go-jwt

This repository contains a JSON Web Tokens library written in Go. The library implements JWT creation, parsing, signing, and verification.

Installation

go get github.com/spiretechnology/go-jwt/v2

Create a JWT

Creating a JWT is simple. The Create(...) function takes two arguments, the claims to include as the payload to the JWT and the Signer to use to sign the JWT. The claims can be any value, as long as that value can be serialized to JSON using json.Marshal. The signed JWT string is returned.

// Create a new JWT token
token, err := jwt.Create(
    myClaims{
        Name: "John Smith",
        Age:  25,
    },
    jwt.HS256Signer([]byte("my secret")),
)

Parsing a JWT

Parsing a JWT from a string into a jwt.Token instance:

// Parse the token
token, err := jwt.Parse(tokenStr)

// Unmarshal the claims
var claims testClaims
err := parsedToken.Claims(&claims)

Verifying a JWT

To verify a parsed token's signature, call token.Verify(...) and provide a verifier corresponding to the signature algorithm you're using.

ok, err := token.Verify(
    jwt.HS256Verifier([]byte("my secret")),
)

An error is returned if something actually goes wrong while verifying the signature. An invalid signature isn't itself an error. When the signature is invalid, but nothing else goes wrong, the return values of the function are (false, nil).

If the signature is valid, the return values are (true, nil).

Signature algorithms

This library implements the following signature algorithms:

Alg	Description
HS256	HMAC SHA256
HS384	HMAC SHA384
HS512	HMAC SHA512
RS256	RSA PKCS1v15 SHA256
RS384	RSA PKCS1v15 SHA384
RS512	RSA PKCS1v15 SHA512
ES256	ECDSA SHA256
ES384	ECDSA SHA384
ES512	ECDSA SHA512
PS256	RSA PSS SHA512
PS384	RSA PSS SHA512
PS512	RSA PSS SHA512