R-}
function IsAdministratorAccount: Boolean;
var
psidAdmin: Pointer;
Token: THandle;
Count: DWORD;
TokenInfo: PTokenGroups;
HaveToken: Boolean;
I: Integer;
const
SECURITY_NT_AUTHORITY: TSidIdentifierAuthority = (Value: (0, 0, 0, 0, 0, 5));
SECURITY_BUILTIN_DOMAIN_RID = $00000020;
DOMAIN_ALIAS_RID_ADMINS = $00000220;
SE_GROUP_USE_FOR_DENY_ONLY = $00000010;
begin
Result := Win32Platform <> VER_PLATFORM_WIN32_NT;
if Result then
Exit;
psidAdmin := nil;
TokenInfo := nil;
HaveToken := False;
try
Token := 0;
HaveToken := OpenThreadToken(GetCurrentThread, TOKEN_QUERY, True, Token);
if (not HaveToken) and (GetLastError = ERROR_NO_TOKEN) then
HaveToken := OpenProcessToken(GetCurrentProcess, TOKEN_QUERY, Token);
if HaveToken then
begin
Win32Check(AllocateAndInitializeSid(SECURITY_NT_AUTHORITY, 2,
SECURITY_BUILTIN_DOMAIN_RID, DOMAIN_ALIAS_RID_ADMINS, 0, 0, 0, 0, 0, 0,
psidAdmin));
if GetTokenInformation(Token, TokenGroups, nil, 0, Count) or
(GetLastError <> ERROR_INSUFFICIENT_BUFFER) then
RaiseLastOSError;
TokenInfo := PTokenGroups(AllocMem(Count));
Win32Check(GetTokenInformation(Token, TokenGroups, TokenInfo, Count, Count));
for I := 0 to TokenInfo^.GroupCount - 1 do
begin
Result := EqualSid(psidAdmin, TokenInfo^.Groups[I].Sid);
if Result then
Break;
end;
end;
finally
if TokenInfo <> nil then
FreeMem(TokenInfo);
if HaveToken then
CloseHandle(Token);
if psidAdmin <> nil then
FreeSid(psidAdmin);
end;
end;
{$R+}
function IsUACEnabled: Boolean;
var
Reg: TRegistry;
begin
Result := CheckWin32Version(6, 0);
if Result then
begin
Reg := TRegistry.Create(KEY_READ);
try
Reg.RootKey := HKEY_LOCAL_MACHINE;
if Reg.OpenKey('\Software\Microsoft\Windows\CurrentVersion\Policies\System', False) then
if Reg.ValueExists('EnableLUA') then
Result := (Reg.ReadInteger('EnableLUA') <> 0)
else
Result := False
else
Result := False;
finally
FreeAndNil(Reg);
end;
end;
end;
function IsElevated: Boolean;
const
TokenElevation = TTokenInformationClass(20);
type
TOKEN_ELEVATION = record
TokenIsElevated: DWORD;
end;
var
TokenHandle: THandle;
ResultLength: Cardinal;
ATokenElevation: TOKEN_ELEVATION;
HaveToken: Boolean;
begin
if CheckWin32Version(6, 0) then
begin
TokenHandle := 0;
HaveToken := OpenThreadToken(GetCurrentThread, TOKEN_QUERY, True, TokenHandle);
if (not HaveToken) and (GetLastError = ERROR_NO_TOKEN) then
HaveToken := OpenProcessToken(GetCurrentProcess, TOKEN_QUERY, TokenHandle);
if HaveToken then
begin
try
ResultLength := 0;
if GetTokenInformation(TokenHandle, TokenElevation, #ATokenElevation, SizeOf(ATokenElevation), ResultLength) then
Result := ATokenElevation.TokenIsElevated <> 0
else
Result := False;
finally
CloseHandle(TokenHandle);
end;
end
else
Result := False;
end
else
Result := IsAdministrator;
end;
procedure SetButtonElevated(const AButtonHandle: THandle);
const
BCM_SETSHIELD = $160C;
var
Required: BOOL;
begin
if not CheckWin32Version(6, 0) then
Exit;
if IsElevated then
Exit;
Required := True;
SendMessage(AButtonHandle, BCM_SETSHIELD, 0, LPARAM(Required));
end;
procedure CheckForElevatedTask;
function GetArgsForElevatedTask: String;
function PrepareParam(const ParamNo: Integer): String;
begin
Result := ParamStr(ParamNo);
if Pos(' ', Result) > 0 then
Result := AnsiQuotedStr(Result, '"');
end;
var
X: Integer;
begin
Result := '';
for X := 1 to ParamCount do
begin
if (AnsiUpperCase(ParamStr(X)) = ('/' + RunElevatedTaskSwitch)) or
(AnsiUpperCase(ParamStr(X)) = ('-' + RunElevatedTaskSwitch)) then
Continue;
Result := Result + PrepareParam(X) + ' ';
end;
Result := Trim(Result);
end;
var
ExitCode: Cardinal;
begin
if not FindCmdLineSwitch(RunElevatedTaskSwitch) then
Exit;
ExitCode := ERROR_GEN_FAILURE;
try
if not IsElevated then
ExitCode := ERROR_ACCESS_DENIED
else
if Assigned(OnElevateProc) then
ExitCode := OnElevateProc(GetArgsForElevatedTask)
else
ExitCode := ERROR_PROC_NOT_FOUND;
except
on E: Exception do
begin
if E is EAbort then
ExitCode := ERROR_CANCELLED
else
if E is EOleSysError then
ExitCode := Cardinal(EOleSysError(E).ErrorCode)
else
if E is EOSError then
else
ExitCode := ERROR_GEN_FAILURE;
end;
end;
if ExitCode = STILL_ACTIVE then
ExitCode := ERROR_GEN_FAILURE;
TerminateProcess(GetCurrentProcess, ExitCode);
end;
end.
Usage:
unit Unit1;
interface
uses
Windows{....};
type
TForm1 = class(TForm)
Label1: TLabel;
Label2: TLabel;
Label3: TLabel;
Label4: TLabel;
Button1: TButton;
Button2: TButton;
procedure FormCreate(Sender: TObject);
procedure Button1Click(Sender: TObject);
procedure Button2Click(Sender: TObject);
private
procedure StartWait;
procedure EndWait;
end;
var
Form1: TForm1;
implementation
uses
RunElevatedSupport;
{$R *.dfm}
const
ArgInstallUpdate = '/install_update';
ArgRegisterExtension = '/register_global_file_associations';
procedure TForm1.FormCreate(Sender: TObject);
begin
Label1.Caption := Format('IsAdministrator: %s', [BoolToStr(IsAdministrator, True)]);
Label2.Caption := Format('IsAdministratorAccount: %s', [BoolToStr(IsAdministratorAccount, True)]);
Label3.Caption := Format('IsUACEnabled: %s', [BoolToStr(IsUACEnabled, True)]);
Label4.Caption := Format('IsElevated: %s', [BoolToStr(IsElevated, True)]);
Button1.Caption := 'Install updates';
SetButtonElevated(Button1.Handle);
Button2.Caption := 'Register file associations for all users';
SetButtonElevated(Button2.Handle);
end;
procedure TForm1.Button1Click(Sender: TObject);
begin
StartWait;
try
SetLastError(RunElevated(ArgInstallUpdate, Handle, Application.ProcessMessages));
if GetLastError <> ERROR_SUCCESS then
RaiseLastOSError;
finally
EndWait;
end;
end;
procedure TForm1.Button2Click(Sender: TObject);
begin
StartWait;
try
SetLastError(RunElevated(ArgRegisterExtension, Handle, Application.ProcessMessages));
if GetLastError <> ERROR_SUCCESS then
RaiseLastOSError;
finally
EndWait;
end;
end;
function DoElevatedTask(const AParameters: String): Cardinal;
procedure InstallUpdate;
var
Msg: String;
begin
Msg := 'Hello from InstallUpdate!' + sLineBreak +
sLineBreak +
'This function is running elevated under full administrator rights.' + sLineBreak +
'This means that you have write-access to Program Files folder and you''re able to overwrite files (e.g. install updates).' + sLineBreak +
'However, note that your executable is still running.' + sLineBreak +
sLineBreak +
'IsAdministrator: ' + BoolToStr(IsAdministrator, True) + sLineBreak +
'IsAdministratorAccount: ' + BoolToStr(IsAdministratorAccount, True) + sLineBreak +
'IsUACEnabled: ' + BoolToStr(IsUACEnabled, True) + sLineBreak +
'IsElevated: ' + BoolToStr(IsElevated, True);
MessageBox(0, PChar(Msg), 'Hello from InstallUpdate!', MB_OK or MB_ICONINFORMATION);
end;
procedure RegisterExtension;
var
Msg: String;
begin
Msg := 'Hello from RegisterExtension!' + sLineBreak +
sLineBreak +
'This function is running elevated under full administrator rights.' + sLineBreak +
'This means that you have write-access to HKEY_LOCAL_MACHINE key and you''re able to write keys and values (e.g. register file extensions globally/for all users).' + sLineBreak +
'However, note that this is usually not a good idea. It is better to register your file extensions under HKEY_CURRENT_USER\Software\Classes.' + sLineBreak +
sLineBreak +
'IsAdministrator: ' + BoolToStr(IsAdministrator, True) + sLineBreak +
'IsAdministratorAccount: ' + BoolToStr(IsAdministratorAccount, True) + sLineBreak +
'IsUACEnabled: ' + BoolToStr(IsUACEnabled, True) + sLineBreak +
'IsElevated: ' + BoolToStr(IsElevated, True);
MessageBox(0, PChar(Msg), 'Hello from RegisterExtension!', MB_OK or MB_ICONINFORMATION);
end;
begin
Result := ERROR_SUCCESS;
if AParameters = ArgInstallUpdate then
InstallUpdate
else
if AParameters = ArgRegisterExtension then
RegisterExtension
else
Result := ERROR_GEN_FAILURE;
end;
procedure TForm1.StartWait;
begin
Cursor := crHourglass;
Screen.Cursor := crHourglass;
Button1.Enabled := False;
Button2.Enabled := False;
Application.ProcessMessages;
end;
procedure TForm1.EndWait;
begin
Cursor := crDefault;
Screen.Cursor := crDefault;
Button1.Enabled := True;
Button2.Enabled := True;
Application.ProcessMessages;
end;
initialization
OnElevateProc := DoElevatedTask;
CheckForElevatedTask;
end.

Answer 4

uses ShellApi, ...;
function RunAsAdmin(const Handle: Hwnd; const Path, Params: string): Boolean;
var
sei: TShellExecuteInfoA;
begin
FillChar(sei, SizeOf(sei), 0);
sei.cbSize := SizeOf(sei);
sei.Wnd := Handle;
sei.fMask := SEE_MASK_FLAG_DDEWAIT or SEE_MASK_FLAG_NO_UI;
sei.lpVerb := 'runas';
sei.lpFile := PAnsiChar(Path);
sei.lpParameters := PAnsiChar(Params);
sei.nShow := SW_SHOWNORMAL;
Result := ShellExecuteExA(#sei);
end;
// Example
RunAsAdmin(Handle, 'c:\Windows\system32\cmd.exe', '');