Lua Requires Chilkat v11.0.0+
Lua
Validate JWS with Multiple Signatures using the General JSON Serialization Format
See more JSON Web Signatures (JWS) Examples
Validates and recovers data and headers from a JSON Web Signature (JWS) containing 3 signatures.Note: Chilkat supports all of the following JWS algorithms:
+--------------+-------------------------------+--------------------+ | "alg" Param | Digital Signature or MAC | Implementation | | Value | Algorithm | Requirements | +--------------+-------------------------------+--------------------+ | HS256 | HMAC using SHA-256 | Required | | HS384 | HMAC using SHA-384 | Optional | | HS512 | HMAC using SHA-512 | Optional | | RS256 | RSASSA-PKCS1-v1_5 using | Recommended | | | SHA-256 | | | RS384 | RSASSA-PKCS1-v1_5 using | Optional | | | SHA-384 | | | RS512 | RSASSA-PKCS1-v1_5 using | Optional | | | SHA-512 | | | ES256 | ECDSA using P-256 and SHA-256 | Recommended+ | | ES384 | ECDSA using P-384 and SHA-384 | Optional | | ES512 | ECDSA using P-521 and SHA-512 | Optional | | PS256 | RSASSA-PSS using SHA-256 and | Optional | | | MGF1 with SHA-256 | | | PS384 | RSASSA-PSS using SHA-384 and | Optional | | | MGF1 with SHA-384 | | | PS512 | RSASSA-PSS using SHA-512 and | Optional | | | MGF1 with SHA-512 | | +--------------+-------------------------------+--------------------+
Chilkat Lua Downloads
local chilkat = require("chilkat")
-- This requires the Chilkat API to have been previously unlocked.
-- See Global Unlock Sample for sample code.
-- First, prepare the public keys that will be needed for each signature.
-- ---------------------------------------------------
-- Use the following RSA key loaded from JWK format.
local sbRsaJwk = chilkat.StringBuilder.new()
sbRsaJwk:append("{\"kty\":\"RSA\",")
sbRsaJwk:append("\"n\":\"ofgWCuLjybRlzo0tZWJjNiuSfb4p4fAkd_wWJcyQoTbji9k0l8W26mPddx")
sbRsaJwk:append("HmfHQp-Vaw-4qPCJrcS2mJPMEzP1Pt0Bm4d4QlL-yRT-SFd2lZS-pCgNMs")
sbRsaJwk:append("D1W_YpRPEwOWvG6b32690r2jZ47soMZo9wGzjb_7OMg0LOL-bSf63kpaSH")
sbRsaJwk:append("SXndS5z5rexMdbBYUsLA9e-KXBdQOS-UTo7WTBEMa2R2CapHg665xsmtdV")
sbRsaJwk:append("MTBQY4uDZlxvb3qCo5ZwKh9kG4LT6_I5IhlJH7aGhyxXFvUK-DWNmoudF8")
sbRsaJwk:append("NAco9_h9iaGNj8q2ethFkMLs91kzk2PAcDTW9gb54h4FRWyuXpoQ\",")
sbRsaJwk:append("\"e\":\"AQAB\"")
sbRsaJwk:append("}")
local rsaKey = chilkat.PublicKey.new()
local success = rsaKey:load_from_string(sbRsaJwk:get_as_string())
if not success then
print(rsaKey.last_error_text)
return
end
-- ---------------------------------------------------
-- Use the following ECC public key loaded from JWK format.
local sbEccJwk = chilkat.StringBuilder.new()
sbEccJwk:append("{\"kty\":\"EC\",")
sbEccJwk:append("\"crv\":\"P-256\",")
sbEccJwk:append("\"x\":\"f83OJ3D2xF1Bg8vub9tLe1gHMzV76e8Tus9uPHvRVEU\",")
sbEccJwk:append("\"y\":\"x_FEzRu9m36HLN_tue659LNpXW6pCyStikYjKIWI5a0\"")
sbEccJwk:append("}")
local eccKey = chilkat.PublicKey.new()
success = eccKey:load_from_string(sbEccJwk:get_as_string())
if not success then
print(eccKey.last_error_text)
return
end
-- ---------------------------------------------------
-- The HMAC key (in base64url format)
local hmacKey = "AyM1SysPpbyDfgZld3umj1qzKObwVMkoqQ-EstJQLr_T-1qS0gZH75aKtMN3Yj0iPS4hcgUuTwjAzZr1Z9CAow"
-- The code below will verify each of the signatures in this JWS:
-- {
-- "payload": "SW4gb3VyIHZpbGxhZ2UsIGZvbGtzIHNheSBHb2QgY3J1bWJsZXMgdXAgdGhlIG9sZCBtb29uIGludG8gc3RhcnMu",
-- "signatures": [
-- {
-- "protected": "eyJhbGciOiJSUzI1NiIsImtpZCI6Im15UnNhS2V5In0",
-- "signature": "IPMQ02niTQDwLzsRZSCaEm9VEyAX_AVe3HWjniNt9kW-a8d6ZVbd2k6jGae8s1yIh0cgxDnXQ6-p6_sBI0cnMO0xpuJANhh2vFtNJl5lisad94-H3mB3lSfafRqxeYp5D8bh39BPv7y3PrUNVMQdKEJp_D5oJ0ROPTIYx3EG8eJQOx1HO0KqhcUo401XR6KSsIyFm5joBLNKTVzxZUTT1RRZZtwTdeZkbGevugIOX_9gHAtARpV6WaFA4Vvjnq8X9wPgqjWNCQRupadhTPz0JAsa-wy5vXQjsFlXAn43mDPpMfna5Ab3F5pS4yDwkbX6nRn7XBxH1SnnNJRFholQZw"
-- },
-- {
-- "protected": "eyJhbGciOiJFUzI1NiIsImtpZCI6Im15RWNLZXkifQ",
-- "signature": "1OQtaT3pgZmkDxvlfghvxL_8kX16WIen6u1MadEq1pA4qytA0--_EwZDNk00GDPWFpoJtKznibMZzLOg_UhHIw"
-- },
-- {
-- "protected": "eyJhbGciOiJIUzI1NiIsImtpZCI6Im15TWFjS2V5In0",
-- "signature": "YY8yVjmJJfy7YJOn3uUydG8WCY2PEuCvOLil5Ks5lnw"
-- }
-- ]
-- }
local sbJws = chilkat.StringBuilder.new()
sbJws:append("{ ")
sbJws:append(" \"payload\": \"SW4gb3VyIHZpbGxhZ2UsIGZvbGtzIHNheSBHb2QgY3J1bWJsZXMgdXAgdGhlIG9sZCBtb29uIGludG8gc3RhcnMu\",")
sbJws:append(" \"signatures\": [")
sbJws:append(" { ")
sbJws:append(" \"protected\": \"eyJhbGciOiJSUzI1NiIsImtpZCI6Im15UnNhS2V5In0\",")
sbJws:append(" \"signature\": \"IPMQ02niTQDwLzsRZSCaEm9VEyAX_AVe3HWjniNt9kW-a8d6ZVbd2k6jGae8s1yIh0cgxDnXQ6-p6_sBI0cnMO0xpuJANhh2vFtNJl5lisad94-H3mB3lSfafRqxeYp5D8bh39BPv7y3PrUNVMQdKEJp_D5oJ0ROPTIYx3EG8eJQOx1HO0KqhcUo401XR6KSsIyFm5joBLNKTVzxZUTT1RRZZtwTdeZkbGevugIOX_9gHAtARpV6WaFA4Vvjnq8X9wPgqjWNCQRupadhTPz0JAsa-wy5vXQjsFlXAn43mDPpMfna5Ab3F5pS4yDwkbX6nRn7XBxH1SnnNJRFholQZw\"")
sbJws:append(" },")
sbJws:append(" { ")
sbJws:append(" \"protected\": \"eyJhbGciOiJFUzI1NiIsImtpZCI6Im15RWNLZXkifQ\",")
sbJws:append(" \"signature\": \"1OQtaT3pgZmkDxvlfghvxL_8kX16WIen6u1MadEq1pA4qytA0--_EwZDNk00GDPWFpoJtKznibMZzLOg_UhHIw\"")
sbJws:append(" },")
sbJws:append(" { ")
sbJws:append(" \"protected\": \"eyJhbGciOiJIUzI1NiIsImtpZCI6Im15TWFjS2V5In0\",")
sbJws:append(" \"signature\": \"YY8yVjmJJfy7YJOn3uUydG8WCY2PEuCvOLil5Ks5lnw\"")
sbJws:append(" }")
sbJws:append(" ]")
sbJws:append("}")
local jws = chilkat.Jws.new()
success = jws:load_jws_sb(sbJws)
if not success then
print(jws.last_error_text)
return
end
-- The payload is easily accessible:
print("Payload: " .. jws:get_payload("utf-8"))
local sbKeyId = chilkat.StringBuilder.new()
local bCaseSensitive = false
local protHeader = chilkat.JsonObject.new()
local numSignatures = jws.num_signatures
local i = 0
while i < numSignatures do
success = jws:get_protected_h(i, protHeader)
if not success then
print(jws.last_error_text)
return
end
print("--------------------------")
print(i .. ": ")
-- Get the protected header.
protHeader.emit_compact = false
print(protHeader:emit())
-- Get the key ID ("kid") member.
-- Note: In this example, the "kid" values are contained in the protected headers.
-- They could've just as easily been located in unprotected headers. In that case,
-- we would've called GetUnprotectedH instead of GetProtectedH(i).
sbKeyId:clear()
sbKeyId:append(protHeader:string_of("kid"))
-- Set the key based on key ID.
if sbKeyId:contents_equal("myRsaKey", bCaseSensitive) then
jws:set_public_key(i, rsaKey)
end
if sbKeyId:contents_equal("myEcKey", bCaseSensitive) then
jws:set_public_key(i, eccKey)
end
if sbKeyId:contents_equal("myMacKey", bCaseSensitive) then
jws:set_mac_key(i, hmacKey, "base64url")
end
-- Validate this signature.
local v = jws:validate(i)
if v < 0 then
-- Perhaps Chilkat was not unlocked or the trial expired..
print("Validate failed for some other reason.")
print(jws.last_error_text)
elseif v == 0 then
print("Invalid signature. The key was incorrect, the JWS was invalid, or both.")
else
print("Signature validated.")
end
i = i + 1
end
-- The output of this program is:
-- Payload: In our village, folks say God crumbles up the old moon into stars.
-- --------------------------
-- 0:
-- {
-- "alg": "RS256",
-- "kid": "myRsaKey"
-- }
--
-- Signature validated.
-- --------------------------
-- 1:
-- {
-- "alg": "ES256",
-- "kid": "myEcKey"
-- }
--
-- Signature validated.
-- --------------------------
-- 2:
-- {
-- "alg": "HS256",
-- "kid": "myMacKey"
-- }
--
-- Signature validated.