1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
|
package spectre
import (
"crypto/hmac"
"crypto/sha256"
"golang.org/x/crypto/scrypt"
"strings"
)
// Spectre is a spectre client
type Spectre struct {
name string
secret string
key []byte
scoper Scoper
}
// New returns a Spectre client
func New(name, secret string, opts ...SpectreOption) (s *Spectre, err error) {
s = &Spectre{
name: name,
secret: secret,
scoper: DefaultScoper,
}
for _, opt := range opts {
opt(s)
}
s.key, err = s.userKey()
return
}
// SpectreOption is a Spectre option
type SpectreOption func(*Spectre)
// WithScoper assigns a scoper to Spectre
func WithScoper(scoper Scoper) SpectreOption {
return func(s *Spectre) {
s.scoper = scoper
}
}
func (s *Spectre) userKey() ([]byte, error) {
nameBytes := []byte(s.name)
secretBytes := []byte(s.secret)
keyScope := []byte(s.scoper.Scope(Authentication))
nameBytesLen := len(nameBytes)
keySalt := append(keyScope,
byte(nameBytesLen>>24),
byte(nameBytesLen>>16),
byte(nameBytesLen>>8),
byte(nameBytesLen),
)
keySalt = append(keySalt, nameBytes...)
return scrypt.Key(secretBytes, keySalt, 32768, 8, 2, 64)
}
func (s *Spectre) siteKey(name string, counter int, scope Scope) []byte {
nameBytes := []byte(name)
scopeBytes := []byte(s.scoper.Scope(scope))
nameBytesLen := len(nameBytes)
keySalt := append(scopeBytes,
byte(nameBytesLen>>24),
byte(nameBytesLen>>16),
byte(nameBytesLen>>8),
byte(nameBytesLen),
)
keySalt = append(keySalt, nameBytes...)
keySalt = append(keySalt,
byte(counter>>24),
byte(counter>>16),
byte(counter>>8),
byte(counter),
)
sign := hmac.New(sha256.New, s.key)
sign.Write(keySalt)
return sign.Sum(nil)
}
// Site returns a site password based on Options
func (s *Spectre) Site(siteName string, opts ...SiteOption) string {
siteOpts := &options{
template: Long,
counter: 1,
scope: Authentication,
}
for _, opt := range opts {
opt(siteOpts)
}
siteKey := s.siteKey(siteName, siteOpts.counter, siteOpts.scope)
templateSet := templates[siteOpts.template]
template := templateSet[int(siteKey[0])%len(templateSet)]
var out strings.Builder
for idx, b := range template {
chars := characters[string(b)]
char := chars[int(siteKey[idx+1])%len(chars)]
out.WriteByte(char)
}
return out.String()
}
type options struct {
template Template
counter int
scope Scope
}
type SiteOption func(*options)
func WithTemplate(t Template) SiteOption {
return func(opts *options) {
opts.template = t
}
}
func WithCounter(c int) SiteOption {
return func(opts *options) {
opts.counter = c
}
}
func WithScope(s Scope) SiteOption {
return func(opts *options) {
opts.scope = s
}
}
|