ZwCreateKeyTransacted function (wdm.h)

Article
04/18/2022

The ZwCreateKeyTransacted routine creates a new registry key or opens an existing one, and it associates the key with a transaction.

Syntax

NTSYSAPI NTSTATUS ZwCreateKeyTransacted(
  [out]           PHANDLE            KeyHandle,
  [in]            ACCESS_MASK        DesiredAccess,
  [in]            POBJECT_ATTRIBUTES ObjectAttributes,
                  ULONG              TitleIndex,
  [in, optional]  PUNICODE_STRING    Class,
  [in]            ULONG              CreateOptions,
  [in]            HANDLE             TransactionHandle,
  [out, optional] PULONG             Disposition
);

Parameters

[out] KeyHandle

A pointer to a HANDLE variable into which the routine writes the handle to the key.

[in] DesiredAccess

Specifies the type of access to the key that the caller requests. This parameter is an ACCESS_MASK value. For more information, see the description of the DesiredAccess parameter of the ZwCreateKey routine.

[in] ObjectAttributes

A pointer to the object attributes of the key being opened. This parameter points to an OBJECT_ATTRIBUTES structure that must have been previously initialized by the InitializeObjectAttributes routine. The caller must specify the name of the registry key as the ObjectName parameter in the call to InitializeObjectAttributes. If the caller is not running in a system thread context, it must set the OBJ_KERNEL_HANDLE attribute when it calls InitializeObjectAttributes.

TitleIndex

Device and intermediate drivers set this parameter to zero.

[in, optional] Class

Device and intermediate drivers set this parameter to NULL.

[in] CreateOptions

Specifies the options to apply when the routine creates or opens the key. Set this parameter to zero or to the bitwise OR of one or more of the following REG_OPTION_XXX flag bits.

CreateOptions flag	Description
REG_OPTION_VOLATILE	The key is not preserved after the computer restarts.
REG_OPTION_NON_VOLATILE	The key is preserved after the computer restarts.
REG_OPTION_CREATE_LINK	The key is a symbolic link. This flag is not used by device and intermediate drivers.
REG_OPTION_BACKUP_RESTORE	Open the key with special privileges that enable backup and restore operations. This flag is not used by device and intermediate drivers.

[in] TransactionHandle

A handle to a transaction object. To obtain this handle, you can call the ZwCreateTransaction routine. Or, if you have a pointer to a transaction object, you can supply the pointer to the ObOpenObjectByPointer routine to obtain the corresponding transaction handle.

[out, optional] Disposition

A pointer to a location into which the routine writes one of the following values to indicate whether the call created a new key or opened an existing one.

Disposition value	Description
REG_CREATED_NEW_KEY	A new key was created.
REG_OPENED_EXISTING_KEY	An existing key was opened.

You can set Disposition = NULL if this information is not needed.

Return value

ZwCreateKeyTransacted returns STATUS_SUCCESS if the call successfully creates or opens the key. Possible error return values include the following:

Return code	Description
STATUS_INVALID_PARAMETER	The ObjectAttributes parameter is NULL or points to invalid information, or the CreateOptions parameter value specifies invalid options.
STATUS_OBJECT_PATH_SYNTAX_BAD	The registry path in the object attributes is invalid.
STATUS_OBJECT_NAME_NOT_FOUND	The registry path in the object attributes was not found.
STATUS_ACCESS_DENIED	The caller did not have the required access rights to open a handle for the named registry key.
STATUS_INSUFFICIENT_RESOURCES	A memory allocation operation failed.

Remarks

This routine provides a handle that the caller can access a registry key with. Additionally, this routine associates the key with an active transaction.

After the handle that is pointed to by KeyHandle is no longer being used, the driver must call the ZwClose routine to close it.

Like ZwCreateKeyTransacted, the ZwOpenKeyTransacted routine associates a key with a transaction. Unlike ZwCreateKeyTransacted, which can create a new key or open an existing key, ZwOpenKeyTransacted can only open a registry key that already exists.

After a kernel-mode driver obtains a handle to a transaction (for example, by calling ZwCreateTransaction), the driver can perform a series of registry operations that are part of this transaction. The driver can close the transaction either by committing to the changes that were made in the transaction or by rolling back the transaction.

After the driver successfully completes all registry operations that are part of a transaction, it can call the ZwCommitTransaction routine to commit to the changes. The driver can call the ZwRollbackTransaction routine to roll back the transaction.

During a transaction, a registry operation is part of the transaction if the system call that performs the operation meets either of the following conditions:

The call specifies, as an input parameter, the transaction handle. For example, calls to ZwCreateKeyTransacted and ZwOpenKeyTransacted can associate one or more handles to registry keys with the transaction.
The call specifies, as an input parameter, a registry key handle that was obtained by a call to ZwCreateKeyTransacted or ZwOpenKeyTransacted to which the transaction handle was supplied. For example, a call to the ZwSetValueKey routine can use a key handle that was obtained in this way to set the value of a registry key as part of a transaction.

For more information about kernel-mode transactions, see Using Kernel Transaction Manager.

The security descriptor in the object attributes determines whether the access rights that are specified by the DesiredAccess parameter are granted on later calls to routines, such as ZwOpenKeyTransacted that access the key, or to routines, such as ZwCreateKeyTransacted, that create subkeys of the key.

If the kernel-mode caller is not running in a system thread context, it must ensure that any handles it creates are kernel handles. Otherwise, the handle can be accessed by the process in whose context the driver is running. For more information, see Object Handles.

For more information about how to work with registry keys in kernel mode, see Using the Registry in a Driver.

Requirements

Requirement	Value
Minimum supported client	Available in Windows Vista and later versions of Windows.
Target Platform	Universal
Header	wdm.h (include Wdm.h, Ntddk.h, Ntifs.h)
Library	NtosKrnl.lib
DLL	NtosKrnl.exe
IRQL	PASSIVE_LEVEL
DDI compliance rules	HwStorPortProhibitedDDIs(storport), PowerIrpDDis(wdm)