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Fix buffer overflow in mifare classic lib #1374

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This commit is contained in:
gornekich
2022-07-05 18:41:19 +03:00
committed by GitHub
parent e147b2ceea
commit ece142a667
1 changed files with 18 additions and 4 deletions
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20
lib/nfc_protocols/mifare_classic.c
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@@ -386,13 +386,27 @@ bool mf_classic_read_block(
tx_rx->tx_rx_type = FuriHalNfcTxRxTypeRaw;
if(furi_hal_nfc_tx_rx(tx_rx, 50)) {
if(tx_rx->rx_bits == 8 * 18) {
for(uint8_t i = 0; i < 18; i++) {
block->value[i] = crypto1_byte(crypto, 0, 0) ^ tx_rx->rx_data[i];
if(tx_rx->rx_bits == 8 * (MF_CLASSIC_BLOCK_SIZE + 2)) {
uint8_t block_received[MF_CLASSIC_BLOCK_SIZE + 2];
for(uint8_t i = 0; i < MF_CLASSIC_BLOCK_SIZE + 2; i++) {
block_received[i] = crypto1_byte(crypto, 0, 0) ^ tx_rx->rx_data[i];
}
uint16_t crc_calc = nfca_get_crc16(block_received, MF_CLASSIC_BLOCK_SIZE);
uint16_t crc_received = (block_received[MF_CLASSIC_BLOCK_SIZE + 1] << 8) |
block_received[MF_CLASSIC_BLOCK_SIZE];
if(crc_received != crc_calc) {
FURI_LOG_E(
TAG,
"Incorrect CRC while reading block %d. Expected %04X, Received %04X",
block_num,
crc_received,
crc_calc);
} else {
memcpy(block->value, block_received, MF_CLASSIC_BLOCK_SIZE);
read_block_success = true;
}
}
}
return read_block_success;
}