Validate a JWS Signature

See more JSON Web Signatures (JWS) Examples

Demonstrates Jws.Validate, which validates exactly one signature, identified by a zero-based index, using the key configured at that same index.

local chilkat = require("chilkat")

local jws = chilkat.Jws.new()

-- Load the JWS compact serialization.
local jwsCompact = "eyJhbGciOiJIUzI1NiJ9.VGhpcyBpcyB0aGUgY29udGVudCB0byBzaWduLg.<signature>"
local success = jws:load_jws(jwsCompact)
if not success then
    print(jws.last_error_text)
    return
end

-- Provide the key for signature 0 (here an HMAC key).
local base64Key = "YWJjZGVmZ2hpamtsbW5vcHFyc3R1dnd4eXowMTIzNDU="
success = jws:set_mac_key(0, base64Key, "base64")
if not success then
    print(jws.last_error_text)
    return
end

-- Validate the signature identified by the zero-based index, using the key configured at that index.
-- Validate returns 1 when the signature or MAC is cryptographically valid, 0 when it is not, or a
-- negative value on error.
local v = jws:validate(0)
if v < 0 then
    print(jws.last_error_text)
    return
end

if v ~= 1 then
    print(jws.last_error_text)
    print("The signature is not valid.")
    return
end

print("The signature is valid.")