jwk.go

Package jwk offer useful functions to handle, fetch and cache JWT public keys from a public JSON Web Key store (IETF RFC 7517, see: https://tools.ietf.org/html/rfc7517)

This package does not currently support the whole standard, but just the slim subset needed for working with the Auth0 Json Web Key Stores: https://auth0.com/docs/jwks

Example

package main

import (
 "fmt"
 "log"

 "github.com/serjlee/jwk.go"
 "github.com/go-jose/go-jose/v3/jwt"
)

 func main() {
  token := "your.jwt.token"
  t, err := jwt.ParseSigned(token)
  if err != nil {
   log.Fatal(err)
  }
  keys := jwk.JSONWebKeys{
   JWKURL: "https://{your-auth0-domain}/.well-known/jwks.json",
  }
  key, err := keys.GetKey(t.Headers[0].KeyID)
  if err != nil {
   log.Fatal(err)
  }
  // that's your public key
  fmt.Println(string(key))
  // you can use an helper function to get it with PEM headers
  fmt.Println(key.PEM())
 }