Hash a Password with Argon2 (Tuned Options)

Demonstrates Crypt2.Argon2HashPassword with explicit options: the cost parameters, saltLen (how many random salt bytes to generate when no salt is given), and an optional secret (pepper).

local chilkat = require("chilkat")

local crypt = chilkat.Crypt2.new()

-- The password should come from a secure source rather than being hard-coded.
local password = "correct horse battery staple"

-- The Argon2 options are the same members as Argon2DeriveKey, except the salt is optional for
-- hashing.  When no "salt" is given, a random salt is generated; "saltLen" (default 16, range 8..1024)
-- sets how many random bytes to use.
local json = chilkat.JsonObject.new()
json:update_string("variant", "argon2id")
json:update_int("memoryCostKb", 131072)
json:update_int("iterations", 4)
json:update_int("parallelism", 2)
json:update_int("saltLen", 16)

-- A secret (pepper) and/or ad may be used, but neither is stored in the returned PHC string.  The
-- same values must be supplied to Argon2VerifyPassword for the password to verify.
json:update_string("secret", "application-wide-pepper")
json:update_string("secretEncoding", "utf-8")

local phcHash = crypt:argon2_hash_password(password, json:emit())
if not crypt.last_method_success then
    print(crypt.last_error_text)
    return
end

print(phcHash)