firmware/src/mesh/CryptoEngine.h
2024-10-10 18:14:11 +08:00

97 lines
3.1 KiB
C++

#pragma once
#include "AES.h"
#include "CTR.h"
#include "concurrency/LockGuard.h"
#include "configuration.h"
#include "mesh-pb-constants.h"
#include <Arduino.h>
extern concurrency::Lock *cryptLock;
struct CryptoKey {
uint8_t bytes[32];
/// # of bytes, or -1 to mean "invalid key - do not use"
int8_t length;
};
/**
* see docs/software/crypto.md for details.
*
*/
#define MAX_BLOCKSIZE 256
#define TEST_CURVE25519_FIELD_OPS // Exposes Curve25519::isWeakPoint() for testing keys
class CryptoEngine
{
public:
#if !(MESHTASTIC_EXCLUDE_PKI)
uint8_t public_key[32] = {0};
#endif
virtual ~CryptoEngine() {}
#if !(MESHTASTIC_EXCLUDE_PKI)
#if !(MESHTASTIC_EXCLUDE_PKI_KEYGEN)
virtual void generateKeyPair(uint8_t *pubKey, uint8_t *privKey);
virtual bool regeneratePublicKey(uint8_t *pubKey, uint8_t *privKey);
#endif
void clearKeys();
void setDHPrivateKey(uint8_t *_private_key);
virtual bool encryptCurve25519(uint32_t toNode, uint32_t fromNode, meshtastic_UserLite_public_key_t remotePublic,
uint64_t packetNum, size_t numBytes, uint8_t *bytes, uint8_t *bytesOut);
virtual bool decryptCurve25519(uint32_t fromNode, meshtastic_UserLite_public_key_t remotePublic, uint64_t packetNum,
size_t numBytes, uint8_t *bytes, uint8_t *bytesOut);
virtual bool setDHPublicKey(uint8_t *publicKey);
virtual void hash(uint8_t *bytes, size_t numBytes);
virtual void aesSetKey(const uint8_t *key, size_t key_len);
virtual void aesEncrypt(uint8_t *in, uint8_t *out);
AESSmall256 *aes = NULL;
#endif
/**
* Set the key used for encrypt, decrypt.
*
* As a special case: If all bytes are zero, we assume _no encryption_ and send all data in cleartext.
*
* @param numBytes must be 16 (AES128), 32 (AES256) or 0 (no crypt)
* @param bytes a _static_ buffer that will remain valid for the life of this crypto instance (i.e. this class will cache the
* provided pointer)
*/
virtual void setKey(const CryptoKey &k);
/**
* Encrypt a packet
*
* @param bytes is updated in place
*/
virtual void encryptPacket(uint32_t fromNode, uint64_t packetId, size_t numBytes, uint8_t *bytes);
virtual void decrypt(uint32_t fromNode, uint64_t packetId, size_t numBytes, uint8_t *bytes);
virtual void encryptAESCtr(CryptoKey key, uint8_t *nonce, size_t numBytes, uint8_t *bytes);
#ifndef PIO_UNIT_TESTING
protected:
#endif
/** Our per packet nonce */
uint8_t nonce[16] = {0};
CryptoKey key = {};
CTRCommon *ctr = NULL;
#if !(MESHTASTIC_EXCLUDE_PKI)
uint8_t shared_key[32] = {0};
uint8_t private_key[32] = {0};
#endif
/**
* Init our 128 bit nonce for a new packet
*
* The NONCE is constructed by concatenating (from MSB to LSB):
* a 64 bit packet number (stored in little endian order)
* a 32 bit sending node number (stored in little endian order)
* a 32 bit block counter (starts at zero)
*/
void initNonce(uint32_t fromNode, uint64_t packetId, uint32_t extraNonce = 0);
};
extern CryptoEngine *crypto;