From 4adf6633004ac6efdbd42715e1d7131605d028cc Mon Sep 17 00:00:00 2001
From: Lucifer Voeltner <lucifervoeltner03@gmail.com>
Date: Sun, 1 Dec 2024 16:27:35 +0700
Subject: [PATCH] Fix Gen 3 APDU block 0 SAK not being written correctly

---
 armsrc/mifarecmd.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/armsrc/mifarecmd.c b/armsrc/mifarecmd.c
index 659c5eec00..2eed2ca5c6 100644
--- a/armsrc/mifarecmd.c
+++ b/armsrc/mifarecmd.c
@@ -3482,7 +3482,8 @@ void MifareGen3Blk(uint8_t block_len, uint8_t *block) {
             retval = PM3_ESOFT;
             goto OUT;
         }
-        cmd[ofs++] = card_info->sak;
+        cmd[ofs] = block_len < card_info->uidlen ? card_info->sak : cmd[ofs];
+        ofs++;
         cmd[ofs++] = card_info->atqa[0];
         cmd[ofs++] = card_info->atqa[1];
         AddCrc14A(cmd, sizeof(block_cmd) + MIFARE_BLOCK_SIZE);