armsrc/mifaresniff.c

   1 //-----------------------------------------------------------------------------
   2 // Merlok - 2012
   3 //
   4 // This code is licensed to you under the terms of the GNU GPL, version 2 or,
   5 // at your option, any later version. See the LICENSE.txt file for the text of
   6 // the license.
   7 //-----------------------------------------------------------------------------
   8 // Routines to support mifare classic sniffer.
   9 //-----------------------------------------------------------------------------
  10
  11 #include "mifaresniff.h"
  12 #include "apps.h"
  13
  14 static int sniffState = SNF_INIT;
  15 static uint8_t sniffUIDType;
  16 static uint8_t sniffUID[8] = {0x00};
  17 static uint8_t sniffATQA[2] = {0x00};
  18 static uint8_t sniffSAK;
  19 static uint8_t sniffBuf[16] = {0x00};
  20 static uint32_t timerData = 0;
  21
  22
  23 bool MfSniffInit(void){
  24         memset(sniffUID, 0x00, 8);
  25         memset(sniffATQA, 0x00, 2);
  26         sniffSAK = 0;
  27         sniffUIDType = SNF_UID_4;
  28
  29         return FALSE;
  30 }
  31
  32 bool MfSniffEnd(void){
  33         LED_B_ON();
  34         cmd_send(CMD_ACK,0,0,0,0,0);
  35         LED_B_OFF();
  36
  37         return FALSE;
  38 }
  39
  40 bool RAMFUNC MfSniffLogic(const uint8_t *data, uint16_t len, uint8_t *parity, uint16_t bitCnt, bool reader) {
  41
  42         if (reader && (len == 1) && (bitCnt == 7)) {            // reset on 7-Bit commands from reader
  43                 sniffState = SNF_INIT;
  44         }
  45
  46         switch (sniffState) {
  47                 case SNF_INIT:{
  48                         if ((len == 1) && (reader) && (bitCnt == 7) ) {  // REQA or WUPA from reader
  49                                 sniffUIDType = SNF_UID_4;
  50                                 memset(sniffUID, 0x00, 8);
  51                                 memset(sniffATQA, 0x00, 2);
  52                                 sniffSAK = 0;
  53                                 sniffState = SNF_WUPREQ;
  54                         }
  55                         break;
  56                 }
  57                 case SNF_WUPREQ:{
  58                         if ((!reader) && (len == 2)) {          // ATQA from tag
  59                                 memcpy(sniffATQA, data, 2);
  60                                 sniffState = SNF_ATQA;
  61                         }
  62                         break;
  63                 }
  64                 case SNF_ATQA:{
  65                         if ((reader) && (len == 2) && (data[0] == 0x93) && (data[1] == 0x20)) { // Select ALL from reader
  66                                 sniffState = SNF_ANTICOL1;
  67                         }
  68                         break;
  69                 }
  70                 case SNF_ANTICOL1:{
  71                         if ((!reader) && (len == 5) && ((data[0] ^ data[1] ^ data[2] ^ data[3]) == data[4])) {  // UID from tag (CL1)
  72                                 memcpy(sniffUID + 3, data, 4);
  73                                 sniffState = SNF_UID1;
  74                         }
  75                         break;
  76                 }
  77                 case SNF_UID1:{
  78                         if ((reader) && (len == 9) && (data[0] == 0x93) && (data[1] == 0x70) && (CheckCrc14443(CRC_14443_A, data, 9))) {   // Select 4 Byte UID from reader
  79                                 sniffState = SNF_SAK;
  80                         }
  81                         break;
  82                 }
  83                 case SNF_SAK:{
  84                         if ((!reader) && (len == 3) && (CheckCrc14443(CRC_14443_A, data, 3))) { // SAK from card?
  85                                 sniffSAK = data[0];
  86                                 if (sniffUID[3] == 0x88) {                      // CL2 UID part to be expected
  87                                         sniffState = SNF_ANTICOL2;
  88                                 } else {                                                        // select completed
  89                                         sniffState = SNF_CARD_IDLE;
  90                                 }
  91                         }
  92                         break;
  93                 }
  94                 case SNF_ANTICOL2:{
  95                         if ((!reader) && (len == 5) && ((data[0] ^ data[1] ^ data[2] ^ data[3]) == data[4])) { // CL2 UID
  96                                 memcpy(sniffUID, sniffUID+4, 3);
  97                                 memcpy(sniffUID+3, data, 4);
  98                                 sniffUIDType = SNF_UID_7;
  99                                 sniffState = SNF_UID2;
 100                         }
 101                         break;
 102                 }
 103                 case SNF_UID2:{
 104                         if ((reader) && (len == 9) && (data[0] == 0x95) && (data[1] == 0x70) && (CheckCrc14443(CRC_14443_A, data, 9))) {        // Select 2nd part of 7 Byte UID
 105                                 sniffState = SNF_SAK;
 106                         }
 107                         break;
 108                 }
 109                 case SNF_CARD_IDLE:{    // trace the card select sequence
 110                         sniffBuf[0] = 0xFF;
 111                         sniffBuf[1] = 0xFF;
 112                         memcpy(sniffBuf + 2, sniffUID, 7);
 113                         memcpy(sniffBuf + 9, sniffATQA, 2);
 114                         sniffBuf[11] = sniffSAK;
 115                         sniffBuf[12] = 0xFF;
 116                         sniffBuf[13] = 0xFF;
 117                         LogTrace(sniffBuf, 14, 0, 0, NULL, TRUE);
 118                 }       // intentionally no break;
 119                 case SNF_CARD_CMD:{
 120                         LogTrace(data, len, 0, 0, NULL, TRUE);
 121                         sniffState = SNF_CARD_RESP;
 122                         timerData = GetTickCount();
 123                         break;
 124                 }
 125                 case SNF_CARD_RESP:{
 126                         LogTrace(data, len, 0, 0, NULL, FALSE);
 127                         sniffState = SNF_CARD_CMD;
 128                         timerData = GetTickCount();
 129                         break;
 130                 }
 131
 132                 default:
 133                         sniffState = SNF_INIT;
 134                 break;
 135         }
 136
 137
 138         return FALSE;
 139 }
 140
 141 bool RAMFUNC MfSniffSend(uint16_t maxTimeoutMs) {
 142         if (traceLen && (GetTickCount() > timerData + maxTimeoutMs)) {
 143                 return intMfSniffSend();
 144         }
 145         return FALSE;
 146 }
 147
 148 // internal sending function. not a RAMFUNC.
 149 bool intMfSniffSend() {
 150
 151         int pckSize = 0;
 152         int pckLen = traceLen;
 153         int pckNum = 0;
 154         uint8_t *trace = BigBuf_get_addr();
 155
 156         FpgaDisableSscDma();
 157         while (pckLen > 0) {
 158                 pckSize = MIN(USB_CMD_DATA_SIZE, pckLen);
 159                 LED_B_ON();
 160                 cmd_send(CMD_ACK, 1, traceLen, pckSize, trace + traceLen - pckLen, pckSize);
 161                 LED_B_OFF();
 162
 163                 pckLen -= pckSize;
 164                 pckNum++;
 165         }
 166
 167         LED_B_ON();
 168         cmd_send(CMD_ACK,2,0,0,0,0);
 169         LED_B_OFF();
 170
 171         iso14a_clear_trace();
 172
 173         return TRUE;
 174 }