Invalid Json web token in Go - json

Question

I am trying to make a Json web token authentication system with Go however I cant seem to get the parsing of the web token working.
The error occurs in the following function.
func RequireTokenAuthentication(rw http.ResponseWriter, req *http.Request, next http.HandlerFunc) {
authBackend := InitJWTAuthenticationBackend()
jwtString := req.Header.Get("Authorization")
token, err := jwt.Parse(jwtString, func(token *jwt.Token) (interface{}, error) {
if _, ok := token.Method.(*jwt.SigningMethodRSA); !ok {
log.Println("Unexpected signing method")
return nil, fmt.Errorf("Unexpected signing method: %v", token.Header["alg"])
} else {
log.Println("The token has been successfully returned")
return authBackend.PublicKey, nil
}
})
log.Println(token)
log.Println(token.Valid)
if err == nil && token.Valid && !authBackend.IsInBlacklist(req.Header.Get("Authorization")) {
next(rw, req)
} else {
rw.WriteHeader(http.StatusUnauthorized)
log.P
rintln("Status unauthorized RequireTokenAuthentication")
}
}
returns the following log
[negroni] Started GET /test/hello
2016/09/13 01:34:46 &{Bearer eyJhbGciOiJSUzUxMiIsInR5cCI6IkpXVCJ9.eyJleHAiOjE0NzM5NzQ4OTAsImlhdCI6MTQ3MzcxNTY5MCwic3ViIjoiIn0.mnwEwdR8nuvdLo_4Ie43me7iph2LeSj1uikokgD6VJB7isjFPShN8E7eQr4GKwuIiLTi34_i6iJRpmx9qrPugkzvsoxX44qlFi6M7FDhVySRiYbBQwTCvKCpvhnsK8BHJyEgy813aaxOMK6sKZJoaKs5JYUvnNZdNqmENYj1BM6FdbGP-oLHuR_CJK0Pym1NMhv9zLI1rpJOGu4mfj1t4tHYZAEGirPnzYMamtrK6TyEFE6Xi4voEEadq7hXvWREg6wNSQsYgww8uOaIWLy1yLbhTkPmT8zfRwLLYLqS_UuZ0xIaSWO1mF2plvOzz1WlF3ZEHLS31T1egB1XL4WTNQe <nil> map[] <nil> false}
2016/09/13 01:34:46 false
2016/09/13 01:34:46 Status unauthorized RequireTokenAuthentication
[negroni] Completed 401 Unauthorized in 71.628ms
and here is the cURL that I am using to initiate it
curl -H "Authorization: Bearer eyJhbGciOiJSUzUxMiIsInR5cCI6IkpXVCJ9.eyJleHAiOjE0NzM5NzQ4OTAsImlhdCI6MTQ3MzcxNTY5MCwic3ViIjoiIn0.mnwEwdR8nuvdLo_4Ie43me7iph2LeSj1uikokgD6VJB7isjFPShN8E7eQr4GKwuIiLTi34_i6iJRpmx9qrPugkzvsoxX44qlFi6M7FDhVySRiYbBQwTCvKCpvhnsK8BHJyEgy813aaxOMK6sKZJoaKs5JYUvnNZdNqmENYj1BM6FdbGP-oLHuR_CJK0Pym1NMhv9zLI1rpJOGu4mfj1t4tHYZAEGirPnzYMamtrK6TyEFE6Xi4voEEadq7hXvWREg6wNSQsYgww8uOaIWLy1yLbhTkPmT8zfRwLLYLqS_UuZ0xIaSWO1mF2plvOzz1WlF3ZEHLS31T1egB1XL4WTNQe" http://localhost:5000/test/hello
I have also tried curl without Bearer
curl -H "Authorization:eyJhbGciOiJSUzUxMiIsInR5cCI6IkpXVCJ9.eyJleHAiOjE0NzM5NzQ4OTAsImlhdCI6MTQ3MzcxNTY5MCwic3ViIjoiIn0.mnwEwdR8nuvdLo_4Ie43me7iph2LeSj1uikokgD6VJB7isjFPShN8E7eQr4GKwuIiLTi34_i6iJRpmx9qrPugkzvsoxX44qlFi6M7FDhVySRiYbBQwTCvKCpvhnsK8BHJyEgy813aaxOMK6sKZJoaKs5JYUvnNZdNqmENYj1BM6FdbGP-oLHuR_CJK0Pym1NMhv9zLI1rpJOGu4mfj1t4tHYZAEGirPnzYMamtrK6TyEFE6Xi4voEEadq7hXvWREg6wNSQsYgww8uOaIWLy1yLbhTkPmT8zfRwLLYLqS_UuZ0xIaSWO1mF2plvOzz1WlF3ZEHLS31T1egB1XL4WTNQe" http://localhost:5000/test/hello
The error is occurring because the token is invalid token.Valid = false I have generated it using the following process.
Here is the router
router.HandleFunc("/token-auth", controllers.Login).Methods("POST")
Here is the login controller
func Login(w http.ResponseWriter, r *http.Request) {
requestUser := new(models.User)
decoder := json.NewDecoder(r.Body)
decoder.Decode(&requestUser)
responseStatus, token := utils.Login(requestUser) //here the util file seen below is used
w.Header().Set("Content-Type", "application/json")
w.WriteHeader(responseStatus)
w.Write(token)
}
This is the util file
func Login(requestUser *models.User) (int, []byte) {
authBackend := authentication.InitJWTAuthenticationBackend()
if authBackend.Authenticate(requestUser) {
token, err := authBackend.GenerateToken(requestUser.UUID)
if err != nil {
return http.StatusInternalServerError, []byte("")
} else {
response, _ := json.Marshal(parameters.TokenAuthentication{token})
return http.StatusOK, response
}
}
return http.StatusUnauthorized, []byte("")
}
and here is the method used to generate the token
func (backend *JWTAuthenticationBackend) GenerateToken(userUUID string) (string, error) {
token := jwt.New(jwt.SigningMethodRS512)
claims := token.Claims.(jwt.MapClaims)
claims["exp"] = time.Now().Add(time.Hour * time.Duration(settings.Get().JWTExpirationDelta)).Unix()
claims["iat"] = time.Now().Unix()
claims["sub"] = userUUID
tokenString, err := token.SignedString(backend.privateKey)
if err != nil {
panic(err)
return "", err
}
return tokenString, nil
}
How do I fix the Token Parsing system so that the token is valid?
If you need any additional information I would be more than happy to make an edit with the respective information.
Thank

Answer 1

The error returned by jwt.Parse() says
tokenstring should not contain 'bearer '
So if you remove "Bearer ":
jwtString = strings.Split(jwtString, "Bearer ")[1]
you get a bit further
The token has been successfully returned
however now there's a new error:
key is of invalid type
Sorry it's not a complete answer!

Answer 2

key is of invalid type
type in this context is referring to the dynamic data-type in Go.
For SigningMethodRSA, the public key must be of type *rsa.PublicKey which can be constructed by calling jwt.ParseRSAPublicKeyFromPEM().
The key value returned to the parser might be created with something like:
keyStruct, _ := jwt.ParseRSAPublicKeyFromPEM(myPublicKeyString)
See:
https://github.com/dgrijalva/jwt-go#signing-methods-and-key-types
https://godoc.org/github.com/dgrijalva/jwt-go#SigningMethodRSA
https://godoc.org/github.com/dgrijalva/jwt-go#ParseRSAPublicKeyFromPEM
Related:
How to generate JWT token always through invalid key type error