AdjustTokenPrivileges function (securitybaseapi.h)

The AdjustTokenPrivileges function enables or disables privileges in the specified access token. Enabling or disabling privileges in an access token requires TOKEN_ADJUST_PRIVILEGES access.

Syntax

BOOL AdjustTokenPrivileges(
  [in]            HANDLE            TokenHandle,
  [in]            BOOL              DisableAllPrivileges,
  [in, optional]  PTOKEN_PRIVILEGES NewState,
  [in]            DWORD             BufferLength,
  [out, optional] PTOKEN_PRIVILEGES PreviousState,
  [out, optional] PDWORD            ReturnLength
);

Parameters

[in] TokenHandle

A handle to the access token that contains the privileges to be modified. The handle must have TOKEN_ADJUST_PRIVILEGES access to the token. If the PreviousState parameter is not NULL, the handle must also have TOKEN_QUERY access.

[in] DisableAllPrivileges

Specifies whether the function disables all of the token's privileges. If this value is TRUE, the function disables all privileges and ignores the NewState parameter. If it is FALSE, the function modifies privileges based on the information pointed to by the NewState parameter.

[in, optional] NewState

A pointer to a TOKEN_PRIVILEGES structure that specifies an array of privileges and their attributes. If the DisableAllPrivileges parameter is FALSE, the AdjustTokenPrivileges function enables, disables, or removes these privileges for the token. The following table describes the action taken by the AdjustTokenPrivileges function, based on the privilege attribute.

If DisableAllPrivileges is TRUE, the function ignores this parameter.

[in] BufferLength

Specifies the size, in bytes, of the buffer pointed to by the PreviousState parameter. This parameter can be zero if the PreviousState parameter is NULL.

[out, optional] PreviousState

A pointer to a buffer that the function fills with a TOKEN_PRIVILEGES structure that contains the previous state of any privileges that the function modifies. That is, if a privilege has been modified by this function, the privilege and its previous state are contained in the TOKEN_PRIVILEGES structure referenced by PreviousState. If the PrivilegeCount member of TOKEN_PRIVILEGES is zero, then no privileges have been changed by this function. This parameter can be NULL.

If you specify a buffer that is too small to receive the complete list of modified privileges, the function fails and does not adjust any privileges. In this case, the function sets the variable pointed to by the ReturnLength parameter to the number of bytes required to hold the complete list of modified privileges.

[out, optional] ReturnLength

A pointer to a variable that receives the required size, in bytes, of the buffer pointed to by the PreviousState parameter. This parameter can be NULL if PreviousState is NULL.

Return value

If the function succeeds, the return value is nonzero. To determine whether the function adjusted all of the specified privileges, call GetLastError, which returns one of the following values when the function succeeds:

If the function fails, the return value is zero. To get extended error information, call GetLastError.

Remarks

The AdjustTokenPrivileges function cannot add new privileges to the access token. It can only enable or disable the token's existing privileges. To determine the token's privileges, call the GetTokenInformation function.

The NewState parameter can specify privileges that the token does not have, without causing the function to fail. In this case, the function adjusts the privileges that the token does have and ignores the other privileges so that the function succeeds. Call the GetLastError function to determine whether the function adjusted all of the specified privileges. The PreviousState parameter indicates the privileges that were adjusted.

The PreviousState parameter retrieves a TOKEN_PRIVILEGES structure that contains the original state of the adjusted privileges. To restore the original state, pass the PreviousState pointer as the NewState parameter in a subsequent call to the AdjustTokenPrivileges function.

Examples

For an example that uses this function, see Enabling and Disabling Privileges.

Requirements

See also

Access Control Overview

AdjustTokenGroups

Basic Access Control Functions

GetTokenInformation

OpenProcessToken

OpenThreadToken

SetTokenInformation

TOKEN_PRIVILEGES