#include "mifare_classic.h" #include "nfca.h" #include "nfc_util.h" #include // Algorithm from https://github.com/RfidResearchGroup/proxmark3.git #define TAG "MfClassic" #define MF_CLASSIC_AUTH_KEY_A_CMD (0x60U) #define MF_CLASSIC_AUTH_KEY_B_CMD (0x61U) #define MF_CLASSIC_READ_SECT_CMD (0x30) typedef enum { MfClassicActionDataRead, MfClassicActionDataWrite, MfClassicActionDataInc, MfClassicActionDataDec, MfClassicActionKeyARead, MfClassicActionKeyAWrite, MfClassicActionKeyBRead, MfClassicActionKeyBWrite, MfClassicActionACRead, MfClassicActionACWrite, } MfClassicAction; const char* mf_classic_get_type_str(MfClassicType type) { if(type == MfClassicType1k) { return "MIFARE Classic 1K"; } else if(type == MfClassicType4k) { return "MIFARE Classic 4K"; } else { return "Unknown"; } } static uint8_t mf_classic_get_first_block_num_of_sector(uint8_t sector) { furi_assert(sector < 40); if(sector < 32) { return sector * 4; } else { return 32 * 4 + (sector - 32) * 16; } } uint8_t mf_classic_get_sector_trailer_block_num_by_sector(uint8_t sector) { furi_assert(sector < 40); if(sector < 32) { return sector * 4 + 3; } else { return 32 * 4 + (sector - 32) * 16 + 15; } } uint8_t mf_classic_get_sector_by_block(uint8_t block) { if(block < 128) { return (block | 0x03) / 4; } else { return 32 + ((block | 0xf) - 32 * 4) / 16; } } static uint8_t mf_classic_get_blocks_num_in_sector(uint8_t sector) { furi_assert(sector < 40); return sector < 32 ? 4 : 16; } uint8_t mf_classic_get_sector_trailer_num_by_block(uint8_t block) { if(block < 128) { return block | 0x03; } else { return block | 0x0f; } } bool mf_classic_is_sector_trailer(uint8_t block) { return block == mf_classic_get_sector_trailer_num_by_block(block); } MfClassicSectorTrailer* mf_classic_get_sector_trailer_by_sector(MfClassicData* data, uint8_t sector) { furi_assert(data); uint8_t sec_tr_block_num = mf_classic_get_sector_trailer_block_num_by_sector(sector); return (MfClassicSectorTrailer*)data->block[sec_tr_block_num].value; } uint8_t mf_classic_get_total_sectors_num(MfClassicType type) { if(type == MfClassicType1k) { return MF_CLASSIC_1K_TOTAL_SECTORS_NUM; } else if(type == MfClassicType4k) { return MF_CLASSIC_4K_TOTAL_SECTORS_NUM; } else { return 0; } } static uint16_t mf_classic_get_total_block_num(MfClassicType type) { if(type == MfClassicType1k) { return 64; } else if(type == MfClassicType4k) { return 256; } else { return 0; } } bool mf_classic_is_block_read(MfClassicData* data, uint8_t block_num) { furi_assert(data); return (FURI_BIT(data->block_read_mask[block_num / 32], block_num % 32) == 1); } void mf_classic_set_block_read(MfClassicData* data, uint8_t block_num, MfClassicBlock* block_data) { furi_assert(data); if(mf_classic_is_sector_trailer(block_num)) { memcpy(&data->block[block_num].value[6], &block_data->value[6], 4); } else { memcpy(data->block[block_num].value, block_data->value, MF_CLASSIC_BLOCK_SIZE); } FURI_BIT_SET(data->block_read_mask[block_num / 32], block_num % 32); } bool mf_classic_is_key_found(MfClassicData* data, uint8_t sector_num, MfClassicKey key_type) { furi_assert(data); bool key_found = false; if(key_type == MfClassicKeyA) { key_found = (FURI_BIT(data->key_a_mask, sector_num) == 1); } else if(key_type == MfClassicKeyB) { key_found = (FURI_BIT(data->key_b_mask, sector_num) == 1); } return key_found; } void mf_classic_set_key_found( MfClassicData* data, uint8_t sector_num, MfClassicKey key_type, uint64_t key) { furi_assert(data); uint8_t key_arr[6] = {}; MfClassicSectorTrailer* sec_trailer = mf_classic_get_sector_trailer_by_sector(data, sector_num); nfc_util_num2bytes(key, 6, key_arr); if(key_type == MfClassicKeyA) { memcpy(sec_trailer->key_a, key_arr, sizeof(sec_trailer->key_a)); FURI_BIT_SET(data->key_a_mask, sector_num); } else if(key_type == MfClassicKeyB) { memcpy(sec_trailer->key_b, key_arr, sizeof(sec_trailer->key_b)); FURI_BIT_SET(data->key_b_mask, sector_num); } } bool mf_classic_is_sector_read(MfClassicData* data, uint8_t sector_num) { furi_assert(data); bool sector_read = false; do { if(!mf_classic_is_key_found(data, sector_num, MfClassicKeyA)) break; if(!mf_classic_is_key_found(data, sector_num, MfClassicKeyB)) break; uint8_t start_block = mf_classic_get_first_block_num_of_sector(sector_num); uint8_t total_blocks = mf_classic_get_blocks_num_in_sector(sector_num); uint8_t block_read = true; for(size_t i = start_block; i < start_block + total_blocks; i++) { block_read = mf_classic_is_block_read(data, i); if(!block_read) break; } sector_read = block_read; } while(false); return sector_read; } void mf_classic_get_read_sectors_and_keys( MfClassicData* data, uint8_t* sectors_read, uint8_t* keys_found) { furi_assert(data); *sectors_read = 0; *keys_found = 0; uint8_t sectors_total = mf_classic_get_total_sectors_num(data->type); for(size_t i = 0; i < sectors_total; i++) { if(mf_classic_is_key_found(data, i, MfClassicKeyA)) { *keys_found += 1; } if(mf_classic_is_key_found(data, i, MfClassicKeyB)) { *keys_found += 1; } uint8_t first_block = mf_classic_get_first_block_num_of_sector(i); uint8_t total_blocks_in_sec = mf_classic_get_blocks_num_in_sector(i); bool blocks_read = true; for(size_t i = first_block; i < first_block + total_blocks_in_sec; i++) { blocks_read = mf_classic_is_block_read(data, i); if(!blocks_read) break; } if(blocks_read) { *sectors_read += 1; } } } static bool mf_classic_is_allowed_access_sector_trailer( MfClassicEmulator* emulator, uint8_t block_num, MfClassicKey key, MfClassicAction action) { uint8_t* sector_trailer = emulator->data.block[block_num].value; uint8_t AC = ((sector_trailer[7] >> 5) & 0x04) | ((sector_trailer[8] >> 2) & 0x02) | ((sector_trailer[8] >> 7) & 0x01); switch(action) { case MfClassicActionKeyARead: { return false; } case MfClassicActionKeyAWrite: { return ( (key == MfClassicKeyA && (AC == 0x00 || AC == 0x01)) || (key == MfClassicKeyB && (AC == 0x04 || AC == 0x03))); } case MfClassicActionKeyBRead: { return (key == MfClassicKeyA && (AC == 0x00 || AC == 0x02 || AC == 0x01)); } case MfClassicActionKeyBWrite: { return ( (key == MfClassicKeyA && (AC == 0x00 || AC == 0x01)) || (key == MfClassicKeyB && (AC == 0x04 || AC == 0x03))); } case MfClassicActionACRead: { return ( (key == MfClassicKeyA) || (key == MfClassicKeyB && !(AC == 0x00 || AC == 0x02 || AC == 0x01))); } case MfClassicActionACWrite: { return ( (key == MfClassicKeyA && (AC == 0x01)) || (key == MfClassicKeyB && (AC == 0x03 || AC == 0x05))); } default: return false; } return true; } static bool mf_classic_is_allowed_access_data_block( MfClassicEmulator* emulator, uint8_t block_num, MfClassicKey key, MfClassicAction action) { uint8_t* sector_trailer = emulator->data.block[mf_classic_get_sector_trailer_num_by_block(block_num)].value; uint8_t sector_block; if(block_num <= 128) { sector_block = block_num & 0x03; } else { sector_block = (block_num & 0x0f) / 5; } uint8_t AC; switch(sector_block) { case 0x00: { AC = ((sector_trailer[7] >> 2) & 0x04) | ((sector_trailer[8] << 1) & 0x02) | ((sector_trailer[8] >> 4) & 0x01); break; } case 0x01: { AC = ((sector_trailer[7] >> 3) & 0x04) | ((sector_trailer[8] >> 0) & 0x02) | ((sector_trailer[8] >> 5) & 0x01); break; } case 0x02: { AC = ((sector_trailer[7] >> 4) & 0x04) | ((sector_trailer[8] >> 1) & 0x02) | ((sector_trailer[8] >> 6) & 0x01); break; } default: return false; } switch(action) { case MfClassicActionDataRead: { return ( (key == MfClassicKeyA && !(AC == 0x03 || AC == 0x05 || AC == 0x07)) || (key == MfClassicKeyB && !(AC == 0x07))); } case MfClassicActionDataWrite: { return ( (key == MfClassicKeyA && (AC == 0x00)) || (key == MfClassicKeyB && (AC == 0x00 || AC == 0x04 || AC == 0x06 || AC == 0x03))); } case MfClassicActionDataInc: { return ( (key == MfClassicKeyA && (AC == 0x00)) || (key == MfClassicKeyB && (AC == 0x00 || AC == 0x06))); } case MfClassicActionDataDec: { return ( (key == MfClassicKeyA && (AC == 0x00 || AC == 0x06 || AC == 0x01)) || (key == MfClassicKeyB && (AC == 0x00 || AC == 0x06 || AC == 0x01))); } default: return false; } return false; } static bool mf_classic_is_allowed_access( MfClassicEmulator* emulator, uint8_t block_num, MfClassicKey key, MfClassicAction action) { if(mf_classic_is_sector_trailer(block_num)) { return mf_classic_is_allowed_access_sector_trailer(emulator, block_num, key, action); } else { return mf_classic_is_allowed_access_data_block(emulator, block_num, key, action); } } bool mf_classic_check_card_type(uint8_t ATQA0, uint8_t ATQA1, uint8_t SAK) { UNUSED(ATQA1); if((ATQA0 == 0x44 || ATQA0 == 0x04) && (SAK == 0x08 || SAK == 0x88 || SAK == 0x09)) { return true; } else if((ATQA0 == 0x01) && (ATQA1 == 0x0F) && (SAK == 0x01)) { //skylanders support return true; } else if((ATQA0 == 0x42 || ATQA0 == 0x02) && (SAK == 0x18)) { return true; } else { return false; } } MfClassicType mf_classic_get_classic_type(int8_t ATQA0, uint8_t ATQA1, uint8_t SAK) { UNUSED(ATQA1); if((ATQA0 == 0x44 || ATQA0 == 0x04) && (SAK == 0x08 || SAK == 0x88 || SAK == 0x09)) { return MfClassicType1k; } else if((ATQA0 == 0x01) && (ATQA1 == 0x0F) && (SAK == 0x01)) { //skylanders support return MfClassicType1k; } else if((ATQA0 == 0x42 || ATQA0 == 0x02) && (SAK == 0x18)) { return MfClassicType4k; } return MfClassicType1k; } void mf_classic_reader_add_sector( MfClassicReader* reader, uint8_t sector, uint64_t key_a, uint64_t key_b) { furi_assert(reader); furi_assert(sector < MF_CLASSIC_SECTORS_MAX); furi_assert((key_a != MF_CLASSIC_NO_KEY) || (key_b != MF_CLASSIC_NO_KEY)); if(reader->sectors_to_read < MF_CLASSIC_SECTORS_MAX) { reader->sector_reader[reader->sectors_to_read].key_a = key_a; reader->sector_reader[reader->sectors_to_read].key_b = key_b; reader->sector_reader[reader->sectors_to_read].sector_num = sector; reader->sectors_to_read++; } } void mf_classic_auth_init_context(MfClassicAuthContext* auth_ctx, uint8_t sector) { furi_assert(auth_ctx); auth_ctx->sector = sector; auth_ctx->key_a = MF_CLASSIC_NO_KEY; auth_ctx->key_b = MF_CLASSIC_NO_KEY; } static bool mf_classic_auth( FuriHalNfcTxRxContext* tx_rx, uint32_t block, uint64_t key, MfClassicKey key_type, Crypto1* crypto) { bool auth_success = false; uint32_t cuid = 0; memset(tx_rx->tx_data, 0, sizeof(tx_rx->tx_data)); memset(tx_rx->tx_parity, 0, sizeof(tx_rx->tx_parity)); tx_rx->tx_rx_type = FuriHalNfcTxRxTypeDefault; do { if(!furi_hal_nfc_activate_nfca(200, &cuid)) break; if(key_type == MfClassicKeyA) { tx_rx->tx_data[0] = MF_CLASSIC_AUTH_KEY_A_CMD; } else { tx_rx->tx_data[0] = MF_CLASSIC_AUTH_KEY_B_CMD; } tx_rx->tx_data[1] = block; tx_rx->tx_rx_type = FuriHalNfcTxRxTypeRxNoCrc; tx_rx->tx_bits = 2 * 8; if(!furi_hal_nfc_tx_rx(tx_rx, 6)) break; uint32_t nt = (uint32_t)nfc_util_bytes2num(tx_rx->rx_data, 4); crypto1_init(crypto, key); crypto1_word(crypto, nt ^ cuid, 0); uint8_t nr[4] = {}; nfc_util_num2bytes(prng_successor(DWT->CYCCNT, 32), 4, nr); for(uint8_t i = 0; i < 4; i++) { tx_rx->tx_data[i] = crypto1_byte(crypto, nr[i], 0) ^ nr[i]; tx_rx->tx_parity[0] |= (((crypto1_filter(crypto->odd) ^ nfc_util_odd_parity8(nr[i])) & 0x01) << (7 - i)); } nt = prng_successor(nt, 32); for(uint8_t i = 4; i < 8; i++) { nt = prng_successor(nt, 8); tx_rx->tx_data[i] = crypto1_byte(crypto, 0x00, 0) ^ (nt & 0xff); tx_rx->tx_parity[0] |= (((crypto1_filter(crypto->odd) ^ nfc_util_odd_parity8(nt & 0xff)) & 0x01) << (7 - i)); } tx_rx->tx_rx_type = FuriHalNfcTxRxTypeRaw; tx_rx->tx_bits = 8 * 8; if(!furi_hal_nfc_tx_rx(tx_rx, 6)) break; if(tx_rx->rx_bits == 32) { crypto1_word(crypto, 0, 0); auth_success = true; } } while(false); return auth_success; } bool mf_classic_authenticate( FuriHalNfcTxRxContext* tx_rx, uint8_t block_num, uint64_t key, MfClassicKey key_type) { furi_assert(tx_rx); Crypto1 crypto = {}; bool key_found = mf_classic_auth(tx_rx, block_num, key, key_type, &crypto); furi_hal_nfc_sleep(); return key_found; } bool mf_classic_auth_attempt( FuriHalNfcTxRxContext* tx_rx, MfClassicAuthContext* auth_ctx, uint64_t key) { furi_assert(tx_rx); furi_assert(auth_ctx); bool found_key = false; bool need_halt = (auth_ctx->key_a == MF_CLASSIC_NO_KEY) && (auth_ctx->key_b == MF_CLASSIC_NO_KEY); Crypto1 crypto; if(auth_ctx->key_a == MF_CLASSIC_NO_KEY) { // Try AUTH with key A if(mf_classic_auth( tx_rx, mf_classic_get_first_block_num_of_sector(auth_ctx->sector), key, MfClassicKeyA, &crypto)) { auth_ctx->key_a = key; found_key = true; } } if(need_halt) { furi_hal_nfc_sleep(); } if(auth_ctx->key_b == MF_CLASSIC_NO_KEY) { // Try AUTH with key B if(mf_classic_auth( tx_rx, mf_classic_get_first_block_num_of_sector(auth_ctx->sector), key, MfClassicKeyB, &crypto)) { auth_ctx->key_b = key; found_key = true; } } return found_key; } bool mf_classic_read_block( FuriHalNfcTxRxContext* tx_rx, Crypto1* crypto, uint8_t block_num, MfClassicBlock* block) { furi_assert(tx_rx); furi_assert(crypto); furi_assert(block); bool read_block_success = false; uint8_t plain_cmd[4] = {MF_CLASSIC_READ_SECT_CMD, block_num, 0x00, 0x00}; nfca_append_crc16(plain_cmd, 2); memset(tx_rx->tx_data, 0, sizeof(tx_rx->tx_data)); memset(tx_rx->tx_parity, 0, sizeof(tx_rx->tx_parity)); for(uint8_t i = 0; i < 4; i++) { tx_rx->tx_data[i] = crypto1_byte(crypto, 0x00, 0) ^ plain_cmd[i]; tx_rx->tx_parity[0] |= ((crypto1_filter(crypto->odd) ^ nfc_util_odd_parity8(plain_cmd[i])) & 0x01) << (7 - i); } tx_rx->tx_bits = 4 * 9; tx_rx->tx_rx_type = FuriHalNfcTxRxTypeRaw; if(furi_hal_nfc_tx_rx(tx_rx, 50)) { 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; } void mf_classic_read_sector(FuriHalNfcTxRxContext* tx_rx, MfClassicData* data, uint8_t sec_num) { furi_assert(tx_rx); furi_assert(data); furi_hal_nfc_sleep(); bool key_a_found = mf_classic_is_key_found(data, sec_num, MfClassicKeyA); bool key_b_found = mf_classic_is_key_found(data, sec_num, MfClassicKeyB); uint8_t start_block = mf_classic_get_first_block_num_of_sector(sec_num); uint8_t total_blocks = mf_classic_get_blocks_num_in_sector(sec_num); MfClassicBlock block_tmp = {}; uint64_t key = 0; MfClassicSectorTrailer* sec_tr = mf_classic_get_sector_trailer_by_sector(data, sec_num); Crypto1 crypto = {}; uint8_t blocks_read = 0; do { if(!key_a_found) break; FURI_LOG_D(TAG, "Try to read blocks with key A"); key = nfc_util_bytes2num(sec_tr->key_a, sizeof(sec_tr->key_a)); if(!mf_classic_auth(tx_rx, start_block, key, MfClassicKeyA, &crypto)) break; for(size_t i = start_block; i < start_block + total_blocks; i++) { if(!mf_classic_is_block_read(data, i)) { if(mf_classic_read_block(tx_rx, &crypto, i, &block_tmp)) { mf_classic_set_block_read(data, i, &block_tmp); blocks_read++; } } else { blocks_read++; } } FURI_LOG_D(TAG, "Read %d blocks out of %d", blocks_read, total_blocks); } while(false); do { if(blocks_read == total_blocks) break; if(!key_b_found) break; FURI_LOG_D(TAG, "Try to read blocks with key B"); key = nfc_util_bytes2num(sec_tr->key_b, sizeof(sec_tr->key_b)); furi_hal_nfc_sleep(); if(!mf_classic_auth(tx_rx, start_block, key, MfClassicKeyB, &crypto)) break; for(size_t i = start_block; i < start_block + total_blocks; i++) { if(!mf_classic_is_block_read(data, i)) { if(mf_classic_read_block(tx_rx, &crypto, i, &block_tmp)) { mf_classic_set_block_read(data, i, &block_tmp); blocks_read++; } } else { blocks_read++; } } FURI_LOG_D(TAG, "Read %d blocks out of %d", blocks_read, total_blocks); } while(false); } static bool mf_classic_read_sector_with_reader( FuriHalNfcTxRxContext* tx_rx, Crypto1* crypto, MfClassicSectorReader* sector_reader, MfClassicSector* sector) { furi_assert(tx_rx); furi_assert(sector_reader); furi_assert(sector); uint64_t key; MfClassicKey key_type; uint8_t first_block; bool sector_read = false; furi_hal_nfc_sleep(); do { // Activate card first_block = mf_classic_get_first_block_num_of_sector(sector_reader->sector_num); if(sector_reader->key_a != MF_CLASSIC_NO_KEY) { key = sector_reader->key_a; key_type = MfClassicKeyA; } else if(sector_reader->key_b != MF_CLASSIC_NO_KEY) { key = sector_reader->key_b; key_type = MfClassicKeyB; } else { break; } // Auth to first block in sector if(!mf_classic_auth(tx_rx, first_block, key, key_type, crypto)) break; sector->total_blocks = mf_classic_get_blocks_num_in_sector(sector_reader->sector_num); // Read blocks for(uint8_t i = 0; i < sector->total_blocks; i++) { mf_classic_read_block(tx_rx, crypto, first_block + i, §or->block[i]); } // Save sector keys in last block if(sector_reader->key_a != MF_CLASSIC_NO_KEY) { nfc_util_num2bytes( sector_reader->key_a, 6, §or->block[sector->total_blocks - 1].value[0]); } if(sector_reader->key_b != MF_CLASSIC_NO_KEY) { nfc_util_num2bytes( sector_reader->key_b, 6, §or->block[sector->total_blocks - 1].value[10]); } sector_read = true; } while(false); return sector_read; } uint8_t mf_classic_read_card( FuriHalNfcTxRxContext* tx_rx, MfClassicReader* reader, MfClassicData* data) { furi_assert(tx_rx); furi_assert(reader); furi_assert(data); uint8_t sectors_read = 0; data->type = reader->type; data->key_a_mask = 0; data->key_b_mask = 0; MfClassicSector temp_sector = {}; for(uint8_t i = 0; i < reader->sectors_to_read; i++) { if(mf_classic_read_sector_with_reader( tx_rx, &reader->crypto, &reader->sector_reader[i], &temp_sector)) { uint8_t first_block = mf_classic_get_first_block_num_of_sector(reader->sector_reader[i].sector_num); for(uint8_t j = 0; j < temp_sector.total_blocks; j++) { mf_classic_set_block_read(data, first_block + j, &temp_sector.block[j]); } if(reader->sector_reader[i].key_a != MF_CLASSIC_NO_KEY) { mf_classic_set_key_found( data, reader->sector_reader[i].sector_num, MfClassicKeyA, reader->sector_reader[i].key_a); } if(reader->sector_reader[i].key_b != MF_CLASSIC_NO_KEY) { mf_classic_set_key_found( data, reader->sector_reader[i].sector_num, MfClassicKeyB, reader->sector_reader[i].key_b); } sectors_read++; } } return sectors_read; } uint8_t mf_classic_update_card(FuriHalNfcTxRxContext* tx_rx, MfClassicData* data) { furi_assert(tx_rx); furi_assert(data); uint8_t sectors_read = 0; Crypto1 crypto = {}; uint8_t total_sectors = mf_classic_get_total_sectors_num(data->type); uint64_t key_a = 0; uint64_t key_b = 0; MfClassicSectorReader sec_reader = {}; MfClassicSector temp_sector = {}; for(size_t i = 0; i < total_sectors; i++) { MfClassicSectorTrailer* sec_tr = mf_classic_get_sector_trailer_by_sector(data, i); // Load key A if(mf_classic_is_key_found(data, i, MfClassicKeyA)) { sec_reader.key_a = nfc_util_bytes2num(sec_tr->key_a, 6); } else { sec_reader.key_a = MF_CLASSIC_NO_KEY; } // Load key B if(mf_classic_is_key_found(data, i, MfClassicKeyB)) { sec_reader.key_b = nfc_util_bytes2num(sec_tr->key_b, 6); } else { sec_reader.key_b = MF_CLASSIC_NO_KEY; } if((key_a != MF_CLASSIC_NO_KEY) || (key_b != MF_CLASSIC_NO_KEY)) { sec_reader.sector_num = i; if(mf_classic_read_sector_with_reader(tx_rx, &crypto, &sec_reader, &temp_sector)) { uint8_t first_block = mf_classic_get_first_block_num_of_sector(i); for(uint8_t j = 0; j < temp_sector.total_blocks; j++) { mf_classic_set_block_read(data, first_block + j, &temp_sector.block[j]); } sectors_read++; } } } return sectors_read; } void mf_crypto1_decrypt( Crypto1* crypto, uint8_t* encrypted_data, uint16_t encrypted_data_bits, uint8_t* decrypted_data) { if(encrypted_data_bits < 8) { uint8_t decrypted_byte = 0; decrypted_byte |= (crypto1_bit(crypto, 0, 0) ^ FURI_BIT(encrypted_data[0], 0)) << 0; decrypted_byte |= (crypto1_bit(crypto, 0, 0) ^ FURI_BIT(encrypted_data[0], 1)) << 1; decrypted_byte |= (crypto1_bit(crypto, 0, 0) ^ FURI_BIT(encrypted_data[0], 2)) << 2; decrypted_byte |= (crypto1_bit(crypto, 0, 0) ^ FURI_BIT(encrypted_data[0], 3)) << 3; decrypted_data[0] = decrypted_byte; } else { for(size_t i = 0; i < encrypted_data_bits / 8; i++) { decrypted_data[i] = crypto1_byte(crypto, 0, 0) ^ encrypted_data[i]; } } } void mf_crypto1_encrypt( Crypto1* crypto, uint8_t* keystream, uint8_t* plain_data, uint16_t plain_data_bits, uint8_t* encrypted_data, uint8_t* encrypted_parity) { if(plain_data_bits < 8) { encrypted_data[0] = 0; for(size_t i = 0; i < plain_data_bits; i++) { encrypted_data[0] |= (crypto1_bit(crypto, 0, 0) ^ FURI_BIT(plain_data[0], i)) << i; } } else { memset(encrypted_parity, 0, plain_data_bits / 8 + 1); for(uint8_t i = 0; i < plain_data_bits / 8; i++) { encrypted_data[i] = crypto1_byte(crypto, keystream ? keystream[i] : 0, 0) ^ plain_data[i]; encrypted_parity[i / 8] |= (((crypto1_filter(crypto->odd) ^ nfc_util_odd_parity8(plain_data[i])) & 0x01) << (7 - (i & 0x0007))); } } } bool mf_classic_emulator(MfClassicEmulator* emulator, FuriHalNfcTxRxContext* tx_rx) { furi_assert(emulator); furi_assert(tx_rx); bool command_processed = false; bool is_encrypted = false; uint8_t plain_data[MF_CLASSIC_MAX_DATA_SIZE]; MfClassicKey access_key = MfClassicKeyA; // Read command while(!command_processed) { if(!is_encrypted) { memcpy(plain_data, tx_rx->rx_data, tx_rx->rx_bits / 8); } else { if(!furi_hal_nfc_tx_rx(tx_rx, 300)) { FURI_LOG_D( TAG, "Error in tx rx. Tx :%d bits, Rx: %d bits", tx_rx->tx_bits, tx_rx->rx_bits); break; } mf_crypto1_decrypt(&emulator->crypto, tx_rx->rx_data, tx_rx->rx_bits, plain_data); } if(plain_data[0] == 0x50 && plain_data[1] == 0x00) { FURI_LOG_T(TAG, "Halt received"); furi_hal_nfc_listen_sleep(); command_processed = true; break; } else if(plain_data[0] == 0x60 || plain_data[0] == 0x61) { uint8_t block = plain_data[1]; uint64_t key = 0; uint8_t sector_trailer_block = mf_classic_get_sector_trailer_num_by_block(block); MfClassicSectorTrailer* sector_trailer = (MfClassicSectorTrailer*)emulator->data.block[sector_trailer_block].value; if(plain_data[0] == 0x60) { key = nfc_util_bytes2num(sector_trailer->key_a, 6); access_key = MfClassicKeyA; } else { key = nfc_util_bytes2num(sector_trailer->key_b, 6); access_key = MfClassicKeyB; } uint32_t nonce = prng_successor(DWT->CYCCNT, 32); uint8_t nt[4]; uint8_t nt_keystream[4]; nfc_util_num2bytes(nonce, 4, nt); nfc_util_num2bytes(nonce ^ emulator->cuid, 4, nt_keystream); crypto1_init(&emulator->crypto, key); if(!is_encrypted) { crypto1_word(&emulator->crypto, emulator->cuid ^ nonce, 0); memcpy(tx_rx->tx_data, nt, sizeof(nt)); tx_rx->tx_parity[0] = 0; for(size_t i = 0; i < sizeof(nt); i++) { tx_rx->tx_parity[0] |= nfc_util_odd_parity8(nt[i]) << (7 - i); } tx_rx->tx_bits = sizeof(nt) * 8; tx_rx->tx_rx_type = FuriHalNfcTxRxTransparent; } else { mf_crypto1_encrypt( &emulator->crypto, nt_keystream, nt, sizeof(nt) * 8, tx_rx->tx_data, tx_rx->tx_parity); tx_rx->tx_bits = sizeof(nt) * 8; tx_rx->tx_rx_type = FuriHalNfcTxRxTransparent; } if(!furi_hal_nfc_tx_rx(tx_rx, 500)) { FURI_LOG_E(TAG, "Error in NT exchange"); command_processed = true; break; } if(tx_rx->rx_bits != 64) { FURI_LOG_W(TAG, "Incorrect nr + ar"); command_processed = true; break; } uint32_t nr = nfc_util_bytes2num(tx_rx->rx_data, 4); uint32_t ar = nfc_util_bytes2num(&tx_rx->rx_data[4], 4); FURI_LOG_D( TAG, "%08x key%c block %d nt/nr/ar: %08x %08x %08x", emulator->cuid, access_key == MfClassicKeyA ? 'A' : 'B', sector_trailer_block, nonce, nr, ar); crypto1_word(&emulator->crypto, nr, 1); uint32_t cardRr = ar ^ crypto1_word(&emulator->crypto, 0, 0); if(cardRr != prng_successor(nonce, 64)) { FURI_LOG_T(TAG, "Wrong AUTH! %08X != %08X", cardRr, prng_successor(nonce, 64)); // Don't send NACK, as tag don't send it command_processed = true; break; } uint32_t ans = prng_successor(nonce, 96); uint8_t responce[4] = {}; nfc_util_num2bytes(ans, 4, responce); mf_crypto1_encrypt( &emulator->crypto, NULL, responce, sizeof(responce) * 8, tx_rx->tx_data, tx_rx->tx_parity); tx_rx->tx_bits = sizeof(responce) * 8; tx_rx->tx_rx_type = FuriHalNfcTxRxTransparent; is_encrypted = true; } else if(is_encrypted && plain_data[0] == 0x30) { uint8_t block = plain_data[1]; uint8_t block_data[18] = {}; memcpy(block_data, emulator->data.block[block].value, MF_CLASSIC_BLOCK_SIZE); if(mf_classic_is_sector_trailer(block)) { if(!mf_classic_is_allowed_access( emulator, block, access_key, MfClassicActionKeyARead)) { memset(block_data, 0, 6); } if(!mf_classic_is_allowed_access( emulator, block, access_key, MfClassicActionKeyBRead)) { memset(&block_data[10], 0, 6); } if(!mf_classic_is_allowed_access( emulator, block, access_key, MfClassicActionACRead)) { memset(&block_data[6], 0, 4); } } else { if(!mf_classic_is_allowed_access( emulator, block, access_key, MfClassicActionDataRead)) { memset(block_data, 0, 16); } } nfca_append_crc16(block_data, 16); mf_crypto1_encrypt( &emulator->crypto, NULL, block_data, sizeof(block_data) * 8, tx_rx->tx_data, tx_rx->tx_parity); tx_rx->tx_bits = 18 * 8; tx_rx->tx_rx_type = FuriHalNfcTxRxTransparent; } else if(is_encrypted && plain_data[0] == 0xA0) { uint8_t block = plain_data[1]; if(block > mf_classic_get_total_block_num(emulator->data.type)) { break; } // Send ACK uint8_t ack = 0x0A; mf_crypto1_encrypt(&emulator->crypto, NULL, &ack, 4, tx_rx->tx_data, tx_rx->tx_parity); tx_rx->tx_rx_type = FuriHalNfcTxRxTransparent; tx_rx->tx_bits = 4; if(!furi_hal_nfc_tx_rx(tx_rx, 300)) break; if(tx_rx->rx_bits != 18 * 8) break; mf_crypto1_decrypt(&emulator->crypto, tx_rx->rx_data, tx_rx->rx_bits, plain_data); uint8_t block_data[16] = {}; memcpy(block_data, emulator->data.block[block].value, MF_CLASSIC_BLOCK_SIZE); if(mf_classic_is_sector_trailer(block)) { if(mf_classic_is_allowed_access( emulator, block, access_key, MfClassicActionKeyAWrite)) { memcpy(block_data, plain_data, 6); } if(mf_classic_is_allowed_access( emulator, block, access_key, MfClassicActionKeyBWrite)) { memcpy(&block_data[10], &plain_data[10], 6); } if(mf_classic_is_allowed_access( emulator, block, access_key, MfClassicActionACWrite)) { memcpy(&block_data[6], &plain_data[6], 4); } } else { if(mf_classic_is_allowed_access( emulator, block, access_key, MfClassicActionDataWrite)) { memcpy(block_data, plain_data, MF_CLASSIC_BLOCK_SIZE); } } if(memcmp(block_data, emulator->data.block[block].value, MF_CLASSIC_BLOCK_SIZE)) { memcpy(emulator->data.block[block].value, block_data, MF_CLASSIC_BLOCK_SIZE); emulator->data_changed = true; } // Send ACK ack = 0x0A; mf_crypto1_encrypt(&emulator->crypto, NULL, &ack, 4, tx_rx->tx_data, tx_rx->tx_parity); tx_rx->tx_rx_type = FuriHalNfcTxRxTransparent; tx_rx->tx_bits = 4; } else { // Unknown command break; } } if(!command_processed) { // Send NACK uint8_t nack = 0x04; if(is_encrypted) { mf_crypto1_encrypt( &emulator->crypto, NULL, &nack, 4, tx_rx->tx_data, tx_rx->tx_parity); } else { tx_rx->tx_data[0] = nack; } tx_rx->tx_rx_type = FuriHalNfcTxRxTransparent; tx_rx->tx_bits = 4; furi_hal_nfc_tx_rx(tx_rx, 300); } return true; }