[FL-2245] Introduce Mifare Classic Emulation (#1242)

* digital signal: introduce digital signal
* nfca: add nfca signal encoder
* nfc: add mifare classic emulation scene
* nfca: add classic emulation support to lib and hal
* mifare classic: support basic read commands
* nfc: add mifare classic menu scene
* mifare classic: start parsing commands in emulation
* mifare classic: add nested auth
* nfc: fix errors
* mifare classic: add encrypt function
* nfc: fix mifare classic save
* lib hex: add hex uint64_t ASCII parser
* flipper format: add uint64 hex format support
* nfc: add mifare classic key map
* nfc: hide mifare classic keys on emulation
* mifare classic: add NACK responce
* nfc: add partial bytes support in transparent mode
* nfc: mifare classic add shadow file support
* digital signal: move arr buffer from BSS to heap
* mifare classic: process access bits more careful
* nfca: fix memory leack
* nfc: format sources
* mifare classic: cleun up

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

lib/nfc_protocols/nfca.c

@@ -1,11 +1,17 @@
 #include "nfca.h"
 #include <string.h>
 #include <stdio.h>
+#include <furi.h>
 
 #define NFCA_CMD_RATS (0xE0U)
 
 #define NFCA_CRC_INIT (0x6363)
 
+#define NFCA_F_SIG (13560000.0)
+#define NFCA_T_SIG (1.0 / NFCA_F_SIG)
+
+#define NFCA_SIGNAL_MAX_EDGES (1350)
+
 typedef struct {
     uint8_t cmd;
     uint8_t param;
@@ -53,3 +59,81 @@ bool nfca_emulation_handler(
 
     return sleep;
 }
+
+static void nfca_add_bit(DigitalSignal* signal, bool bit) {
+    if(bit) {
+        signal->start_level = true;
+        for(size_t i = 0; i < 7; i++) {
+            signal->edge_timings[i] = 8 * NFCA_T_SIG;
+        }
+        signal->edge_timings[7] = 9 * 8 * NFCA_T_SIG;
+        signal->edge_cnt = 8;
+    } else {
+        signal->start_level = false;
+        signal->edge_timings[0] = 8 * 8 * NFCA_T_SIG;
+        for(size_t i = 1; i < 9; i++) {
+            signal->edge_timings[i] = 8 * NFCA_T_SIG;
+        }
+        signal->edge_cnt = 9;
+    }
+}
+
+static void nfca_add_byte(NfcaSignal* nfca_signal, uint8_t byte, bool parity) {
+    for(uint8_t i = 0; i < 8; i++) {
+        if(byte & (1 << i)) {
+            digital_signal_append(nfca_signal->tx_signal, nfca_signal->one);
+        } else {
+            digital_signal_append(nfca_signal->tx_signal, nfca_signal->zero);
+        }
+    }
+    if(parity) {
+        digital_signal_append(nfca_signal->tx_signal, nfca_signal->one);
+    } else {
+        digital_signal_append(nfca_signal->tx_signal, nfca_signal->zero);
+    }
+}
+
+NfcaSignal* nfca_signal_alloc() {
+    NfcaSignal* nfca_signal = malloc(sizeof(NfcaSignal));
+    nfca_signal->one = digital_signal_alloc(10);
+    nfca_signal->zero = digital_signal_alloc(10);
+    nfca_add_bit(nfca_signal->one, true);
+    nfca_add_bit(nfca_signal->zero, false);
+    nfca_signal->tx_signal = digital_signal_alloc(NFCA_SIGNAL_MAX_EDGES);
+
+    return nfca_signal;
+}
+
+void nfca_signal_free(NfcaSignal* nfca_signal) {
+    furi_assert(nfca_signal);
+
+    digital_signal_free(nfca_signal->one);
+    digital_signal_free(nfca_signal->zero);
+    digital_signal_free(nfca_signal->tx_signal);
+    free(nfca_signal);
+}
+
+void nfca_signal_encode(NfcaSignal* nfca_signal, uint8_t* data, uint16_t bits, uint8_t* parity) {
+    furi_assert(nfca_signal);
+    furi_assert(data);
+    furi_assert(parity);
+
+    nfca_signal->tx_signal->edge_cnt = 0;
+    nfca_signal->tx_signal->start_level = true;
+    // Start of frame
+    digital_signal_append(nfca_signal->tx_signal, nfca_signal->one);
+
+    if(bits < 8) {
+        for(size_t i = 0; i < bits; i++) {
+            if(FURI_BIT(data[0], i)) {
+                digital_signal_append(nfca_signal->tx_signal, nfca_signal->one);
+            } else {
+                digital_signal_append(nfca_signal->tx_signal, nfca_signal->zero);
+            }
+        }
+    } else {
+        for(size_t i = 0; i < bits / 8; i++) {
+            nfca_add_byte(nfca_signal, data[i], parity[i / 8] & (1 << (7 - (i & 0x07))));
+        }
+    }
+}