Sign a JWS with an HMAC Key

See more JSON Web Signatures (JWS) Examples

Demonstrates Jws.SetMacKey, which sets the symmetric MAC key for a signature. The key bytes are supplied in a named encoding such as hex or base64.

local chilkat = require("chilkat")

local jws = chilkat.Jws.new()

-- Protected header specifying HMAC-SHA256.
local header = chilkat.JsonObject.new()
header:update_string("alg", "HS256")
local success = jws:set_protected_header(0, header)
if not success then
    print(jws.last_error_text)
    return
end

local bIncludeBom = false
success = jws:set_payload("This is the content to sign.", "utf-8", bIncludeBom)
if not success then
    print(jws.last_error_text)
    return
end

-- Set the symmetric MAC key for signature 0.  The key bytes are provided in the named encoding (here
-- base64).  In production, obtain the key from a secure source rather than hard-coding it.
local base64Key = "YWJjZGVmZ2hpamtsbW5vcHFyc3R1dnd4eXowMTIzNDU="
success = jws:set_mac_key(0, base64Key, "base64")
if not success then
    print(jws.last_error_text)
    return
end

local jwsCompact = jws:create_jws()
if not jws.last_method_success then
    print(jws.last_error_text)
    return
end

print(jwsCompact)