Nfc: HID MFC Plugin (#3312)

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

applications/main/nfc/application.fam

@@ -101,6 +101,15 @@ App(
     sources=["plugins/supported_cards/umarsh.c"],
 )
 
+App(
+    appid="hid_parser",
+    apptype=FlipperAppType.PLUGIN,
+    entry_point="hid_plugin_ep",
+    targets=["f7"],
+    requires=["nfc"],
+    sources=["plugins/supported_cards/hid.c"],
+)
+
 App(
     appid="nfc_start",
     targets=["f7"],

applications/main/nfc/plugins/supported_cards/hid.c

@@ -0,0 +1,153 @@
+#include "nfc_supported_card_plugin.h"
+
+#include <flipper_application/flipper_application.h>
+
+#include <nfc/nfc_device.h>
+#include <nfc/helpers/nfc_util.h>
+#include <nfc/protocols/mf_classic/mf_classic_poller_sync.h>
+
+#define TAG "HID"
+
+static const uint64_t hid_key = 0x484944204953;
+
+bool hid_verify(Nfc* nfc) {
+    bool verified = false;
+
+    do {
+        const uint8_t verify_sector = 1;
+        uint8_t block_num = mf_classic_get_first_block_num_of_sector(verify_sector);
+        FURI_LOG_D(TAG, "Verifying sector %u", verify_sector);
+
+        MfClassicKey key = {};
+        nfc_util_num2bytes(hid_key, COUNT_OF(key.data), key.data);
+
+        MfClassicAuthContext auth_ctx = {};
+        MfClassicError error =
+            mf_classic_poller_sync_auth(nfc, block_num, &key, MfClassicKeyTypeA, &auth_ctx);
+
+        if(error != MfClassicErrorNone) {
+            FURI_LOG_D(TAG, "Failed to read block %u: %d", block_num, error);
+            break;
+        }
+
+        verified = true;
+    } while(false);
+
+    return verified;
+}
+
+static bool hid_read(Nfc* nfc, NfcDevice* device) {
+    furi_assert(nfc);
+    furi_assert(device);
+
+    bool is_read = false;
+
+    MfClassicData* data = mf_classic_alloc();
+    nfc_device_copy_data(device, NfcProtocolMfClassic, data);
+
+    do {
+        MfClassicType type = MfClassicType1k;
+        MfClassicError error = mf_classic_poller_sync_detect_type(nfc, &type);
+        if(error != MfClassicErrorNone) break;
+
+        data->type = type;
+        MfClassicDeviceKeys keys = {};
+        for(size_t i = 0; i < mf_classic_get_total_sectors_num(data->type); i++) {
+            nfc_util_num2bytes(hid_key, sizeof(MfClassicKey), keys.key_a[i].data);
+            FURI_BIT_SET(keys.key_a_mask, i);
+            nfc_util_num2bytes(hid_key, sizeof(MfClassicKey), keys.key_b[i].data);
+            FURI_BIT_SET(keys.key_b_mask, i);
+        }
+
+        error = mf_classic_poller_sync_read(nfc, &keys, data);
+        if(error != MfClassicErrorNone) {
+            FURI_LOG_W(TAG, "Failed to read data");
+            break;
+        }
+
+        nfc_device_set_data(device, NfcProtocolMfClassic, data);
+
+        is_read = true;
+    } while(false);
+
+    mf_classic_free(data);
+
+    return is_read;
+}
+
+static uint8_t get_bit_length(const uint8_t* half_block) {
+    uint8_t bitLength = 0;
+    uint32_t* halves = (uint32_t*)half_block;
+    if(halves[0] == 0) {
+        uint8_t leading0s = __builtin_clz(REVERSE_BYTES_U32(halves[1]));
+        bitLength = 31 - leading0s;
+    } else {
+        uint8_t leading0s = __builtin_clz(REVERSE_BYTES_U32(halves[0]));
+        bitLength = 63 - leading0s;
+    }
+
+    return bitLength;
+}
+
+static uint64_t get_pacs_bits(const uint8_t* block, uint8_t bitLength) {
+    // Remove sentinel bit from credential.  Byteswapping to handle array of bytes vs 64bit value
+    uint64_t sentinel = __builtin_bswap64(1ULL << bitLength);
+    uint64_t swapped = 0;
+    memcpy(&swapped, block, sizeof(uint64_t));
+    swapped = __builtin_bswap64(swapped ^ sentinel);
+    FURI_LOG_D(TAG, "PACS: (%d) %016llx", bitLength, swapped);
+    return swapped;
+}
+
+static bool hid_parse(const NfcDevice* device, FuriString* parsed_data) {
+    furi_assert(device);
+
+    const MfClassicData* data = nfc_device_get_data(device, NfcProtocolMfClassic);
+
+    bool parsed = false;
+
+    do {
+        // verify key
+        const uint8_t verify_sector = 1;
+        MfClassicSectorTrailer* sec_tr =
+            mf_classic_get_sector_trailer_by_sector(data, verify_sector);
+        uint64_t key = nfc_util_bytes2num(sec_tr->key_a.data, 6);
+        if(key != hid_key) break;
+
+        // Currently doesn't support bit length > 63
+        const uint8_t* credential_block = data->block[5].data + 8;
+
+        uint8_t bitLength = get_bit_length(credential_block);
+        if(bitLength == 0) break;
+
+        uint64_t credential = get_pacs_bits(credential_block, bitLength);
+        if(credential == 0) break;
+
+        furi_string_printf(parsed_data, "\e#HID Card\n%dbit\n%llx", bitLength, credential);
+
+        parsed = true;
+
+    } while(false);
+
+    return parsed;
+}
+
+/* Actual implementation of app<>plugin interface */
+static const NfcSupportedCardsPlugin hid_plugin = {
+    .protocol = NfcProtocolMfClassic,
+    .verify = hid_verify,
+    .read = hid_read,
+    .parse = hid_parse,
+};
+
+/* Plugin descriptor to comply with basic plugin specification */
+static const FlipperAppPluginDescriptor hid_plugin_descriptor = {
+    .appid = NFC_SUPPORTED_CARD_PLUGIN_APP_ID,
+    .ep_api_version = NFC_SUPPORTED_CARD_PLUGIN_API_VERSION,
+    .entry_point = &hid_plugin,
+};
+
+/* Plugin entry point - must return a pointer to const descriptor  */
+const FlipperAppPluginDescriptor* hid_plugin_ep() {
+    return &hid_plugin_descriptor;
+}