Lua Requires Chilkat v11.0.0+

How to Generate a JSON Web Key (JWK)

See more JSON Web Signatures (JWS) Examples

Demonstrates how to generate the following types of JSON Web Keys:

• RSA key pair
• EC key pair
• Octet sequence key (HMAC-256)
• 192-bit AES GCM key

Lua

local chilkat = require("chilkat")

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

-- ----------------------------------------------
-- Generate an RSA key pair in JWK format.
-- (Examples for generating other key types are shown below...)
local rsa = chilkat.Rsa.new()
local rsaKey = chilkat.PrivateKey.new()
local success = rsa:gen_key(2048, rsaKey)
if not success then
    print(rsa.last_error_text)
    return
end

local rsaJwkStr = rsaKey:get_jwk()

-- The string returned is the most compact possible, and therefore it is not
-- very readable.  To pretty-print, load into a JSON object and emit..
local json = chilkat.JsonObject.new()
json.emit_compact = false
json:load(rsaJwkStr)
print(json:emit())

-- Sample RSA JWK:

-- {
--   "kty": "RSA",
--   "n": "6w1Xpof7gKmytJ3yc_yjI5_K3MvVXnBYBDy5Oh2W6Xqu_fOl3W18SjS2AU5xJrTHlB_j84yQjPyXJh_ixjACK4K4dCSYqlLmn3R7QJ84vnHLIEkqwUICqOHdCBjK5xhMrdZxIhuNlJzbARY-3u9RqjsT3HYTjA6JNHUWTYBBRou4gYGm4cJgvX4uexdikqxnze014RmZMaOV_4MR--WL4G8QfNJ2pRBEXQeKyije89H6M5oTSK7KZqFTIqu9hwNtx2oGpGAIcS0Jv5xVl-hDtwXZNwQJaOxMzLw1nwnb2kMliJa67EabQFrQY_xthQNsfzcHJJlpqYiMprW8wRkzmQ",
--   "e": "AQAB",
--   "d": "1_bnXMw-SeYhmxAwb19lqVqtMpdaES5ZwHLmoT4EpbsiQ5T1BfENrMSnoaWoEy8w3Kk8cU7qlY-TdOUBIKWFqOKvhY8GciA_Y6zLfgGNSnYVczGmxfBXr0HvKvxUmWZbNbH9OqBkQnKoSmRdGcp7l1Q2mG4o4ZuNdxRJjKXV0_DTrNLUJzst0hsfoZ6mWUrQcn39XGvvLjz9ySS-DYGI1vli3ayx8jVNuw0rU8UXVs9WmPQLvZO_ZDMhoLEeKsdejnNkUNPAUjqxcSOZRojt4BfCmbt-_1slFb0NsoaqnDVZGezd9J9ocxGuyIWHAJu9GGZEcdaFyiDDs_WA1IS_fQ",
--   "p": "9dU8f6yOklRcpV6ayVMKpyQ6AMuBTF3rZmB498eAvvTkVG1-upm8IkikTVNpPjEalc82Sxuq8oF4N5x1-F33sgVEoCZG-1WFZTn-rnPnXSALES9hqSaVYEwnh61EiY8ckjBVr9jD2nL1JKdbfgVVeo69-9PdjnKYYDVL8eLNPwM",
--   "q": "9MX2sW0GyaOsZ86AYe3eG2ZgcgKHvhJa573gih5Jvi2e-Nv-L0EVK29_DA7n0Pjm-gl9zVAsGsMMkphJyEF9QgyUlJ-59XLqWnECS5gO6WZdtHrJxVvcO-_AOrLIxeYnYcwhmaVaxs_UEpqGzupKHCWgf4cfXe49lrIsqGKH4jM",
--   "dp": "IQgj9uvSxGq9gCL0HXUhC1Bc0tqFZyN_i-QOnQybig0R2R5VVvFtTBYCrbk1fPvQHK0ZGIKBN9CZvK8zUsodjDgU_ofmJcNaBz4BsKM2RVcW5Zo-PyJGFAhnj12CxhEKv8Hq4ZP4zROBSQmLy6Uf1TX05S-Up51SSCshJ0FYXs0",
--   "dq": "RijsMiUfGfL5OvP85pUI4e-xW1yQThHyzpQlZVGTL5jiBVEBhcfw6ndWAj3Pgp2ljyvjTFNboPwhgW93Tpg-8AytFgDGi605sVzNHJ_kPlBiMZY0eYaAFQn-npSaaecziJu7UdAMugneLsruMycCwRij7Ynsmr7sFmLR3B4J9vM",
--   "qi": "jZE-a1pa8YjflpCSH5oqp1f6f6I6-hpZcLdamLCoAcjVSIPk86gtXtOFES4411-DqYzYIZM6B_g_SRYY6JpKAOuZ40mmMTlnIEoVf8BHiGl3g6bBAiN1yQGXrwXJsg2OYnocyRA-xWNdcMSSFA52SwEdar2Mmw29qVzxtC1QbpA"
-- }

-- ----------------------------------------------
-- Generate an EC P-256 key pair in JWK format

local prng = chilkat.Prng.new()
local ecc = chilkat.Ecc.new()
local ecKey = chilkat.PrivateKey.new()
ecc:gen_key("P-256", prng, ecKey)

local ecJwkStr = ecKey:get_jwk()
json:load(ecJwkStr)
print(json:emit())

-- Sample EC JWK Key:
-- {
--   "kty": "EC",
--   "crv": "P-256",
--   "x": "tDeeYABgKEAbWicYPCEEI8sP4SRIhHKcHDW7VqrB4LA",
--   "y": "J08HOoIZ0rX2Me3bNFZUltfxIk1Hrc8FsLu8VaSxsMI",
--   "d": "-bqt1T0wNAN8sP5ruycQZRVlMlt3V_dSwlJ60xAX5io"
-- }

-- ----------------------------------------------
-- Octet sequence keys are intended for representing secret keys, such as HMAC keys and AES keys.

-- We'll use crypt to generate a random UUID..
local crypt = chilkat.Crypt2.new()

-- AES and HMAC keys are simply random arrays of bytes
-- For these, we can just build the JSON directly,
-- with the help of the PRNG object.

local jwkHmac = chilkat.JsonObject.new()
jwkHmac.emit_compact = false

-- Generate a 256-bit HMAK key (32 bytes)
jwkHmac:append_string("kty", "oct")
-- Give the key an optional ID, which can be anything, even strings as simple as "1", "2", etc.
jwkHmac:append_string("kid", crypt:generate_uuid())
-- Indicate the intended key alg (optional)
jwkHmac:append_string("alg", "HS256")
-- Generate the actual key bytes
jwkHmac:append_string("k", prng:gen_random(32, "base64url"))

print(jwkHmac:emit())

-- Sample HMAC-256 JWK:

-- {
--   "kty": "oct",
--   "kid": "06c2515d-41fb-e436-e405-3abb361f5f7a",
--   "alg": "HS256",
--   "k": "wR32w7yiMe5Lhb1vkW2koBpoMxpXTFYuxOYCCIEKjdE"
-- }

-- ----------------------------------------------
-- Now generate a 192-bit (24 byte) key that could be used with AES192GCM

local jwkAes = chilkat.JsonObject.new()
jwkAes.emit_compact = false

jwkAes:append_string("kty", "oct")
jwkAes:append_string("kid", "2")
jwkAes:append_string("k", prng:gen_random(24, "base64url"))

print(jwkAes:emit())

-- Sample AES key:
-- {
--   "kty": "oct",
--   "kid": "2",
--   "k": "akAkq-L_ZTZ6-tEIhDUMtU2ENhsEgL-p"
-- }