Lua Requires Chilkat v11.6.0+

Hash a Password with Argon2 (Defaults)

Demonstrates Crypt2.Argon2HashPassword, which hashes a password with Argon2 and returns a PHC-format string. Passing an empty options string uses all defaults, including a random salt.

Background. Argon2 (RFC 9106) is a memory-hard function that is deliberately expensive in CPU time and memory, which is what makes brute-forcing the password space costly. The argon2id variant is recommended unless there is a specific reason to choose argon2i or argon2d. The returned PHC string records the variant, version, cost parameters, salt, and hash — everything needed to verify the password later. Store the whole string.

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Lua

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"

-- Hash the password using all defaults by passing an empty options string.  The defaults are
-- Argon2id, version 19, 3 iterations, 64 MB of memory, 1 lane, a 32-byte hash, and a 16-byte random
-- salt.  A random salt is generated automatically, which is what should normally happen.
local phcHash = crypt:argon2_hash_password(password, "")
if not crypt.last_method_success then
    print(crypt.last_error_text)
    return
end

-- The returned PHC-format string records the variant, version, cost parameters, salt, and hash --
-- everything needed to verify the password later.  Store the whole string.
print(phcHash)