-
Notifications
You must be signed in to change notification settings - Fork 7
/
verifyToken.go
225 lines (194 loc) · 5.11 KB
/
verifyToken.go
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
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
package main
import (
"fmt"
"encoding/json"
"net/http"
"time"
jwt "github.com/dgrijalva/jwt-go"
"crypto/rsa"
"encoding/base64"
"strings"
"errors"
"math/big"
"encoding/binary"
"github.com/joho/godotenv"
"os"
"log"
)
func main() {
loadEnv()
region := os.Getenv("COGNITO_REGION")
userPoolID := os.Getenv("COGNITO_USER_POOL_ID")
tokenString := os.Getenv("COGNITO_TOKEN_STRING")
// 1. Download and store the JSON Web Key (JWK) for your user pool.
jwkURL := fmt.Sprintf("https://cognito-idp.%v.amazonaws.com/%v/.well-known/jwks.json", region, userPoolID)
fmt.Println(jwkURL)
jwk := getJWK(jwkURL)
fmt.Println(jwk)
token, err := validateToken(tokenString, region, userPoolID, jwk)
if err != nil || !token.Valid {
// jwtの検証に失敗
fmt.Printf("token is not valid\n%v", err)
} else {
fmt.Println("success")
}
}
func validateToken(tokenStr, region, userPoolID string, jwk map[string]JWKKey) (*jwt.Token, error) {
// 2. Decode the token string into JWT format.
token, err := jwt.Parse(tokenStr, func(token *jwt.Token) (interface{}, error) {
// cognito user pool : RS256
if _, ok := token.Method.(*jwt.SigningMethodRSA); !ok {
return nil, fmt.Errorf("Unexpected signing method: %v", token.Header["alg"])
}
// 5. Get the kid from the JWT token header and retrieve the corresponding JSON Web Key that was stored
if kid, ok := token.Header["kid"]; ok {
if kidStr, ok := kid.(string); ok {
key := jwk[kidStr]
// 6. Verify the signature of the decoded JWT token.
rsaPublicKey := convertKey(key.E, key.N)
return rsaPublicKey, nil
}
}
// rsa public key取得できず
return "", nil
})
if err != nil {
return token, err
}
claims := token.Claims.(jwt.MapClaims)
iss, ok := claims["iss"]
if !ok {
return token, fmt.Errorf("token does not contain issuer")
}
issStr := iss.(string)
if strings.Contains(issStr, "cognito-idp") {
// 3. 4. 7.のチェックをまとめて
err = validateAWSJwtClaims(claims, region, userPoolID)
if err != nil {
return token, err
}
}
if token.Valid {
return token, nil
}
return token, err
}
// validateAWSJwtClaims validates AWS Cognito User Pool JWT
func validateAWSJwtClaims(claims jwt.MapClaims, region, userPoolID string) error {
var err error
// 3. Check the iss claim. It should match your user pool.
issShoudBe := fmt.Sprintf("https://cognito-idp.%v.amazonaws.com/%v", region, userPoolID)
err = validateClaimItem("iss", []string{issShoudBe}, claims)
if err != nil {
return err
}
// 4. Check the token_use claim.
validateTokenUse := func() error {
if tokenUse, ok := claims["token_use"]; ok {
if tokenUseStr, ok := tokenUse.(string); ok {
if tokenUseStr == "id" || tokenUseStr == "access" {
return nil
}
}
}
return errors.New("token_use should be id or access")
}
err = validateTokenUse()
if err != nil {
return err
}
// 7. Check the exp claim and make sure the token is not expired.
err = validateExpired(claims)
if err != nil {
return err
}
return nil
}
func validateClaimItem(key string, keyShouldBe []string, claims jwt.MapClaims) error {
if val, ok := claims[key]; ok {
if valStr, ok := val.(string); ok {
for _, shouldbe := range keyShouldBe {
if valStr == shouldbe {
return nil
}
}
}
}
return fmt.Errorf("%v does not match any of valid values: %v", key, keyShouldBe)
}
func validateExpired(claims jwt.MapClaims) error {
if tokenExp, ok := claims["exp"]; ok {
if exp, ok := tokenExp.(float64); ok {
now := time.Now().Unix()
fmt.Printf("current unixtime : %v\n", now)
fmt.Printf("expire unixtime : %v\n", int64(exp))
if int64(exp) > now {
return nil
}
}
return errors.New("cannot parse token exp")
}
return errors.New("token is expired")
}
// https://gist.github.com/MathieuMailhos/361f24316d2de29e8d41e808e0071b13
func convertKey(rawE, rawN string) *rsa.PublicKey {
decodedE, err := base64.RawURLEncoding.DecodeString(rawE)
if err != nil {
panic(err)
}
if len(decodedE) < 4 {
ndata := make([]byte, 4)
copy(ndata[4-len(decodedE):], decodedE)
decodedE = ndata
}
pubKey := &rsa.PublicKey{
N: &big.Int{},
E: int(binary.BigEndian.Uint32(decodedE[:])),
}
decodedN, err := base64.RawURLEncoding.DecodeString(rawN)
if err != nil {
panic(err)
}
pubKey.N.SetBytes(decodedN)
// fmt.Println(decodedN)
// fmt.Println(decodedE)
// fmt.Printf("%#v\n", *pubKey)
return pubKey
}
// JWK is json data struct for JSON Web Key
type JWK struct {
Keys []JWKKey
}
// JWKKey is json data struct for cognito jwk key
type JWKKey struct {
Alg string
E string
Kid string
Kty string
N string
Use string
}
func getJWK(jwkURL string) map[string]JWKKey {
jwk := &JWK{}
getJSON(jwkURL, jwk)
jwkMap := make(map[string]JWKKey, 0)
for _, jwk := range jwk.Keys {
jwkMap[jwk.Kid] = jwk
}
return jwkMap
}
func getJSON(url string, target interface{}) error {
var myClient = &http.Client{Timeout: 10 * time.Second}
r, err := myClient.Get(url)
if err != nil {
return err
}
defer r.Body.Close()
return json.NewDecoder(r.Body).Decode(target)
}
func loadEnv() {
err := godotenv.Load(".env")
if err != nil {
log.Fatalf("Error loading %v\n", err)
}
}