clipper

scenes/metroflip_scene_clipper.c

@@ -0,0 +1,672 @@
+/*
+ * clipper.c - Parser for Clipper cards (San Francisco, California).
+ *
+ * Based on research, some of which dates to 2007!
+ *
+ * Copyright 2024 Jeremy Cooper <jeremy.gthb@baymoo.org>
+ *
+ * This program is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#include <flipper_application.h>
+#include "../metroflip_i.h"
+#include <nfc/protocols/mf_desfire/mf_desfire_poller.h>
+
+#include <lib/nfc/protocols/mf_desfire/mf_desfire.h>
+
+#include <bit_lib.h>
+#include <datetime.h>
+#include <locale/locale.h>
+#include <inttypes.h>
+
+//
+// Table of application ids observed in the wild, and their sources.
+//
+static const struct {
+    const MfDesfireApplicationId app;
+    const char* type;
+} clipper_types[] = {
+    // Application advertised on classic, plastic cards.
+    {.app = {.data = {0x90, 0x11, 0xf2}}, .type = "Card"},
+    // Application advertised on a mobile device.
+    {.app = {.data = {0x91, 0x11, 0xf2}}, .type = "Mobile Device"},
+};
+static const size_t kNumCardTypes = sizeof(clipper_types) / sizeof(clipper_types[0]);
+
+struct IdMapping_struct {
+    uint16_t id;
+    const char* name;
+};
+typedef struct IdMapping_struct IdMapping;
+
+#define COUNT(_array) sizeof(_array) / sizeof(_array[0])
+
+//
+// Known transportation agencies and their identifiers.
+//
+static const IdMapping agency_names[] = {
+    {.id = 0x0001, .name = "AC Transit"},
+    {.id = 0x0004, .name = "BART"},
+    {.id = 0x0006, .name = "Caltrain"},
+    {.id = 0x0008, .name = "CCTA"},
+    {.id = 0x000b, .name = "GGT"},
+    {.id = 0x000f, .name = "SamTrans"},
+    {.id = 0x0011, .name = "VTA"},
+    {.id = 0x0012, .name = "Muni"},
+    {.id = 0x0019, .name = "GG Ferry"},
+    {.id = 0x001b, .name = "SF Bay Ferry"},
+};
+static const size_t kNumAgencies = COUNT(agency_names);
+
+//
+// Known station names for various agencies.
+//
+static const IdMapping bart_zones[] = {
+    {.id = 0x0001, .name = "Colma"},
+    {.id = 0x0002, .name = "Daly City"},
+    {.id = 0x0003, .name = "Balboa Park"},
+    {.id = 0x0004, .name = "Glen Park"},
+    {.id = 0x0005, .name = "24th St Mission"},
+    {.id = 0x0006, .name = "16th St Mission"},
+    {.id = 0x0007, .name = "Civic Center/UN Plaza"},
+    {.id = 0x0008, .name = "Powell St"},
+    {.id = 0x0009, .name = "Montgomery St"},
+    {.id = 0x000a, .name = "Embarcadero"},
+    {.id = 0x000b, .name = "West Oakland"},
+    {.id = 0x000c, .name = "12th St/Oakland City Center"},
+    {.id = 0x000d, .name = "19th St/Oakland"},
+    {.id = 0x000e, .name = "MacArthur"},
+    {.id = 0x000f, .name = "Rockridge"},
+    {.id = 0x0010, .name = "Orinda"},
+    {.id = 0x0011, .name = "Lafayette"},
+    {.id = 0x0012, .name = "Walnut Creek"},
+    {.id = 0x0013, .name = "Pleasant Hill/Contra Costa Centre"},
+    {.id = 0x0014, .name = "Concord"},
+    {.id = 0x0015, .name = "North Concord/Martinez"},
+    {.id = 0x0016, .name = "Pittsburg/Bay Point"},
+    {.id = 0x0017, .name = "Ashby"},
+    {.id = 0x0018, .name = "Downtown Berkeley"},
+    {.id = 0x0019, .name = "North Berkeley"},
+    {.id = 0x001a, .name = "El Cerrito Plaza"},
+    {.id = 0x001b, .name = "El Cerrito Del Norte"},
+    {.id = 0x001c, .name = "Richmond"},
+    {.id = 0x001d, .name = "Lake Merrit"},
+    {.id = 0x001e, .name = "Fruitvale"},
+    {.id = 0x001f, .name = "Coliseum"},
+    {.id = 0x0021, .name = "San Leandro"},
+    {.id = 0x0022, .name = "Hayward"},
+    {.id = 0x0023, .name = "South Hayward"},
+    {.id = 0x0024, .name = "Union City"},
+    {.id = 0x0025, .name = "Fremont"},
+    {.id = 0x0026, .name = "Castro Valley"},
+    {.id = 0x0027, .name = "Dublin/Pleasanton"},
+    {.id = 0x0028, .name = "South San Francisco"},
+    {.id = 0x0029, .name = "San Bruno"},
+    {.id = 0x002a, .name = "SFO Airport"},
+    {.id = 0x002b, .name = "Millbrae"},
+    {.id = 0x002c, .name = "West Dublin/Pleasanton"},
+    {.id = 0x002d, .name = "OAK Airport"},
+    {.id = 0x002e, .name = "Warm Springs/South Fremont"},
+    {.id = 0x002f, .name = "Milpitas"},
+    {.id = 0x0030, .name = "Berryessa/North San Jose"},
+};
+static const size_t kNumBARTZones = COUNT(bart_zones);
+
+static const IdMapping muni_zones[] = {
+    {.id = 0x0000, .name = "City Street"},
+    {.id = 0x0005, .name = "Embarcadero"},
+    {.id = 0x0006, .name = "Montgomery"},
+    {.id = 0x0007, .name = "Powell"},
+    {.id = 0x0008, .name = "Civic Center"},
+    {.id = 0x0009, .name = "Van Ness"}, // Guessed
+    {.id = 0x000a, .name = "Church"},
+    {.id = 0x000b, .name = "Castro"},
+    {.id = 0x000c, .name = "Forest Hill"}, // Guessed
+    {.id = 0x000d, .name = "West Portal"},
+};
+static const size_t kNumMUNIZones = COUNT(muni_zones);
+
+static const IdMapping actransit_zones[] = {
+    {.id = 0x0000, .name = "City Street"},
+};
+static const size_t kNumACTransitZones = COUNT(actransit_zones);
+
+// Instead of persisting individual Station IDs, Caltrain saves Zone numbers.
+// https://www.caltrain.com/stations-zones
+static const IdMapping caltrain_zones[] = {
+    {.id = 0x0001, .name = "Zone 1"},
+    {.id = 0x0002, .name = "Zone 2"},
+    {.id = 0x0003, .name = "Zone 3"},
+    {.id = 0x0004, .name = "Zone 4"},
+    {.id = 0x0005, .name = "Zone 5"},
+    {.id = 0x0006, .name = "Zone 6"},
+};
+
+static const size_t kNumCaltrainZones = COUNT(caltrain_zones);
+
+//
+// Full agency+zone mapping.
+//
+static const struct {
+    uint16_t agency_id;
+    const IdMapping* zone_map;
+    size_t zone_count;
+} agency_zone_map[] = {
+    {.agency_id = 0x0001, .zone_map = actransit_zones, .zone_count = kNumACTransitZones},
+    {.agency_id = 0x0004, .zone_map = bart_zones, .zone_count = kNumBARTZones},
+    {.agency_id = 0x0006, .zone_map = caltrain_zones, .zone_count = kNumCaltrainZones},
+    {.agency_id = 0x0012, .zone_map = muni_zones, .zone_count = kNumMUNIZones}};
+static const size_t kNumAgencyZoneMaps = COUNT(agency_zone_map);
+
+// File ids of important files on the card.
+static const MfDesfireFileId clipper_ecash_file_id = 2;
+static const MfDesfireFileId clipper_histidx_file_id = 6;
+static const MfDesfireFileId clipper_identity_file_id = 8;
+static const MfDesfireFileId clipper_history_file_id = 14;
+
+struct ClipperCardInfo_struct {
+    uint32_t serial_number;
+    uint16_t counter;
+    uint16_t last_txn_id;
+    uint32_t last_updated_tm_1900;
+    uint16_t last_terminal_id;
+    int16_t balance_cents;
+};
+typedef struct ClipperCardInfo_struct ClipperCardInfo;
+
+// Forward declarations for helper functions.
+static void furi_string_cat_timestamp(
+    FuriString* str,
+    const char* date_hdr,
+    const char* time_hdr,
+    uint32_t tmst_1900);
+static bool get_file_contents(
+    const MfDesfireApplication* app,
+    const MfDesfireFileId* id,
+    MfDesfireFileType type,
+    size_t min_size,
+    const uint8_t** out);
+static bool decode_id_file(const uint8_t* ef8_data, ClipperCardInfo* info);
+static bool decode_cash_file(const uint8_t* ef2_data, ClipperCardInfo* info);
+static bool get_map_item(uint16_t id, const IdMapping* map, size_t sz, const char** out);
+static bool get_agency_zone_name(uint16_t agency_id, uint16_t zone_id, const char** out);
+static void
+    decode_usd(int16_t amount_cents, bool* out_is_negative, int16_t* out_usd, uint16_t* out_cents);
+static bool dump_ride_history(
+    const uint8_t* index_file,
+    const uint8_t* history_file,
+    size_t len,
+    FuriString* parsed_data);
+static bool dump_ride_event(const uint8_t* record, FuriString* parsed_data);
+
+// Unmarshal a 32-bit integer, big endian, unsigned
+static inline uint32_t get_u32be(const uint8_t* field) {
+    return bit_lib_bytes_to_num_be(field, 4);
+}
+
+// Unmarshal a 16-bit integer, big endian, unsigned
+static uint16_t get_u16be(const uint8_t* field) {
+    return bit_lib_bytes_to_num_be(field, 2);
+}
+
+// Unmarshal a 16-bit integer, big endian, signed, two's-complement
+static int16_t get_i16be(const uint8_t* field) {
+    uint16_t raw = get_u16be(field);
+    if(raw > 0x7fff)
+        return -((uint32_t)0x10000 - raw);
+    else
+        return raw;
+}
+
+static bool clipper_parse(const NfcDevice* device, FuriString* parsed_data) {
+    furi_assert(device);
+    furi_assert(parsed_data);
+
+    bool parsed = false;
+
+    do {
+        const MfDesfireData* data = nfc_device_get_data(device, NfcProtocolMfDesfire);
+
+        const MfDesfireApplication* app = NULL;
+        const char* device_description = NULL;
+
+        for(size_t i = 0; i < kNumCardTypes; i++) {
+            app = mf_desfire_get_application(data, &clipper_types[i].app);
+            FURI_LOG_I("TAG", "ya");
+            device_description = clipper_types[i].type;
+            if(app != NULL) break;
+        }
+        FURI_LOG_I("TAG", "ya2");
+        // If no matching application was found, abort this parser.
+        if(app == NULL) break;
+        FURI_LOG_I("TAG", "ya3");
+        ClipperCardInfo info;
+        const uint8_t* id_data;
+        if(!get_file_contents(
+               app, &clipper_identity_file_id, MfDesfireFileTypeStandard, 5, &id_data))
+            break;
+        FURI_LOG_I("TAG", "ya4");
+        if(!decode_id_file(id_data, &info)) break;
+        FURI_LOG_I("TAG", "ya5");
+        const uint8_t* cash_data;
+        if(!get_file_contents(app, &clipper_ecash_file_id, MfDesfireFileTypeBackup, 32, &cash_data))
+            break;
+        FURI_LOG_I("TAG", "ya6");
+        if(!decode_cash_file(cash_data, &info)) break;
+        FURI_LOG_I("TAG", "ya7");
+        int16_t balance_usd;
+        uint16_t balance_cents;
+        bool _balance_is_negative;
+        decode_usd(info.balance_cents, &_balance_is_negative, &balance_usd, &balance_cents);
+        FURI_LOG_I("TAG", "ya8");
+        furi_string_cat_printf(
+            parsed_data,
+            "\e#Clipper\n"
+            "Serial: %" PRIu32 "\n"
+            "Balance: $%d.%02u\n"
+            "Type: %s\n"
+            "\e#Last Update\n",
+            info.serial_number,
+            balance_usd,
+            balance_cents,
+            device_description);
+        if(info.last_updated_tm_1900 != 0)
+            furi_string_cat_timestamp(
+                parsed_data, "Date: ", "\nTime: ", info.last_updated_tm_1900);
+        else
+            furi_string_cat_str(parsed_data, "Never");
+        furi_string_cat_printf(
+            parsed_data,
+            "\nTerminal: 0x%04x\n"
+            "Transaction Id: %u\n"
+            "Counter: %u\n",
+            info.last_terminal_id,
+            info.last_txn_id,
+            info.counter);
+
+        const uint8_t *history_index, *history;
+
+        if(!get_file_contents(
+               app, &clipper_histidx_file_id, MfDesfireFileTypeBackup, 16, &history_index))
+            break;
+        if(!get_file_contents(
+               app, &clipper_history_file_id, MfDesfireFileTypeStandard, 512, &history))
+            break;
+
+        if(!dump_ride_history(history_index, history, 512, parsed_data)) break;
+
+        parsed = true;
+    } while(false);
+
+    return parsed;
+}
+
+static bool get_file_contents(
+    const MfDesfireApplication* app,
+    const MfDesfireFileId* id,
+    MfDesfireFileType type,
+    size_t min_size,
+    const uint8_t** out) {
+    const MfDesfireFileSettings* settings = mf_desfire_get_file_settings(app, id);
+    if(settings == NULL) return false;
+    if(settings->type != type) return false;
+
+    const MfDesfireFileData* file_data = mf_desfire_get_file_data(app, id);
+    
+    if(file_data == NULL) return false;
+
+    if(simple_array_get_count(file_data->data) < min_size) return false;
+    
+    *out = simple_array_cget_data(file_data->data);
+
+    return true;
+}
+
+static bool decode_id_file(const uint8_t* ef8_data, ClipperCardInfo* info) {
+    // Identity file (8)
+    //
+    // Byte view
+    //
+    //       0    1    2    3    4    5    6    7    8
+    //       +----+----.----.----.----+----.----.----+
+    // 0x00  | uk | card_id           | unknown      |
+    //       +----+----.----.----.----+----.----.----+
+    // 0x08  | unknown                               |
+    //       +----.----.----.----.----.----.----.----+
+    // 0x10    ...
+    //
+    //
+    // Field          Datatype   Description
+    // -----          --------   -----------
+    // uk             ?8??       Unknown, 8-bit byte
+    // card_id        U32BE      Card identifier
+    //
+    info->serial_number = bit_lib_bytes_to_num_be(&ef8_data[1], 4);
+    return true;
+}
+
+static bool decode_cash_file(const uint8_t* ef2_data, ClipperCardInfo* info) {
+    // ECash file (2)
+    //
+    // Byte view
+    //
+    //       0    1    2    3    4    5    6    7    8
+    //       +----.----+----.----+----.----.----.----+
+    // 0x00  |  unk00  | counter | timestamp_1900    |
+    //       +----.----+----.----+----.----.----.----+
+    // 0x08  | term_id |     unk01                   |
+    //       +----.----+----.----+----.----.----.----+
+    // 0x10  | txn_id  | balance |      unknown      |
+    //       +----.----+----.----+----.----.----.----+
+    // 0x18  |               unknown                 |
+    //       +---------------------------------------+
+    //
+    // Field          Datatype Description
+    // -----          -------- -----------
+    // unk00          U8[2]     Unknown bytes
+    // counter        U16BE     Unknown, appears to be a counter
+    // timestamp_1900 U32BE     Timestamp of last transaction, in seconds
+    //                          since 1900-01-01 GMT.
+    // unk01          U8[6]     Unknown bytes
+    // txn_id         U16BE     Id of last transaction.
+    // balance        S16BE     Card cash balance, in cents.
+    //                          Cards can obtain negative balances in this
+    //                          system, so balances are signed integers.
+    //                          Maximum card balance is therefore
+    //                          $327.67.
+    // unk02          U8[12]    Unknown bytes.
+    //
+    info->counter = get_u16be(&ef2_data[2]);
+    info->last_updated_tm_1900 = get_u32be(&ef2_data[4]);
+    info->last_terminal_id = get_u16be(&ef2_data[8]);
+    info->last_txn_id = get_u16be(&ef2_data[0x10]);
+    info->balance_cents = get_i16be(&ef2_data[0x12]);
+    return true;
+}
+
+static bool dump_ride_history(
+    const uint8_t* index_file,
+    const uint8_t* history_file,
+    size_t len,
+    FuriString* parsed_data) {
+    static const size_t kRideRecordSize = 0x20;
+
+    for(size_t i = 0; i < 16; i++) {
+        uint8_t record_num = index_file[i];
+        if(record_num == 0xff) break;
+
+        size_t record_offset = record_num * kRideRecordSize;
+
+        if(record_offset + kRideRecordSize > len) break;
+
+        const uint8_t* record = &history_file[record_offset];
+        if(!dump_ride_event(record, parsed_data)) break;
+    }
+
+    return true;
+}
+
+static bool dump_ride_event(const uint8_t* record, FuriString* parsed_data) {
+    // Ride record
+    //
+    //       0    1    2    3    4    5    6    7    8
+    //       +----+----+----.----+----.----+----.----+
+    // 0x00  |0x10| ?  | agency  | ?       | fare    |
+    //       +----.----+----.----+----.----.----.----+
+    // 0x08  | ?       | vehicle | time_on           |
+    //       +----.----.----.----+----.----+----.----+
+    // 0x10  | time_off          | zone_on | zone_off|
+    //       +----+----.----.----.----+----+----+----+
+    // 0x18  | ?  | ?                 | ?  | ?  | ?  |
+    //       +----+----.----.----.----+----+----+----+
+    //
+    // Field          Datatype Description
+    // -----          -------- -----------
+    // agency         U16BE    Transportation agency identifier.
+    //                         Known ids:
+    //                         1  == AC Transit
+    //                         4  == BART
+    //                         18 == SF MUNI
+    // fare           I16BE    Fare deducted, in cents.
+    // vehicle        U16BE    Vehicle id (0 == not provided)
+    // time_on        U32BE    Boarding time, in seconds since 1900-01-01 GMT.
+    // time_off       U32BE    Off-boarding time, if present, in seconds
+    //                         since 1900-01-01 GMT. Set to zero if no offboard
+    //                         has been recorded.
+    // zone_on        U16BE    Id of boarding zone or station. Agency-specific.
+    // zone_off       U16BE    Id of offboarding zone or station. Agency-
+    //                         specific.
+    if(record[0] != 0x10) return false;
+
+    uint16_t agency_id = get_u16be(&record[2]);
+    if(agency_id == 0)
+        // Likely empty record. Skip.
+        return false;
+    const char* agency_name;
+    bool ok = get_map_item(agency_id, agency_names, kNumAgencies, &agency_name);
+    if(!ok) agency_name = "Unknown";
+
+    uint16_t vehicle_id = get_u16be(&record[0x0a]);
+
+    int16_t fare_raw_cents = get_i16be(&record[6]);
+    bool _fare_is_negative;
+    int16_t fare_usd;
+    uint16_t fare_cents;
+    decode_usd(fare_raw_cents, &_fare_is_negative, &fare_usd, &fare_cents);
+
+    uint32_t time_on_raw = get_u32be(&record[0x0c]);
+    uint32_t time_off_raw = get_u32be(&record[0x10]);
+    uint16_t zone_id_on = get_u16be(&record[0x14]);
+    uint16_t zone_id_off = get_u16be(&record[0x16]);
+
+    const char *zone_on, *zone_off;
+    if(!get_agency_zone_name(agency_id, zone_id_on, &zone_on)) {
+        zone_on = "Unknown";
+    }
+    if(!get_agency_zone_name(agency_id, zone_id_off, &zone_off)) {
+        zone_off = "Unknown";
+    }
+
+    furi_string_cat_str(parsed_data, "\e#Ride Record\n");
+    furi_string_cat_timestamp(parsed_data, "Date: ", "\nTime: ", time_on_raw);
+    furi_string_cat_printf(
+        parsed_data,
+        "\n"
+        "Fare: $%d.%02u\n"
+        "Agency: %s (%04x)\n"
+        "On: %s (%04x)\n",
+        fare_usd,
+        fare_cents,
+        agency_name,
+        agency_id,
+        zone_on,
+        zone_id_on);
+    if(vehicle_id != 0) {
+        furi_string_cat_printf(parsed_data, "Vehicle id: %d\n", vehicle_id);
+    }
+    if(time_off_raw != 0) {
+        furi_string_cat_printf(parsed_data, "Off: %s (%04x)\n", zone_off, zone_id_off);
+        furi_string_cat_timestamp(parsed_data, "Date Off: ", "\nTime Off: ", time_off_raw);
+        furi_string_cat_str(parsed_data, "\n");
+    }
+
+    return true;
+}
+
+static bool get_map_item(uint16_t id, const IdMapping* map, size_t sz, const char** out) {
+    for(size_t i = 0; i < sz; i++) {
+        if(map[i].id == id) {
+            *out = map[i].name;
+            return true;
+        }
+    }
+
+    return false;
+}
+
+static bool get_agency_zone_name(uint16_t agency_id, uint16_t zone_id, const char** out) {
+    for(size_t i = 0; i < kNumAgencyZoneMaps; i++) {
+        if(agency_zone_map[i].agency_id == agency_id) {
+            return get_map_item(
+                zone_id, agency_zone_map[i].zone_map, agency_zone_map[i].zone_count, out);
+        }
+    }
+
+    return false;
+}
+
+// Split a balance/fare amount from raw cents to dollars and cents portion,
+// automatically adjusting the cents portion so that it is always positive,
+// for easier display.
+static void
+    decode_usd(int16_t amount_cents, bool* out_is_negative, int16_t* out_usd, uint16_t* out_cents) {
+    *out_usd = amount_cents / 100;
+
+    if(amount_cents >= 0) {
+        *out_is_negative = false;
+        *out_cents = amount_cents % 100;
+    } else {
+        *out_is_negative = true;
+        *out_cents = (amount_cents * -1) % 100;
+    }
+}
+
+void metroflip_clipper_widget_callback(GuiButtonType result, InputType type, void* context) {
+    Metroflip* app = context;
+    UNUSED(result);
+
+    if(type == InputTypeShort) {
+        scene_manager_search_and_switch_to_previous_scene(app->scene_manager, MetroflipSceneStart);
+    }
+}
+
+
+// Decode a raw 1900-based timestamp and append a human-readable form to a
+// FuriString.
+static void furi_string_cat_timestamp(
+    FuriString* str,
+    const char* date_hdr,
+    const char* time_hdr,
+    uint32_t tmst_1900) {
+    DateTime tm;
+
+    datetime_timestamp_to_datetime(tmst_1900, &tm);
+
+    FuriString* date_str = furi_string_alloc();
+    locale_format_date(date_str, &tm, locale_get_date_format(), "-");
+
+    FuriString* time_str = furi_string_alloc();
+    locale_format_time(time_str, &tm, locale_get_time_format(), true);
+
+    furi_string_cat_printf(
+        str,
+        "%s%s%s%s (UTC)",
+        date_hdr,
+        furi_string_get_cstr(date_str),
+        time_hdr,
+        furi_string_get_cstr(time_str));
+
+    furi_string_free(date_str);
+    furi_string_free(time_str);
+}
+
+static NfcCommand metroflip_scene_clipper_poller_callback(NfcGenericEvent event, void* context) {
+    furi_assert(event.protocol == NfcProtocolMfDesfire);
+
+    Metroflip* app = context;
+    NfcCommand command = NfcCommandContinue;
+
+    FuriString* parsed_data = furi_string_alloc();
+    Widget* widget = app->widget;
+    furi_string_reset(app->text_box_store);
+    const MfDesfirePollerEvent* mf_desfire_event = event.event_data;
+    if(mf_desfire_event->type == MfDesfirePollerEventTypeReadSuccess) {
+        nfc_device_set_data(
+            app->nfc_device, NfcProtocolMfDesfire, nfc_poller_get_data(app->poller));
+        clipper_parse(app->nfc_device, parsed_data);
+        widget_add_text_scroll_element(
+            widget, 0, 0, 128, 64, furi_string_get_cstr(parsed_data));
+
+        widget_add_button_element(
+            widget, GuiButtonTypeRight, "Exit", metroflip_clipper_widget_callback, app);
+
+        furi_string_free(parsed_data);
+        view_dispatcher_switch_to_view(app->view_dispatcher, MetroflipViewWidget);
+        metroflip_app_blink_stop(app);
+        command = NfcCommandStop;
+    } else if(mf_desfire_event->type == MfDesfirePollerEventTypeReadFailed) {
+        view_dispatcher_send_custom_event(app->view_dispatcher, MetroflipCustomEventPollerSuccess);
+        command = NfcCommandReset;
+    }
+
+    return command;
+}
+
+void metroflip_scene_clipper_on_enter(void* context) {
+    Metroflip* app = context;
+    dolphin_deed(DolphinDeedNfcRead);
+
+    // Setup view
+    Popup* popup = app->popup;
+    popup_set_header(popup, "Apply\n card to\nthe back", 68, 30, AlignLeft, AlignTop);
+    popup_set_icon(popup, 0, 3, &I_RFIDDolphinReceive_97x61);
+
+    // Start worker
+    view_dispatcher_switch_to_view(app->view_dispatcher, MetroflipViewPopup);
+    nfc_scanner_alloc(app->nfc);
+    app->poller = nfc_poller_alloc(app->nfc, NfcProtocolMfDesfire);
+    nfc_poller_start(app->poller, metroflip_scene_clipper_poller_callback, app);
+
+    metroflip_app_blink_start(app);
+}
+
+bool metroflip_scene_clipper_on_event(void* context, SceneManagerEvent event) {
+    Metroflip* app = context;
+    bool consumed = false;
+
+    if(event.type == SceneManagerEventTypeCustom) {
+        if(event.event == MetroflipCustomEventCardDetected) {
+            Popup* popup = app->popup;
+            popup_set_header(popup, "DON'T\nMOVE", 68, 30, AlignLeft, AlignTop);
+            consumed = true;
+        } else if(event.event == MetroflipCustomEventCardLost) {
+            Popup* popup = app->popup;
+            popup_set_header(popup, "Card \n lost", 68, 30, AlignLeft, AlignTop);
+            consumed = true;
+        } else if(event.event == MetroflipCustomEventWrongCard) {
+            Popup* popup = app->popup;
+            popup_set_header(popup, "WRONG \n CARD", 68, 30, AlignLeft, AlignTop);
+            consumed = true;
+        } else if(event.event == MetroflipCustomEventPollerFail) {
+            Popup* popup = app->popup;
+            popup_set_header(popup, "Failed", 68, 30, AlignLeft, AlignTop);
+            consumed = true;
+        } 
+    } else if(event.type == SceneManagerEventTypeBack) {
+        scene_manager_search_and_switch_to_previous_scene(app->scene_manager, MetroflipSceneStart);
+        consumed = true;
+    }
+
+    return consumed;
+}
+
+void metroflip_scene_clipper_on_exit(void* context) {
+    Metroflip* app = context;
+    widget_reset(app->widget);
+    metroflip_app_blink_stop(app);
+
+    if(app->poller) {
+        nfc_poller_stop(app->poller);
+        nfc_poller_free(app->poller);
+    }
+}

scenes/metroflip_scene_config.h

@@ -2,6 +2,7 @@ ADD_SCENE(metroflip, start, Start)
 ADD_SCENE(metroflip, ravkav, RavKav)
 ADD_SCENE(metroflip, navigo, Navigo)
 ADD_SCENE(metroflip, charliecard, CharlieCard)
+ADD_SCENE(metroflip, clipper, Clipper)
 ADD_SCENE(metroflip, metromoney, Metromoney)
 ADD_SCENE(metroflip, read_success, ReadSuccess)
 ADD_SCENE(metroflip, bip, Bip)

scenes/metroflip_scene_start.c

@@ -24,6 +24,13 @@ void metroflip_scene_start_on_enter(void* context) {
         metroflip_scene_start_submenu_callback,
         app);
 
+    submenu_add_item(
+        submenu,
+        "Clipper",
+        MetroflipSceneClipper,
+        metroflip_scene_start_submenu_callback,
+        app);
+
     submenu_add_item(
         submenu,
         "Metromoney",