#include #include #include "mifare_ultralight.h" #include "nfc_util.h" #include #include "furi_hal_nfc.h" #define TAG "MfUltralight" // Algorithms from: https://github.com/RfidResearchGroup/proxmark3/blob/0f6061c16f072372b7d4d381911f1542afbc3a69/common/generator.c#L110 uint32_t mf_ul_pwdgen_xiaomi(FuriHalNfcDevData* data) { uint8_t hash[20]; mbedtls_sha1(data->uid, data->uid_len, hash); uint32_t pwd = 0; pwd |= (hash[hash[0] % 20]) << 24; pwd |= (hash[(hash[0] + 5) % 20]) << 16; pwd |= (hash[(hash[0] + 13) % 20]) << 8; pwd |= (hash[(hash[0] + 17) % 20]); return pwd; } uint32_t mf_ul_pwdgen_amiibo(FuriHalNfcDevData* data) { uint8_t* uid = data->uid; uint32_t pwd = 0; pwd |= (uid[1] ^ uid[3] ^ 0xAA) << 24; pwd |= (uid[2] ^ uid[4] ^ 0x55) << 16; pwd |= (uid[3] ^ uid[5] ^ 0xAA) << 8; pwd |= uid[4] ^ uid[6] ^ 0x55; return pwd; } bool mf_ul_check_card_type(uint8_t ATQA0, uint8_t ATQA1, uint8_t SAK) { if((ATQA0 == 0x44) && (ATQA1 == 0x00) && (SAK == 0x00)) { return true; } return false; } void mf_ul_reset(MfUltralightData* data) { furi_assert(data); data->type = MfUltralightTypeUnknown; memset(&data->version, 0, sizeof(MfUltralightVersion)); memset(data->signature, 0, sizeof(data->signature)); memset(data->counter, 0, sizeof(data->counter)); memset(data->tearing, 0, sizeof(data->tearing)); memset(data->data, 0, sizeof(data->data)); data->data_size = 0; data->data_read = 0; data->curr_authlim = 0; data->has_auth = false; } static MfUltralightFeatures mf_ul_get_features(MfUltralightType type) { switch(type) { case MfUltralightTypeUL11: case MfUltralightTypeUL21: return MfUltralightSupportFastRead | MfUltralightSupportCompatWrite | MfUltralightSupportReadCounter | MfUltralightSupportIncrCounter | MfUltralightSupportAuth | MfUltralightSupportSignature | MfUltralightSupportTearingFlags | MfUltralightSupportVcsl; case MfUltralightTypeNTAG213: case MfUltralightTypeNTAG215: case MfUltralightTypeNTAG216: return MfUltralightSupportFastRead | MfUltralightSupportCompatWrite | MfUltralightSupportReadCounter | MfUltralightSupportAuth | MfUltralightSupportSignature | MfUltralightSupportSingleCounter | MfUltralightSupportAsciiMirror; case MfUltralightTypeNTAGI2C1K: case MfUltralightTypeNTAGI2C2K: return MfUltralightSupportFastRead | MfUltralightSupportSectorSelect; case MfUltralightTypeNTAGI2CPlus1K: case MfUltralightTypeNTAGI2CPlus2K: return MfUltralightSupportFastRead | MfUltralightSupportAuth | MfUltralightSupportFastWrite | MfUltralightSupportSignature | MfUltralightSupportSectorSelect; case MfUltralightTypeNTAG203: return MfUltralightSupportCompatWrite | MfUltralightSupportCounterInMemory; default: // Assumed original MFUL 512-bit return MfUltralightSupportCompatWrite; } } static void mf_ul_set_default_version(MfUltralightReader* reader, MfUltralightData* data) { data->type = MfUltralightTypeUnknown; reader->pages_to_read = 16; } static void mf_ul_set_version_ntag203(MfUltralightReader* reader, MfUltralightData* data) { data->type = MfUltralightTypeNTAG203; reader->pages_to_read = 42; } bool mf_ultralight_read_version( FuriHalNfcTxRxContext* tx_rx, MfUltralightReader* reader, MfUltralightData* data) { bool version_read = false; do { FURI_LOG_D(TAG, "Reading version"); tx_rx->tx_data[0] = MF_UL_GET_VERSION_CMD; tx_rx->tx_bits = 8; tx_rx->tx_rx_type = FuriHalNfcTxRxTypeDefault; if(!furi_hal_nfc_tx_rx(tx_rx, 50) || tx_rx->rx_bits != 64) { FURI_LOG_D(TAG, "Failed reading version"); mf_ul_set_default_version(reader, data); furi_hal_nfc_sleep(); furi_hal_nfc_activate_nfca(300, NULL); break; } MfUltralightVersion* version = (MfUltralightVersion*)tx_rx->rx_data; data->version = *version; if(version->storage_size == 0x0B || version->storage_size == 0x00) { data->type = MfUltralightTypeUL11; reader->pages_to_read = 20; } else if(version->storage_size == 0x0E) { data->type = MfUltralightTypeUL21; reader->pages_to_read = 41; } else if(version->storage_size == 0x0F) { data->type = MfUltralightTypeNTAG213; reader->pages_to_read = 45; } else if(version->storage_size == 0x11) { data->type = MfUltralightTypeNTAG215; reader->pages_to_read = 135; } else if(version->prod_subtype == 5 && version->prod_ver_major == 2) { // NTAG I2C bool known = false; if(version->prod_ver_minor == 1) { if(version->storage_size == 0x13) { data->type = MfUltralightTypeNTAGI2C1K; reader->pages_to_read = 231; known = true; } else if(version->storage_size == 0x15) { data->type = MfUltralightTypeNTAGI2C2K; reader->pages_to_read = 485; known = true; } } else if(version->prod_ver_minor == 2) { if(version->storage_size == 0x13) { data->type = MfUltralightTypeNTAGI2CPlus1K; reader->pages_to_read = 236; known = true; } else if(version->storage_size == 0x15) { data->type = MfUltralightTypeNTAGI2CPlus2K; reader->pages_to_read = 492; known = true; } } if(!known) { mf_ul_set_default_version(reader, data); } } else if(version->storage_size == 0x13) { data->type = MfUltralightTypeNTAG216; reader->pages_to_read = 231; } else { mf_ul_set_default_version(reader, data); break; } version_read = true; } while(false); reader->supported_features = mf_ul_get_features(data->type); return version_read; } bool mf_ultralight_authenticate(FuriHalNfcTxRxContext* tx_rx, uint32_t key, uint16_t* pack) { bool authenticated = false; do { FURI_LOG_D(TAG, "Authenticating"); tx_rx->tx_data[0] = MF_UL_AUTH; nfc_util_num2bytes(key, 4, &tx_rx->tx_data[1]); tx_rx->tx_bits = 40; tx_rx->tx_rx_type = FuriHalNfcTxRxTypeDefault; if(!furi_hal_nfc_tx_rx(tx_rx, 50)) { FURI_LOG_D(TAG, "Tag did not respond to authentication"); break; } // PACK if(tx_rx->rx_bits < 2 * 8) { FURI_LOG_D(TAG, "Authentication failed"); break; } if(pack != NULL) { *pack = (tx_rx->rx_data[1] << 8) | tx_rx->rx_data[0]; } FURI_LOG_I(TAG, "Auth success. Password: %08X. PACK: %04X", key, *pack); authenticated = true; } while(false); return authenticated; } static int16_t mf_ultralight_page_addr_to_tag_addr(uint8_t sector, uint8_t page) { return sector * 256 + page; } static int16_t mf_ultralight_ntag_i2c_addr_lin_to_tag_1k( int16_t linear_address, uint8_t* sector, int16_t* valid_pages) { // 0 - 226: sector 0 // 227 - 228: config registers // 229 - 230: session registers if(linear_address > 230) { *valid_pages = 0; return -1; } else if(linear_address >= 229) { *sector = 3; *valid_pages = 2 - (linear_address - 229); return linear_address - 229 + 248; } else if(linear_address >= 227) { *sector = 0; *valid_pages = 2 - (linear_address - 227); return linear_address - 227 + 232; } else { *sector = 0; *valid_pages = 227 - linear_address; return linear_address; } } static int16_t mf_ultralight_ntag_i2c_addr_lin_to_tag_2k( int16_t linear_address, uint8_t* sector, int16_t* valid_pages) { // 0 - 255: sector 0 // 256 - 480: sector 1 // 481 - 482: config registers // 483 - 484: session registers if(linear_address > 484) { *valid_pages = 0; return -1; } else if(linear_address >= 483) { *sector = 3; *valid_pages = 2 - (linear_address - 483); return linear_address - 483 + 248; } else if(linear_address >= 481) { *sector = 1; *valid_pages = 2 - (linear_address - 481); return linear_address - 481 + 232; } else if(linear_address >= 256) { *sector = 1; *valid_pages = 225 - (linear_address - 256); return linear_address - 256; } else { *sector = 0; *valid_pages = 256 - linear_address; return linear_address; } } static int16_t mf_ultralight_ntag_i2c_addr_lin_to_tag_plus_1k( int16_t linear_address, uint8_t* sector, int16_t* valid_pages) { // 0 - 233: sector 0 + registers // 234 - 235: session registers if(linear_address > 235) { *valid_pages = 0; return -1; } else if(linear_address >= 234) { *sector = 0; *valid_pages = 2 - (linear_address - 234); return linear_address - 234 + 236; } else { *sector = 0; *valid_pages = 234 - linear_address; return linear_address; } } static int16_t mf_ultralight_ntag_i2c_addr_lin_to_tag_plus_2k( int16_t linear_address, uint8_t* sector, int16_t* valid_pages) { // 0 - 233: sector 0 + registers // 234 - 235: session registers // 236 - 491: sector 1 if(linear_address > 491) { *valid_pages = 0; return -1; } else if(linear_address >= 236) { *sector = 1; *valid_pages = 256 - (linear_address - 236); return linear_address - 236; } else if(linear_address >= 234) { *sector = 0; *valid_pages = 2 - (linear_address - 234); return linear_address - 234 + 236; } else { *sector = 0; *valid_pages = 234 - linear_address; return linear_address; } } static int16_t mf_ultralight_ntag_i2c_addr_lin_to_tag( MfUltralightData* data, MfUltralightReader* reader, int16_t linear_address, uint8_t* sector, int16_t* valid_pages) { switch(data->type) { case MfUltralightTypeNTAGI2C1K: return mf_ultralight_ntag_i2c_addr_lin_to_tag_1k(linear_address, sector, valid_pages); case MfUltralightTypeNTAGI2C2K: return mf_ultralight_ntag_i2c_addr_lin_to_tag_2k(linear_address, sector, valid_pages); case MfUltralightTypeNTAGI2CPlus1K: return mf_ultralight_ntag_i2c_addr_lin_to_tag_plus_1k(linear_address, sector, valid_pages); case MfUltralightTypeNTAGI2CPlus2K: return mf_ultralight_ntag_i2c_addr_lin_to_tag_plus_2k(linear_address, sector, valid_pages); default: *sector = 0xff; *valid_pages = reader->pages_to_read - linear_address; return linear_address; } } static int16_t mf_ultralight_ntag_i2c_addr_tag_to_lin_1k(uint8_t page, uint8_t sector, uint16_t* valid_pages) { bool valid = false; int16_t translated_page; if(sector == 0) { if(page <= 226) { *valid_pages = 227 - page; translated_page = page; valid = true; } else if(page >= 232 && page <= 233) { *valid_pages = 2 - (page - 232); translated_page = page - 232 + 227; valid = true; } } else if(sector == 3) { if(page >= 248 && page <= 249) { *valid_pages = 2 - (page - 248); translated_page = page - 248 + 229; valid = true; } } if(!valid) { *valid_pages = 0; translated_page = -1; } return translated_page; } static int16_t mf_ultralight_ntag_i2c_addr_tag_to_lin_2k(uint8_t page, uint8_t sector, uint16_t* valid_pages) { bool valid = false; int16_t translated_page; if(sector == 0) { *valid_pages = 256 - page; translated_page = page; valid = true; } else if(sector == 1) { if(page <= 224) { *valid_pages = 225 - page; translated_page = 256 + page; valid = true; } else if(page >= 232 && page <= 233) { *valid_pages = 2 - (page - 232); translated_page = page - 232 + 481; valid = true; } } else if(sector == 3) { if(page >= 248 && page <= 249) { *valid_pages = 2 - (page - 248); translated_page = page - 248 + 483; valid = true; } } if(!valid) { *valid_pages = 0; translated_page = -1; } return translated_page; } static int16_t mf_ultralight_ntag_i2c_addr_tag_to_lin_plus_1k( uint8_t page, uint8_t sector, uint16_t* valid_pages) { bool valid = false; int16_t translated_page; if(sector == 0) { if(page <= 233) { *valid_pages = 234 - page; translated_page = page; valid = true; } else if(page >= 236 && page <= 237) { *valid_pages = 2 - (page - 236); translated_page = page - 236 + 234; valid = true; } } else if(sector == 3) { if(page >= 248 && page <= 249) { *valid_pages = 2 - (page - 248); translated_page = page - 248 + 234; valid = true; } } if(!valid) { *valid_pages = 0; translated_page = -1; } return translated_page; } static int16_t mf_ultralight_ntag_i2c_addr_tag_to_lin_plus_2k( uint8_t page, uint8_t sector, uint16_t* valid_pages) { bool valid = false; int16_t translated_page; if(sector == 0) { if(page <= 233) { *valid_pages = 234 - page; translated_page = page; valid = true; } else if(page >= 236 && page <= 237) { *valid_pages = 2 - (page - 236); translated_page = page - 236 + 234; valid = true; } } else if(sector == 1) { *valid_pages = 256 - page; translated_page = page + 236; valid = true; } else if(sector == 3) { if(page >= 248 && page <= 249) { *valid_pages = 2 - (page - 248); translated_page = page - 248 + 234; valid = true; } } if(!valid) { *valid_pages = 0; translated_page = -1; } return translated_page; } static int16_t mf_ultralight_ntag_i2c_addr_tag_to_lin( MfUltralightData* data, uint8_t page, uint8_t sector, uint16_t* valid_pages) { switch(data->type) { case MfUltralightTypeNTAGI2C1K: return mf_ultralight_ntag_i2c_addr_tag_to_lin_1k(page, sector, valid_pages); case MfUltralightTypeNTAGI2C2K: return mf_ultralight_ntag_i2c_addr_tag_to_lin_2k(page, sector, valid_pages); case MfUltralightTypeNTAGI2CPlus1K: return mf_ultralight_ntag_i2c_addr_tag_to_lin_plus_1k(page, sector, valid_pages); case MfUltralightTypeNTAGI2CPlus2K: return mf_ultralight_ntag_i2c_addr_tag_to_lin_plus_2k(page, sector, valid_pages); default: *valid_pages = data->data_size / 4 - page; return page; } } MfUltralightConfigPages* mf_ultralight_get_config_pages(MfUltralightData* data) { if(data->type >= MfUltralightTypeUL11 && data->type <= MfUltralightTypeNTAG216) { return (MfUltralightConfigPages*)&data->data[data->data_size - 4 * 4]; } else if( data->type >= MfUltralightTypeNTAGI2CPlus1K && data->type <= MfUltralightTypeNTAGI2CPlus2K) { return (MfUltralightConfigPages*)&data->data[0xe3 * 4]; } else { return NULL; } } static uint16_t mf_ultralight_calc_auth_count(MfUltralightData* data) { if(mf_ul_get_features(data->type) & MfUltralightSupportAuth) { MfUltralightConfigPages* config = mf_ultralight_get_config_pages(data); uint16_t scaled_authlim = config->access.authlim; // NTAG I2C Plus uses 2^AUTHLIM attempts rather than the direct number if(scaled_authlim > 0 && data->type >= MfUltralightTypeNTAGI2CPlus1K && data->type <= MfUltralightTypeNTAGI2CPlus2K) { scaled_authlim = 1 << scaled_authlim; } return scaled_authlim; } return 0; } // NTAG21x will NAK if NFC_CNT_EN unset, so preempt static bool mf_ultralight_should_read_counters(MfUltralightData* data) { if(data->type < MfUltralightTypeNTAG213 || data->type > MfUltralightTypeNTAG216) return true; MfUltralightConfigPages* config = mf_ultralight_get_config_pages(data); return config->access.nfc_cnt_en; } static bool mf_ultralight_sector_select(FuriHalNfcTxRxContext* tx_rx, uint8_t sector) { FURI_LOG_D(TAG, "Selecting sector %u", sector); tx_rx->tx_data[0] = MF_UL_SECTOR_SELECT; tx_rx->tx_data[1] = 0xff; tx_rx->tx_bits = 16; tx_rx->tx_rx_type = FuriHalNfcTxRxTypeDefault; if(!furi_hal_nfc_tx_rx(tx_rx, 50)) { FURI_LOG_D(TAG, "Failed to issue sector select command"); return false; } tx_rx->tx_data[0] = sector; tx_rx->tx_data[1] = 0x00; tx_rx->tx_data[2] = 0x00; tx_rx->tx_data[3] = 0x00; tx_rx->tx_bits = 32; tx_rx->tx_rx_type = FuriHalNfcTxRxTypeDefault; // This is NOT a typo! The tag ACKs by not sending a response within 1ms. if(furi_hal_nfc_tx_rx(tx_rx, 20)) { // TODO: what gets returned when an actual NAK is received? FURI_LOG_D(TAG, "Sector %u select NAK'd", sector); return false; } return true; } bool mf_ultralight_read_pages_direct( FuriHalNfcTxRxContext* tx_rx, uint8_t start_index, uint8_t* data) { FURI_LOG_D(TAG, "Reading pages %d - %d", start_index, start_index + 3); tx_rx->tx_data[0] = MF_UL_READ_CMD; tx_rx->tx_data[1] = start_index; tx_rx->tx_bits = 16; tx_rx->tx_rx_type = FuriHalNfcTxRxTypeDefault; if(!furi_hal_nfc_tx_rx(tx_rx, 50) || tx_rx->rx_bits < 16 * 8) { FURI_LOG_D(TAG, "Failed to read pages %d - %d", start_index, start_index + 3); return false; } memcpy(data, tx_rx->rx_data, 16); return true; } bool mf_ultralight_read_pages( FuriHalNfcTxRxContext* tx_rx, MfUltralightReader* reader, MfUltralightData* data) { uint8_t pages_read_cnt = 0; uint8_t curr_sector_index = 0xff; reader->pages_read = 0; for(size_t i = 0; i < reader->pages_to_read; i += pages_read_cnt) { uint8_t tag_sector; int16_t valid_pages; int16_t tag_page = mf_ultralight_ntag_i2c_addr_lin_to_tag( data, reader, (int16_t)i, &tag_sector, &valid_pages); furi_assert(tag_page != -1); if(curr_sector_index != tag_sector) { if(!mf_ultralight_sector_select(tx_rx, tag_sector)) return false; curr_sector_index = tag_sector; } FURI_LOG_D(TAG, "Reading pages %d - %d", i, i + (valid_pages > 4 ? 4 : valid_pages) - 1); tx_rx->tx_data[0] = MF_UL_READ_CMD; tx_rx->tx_data[1] = tag_page; tx_rx->tx_bits = 16; tx_rx->tx_rx_type = FuriHalNfcTxRxTypeDefault; if(!furi_hal_nfc_tx_rx(tx_rx, 50) || tx_rx->rx_bits < 16 * 8) { FURI_LOG_D( TAG, "Failed to read pages %d - %d", i, i + (valid_pages > 4 ? 4 : valid_pages) - 1); break; } if(valid_pages > 4) { pages_read_cnt = 4; } else { pages_read_cnt = valid_pages; } reader->pages_read += pages_read_cnt; memcpy(&data->data[i * 4], tx_rx->rx_data, pages_read_cnt * 4); } data->data_size = reader->pages_to_read * 4; data->data_read = reader->pages_read * 4; return reader->pages_read > 0; } bool mf_ultralight_fast_read_pages( FuriHalNfcTxRxContext* tx_rx, MfUltralightReader* reader, MfUltralightData* data) { uint8_t curr_sector_index = 0xff; reader->pages_read = 0; while(reader->pages_read < reader->pages_to_read) { uint8_t tag_sector; int16_t valid_pages; int16_t tag_page = mf_ultralight_ntag_i2c_addr_lin_to_tag( data, reader, reader->pages_read, &tag_sector, &valid_pages); furi_assert(tag_page != -1); if(curr_sector_index != tag_sector) { if(!mf_ultralight_sector_select(tx_rx, tag_sector)) return false; curr_sector_index = tag_sector; } FURI_LOG_D( TAG, "Reading pages %d - %d", reader->pages_read, reader->pages_read + valid_pages - 1); tx_rx->tx_data[0] = MF_UL_FAST_READ_CMD; tx_rx->tx_data[1] = tag_page; tx_rx->tx_data[2] = valid_pages - 1; tx_rx->tx_bits = 24; tx_rx->tx_rx_type = FuriHalNfcTxRxTypeDefault; if(furi_hal_nfc_tx_rx(tx_rx, 50)) { memcpy(&data->data[reader->pages_read * 4], tx_rx->rx_data, valid_pages * 4); reader->pages_read += valid_pages; data->data_size = reader->pages_read * 4; } else { FURI_LOG_D( TAG, "Failed to read pages %d - %d", reader->pages_read, reader->pages_read + valid_pages - 1); break; } } return reader->pages_read == reader->pages_to_read; } bool mf_ultralight_read_signature(FuriHalNfcTxRxContext* tx_rx, MfUltralightData* data) { bool signature_read = false; FURI_LOG_D(TAG, "Reading signature"); tx_rx->tx_data[0] = MF_UL_READ_SIG; tx_rx->tx_data[1] = 0; tx_rx->tx_bits = 16; tx_rx->tx_rx_type = FuriHalNfcTxRxTypeDefault; if(furi_hal_nfc_tx_rx(tx_rx, 50)) { memcpy(data->signature, tx_rx->rx_data, sizeof(data->signature)); signature_read = true; } else { FURI_LOG_D(TAG, "Failed redaing signature"); } return signature_read; } bool mf_ultralight_read_counters(FuriHalNfcTxRxContext* tx_rx, MfUltralightData* data) { uint8_t counter_read = 0; FURI_LOG_D(TAG, "Reading counters"); bool is_single_counter = (mf_ul_get_features(data->type) & MfUltralightSupportSingleCounter) != 0; for(size_t i = is_single_counter ? 2 : 0; i < 3; i++) { tx_rx->tx_data[0] = MF_UL_READ_CNT; tx_rx->tx_data[1] = i; tx_rx->tx_bits = 16; tx_rx->tx_rx_type = FuriHalNfcTxRxTypeDefault; if(!furi_hal_nfc_tx_rx(tx_rx, 50)) { FURI_LOG_D(TAG, "Failed to read %d counter", i); break; } data->counter[i] = (tx_rx->rx_data[2] << 16) | (tx_rx->rx_data[1] << 8) | tx_rx->rx_data[0]; counter_read++; } return counter_read == (is_single_counter ? 1 : 3); } bool mf_ultralight_read_tearing_flags(FuriHalNfcTxRxContext* tx_rx, MfUltralightData* data) { uint8_t flag_read = 0; FURI_LOG_D(TAG, "Reading tearing flags"); for(size_t i = 0; i < 3; i++) { tx_rx->tx_data[0] = MF_UL_CHECK_TEARING; tx_rx->rx_data[1] = i; tx_rx->tx_bits = 16; tx_rx->tx_rx_type = FuriHalNfcTxRxTypeDefault; if(!furi_hal_nfc_tx_rx(tx_rx, 50)) { FURI_LOG_D(TAG, "Failed to read %d tearing flag", i); break; } data->tearing[i] = tx_rx->rx_data[0]; flag_read++; } return flag_read == 2; } bool mf_ul_read_card( FuriHalNfcTxRxContext* tx_rx, MfUltralightReader* reader, MfUltralightData* data) { furi_assert(tx_rx); furi_assert(reader); furi_assert(data); bool card_read = false; // Read Mifare Ultralight version if(mf_ultralight_read_version(tx_rx, reader, data)) { if(reader->supported_features & MfUltralightSupportSignature) { // Read Signature mf_ultralight_read_signature(tx_rx, data); } } else { // No GET_VERSION command, check for NTAG203 by reading last page (41) uint8_t dummy[16]; if(mf_ultralight_read_pages_direct(tx_rx, 41, dummy)) { mf_ul_set_version_ntag203(reader, data); reader->supported_features = mf_ul_get_features(data->type); } else { // We're really an original Mifare Ultralight, reset tag for safety furi_hal_nfc_sleep(); furi_hal_nfc_activate_nfca(300, NULL); } } card_read = mf_ultralight_read_pages(tx_rx, reader, data); if(card_read) { if(reader->supported_features & MfUltralightSupportReadCounter && mf_ultralight_should_read_counters(data)) { mf_ultralight_read_counters(tx_rx, data); } if(reader->supported_features & MfUltralightSupportTearingFlags) { mf_ultralight_read_tearing_flags(tx_rx, data); } data->curr_authlim = 0; } return card_read; } static void mf_ul_protect_auth_data_on_read_command_i2c( uint8_t* tx_buff, uint8_t start_page, uint8_t end_page, MfUltralightEmulator* emulator) { if(emulator->data.type >= MfUltralightTypeNTAGI2CPlus1K) { // Blank out PWD and PACK if(start_page <= 229 && end_page >= 229) { uint16_t offset = (229 - start_page) * 4; uint8_t count = 4; if(end_page >= 230) count += 2; memset(&tx_buff[offset], 0, count); } // Handle AUTH0 for sector 0 if(!emulator->auth_success) { if(emulator->config_cache.access.prot) { uint8_t auth0 = emulator->config_cache.auth0; if(auth0 < end_page) { // start_page is always < auth0; otherwise is NAK'd already uint8_t page_offset = auth0 - start_page; uint8_t page_count = end_page - auth0; memset(&tx_buff[page_offset * 4], 0, page_count * 4); } } } } } static void mf_ul_ntag_i2c_fill_cross_area_read( uint8_t* tx_buff, uint8_t start_page, uint8_t end_page, MfUltralightEmulator* emulator) { // For copying config or session registers in fast read int16_t tx_page_offset; int16_t data_page_offset; uint8_t page_length; bool apply = false; MfUltralightType type = emulator->data.type; if(emulator->curr_sector == 0) { if(type == MfUltralightTypeNTAGI2C1K) { if(start_page <= 233 && end_page >= 232) { tx_page_offset = start_page - 232; data_page_offset = 227; page_length = 2; apply = true; } } else if(type == MfUltralightTypeNTAGI2CPlus1K || type == MfUltralightTypeNTAGI2CPlus2K) { if(start_page <= 237 && end_page >= 236) { tx_page_offset = start_page - 236; data_page_offset = 234; page_length = 2; apply = true; } } } else if(emulator->curr_sector == 1) { if(type == MfUltralightTypeNTAGI2C2K) { if(start_page <= 233 && end_page >= 232) { tx_page_offset = start_page - 232; data_page_offset = 483; page_length = 2; apply = true; } } } if(apply) { while(tx_page_offset < 0 && page_length > 0) { ++tx_page_offset; ++data_page_offset; --page_length; } memcpy( &tx_buff[tx_page_offset * 4], &emulator->data.data[data_page_offset * 4], page_length * 4); } } static bool mf_ul_check_auth(MfUltralightEmulator* emulator, uint8_t start_page, bool is_write) { if(!emulator->auth_success) { if(start_page >= emulator->config_cache.auth0 && (emulator->config_cache.access.prot || is_write)) return false; } if(is_write && emulator->config_cache.access.cfglck) { uint16_t config_start_page = emulator->page_num - 4; if(start_page == config_start_page || start_page == config_start_page + 1) return false; } return true; } static bool mf_ul_ntag_i2c_plus_check_auth( MfUltralightEmulator* emulator, uint8_t start_page, bool is_write) { if(!emulator->auth_success) { // Check NFC_PROT if(emulator->curr_sector == 0 && (emulator->config_cache.access.prot || is_write)) { if(start_page >= emulator->config_cache.auth0) return false; } else if(emulator->curr_sector == 1) { // We don't have to specifically check for type because this is done // by address translator uint8_t pt_i2c = emulator->data.data[231 * 4]; // Check 2K_PROT if(pt_i2c & 0x08) return false; } } if(emulator->curr_sector == 1) { // Check NFC_DIS_SEC1 if(emulator->config_cache.access.nfc_dis_sec1) return false; } return true; } static int16_t mf_ul_get_dynamic_lock_page_addr(MfUltralightData* data) { switch(data->type) { case MfUltralightTypeNTAG203: return 0x28; case MfUltralightTypeUL21: case MfUltralightTypeNTAG213: case MfUltralightTypeNTAG215: case MfUltralightTypeNTAG216: return data->data_size / 4 - 5; case MfUltralightTypeNTAGI2C1K: case MfUltralightTypeNTAGI2CPlus1K: case MfUltralightTypeNTAGI2CPlus2K: return 0xe2; case MfUltralightTypeNTAGI2C2K: return 0x1e0; default: return -1; // No dynamic lock bytes } } // Returns true if page not locked // write_page is tag address static bool mf_ul_check_lock(MfUltralightEmulator* emulator, int16_t write_page) { if(write_page < 2) return false; // Page 0-1 is always locked if(write_page == 2) return true; // Page 2 does not have a lock flag // Check static lock bytes if(write_page <= 15) { uint16_t static_lock_bytes = emulator->data.data[10] | (emulator->data.data[11] << 8); return (static_lock_bytes & (1 << write_page)) == 0; } // Check dynamic lock bytes // Check max page switch(emulator->data.type) { case MfUltralightTypeNTAG203: // Counter page can be locked and is after dynamic locks if(write_page == 40) return true; break; case MfUltralightTypeUL21: case MfUltralightTypeNTAG213: case MfUltralightTypeNTAG215: case MfUltralightTypeNTAG216: if(write_page >= emulator->page_num - 5) return true; break; case MfUltralightTypeNTAGI2C1K: case MfUltralightTypeNTAGI2CPlus1K: if(write_page > 225) return true; break; case MfUltralightTypeNTAGI2C2K: if(write_page > 479) return true; break; case MfUltralightTypeNTAGI2CPlus2K: if(write_page >= 226 && write_page <= 255) return true; if(write_page >= 512) return true; break; default: furi_crash("Unknown MFUL"); return true; } int16_t dynamic_lock_index = mf_ul_get_dynamic_lock_page_addr(&emulator->data); if(dynamic_lock_index == -1) return true; // Run address through converter because NTAG I2C 2K is special uint16_t valid_pages; // unused dynamic_lock_index = mf_ultralight_ntag_i2c_addr_tag_to_lin( &emulator->data, dynamic_lock_index & 0xff, dynamic_lock_index >> 8, &valid_pages) * 4; uint16_t dynamic_lock_bytes = emulator->data.data[dynamic_lock_index] | (emulator->data.data[dynamic_lock_index + 1] << 8); uint8_t shift; switch(emulator->data.type) { // low byte LSB range, MSB range case MfUltralightTypeNTAG203: if(write_page >= 16 && write_page <= 27) shift = (write_page - 16) / 4 + 1; else if(write_page >= 28 && write_page <= 39) shift = (write_page - 28) / 4 + 5; else if(write_page == 41) shift = 12; else { furi_crash("Unknown MFUL"); } break; case MfUltralightTypeUL21: case MfUltralightTypeNTAG213: // 16-17, 30-31 shift = (write_page - 16) / 2; break; case MfUltralightTypeNTAG215: case MfUltralightTypeNTAG216: case MfUltralightTypeNTAGI2C1K: case MfUltralightTypeNTAGI2CPlus1K: // 16-31, 128-129 // 16-31, 128-143 shift = (write_page - 16) / 16; break; case MfUltralightTypeNTAGI2C2K: // 16-47, 240-271 shift = (write_page - 16) / 32; break; case MfUltralightTypeNTAGI2CPlus2K: // 16-47, 256-271 if(write_page >= 208 && write_page <= 225) shift = 6; else if(write_page >= 256 && write_page <= 271) shift = 7; else shift = (write_page - 16) / 32; break; default: furi_crash("Unknown MFUL"); break; } return (dynamic_lock_bytes & (1 << shift)) == 0; } static void mf_ul_make_ascii_mirror(MfUltralightEmulator* emulator, FuriString* str) { // Locals to improve readability uint8_t mirror_page = emulator->config->mirror_page; uint8_t mirror_byte = emulator->config->mirror.mirror_byte; MfUltralightMirrorConf mirror_conf = emulator->config_cache.mirror.mirror_conf; uint16_t last_user_page_index = emulator->page_num - 6; bool uid_printed = false; if(mirror_conf == MfUltralightMirrorUid || mirror_conf == MfUltralightMirrorUidCounter) { // UID range check if(mirror_page < 4 || mirror_page > last_user_page_index - 3 || (mirror_page == last_user_page_index - 3 && mirror_byte > 2)) { if(mirror_conf == MfUltralightMirrorUid) return; // NTAG21x has the peculiar behavior when UID+counter selected, if UID does not fit but // counter will fit, it will actually mirror the counter furi_string_cat(str, " "); } else { for(int i = 0; i < 3; ++i) { furi_string_cat_printf(str, "%02X", emulator->data.data[i]); } // Skip BCC0 for(int i = 4; i < 8; ++i) { furi_string_cat_printf(str, "%02X", emulator->data.data[i]); } uid_printed = true; } uint16_t next_byte_offset = mirror_page * 4 + mirror_byte + 14; if(mirror_conf == MfUltralightMirrorUidCounter) ++next_byte_offset; mirror_page = next_byte_offset / 4; mirror_byte = next_byte_offset % 4; } if(mirror_conf == MfUltralightMirrorCounter || mirror_conf == MfUltralightMirrorUidCounter) { // Counter is only printed if counter enabled if(emulator->config_cache.access.nfc_cnt_en) { // Counter protection check if(emulator->config_cache.access.nfc_cnt_pwd_prot && !emulator->auth_success) return; // Counter range check if(mirror_page < 4) return; if(mirror_page > last_user_page_index - 1) return; if(mirror_page == last_user_page_index - 1 && mirror_byte > 2) return; if(mirror_conf == MfUltralightMirrorUidCounter) furi_string_cat(str, uid_printed ? "x" : " "); furi_string_cat_printf(str, "%06X", emulator->data.counter[2]); } } } static void mf_ul_increment_single_counter(MfUltralightEmulator* emulator) { if(!emulator->read_counter_incremented && emulator->config_cache.access.nfc_cnt_en) { if(emulator->data.counter[2] < 0xFFFFFF) { ++emulator->data.counter[2]; emulator->data_changed = true; } emulator->read_counter_incremented = true; } } static bool mf_ul_emulate_ntag203_counter_write(MfUltralightEmulator* emulator, uint8_t* page_buff) { // We'll reuse the existing counters for other NTAGs as staging // Counter 0 stores original value, data is new value uint32_t counter_value; if(emulator->data.tearing[0] == MF_UL_TEARING_FLAG_DEFAULT) { counter_value = emulator->data.data[MF_UL_NTAG203_COUNTER_PAGE * 4] | (emulator->data.data[MF_UL_NTAG203_COUNTER_PAGE * 4 + 1] << 8); } else { // We've had a reset here, so load from original value counter_value = emulator->data.counter[0]; } // Although the datasheet says increment by 0 is always possible, this is not the case on // an actual tag. If the counter is at 0xFFFF, any writes are locked out. if(counter_value == 0xFFFF) return false; uint32_t increment = page_buff[0] | (page_buff[1] << 8); if(counter_value == 0) { counter_value = increment; } else { // Per datasheet specifying > 0x000F is supposed to NAK, but actual tag doesn't increment &= 0x000F; if(counter_value + increment > 0xFFFF) return false; counter_value += increment; } // Commit to new value counter emulator->data.data[MF_UL_NTAG203_COUNTER_PAGE * 4] = (uint8_t)counter_value; emulator->data.data[MF_UL_NTAG203_COUNTER_PAGE * 4 + 1] = (uint8_t)(counter_value >> 8); emulator->data.tearing[0] = MF_UL_TEARING_FLAG_DEFAULT; if(counter_value == 0xFFFF) { // Tag will lock out counter if final number is 0xFFFF, even if you try to roll it back emulator->data.counter[1] = 0xFFFF; } emulator->data_changed = true; return true; } static void mf_ul_emulate_write( MfUltralightEmulator* emulator, int16_t tag_addr, int16_t write_page, uint8_t* page_buff) { // Assumption: all access checks have been completed if(tag_addr == 2) { // Handle static locks uint16_t orig_static_locks = emulator->data.data[write_page * 4 + 2] | (emulator->data.data[write_page * 4 + 3] << 8); uint16_t new_static_locks = page_buff[2] | (page_buff[3] << 8); if(orig_static_locks & 1) new_static_locks &= ~0x08; if(orig_static_locks & 2) new_static_locks &= ~0xF0; if(orig_static_locks & 4) new_static_locks &= 0xFF; new_static_locks |= orig_static_locks; page_buff[0] = emulator->data.data[write_page * 4]; page_buff[1] = emulator->data.data[write_page * 4 + 1]; page_buff[2] = new_static_locks & 0xff; page_buff[3] = new_static_locks >> 8; } else if(tag_addr == 3) { // Handle OTP/capability container *(uint32_t*)page_buff |= *(uint32_t*)&emulator->data.data[write_page * 4]; } else if(tag_addr == mf_ul_get_dynamic_lock_page_addr(&emulator->data)) { // Handle dynamic locks if(emulator->data.type == MfUltralightTypeNTAG203) { // NTAG203 lock bytes are a bit different from the others uint8_t orig_page_lock_byte = emulator->data.data[write_page * 4]; uint8_t orig_cnt_lock_byte = emulator->data.data[write_page * 4 + 1]; uint8_t new_page_lock_byte = page_buff[0]; uint8_t new_cnt_lock_byte = page_buff[1]; if(orig_page_lock_byte & 0x01) // Block lock bits 1-3 new_page_lock_byte &= ~0x0E; if(orig_page_lock_byte & 0x10) // Block lock bits 5-7 new_page_lock_byte &= ~0xE0; for(uint8_t i = 0; i < 4; ++i) { if(orig_cnt_lock_byte & (1 << i)) // Block lock counter bit new_cnt_lock_byte &= ~(1 << (4 + i)); } new_page_lock_byte |= orig_page_lock_byte; new_cnt_lock_byte |= orig_cnt_lock_byte; page_buff[0] = new_page_lock_byte; page_buff[1] = new_cnt_lock_byte; } else { uint16_t orig_locks = emulator->data.data[write_page * 4] | (emulator->data.data[write_page * 4 + 1] << 8); uint8_t orig_block_locks = emulator->data.data[write_page * 4 + 2]; uint16_t new_locks = page_buff[0] | (page_buff[1] << 8); uint8_t new_block_locks = page_buff[2]; int block_lock_count; switch(emulator->data.type) { case MfUltralightTypeUL21: block_lock_count = 5; break; case MfUltralightTypeNTAG213: block_lock_count = 6; break; case MfUltralightTypeNTAG215: block_lock_count = 4; break; case MfUltralightTypeNTAG216: case MfUltralightTypeNTAGI2C1K: case MfUltralightTypeNTAGI2CPlus1K: block_lock_count = 7; break; case MfUltralightTypeNTAGI2C2K: case MfUltralightTypeNTAGI2CPlus2K: block_lock_count = 8; break; default: furi_crash("Unknown MFUL"); break; } for(int i = 0; i < block_lock_count; ++i) { if(orig_block_locks & (1 << i)) new_locks &= ~(3 << (2 * i)); } new_locks |= orig_locks; new_block_locks |= orig_block_locks; page_buff[0] = new_locks & 0xff; page_buff[1] = new_locks >> 8; page_buff[2] = new_block_locks; if(emulator->data.type >= MfUltralightTypeUL21 && emulator->data.type <= MfUltralightTypeNTAG216) page_buff[3] = MF_UL_TEARING_FLAG_DEFAULT; else page_buff[3] = 0; } } memcpy(&emulator->data.data[write_page * 4], page_buff, 4); emulator->data_changed = true; } void mf_ul_reset_emulation(MfUltralightEmulator* emulator, bool is_power_cycle) { emulator->curr_sector = 0; emulator->ntag_i2c_plus_sector3_lockout = false; emulator->auth_success = false; if(is_power_cycle) { if(emulator->config != NULL) emulator->config_cache = *emulator->config; if(emulator->supported_features & MfUltralightSupportSingleCounter) { emulator->read_counter_incremented = false; } if(emulator->data.type == MfUltralightTypeNTAG203) { // Apply lockout if counter ever reached 0xFFFF if(emulator->data.counter[1] == 0xFFFF) { emulator->data.data[MF_UL_NTAG203_COUNTER_PAGE * 4] = 0xFF; emulator->data.data[MF_UL_NTAG203_COUNTER_PAGE * 4 + 1] = 0xFF; } // Copy original counter value from data emulator->data.counter[0] = emulator->data.data[MF_UL_NTAG203_COUNTER_PAGE * 4] | (emulator->data.data[MF_UL_NTAG203_COUNTER_PAGE * 4 + 1] << 8); } } else { if(emulator->config != NULL) { // ACCESS (less CFGLCK) and AUTH0 are updated when reactivated // MIRROR_CONF is not; don't know about STRG_MOD_EN, but we're not using that anyway emulator->config_cache.access.value = (emulator->config->access.value & 0xBF) | (emulator->config_cache.access.value & 0x40); emulator->config_cache.auth0 = emulator->config->auth0; } } if(emulator->data.type == MfUltralightTypeNTAG203) { // Mark counter as dirty emulator->data.tearing[0] = 0; } } void mf_ul_prepare_emulation(MfUltralightEmulator* emulator, MfUltralightData* data) { FURI_LOG_D(TAG, "Prepare emulation"); emulator->data = *data; emulator->supported_features = mf_ul_get_features(data->type); emulator->config = mf_ultralight_get_config_pages(&emulator->data); emulator->page_num = emulator->data.data_size / 4; emulator->data_changed = false; emulator->comp_write_cmd_started = false; emulator->sector_select_cmd_started = false; mf_ul_reset_emulation(emulator, true); } bool mf_ul_prepare_emulation_response( uint8_t* buff_rx, uint16_t buff_rx_len, uint8_t* buff_tx, uint16_t* buff_tx_len, uint32_t* data_type, void* context) { furi_assert(context); MfUltralightEmulator* emulator = context; uint16_t tx_bytes = 0; uint16_t tx_bits = 0; bool command_parsed = false; bool send_ack = false; bool respond_nothing = false; bool reset_idle = false; #ifdef FURI_DEBUG FuriString* debug_buf; debug_buf = furi_string_alloc(); for(int i = 0; i < (buff_rx_len + 7) / 8; ++i) { furi_string_cat_printf(debug_buf, "%02x ", buff_rx[i]); } furi_string_trim(debug_buf); FURI_LOG_T(TAG, "Emu RX (%d): %s", buff_rx_len, furi_string_get_cstr(debug_buf)); furi_string_reset(debug_buf); #endif // Check composite commands if(emulator->comp_write_cmd_started) { if(buff_rx_len == 16 * 8) { if(emulator->data.type == MfUltralightTypeNTAG203 && emulator->comp_write_page_addr == MF_UL_NTAG203_COUNTER_PAGE) { send_ack = mf_ul_emulate_ntag203_counter_write(emulator, buff_rx); command_parsed = send_ack; } else { mf_ul_emulate_write( emulator, emulator->comp_write_page_addr, emulator->comp_write_page_addr, buff_rx); send_ack = true; command_parsed = true; } } emulator->comp_write_cmd_started = false; } else if(emulator->sector_select_cmd_started) { if(buff_rx_len == 4 * 8) { if(buff_rx[0] <= 0xFE) { emulator->curr_sector = buff_rx[0] > 3 ? 0 : buff_rx[0]; emulator->ntag_i2c_plus_sector3_lockout = false; command_parsed = true; respond_nothing = true; FURI_LOG_D(TAG, "Changing sector to %d", emulator->curr_sector); } } emulator->sector_select_cmd_started = false; } else if(buff_rx_len >= 8) { uint8_t cmd = buff_rx[0]; if(cmd == MF_UL_GET_VERSION_CMD) { if(emulator->data.type >= MfUltralightTypeUL11) { if(buff_rx_len == 1 * 8) { tx_bytes = sizeof(emulator->data.version); memcpy(buff_tx, &emulator->data.version, tx_bytes); *data_type = FURI_HAL_NFC_TXRX_DEFAULT; command_parsed = true; } } } else if(cmd == MF_UL_READ_CMD) { if(buff_rx_len == (1 + 1) * 8) { int16_t start_page = buff_rx[1]; tx_bytes = 16; if(emulator->data.type < MfUltralightTypeNTAGI2C1K) { if(start_page < emulator->page_num) { do { uint8_t copied_pages = 0; uint8_t src_page = start_page; uint8_t last_page_plus_one = start_page + 4; uint8_t pwd_page = emulator->page_num - 2; FuriString* ascii_mirror = NULL; size_t ascii_mirror_len = 0; const char* ascii_mirror_cptr = NULL; uint8_t ascii_mirror_curr_page = 0; uint8_t ascii_mirror_curr_byte = 0; if(last_page_plus_one > emulator->page_num) last_page_plus_one = emulator->page_num; if(emulator->supported_features & MfUltralightSupportAuth) { if(!mf_ul_check_auth(emulator, start_page, false)) break; if(!emulator->auth_success && emulator->config_cache.access.prot && emulator->config_cache.auth0 < last_page_plus_one) last_page_plus_one = emulator->config_cache.auth0; } if(emulator->supported_features & MfUltralightSupportSingleCounter) mf_ul_increment_single_counter(emulator); if(emulator->supported_features & MfUltralightSupportAsciiMirror && emulator->config_cache.mirror.mirror_conf != MfUltralightMirrorNone) { ascii_mirror_curr_byte = emulator->config->mirror.mirror_byte; ascii_mirror_curr_page = emulator->config->mirror_page; // Try to avoid wasting time making mirror if we won't copy it // Conservatively check with UID+counter mirror size if(last_page_plus_one > ascii_mirror_curr_page && start_page + 3 >= ascii_mirror_curr_page && start_page <= ascii_mirror_curr_page + 6) { ascii_mirror = furi_string_alloc(); mf_ul_make_ascii_mirror(emulator, ascii_mirror); ascii_mirror_len = furi_string_utf8_length(ascii_mirror); ascii_mirror_cptr = furi_string_get_cstr(ascii_mirror); // Move pointer to where it should be to start copying if(ascii_mirror_len > 0 && ascii_mirror_curr_page < start_page && ascii_mirror_curr_byte != 0) { uint8_t diff = 4 - ascii_mirror_curr_byte; ascii_mirror_len -= diff; ascii_mirror_cptr += diff; ascii_mirror_curr_byte = 0; ++ascii_mirror_curr_page; } while(ascii_mirror_len > 0 && ascii_mirror_curr_page < start_page) { uint8_t diff = ascii_mirror_len > 4 ? 4 : ascii_mirror_len; ascii_mirror_len -= diff; ascii_mirror_cptr += diff; ++ascii_mirror_curr_page; } } } uint8_t* dest_ptr = buff_tx; while(copied_pages < 4) { // Copy page memcpy(dest_ptr, &emulator->data.data[src_page * 4], 4); // Note: don't have to worry about roll-over with ASCII mirror because // lowest valid page for it is 4, while roll-over will at best read // pages 0-2 if(ascii_mirror_len > 0 && src_page == ascii_mirror_curr_page) { // Copy ASCII mirror size_t copy_len = 4 - ascii_mirror_curr_byte; if(copy_len > ascii_mirror_len) copy_len = ascii_mirror_len; for(size_t i = 0; i < copy_len; ++i) { if(*ascii_mirror_cptr != ' ') dest_ptr[ascii_mirror_curr_byte] = (uint8_t)*ascii_mirror_cptr; ++ascii_mirror_curr_byte; ++ascii_mirror_cptr; } ascii_mirror_len -= copy_len; // Don't care if this is inaccurate after ascii_mirror_len = 0 ascii_mirror_curr_byte = 0; ++ascii_mirror_curr_page; } if(emulator->supported_features & MfUltralightSupportAuth) { if(src_page == pwd_page || src_page == pwd_page + 1) { // Blank out PWD and PACK pages memset(dest_ptr, 0, 4); } } dest_ptr += 4; ++copied_pages; ++src_page; if(src_page >= last_page_plus_one) src_page = 0; } if(ascii_mirror != NULL) { furi_string_free(ascii_mirror); } *data_type = FURI_HAL_NFC_TXRX_DEFAULT; command_parsed = true; } while(false); } } else { uint16_t valid_pages; start_page = mf_ultralight_ntag_i2c_addr_tag_to_lin( &emulator->data, start_page, emulator->curr_sector, &valid_pages); if(start_page != -1) { if(emulator->data.type < MfUltralightTypeNTAGI2CPlus1K || mf_ul_ntag_i2c_plus_check_auth(emulator, buff_rx[1], false)) { if(emulator->data.type >= MfUltralightTypeNTAGI2CPlus1K && emulator->curr_sector == 3 && valid_pages == 1) { // Rewind back a sector to match behavior on a real tag --start_page; ++valid_pages; } uint16_t copy_count = (valid_pages > 4 ? 4 : valid_pages) * 4; FURI_LOG_D( TAG, "NTAG I2C Emu: page valid, %02x:%02x -> %d, %d", emulator->curr_sector, buff_rx[1], start_page, valid_pages); memcpy(buff_tx, &emulator->data.data[start_page * 4], copy_count); // For NTAG I2C, there's no roll-over; remainder is filled by null bytes if(copy_count < tx_bytes) memset(&buff_tx[copy_count], 0, tx_bytes - copy_count); // Special case: NTAG I2C Plus sector 0 page 233 read crosses into page 236 if(start_page == 233) memcpy( &buff_tx[12], &emulator->data.data[(start_page + 1) * 4], 4); mf_ul_protect_auth_data_on_read_command_i2c( buff_tx, start_page, start_page + copy_count / 4 - 1, emulator); *data_type = FURI_HAL_NFC_TXRX_DEFAULT; command_parsed = true; } } else { FURI_LOG_D( TAG, "NTAG I2C Emu: page invalid, %02x:%02x", emulator->curr_sector, buff_rx[1]); if(emulator->data.type >= MfUltralightTypeNTAGI2CPlus1K && emulator->curr_sector == 3 && !emulator->ntag_i2c_plus_sector3_lockout) { // NTAG I2C Plus has a weird behavior where if you read sector 3 // at an invalid address, it responds with zeroes then locks // the read out, while if you read the mirrored session registers, // it returns both session registers on either pages memset(buff_tx, 0, tx_bytes); *data_type = FURI_HAL_NFC_TXRX_DEFAULT; command_parsed = true; emulator->ntag_i2c_plus_sector3_lockout = true; } } } if(!command_parsed) tx_bytes = 0; } } else if(cmd == MF_UL_FAST_READ_CMD) { if(emulator->supported_features & MfUltralightSupportFastRead) { if(buff_rx_len == (1 + 2) * 8) { int16_t start_page = buff_rx[1]; uint8_t end_page = buff_rx[2]; if(start_page <= end_page) { tx_bytes = ((end_page + 1) - start_page) * 4; if(emulator->data.type < MfUltralightTypeNTAGI2C1K) { if((start_page < emulator->page_num) && (end_page < emulator->page_num)) { do { if(emulator->supported_features & MfUltralightSupportAuth) { // NAK if not authenticated and requested pages cross over AUTH0 if(!emulator->auth_success && emulator->config_cache.access.prot && (start_page >= emulator->config_cache.auth0 || end_page >= emulator->config_cache.auth0)) break; } if(emulator->supported_features & MfUltralightSupportSingleCounter) mf_ul_increment_single_counter(emulator); // Copy requested pages memcpy( buff_tx, &emulator->data.data[start_page * 4], tx_bytes); if(emulator->supported_features & MfUltralightSupportAsciiMirror && emulator->config_cache.mirror.mirror_conf != MfUltralightMirrorNone) { // Copy ASCII mirror // Less stringent check here, because expecting FAST_READ to // only be issued once rather than repeatedly FuriString* ascii_mirror; ascii_mirror = furi_string_alloc(); mf_ul_make_ascii_mirror(emulator, ascii_mirror); size_t ascii_mirror_len = furi_string_utf8_length(ascii_mirror); const char* ascii_mirror_cptr = furi_string_get_cstr(ascii_mirror); int16_t mirror_start_offset = (emulator->config->mirror_page - start_page) * 4 + emulator->config->mirror.mirror_byte; if(mirror_start_offset < 0) { if(mirror_start_offset < -(int16_t)ascii_mirror_len) { // Past ASCII mirror, don't copy ascii_mirror_len = 0; } else { ascii_mirror_cptr += -mirror_start_offset; ascii_mirror_len -= -mirror_start_offset; mirror_start_offset = 0; } } if(ascii_mirror_len > 0) { int16_t mirror_end_offset = mirror_start_offset + ascii_mirror_len; if(mirror_end_offset > (end_page + 1) * 4) { mirror_end_offset = (end_page + 1) * 4; ascii_mirror_len = mirror_end_offset - mirror_start_offset; } for(size_t i = 0; i < ascii_mirror_len; ++i) { if(*ascii_mirror_cptr != ' ') buff_tx[mirror_start_offset] = (uint8_t)*ascii_mirror_cptr; ++mirror_start_offset; ++ascii_mirror_cptr; } } furi_string_free(ascii_mirror); } if(emulator->supported_features & MfUltralightSupportAuth) { // Clear PWD and PACK pages uint8_t pwd_page = emulator->page_num - 2; int16_t pwd_page_offset = pwd_page - start_page; // PWD page if(pwd_page_offset >= 0 && pwd_page <= end_page) { memset(&buff_tx[pwd_page_offset * 4], 0, 4); // PACK page if(pwd_page + 1 <= end_page) memset(&buff_tx[(pwd_page_offset + 1) * 4], 0, 4); } } *data_type = FURI_HAL_NFC_TXRX_DEFAULT; command_parsed = true; } while(false); } } else { uint16_t valid_pages; start_page = mf_ultralight_ntag_i2c_addr_tag_to_lin( &emulator->data, start_page, emulator->curr_sector, &valid_pages); if(start_page != -1) { if(emulator->data.type < MfUltralightTypeNTAGI2CPlus1K || mf_ul_ntag_i2c_plus_check_auth(emulator, buff_rx[1], false)) { uint16_t copy_count = tx_bytes; if(copy_count > valid_pages * 4) copy_count = valid_pages * 4; memcpy( buff_tx, &emulator->data.data[start_page * 4], copy_count); if(copy_count < tx_bytes) memset(&buff_tx[copy_count], 0, tx_bytes - copy_count); mf_ul_ntag_i2c_fill_cross_area_read( buff_tx, buff_rx[1], buff_rx[2], emulator); mf_ul_protect_auth_data_on_read_command_i2c( buff_tx, start_page, start_page + copy_count / 4 - 1, emulator); *data_type = FURI_HAL_NFC_TXRX_DEFAULT; command_parsed = true; } } } if(!command_parsed) tx_bytes = 0; } } } } else if(cmd == MF_UL_WRITE) { if(buff_rx_len == (1 + 5) * 8) { do { uint8_t orig_write_page = buff_rx[1]; int16_t write_page = orig_write_page; uint16_t valid_pages; // unused write_page = mf_ultralight_ntag_i2c_addr_tag_to_lin( &emulator->data, write_page, emulator->curr_sector, &valid_pages); if(write_page == -1) // NTAG I2C range check break; else if(write_page < 2 || write_page >= emulator->page_num) // Other MFUL/NTAG range check break; if(emulator->supported_features & MfUltralightSupportAuth) { if(emulator->data.type >= MfUltralightTypeNTAGI2CPlus1K) { if(!mf_ul_ntag_i2c_plus_check_auth(emulator, orig_write_page, true)) break; } else { if(!mf_ul_check_auth(emulator, orig_write_page, true)) break; } } int16_t tag_addr = mf_ultralight_page_addr_to_tag_addr( emulator->curr_sector, orig_write_page); if(!mf_ul_check_lock(emulator, tag_addr)) break; if(emulator->data.type == MfUltralightTypeNTAG203 && orig_write_page == MF_UL_NTAG203_COUNTER_PAGE) { send_ack = mf_ul_emulate_ntag203_counter_write(emulator, &buff_rx[2]); command_parsed = send_ack; } else { mf_ul_emulate_write(emulator, tag_addr, write_page, &buff_rx[2]); send_ack = true; command_parsed = true; } } while(false); } } else if(cmd == MF_UL_FAST_WRITE) { if(emulator->supported_features & MfUltralightSupportFastWrite) { if(buff_rx_len == (1 + 66) * 8) { if(buff_rx[1] == 0xF0 && buff_rx[2] == 0xFF) { // TODO: update when SRAM emulation implemented send_ack = true; command_parsed = true; } } } } else if(cmd == MF_UL_COMP_WRITE) { if(emulator->supported_features & MfUltralightSupportCompatWrite) { if(buff_rx_len == (1 + 1) * 8) { uint8_t write_page = buff_rx[1]; do { if(write_page < 2 || write_page >= emulator->page_num) break; if(emulator->supported_features & MfUltralightSupportAuth && !mf_ul_check_auth(emulator, write_page, true)) break; // Note we don't convert to tag addr here because there's only one sector if(!mf_ul_check_lock(emulator, write_page)) break; emulator->comp_write_cmd_started = true; emulator->comp_write_page_addr = write_page; send_ack = true; command_parsed = true; } while(false); } } } else if(cmd == MF_UL_READ_CNT) { if(emulator->supported_features & MfUltralightSupportReadCounter) { if(buff_rx_len == (1 + 1) * 8) { do { uint8_t cnt_num = buff_rx[1]; // NTAG21x checks if(emulator->supported_features & MfUltralightSupportSingleCounter) { if(cnt_num != 2) break; // Only counter 2 is available if(!emulator->config_cache.access.nfc_cnt_en) break; // NAK if counter not enabled if(emulator->config_cache.access.nfc_cnt_pwd_prot && !emulator->auth_success) break; } if(cnt_num < 3) { buff_tx[0] = emulator->data.counter[cnt_num] & 0xFF; buff_tx[1] = (emulator->data.counter[cnt_num] >> 8) & 0xFF; buff_tx[2] = (emulator->data.counter[cnt_num] >> 16) & 0xFF; tx_bytes = 3; *data_type = FURI_HAL_NFC_TXRX_DEFAULT; command_parsed = true; } } while(false); } } } else if(cmd == MF_UL_INC_CNT) { if(emulator->supported_features & MfUltralightSupportIncrCounter) { if(buff_rx_len == (1 + 5) * 8) { uint8_t cnt_num = buff_rx[1]; uint32_t inc = (buff_rx[2] | (buff_rx[3] << 8) | (buff_rx[4] << 16)); // TODO: can you increment by 0 when counter is at 0xffffff? if((cnt_num < 3) && (emulator->data.counter[cnt_num] != 0x00FFFFFF) && (emulator->data.counter[cnt_num] + inc <= 0x00FFFFFF)) { emulator->data.counter[cnt_num] += inc; // We're RAM-backed, so tearing never happens emulator->data.tearing[cnt_num] = MF_UL_TEARING_FLAG_DEFAULT; emulator->data_changed = true; send_ack = true; command_parsed = true; } } } } else if(cmd == MF_UL_AUTH) { if(emulator->supported_features & MfUltralightSupportAuth) { if(buff_rx_len == (1 + 4) * 8) { uint16_t scaled_authlim = mf_ultralight_calc_auth_count(&emulator->data); if(scaled_authlim != 0 && emulator->data.curr_authlim >= scaled_authlim) { if(emulator->data.curr_authlim != UINT16_MAX) { // Handle case where AUTHLIM has been lowered or changed from 0 emulator->data.curr_authlim = UINT16_MAX; emulator->data_changed = true; } // AUTHLIM reached, always fail buff_tx[0] = MF_UL_NAK_AUTHLIM_REACHED; tx_bits = 4; *data_type = FURI_HAL_NFC_TX_RAW_RX_DEFAULT; mf_ul_reset_emulation(emulator, false); command_parsed = true; } else { if(memcmp(&buff_rx[1], emulator->config->auth_data.pwd.raw, 4) == 0) { // Correct password buff_tx[0] = emulator->config->auth_data.pack.raw[0]; buff_tx[1] = emulator->config->auth_data.pack.raw[1]; tx_bytes = 2; *data_type = FURI_HAL_NFC_TXRX_DEFAULT; emulator->auth_success = true; command_parsed = true; if(emulator->data.curr_authlim != 0) { // Reset current AUTHLIM emulator->data.curr_authlim = 0; emulator->data_changed = true; } } else if(!emulator->config->auth_data.pwd.value) { // Unknown password, pretend to be an Amiibo buff_tx[0] = 0x80; buff_tx[1] = 0x80; tx_bytes = 2; *data_type = FURI_HAL_NFC_TXRX_DEFAULT; emulator->auth_success = true; command_parsed = true; } else { // Wrong password, increase negative verification count if(emulator->data.curr_authlim < UINT16_MAX) { ++emulator->data.curr_authlim; emulator->data_changed = true; } if(scaled_authlim != 0 && emulator->data.curr_authlim >= scaled_authlim) { emulator->data.curr_authlim = UINT16_MAX; buff_tx[0] = MF_UL_NAK_AUTHLIM_REACHED; tx_bits = 4; *data_type = FURI_HAL_NFC_TX_RAW_RX_DEFAULT; mf_ul_reset_emulation(emulator, false); command_parsed = true; } else { // Should delay here to slow brute forcing } } } } } } else if(cmd == MF_UL_READ_SIG) { if(emulator->supported_features & MfUltralightSupportSignature) { // Check 2nd byte = 0x00 - RFU if(buff_rx_len == (1 + 1) * 8 && buff_rx[1] == 0x00) { tx_bytes = sizeof(emulator->data.signature); memcpy(buff_tx, emulator->data.signature, tx_bytes); *data_type = FURI_HAL_NFC_TXRX_DEFAULT; command_parsed = true; } } } else if(cmd == MF_UL_CHECK_TEARING) { if(emulator->supported_features & MfUltralightSupportTearingFlags) { if(buff_rx_len == (1 + 1) * 8) { uint8_t cnt_num = buff_rx[1]; if(cnt_num < 3) { buff_tx[0] = emulator->data.tearing[cnt_num]; tx_bytes = 1; *data_type = FURI_HAL_NFC_TXRX_DEFAULT; command_parsed = true; } } } } else if(cmd == MF_UL_HALT_START) { reset_idle = true; FURI_LOG_D(TAG, "Received HLTA"); } else if(cmd == MF_UL_SECTOR_SELECT) { if(emulator->supported_features & MfUltralightSupportSectorSelect) { if(buff_rx_len == (1 + 1) * 8 && buff_rx[1] == 0xFF) { // Send ACK emulator->sector_select_cmd_started = true; send_ack = true; command_parsed = true; } } } else if(cmd == MF_UL_READ_VCSL) { if(emulator->supported_features & MfUltralightSupportVcsl) { if(buff_rx_len == (1 + 20) * 8) { buff_tx[0] = emulator->config_cache.vctid; tx_bytes = 1; *data_type = FURI_HAL_NFC_TXRX_DEFAULT; command_parsed = true; } } } else { // NTAG203 appears to NAK instead of just falling off on invalid commands if(emulator->data.type != MfUltralightTypeNTAG203) reset_idle = true; FURI_LOG_D(TAG, "Received invalid command"); } } else { reset_idle = true; FURI_LOG_D(TAG, "Received invalid buffer less than 8 bits in length"); } if(reset_idle) { mf_ul_reset_emulation(emulator, false); tx_bits = 0; command_parsed = true; } if(!command_parsed) { // Send NACK buff_tx[0] = MF_UL_NAK_INVALID_ARGUMENT; tx_bits = 4; *data_type = FURI_HAL_NFC_TX_RAW_RX_DEFAULT; // Every NAK should cause reset to IDLE mf_ul_reset_emulation(emulator, false); } else if(send_ack) { buff_tx[0] = MF_UL_ACK; tx_bits = 4; *data_type = FURI_HAL_NFC_TX_RAW_RX_DEFAULT; } if(respond_nothing) { *buff_tx_len = UINT16_MAX; *data_type = FURI_HAL_NFC_TX_RAW_RX_DEFAULT; } else { // Return tx buffer size in bits if(tx_bytes) { tx_bits = tx_bytes * 8; } *buff_tx_len = tx_bits; } #ifdef FURI_DEBUG if(*buff_tx_len == UINT16_MAX) { FURI_LOG_T(TAG, "Emu TX: no reply"); } else if(*buff_tx_len > 0) { int count = (*buff_tx_len + 7) / 8; for(int i = 0; i < count; ++i) { furi_string_cat_printf(debug_buf, "%02x ", buff_tx[i]); } furi_string_trim(debug_buf); FURI_LOG_T(TAG, "Emu TX (%d): %s", *buff_tx_len, furi_string_get_cstr(debug_buf)); furi_string_free(debug_buf); } else { FURI_LOG_T(TAG, "Emu TX: HALT"); } #endif return tx_bits > 0; }