Lua

AES Encryption

See more Encryption Examples

AES encryption. The Chilkat encryption component supports 128-bit, 192-bit, and 256-bit AES encryption in ECB (Electronic Cookbook), CBC (Cipher-Block Chaining), and other modes. Lua

local chilkat = require("chilkat")

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

local crypt = chilkat.Crypt2.new()

-- AES is also known as Rijndael.
crypt.crypt_algorithm = "aes"

-- CipherMode may be "ecb", "cbc", "ofb", "cfb", "gcm", etc.
-- Note: Check the online reference documentation to see the Chilkat versions
-- when certain cipher modes were introduced.
crypt.cipher_mode = "cbc"

-- KeyLength may be 128, 192, 256
crypt.key_length = 256

-- The padding scheme determines the contents of the bytes
-- that are added to pad the result to a multiple of the
-- encryption algorithm's block size.  AES has a block
-- size of 16 bytes, so encrypted output is always
-- a multiple of 16.
crypt.padding_scheme = 0

-- EncodingMode specifies the encoding of the output for
-- encryption, and the input for decryption.
-- It may be "hex", "url", "base64", or "quoted-printable".
crypt.encoding_mode = "hex"

-- An initialization vector is required if using CBC mode.
-- ECB mode does not use an IV.
-- The length of the IV is equal to the algorithm's block size.
-- It is NOT equal to the length of the key.
local ivHex = "000102030405060708090A0B0C0D0E0F"
crypt:set_encoded_iv(ivHex, "hex")

-- The secret key must equal the size of the key.  For
-- 256-bit encryption, the binary secret key is 32 bytes.
-- For 128-bit encryption, the binary secret key is 16 bytes.
local keyHex = "000102030405060708090A0B0C0D0E0F101112131415161718191A1B1C1D1E1F"
crypt:set_encoded_key(keyHex, "hex")

-- Encrypt a string...
-- The input string is 44 ANSI characters (i.e. 44 bytes), so
-- the output should be 48 bytes (a multiple of 16).
-- Because the output is a hex string, it should
-- be 96 characters long (2 chars per byte).
local encStr = crypt:encrypt_string_enc("The quick brown fox jumps over the lazy dog.")
print(encStr)

-- This is the encrypted output in hex format:
-- 4846F83AA211E239AA62A21F527F089EE9DDBEAD30EE15D4E79B607A621B97BEDB9B6F00A9B21F1B43A50B4C1BE0EDF2

-- Now decrypt:
local decStr = crypt:decrypt_string_enc(encStr)
print(decStr)

-- This is the decrypted string:
-- The quick brown fox jumps over the lazy dog.