flipperzero-firmware/lib/nfc/protocols/nfca.c
Walter Doekes 611b7e15ed
Remove execute permissions from *.c and *.h files (#1651)
* Add permission fix (no execute bit for source files) to fbt lint|format
* Remove execute bit from 59 source files using fbt format
* Also list which permissions are unwanted in lint.py
* Also remove exec permissions from lib/../rfal_nfc.c

Co-authored-by: あく <alleteam@gmail.com>
2022-08-30 01:20:57 +09:00

143 lines
4.0 KiB
C

#include "nfca.h"
#include <string.h>
#include <stdio.h>
#include <furi.h>
#define NFCA_CMD_RATS (0xE0U)
#define NFCA_CRC_INIT (0x6363)
#define NFCA_F_SIG (13560000.0)
#define T_SIG 7374 //73.746ns*100
#define T_SIG_x8 58992 //T_SIG*8
#define T_SIG_x8_x8 471936 //T_SIG*8*8
#define T_SIG_x8_x9 530928 //T_SIG*8*9
#define NFCA_SIGNAL_MAX_EDGES (1350)
typedef struct {
uint8_t cmd;
uint8_t param;
} nfca_cmd_rats;
static uint8_t nfca_default_ats[] = {0x05, 0x78, 0x80, 0x80, 0x00};
static uint8_t nfca_sleep_req[] = {0x50, 0x00};
uint16_t nfca_get_crc16(uint8_t* buff, uint16_t len) {
uint16_t crc = NFCA_CRC_INIT;
uint8_t byte = 0;
for(uint8_t i = 0; i < len; i++) {
byte = buff[i];
byte ^= (uint8_t)(crc & 0xff);
byte ^= byte << 4;
crc = (crc >> 8) ^ (((uint16_t)byte) << 8) ^ (((uint16_t)byte) << 3) ^
(((uint16_t)byte) >> 4);
}
return crc;
}
void nfca_append_crc16(uint8_t* buff, uint16_t len) {
uint16_t crc = nfca_get_crc16(buff, len);
buff[len] = (uint8_t)crc;
buff[len + 1] = (uint8_t)(crc >> 8);
}
bool nfca_emulation_handler(
uint8_t* buff_rx,
uint16_t buff_rx_len,
uint8_t* buff_tx,
uint16_t* buff_tx_len) {
bool sleep = false;
uint8_t rx_bytes = buff_rx_len / 8;
if(rx_bytes == sizeof(nfca_sleep_req) && !memcmp(buff_rx, nfca_sleep_req, rx_bytes)) {
sleep = true;
} else if(rx_bytes == sizeof(nfca_cmd_rats) && buff_rx[0] == NFCA_CMD_RATS) {
memcpy(buff_tx, nfca_default_ats, sizeof(nfca_default_ats));
*buff_tx_len = sizeof(nfca_default_ats) * 8;
}
return sleep;
}
static void nfca_add_bit(DigitalSignal* signal, bool bit) {
if(bit) {
signal->start_level = true;
for(size_t i = 0; i < 7; i++) {
signal->edge_timings[i] = T_SIG_x8;
}
signal->edge_timings[7] = T_SIG_x8_x9;
signal->edge_cnt = 8;
} else {
signal->start_level = false;
signal->edge_timings[0] = T_SIG_x8_x8;
for(size_t i = 1; i < 9; i++) {
signal->edge_timings[i] = T_SIG_x8;
}
signal->edge_cnt = 9;
}
}
static void nfca_add_byte(NfcaSignal* nfca_signal, uint8_t byte, bool parity) {
for(uint8_t i = 0; i < 8; i++) {
if(byte & (1 << i)) {
digital_signal_append(nfca_signal->tx_signal, nfca_signal->one);
} else {
digital_signal_append(nfca_signal->tx_signal, nfca_signal->zero);
}
}
if(parity) {
digital_signal_append(nfca_signal->tx_signal, nfca_signal->one);
} else {
digital_signal_append(nfca_signal->tx_signal, nfca_signal->zero);
}
}
NfcaSignal* nfca_signal_alloc() {
NfcaSignal* nfca_signal = malloc(sizeof(NfcaSignal));
nfca_signal->one = digital_signal_alloc(10);
nfca_signal->zero = digital_signal_alloc(10);
nfca_add_bit(nfca_signal->one, true);
nfca_add_bit(nfca_signal->zero, false);
nfca_signal->tx_signal = digital_signal_alloc(NFCA_SIGNAL_MAX_EDGES);
return nfca_signal;
}
void nfca_signal_free(NfcaSignal* nfca_signal) {
furi_assert(nfca_signal);
digital_signal_free(nfca_signal->one);
digital_signal_free(nfca_signal->zero);
digital_signal_free(nfca_signal->tx_signal);
free(nfca_signal);
}
void nfca_signal_encode(NfcaSignal* nfca_signal, uint8_t* data, uint16_t bits, uint8_t* parity) {
furi_assert(nfca_signal);
furi_assert(data);
furi_assert(parity);
nfca_signal->tx_signal->edge_cnt = 0;
nfca_signal->tx_signal->start_level = true;
// Start of frame
digital_signal_append(nfca_signal->tx_signal, nfca_signal->one);
if(bits < 8) {
for(size_t i = 0; i < bits; i++) {
if(FURI_BIT(data[0], i)) {
digital_signal_append(nfca_signal->tx_signal, nfca_signal->one);
} else {
digital_signal_append(nfca_signal->tx_signal, nfca_signal->zero);
}
}
} else {
for(size_t i = 0; i < bits / 8; i++) {
nfca_add_byte(nfca_signal, data[i], parity[i / 8] & (1 << (7 - (i & 0x07))));
}
}
}