esphome/esphome/components/nfc/nfc.cpp
2021-12-02 09:03:51 +13:00

108 lines
2.9 KiB
C++

#include "nfc.h"
#include <cstdio>
#include "esphome/core/log.h"
namespace esphome {
namespace nfc {
static const char *const TAG = "nfc";
std::string format_uid(std::vector<uint8_t> &uid) {
char buf[(uid.size() * 2) + uid.size() - 1];
int offset = 0;
for (size_t i = 0; i < uid.size(); i++) {
const char *format = "%02X";
if (i + 1 < uid.size())
format = "%02X-";
offset += sprintf(buf + offset, format, uid[i]);
}
return std::string(buf);
}
std::string format_bytes(std::vector<uint8_t> &bytes) {
char buf[(bytes.size() * 2) + bytes.size() - 1];
int offset = 0;
for (size_t i = 0; i < bytes.size(); i++) {
const char *format = "%02X";
if (i + 1 < bytes.size())
format = "%02X ";
offset += sprintf(buf + offset, format, bytes[i]);
}
return std::string(buf);
}
uint8_t guess_tag_type(uint8_t uid_length) {
if (uid_length == 4) {
return TAG_TYPE_MIFARE_CLASSIC;
} else {
return TAG_TYPE_2;
}
}
uint8_t get_mifare_classic_ndef_start_index(std::vector<uint8_t> &data) {
for (uint8_t i = 0; i < MIFARE_CLASSIC_BLOCK_SIZE; i++) {
if (data[i] == 0x00) {
// Do nothing, skip
} else if (data[i] == 0x03) {
return i;
} else {
return -2;
}
}
return -1;
}
bool decode_mifare_classic_tlv(std::vector<uint8_t> &data, uint32_t &message_length, uint8_t &message_start_index) {
uint8_t i = get_mifare_classic_ndef_start_index(data);
if (i < 0 || data[i] != 0x03) {
ESP_LOGE(TAG, "Error, Can't decode message length.");
return false;
}
if (data[i + 1] == 0xFF) {
message_length = ((0xFF & data[i + 2]) << 8) | (0xFF & data[i + 3]);
message_start_index = i + MIFARE_CLASSIC_LONG_TLV_SIZE;
} else {
message_length = data[i + 1];
message_start_index = i + MIFARE_CLASSIC_SHORT_TLV_SIZE;
}
return true;
}
uint32_t get_mifare_ultralight_buffer_size(uint32_t message_length) {
uint32_t buffer_size = message_length + 2 + 1;
if (buffer_size % MIFARE_ULTRALIGHT_READ_SIZE != 0)
buffer_size = ((buffer_size / MIFARE_ULTRALIGHT_READ_SIZE) + 1) * MIFARE_ULTRALIGHT_READ_SIZE;
return buffer_size;
}
uint32_t get_mifare_classic_buffer_size(uint32_t message_length) {
uint32_t buffer_size = message_length;
if (message_length < 255) {
buffer_size += MIFARE_CLASSIC_SHORT_TLV_SIZE + 1;
} else {
buffer_size += MIFARE_CLASSIC_LONG_TLV_SIZE + 1;
}
if (buffer_size % MIFARE_CLASSIC_BLOCK_SIZE != 0) {
buffer_size = ((buffer_size / MIFARE_CLASSIC_BLOCK_SIZE) + 1) * MIFARE_CLASSIC_BLOCK_SIZE;
}
return buffer_size;
}
bool mifare_classic_is_first_block(uint8_t block_num) {
if (block_num < 128) {
return (block_num % 4 == 0);
} else {
return (block_num % 16 == 0);
}
}
bool mifare_classic_is_trailer_block(uint8_t block_num) {
if (block_num < 128) {
return ((block_num + 1) % 4 == 0);
} else {
return ((block_num + 1) % 16 == 0);
}
}
} // namespace nfc
} // namespace esphome