flipperzero-firmware/lib/subghz/blocks/math.h

#pragma once

#include <stdbool.h>
#include <stdint.h>
#include <stddef.h>

#define bit_read(value, bit) (((value) >> (bit)) & 0x01)
#define bit_set(value, bit) ((value) |= (1UL << (bit)))
#define bit_clear(value, bit) ((value) &= ~(1UL << (bit)))
#define bit_write(value, bit, bitvalue) (bitvalue ? bit_set(value, bit) : bit_clear(value, bit))
#define DURATION_DIFF(x, y) ((x < y) ? (y - x) : (x - y))
#define abs(x) ((x) > 0 ? (x) : -(x))

#ifdef __cplusplus
extern "C" {
#endif
/**
 * Flip the data bitwise.
 * @param key In data
 * @param count_bit number of data bits
 * @return Reverse data
 **/
uint64_t subghz_protocol_blocks_reverse_key(uint64_t key, uint8_t count_bit);

/**
 * Get parity the data bitwise.
 * @param key In data
 * @param count_bit number of data bits
 * @return parity
 **/
uint8_t subghz_protocol_blocks_get_parity(uint64_t key, uint8_t count_bit);

/**
 * CRC-4.
 * @param message array of bytes to check
 * @param nBytes number of bytes in message
 * @param polynomial CRC polynomial
 * @param init starting crc value
 * @return CRC value
 **/
uint8_t subghz_protocol_blocks_crc4(
    uint8_t const message[],
    unsigned nBytes,
    uint8_t polynomial,
    uint8_t init);

/**
 * CRC-7.
 * @param message array of bytes to check
 * @param nBytes number of bytes in message
 * @param polynomial CRC polynomial
 * @param init starting crc value
 * @return CRC value
 **/
uint8_t subghz_protocol_blocks_crc7(
    uint8_t const message[],
    unsigned nBytes,
    uint8_t polynomial,
    uint8_t init);

/**
 * Generic Cyclic Redundancy Check CRC-8.
 * Example polynomial: 0x31 = x8 + x5 + x4 + 1 (x8 is implicit)
 * Example polynomial: 0x80 = x8 + x7 (a normal bit-by-bit parity XOR)
 * @param message array of bytes to check
 * @param nBytes number of bytes in message
 * @param polynomial byte is from x^7 to x^0 (x^8 is implicitly one)
 * @param init starting crc value
 * @return CRC value
 **/
uint8_t subghz_protocol_blocks_crc8(
    uint8_t const message[],
    unsigned nBytes,
    uint8_t polynomial,
    uint8_t init);

/**
 * "Little-endian" Cyclic Redundancy Check CRC-8 LE
 *  Input and output are reflected, i.e. least significant bit is shifted in first.
 *  @param message array of bytes to check
 *  @param nBytes number of bytes in message
 *  @param polynomial CRC polynomial
 *  @param init starting crc value
 *  @return CRC value
 **/
uint8_t subghz_protocol_blocks_crc8le(
    uint8_t const message[],
    unsigned nBytes,
    uint8_t polynomial,
    uint8_t init);

/**
 *  CRC-16 LSB.
 *  Input and output are reflected, i.e. least significant bit is shifted in first.
 *  Note that poly and init already need to be reflected.
 *  @param message array of bytes to check
 *  @param nBytes number of bytes in message
 *  @param polynomial CRC polynomial
 *  @param init starting crc value
 *  @return CRC value
 **/
uint16_t subghz_protocol_blocks_crc16lsb(
    uint8_t const message[],
    unsigned nBytes,
    uint16_t polynomial,
    uint16_t init);

/**
 * CRC-16.
 *  @param message array of bytes to check
 *  @param nBytes number of bytes in message
 *  @param polynomial CRC polynomial
 *  @param init starting crc value
 *  @return CRC value
 **/
uint16_t subghz_protocol_blocks_crc16(
    uint8_t const message[],
    unsigned nBytes,
    uint16_t polynomial,
    uint16_t init);

/**
 *  Digest-8 by "LFSR-based Toeplitz hash".
 *  @param message bytes of message data
 *  @param bytes number of bytes to digest
 *  @param gen key stream generator, needs to includes the MSB if the LFSR is rolling
 *  @param key initial key
 *  @return digest value
 **/
uint8_t subghz_protocol_blocks_lfsr_digest8(
    uint8_t const message[],
    unsigned bytes,
    uint8_t gen,
    uint8_t key);

/**
 *  Digest-8 by "LFSR-based Toeplitz hash", byte reflect, bit reflect.
 *  @param message bytes of message data
 *  @param bytes number of bytes to digest
 *  @param gen key stream generator, needs to includes the MSB if the LFSR is rolling
 *  @param key initial key
 *  @return digest value
 **/
uint8_t subghz_protocol_blocks_lfsr_digest8_reflect(
    uint8_t const message[],
    int bytes,
    uint8_t gen,
    uint8_t key);

/**
 *  Digest-16 by "LFSR-based Toeplitz hash".
 *  @param message bytes of message data
 *  @param bytes number of bytes to digest
 *  @param gen key stream generator, needs to includes the MSB if the LFSR is rolling
 *  @param key initial key
 *  @return digest value
 **/
uint16_t subghz_protocol_blocks_lfsr_digest16(
    uint8_t const message[],
    unsigned bytes,
    uint16_t gen,
    uint16_t key);

/**
 *  Compute Addition of a number of bytes.
 *  @param message bytes of message data
 *  @param num_bytes number of bytes to sum
 *  @return summation value
 **/
uint8_t subghz_protocol_blocks_add_bytes(uint8_t const message[], size_t num_bytes);

/**
 *  Compute bit parity of a single byte (8 bits).
 *  @param byte single byte to check
 *  @return 1 odd parity, 0 even parity
 **/
int subghz_protocol_blocks_parity8(uint8_t byte);

/**
 *  Compute bit parity of a number of bytes.
 *  @param message bytes of message data
 *  @param num_bytes number of bytes to sum
 *  @return 1 odd parity, 0 even parity
 **/
int subghz_protocol_blocks_parity_bytes(uint8_t const message[], size_t num_bytes);

/**
 *  Compute XOR (byte-wide parity) of a number of bytes.
 *  @param message bytes of message data
 *  @param num_bytes number of bytes to sum
 *  @return summation value, per bit-position 1 odd parity, 0 even parity
 **/
uint8_t subghz_protocol_blocks_xor_bytes(uint8_t const message[], size_t num_bytes);

#ifdef __cplusplus
}
#endif