From: pwpiwi <pwpiwi@users.noreply.github.com>
Date: Mon, 15 Jan 2018 14:29:14 +0000 (+0100)
Subject: Revert changes in hardnested nonces collection. Sacrifice some speed in favor of... 
X-Git-Tag: v3.1.0~87
X-Git-Url: https://git.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/commitdiff_plain/d1f9ec06aec73db05a48df42fc1eb51a399754ba?hp=--cc

Revert changes in hardnested nonces collection. Sacrifice some speed in favor of stability for some card types (#547)
---

d1f9ec06aec73db05a48df42fc1eb51a399754ba
diff --git a/armsrc/mifarecmd.c b/armsrc/mifarecmd.c
index fcfd7e8f..3854b589 100644
--- a/armsrc/mifarecmd.c
+++ b/armsrc/mifarecmd.c
@@ -20,6 +20,9 @@
 #include "parity.h"
 #include "crc.h"
 
+#define HARDNESTED_AUTHENTICATION_TIMEOUT 848			// card times out 1ms after wrong authentication (according to NXP documentation)
+#define HARDNESTED_PRE_AUTHENTICATION_LEADTIME 400		// some (non standard) cards need a pause after select before they are ready for first authentication 
+
 // the block number for the ISO14443-4 PCB
 static uint8_t pcb_blocknum = 0;
 // Deselect card by sending a s-block. the crc is precalced for speed
@@ -677,7 +680,7 @@ void MifareAcquireEncryptedNonces(uint32_t arg0, uint32_t arg1, uint32_t flags,
 		}
 
 		if (slow) {
-			timeout = GetCountSspClk() + PRE_AUTHENTICATION_LEADTIME;
+			timeout = GetCountSspClk() + HARDNESTED_PRE_AUTHENTICATION_LEADTIME;
 			while(GetCountSspClk() < timeout);
 		}
 
@@ -694,10 +697,12 @@ void MifareAcquireEncryptedNonces(uint32_t arg0, uint32_t arg1, uint32_t flags,
 			continue;
 		}
 
-		// send a dummy response in order to trigger the cards authentication failure timeout
-		uint8_t dummy_answer[8] = {0};
-		ReaderTransmit(dummy_answer, 8, NULL);
+		// send an incomplete dummy response in order to trigger the card's authentication failure timeout
+		uint8_t dummy_answer[1] = {0};
+		ReaderTransmit(dummy_answer, 1, NULL);
 
+		timeout = GetCountSspClk() + HARDNESTED_AUTHENTICATION_TIMEOUT;
+		
 		num_nonces++;
 		if (num_nonces % 2) {
 			memcpy(buf+i, receivedAnswer, 4);
@@ -709,6 +714,9 @@ void MifareAcquireEncryptedNonces(uint32_t arg0, uint32_t arg1, uint32_t flags,
 			i += 9;
 		}
 
+		// wait for the card to become ready again
+		while(GetCountSspClk() < timeout);
+
 	}
 
 	LED_C_OFF();
diff --git a/armsrc/mifareutil.h b/armsrc/mifareutil.h
index c34dc8f4..b2912895 100644
--- a/armsrc/mifareutil.h
+++ b/armsrc/mifareutil.h
@@ -24,8 +24,6 @@
 #define CRYPT_REQUEST 2
 #define AUTH_FIRST    0	
 #define AUTH_NESTED   2
-#define AUTHENTICATION_TIMEOUT 848			// card times out 1ms after wrong authentication (according to NXP documentation)
-#define PRE_AUTHENTICATION_LEADTIME 400		// some (non standard) cards need a pause after select before they are ready for first authentication
 
 // mifare 4bit card answers
 #define CARD_ACK      0x0A  // 1010 - ACK