Lua

56-bit DES Encryption, ECB, CBC modes

See more Encryption Examples

Demonstrates the older 56-bit DES encryption in ECB and CBC modes. Lua

local chilkat = require("chilkat")

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

local crypt = chilkat.Crypt2.new()

-- Specify DES for the encryption algorithm:
crypt.crypt_algorithm = "des"

-- CipherMode may be "ecb" or "cbc"
crypt.cipher_mode = "cbc"

-- Keylength is 64 bits (56 bits + 8 parity bits)
crypt.key_length = 64

-- 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.  DES has a block
-- size of 8 bytes, so encrypted output is always
-- a multiple of 8.
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 or CFB modes.
-- 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 = "0001020304050607"
crypt:set_encoded_iv(ivHex, "hex")

-- The secret key must equal the size of the key.  For
-- DES, the key must be 8 bytes (i.e. 64-bits).
local keyHex = "0001020304050607"
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 8).
-- 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)

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