Lua Requires Chilkat v11.0.0+

JWS Using RSASSA-PSS using SHA-256 and MGF1 with SHA-256

See more JSON Web Signatures (JWS) Examples

Creates and validates a JSON Web Signature (JWS) using RSASSA-PSS using SHA-256 and MGF1 with SHA-256.

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             |                    |
   +--------------+-------------------------------+--------------------+

Lua

local chilkat = require("chilkat")

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

-- Use the following RSA key loaded from JWK format.
local sbJwk = chilkat.StringBuilder.new()
sbJwk:append("{\"kty\":\"RSA\",")
sbJwk:append("\"n\":\"ofgWCuLjybRlzo0tZWJjNiuSfb4p4fAkd_wWJcyQoTbji9k0l8W26mPddx")
sbJwk:append("HmfHQp-Vaw-4qPCJrcS2mJPMEzP1Pt0Bm4d4QlL-yRT-SFd2lZS-pCgNMs")
sbJwk:append("D1W_YpRPEwOWvG6b32690r2jZ47soMZo9wGzjb_7OMg0LOL-bSf63kpaSH")
sbJwk:append("SXndS5z5rexMdbBYUsLA9e-KXBdQOS-UTo7WTBEMa2R2CapHg665xsmtdV")
sbJwk:append("MTBQY4uDZlxvb3qCo5ZwKh9kG4LT6_I5IhlJH7aGhyxXFvUK-DWNmoudF8")
sbJwk:append("NAco9_h9iaGNj8q2ethFkMLs91kzk2PAcDTW9gb54h4FRWyuXpoQ\",")
sbJwk:append("\"e\":\"AQAB\",")
sbJwk:append("\"d\":\"Eq5xpGnNCivDflJsRQBXHx1hdR1k6Ulwe2JZD50LpXyWPEAeP88vLNO97I")
sbJwk:append("jlA7_GQ5sLKMgvfTeXZx9SE-7YwVol2NXOoAJe46sui395IW_GO-pWJ1O0")
sbJwk:append("BkTGoVEn2bKVRUCgu-GjBVaYLU6f3l9kJfFNS3E0QbVdxzubSu3Mkqzjkn")
sbJwk:append("439X0M_V51gfpRLI9JYanrC4D4qAdGcopV_0ZHHzQlBjudU2QvXt4ehNYT")
sbJwk:append("CBr6XCLQUShb1juUO1ZdiYoFaFQT5Tw8bGUl_x_jTj3ccPDVZFD9pIuhLh")
sbJwk:append("BOneufuBiB4cS98l2SR_RQyGWSeWjnczT0QU91p1DhOVRuOopznQ\",")
sbJwk:append("\"p\":\"4BzEEOtIpmVdVEZNCqS7baC4crd0pqnRH_5IB3jw3bcxGn6QLvnEtfdUdi")
sbJwk:append("YrqBdss1l58BQ3KhooKeQTa9AB0Hw_Py5PJdTJNPY8cQn7ouZ2KKDcmnPG")
sbJwk:append("BY5t7yLc1QlQ5xHdwW1VhvKn-nXqhJTBgIPgtldC-KDV5z-y2XDwGUc\",")
sbJwk:append("\"q\":\"uQPEfgmVtjL0Uyyx88GZFF1fOunH3-7cepKmtH4pxhtCoHqpWmT8YAmZxa")
sbJwk:append("ewHgHAjLYsp1ZSe7zFYHj7C6ul7TjeLQeZD_YwD66t62wDmpe_HlB-TnBA")
sbJwk:append("-njbglfIsRLtXlnDzQkv5dTltRJ11BKBBypeeF6689rjcJIDEz9RWdc\",")
sbJwk:append("\"dp\":\"BwKfV3Akq5_MFZDFZCnW-wzl-CCo83WoZvnLQwCTeDv8uzluRSnm71I3Q")
sbJwk:append("CLdhrqE2e9YkxvuxdBfpT_PI7Yz-FOKnu1R6HsJeDCjn12Sk3vmAktV2zb")
sbJwk:append("34MCdy7cpdTh_YVr7tss2u6vneTwrA86rZtu5Mbr1C1XsmvkxHQAdYo0\",")
sbJwk:append("\"dq\":\"h_96-mK1R_7glhsum81dZxjTnYynPbZpHziZjeeHcXYsXaaMwkOlODsWa")
sbJwk:append("7I9xXDoRwbKgB719rrmI2oKr6N3Do9U0ajaHF-NKJnwgjMd2w9cjz3_-ky")
sbJwk:append("NlxAr2v4IKhGNpmM5iIgOS1VZnOZ68m6_pbLBSp3nssTdlqvd0tIiTHU\",")
sbJwk:append("\"qi\":\"IYd7DHOhrWvxkwPQsRM2tOgrjbcrfvtQJipd-DlcxyVuuM9sQLdgjVk2o")
sbJwk:append("y26F0EmpScGLq2MowX7fhd_QJQ3ydy5cY7YIBi87w93IKLEdfnbJtoOPLU")
sbJwk:append("W0ITrJReOgo1cq9SbsxYawBgfp_gh6A5603k2-ZQwVK0JKSHuLFkuQ3U\"")
sbJwk:append("}")

local rsaKey = chilkat.PrivateKey.new()
-- Note: This example loads the RSA key from JWK format.  Any format can be loaded
-- into the private key object. (See the online reference documentation..)
local success = rsaKey:load_jwk(sbJwk:get_as_string())
if not success then
    print(rsaKey.last_error_text)
    return
end

-- Create the JWS Protected Header
local jwsProtHdr = chilkat.JsonObject.new()
jwsProtHdr:append_string("alg", "PS256")

local jws = chilkat.Jws.new()

-- Set the protected header:
local signatureIndex = 0
jws:set_protected_header(signatureIndex, jwsProtHdr)

-- Set the RSA key:
jws:set_private_key(signatureIndex, rsaKey)

-- Set the payload.
local bIncludeBom = false
local payloadStr = "In our village, folks say God crumbles up the old moon into stars."
jws:set_payload(payloadStr, "utf-8", bIncludeBom)

-- Create the JWS
-- By default, the compact serialization is used.
local jwsCompact = jws:create_jws()
if not jws.last_method_success then
    print(jws.last_error_text)
    return
end

print("JWS: " .. jwsCompact)

-- Note: RSA PSS padding uses random values, so the output will be different each time a signature is produced.
-- sample output:
-- JWS: eyJhbGciOiJQUzI1NiJ9.SW4gb3VyIHZpbGxhZ2UsIGZvbGtzIHNheSBHb2QgY3J1bWJsZXMgdXAgdGhlIG9sZCBtb29uIGludG8gc3RhcnMu.TRWhwRo5dMv9-8OzrInfJTwmUGYgjLfHk8lqF072ND-FmLWEBnUTOpY8oJXp8FdWw2SalbdOeNlrtlJjwk4XK8Ql2iJ_2qMCtxsvLPhKBOqFoAF4aBvTOEDVJDxf0DaBSiydEEtfTVV2iwBcjWabu5J2XieR5y7QZQtuHsn7T3qKBvCcCejN3Y2oqAT3qMHvu1fTms1r_91wBn_K7Wjd9UkZ1n02qQcUHJznR_OF2BgN7_KWIDAF9ZS9keoju2NPpPelO4yxa2XUPnehY3G7dHKoCxUEQR4d2Xc5voqDASTVCDqQS4PVOZdvT3Ein6-SanAlCwbWBbkvT8g6-5PImQ

-- Now load the JWS, validate, and recover the original text.
local jws2 = chilkat.Jws.new()

-- Load the JWS.
success = jws2:load_jws(jwsCompact)

local rsaPubKey = chilkat.PublicKey.new()
rsaKey:to_public_key(rsaPubKey)

-- Set the RSA public key used for validation.
signatureIndex = 0
jws2:set_public_key(signatureIndex, rsaPubKey)

-- Validate the 1st (and only) signature at index 0..
local v = jws2:validate(signatureIndex)
if v < 0 then
    -- Perhaps Chilkat was not unlocked or the trial expired..
    print("Method call failed for some other reason.")
    print(jws2.last_error_text)
    return
end

if v == 0 then
    print("Invalid signature.  The RSA key was incorrect, the JWS was invalid, or both.")
    return
end

-- If we get here, the signature was validated..
print("Signature validated.")

-- Recover the original content:
print(jws2:get_payload("utf-8"))

-- Examine the protected header:
local joseHeader = chilkat.JsonObject.new()
jws2:get_protected_h(signatureIndex, joseHeader)
joseHeader.emit_compact = false

print("Protected (JOSE) header:")
print(joseHeader:emit())

-- Output:

--     Signature validated.
--     In our village, folks say God crumbles up the old moon into stars.
--     Protected (JOSE) header:
--     {
--       "alg": "PS256"
--     }