@eryx/crypto/des Module

JSON

Triple-DES (3DES / TDEA) symmetric encryption.

Only Triple-DES is provided; single DES is cryptographically broken and omitted intentionally. Keys must be exactly 24 bytes (three independent 8-byte DES keys = 192-bit key material, ~112-bit effective security).

Warning

3DES is a legacy cipher. Its 64-bit block size makes it vulnerable to birthday attacks (Sweet32) in long sessions. Prefer AES for new designs.

Only CBC mode is defined for DES in PSA Crypto.

local des = require("@eryx/crypto/des")

-- Key MUST be exactly 24 bytes.
local key = buffer.fromstring("123456789012345678901234")
local iv  = buffer.fromstring("12345678")  -- 8 bytes
local ct  = des.cbc_encrypt(key, iv, buffer.fromstring("Hello!!"))
local pt  = des.cbc_decrypt(key, iv, ct)

Summary

Functions

des.encryptCBC(key: buffer, iv: buffer, data: buffer) → buffer
des.decryptCBC(key: buffer, iv: buffer, data: buffer) → buffer

API Reference

Functions

des.encryptCBC

Encrypts data with 3DES-CBC (PKCS#7 padding).

The block size is 8 bytes, so the IV must also be 8 bytes. PKCS#7 padding is applied automatically, rounding the output up to the next 8-byte boundary.

des.encryptCBC(key: buffer, iv: buffer, data: buffer) → buffer

Parameters

key: buffer

Triple-DES key - exactly 24 bytes.

iv: buffer

Initialisation vector - 8 bytes.

data: buffer

Plaintext to encrypt.

Returns

buffer

Ciphertext.

des.decryptCBC

Decrypts 3DES-CBC ciphertext (strips PKCS#7 padding).

des.decryptCBC(key: buffer, iv: buffer, data: buffer) → buffer

Parameters

key: buffer

Triple-DES key - exactly 24 bytes.

iv: buffer

Initialisation vector - 8 bytes.

data: buffer

Ciphertext to decrypt.

Returns

buffer

Plaintext.