From afcd2ed6cd2c6356f242c94a023b26208afe76bd Mon Sep 17 00:00:00 2001
From: "Aaron Tulino (Aaronjamt)" <git@aaronjamt.com>
Date: Wed, 18 Mar 2026 13:05:34 -0700
Subject: [PATCH] [hf 14a sim] Preliminary MFP_WRITEPERSO sim support Very
 early WIP, just logs address and value.

---
 armsrc/iso14443a.c | 43 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 43 insertions(+)

diff --git a/armsrc/iso14443a.c b/armsrc/iso14443a.c
index 1bddbb130..0cf192f88 100644
--- a/armsrc/iso14443a.c
+++ b/armsrc/iso14443a.c
@@ -2270,6 +2270,49 @@ void SimulateIso14443aTagEx(uint8_t tagType, uint16_t flags, uint8_t *useruid, u
             EmSendCmd(cmd, sizeof(cmd));
             p_response = NULL;
 
+        } else if (receivedCmd[0] == MFP_WRITEPERSO && len == 21 && (tagType == 15)) {
+            // cmd + 2 bytes block + value + 2 bytes crc
+            if (CheckCrc14A(receivedCmd, len)) {
+                uint16_t page = receivedCmd[1] | (receivedCmd[2] << 8);
+                if (page > 0x9005 || page < 0x9000) {
+                    // send NACK 0x0 == invalid argument
+                    EmSend4bit(CARD_NACK_IV);
+                } else {
+                    // send ACK
+                    EmSend4bit(CARD_ACK);
+
+                    Dbprintf("MFP Perso Key | %04X | %02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X",
+                        page,
+                        receivedCmd[3],
+                        receivedCmd[4],
+                        receivedCmd[5],
+                        receivedCmd[6],
+                        receivedCmd[7],
+                        receivedCmd[8],
+                        receivedCmd[9],
+                        receivedCmd[10],
+                        receivedCmd[11],
+                        receivedCmd[12],
+                        receivedCmd[13],
+                        receivedCmd[14],
+                        receivedCmd[15],
+                        receivedCmd[16],
+                        receivedCmd[17],
+                        receivedCmd[18]
+                    );
+
+                    numReads++;  // Increment number of times reader requested a block
+
+                    if (exitAfterNReads > 0 && numReads == exitAfterNReads) {
+                        finished = true;
+                    }
+                }
+            } else {
+                // send NACK 0x1 == crc/parity error
+                EmSend4bit(CARD_NACK_PA);
+            }
+            p_response = NULL;
+
         } else {
 
             // clear old dynamic responses