upd pr 4316

with features flags fix
todo: proper workaround for NfcProtocolFeatureEmulateUid

Author: xMasterX

applications/main/nfc/helpers/protocol_support/mf_classic/mf_classic.c

@@ -204,7 +204,14 @@ static void nfc_scene_saved_menu_on_enter_mf_classic(NfcApp* instance) {
 }
 
 static void nfc_scene_emulate_on_enter_mf_classic(NfcApp* instance) {
-    const MfClassicData* data = nfc_device_get_data(instance->nfc_device, NfcProtocolMfClassic);
+    // Use stored data; normalize ATQA/SAK in-place for 4-byte UID to avoid cascade-bit issues
+    MfClassicData* data =
+        (MfClassicData*)nfc_device_get_data(instance->nfc_device, NfcProtocolMfClassic);
+    if(data->iso14443_3a_data && data->iso14443_3a_data->uid_len == 4) {
+        data->iso14443_3a_data->atqa[0] = 0x04;
+        data->iso14443_3a_data->atqa[1] = 0x00;
+        data->iso14443_3a_data->sak = 0x08; // no cascade bit
+    }
     instance->listener = nfc_listener_alloc(instance->nfc, NfcProtocolMfClassic, data);
     nfc_listener_start(instance->listener, NULL, NULL);
 }

applications/main/nfc/helpers/protocol_support/mf_plus/mf_plus.c

@@ -2,8 +2,13 @@
 #include "mf_plus_render.h"
 
 #include <nfc/protocols/mf_plus/mf_plus_poller.h>
+#include <nfc/protocols/mf_classic/mf_classic.h>
+
+#include <string.h>
+#include <lib/bit_lib/bit_lib.h>
 
 #include "nfc/nfc_app_i.h"
+#include "../../mf_classic_key_cache.h"
 
 #include "../nfc_protocol_support_common.h"
 #include "../nfc_protocol_support_gui_common.h"
@@ -82,17 +87,143 @@ static void nfc_scene_read_success_on_enter_mf_plus(NfcApp* instance) {
 }
 
 static void nfc_scene_emulate_on_enter_mf_plus(NfcApp* instance) {
-    const Iso14443_4aData* iso14443_4a_data =
-        nfc_device_get_data(instance->nfc_device, NfcProtocolIso14443_4a);
+    const MfPlusData* mf_plus_data = nfc_device_get_data(instance->nfc_device, NfcProtocolMfPlus);
+
+    // For SL1 2K cards, use Classic emulation (compatible with Classic readers)
+    // MIFARE Plus 2K SL1 emulates as Classic with 32 sectors (128 blocks total)
+    // This allows UID-only readers (like printers) to work, and exposes all 32 sectors
+    if(mf_plus_data->security_level == MfPlusSecurityLevel1 &&
+       mf_plus_data->size == MfPlusSize2K) {
+        MfClassicData* classic_data = NULL;
+
+        // Try to get Classic data if the card was read as Classic
+        // This ensures we emulate the actual data that was scanned (all sectors, keys, blocks)
+        const MfClassicData* existing_classic_data = NULL;
+        // Check if device protocol is Classic (card was read as Classic, not just Plus)
+        if(nfc_device_get_protocol(instance->nfc_device) == NfcProtocolMfClassic) {
+            existing_classic_data =
+                nfc_device_get_data(instance->nfc_device, NfcProtocolMfClassic);
+        }
+
+        if(existing_classic_data && existing_classic_data->type == MfClassicTypePlus2k) {
+            // Use the actual Classic data that was read from the card
+            // This contains all the real sector data, keys, and blocks from the scan
+            classic_data = mf_classic_alloc();
+            mf_classic_copy(classic_data, existing_classic_data);
+
+            // Ensure sectors 18-31 are treated as uninitialized to match real card behavior
+            // On real MIFARE Plus 2K SL1 cards, sectors 18-31 are typically empty/uninitialized
+            // Clear key masks for sectors 18-31 if keys are zero (uninitialized)
+            for(uint8_t sector = 18; sector < 32; sector++) {
+                uint8_t sector_trailer_block = sector * 4 + 3;
+                MfClassicSectorTrailer* sec_tr =
+                    (MfClassicSectorTrailer*)&classic_data->block[sector_trailer_block];
+
+                // Check if both keys are zero (uninitialized)
+                bool key_a_zero = true;
+                bool key_b_zero = true;
+                for(int i = 0; i < 6; i++) {
+                    if(sec_tr->key_a.data[i] != 0) key_a_zero = false;
+                    if(sec_tr->key_b.data[i] != 0) key_b_zero = false;
+                }
+
+                // Check if keys were found in original read
+                bool key_a_found_orig =
+                    mf_classic_is_key_found(existing_classic_data, sector, MfClassicKeyTypeA);
+                bool key_b_found_orig =
+                    mf_classic_is_key_found(existing_classic_data, sector, MfClassicKeyTypeB);
 
-    instance->listener =
-        nfc_listener_alloc(instance->nfc, NfcProtocolIso14443_4a, iso14443_4a_data);
-    nfc_listener_start(
-        instance->listener, nfc_scene_emulate_listener_callback_iso14443_4a, instance);
+                // Clear key masks if keys are zero (uninitialized) OR if they weren't found in original
+                // This ensures empty sectors appear as uninitialized, matching real card
+                // The listener will reject authentication attempts to sectors without keys found
+                if(key_a_zero || !key_a_found_orig) {
+                    mf_classic_set_key_not_found(classic_data, sector, MfClassicKeyTypeA);
+                }
+                if(key_b_zero || !key_b_found_orig) {
+                    mf_classic_set_key_not_found(classic_data, sector, MfClassicKeyTypeB);
+                }
+            }
+        } else {
+            // No Classic data available - create minimal Classic data from MF Plus
+            // This is a fallback when card was only read as Plus (without sector data)
+            classic_data = mf_classic_alloc();
+            classic_data->type = MfClassicTypePlus2k;
+
+            // Initialize key masks to zero (no keys found) - sectors are uninitialized
+            classic_data->key_a_mask = 0ULL;
+            classic_data->key_b_mask = 0ULL;
+
+            // Copy ISO14443-3A data from MF Plus (UID, ATQA, SAK)
+            const Iso14443_3aData* iso3_data =
+                iso14443_4a_get_base_data(mf_plus_data->iso14443_4a_data);
+            if(iso3_data) {
+                iso14443_3a_copy(classic_data->iso14443_3a_data, iso3_data);
+                // Force SL1 Classic view: ATQA 0x0004, SAK 0x08 (no cascade bit)
+                classic_data->iso14443_3a_data->atqa[0] = 0x04;
+                classic_data->iso14443_3a_data->atqa[1] = 0x00;
+                classic_data->iso14443_3a_data->sak = 0x08;
+                // Ensure 4-byte UID form (the real card uses 4B UID)
+                if(classic_data->iso14443_3a_data->uid_len > 4) {
+                    classic_data->iso14443_3a_data->uid_len = 4;
+                }
+
+                // Try to load keys from key cache to speed up emulation
+                // This allows emulation to work faster if keys were previously cached
+                if(instance->mfc_key_cache) {
+                    size_t uid_len = 0;
+                    const uint8_t* uid = iso14443_3a_get_uid(iso3_data, &uid_len);
+                    if(mf_classic_key_cache_load(instance->mfc_key_cache, uid, uid_len)) {
+                        // Keys loaded from cache - copy them to classic_data
+                        MfClassicDeviceKeys* cached_keys = &instance->mfc_key_cache->keys;
+                        classic_data->key_a_mask = cached_keys->key_a_mask;
+                        classic_data->key_b_mask = cached_keys->key_b_mask;
+
+                        // Copy cached keys to sector trailers
+                        for(uint8_t sector = 0; sector < 32; sector++) {
+                            if(FURI_BIT(cached_keys->key_a_mask, sector)) {
+                                MfClassicSectorTrailer* sec_tr =
+                                    mf_classic_get_sector_trailer_by_sector(classic_data, sector);
+                                sec_tr->key_a = cached_keys->key_a[sector];
+                                mf_classic_set_key_found(
+                                    classic_data,
+                                    sector,
+                                    MfClassicKeyTypeA,
+                                    bit_lib_bytes_to_num_be(cached_keys->key_a[sector].data, 6));
+                            }
+                            if(FURI_BIT(cached_keys->key_b_mask, sector)) {
+                                MfClassicSectorTrailer* sec_tr =
+                                    mf_classic_get_sector_trailer_by_sector(classic_data, sector);
+                                sec_tr->key_b = cached_keys->key_b[sector];
+                                mf_classic_set_key_found(
+                                    classic_data,
+                                    sector,
+                                    MfClassicKeyTypeB,
+                                    bit_lib_bytes_to_num_be(cached_keys->key_b[sector].data, 6));
+                            }
+                        }
+                    }
+                }
+            }
+            // Note: Without Classic data, sectors without cached keys are uninitialized (no keys found)
+            // This matches real card behavior for empty sectors
+        }
+
+        instance->listener = nfc_listener_alloc(instance->nfc, NfcProtocolMfClassic, classic_data);
+        nfc_listener_start(instance->listener, NULL, NULL);
+    } else {
+        // For SL2/SL3, use ISO14443-4A emulation
+        const Iso14443_4aData* iso14443_4a_data =
+            nfc_device_get_data(instance->nfc_device, NfcProtocolIso14443_4a);
+
+        instance->listener =
+            nfc_listener_alloc(instance->nfc, NfcProtocolIso14443_4a, iso14443_4a_data);
+        nfc_listener_start(
+            instance->listener, nfc_scene_emulate_listener_callback_iso14443_4a, instance);
+    }
 }
 
 const NfcProtocolSupportBase nfc_protocol_support_mf_plus = {
-    .features = NfcProtocolFeatureEmulateUid | NfcProtocolFeatureMoreInfo,
+    .features = NfcProtocolFeatureEmulateFull | NfcProtocolFeatureMoreInfo,
 
     .scene_info =
         {

lib/nfc/protocols/mf_classic/mf_classic.c

@@ -16,7 +16,8 @@ typedef struct {
 
 static const uint32_t mf_classic_data_format_version = 2;
 
-#define MF_CLASSIC_PLUS2K_SCAN_SECTORS 18
+// MIFARE Plus 2K SL1 has 32 sectors (128 blocks total) per official specification
+#define MF_CLASSIC_PLUS2K_SCAN_SECTORS 32
 
 static const MfClassicFeatures mf_classic_features[MfClassicTypeNum] = {
     [MfClassicTypeMini] =

lib/nfc/protocols/mf_classic/mf_classic_listener.c

@@ -65,6 +65,15 @@ static MfClassicListenerCommand mf_classic_listener_auth_first_part_handler(
 
         uint8_t sector_num = mf_classic_get_sector_by_block(block_num);
 
+        // Reject authentication immediately if keys are not found (uninitialized sector)
+        // This matches real card behavior where empty sectors reject authentication
+        // Fast path: check mask directly instead of function call
+        if(key_type == MfClassicKeyTypeA) {
+            if(FURI_BIT(instance->data->key_a_mask, sector_num) == 0) break;
+        } else {
+            if(FURI_BIT(instance->data->key_b_mask, sector_num) == 0) break;
+        }
+
         MfClassicSectorTrailer* sec_tr =
             mf_classic_get_sector_trailer_by_sector(instance->data, sector_num);
         MfClassicKey* key = (key_type == MfClassicKeyTypeA) ? &sec_tr->key_a : &sec_tr->key_b;