When calling GetComputerNameA, the program crash without errors - winapi

I am trying to call GetComputerNameA from AutoIt, this is my code:
Local $mystruct = DllStructCreate(toStr("struct;dword;char[1024];endstruct"))
DllStructSetData($mystruct, 1, 1024)
Local $result = DllCall("kernel32.dll", "int", "GetComputerNameA", "ptr", DllStructGetPtr($mystruct, 2), "ptr", DllStructGetPtr($mystruct, 1))
MsgBox(0, "AutoIt", "Success")
But after I run it, it doesn't print anything, like the script crashed without errors.
Any idea why it failed to call it?

It has two parameters, specifically:
BOOL GetComputerNameA(
LPSTR lpBuffer,
LPDWORD nSize
);
The first is a LPSTR (pointer to a char array), the second is a LPDWORD (pointer to an unsigned int).
Here is how you'd call that:
Func _get_computer_name()
Local $dll_struct = DllStructCreate("char[17]")
$sz = DllStructCreate('int')
Local $x = DllCall("kernel32.dll","int","GetComputerNameA","ptr",DllStructGetPtr($dll_struct),"int_ptr",DllStructGetPtr($sz))
Return DllStructGetData($dll_Struct,1)
EndFunc

Related

From Raku/Perl6, how to read this registry key?

Windows
With Raku/Perl6, how do I use NativeCall to read the value of
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System\ "EnableLUA"]
with RegQueryValueExW?
https://learn.microsoft.com/en-us/windows/win32/api/winreg/nf-winreg-regqueryvalueexw
Many thanks,
-T
edit 12-27-2019 #1: removing bad code and inserting new code
This is how far I have gotten.
Test run string:
K:\Windows\NtUtil>perl6 -I. -e "use WinMount :GetLUA; say GetLUA();"
RegOpenKeyExW
RegOpenKeyExW RtnCode 0
RegQueryValueExW
1
2
RegQueryValueExW RtnCode 87 (87 = ERROR_INVALID_PARAMETER)
lpData pointer 0
lpcbData data length 0
RegCloseKey
RegCloseKey RtnCode 0
True
WinMount.pm6
# unit module WinMount;
# WinMount.pm6#`{
Utilities to mount and dismound drive partitions
Note: LUA must be unset (0x00000000) for mount to function prpoperly
raku -I. -c WinMount.pm6
}
use NativeCall;
use WinPopUps :WinMsg;
# Reference to types and values: http://dsource.org/projects/tango/ticket/820
constant BYTE := uint8;
constant WCHAR := uint16;
constant DWORD := int32;
constant REGSAM := int32;
constant WCHARS := CArray[WCHAR];
constant BYTES := CArray[BYTE];
constant HKEY_CURRENT_USER = 0x80000001;
constant HKEY_LOCAL_MACHINE = 0x80000002;
constant KEY_QUERY_VALUE = 1;
constant ERROR_SUCCESS = 0; # Yeah, I know. The Win-Api uses 0 for success and other values to indicate errors
constant REG_SZ = 1;
constant KEY_READ = 0x20019;
constant KEY_SET_VALUE = 0x0002;
constant REG_DWORD = 0x00000004;
sub to-c-str( Str $str ) returns CArray[WCHAR] is export( :to-c-str ) {
my #str := CArray[WCHAR].new;
for ( $str.comb ).kv -> $i, $char { #str[$i] = $char.ord; }
#str[ $str.chars ] = 0;
#str;
}
sub wstr( Str $str ) returns WCHARS is export( :wstr ) {
CArray[WCHAR].new( $str.comb.map: *.ord )
}
sub GetLUA() is export( :GetLUA ) {
#`{
Returns the LUA value in the registry to True (0x00000001) or False (0x00000000)
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System]
"EnableLUA"=dword:00000000
https://docs.perl6.org/language/nativecall
Win32 return codes:
https://learn.microsoft.com/en-us/windows/win32/debug/system-error-codes--0-499-
}
my Str $SubName = &?ROUTINE.name;
my Str $OS = $*KERNEL.name;
if not $OS eq "win32" { say "Sorry, $SubName only work in Windows."; exit; }
my Bool $LUA = True;
my $RtnCode;
my Str $SubKey = Q[SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System\];
my Str $Key = Q[EnableLUA];
my $lpSubKey = wstr( $SubKey );
my $lpValueName = wstr( $Key );
# my $lpSubKey = CArray[uint8].new($Key.encode.list);
# my $lpValueName = CArray[uint8].new($SubKey.encode.list);
my int32 $Handle;
my int32 $ulOptions = 0;
my int32 $lpData;
my int32 $lpcbData;
my int32 $lpReserved = 1;
#`{
Open the key:
https://learn.microsoft.com/en-us/windows/win32/api/winreg/nf-winreg-regopenkeyexw
https://learn.microsoft.com/en-us/windows/win32/sysinfo/registry-key-security-and-access-rights
C++
LSTATUS RegOpenKeyExW(
HKEY hKey, # Hive name (HKEY_LOCAL_MACHINE)
LPCWSTR lpSubKey, # path to the key(/SOFTWARE/Microsoft/Windows/CurrentVersion/Policies/System/EnableLUA)
DWORD ulOptions, # 0
REGSAM samDesired, # KEY_READ (0x20019), KEY_SET_VALUE (0x0002)
PHKEY phkResult # A pointer to a variable that receives a handle to the opened key
);
}
say "RegOpenKeyExW";
sub RegOpenKeyExW( DWORD, WCHARS, DWORD, DWORD, DWORD is rw) is native("Kernel32.dll") returns DWORD { * };
$RtnCode = RegOpenKeyExW( HKEY_LOCAL_MACHINE, $lpSubKey, $ulOptions, KEY_READ, $Handle );
say "RegOpenKeyExW RtnCode $RtnCode\n";
#`{
Read the key:
use RegQueryValueExW if you know key and value name
https://learn.microsoft.com/en-us/windows/win32/api/winreg/nf-winreg-regqueryvalueexw
C++
LSTATUS RegQueryValueExW(
HKEY hKey, # Hive name (HKEY_LOCAL_MACHINE)
LPCWSTR lpValueName, # path to the key(\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System\EnableLUA)
LPDWORD lpReserved, # give it "int32" without the quotes to give it a NULL
LPDWORD lpType, # Registry Value Type (REG_DWORD which is 32 bit)
LPBYTE lpData, # Pointer to the return value
LPDWORD lpcbData # number of bytes in the return value
);
}
say "RegQueryValueExW";
sub RegQueryValueExW( DWORD, WCHARS, DWORD, DWORD, DWORD is rw, DWORD is rw ) is native("Kernel32.dll") returns DWORD { * };
say "1";
$RtnCode = RegQueryValueExW( $Handle, $lpValueName, $lpReserved, REG_DWORD, $lpData, $lpcbData );
say "2";
say "RegQueryValueExW RtnCode $RtnCode (87 = ERROR_INVALID_PARAMETER)\nlpData pointer $lpData\nlpcbData data length $lpcbData\n";
#`{
Close the key
https://learn.microsoft.com/en-us/windows/win32/api/winreg/nf-winreg-regclosekey
C++
LSTATUS RegCloseKey(
HKEY hKey # handle to the open key to be closed. See RegOpenKeyExW phkResult
);
}
say "RegCloseKey";
sub RegCloseKey( DWORD ) is native("Kernel32.dll") returns DWORD { * };
$RtnCode = RegCloseKey( $Handle );
say "RegCloseKey RtnCode $RtnCode\n";
return $LUA;
}
Here's what I have so far. I am able to successfully retrieve the handle for the registry key, but when I try to read the key it throws "Native call expected argument that references a native integer, but got P6int". And I don't know why yet. But I figured I post this already, maybe someone else can shed some light.
use NativeCall;
constant BYTE := uint8;
constant WCHAR := uint16;
constant DWORD := int32;
constant REGSAM := int32;
constant WCHARS := CArray[WCHAR];
constant BYTES := CArray[BYTE];
constant HKEY_CURRENT_USER = 0x80000001;
constant HKEY_LOCAL_MACHINE = 0x80000002;
constant KEY_QUERY_VALUE = 1;
constant ERROR_SUCCESS = 0; # Yeah, I know. The Win-Api uses 0 for success and other values to indicate errors
constant REG_SZ = 1;
sub RegOpenKeyExW( DWORD, WCHARS, DWORD, REGSAM, DWORD is rw) is native("Kernel32.dll") returns DWORD { * };
#DWORD RegOpenKeyExW(
# HKEY hKey,
# LPCWSTR lpSubKey,
# DWORD ulOptions,
# REGSAM samDesired,
# PHKEY phkResult
#);
sub RegQueryValueExW( DWORD, WCHARS, DWORD is rw, DWORD is rw, BYTE is rw, DWORD is rw) is native("Kernel32.dll") returns DWORD { * };
#DWORD RegQueryValueExW(
# HKEY hKey,
# LPCWSTR lpValueName,
# LPDWORD lpReserved,
# LPDWORD lpType,
# LPBYTE lpData,
# LPDWORD lpcbData
#);
my $key = 'SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System';
my DWORD $hkey;
my $length = 1024;
if RegOpenKeyExW(HKEY_LOCAL_MACHINE, wstr($key), 0, KEY_QUERY_VALUE, $hkey) == ERROR_SUCCESS
{
say "Got handle: $hkey";
my BYTES $buffer = CArray[BYTE].new( 0 xx 1024 );
# throws "Native call expected argument that references a native integer, but got P6int"
if RegQueryValueExW( $hkey, WCHARS, DWORD, REG_SZ, $buffer, $length ) == ERROR_SUCCESS
{
say "Got data of length $length";
say gather for 0 .. $length { take $buffer[$_] };
}
}
sub wstr( Str $str ) returns WCHARS {
CArray[WCHAR].new( $str.comb.map: *.ord )
}

How to get string from pointer

GetWindowThreadProcessId(hwndFoundWindow, &dwTrayProcessID);
HANDLE hTrayProc = OpenProcess(PROCESS_ALL_ACCESS, 0, dwTrayProcessID);
int iButtonsCount = SendMessage(hwndFoundWindow, TB_BUTTONCOUNT, 0, 0);
LPVOID lpData = VirtualAllocEx(hTrayProc, NULL, sizeof(TBBUTTON), MEM_COMMIT, PAGE_READWRITE);
int iButton;
DWORD dwBytesRead;
TBBUTTON buttonData;
dwBytesRead = -1;
int chk_data = (int)SendMessage(hwndFoundWindow, TB_GETBUTTON, iButton, (LPARAM)lpData);
ReadProcessMemory(hTrayProc, lpData, &buttonData, sizeof(TBBUTTON), &dwBytesRead);
int len_text = (int)SendMessage(hwndFoundWindow, TB_GETBUTTONTEXTW, buttonData.idCommand, (LPARAM)lpData);
till now, i know the length of button's text but i also need to get the text to display on console.
my problem is i do not really know how to get that text from the button. please kindly help.
what i am trying is ... trying to access to lpData to get the string inside, but could not do that.
My first comment is that you need to add error checking to your code. As far as I can see, you perform no checking of return values. Any of the API functions you call could fail. If you don't check return values for errors then you have no way of diagnosing where you went wrong.
For instance, starting with GetWindowThreadProcessId, you need to write it like this:
if (GetWindowThreadProcessId(hwndFoundWindow, &dwTrayProcessID) == 0)
{
// handle error
}
And so on for all the other functions. Consult MSDN carefully to understand how each function signals failure.
Now to the main part of the question. I believe that it is the TB_GETBUTTONTEXTW message that is giving you trouble. You need to write it like this:
LRESULT len = SendMessage(hwndFoundWindow, TB_GETBUTTONTEXTW,
buttonData.idCommand, NULL);
if (len == -1)
{
// handle error
}
size_t size = sizeof(wchar_t)*(len+1);
LPVOID lpData = VirtualAllocEx(hTrayProc, NULL, size, MEM_COMMIT, PAGE_READWRITE);
if (lpData == NULL)
{
// handle error
}
len = SendMessage(hwndFoundWindow, TB_GETBUTTONTEXTW,
buttonData.idCommand, (LPARAM)lpData);
if (len == -1)
{
// handle error
}
wchar_t* str = new wchar_t[len+1];
if (!ReadProcessMemory(hTrayProc, lpData, (LPVOID)str, size, NULL))
{
// handle error
}
// the text is now in str, as a null-terminated UTF-16 string
delete[] str;
You need this: (see documentation of TB_GETBUTTONTEXTW).
WCHAR *buffer ;
int len_text = (int)SendMessage(hwndFoundWindow, TB_GETBUTTONTEXTW,
buttonData.idCommand, (LPARAM)NULL);
buffer = (WCHAR*)malloc(sizeof(WCHAR) * (len_text + 1)) ;
SendMessage(hwndFoundWindow, TB_GETBUTTONTEXTW,
buttonData.idCommand, (LPARAM)buffer);
....
free(buffer) ;

Check if thread is alive in Windows

I recently tried to write a code to check if a thread in Windows is alive or not. I searched this forum and found discussions like: How to check if a process or thread is alive or not given their IDs in C++?.
I understand I can use OpenThread API. However it doesn't seem to work in my code as follows.
DWORD WINAPI myThread( LPVOID lpParam )
{
cout<<"child thread"<<endl;
return 0;
}
int main(void)
{
DWORD lTldID = 0;
HANDLE lTldHD = CreateThread(NULL, 0, myThread, 0, 0, &lTldID);
WaitForSingleObject(lTldHD, INFINITE);
HANDLE lHD = OpenThread(0x0040, FALSE, lTldID);
return 1;
}
I expect that the HANDLE lHD should be NULL since the thread 'myThread' should have finished at the time of calling OpenThread(). However, I always got NOT NULL values like 0x00000068. I don't know why this happened. Any idea?
Thanks,
Xiaomo
BOOL WINAPI GetExitCodeThread(
_In_ HANDLE hThread,
_Out_ LPDWORD lpExitCode
);
This function returns immediately. If the specified thread has not terminated and the function succeeds, the status returned is STILL_ACTIVE.

mfc acombo box add string

HKEY hKey = 0;
DWORD dwType = REG_SZ;
TCHAR buf[255] = {0};
DWORD dwBufSize = sizeof(buf);
DWORD ret;
CComboBox m_portCombo;
if( RegOpenKeyEx( HKEY_LOCAL_MACHINE, TEXT("HARDWARE\\DEVICEMAP\\SERIALCOMM"), 0, KEY_QUERY_VALUE, &hKey ) == ERROR_SUCCESS )
{
if( RegQueryValueEx( hKey, TEXT("\\Device\\Serial0"), 0, &dwType, (LPBYTE)buf, &dwBufSize ) == ERROR_SUCCESS )
{
CString str = buf;
m_portCombo.AddString(str);
}
if( RegQueryValueEx( hKey, TEXT("\\Device\\Serial1"), 0, &dwType, (LPBYTE)buf, &dwBufSize ) == ERROR_SUCCESS )
{
CString str = buf;
}
if( RegQueryValueEx( hKey, TEXT("\\Device\\Serial2"), 0, &dwType, (LPBYTE)buf, &dwBufSize ) == ERROR_SUCCESS )
{
CString str = buf;
}
if( RegQueryValueEx( hKey, TEXT("\\Device\\Serial3"), 0, &dwType, (LPBYTE)buf, &dwBufSize ) == ERROR_SUCCESS )
{
CString str = buf;
}
}
First problem: i want to change the TEXT("\\Device\\Serial3") with something like TEXT("\\Device\\Serial",%i), so i can resume all that lines of code to a for loop.Is tehre a way to accomplish this?
Second problem: if i use the m_portCombo.AddString(str); i get an Debug Assertion Failed! error, and, of course, the combobox is not populated with that registry value. Why could that happen?
First Problem: Use the CString Format() function using %d for integer.
for (int i =0 ; i<10; i++)
{
CString szPath;
szPath.Format(TEXT("\\Device\\Serial%d"),i);
// ...
}
Second Problem:
There could be many reasons this would fail. Most likely of which would be having not created the combo box yet.(It needs a window handle before it can add strings) To figure out the cause of the debug assertion, click the "retry" button on the Debug Assertion Failed window and it should jump to the code which caused the assertion. For example it might be something like:
ASSERT(GetSafeHwnd()!=NULL);
Your combo box class won't be 'subclassed' until after the first DoDataExchange is called (and any attempt to use it before that happens will ASSERT). Either wait until the base class has run OnInitDialog or do something like this:
CComboBox * pcombo = static_cast<CComboBox*>(GetDlgItem( IDC_MYCOMBO ));
pcombo->AddString( szPath );
See #TheSteve's answer for string problem.

Can't add my application to autostart

I writing small application in pure C++. But now I encourage strange problem. I wanted to add my application to autostart but it not working. I use this code to access to Registry:
BOOL SetKeyData(HKEY hRootKey, WCHAR *subKey, DWORD dwType, WCHAR *value, LPBYTE data, DWORD cbData)
{
HKEY hKey;
if(RegCreateKeyW(hRootKey, subKey, &hKey) != ERROR_SUCCESS)
return FALSE;
LSTATUS status = RegSetValueExW(hKey, value, 0, dwType, data, cbData);
if(status != ERROR_SUCCESS)
{
RegCloseKey(hKey);
return FALSE;
}
RegCloseKey(hKey);
return TRUE;
}
At first I thought that problem is in data that I serve, so i converted WCHAR with path to LPBYTE like this and execute this function in this way:
size_t i;
char *pMBBuffer = (char *)malloc( MAX_PATH );
wcstombs_s(&i, pMBBuffer, MAX_PATH, my_program, MAX_PATH-1 );
SetKeyData(HKEY_LOCAL_MACHINE, L"Software\\Microsoft\\Windows\\CurrentVersion\\Run", REG_SZ, L"zwApplication", (LPBYTE)pMBBuffer, i))
I get status code ERROR_ACCESS_DENIED. Maybe problem is policy in Windows 7, but I thought that I have full access to everything in HKEY_LOCAL_MACHINE. How to solve this problem?
Writing to HKEY_LOCAL_MACHINE requires that your app runs with elevated privileges. Which means your app would require to set this in its manifest file.
Without this, you can only write to HKEY_CURRENT_USER, or read from HKEY_LOCAL_MACHINE - but for your autostart requirement, that would work just as fine.

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