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
135
136
137
138
139
140
141
142
143
144
145
146
|
package jwt
import (
"crypto/subtle"
"fmt"
"time"
)
// For a type to be a Claims object, it must just have a Valid method that determines
// if the token is invalid for any supported reason
type Claims interface {
Valid() error
}
// Structured version of Claims Section, as referenced at
// https://tools.ietf.org/html/rfc7519#section-4.1
// See examples for how to use this with your own claim types
type StandardClaims struct {
Audience string `json:"aud,omitempty"`
ExpiresAt int64 `json:"exp,omitempty"`
Id string `json:"jti,omitempty"`
IssuedAt int64 `json:"iat,omitempty"`
Issuer string `json:"iss,omitempty"`
NotBefore int64 `json:"nbf,omitempty"`
Subject string `json:"sub,omitempty"`
}
// Validates time based claims "exp, iat, nbf".
// There is no accounting for clock skew.
// As well, if any of the above claims are not in the token, it will still
// be considered a valid claim.
func (c StandardClaims) Valid() error {
vErr := new(ValidationError)
now := TimeFunc().Unix()
// The claims below are optional, by default, so if they are set to the
// default value in Go, let's not fail the verification for them.
if !c.VerifyExpiresAt(now, false) {
delta := time.Unix(now, 0).Sub(time.Unix(c.ExpiresAt, 0))
vErr.Inner = fmt.Errorf("token is expired by %v", delta)
vErr.Errors |= ValidationErrorExpired
}
if !c.VerifyIssuedAt(now, false) {
vErr.Inner = fmt.Errorf("Token used before issued")
vErr.Errors |= ValidationErrorIssuedAt
}
if !c.VerifyNotBefore(now, false) {
vErr.Inner = fmt.Errorf("token is not valid yet")
vErr.Errors |= ValidationErrorNotValidYet
}
if vErr.valid() {
return nil
}
return vErr
}
// Compares the aud claim against cmp.
// If required is false, this method will return true if the value matches or is unset
func (c *StandardClaims) VerifyAudience(cmp string, req bool) bool {
return verifyAud([]string{c.Audience}, cmp, req)
}
// Compares the exp claim against cmp.
// If required is false, this method will return true if the value matches or is unset
func (c *StandardClaims) VerifyExpiresAt(cmp int64, req bool) bool {
return verifyExp(c.ExpiresAt, cmp, req)
}
// Compares the iat claim against cmp.
// If required is false, this method will return true if the value matches or is unset
func (c *StandardClaims) VerifyIssuedAt(cmp int64, req bool) bool {
return verifyIat(c.IssuedAt, cmp, req)
}
// Compares the iss claim against cmp.
// If required is false, this method will return true if the value matches or is unset
func (c *StandardClaims) VerifyIssuer(cmp string, req bool) bool {
return verifyIss(c.Issuer, cmp, req)
}
// Compares the nbf claim against cmp.
// If required is false, this method will return true if the value matches or is unset
func (c *StandardClaims) VerifyNotBefore(cmp int64, req bool) bool {
return verifyNbf(c.NotBefore, cmp, req)
}
// ----- helpers
func verifyAud(aud []string, cmp string, required bool) bool {
if len(aud) == 0 {
return !required
}
// use a var here to keep constant time compare when looping over a number of claims
result := false
var stringClaims string
for _, a := range aud {
if subtle.ConstantTimeCompare([]byte(a), []byte(cmp)) != 0 {
result = true
}
stringClaims = stringClaims + a
}
// case where "" is sent in one or many aud claims
if len(stringClaims) == 0 {
return !required
}
return result
}
func verifyExp(exp int64, now int64, required bool) bool {
if exp == 0 {
return !required
}
return now <= exp
}
func verifyIat(iat int64, now int64, required bool) bool {
if iat == 0 {
return !required
}
return now >= iat
}
func verifyIss(iss string, cmp string, required bool) bool {
if iss == "" {
return !required
}
if subtle.ConstantTimeCompare([]byte(iss), []byte(cmp)) != 0 {
return true
} else {
return false
}
}
func verifyNbf(nbf int64, now int64, required bool) bool {
if nbf == 0 {
return !required
}
return now >= nbf
}
|
