From 71035dc3ae84aaa9b77a0860c384e2f8945dea5a Mon Sep 17 00:00:00 2001
From: Yukai Li <yukaili.geek@gmail.com>
Date: Tue, 26 Jul 2022 12:29:17 -0600
Subject: [PATCH] nfc: Add NTAG authentication event to emulation

---
 lib/nfc/nfc_worker.c                  | 9 +++++++++
 lib/nfc/nfc_worker.h                  | 2 +-
 lib/nfc/protocols/mifare_ultralight.c | 8 ++++++++
 lib/nfc/protocols/mifare_ultralight.h | 2 ++
 4 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/lib/nfc/nfc_worker.c b/lib/nfc/nfc_worker.c
index aa81e55c2..c33f2fa2a 100644
--- a/lib/nfc/nfc_worker.c
+++ b/lib/nfc/nfc_worker.c
@@ -447,6 +447,15 @@ void nfc_worker_emulate_mf_ultralight(NfcWorker* nfc_worker) {
             mf_ul_prepare_emulation_response,
             &emulator,
             5000);
+        // Check if there was an auth attempt
+        if(emulator.auth_attempted) {
+            nfc_worker->event_data = &emulator.auth_attempt;
+            if(nfc_worker->callback) {
+                nfc_worker->callback(NfcWorkerEventPwdAuth, nfc_worker->context);
+            }
+            emulator.auth_attempted = false;
+            nfc_worker->event_data = NULL;
+        }
         // Check if data was modified
         if(emulator.data_changed) {
             nfc_worker->dev_data->mf_ul_data = emulator.data;
diff --git a/lib/nfc/nfc_worker.h b/lib/nfc/nfc_worker.h
index 1f4ed7eb6..ef5213ad7 100644
--- a/lib/nfc/nfc_worker.h
+++ b/lib/nfc/nfc_worker.h
@@ -62,7 +62,7 @@ typedef enum {
 
     // Mifare Ultralight events
     NfcWorkerEventMfUltralightPassKey,
-
+    NfcWorkerEventPwdAuth,
 } NfcWorkerEvent;
 
 typedef bool (*NfcWorkerCallback)(NfcWorkerEvent event, void* context);
diff --git a/lib/nfc/protocols/mifare_ultralight.c b/lib/nfc/protocols/mifare_ultralight.c
index d53b4d2e0..c11ebf77c 100644
--- a/lib/nfc/protocols/mifare_ultralight.c
+++ b/lib/nfc/protocols/mifare_ultralight.c
@@ -1246,6 +1246,7 @@ void mf_ul_prepare_emulation(MfUltralightEmulator* emulator, MfUltralightData* d
     emulator->config = mf_ultralight_get_config_pages(&emulator->data);
     emulator->page_num = emulator->data.data_size / 4;
     emulator->data_changed = false;
+    memset(&emulator->auth_attempt, 0, sizeof(MfUltralightAuth));
     mf_ul_reset_emulation(emulator, true);
 }
 
@@ -1706,6 +1707,13 @@ bool mf_ul_prepare_emulation_response(
         } else if(cmd == MF_UL_AUTH) {
             if(emulator->supported_features & MfUltralightSupportAuth) {
                 if(buff_rx_len == (1 + 4) * 8) {
+                    // Record password sent by PCD
+                    memcpy(
+                        emulator->auth_attempt.pwd.raw,
+                        &buff_rx[1],
+                        sizeof(emulator->auth_attempt.pwd.raw));
+                    emulator->auth_attempted = true;
+                    
                     uint16_t scaled_authlim = mf_ultralight_calc_auth_count(&emulator->data);
                     if(scaled_authlim != 0 && emulator->data.curr_authlim >= scaled_authlim) {
                         if(emulator->data.curr_authlim != UINT16_MAX) {
diff --git a/lib/nfc/protocols/mifare_ultralight.h b/lib/nfc/protocols/mifare_ultralight.h
index 9642824f7..957d5f9d5 100644
--- a/lib/nfc/protocols/mifare_ultralight.h
+++ b/lib/nfc/protocols/mifare_ultralight.h
@@ -185,6 +185,8 @@ typedef struct {
     bool sector_select_cmd_started;
     bool ntag_i2c_plus_sector3_lockout;
     bool read_counter_incremented;
+    bool auth_attempted;
+    MfUltralightAuth auth_attempt;
 } MfUltralightEmulator;
 
 void mf_ul_reset(MfUltralightData* data);