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 5 package uuid
6 7 import (
8 "encoding/binary"
9 "fmt"
10 "os"
11 )
12 13 // A Domain represents a Version 2 domain
14 type Domain byte
15 16 // Domain constants for DCE Security (Version 2) UUIDs.
17 const (
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.
32 func 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()))
46 func 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()))
54 func 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.
60 func (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.
66 func (uuid UUID) ID() uint32 {
67 return binary.BigEndian.Uint32(uuid[0:4])
68 }
69 70 func (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 }
81