Nginx jwt verification by lua

verify-jwt.lua

local cjson = require "cjson"
local jwt = require "resty.jwt"

local args = ngx.req.get_uri_args()

local token = args.BearerToken

if (args.bearerToken ~= nil) then
  token = args.bearerToken
end

if (token == nil or token == "") then
  local authorization = ngx.req.get_headers()["Authorization"]

  if (authorization ~= nil) then
    token = string.sub(authorization, 8)
  end
end

local jwt_obj = jwt:load_jwt(token)

local f = io.open("/opt/nginx/conf/certs/client_ssl.pem", "rb")
local content = f:read("*all")
f:close()

local verified = jwt:verify_jwt_obj(content, jwt_obj)

if (verified.valid == false) then
  ngx.status = ngx.HTTP_BAD_REQUEST
  ngx.header["Content-Type"] = 'application/json'
  ngx.say(cjson.encode({
    status = ngx.HTTP_BAD_REQUEST,
    message = "Invalid token"
  }))
  ngx.exit(ngx.HTTP_BAD_REQUEST)
elseif (verified.verified == false) then
  ngx.status = ngx.HTTP_UNAUTHORIZED
  ngx.header["Content-Type"] = 'application/json'
  ngx.say(cjson.encode({
    status = ngx.HTTP_UNAUTHORIZED,
    message = "Unauthorized. Token may be expired"
  }))
  ngx.exit(ngx.HTTP_UNAUTHORIZED)
else
  return
end