NSIS Header RegOps2

Two registry functions. First is a RegKeyExists function that will determine if a reg key exists without using the Registry plugin. The next one builds on that function, and can use SetACL to reset permissions on a key to allow you to delete it, ie the Enum\Root\LEGACY_ keys.

Should be self-explanatory how to use them. They use the same format as the Registry plugin, ie a full key path.

Release Notes:

Update 2008-04-06

/**************************************************************
*	Copyright Erik Pilsits 2008
***************************************************************
*	${RegKeyExists} "[full key path]" $var
*	
*	$var		0 - key does not exist
*			1 - key exists
***************************************************************
*	Var setacl
*	StrCpy $setacl "X:\path\to\SetACL.exe"
*
*	${SetACL_DeleteKey} "[full key path]" $var1 $var2
*	
*	$var1		[number] - nsExec return code
*			"fail" - operation failed (key does not exist)
*	$var2		0 - delete succeeded
*			non-zero | "fail" - delete failed
***************************************************************
*	LONG WINAPI RegOpenKeyEx(
*	__in        HKEY hKey,
*	__in_opt    LPCTSTR lpSubKey,
*	__reserved  DWORD ulOptions,
*	__in        REGSAM samDesired,
*	__out       PHKEY phkResult
*	);
*
*	LONG WINAPI RegCloseKey(
*	__in  HKEY hKey
*	);
*
*	LSTATUS SHDeleteKey(
*	__in  HKEY hkey,
*	__in  LPCTSTR pszSubKey
*	);
***************************************************************/

!include LogicLib.nsh
!include WordFunc.nsh
!insertmacro WordFind

!define KEY_ALL_ACCESS "0xF003F"
!define KEY_CREATE_SUB_KEY "0x0004"
!define KEY_ENUMERATE_SUB_KEYS "0x0008"
!define KEY_QUERY_VALUE "0x0001"
!define KEY_READ "0x20019"
!define KEY_SET_VALUE "0x0002"
!define KEY_WRITE "0x20006"

!define HKCR "0x80000000"
!define HKCU "0x80000001"
!define HKLM "0x80000002"
!define HKU "0x80000003"
!define HKPD "0x80000004"
!define HKCC "0x80000005"
!define HKDD "0x80000006"

!define RegKeyExists "!insertmacro _RegKeyExists"
!define SetACL_DeleteKey "!insertmacro _SetACL_DeleteKey"

Function SplitKeyPath
	Exch $0 ; save $0, Pop keypath
	Push $1
	
	${WordFind} $0 "\" "+1" $1 ; key root
	Push $1
	Exch 2
	${WordFind} $0 "\" "+1}" $1 ; subkey
	
	Pop $0 ; put root key and subkey on stack
	Exch $1
FunctionEnd

Function GetRootHandle
	Exch $0 ; save $0, Pop root key
	
	${Select} $0
		${Case2} "HKCR" "HKEY_CLASSES_ROOT"
			StrCpy $0 ${HKCR}
		${Case2} "HKCU" "HKEY_CURRENT_USER"
			StrCpy $0 ${HKCU}
		${Case2} "HKLM" "HKEY_LOCAL_MACHINE"
			StrCpy $0 ${HKLM}
		${Case2} "HKU" "HKEY_USERS"
			StrCpy $0 ${HKU}
		${Case2} "HKPD" "HKEY_PERFORMANCE_DATA"
			StrCpy $0 ${HKPD}
		${Case2} "HKCC" "HKEY_CURRENT_CONFIG"
			StrCpy $0 ${HKCC}
		${Case2} "HKDD" "HKEY_DYN_DATA"
			StrCpy $0 ${HKDD}
	${EndSelect}
	
	Exch $0 ; put handle on stack
FunctionEnd

!macro _RegKeyExists keypath outVar
	Push $0
	Push $1
	
	Push "${keypath}"
	Call SplitKeyPath
	Pop $1 ; subkey
	; stack already has root key
	Call GetRootHandle
	Pop $0 ; root key handle
	
	; try to open key
	System::Call /NOUNLOAD 'Advapi32::RegOpenKeyEx(i r0, t r1, i 0, i ${KEY_READ}, *i .r1) i .r0'
	
	; return values
	${If} $0 = 0 ; success
		Push 1
		System::Call 'Advapi32::RegCloseKey(i r1)' ; close handle
	${Else}
		Push 0
		System::Free 0 ; unload system dll
	${EndIf}
		
	Exch 2
	Pop $0
	Pop $1
	Pop ${outVar}
!macroend

!macro _SetACL_DeleteKey keypath outVar1 outVar2
	Push $0
	Push $1
	
	${RegKeyExists} "${keypath}" $0
	${If} $0 = 1
		; set permissions on key
		nsExec::Exec '"$setacl" -on "${keypath}" -ot reg -rec yes \
								-actn clear -clr "dacl" \
								-actn setowner -ownr "n:Administrators" \
								-actn ace -ace "n:Everyone;p:full"'
		Push "${keypath}"
		Call SplitKeyPath
		Pop $1 ; subkey
		; stack already has root key
		Call GetRootHandle
		Pop $0 ; root key handle
		
		; delete key
		System::Call 'shlwapi::SHDeleteKey(i r0, t r1)i .s'
	${Else}
		Push "fail"
		Push "fail"
	${EndIf}
	
	Exch 3
	Pop $0
	Exch
	Pop $1
	Pop ${outVar1}
	Pop ${outVar2}
!macroend