From 7d1495940f1a892b1cb0b5bf5bd7d5914d083aa0 Mon Sep 17 00:00:00 2001
From: Romuald Conty <romuald@libnfc.org>
Date: Wed, 6 Jan 2010 23:42:06 +0000
Subject: [PATCH] add an accessor to UID contained in MifareClassicTag

---
 freefare.h       |  2 ++
 mifare_classic.c | 18 ++++++++++++++++++
 2 files changed, 20 insertions(+)

diff --git a/freefare.h b/freefare.h
index da57424..cb4e72b 100644
--- a/freefare.h
+++ b/freefare.h
@@ -61,6 +61,8 @@ int 		 mifare_classic_get_trailer_block_permission (MifareClassicTag tag, const
 int		 mifare_classic_get_data_block_permission (MifareClassicTag tag, const MifareClassicBlockNumber block, const unsigned char permission, const MifareClassicKeyType key_type);
 
 int		 mifare_classic_format_sector (MifareClassicTag tag, const MifareSectorNumber sector);
+char*		 mifare_classic_get_uid(MifareClassicTag tag);
+
 void		 mifare_classic_trailer_block (MifareClassicBlock *block, const MifareClassicKey key_a, const uint8_t ab_0, const uint8_t ab_1, const uint8_t ab_2, const uint8_t ab_tb, const uint8_t gpb, const MifareClassicKey key_b);
 
 /* MIFARE Classic Access Bits */
diff --git a/mifare_classic.c b/mifare_classic.c
index eea90ce..af7630b 100644
--- a/mifare_classic.c
+++ b/mifare_classic.c
@@ -693,6 +693,24 @@ mifare_classic_format_sector (MifareClassicTag tag, const MifareSectorNumber sec
     return 0;
 }
 
+/*
+ * UID accessor
+ */
+char*
+mifare_classic_get_uid(MifareClassicTag tag)
+{
+  char* uid = malloc((4 * 2) + 1);
+  for( uint8_t i = 0; i < 4; i++) {
+    unsigned char msb = (tag->info.abtUid[i] | 0xf0) >> 4;
+    unsigned char lsb = (tag->info.abtUid[i] | 0x0f);
+
+    uid[i] = msb < 9 ? msb + '0' : msb + 'a';
+    uid[i+1] = lsb < 9 ? lsb + '0' : lsb + 'a';
+  }
+  uid[8] = '\0';
+  return uid;
+}
+
 /*
  * Generates a MIFARE trailer block.
  */