From 7314995a5a3979452d5a104dc243460dfa945ffd Mon Sep 17 00:00:00 2001
From: marshmellow42 <marshmellowrf@gmail.com>
Date: Wed, 22 Jun 2016 11:26:11 -0400
Subject: [PATCH] hf mf sim x reader attack add-ons

forgot to include the mfkey32 attack
---
 client/nonce2key/nonce2key.c | 42 ++++++++++++++++++++++++++++++++++++
 client/nonce2key/nonce2key.h |  1 +
 2 files changed, 43 insertions(+)

diff --git a/client/nonce2key/nonce2key.c b/client/nonce2key/nonce2key.c
index 70d874fe..9abc814b 100644
--- a/client/nonce2key/nonce2key.c
+++ b/client/nonce2key/nonce2key.c
@@ -149,3 +149,45 @@ int nonce2key(uint32_t uid, uint32_t nt, uint32_t nr, uint64_t par_info, uint64_
 	
 	return 1;
 }
+
+// 32 bit recover key from 2 nonces
+uint64_t mfkey32(uint32_t uid, uint32_t nt, uint32_t nr0_enc, uint32_t ar0_enc, uint32_t nr1_enc, uint32_t ar1_enc) {
+	struct Crypto1State *s,*t;
+	uint64_t key=0;     // recovered key
+	/*uint32_t uid;     // serial number
+	uint32_t nt;      // tag challenge
+	uint32_t nr0_enc; // first encrypted reader challenge
+	uint32_t ar0_enc; // first encrypted reader response
+	uint32_t nr1_enc; // second encrypted reader challenge
+	uint32_t ar1_enc; // second encrypted reader response
+ */
+	uint8_t found=0;
+	//uint32_t ks2;     // keystream used to encrypt reader response
+
+	// Generate lfsr succesors of the tag challenge
+	prng_successor(nt, 64);
+	prng_successor(nt, 96);
+
+	// Extract the keystream from the messages
+	//ks2 = ar0_enc ^ prng_successor(nt, 64);
+
+	s = lfsr_recovery32(ar0_enc ^ prng_successor(nt, 64), 0);
+
+	for(t = s; t->odd | t->even; ++t) {
+		lfsr_rollback_word(t, 0, 0);
+		lfsr_rollback_word(t, nr0_enc, 1);
+		lfsr_rollback_word(t, uid ^ nt, 0);
+		crypto1_get_lfsr(t, &key);
+		crypto1_word(t, uid ^ nt, 0);
+		crypto1_word(t, nr1_enc, 1);
+		if (ar1_enc == (crypto1_word(t, 0, 0) ^ prng_successor(nt, 64))) {
+			//printf("\nFound Key: [%012"llx"]\n\n",key);
+			found = 1;
+			break;
+		}
+	}
+	free(s);
+
+	if (found) return key;
+	return 0;
+}
diff --git a/client/nonce2key/nonce2key.h b/client/nonce2key/nonce2key.h
index e7d5f431..b00a85dc 100644
--- a/client/nonce2key/nonce2key.h
+++ b/client/nonce2key/nonce2key.h
@@ -19,5 +19,6 @@
 #include "common.h"
 
 int nonce2key(uint32_t uid, uint32_t nt, uint32_t nr, uint64_t par_info, uint64_t ks_info, uint64_t * key); 
+uint64_t mfkey32(uint32_t uid, uint32_t nt, uint32_t nr0_enc, uint32_t ar0_enc, uint32_t nr1_enc, uint32_t ar1_enc);
 
 #endif
-- 
2.39.5