key2.lua

local resty_rsa = require "resty.rsa"
local codec          = require "kong.openid-connect.codec"
local base64url = codec.base64url

local algorithm = "SHA256"

ngx.say('---')
-- substitute your "key" here
local k = "MHwwDQYJKoZIhvcNAQEBBQADawAwaAJhANGkBcOBvBWEzSfRYErqBpQByj0LMiV6+CTr274ZHlT7rlegHx2AxGK7l2hpl6Da8tJf1sQmHFq7T8bdrR12zB8TvXcLpkkbK6tVverJh+bGqbSqjDZPoRuhvZdpDb6ziQIDAQAB"
local orig_rsa_public_key = "-----BEGIN PUBLIC KEY-----\n" .. k .. "\n-----END PUBLIC KEY-----"
ngx.say(orig_rsa_public_key)
local pub, err = resty_rsa:new({ public_key = orig_rsa_public_key, key_type = resty_rsa.KEY_TYPE.PKCS8, algorithm = algorithm })
if not pub then
    ngx.say("new rsa err: ", err)
    return
end
-- JWT token = "header.payload.signature"
-- Add your signature part of the JWT here
local sig = "BzdEm_aiFbA6k-VXoAg8wCjJ009UMg3NilywfyyyhnwCmfggZPQIdiNBqm6hXBxlG4jTpn0fEnhDOb2Mo1OKIKMygFxZP_Rm_gaEsqvi7B_G7Vel7wcaCx2z82HDxttq"

-- This is your "header.payload" part of the JWT
local str = "eyJ0eXAiOiJKV1QiLCJhbGciOiJSUzI1NiIsImtpZCI6IjIzMDQ5ODE1MWMyMTRiNzg4ZGQ5N2YyMmI4NTQxMGE1In0.eyJzb21lIjoicGF5bG9hZCJ9"
local  s, err = base64url.decode(sig)
if not s then
 ngx.say("rs signature could not be base64 decoded", err)
end

local verify, err = pub:verify(str, s)
if not verify then
  ngx.say("verify err: ", err)
  return
end
ngx.say(verify)