1// Copyright 2016 Google Inc.  All rights reserved.
 2// Use of this source code is governed by a BSD-style
 3// license that can be found in the LICENSE file.
 4
 5package uuid
 6
 7import (
 8	"encoding/binary"
 9	"fmt"
10	"os"
11)
12
13// A Domain represents a Version 2 domain
14type Domain byte
15
16// Domain constants for DCE Security (Version 2) UUIDs.
17const (
18	Person = Domain(0)
19	Group  = Domain(1)
20	Org    = Domain(2)
21)
22
23// NewDCESecurity returns a DCE Security (Version 2) UUID.
24//
25// The domain should be one of Person, Group or Org.
26// On a POSIX system the id should be the users UID for the Person
27// domain and the users GID for the Group.  The meaning of id for
28// the domain Org or on non-POSIX systems is site defined.
29//
30// For a given domain/id pair the same token may be returned for up to
31// 7 minutes and 10 seconds.
32func NewDCESecurity(domain Domain, id uint32) (UUID, error) {
33	uuid, err := NewUUID()
34	if err == nil {
35		uuid[6] = (uuid[6] & 0x0f) | 0x20 // Version 2
36		uuid[9] = byte(domain)
37		binary.BigEndian.PutUint32(uuid[0:], id)
38	}
39	return uuid, err
40}
41
42// NewDCEPerson returns a DCE Security (Version 2) UUID in the person
43// domain with the id returned by os.Getuid.
44//
45//  NewDCESecurity(Person, uint32(os.Getuid()))
46func NewDCEPerson() (UUID, error) {
47	return NewDCESecurity(Person, uint32(os.Getuid()))
48}
49
50// NewDCEGroup returns a DCE Security (Version 2) UUID in the group
51// domain with the id returned by os.Getgid.
52//
53//  NewDCESecurity(Group, uint32(os.Getgid()))
54func NewDCEGroup() (UUID, error) {
55	return NewDCESecurity(Group, uint32(os.Getgid()))
56}
57
58// Domain returns the domain for a Version 2 UUID.  Domains are only defined
59// for Version 2 UUIDs.
60func (uuid UUID) Domain() Domain {
61	return Domain(uuid[9])
62}
63
64// ID returns the id for a Version 2 UUID. IDs are only defined for Version 2
65// UUIDs.
66func (uuid UUID) ID() uint32 {
67	return binary.BigEndian.Uint32(uuid[0:4])
68}
69
70func (d Domain) String() string {
71	switch d {
72	case Person:
73		return "Person"
74	case Group:
75		return "Group"
76	case Org:
77		return "Org"
78	}
79	return fmt.Sprintf("Domain%d", int(d))
80}