Implement support for reading Opal card (Sydney, Australia) (#2683)

* Implement support for reading Opal card (Sydney, Australia)
* stub_parser_verify_read: used UNUSED macro
* furi_hal_rtc: expose calendaring as functions
* opal: use bit-packed struct to parse, rather than manually shifting about
* Update f18 api symbols

Co-authored-by: あく <alleteam@gmail.com>

applications/main/nfc/scenes/nfc_scene_device_info.c

@@ -52,6 +52,7 @@ void nfc_scene_device_info_on_enter(void* context) {
         }
     } else if(
         dev_data->protocol == NfcDeviceProtocolMifareClassic ||
+        dev_data->protocol == NfcDeviceProtocolMifareDesfire ||
         dev_data->protocol == NfcDeviceProtocolMifareUl) {
         furi_string_set(temp_str, nfc->dev->dev_data.parsed_data);
     }

applications/main/nfc/scenes/nfc_scene_mf_desfire_read_success.c

@@ -20,35 +20,40 @@ void nfc_scene_mf_desfire_read_success_on_enter(void* context) {
     Widget* widget = nfc->widget;
 
     // Prepare string for data display
-    FuriString* temp_str = furi_string_alloc_printf("\e#MIFARE DESfire\n");
-    furi_string_cat_printf(temp_str, "UID:");
-    for(size_t i = 0; i < nfc_data->uid_len; i++) {
-        furi_string_cat_printf(temp_str, " %02X", nfc_data->uid[i]);
-    }
-
-    uint32_t bytes_total = 1UL << (data->version.sw_storage >> 1);
-    uint32_t bytes_free = data->free_memory ? data->free_memory->bytes : 0;
-    furi_string_cat_printf(temp_str, "\n%lu", bytes_total);
-    if(data->version.sw_storage & 1) {
-        furi_string_push_back(temp_str, '+');
-    }
-    furi_string_cat_printf(temp_str, " bytes, %lu bytes free\n", bytes_free);
-
-    uint16_t n_apps = 0;
-    uint16_t n_files = 0;
-    for(MifareDesfireApplication* app = data->app_head; app; app = app->next) {
-        n_apps++;
-        for(MifareDesfireFile* file = app->file_head; file; file = file->next) {
-            n_files++;
+    FuriString* temp_str = NULL;
+    if(furi_string_size(nfc->dev->dev_data.parsed_data)) {
+        temp_str = furi_string_alloc_set(nfc->dev->dev_data.parsed_data);
+    } else {
+        temp_str = furi_string_alloc_printf("\e#MIFARE DESFire\n");
+        furi_string_cat_printf(temp_str, "UID:");
+        for(size_t i = 0; i < nfc_data->uid_len; i++) {
+            furi_string_cat_printf(temp_str, " %02X", nfc_data->uid[i]);
+        }
+
+        uint32_t bytes_total = 1UL << (data->version.sw_storage >> 1);
+        uint32_t bytes_free = data->free_memory ? data->free_memory->bytes : 0;
+        furi_string_cat_printf(temp_str, "\n%lu", bytes_total);
+        if(data->version.sw_storage & 1) {
+            furi_string_push_back(temp_str, '+');
+        }
+        furi_string_cat_printf(temp_str, " bytes, %lu bytes free\n", bytes_free);
+
+        uint16_t n_apps = 0;
+        uint16_t n_files = 0;
+        for(MifareDesfireApplication* app = data->app_head; app; app = app->next) {
+            n_apps++;
+            for(MifareDesfireFile* file = app->file_head; file; file = file->next) {
+                n_files++;
+            }
+        }
+        furi_string_cat_printf(temp_str, "%d Application", n_apps);
+        if(n_apps != 1) {
+            furi_string_push_back(temp_str, 's');
+        }
+        furi_string_cat_printf(temp_str, ", %d file", n_files);
+        if(n_files != 1) {
+            furi_string_push_back(temp_str, 's');
         }
-    }
-    furi_string_cat_printf(temp_str, "%d Application", n_apps);
-    if(n_apps != 1) {
-        furi_string_push_back(temp_str, 's');
-    }
-    furi_string_cat_printf(temp_str, ", %d file", n_files);
-    if(n_files != 1) {
-        furi_string_push_back(temp_str, 's');
     }
 
     notification_message_block(nfc->notifications, &sequence_set_green_255);

applications/main/nfc/scenes/nfc_scene_nfc_data_info.c

@@ -40,7 +40,7 @@ void nfc_scene_nfc_data_info_on_enter(void* context) {
         furi_string_cat_printf(
             temp_str, "\e#%s\n", nfc_mf_classic_type(dev_data->mf_classic_data.type));
     } else if(protocol == NfcDeviceProtocolMifareDesfire) {
-        furi_string_cat_printf(temp_str, "\e#MIFARE DESfire\n");
+        furi_string_cat_printf(temp_str, "\e#MIFARE DESFire\n");
     } else {
         furi_string_cat_printf(temp_str, "\e#Unknown ISO tag\n");
     }

applications/main/nfc/scenes/nfc_scene_saved_menu.c

@@ -148,6 +148,7 @@ bool nfc_scene_saved_menu_on_event(void* context, SceneManagerEvent event) {
                 application_info_present = true;
             } else if(
                 dev_data->protocol == NfcDeviceProtocolMifareClassic ||
+                dev_data->protocol == NfcDeviceProtocolMifareDesfire ||
                 dev_data->protocol == NfcDeviceProtocolMifareUl) {
                 application_info_present = nfc_supported_card_verify_and_parse(dev_data);
             }

firmware/targets/f18/api_symbols.csv

@@ -1,5 +1,5 @@
 entry,status,name,type,params
-Version,+,27.0,,
+Version,+,27.1,,
 Header,+,applications/services/bt/bt_service/bt.h,,
 Header,+,applications/services/cli/cli.h,,
 Header,+,applications/services/cli/cli_vcp.h,,
@@ -1048,6 +1048,8 @@ Function,+,furi_hal_rtc_datetime_to_timestamp,uint32_t,FuriHalRtcDateTime*
 Function,-,furi_hal_rtc_deinit_early,void,
 Function,+,furi_hal_rtc_get_boot_mode,FuriHalRtcBootMode,
 Function,+,furi_hal_rtc_get_datetime,void,FuriHalRtcDateTime*
+Function,+,furi_hal_rtc_get_days_per_month,uint8_t,"_Bool, uint8_t"
+Function,+,furi_hal_rtc_get_days_per_year,uint16_t,uint16_t
 Function,+,furi_hal_rtc_get_fault_data,uint32_t,
 Function,+,furi_hal_rtc_get_heap_track_mode,FuriHalRtcHeapTrackMode,
 Function,+,furi_hal_rtc_get_locale_dateformat,FuriHalRtcLocaleDateFormat,
@@ -1060,6 +1062,7 @@ Function,+,furi_hal_rtc_get_timestamp,uint32_t,
 Function,-,furi_hal_rtc_init,void,
 Function,-,furi_hal_rtc_init_early,void,
 Function,+,furi_hal_rtc_is_flag_set,_Bool,FuriHalRtcFlag
+Function,+,furi_hal_rtc_is_leap_year,_Bool,uint16_t
 Function,+,furi_hal_rtc_reset_flag,void,FuriHalRtcFlag
 Function,+,furi_hal_rtc_set_boot_mode,void,FuriHalRtcBootMode
 Function,+,furi_hal_rtc_set_datetime,void,FuriHalRtcDateTime*

firmware/targets/f7/api_symbols.csv

@@ -1,5 +1,5 @@
 entry,status,name,type,params
-Version,+,27.0,,
+Version,+,27.1,,
 Header,+,applications/services/bt/bt_service/bt.h,,
 Header,+,applications/services/cli/cli.h,,
 Header,+,applications/services/cli/cli_vcp.h,,
@@ -1313,6 +1313,8 @@ Function,+,furi_hal_rtc_datetime_to_timestamp,uint32_t,FuriHalRtcDateTime*
 Function,-,furi_hal_rtc_deinit_early,void,
 Function,+,furi_hal_rtc_get_boot_mode,FuriHalRtcBootMode,
 Function,+,furi_hal_rtc_get_datetime,void,FuriHalRtcDateTime*
+Function,+,furi_hal_rtc_get_days_per_month,uint8_t,"_Bool, uint8_t"
+Function,+,furi_hal_rtc_get_days_per_year,uint16_t,uint16_t
 Function,+,furi_hal_rtc_get_fault_data,uint32_t,
 Function,+,furi_hal_rtc_get_heap_track_mode,FuriHalRtcHeapTrackMode,
 Function,+,furi_hal_rtc_get_locale_dateformat,FuriHalRtcLocaleDateFormat,
@@ -1325,6 +1327,7 @@ Function,+,furi_hal_rtc_get_timestamp,uint32_t,
 Function,-,furi_hal_rtc_init,void,
 Function,-,furi_hal_rtc_init_early,void,
 Function,+,furi_hal_rtc_is_flag_set,_Bool,FuriHalRtcFlag
+Function,+,furi_hal_rtc_is_leap_year,_Bool,uint16_t
 Function,+,furi_hal_rtc_reset_flag,void,FuriHalRtcFlag
 Function,+,furi_hal_rtc_set_boot_mode,void,FuriHalRtcBootMode
 Function,+,furi_hal_rtc_set_datetime,void,FuriHalRtcDateTime*
@@ -1991,6 +1994,8 @@ Function,-,mf_df_cat_key_settings,void,"MifareDesfireKeySettings*, FuriString*"
 Function,-,mf_df_cat_version,void,"MifareDesfireVersion*, FuriString*"
 Function,-,mf_df_check_card_type,_Bool,"uint8_t, uint8_t, uint8_t"
 Function,-,mf_df_clear,void,MifareDesfireData*
+Function,-,mf_df_get_application,MifareDesfireApplication*,"MifareDesfireData*, const uint8_t[3]*"
+Function,-,mf_df_get_file,MifareDesfireFile*,"MifareDesfireApplication*, uint8_t"
 Function,-,mf_df_parse_get_application_ids_response,_Bool,"uint8_t*, uint16_t, MifareDesfireApplication**"
 Function,-,mf_df_parse_get_file_ids_response,_Bool,"uint8_t*, uint16_t, MifareDesfireFile**"
 Function,-,mf_df_parse_get_file_settings_response,_Bool,"uint8_t*, uint16_t, MifareDesfireFile*"

firmware/targets/f7/furi_hal/furi_hal_rtc.c

@@ -44,10 +44,8 @@ _Static_assert(sizeof(SystemReg) == 4, "SystemReg size mismatch");
 #define FURI_HAL_RTC_SECONDS_PER_DAY (FURI_HAL_RTC_SECONDS_PER_HOUR * 24)
 #define FURI_HAL_RTC_MONTHS_COUNT 12
 #define FURI_HAL_RTC_EPOCH_START_YEAR 1970
-#define FURI_HAL_RTC_IS_LEAP_YEAR(year) \
-    ((((year) % 4 == 0) && ((year) % 100 != 0)) || ((year) % 400 == 0))
 
-static const uint8_t furi_hal_rtc_days_per_month[][FURI_HAL_RTC_MONTHS_COUNT] = {
+static const uint8_t furi_hal_rtc_days_per_month[2][FURI_HAL_RTC_MONTHS_COUNT] = {
     {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31},
     {31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}};
 
@@ -395,7 +393,7 @@ uint32_t furi_hal_rtc_datetime_to_timestamp(FuriHalRtcDateTime* datetime) {
     uint8_t leap_years = 0;
 
     for(uint16_t y = FURI_HAL_RTC_EPOCH_START_YEAR; y < datetime->year; y++) {
-        if(FURI_HAL_RTC_IS_LEAP_YEAR(y)) {
+        if(furi_hal_rtc_is_leap_year(y)) {
             leap_years++;
         } else {
             years++;
@@ -406,10 +404,10 @@ uint32_t furi_hal_rtc_datetime_to_timestamp(FuriHalRtcDateTime* datetime) {
         ((years * furi_hal_rtc_days_per_year[0]) + (leap_years * furi_hal_rtc_days_per_year[1])) *
         FURI_HAL_RTC_SECONDS_PER_DAY;
 
-    uint8_t year_index = (FURI_HAL_RTC_IS_LEAP_YEAR(datetime->year)) ? 1 : 0;
+    bool leap_year = furi_hal_rtc_is_leap_year(datetime->year);
 
-    for(uint8_t m = 0; m < (datetime->month - 1); m++) {
-        timestamp += furi_hal_rtc_days_per_month[year_index][m] * FURI_HAL_RTC_SECONDS_PER_DAY;
+    for(uint8_t m = 1; m < datetime->month; m++) {
+        timestamp += furi_hal_rtc_get_days_per_month(leap_year, m) * FURI_HAL_RTC_SECONDS_PER_DAY;
     }
 
     timestamp += (datetime->day - 1) * FURI_HAL_RTC_SECONDS_PER_DAY;
@@ -419,3 +417,15 @@ uint32_t furi_hal_rtc_datetime_to_timestamp(FuriHalRtcDateTime* datetime) {
 
     return timestamp;
 }
+
+uint16_t furi_hal_rtc_get_days_per_year(uint16_t year) {
+    return furi_hal_rtc_days_per_year[furi_hal_rtc_is_leap_year(year) ? 1 : 0];
+}
+
+bool furi_hal_rtc_is_leap_year(uint16_t year) {
+    return (((year) % 4 == 0) && ((year) % 100 != 0)) || ((year) % 400 == 0);
+}
+
+uint8_t furi_hal_rtc_get_days_per_month(bool leap_year, uint8_t month) {
+    return furi_hal_rtc_days_per_month[leap_year ? 1 : 0][month - 1];
+}

firmware/targets/furi_hal_include/furi_hal_rtc.h

@@ -255,6 +255,30 @@ uint32_t furi_hal_rtc_get_timestamp();
  */
 uint32_t furi_hal_rtc_datetime_to_timestamp(FuriHalRtcDateTime* datetime);
 
+/** Gets the number of days in the year according to the Gregorian calendar.
+ *
+ * @param year Input year.
+ *
+ * @return number of days in `year`.
+ */
+uint16_t furi_hal_rtc_get_days_per_year(uint16_t year);
+
+/** Check if a year a leap year in the Gregorian calendar.
+ *
+ * @param year Input year.
+ *
+ * @return true if `year` is a leap year.
+ */
+bool furi_hal_rtc_is_leap_year(uint16_t year);
+
+/** Get the number of days in the month.
+ *
+ * @param leap_year true to calculate based on leap years
+ * @param month month to check, where 1 = January
+ * @return the number of days in the month
+ */
+uint8_t furi_hal_rtc_get_days_per_month(bool leap_year, uint8_t month);
+
 #ifdef __cplusplus
 }
 #endif

lib/nfc/nfc_worker.c

@@ -219,6 +219,19 @@ static bool nfc_worker_read_mf_desfire(NfcWorker* nfc_worker, FuriHalNfcTxRxCont
     do {
         if(!furi_hal_nfc_detect(&nfc_worker->dev_data->nfc_data, 300)) break;
         if(!mf_df_read_card(tx_rx, data)) break;
+        FURI_LOG_I(TAG, "Trying to parse a supported card ...");
+
+        // The model for parsing DESFire is a little different to other cards;
+        // we don't have parsers to provide encryption keys, so we can read the
+        // data normally, and then pass the read data to a parser.
+        //
+        // There are fully-protected DESFire cards, but providing keys for them
+        // is difficult (and unnessesary for many transit cards).
+        for(size_t i = 0; i < NfcSupportedCardTypeEnd; i++) {
+            if(nfc_supported_card[i].protocol == NfcDeviceProtocolMifareDesfire) {
+                if(nfc_supported_card[i].parse(nfc_worker->dev_data)) break;
+            }
+        }
         read_success = true;
     } while(false);
 

lib/nfc/parsers/nfc_supported_card.c

@@ -6,6 +6,7 @@
 #include "troika_4k_parser.h"
 #include "two_cities.h"
 #include "all_in_one.h"
+#include "opal.h"
 
 NfcSupportedCard nfc_supported_card[NfcSupportedCardTypeEnd] = {
     [NfcSupportedCardTypePlantain] =
@@ -50,6 +51,14 @@ NfcSupportedCard nfc_supported_card[NfcSupportedCardTypeEnd] = {
             .read = all_in_one_parser_read,
             .parse = all_in_one_parser_parse,
         },
+    [NfcSupportedCardTypeOpal] =
+        {
+            .protocol = NfcDeviceProtocolMifareDesfire,
+            .verify = stub_parser_verify_read,
+            .read = stub_parser_verify_read,
+            .parse = opal_parser_parse,
+        },
+
 };
 
 bool nfc_supported_card_verify_and_parse(NfcDeviceData* dev_data) {
@@ -65,3 +74,9 @@ bool nfc_supported_card_verify_and_parse(NfcDeviceData* dev_data) {
 
     return card_parsed;
 }
+
+bool stub_parser_verify_read(NfcWorker* nfc_worker, FuriHalNfcTxRxContext* tx_rx) {
+    UNUSED(nfc_worker);
+    UNUSED(tx_rx);
+    return false;
+}

lib/nfc/parsers/nfc_supported_card.h

@@ -11,6 +11,7 @@ typedef enum {
     NfcSupportedCardTypeTroika4K,
     NfcSupportedCardTypeTwoCities,
     NfcSupportedCardTypeAllInOne,
+    NfcSupportedCardTypeOpal,
 
     NfcSupportedCardTypeEnd,
 } NfcSupportedCardType;
@@ -31,3 +32,8 @@ typedef struct {
 extern NfcSupportedCard nfc_supported_card[NfcSupportedCardTypeEnd];
 
 bool nfc_supported_card_verify_and_parse(NfcDeviceData* dev_data);
+
+// stub_parser_verify_read does nothing, and always reports that it does not
+// support the card. This is needed for DESFire card parsers which can't
+// provide keys, and only use NfcSupportedCard->parse.
+bool stub_parser_verify_read(NfcWorker* nfc_worker, FuriHalNfcTxRxContext* tx_rx);

lib/nfc/parsers/opal.c

@@ -0,0 +1,204 @@
+/*
+ * opal.c - Parser for Opal card (Sydney, Australia).
+ *
+ * Copyright 2023 Michael Farrell <micolous+git@gmail.com>
+ *
+ * This will only read "standard" MIFARE DESFire-based Opal cards. Free travel
+ * cards (including School Opal cards, veteran, vision-impaired persons and
+ * TfNSW employees' cards) and single-trip tickets are MIFARE Ultralight C
+ * cards and not supported.
+ *
+ * Reference: https://github.com/metrodroid/metrodroid/wiki/Opal
+ *
+ * Note: The card values are all little-endian (like Flipper), but the above
+ * reference was originally written based on Java APIs, which are big-endian.
+ * This implementation presumes a little-endian system.
+ *
+ * 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 "nfc_supported_card.h"
+#include "opal.h"
+
+#include <applications/services/locale/locale.h>
+#include <gui/modules/widget.h>
+#include <nfc_worker_i.h>
+
+#include <furi_hal.h>
+
+static const uint8_t opal_aid[3] = {0x31, 0x45, 0x53};
+static const char* opal_modes[5] =
+    {"Rail / Metro", "Ferry / Light Rail", "Bus", "Unknown mode", "Manly Ferry"};
+static const char* opal_usages[14] = {
+    "New / Unused",
+    "Tap on: new journey",
+    "Tap on: transfer from same mode",
+    "Tap on: transfer from other mode",
+    "", // Manly Ferry: new journey
+    "", // Manly Ferry: transfer from ferry
+    "", // Manly Ferry: transfer from other
+    "Tap off: distance fare",
+    "Tap off: flat fare",
+    "Automated tap off: failed to tap off",
+    "Tap off: end of trip without start",
+    "Tap off: reversal",
+    "Tap on: rejected",
+    "Unknown usage",
+};
+
+// Opal file 0x7 structure. Assumes a little-endian CPU.
+typedef struct __attribute__((__packed__)) {
+    uint32_t serial : 32;
+    uint8_t check_digit : 4;
+    bool blocked : 1;
+    uint16_t txn_number : 16;
+    int32_t balance : 21;
+    uint16_t days : 15;
+    uint16_t minutes : 11;
+    uint8_t mode : 3;
+    uint16_t usage : 4;
+    bool auto_topup : 1;
+    uint8_t weekly_journeys : 4;
+    uint16_t checksum : 16;
+} OpalFile;
+
+static_assert(sizeof(OpalFile) == 16);
+
+// Converts an Opal timestamp to FuriHalRtcDateTime.
+//
+// Opal measures days since 1980-01-01 and minutes since midnight, and presumes
+// all days are 1440 minutes.
+void opal_date_time_to_furi(uint16_t days, uint16_t minutes, FuriHalRtcDateTime* out) {
+    if(!out) return;
+    uint16_t diy;
+    out->year = 1980;
+    out->month = 1;
+    // 1980-01-01 is a Tuesday
+    out->weekday = ((days + 1) % 7) + 1;
+    out->hour = minutes / 60;
+    out->minute = minutes % 60;
+    out->second = 0;
+
+    // What year is it?
+    for(;;) {
+        diy = furi_hal_rtc_get_days_per_year(out->year);
+        if(days < diy) break;
+        days -= diy;
+        out->year++;
+    }
+
+    // 1-index the day of the year
+    days++;
+    // What month is it?
+    bool is_leap = furi_hal_rtc_is_leap_year(out->year);
+
+    for(;;) {
+        uint8_t dim = furi_hal_rtc_get_days_per_month(is_leap, out->month);
+        if(days <= dim) break;
+        days -= dim;
+        out->month++;
+    }
+
+    out->day = days;
+}
+
+bool opal_parser_parse(NfcDeviceData* dev_data) {
+    if(dev_data->protocol != NfcDeviceProtocolMifareDesfire) {
+        return false;
+    }
+
+    MifareDesfireApplication* app = mf_df_get_application(&dev_data->mf_df_data, &opal_aid);
+    if(app == NULL) {
+        return false;
+    }
+    MifareDesfireFile* f = mf_df_get_file(app, 0x07);
+    if(f == NULL || f->type != MifareDesfireFileTypeStandard || f->settings.data.size != 16 ||
+       !f->contents) {
+        return false;
+    }
+
+    OpalFile* o = (OpalFile*)f->contents;
+
+    uint8_t serial2 = o->serial / 10000000;
+    uint16_t serial3 = (o->serial / 1000) % 10000;
+    uint16_t serial4 = (o->serial % 1000);
+
+    if(o->check_digit > 9) {
+        return false;
+    }
+
+    char* sign = "";
+    if(o->balance < 0) {
+        // Negative balance. Make this a positive value again and record the
+        // sign separately, because then we can handle balances of -99..-1
+        // cents, as the "dollars" division below would result in a positive
+        // zero value.
+        o->balance = abs(o->balance);
+        sign = "-";
+    }
+    uint8_t cents = o->balance % 100;
+    int32_t dollars = o->balance / 100;
+
+    FuriHalRtcDateTime timestamp;
+    opal_date_time_to_furi(o->days, o->minutes, &timestamp);
+
+    if(o->mode >= 3) {
+        // 3..7 are "reserved", but we use 4 to indicate the Manly Ferry.
+        o->mode = 3;
+    }
+
+    if(o->usage >= 4 && o->usage <= 6) {
+        // Usages 4..6 associated with the Manly Ferry, which correspond to
+        // usages 1..3 for other modes.
+        o->usage -= 3;
+        o->mode = 4;
+    }
+
+    const char* mode_str = (o->mode <= 4 ? opal_modes[o->mode] : opal_modes[3]);
+    const char* usage_str = (o->usage <= 12 ? opal_usages[o->usage] : opal_usages[13]);
+
+    furi_string_printf(
+        dev_data->parsed_data,
+        "\e#Opal: $%s%ld.%02hu\n3085 22%02hhu %04hu %03hu%01hhu\n%s, %s\n",
+        sign,
+        dollars,
+        cents,
+        serial2,
+        serial3,
+        serial4,
+        o->check_digit,
+        mode_str,
+        usage_str);
+    FuriString* timestamp_str = furi_string_alloc();
+    locale_format_date(timestamp_str, &timestamp, locale_get_date_format(), "-");
+    furi_string_cat(dev_data->parsed_data, timestamp_str);
+    furi_string_cat_str(dev_data->parsed_data, " at ");
+
+    locale_format_time(timestamp_str, &timestamp, locale_get_time_format(), false);
+    furi_string_cat(dev_data->parsed_data, timestamp_str);
+
+    furi_string_free(timestamp_str);
+    furi_string_cat_printf(
+        dev_data->parsed_data,
+        "\nWeekly journeys: %hhu, Txn #%hu\n",
+        o->weekly_journeys,
+        o->txn_number);
+
+    if(o->auto_topup) {
+        furi_string_cat_str(dev_data->parsed_data, "Auto-topup enabled\n");
+    }
+    if(o->blocked) {
+        furi_string_cat_str(dev_data->parsed_data, "Card blocked\n");
+    }
+    return true;
+}

lib/nfc/parsers/opal.h

@@ -0,0 +1,5 @@
+#pragma once
+
+#include "nfc_supported_card.h"
+
+bool opal_parser_parse(NfcDeviceData* dev_data);

lib/nfc/protocols/mifare_desfire.c

@@ -42,6 +42,30 @@ void mf_df_clear(MifareDesfireData* data) {
     data->app_head = NULL;
 }
 
+MifareDesfireApplication* mf_df_get_application(MifareDesfireData* data, const uint8_t (*aid)[3]) {
+    if(!data) {
+        return NULL;
+    }
+    for(MifareDesfireApplication* app = data->app_head; app; app = app->next) {
+        if(memcmp(aid, app->id, 3) == 0) {
+            return app;
+        }
+    }
+    return NULL;
+}
+
+MifareDesfireFile* mf_df_get_file(MifareDesfireApplication* app, uint8_t id) {
+    if(!app) {
+        return NULL;
+    }
+    for(MifareDesfireFile* file = app->file_head; file; file = file->next) {
+        if(file->id == id) {
+            return file;
+        }
+    }
+    return NULL;
+}
+
 void mf_df_cat_data(MifareDesfireData* data, FuriString* out) {
     mf_df_cat_card_info(data, out);
     for(MifareDesfireApplication* app = data->app_head; app; app = app->next) {

lib/nfc/protocols/mifare_desfire.h

@@ -130,6 +130,9 @@ void mf_df_cat_file(MifareDesfireFile* file, FuriString* out);
 
 bool mf_df_check_card_type(uint8_t ATQA0, uint8_t ATQA1, uint8_t SAK);
 
+MifareDesfireApplication* mf_df_get_application(MifareDesfireData* data, const uint8_t (*aid)[3]);
+MifareDesfireFile* mf_df_get_file(MifareDesfireApplication* app, uint8_t id);
+
 uint16_t mf_df_prepare_get_version(uint8_t* dest);
 bool mf_df_parse_get_version_response(uint8_t* buf, uint16_t len, MifareDesfireVersion* out);