proto_crypto.cpp File Reference

Cryptographic helpers for the IO-Homecontrol protocol. More...

#include "proto_crypto.h"
#include <esp_random.h>
#include <cstring>

Include dependency graph for proto_crypto.cpp:

Go to the source code of this file.

Namespaces
namespace	esphome
namespace	esphome::home_io_control
namespace	esphome::home_io_control::crypto

Functions
void	esphome::home_io_control::crypto::compute_checksum (uint8_t byte, uint8_t &c1, uint8_t &c2)
	Proprietary checksum algorithm used in IV construction.
void	esphome::home_io_control::crypto::construct_iv (const uint8_t *data, uint8_t len, const uint8_t challenge[HMAC_SIZE], uint8_t iv[IV_SIZE])
	Construct the 16-byte initialization vector (IV) for AES encryption.
bool	esphome::home_io_control::crypto::aes128_encrypt (const uint8_t in[AES_BLOCK_SIZE], const uint8_t key[AES_KEY_SIZE], uint8_t out[AES_BLOCK_SIZE])
	AES-128 ECB encrypt a single 16-byte block.
bool	esphome::home_io_control::crypto::aes128_decrypt (const uint8_t in[AES_BLOCK_SIZE], const uint8_t key[AES_KEY_SIZE], uint8_t out[AES_BLOCK_SIZE])
	AES‑128 ECB decrypt a single 16‑byte block.
bool	esphome::home_io_control::crypto::create_hmac (const uint8_t *data, uint8_t len, const uint8_t challenge[HMAC_SIZE], const uint8_t key[AES_KEY_SIZE], uint8_t hmac[HMAC_SIZE])
	Create a 6-byte HMAC for authentication (proprietary IO-Homecontrol scheme).
bool	esphome::home_io_control::crypto::verify_hmac (const uint8_t *data, uint8_t len, const uint8_t hmac[HMAC_SIZE], const uint8_t challenge[HMAC_SIZE], const uint8_t key[AES_KEY_SIZE])
	Verify a received HMAC using constant-time comparison.
bool	esphome::home_io_control::crypto::crypt_key (const uint8_t *data, uint8_t len, const uint8_t challenge[HMAC_SIZE], const uint8_t in[AES_KEY_SIZE], uint8_t out[AES_KEY_SIZE])
	Encrypt or decrypt a system key during pairing.
void	esphome::home_io_control::crypto::generate_challenge (uint8_t out[HMAC_SIZE])
	Generate 6 random bytes for a challenge using the ESP32 hardware RNG.

Detailed Description

Cryptographic helpers for the IO-Homecontrol protocol.

Definition in file proto_crypto.cpp.