ACE_HEADER structure (winnt.h)

The ACE_HEADER structure defines the type and size of an access control entry (ACE).

Syntax

typedef struct _ACE_HEADER {
  BYTE AceType;
  BYTE AceFlags;
  WORD AceSize;
} ACE_HEADER;

Members

AceType

Specifies the ACE type. This member can be one of the following values.

Value Meaning
ACCESS_ALLOWED_ACE_TYPE
Access-allowed ACE that uses the ACCESS_ALLOWED_ACE structure.
ACCESS_ALLOWED_CALLBACK_ACE_TYPE
Access-allowed callback ACE that uses the ACCESS_ALLOWED_CALLBACK_ACE structure.
ACCESS_ALLOWED_CALLBACK_OBJECT_ACE_TYPE
Object-specific access-allowed callback ACE that uses the ACCESS_ALLOWED_CALLBACK_OBJECT_ACE structure.
ACCESS_ALLOWED_COMPOUND_ACE_TYPE
Reserved.
ACCESS_ALLOWED_OBJECT_ACE_TYPE
Object-specific access-allowed ACE that uses the ACCESS_ALLOWED_OBJECT_ACE structure.
ACCESS_DENIED_ACE_TYPE
Access-denied ACE that uses the ACCESS_DENIED_ACE structure.
ACCESS_DENIED_CALLBACK_ACE_TYPE
Access-denied callback ACE that uses the ACCESS_DENIED_CALLBACK_ACE structure.
ACCESS_DENIED_CALLBACK_OBJECT_ACE_TYPE
Object-specific access-denied callback ACE that uses the ACCESS_DENIED_CALLBACK_OBJECT_ACE structure.
ACCESS_DENIED_OBJECT_ACE_TYPE
Object-specific access-denied ACE that uses the ACCESS_DENIED_OBJECT_ACE structure.
ACCESS_MAX_MS_ACE_TYPE
Same as SYSTEM_ALARM_OBJECT_ACE_TYPE.
ACCESS_MAX_MS_V2_ACE_TYPE
Same as SYSTEM_ALARM_ACE_TYPE.
ACCESS_MAX_MS_V3_ACE_TYPE
Reserved.
ACCESS_MAX_MS_V4_ACE_TYPE
Same as SYSTEM_ALARM_OBJECT_ACE_TYPE.
ACCESS_MAX_MS_OBJECT_ACE_TYPE
Same as SYSTEM_ALARM_OBJECT_ACE_TYPE.
ACCESS_MIN_MS_ACE_TYPE
Same as ACCESS_ALLOWED_ACE_TYPE.
ACCESS_MIN_MS_OBJECT_ACE_TYPE
Same as ACCESS_ALLOWED_OBJECT_ACE_TYPE.
SYSTEM_ALARM_ACE_TYPE
Reserved for future use. System-alarm ACE that uses the SYSTEM_ALARM_ACE structure.
SYSTEM_ALARM_CALLBACK_ACE_TYPE
Reserved for future use. System-alarm callback ACE that uses the SYSTEM_ALARM_CALLBACK_ACE structure.
SYSTEM_ALARM_CALLBACK_OBJECT_ACE_TYPE
Reserved for future use. Object-specific system-alarm callback ACE that uses the SYSTEM_ALARM_CALLBACK_OBJECT_ACE structure.
SYSTEM_ALARM_OBJECT_ACE_TYPE
Reserved for future use. Object-specific system-alarm ACE that uses the SYSTEM_ALARM_OBJECT_ACE structure.
SYSTEM_AUDIT_ACE_TYPE
System-audit ACE that uses the SYSTEM_AUDIT_ACE structure.
SYSTEM_AUDIT_CALLBACK_ACE_TYPE
System-audit callback ACE that uses the SYSTEM_AUDIT_CALLBACK_ACE structure.
SYSTEM_AUDIT_CALLBACK_OBJECT_ACE_TYPE
Object-specific system-audit callback ACE that uses the SYSTEM_AUDIT_CALLBACK_OBJECT_ACE structure.
SYSTEM_AUDIT_OBJECT_ACE_TYPE
Object-specific system-audit ACE that uses the SYSTEM_AUDIT_OBJECT_ACE structure.
SYSTEM_MANDATORY_LABEL_ACE_TYPE
0x11
Mandatory label ACE that uses the SYSTEM_MANDATORY_LABEL_ACE structure.

AceFlags

Specifies a set of ACE type-specific control flags. This member can be a combination of the following values.

Value Meaning
CONTAINER_INHERIT_ACE
Child objects that are containers, such as directories, inherit the ACE as an effective ACE. The inherited ACE is inheritable unless the NO_PROPAGATE_INHERIT_ACE bit flag is also set.
FAILED_ACCESS_ACE_FLAG
Used with system-audit ACEs in a system access control list (SACL) to generate audit messages for failed access attempts.
INHERIT_ONLY_ACE
Indicates an inherit-only ACE, which does not control access to the object to which it is attached. If this flag is not set, the ACE is an effective ACE which controls access to the object to which it is attached.

Both effective and inherit-only ACEs can be inherited depending on the state of the other inheritance flags.

INHERITED_ACE
Indicates that the ACE was inherited. The system sets this bit when it propagates an inherited ACE to a child object.
NO_PROPAGATE_INHERIT_ACE
If the ACE is inherited by a child object, the system clears the OBJECT_INHERIT_ACE and CONTAINER_INHERIT_ACE flags in the inherited ACE. This prevents the ACE from being inherited by subsequent generations of objects.
OBJECT_INHERIT_ACE
Noncontainer child objects inherit the ACE as an effective ACE.

For child objects that are containers, the ACE is inherited as an inherit-only ACE unless the NO_PROPAGATE_INHERIT_ACE bit flag is also set.

SUCCESSFUL_ACCESS_ACE_FLAG
Used with system-audit ACEs in a SACL to generate audit messages for successful access attempts.

AceSize

Specifies the size, in bytes, of the ACE.

Remarks

The ACE_HEADER structure is the first member of the various types of ACE structures, such as ACCESS_ALLOWED_ACE.

System-alarm ACEs are not currently supported. The AceType member cannot specify the SYSTEM_ALARM_ACE_TYPE or SYSTEM_ALARM_OBJECT_ACE_TYPE values. Do not use the SYSTEM_ALARM_ACE or SYSTEM_ALARM_OBJECT_ACE structures.

Requirements

Requirement Value
Minimum supported client Windows XP [desktop apps only]
Minimum supported server Windows Server 2003 [desktop apps only]
Header winnt.h (include Windows.h)

See also

ACCESS_ALLOWED_ACE

ACCESS_ALLOWED_OBJECT_ACE

ACCESS_DENIED_ACE

ACCESS_DENIED_OBJECT_ACE

ACL

SYSTEM_AUDIT_ACE

SYSTEM_AUDIT_OBJECT_ACE