How to extract and verify token sent from frontend in golang

golang-jwt-authentication-api-sample
golang authentication
golang authorization middleware
auth0 golang
golang jwt refresh token
golang token
golang rest api basic authentication
gorilla mux jwt

Am using "github.com/dgrijalva/jwt-go", and able to send a token to my frontend, and what I would like to know how I could retrieve the token sent from the frontend so that I can verify if the token that was sent is valid and if so the secured resource will be delivered.

Here is the token sent from frontend JavaScript ...

headers: {
       'Authorization':'Bearer' + localStorage.getItem('id_token')
     }

Here is the code to send token

    token := jwt.New(jwt.GetSigningMethod("HS256"))
    claims := make(jwt.MapClaims)
    claims["userName"] = loginRequest.UserName
    claims["exp"] = time.Now().Add(time.Minute * 60).Unix()
    token.Claims = claims
    tokenString, err := token.SignedString([]byte(SecretKey))
    tokenByte, err := json.Marshal(data)
    w.WriteHeader(201)
    w.Write(tokenByte)

Here is the code to verify the token

    func VerifyToken(r *http.Request) bool {

    reqToken := r.Header.Get("Authorization")
    token, err := jwt.Parse(reqToken, func(t *jwt.Token) (interface{}, error) {
        return []byte(SecretKey), nil
    })
    if err == nil && token.Valid {
        fmt.Println("valid token")
        return true
    } else {
        fmt.Println("invalid token")
        return false
    }

}

Am getting nil token as a return, my guess is i have sent bearer and i think it might need parsing if so how ?


The server requires a token string without added strings in my case I have added Bearer string to the token string in the header when sending request to the web server i.e.

'Authorization':'Bearer' + localStorage.getItem('id_token')

At the web server we need to split only the valid token without the Bearer string

reqToken := r.Header.Get("Authorization")
splitToken := strings.Split(reqToken, "Bearer")
reqToken = splitToken[1]

As a result it becomes valid token without nil.

Authentication in Golang and React using JWTs, , require authentication before handing out a new JWT token. Stack Overflow Public questions and answers; How to extract and verify token sent from frontend in golang. 0. How to verify a JWT Token from AWS Cognito in Go? 0.


The answer above is slightly incorrect because after splitting the reqToken, there should only be one value in splitToken, which is the token itself.

Assuming that the token is of the following format:

'Authorization': 'Bearer <YOUR_TOKEN_HERE>'

Which is the standard format - with a space between the string "Bearer" and the actual token itself.

The following code will perform the correct token extraction:

reqToken := r.Header.Get("Authorization")
splitToken := strings.Split(reqToken, "Bearer")
if len(splitToken) != 2 {
    // Error: Bearer token not in proper format
}

reqToken = strings.TrimSpace(splitToken[1])

fmt.Println(reqToken) // <YOUR_TOKEN_HERE>

JWT authentication: When and how to use it, A JSON Web Token (JWT) is a compact and self-contained way for securely from the backend to the frontend (client), a HttpOnly flag is sent along the to extract the JWT metadata which is used in FetchAuth to check if the  The refresh token is sent by the auth server to the client as an HttpOnly cookie and is automatically sent by the browser in a /refresh_token API call. Because client side Javascript can't read or steal an HttpOnly cookie, this is a little better at mitigating XSS than persisting it as a normal cookie or in localstorage.


Credit: https://github.com/harlow/authtoken/blob/master/authtoken.go

const BEARER_SCHEMA = "Bearer "
authHeader := req.Header.Get("Authorization")
token := authHeader[len(BEARER_SCHEMA):]

Is refreshing an expired JWT token a good strategy?, Learn how to use JSON Web Tokens (JWT) within a Golang If you'd like to use a front-end application to test this API, check out the  jwt.verify (token, secretkey, [options, callback]) The second asynchronous function jwt.verify () will verify the users token when a protected route is accessed. It takes in the token as one


What Happens If Your JWT Is Stolen?, If you just want to see the code check out the application on Github: Golang Secure Now let's add a token.go file to the handlers package: Browsers will do this to try to guess at the content type you are sending. These are primarily for use cases in the front end of an application and thus have not been  Questions tagged [jwt-go] How to extract and verify token sent from frontend in golang. and able to send a token to my frontend, and what I would like to know


Using JWT for Authentication in a Golang Application, If you are new to Go, check out these articles I wrote previously: This is the information which frontend can use Unix() // Generate encoded token and send it as response. We can extract necessary information such as user ID and role from the token to decide whether we want to allow the user access  So you now have users able to sign in on the React side and API authorization implemented on the backend. The final step is to connect the two. The goal here is that a user will sign into the frontend, and then you'll send their token to the backend with the request for product data. If their access token is valid, then you'll return the data.


Authenticate A Golang API With JSON Web Tokens, This token can be used by clients when talking to APIs (by sending it along as an An API that accepts JWTs does an independent verification without depending on framework, you're totally good to go and probably don't need JWTs! what a JWT is, let's create a simple login flow and extract the JWT. Jerem is a golang bot that scrap JIRA project to extract Metrics. Those Metrics can then be send to a Warp 10 Backend. Jerem and Metrics. Jerem was build to send data to the OVH Metrics Data Platform. Copy the config.sample.yml file into a local or edit directly your config.yml. Jerem only require the following valid configuration keys: