Lua Requires Chilkat v9.5.0.84+

Verify JWT with EdDSA / Ed25519 Signature

See more JSON Web Token (JWT) Examples

Demonstrates how to verify a JWT that was signed using an Ed25519 private key.

This example verifies the EdDSA signature. It also does the following:

• Checks to see if the time constraints ("nbf" and "exp") are valid.
• Recovers the original JOSE header.
• Recovers the original data.

Lua

local chilkat = require("chilkat")

-- Demonstrates how to verify a JWT with an EdDSA/Ed25519 Signature

-- This example assumes the Chilkat API to have been previously unlocked.
-- See Global Unlock Sample for sample code.

-- Use this Ed25519 public key for verification

local jsonPubKey = "{\"kty\": \"OKP\",\"alg\": \"EdDSA\",\"crv\": \"Ed25519\",\"x\": \"11qYAYKxCrfVS_7TyWQHOg7hcvPapiMlrwIaaPcHURo\"}"

local pubKey = chilkat.PublicKey.new()
local success = pubKey:load_from_string(jsonPubKey)
if not success then
    print(pubKey.last_error_text)
    return
end

local jwt = chilkat.Jwt.new()
local token = "eyJhbGciOiJFZERTQSJ9.RXhhbXBsZSBvZiBFZDI1NTE5IHNpZ25pbmc.hgyY0il_MGCjP0JzlnLWG1PPOt7-09PGcvMg3AIbQR6dWbhijcNR4ki4iylGjg5BhVsPt9g7sVvpAr_MuM0KAg"

-- First verify the signature.
local sigVerified = jwt:verify_jwt_pk(token, pubKey)
print("verified: " .. tostring(sigVerified))

if not sigVerified then
    print(jwt.last_error_text)
    return
end

-- Let's see if the time constraints, if any, are valid.
-- The above JWT was created on the afternoon of 16-May-2016, with an expiration of 1 hour.
-- If the current system time is before the "nbf" time, or after the "exp" time,
-- then IsTimeValid will return false/0.
-- Also, we'll allow a leeway of 60 seconds to account for any clock skew.
-- Note: If the token has no "nbf" or "exp" claim fields, then IsTimeValid is always true.
local leeway = 60
local bTimeValid = jwt:is_time_valid(token, leeway)
print("time constraints valid: " .. tostring(bTimeValid))

-- Recover the original data (the payload).
local payload = jwt:get_payload(token)
print(payload)

-- Recover the original JOSE header in the same way:
local joseHeader = jwt:get_header(token)
print(joseHeader)