AdjustTokenPrivileges

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.

BOOL AdjustTokenPrivileges(
  HANDLE TokenHandle,  // handle to token that contains privileges
  BOOL DisableAllPrivileges,
                       // flag for disabling all privileges
  PTOKEN_PRIVILEGES NewState,
                       // pointer to new privilege information
  DWORD BufferLength,  // size, in bytes, of the PreviousState buffer
  PTOKEN_PRIVILEGES PreviousState,
                       // receives original state of changed 
                       // privileges
  PDWORD ReturnLength  // receives required size of the 
                       // PreviousState buffer
);
 

Parameters

TokenHandle

Identifies 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.

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.

NewState

Pointer to a TOKEN_PRIVILEGES structure that specifies an array of privileges and their attributes. If the DisableAllPrivileges parameter is FALSE, AdjustTokenPrivileges enables or disables these privileges for the token. If you set the SE_PRIVILEGE_ENABLED attribute for a privilege, the function enables that privilege; otherwise, it disables the privilege.

If DisableAllPrivileges is TRUE, the function ignores this parameter.

BufferLength

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

PreviousState

Pointer to a buffer that the function fills with a TOKEN_PRIVILEGES structure containing the previous state of any privileges the function modifies. 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.

ReturnLength

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 Values

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.

Note that 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, ignores the other privileges, and returns success. 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 containing the 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

QuickInfo

  Windows NT: Requires version 3.1 or later.
  Windows: Unsupported.
  Windows CE: Unsupported.
  Header: Declared in winbase.h.
  Import Library: Use advapi32.lib.

See Also

Access Control Overview, Access Control Functions, AdjustTokenGroups, GetTokenInformation, OpenProcessToken, OpenThreadToken, SetTokenInformation, TOKEN_PRIVILEGES