Crypt module (#549)

- Moved cryptography code out of Tactility project and into a kernel module.
- Converted C++ code to C style interface
- Hardened security

TactilityCore/Include/Tactility/crypt/Crypt.h

@@ -1,64 +0,0 @@
-/** @file secure.h
- *
- * @brief Hardware-bound encryption methods.
- * @warning Enable secure boot and flash encryption to increase security.
- *
- * Offers AES 256 CBC encryption with built-in key.
- * The key is built from data including:
- *  - the internal factory MAC address
- *  - random data stored in NVS
- *
- * It's important to use flash encryption to avoid an attacker to get
- * access to your encrypted data. If flash encryption is disabled,
- * someone can fetch the key from the partitions.
- *
- * See:
- * https://docs.espressif.com/projects/esp-idf/en/latest/esp32/security/secure-boot-v2.html
- * https://docs.espressif.com/projects/esp-idf/en/latest/esp32/security/flash-encryption.html
- */
-#pragma once
-
-#include <cstdio>
-#include <cstdint>
-#include <string>
-
-namespace tt::crypt {
-
-/**
- * @brief Fills the IV with zeros and then creates an IV based on the input data.
- * @param[in] data input data
- * @param[in] dataLength input data length
- * @param[out] iv output IV
- */
-void getIv(const void* data, size_t dataLength, uint8_t iv[16]);
-
-/**
- * @brief Encrypt data.
- *
- * Important: Use flash encryption to increase security.
- * Important: input and output data must be aligned to 16 bytes.
- *
- * @param[in] iv the AES IV
- * @param[in] inData input data
- * @param[out] outData output data
- * @param[in] dataLength data length, a multiple of 16 (for both inData and outData)
- * @return the result of esp_aes_crypt_cbc() (MBEDTLS_ERR_*)
- */
-int encrypt(const uint8_t iv[16], const uint8_t* inData, uint8_t* outData, size_t dataLength);
-
-/**
- * @brief Decrypt data.
- *
- * Important: Use flash encryption to increase security.
- * Important: input and output data must be aligned to 16 bytes.
- *
- * @param[in] iv AES IV
- * @param[in] inData input data
- * @param[out] outData output data
- * @param[in] dataLength data length, a multiple of 16 (for both inData and outData)
- * @return the result of esp_aes_crypt_cbc() (MBEDTLS_ERR_*)
- */
-int decrypt(const uint8_t iv[16], const uint8_t* inData, uint8_t* outData, size_t dataLength);
-
-
-} // namespace

TactilityCore/Include/Tactility/crypt/Hash.h

@@ -1,23 +0,0 @@
-#pragma once
-
-#include <cstddef>
-#include <cstdint>
-
-namespace tt::crypt {
-
-/**
- * Implementation of DJB2 hashing algorithm.
- * @param[in] str the string to calculate the hash for
- * @return the hash
- */
-uint32_t djb2(const char* str);
-
-/**
- * Implementation of DJB2 hashing algorithm.
- * @param[in] data the bytes to calculate the hash for
- * @param[in] length the size of data
- * @return the hash
- */
-uint32_t djb2(const void* data, size_t length);
-
-} // namespace