From 671ff89fcba1a1e46b1cde10d77a07fec13a4093 Mon Sep 17 00:00:00 2001
From: marshmellow42 <marshmellowrf@gmail.com>
Date: Tue, 29 Nov 2016 14:59:14 -0500
Subject: [PATCH] fix iclass write

thanks to prof_abrasive && go_tus
---
 armsrc/iclass.c | 28 ++++++++++++++++++----------
 1 file changed, 18 insertions(+), 10 deletions(-)

diff --git a/armsrc/iclass.c b/armsrc/iclass.c
index f99d0eca..eb5a5a79 100644
--- a/armsrc/iclass.c
+++ b/armsrc/iclass.c
@@ -1473,7 +1473,7 @@ void CodeIClassCommand(const uint8_t * cmd, int len)
     for(j = 0; j < 4; j++) {
       for(k = 0; k < 4; k++) {
 			if(k == (b & 3)) {
-				ToSend[++ToSendMax] = 0x0f;
+				ToSend[++ToSendMax] = 0xf0;
 			}
 			else {
 				ToSend[++ToSendMax] = 0x00;
@@ -1580,8 +1580,8 @@ void setupIclassReader()
 {
     FpgaDownloadAndGo(FPGA_BITSTREAM_HF);
     // Reset trace buffer
-	set_tracing(TRUE);
-	clear_trace();
+	  set_tracing(TRUE);
+	  clear_trace();
 
     // Setup SSC
     FpgaSetupSsc();
@@ -1671,7 +1671,7 @@ uint8_t handshakeIclassTag_ext(uint8_t *card_data, bool use_credit_key)
 
 	return read_status;
 }
-uint8_t handshakeIclassTag(uint8_t *card_data){
+uint8_t handshakeIclassTag(uint8_t *card_data) {
 	return handshakeIclassTag_ext(card_data, false);
 }
 
@@ -1983,18 +1983,26 @@ void iClass_Dump(uint8_t blockno, uint8_t numblks) {
 }
 
 bool iClass_WriteBlock_ext(uint8_t blockNo, uint8_t *data) {
-	uint8_t write[] = { ICLASS_CMD_UPDATE, blockNo, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
+	uint8_t write[] = { ICLASS_CMD_UPDATE, blockNo, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
 	//uint8_t readblockdata[10];
 	//write[1] = blockNo;
 	memcpy(write+2, data, 12); // data + mac
+	char *wrCmd = (char *)(write+1); 
+	uint16_t wrCrc = iclass_crc16(wrCmd, 13);
+	write[14] = wrCrc >> 8;
+	write[15] = wrCrc & 0xff;
 	uint8_t resp[] = {0,0,0,0,0,0,0,0,0,0};
-	bool isOK;
+	bool isOK = false;
+
 	isOK = sendCmdGetResponseWithRetries(write,sizeof(write),resp,sizeof(resp),10);
-	if (isOK) {
+	if (isOK) { //if reader responded correctly
 		//Dbprintf("WriteResp: %02X%02X%02X%02X%02X%02X%02X%02X%02X%02X",resp[0],resp[1],resp[2],resp[3],resp[4],resp[5],resp[6],resp[7],resp[8],resp[9]);
-		if (memcmp(write+2,resp,8)) {
-			//error try again
-			isOK = sendCmdGetResponseWithRetries(write,sizeof(write),resp,sizeof(resp),10);
+		if (memcmp(write+2,resp,8)) {  //if response is not equal to write values
+			if (blockNo != 3 && blockNo != 4) { //if not programming key areas (note key blocks don't get programmed with actual key data it is xor data)
+				//error try again
+				isOK = sendCmdGetResponseWithRetries(write,sizeof(write),resp,sizeof(resp),10);
+			} 
+			
 		}
 	}
 	return isOK;
-- 
2.39.2