From 184c5dcbdf50b5f5700ee5c7c2aa3fc70a5028b6 Mon Sep 17 00:00:00 2001
From: Robert Clausecker <fuzxxl@gmail.com>
Date: Tue, 25 Feb 2014 01:31:37 +0100
Subject: [PATCH] Return EACCES when authentication to an ultralight tag fails

---
 libfreefare/mifare_ultralight.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/libfreefare/mifare_ultralight.c b/libfreefare/mifare_ultralight.c
index b442aa4..f94adcd 100644
--- a/libfreefare/mifare_ultralight.c
+++ b/libfreefare/mifare_ultralight.c
@@ -301,6 +301,7 @@ mifare_ultralightc_authenticate (MifareTag tag, const MifareDESFireKey key)
     rol (PCD_RndA_s, 8);
 
     if (0 != memcmp (PCD_RndA_s, PICC_RndA_s, 8)) {
+	errno = EACCES;
 	return -1;
     }
     // XXX Should we store the state "authenticated" in the tag struct??