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ZwEnumerateValueKey routine

The ZwEnumerateValueKey routine gets information about the value entries of an open key.

Syntax


NTSTATUS ZwEnumerateValueKey(
  _In_       HANDLE KeyHandle,
  _In_       ULONG Index,
  _In_       KEY_VALUE_INFORMATION_CLASS KeyValueInformationClass,
  _Out_opt_  PVOID KeyValueInformation,
  _In_       ULONG Length,
  _Out_      PULONG ResultLength
);

Parameters

KeyHandle [in]

Handle to the registry key that you want to enumerate value entries for. A successful call to ZwCreateKey or ZwOpenKey creates this handle.

Index [in]

The zero-based index of the subkey that you want value information for.

KeyValueInformationClass [in]

Specifies a KEY_VALUE_INFORMATION_CLASS value that determines the type of information returned in the KeyValueInformation buffer.

KeyValueInformation [out, optional]

Pointer to a caller-allocated buffer that receives the requested information.

Length [in]

Specifies the size, in bytes, of the KeyValueInformation buffer.

ResultLength [out]

Pointer to a variable that receives the size, in bytes, of the value information. If this routine returns STATUS_SUCCESS, the variable indicates the amount of data returned. If this routine returns STATUS_BUFFER_OVERFLOW or STATUS_BUFFER_TOO_SMALL, the variable indicates the buffer size that is required to hold the value information.

Return value

ZwEnumerateValueKey returns STATUS_SUCCESS on success, or the appropriate error code on failure. Possible error code values include:

Return codeDescription
STATUS_BUFFER_OVERFLOW

The buffer supplied is too small, and only partial data has been written to the buffer. *ResultLength is set to the minimum size required to hold the requested information.

STATUS_BUFFER_TOO_SMALL

The buffer supplied is too small, and no data has been written to the buffer. *ResultLength is set to the minimum size required to hold the requested information.

STATUS_INVALID_PARAMETER

The KeyInformationClass parameter is not a valid KEY_VALUE_INFORMATION_CLASS value.

STATUS_NO_MORE_ENTRIES

The Index value is out of range for the registry key specified by KeyHandle. For example, if a key has n subkeys, then for any value greater than n-1 the routine returns STATUS_NO_MORE_ENTRIES.

 

Remarks

The KeyHandle passed to ZwEnumerateValueKey must have been opened with KEY_QUERY_VALUE access. This is accomplished by passing KEY_QUERY_VALUE, KEY_READ, or KEY_ALL_ACCESS as the DesiredAccess parameter to ZwCreateKey or ZwOpenKey.

The Index is simply a way to select among subkeys with value entries. Two calls to ZwEnumerateValueKey with the same Index are not guaranteed to return the same results.

For more information about working with registry keys, see Using the Registry in a Driver.

Note   If the call to this function occurs in user mode, you should use the name "NtEnumerateValueKey" instead of "ZwEnumerateValueKey".

Requirements

Version

Available starting with Windows 2000.

Header

Wdm.h (include Wdm.h, Ntddk.h, or Ntifs.h)

Library

Ntoskrnl.lib

IRQL

PASSIVE_LEVEL

DDI compliance rules

IrqlZwPassive, PowerIrpDDis, ZwRegistryCreate, ZwRegistryOpen, HwStorPortProhibitedDDIs, ZwRegistryCreate(storport), ZwRegistryOpen(storport)

See also

KEY_VALUE_BASIC_INFORMATION
KEY_VALUE_FULL_INFORMATION
KEY_VALUE_PARTIAL_INFORMATION
ZwClose
ZwCreateKey
ZwOpenKey
ZwQueryValueKey

 

 

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