Lua Requires Chilkat v11.0.0+

JWE using RSAES-PKCS1-v1_5 and AES_128_CBC_HMAC_SHA_256

See more JSON Web Encryption (JWE) Examples

This example duplicates the example A.2 in RFC 7516 for JSON Web Encryption (JWE). Lua

local chilkat = require("chilkat")

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

local plaintext = "Live long and prosper."

-- First build the JWE Protected Header.
-- We want to build this: {"alg":"RSA1_5","enc":"A128CBC-HS256"}
local jweProtHdr = chilkat.JsonObject.new()
jweProtHdr:append_string("alg", "RSA1_5")
jweProtHdr:append_string("enc", "A128CBC-HS256")
print("JWE Protected Header: " .. jweProtHdr:emit())
print("--")

-- The specific RSA key used in the A.2 example is the following JWK:
local sbJwk = chilkat.StringBuilder.new()
sbJwk:append("{\"kty\":\"RSA\",")
sbJwk:append("\"n\":\"sXchDaQebHnPiGvyDOAT4saGEUetSyo9MKLOoWFsueri23bOdgWp4Dy1Wl")
sbJwk:append("UzewbgBHod5pcM9H95GQRV3JDXboIRROSBigeC5yjU1hGzHHyXss8UDpre")
sbJwk:append("cbAYxknTcQkhslANGRUZmdTOQ5qTRsLAt6BTYuyvVRdhS8exSZEy_c4gs_")
sbJwk:append("7svlJJQ4H9_NxsiIoLwAEk7-Q3UXERGYw_75IDrGA84-lA_-Ct4eTlXHBI")
sbJwk:append("Y2EaV7t7LjJaynVJCpkv4LKjTTAumiGUIuQhrNhZLuF_RJLqHpM2kgWFLU")
sbJwk:append("7-VTdL1VbC2tejvcI2BlMkEpk1BzBZI0KQB0GaDWFLN-aEAw3vRw\",")
sbJwk:append("\"e\":\"AQAB\",")
sbJwk:append("\"d\":\"VFCWOqXr8nvZNyaaJLXdnNPXZKRaWCjkU5Q2egQQpTBMwhprMzWzpR8Sxq")
sbJwk:append("1OPThh_J6MUD8Z35wky9b8eEO0pwNS8xlh1lOFRRBoNqDIKVOku0aZb-ry")
sbJwk:append("nq8cxjDTLZQ6Fz7jSjR1Klop-YKaUHc9GsEofQqYruPhzSA-QgajZGPbE_")
sbJwk:append("0ZaVDJHfyd7UUBUKunFMScbflYAAOYJqVIVwaYR5zWEEceUjNnTNo_CVSj")
sbJwk:append("-VvXLO5VZfCUAVLgW4dpf1SrtZjSt34YLsRarSb127reG_DUwg9Ch-Kyvj")
sbJwk:append("T1SkHgUWRVGcyly7uvVGRSDwsXypdrNinPA4jlhoNdizK2zF2CWQ\",")
sbJwk:append("\"p\":\"9gY2w6I6S6L0juEKsbeDAwpd9WMfgqFoeA9vEyEUuk4kLwBKcoe1x4HG68")
sbJwk:append("ik918hdDSE9vDQSccA3xXHOAFOPJ8R9EeIAbTi1VwBYnbTp87X-xcPWlEP")
sbJwk:append("krdoUKW60tgs1aNd_Nnc9LEVVPMS390zbFxt8TN_biaBgelNgbC95sM\",")
sbJwk:append("\"q\":\"uKlCKvKv_ZJMVcdIs5vVSU_6cPtYI1ljWytExV_skstvRSNi9r66jdd9-y")
sbJwk:append("BhVfuG4shsp2j7rGnIio901RBeHo6TPKWVVykPu1iYhQXw1jIABfw-MVsN")
sbJwk:append("-3bQ76WLdt2SDxsHs7q7zPyUyHXmps7ycZ5c72wGkUwNOjYelmkiNS0\",")
sbJwk:append("\"dp\":\"w0kZbV63cVRvVX6yk3C8cMxo2qCM4Y8nsq1lmMSYhG4EcL6FWbX5h9yuv")
sbJwk:append("ngs4iLEFk6eALoUS4vIWEwcL4txw9LsWH_zKI-hwoReoP77cOdSL4AVcra")
sbJwk:append("Hawlkpyd2TWjE5evgbhWtOxnZee3cXJBkAi64Ik6jZxbvk-RR3pEhnCs\",")
sbJwk:append("\"dq\":\"o_8V14SezckO6CNLKs_btPdFiO9_kC1DsuUTd2LAfIIVeMZ7jn1Gus_Ff")
sbJwk:append("7B7IVx3p5KuBGOVF8L-qifLb6nQnLysgHDh132NDioZkhH7mI7hPG-PYE_")
sbJwk:append("odApKdnqECHWw0J-F0JWnUd6D2B_1TvF9mXA2Qx-iGYn8OVV1Bsmp6qU\",")
sbJwk:append("\"qi\":\"eNho5yRBEBxhGBtQRww9QirZsB66TrfFReG_CcteI1aCneT0ELGhYlRlC")
sbJwk:append("tUkTRclIfuEPmNsNDPbLoLqqCVznFbvdB7x-Tl-m0l_eFTj2KiqwGqE9PZ")
sbJwk:append("B9nNTwMVvH3VRRSLWACvPnSiwP8N5Usy-WRXS-V7TbpxIhvepTfE0NNo\"")
sbJwk:append("}")

-- Load this JWK into a Chilkat private key object.
local rsaPrivKey = chilkat.PrivateKey.new()
local success = rsaPrivKey:load_jwk(sbJwk:get_as_string())
if not success then
    print(rsaPrivKey.last_error_text)
    return
end

-- The public key is used to encrypt (i.e. create the JWE),
-- and the private key is used to decrypt.
-- The RSA public key is simply a subset of the private key.  The RSA public key
-- is composed of the "n" and "e" members shown above.  These are also known as the
-- modulus and exponent.
-- We can simply get the public key object from the private key object
local rsaPubKey = chilkat.PublicKey.new()
rsaPrivKey:to_public_key(rsaPubKey)

-- Create the JWE...
local jwe = chilkat.Jwe.new()
jwe:set_protected_header(jweProtHdr)
jwe:set_public_key(0, rsaPubKey)

local strJwe = jwe:encrypt(plaintext, "utf-8")
if not jwe.last_method_success then
    print(jwe.last_error_text)
    return
end

-- Show the JWE we just created:
print(strJwe)

-- Note: The RSA PKCS1_V1_5 padding uses random value, and the results
-- will be different each time.  However, each result should be successfully
-- decrypting if using the correct RSA private key.

-- Let's decrypt the JWE that was just produced.
-- Do the following to decrypt a JWE:
-- 1) Load the JWE.
-- 2) Set the private key for decryption.
-- 3) Decrypt.
local jwe2 = chilkat.Jwe.new()
success = jwe2:load_jwe(strJwe)
if not success then
    print(jwe2.last_error_text)
    return
end

-- Provide the RSA private key for decryption.
-- (The JWE was encrypted for a single recipient at index 0.)
jwe2:set_private_key(0, rsaPrivKey)

-- Decrypt.
local originalPlaintext = jwe2:decrypt(0, "utf-8")
if not jwe2.last_method_success then
    print(jwe2.last_error_text)
    return
end

print("original text: ")
print(originalPlaintext)

-- ---------------------------------------------------------------------------------
-- It should also be possible to decrypt the JWE as shown in RFC 7516, Appendix A.2.7
-- because it was produced using the same RSA key.

local sbJwe = chilkat.StringBuilder.new()
sbJwe:append("eyJhbGciOiJSU0ExXzUiLCJlbmMiOiJBMTI4Q0JDLUhTMjU2In0.")
sbJwe:append("UGhIOguC7IuEvf_NPVaXsGMoLOmwvc1GyqlIKOK1nN94nHPoltGRhWhw7Zx0-kFm")
sbJwe:append("1NJn8LE9XShH59_i8J0PH5ZZyNfGy2xGdULU7sHNF6Gp2vPLgNZ__deLKxGHZ7Pc")
sbJwe:append("HALUzoOegEI-8E66jX2E4zyJKx-YxzZIItRzC5hlRirb6Y5Cl_p-ko3YvkkysZIF")
sbJwe:append("NPccxRU7qve1WYPxqbb2Yw8kZqa2rMWI5ng8OtvzlV7elprCbuPhcCdZ6XDP0_F8")
sbJwe:append("rkXds2vE4X-ncOIM8hAYHHi29NX0mcKiRaD0-D-ljQTP-cFPgwCp6X-nZZd9OHBv")
sbJwe:append("-B3oWh2TbqmScqXMR4gp_A.")
sbJwe:append("AxY8DCtDaGlsbGljb3RoZQ.")
sbJwe:append("KDlTtXchhZTGufMYmOYGS4HffxPSUrfmqCHXaI9wOGY.")
sbJwe:append("9hH0vgRfYgPnAHOd8stkvw")

success = jwe2:load_jwe_sb(sbJwe)
if not success then
    print(jwe2.last_error_text)
    return
end

-- Provide the RSA private key for decryption.
jwe2:set_private_key(0, rsaPrivKey)

-- Decrypt.
originalPlaintext = jwe2:decrypt(0, "utf-8")
if not jwe2.last_method_success then
    print(jwe2.last_error_text)
    return
end

print(originalPlaintext)