Lua Requires Chilkat v9.5.0.91+

AES XTS Mode

See more Encryption Examples

Demonstrates the AES-XTS mode of operation. Lua

local chilkat = require("chilkat")

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

-- Here we have a sample from CAVS validatition data:

-- COUNT = 301
-- DataUnitLen = 200
-- Key =
-- 394c97881abd989d29c703e48a72b397
-- a7acf51b59649eeea9b33274d8541df4
-- i = 4b15c684a152d485fe9937d39b168c29
-- PT = 2f3b9dcfbae729583b1d1ffdd16bb6fe2757329435662a78f0
-- CT = f3473802e38a3ffef4d4fb8e6aa266ebde553a64528a06463e

-- Note: The above sample requires an AES-XTS implementation that fully supports ciphertext-stealing
-- because the data to be encrypted is not an even multiple of the AES block size (i.e. not a multiple of 16 bytes).
-- Chilkat fully supports AES-XTS with ciphertext stealing.
-- (i.e. Chilkat implements XEX-based tweaked-codebook mode with ciphertext stealing (XTS))

local key = "394c97881abd989d29c703e48a72b397"
local tweakKey = "a7acf51b59649eeea9b33274d8541df4"
local dataUnit = "4b15c684a152d485fe9937d39b168c29"

local bd = chilkat.BinData.new()
bd:append_encoded("2f3b9dcfbae729583b1d1ffdd16bb6fe2757329435662a78f0", "hex")

local crypt = chilkat.Crypt2.new()

crypt.crypt_algorithm = "aes"
crypt.cipher_mode = "xts"
crypt.key_length = 128

crypt:set_encoded_key(key, "hex")
crypt:xts_set_encoded_tweak_key(tweakKey, "hex")
crypt:xts_set_encoded_tweak_value(dataUnit, "hex")

-- In-place encrypt the contents of bd.
local success = crypt:encrypt_bd(bd)

print("CT = " .. bd:get_encoded("hexlower"))

-- Decrypt to revert back to the unencrypted content:
success = crypt:decrypt_bd(bd)

print("PT = " .. bd:get_encoded("hexlower"))

-- Output:
-- CT = f3473802e38a3ffef4d4fb8e6aa266ebde553a64528a06463e
-- PT = 2f3b9dcfbae729583b1d1ffdd16bb6fe2757329435662a78f0