unleashed-firmware/lib/nfc/protocols/felica/felica_poller.c

#include "felica_poller_i.h"
#include <mlib/m-array.h>
#include <mlib/m-core.h>

#include <nfc/protocols/nfc_poller_base.h>

#include <furi.h>
#include <furi_hal.h>

#define TAG "FelicaPoller"

ARRAY_DEF(felica_service_array, FelicaService, M_POD_OPLIST); // -V658
ARRAY_DEF(felica_area_array, FelicaArea, M_POD_OPLIST); // -V658
ARRAY_DEF(felica_public_block_array, FelicaPublicBlock, M_POD_OPLIST); // -V658

typedef NfcCommand (*FelicaPollerReadHandler)(FelicaPoller* instance);

const FelicaData* felica_poller_get_data(FelicaPoller* instance) {
    furi_assert(instance);
    furi_assert(instance->data);

    return instance->data;
}

static FelicaPoller* felica_poller_alloc(Nfc* nfc) {
    furi_assert(nfc);

    FelicaPoller* instance = malloc(sizeof(FelicaPoller));
    instance->nfc = nfc;
    instance->tx_buffer = bit_buffer_alloc(FELICA_POLLER_MAX_BUFFER_SIZE);
    instance->rx_buffer = bit_buffer_alloc(FELICA_POLLER_MAX_BUFFER_SIZE);

    nfc_config(instance->nfc, NfcModePoller, NfcTechFelica);
    nfc_set_guard_time_us(instance->nfc, FELICA_GUARD_TIME_US);
    nfc_set_fdt_poll_fc(instance->nfc, FELICA_FDT_POLL_FC);
    nfc_set_fdt_poll_poll_us(instance->nfc, FELICA_POLL_POLL_MIN_US);

    mbedtls_des3_init(&instance->auth.des_context);
    instance->data = felica_alloc();

    instance->felica_event.data = &instance->felica_event_data;
    instance->general_event.protocol = NfcProtocolFelica;
    instance->general_event.event_data = &instance->felica_event;
    instance->general_event.instance = instance;

    return instance;
}

static void felica_poller_free(FelicaPoller* instance) {
    furi_assert(instance);

    furi_assert(instance->tx_buffer);
    furi_assert(instance->rx_buffer);
    furi_assert(instance->data);

    mbedtls_des3_free(&instance->auth.des_context);
    bit_buffer_free(instance->tx_buffer);
    bit_buffer_free(instance->rx_buffer);
    felica_free(instance->data);
    free(instance);
}

static void
    felica_poller_set_callback(FelicaPoller* instance, NfcGenericCallback callback, void* context) {
    furi_assert(instance);
    furi_assert(callback);

    instance->callback = callback;
    instance->context = context;
}

NfcCommand felica_poller_state_handler_idle(FelicaPoller* instance) {
    FURI_LOG_D(TAG, "Idle");
    felica_reset(instance->data);
    instance->state = FelicaPollerStateActivated;

    return NfcCommandContinue;
}

NfcCommand felica_poller_state_handler_activate(FelicaPoller* instance) {
    FURI_LOG_D(TAG, "Activate");

    NfcCommand command = NfcCommandContinue;

    FelicaError error = felica_poller_activate(instance, instance->data);
    if(error == FelicaErrorNone) {
        furi_hal_random_fill_buf(instance->data->data.fs.rc.data, FELICA_DATA_BLOCK_SIZE);
        felica_get_workflow_type(instance->data);

        instance->felica_event.type = FelicaPollerEventTypeRequestAuthContext;
        instance->felica_event_data.auth_context = &instance->auth.context;

        instance->callback(instance->general_event, instance->context);

        switch(instance->data->workflow_type) {
        case FelicaStandard:
            instance->state = FelicaPollerStateTraverseStandardSystem;
            break;
        case FelicaLite:
            instance->state = FelicaPollerStateReadLiteBlocks;
            break;
        default:
            // Unimplemented
            instance->state = FelicaPollerStateReadSuccess;
            break;
        }

        bool skip_auth = instance->auth.context.skip_auth;
        if(!skip_auth) {
            instance->state = FelicaPollerStateAuthenticateInternal;
        }
    } else if(error != FelicaErrorTimeout) {
        instance->felica_event.type = FelicaPollerEventTypeError;
        instance->felica_event_data.error = error;
        instance->state = FelicaPollerStateReadFailed;
    }
    return command;
}

NfcCommand felica_poller_state_handler_auth_internal(FelicaPoller* instance) {
    FURI_LOG_D(TAG, "Auth Internal");

    felica_calculate_session_key(
        &instance->auth.des_context,
        instance->auth.context.card_key.data,
        instance->data->data.fs.rc.data,
        instance->auth.session_key.data);

    switch(instance->data->workflow_type) {
    case FelicaStandard:
        instance->state = FelicaPollerStateTraverseStandardSystem;
        break;
    case FelicaLite:
        instance->state = FelicaPollerStateReadLiteBlocks;
        break;
    default:
        // Unimplemented
        instance->state = FelicaPollerStateReadSuccess;
        break;
    }

    uint8_t blocks[3] = {FELICA_BLOCK_INDEX_RC, 0, 0};
    FelicaPollerWriteCommandResponse* tx_resp;
    do {
        FelicaError error = felica_poller_write_blocks(
            instance, 1, blocks, instance->data->data.fs.rc.data, &tx_resp);
        if((error != FelicaErrorNone) || (tx_resp->SF1 != 0) || (tx_resp->SF2 != 0)) break;

        blocks[0] = FELICA_BLOCK_INDEX_ID;
        blocks[1] = FELICA_BLOCK_INDEX_WCNT;
        blocks[2] = FELICA_BLOCK_INDEX_MAC_A;
        FelicaPollerReadCommandResponse* rx_resp;
        error = felica_poller_read_blocks(
            instance, sizeof(blocks), blocks, FELICA_SERVICE_RO_ACCESS, &rx_resp);
        if(error != FelicaErrorNone || rx_resp->SF1 != 0 || rx_resp->SF2 != 0) break;

        if(felica_check_mac(
               &instance->auth.des_context,
               instance->auth.session_key.data,
               instance->data->data.fs.rc.data,
               blocks,
               rx_resp->block_count,
               rx_resp->data)) {
            instance->auth.context.auth_status.internal = true;
            instance->data->data.fs.wcnt.SF1 = 0;
            instance->data->data.fs.wcnt.SF2 = 0;
            memcpy(
                instance->data->data.fs.wcnt.data,
                rx_resp->data + FELICA_DATA_BLOCK_SIZE,
                FELICA_DATA_BLOCK_SIZE);
            instance->state = FelicaPollerStateAuthenticateExternal;
        }
    } while(false);

    return NfcCommandContinue;
}

NfcCommand felica_poller_state_handler_auth_external(FelicaPoller* instance) {
    FURI_LOG_D(TAG, "Auth External");
    uint8_t blocks[2];

    instance->data->data.fs.state.data[0] = 1;
    FelicaAuthentication* auth = &instance->auth;
    felica_calculate_mac_write(
        &auth->des_context,
        auth->session_key.data,
        instance->data->data.fs.rc.data,
        instance->data->data.fs.wcnt.data,
        instance->data->data.fs.state.data,
        instance->data->data.fs.mac_a.data);

    memcpy(instance->data->data.fs.mac_a.data + 8, instance->data->data.fs.wcnt.data, 3); //-V1086

    uint8_t tx_data[FELICA_DATA_BLOCK_SIZE * 2];
    memcpy(tx_data, instance->data->data.fs.state.data, FELICA_DATA_BLOCK_SIZE);
    memcpy(
        tx_data + FELICA_DATA_BLOCK_SIZE,
        instance->data->data.fs.mac_a.data,
        FELICA_DATA_BLOCK_SIZE);

    do {
        blocks[0] = FELICA_BLOCK_INDEX_STATE;
        blocks[1] = FELICA_BLOCK_INDEX_MAC_A;
        FelicaPollerWriteCommandResponse* tx_resp;
        FelicaError error = felica_poller_write_blocks(instance, 2, blocks, tx_data, &tx_resp);
        if(error != FelicaErrorNone || tx_resp->SF1 != 0 || tx_resp->SF2 != 0) break;

        FelicaPollerReadCommandResponse* rx_resp;
        error = felica_poller_read_blocks(instance, 1, blocks, FELICA_SERVICE_RO_ACCESS, &rx_resp);
        if(error != FelicaErrorNone || rx_resp->SF1 != 0 || rx_resp->SF2 != 0) break;

        instance->data->data.fs.state.SF1 = 0;
        instance->data->data.fs.state.SF2 = 0;
        memcpy(instance->data->data.fs.state.data, rx_resp->data, FELICA_DATA_BLOCK_SIZE);
        instance->auth.context.auth_status.external = instance->data->data.fs.state.data[0];
    } while(false);

    switch(instance->data->workflow_type) {
    case FelicaStandard:
        instance->state = FelicaPollerStateTraverseStandardSystem;
        break;
    case FelicaLite:
        instance->state = FelicaPollerStateReadLiteBlocks;
        break;
    default:
        // Unimplemented
        instance->state = FelicaPollerStateReadSuccess;
        break;
    }

    return NfcCommandContinue;
}

NfcCommand felica_poller_state_handler_traverse_standard_system(FelicaPoller* instance) {
    FURI_LOG_D(TAG, "Traverse Standard System");

    FelicaListServiceCommandResponse* response;

    felica_service_array_t service_buffer;
    felica_service_array_init(service_buffer);
    felica_area_array_t area_buffer;
    felica_area_array_init(area_buffer);

    for(uint16_t cursor = 0; cursor < 0xFFFF; cursor++) {
        FelicaError error = felica_poller_list_service_by_cursor(instance, cursor, &response);
        if(error != FelicaErrorNone) {
            FURI_LOG_E(TAG, "Error %d at cursor %04X", error, cursor);
            break;
        }

        uint8_t len = response->header.length;
        const uint8_t* list_service_payload = response->data;
        uint16_t code_begin = (uint16_t)(list_service_payload[0] | (list_service_payload[1] << 8));

        if(len != 0x0C && len != 0x0E) {
            FURI_LOG_E(TAG, "Bad command resp length 0x%02X at cursor 0x%04X", len, cursor);
            break;
        }

        if(code_begin == 0xFFFF) {
            FURI_LOG_D(TAG, "Traverse complete");
            break;
        }

        if(len == 0x0E) {
            FelicaArea* area = felica_area_array_push_raw(area_buffer);
            memset(area, 0, sizeof *area);
            area->code = code_begin;
            area->first_idx = (uint16_t)felica_service_array_size(service_buffer);
            area->last_idx = 0;
        } else {
            FelicaService* service = felica_service_array_push_raw(service_buffer);
            memset(service, 0, sizeof *service);
            service->code = code_begin;
            service->attr = (uint8_t)(code_begin & 0x3F);

            if(felica_area_array_size(area_buffer)) {
                FelicaArea* current_area = felica_area_array_back(area_buffer);
                current_area->last_idx = (uint16_t)(felica_service_array_size(service_buffer) - 1);
            }
        }
    }

    const size_t service_num = felica_service_array_size(service_buffer);
    const size_t area_num = felica_area_array_size(area_buffer);

    if(service_num) {
        simple_array_init(instance->data->services, (uint32_t)service_num);
        memcpy(
            simple_array_get(instance->data->services, 0),
            service_buffer->ptr,
            service_num * sizeof(FelicaService));
    } else {
        simple_array_reset(instance->data->services);
    }

    if(area_num) {
        simple_array_init(instance->data->areas, (uint32_t)area_num);
        memcpy(
            simple_array_get(instance->data->areas, 0),
            area_buffer->ptr,
            area_num * sizeof(FelicaArea));
    } else {
        simple_array_reset(instance->data->areas);
    }

    FURI_LOG_I(
        TAG,
        "Services found: %lu, Areas found: %lu",
        simple_array_get_count(instance->data->services),
        simple_array_get_count(instance->data->areas));

    felica_service_array_clear(service_buffer);
    felica_area_array_clear(area_buffer);

    instance->state = FelicaPollerStateReadStandardBlocks;
    return NfcCommandContinue;
}

NfcCommand felica_poller_state_handler_read_standard_blocks(FelicaPoller* instance) {
    FURI_LOG_D(TAG, "Read Standard Blocks");

    const uint32_t service_count = simple_array_get_count(instance->data->services);

    felica_public_block_array_t public_block_buffer;
    felica_public_block_array_init(public_block_buffer);

    instance->state = FelicaPollerStateReadSuccess;
    bool have_read_anything = false;

    for(uint32_t i = 0; i < service_count; i++) {
        const FelicaService* service = simple_array_get(instance->data->services, i);

        if((service->attr & FELICA_SERVICE_ATTRIBUTE_UNAUTH_READ) == 0) continue;

        uint8_t block_count = 1;
        uint8_t block_list[1] = {0};
        FelicaError error = FelicaErrorNone;
        FelicaPollerReadCommandResponse* response;
        do {
            error = felica_poller_read_blocks(
                instance, block_count, block_list, service->code, &response);

            if(error != FelicaErrorNone) {
                break;
            }

            if(response->SF1 == 0 && response->SF2 == 0) {
                FelicaPublicBlock* public_block =
                    felica_public_block_array_push_raw(public_block_buffer);
                memset(public_block, 0, sizeof *public_block);
                memcpy(public_block->block.data, response->data, FELICA_DATA_BLOCK_SIZE);

                public_block->service_code = service->code;
                public_block->block_idx = block_list[0];

                have_read_anything = true;
                block_list[0]++;
            } else {
                break; // No more blocks to read in this service, ok to continue for loop
            }
        } while(block_list[0] < FELICA_STANDARD_MAX_BLOCK_COUNT);

        if(error != FelicaErrorNone) {
            instance->felica_event.type = FelicaPollerEventTypeError;
            instance->felica_event_data.error = error;
            instance->state = FelicaPollerStateReadFailed;
            break;
        }
    }

    if(have_read_anything) {
        const size_t n = felica_public_block_array_size(public_block_buffer);
        simple_array_init(instance->data->public_blocks, (uint32_t)n);
        memcpy(
            simple_array_get(instance->data->public_blocks, 0),
            public_block_buffer->ptr,
            n * sizeof(FelicaPublicBlock));
    }

    felica_public_block_array_clear(public_block_buffer);

    return NfcCommandContinue;
}

NfcCommand felica_poller_state_handler_read_lite_blocks(FelicaPoller* instance) {
    FURI_LOG_D(TAG, "Read Lite Blocks");

    uint8_t block_count = 1;
    uint8_t block_list[4] = {0, 0, 0, 0};
    block_list[0] = instance->block_index;

    instance->block_index++;
    if(instance->block_index == FELICA_BLOCK_INDEX_REG + 1) {
        instance->block_index = FELICA_BLOCK_INDEX_RC;
    } else if(instance->block_index == FELICA_BLOCK_INDEX_MC + 1) {
        instance->block_index = FELICA_BLOCK_INDEX_WCNT;
    } else if(instance->block_index == FELICA_BLOCK_INDEX_STATE + 1) {
        instance->block_index = FELICA_BLOCK_INDEX_CRC_CHECK;
    }

    FelicaPollerReadCommandResponse* response;
    FelicaError error = felica_poller_read_blocks(
        instance, block_count, block_list, FELICA_SERVICE_RO_ACCESS, &response);
    if(error == FelicaErrorNone) {
        block_count = (response->SF1 == 0) ? response->block_count : block_count;
        uint8_t* data_ptr =
            instance->data->data.dump + instance->data->blocks_total * sizeof(FelicaBlock);

        *data_ptr++ = response->SF1;
        *data_ptr++ = response->SF2;

        if(response->SF1 == 0) {
            uint8_t* response_data_ptr = response->data;
            instance->data->blocks_read++;
            memcpy(data_ptr, response_data_ptr, FELICA_DATA_BLOCK_SIZE);
        } else {
            memset(data_ptr, 0, FELICA_DATA_BLOCK_SIZE);
        }
        instance->data->blocks_total++;

        if(instance->data->blocks_total == FELICA_BLOCKS_TOTAL_COUNT) {
            instance->state = FelicaPollerStateReadSuccess;
        }
    } else {
        instance->felica_event.type = FelicaPollerEventTypeError;
        instance->felica_event_data.error = error;
        instance->state = FelicaPollerStateReadFailed;
    }

    return NfcCommandContinue;
}

NfcCommand felica_poller_state_handler_read_success(FelicaPoller* instance) {
    FURI_LOG_D(TAG, "Read Success");

    if(!instance->auth.context.auth_status.internal ||
       !instance->auth.context.auth_status.external) {
        instance->data->blocks_read--;
        instance->felica_event.type = FelicaPollerEventTypeIncomplete;
    } else {
        memcpy(
            instance->data->data.fs.ck.data,
            instance->auth.context.card_key.data,
            FELICA_DATA_BLOCK_SIZE);
        instance->felica_event.type = FelicaPollerEventTypeReady;
    }

    instance->felica_event_data.error = FelicaErrorNone;
    return instance->callback(instance->general_event, instance->context);
}

NfcCommand felica_poller_state_handler_read_failed(FelicaPoller* instance) {
    FURI_LOG_D(TAG, "Read Fail");
    instance->callback(instance->general_event, instance->context);

    return NfcCommandStop;
}

static const FelicaPollerReadHandler felica_poller_handler[FelicaPollerStateNum] = {
    [FelicaPollerStateIdle] = felica_poller_state_handler_idle,
    [FelicaPollerStateActivated] = felica_poller_state_handler_activate,
    [FelicaPollerStateAuthenticateInternal] = felica_poller_state_handler_auth_internal,
    [FelicaPollerStateAuthenticateExternal] = felica_poller_state_handler_auth_external,
    [FelicaPollerStateTraverseStandardSystem] =
        felica_poller_state_handler_traverse_standard_system,
    [FelicaPollerStateReadStandardBlocks] = felica_poller_state_handler_read_standard_blocks,
    [FelicaPollerStateReadLiteBlocks] = felica_poller_state_handler_read_lite_blocks,
    [FelicaPollerStateReadSuccess] = felica_poller_state_handler_read_success,
    [FelicaPollerStateReadFailed] = felica_poller_state_handler_read_failed,
};

static NfcCommand felica_poller_run(NfcGenericEvent event, void* context) {
    furi_assert(context);
    furi_assert(event.protocol == NfcProtocolInvalid);
    furi_assert(event.event_data);

    FelicaPoller* instance = context;
    NfcEvent* nfc_event = event.event_data;
    NfcCommand command = NfcCommandContinue;

    if(nfc_event->type == NfcEventTypePollerReady) {
        command = felica_poller_handler[instance->state](instance);
    }

    return command;
}

static bool felica_poller_detect(NfcGenericEvent event, void* context) {
    furi_assert(context);
    furi_assert(event.event_data);
    furi_assert(event.instance);
    furi_assert(event.protocol == NfcProtocolInvalid);

    bool protocol_detected = false;
    FelicaPoller* instance = context;
    NfcEvent* nfc_event = event.event_data;
    furi_assert(instance->state == FelicaPollerStateIdle);

    if(nfc_event->type == NfcEventTypePollerReady) {
        FelicaError error = felica_poller_activate(instance, instance->data);
        protocol_detected = (error == FelicaErrorNone);
    }

    return protocol_detected;
}

const NfcPollerBase nfc_poller_felica = {
    .alloc = (NfcPollerAlloc)felica_poller_alloc,
    .free = (NfcPollerFree)felica_poller_free,
    .set_callback = (NfcPollerSetCallback)felica_poller_set_callback,
    .run = (NfcPollerRun)felica_poller_run,
    .detect = (NfcPollerDetect)felica_poller_detect,
    .get_data = (NfcPollerGetData)felica_poller_get_data,
};