cvs.zerfleddert.de Git - proxmark3-svn/blob - client/cmdlfsecurakey.c

   1 //-----------------------------------------------------------------------------
   2 //
   3 // This code is licensed to you under the terms of the GNU GPL, version 2 or,
   4 // at your option, any later version. See the LICENSE.txt file for the text of
   5 // the license.
   6 //-----------------------------------------------------------------------------
   7 // Low frequency Securakey tag commands
   8 // ASK/Manchester, RF/40, 96 bits long (unknown cs)
   9 //-----------------------------------------------------------------------------
  10 #include "cmdlfsecurakey.h"
  11 #include <string.h>
  12 #include <inttypes.h>
  13 #include <math.h>
  14 #include "proxmark3.h"
  15 #include "ui.h"
  16 #include "util.h"
  17 #include "graph.h"
  18 #include "cmdparser.h"
  19 #include "cmddata.h"
  20 #include "cmdmain.h"
  21 #include "cmdlf.h"
  22 #include "protocols.h"  // for T55xx config register definitions
  23 #include "lfdemod.h"    // preamble test
  24 #include "parity.h"     // for wiegand parity test
  25
  26 static int CmdHelp(const char *Cmd);
  27
  28 // by marshmellow
  29 // find Securakey preamble in already demoded data
  30 int SecurakeyFind(uint8_t *dest, size_t *size) {
  31         if (*size < 96) return -1; //make sure buffer has data
  32         size_t startIdx = 0;
  33         uint8_t preamble[] = {0,1,1,1,1,1,1,1,1,1,0,0,1};
  34         if (!preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx))
  35                 return -2; //preamble not found
  36         if (*size != 96) return -3; //wrong demoded size
  37         //return start position
  38         return (int)startIdx;
  39 }
  40
  41 //see ASKDemod for what args are accepted
  42 int CmdSecurakeyDemod(const char *Cmd) {
  43
  44         //ASK / Manchester
  45         bool st = false;
  46         if (!ASKDemod_ext("40 0 0", false, false, 1, &st)) {
  47                 if (g_debugMode) PrintAndLog("DEBUG: Error - Securakey: ASK/Manchester Demod failed");
  48                 return 0;
  49         }
  50         if (st) return 0;
  51         size_t size = DemodBufferLen;
  52         int ans = SecurakeyFind(DemodBuffer, &size);
  53         if (ans < 0) {
  54                 if (g_debugMode) {
  55                         if (ans == -1)
  56                                 PrintAndLog("DEBUG: Error - Securakey: too few bits found");
  57                         else if (ans == -2)
  58                                 PrintAndLog("DEBUG: Error - Securakey: preamble not found");
  59                         else if (ans == -3)
  60                                 PrintAndLog("DEBUG: Error - Securakey: Size not correct: %d", size);
  61                         else
  62                                 PrintAndLog("DEBUG: Error - Securakey: ans: %d", ans);
  63                 }
  64                 return 0;
  65         }
  66         setDemodBuf(DemodBuffer, 96, ans);
  67         setClockGrid(g_DemodClock, g_DemodStartIdx + (ans*g_DemodClock));
  68
  69         //got a good demod
  70         uint32_t raw1 = bytebits_to_byte(DemodBuffer   , 32);
  71         uint32_t raw2 = bytebits_to_byte(DemodBuffer+32, 32);
  72         uint32_t raw3 = bytebits_to_byte(DemodBuffer+64, 32);
  73
  74         // 26 bit format
  75         // preamble     ??bitlen   reserved        EPx   xxxxxxxy   yyyyyyyy   yyyyyyyOP  CS?        CS2?
  76         // 0111111111 0 01011010 0 00000000 0 00000010 0 00110110 0 00111110 0 01100010 0 00001111 0 01100000 0 00000000 0 0000
  77
  78         // 32 bit format
  79         // preamble     ??bitlen   reserved  EPxxxxxxx   xxxxxxxy   yyyyyyyy   yyyyyyyOP  CS?        CS2?
  80         // 0111111111 0 01100000 0 00000000 0 10000100 0 11001010 0 01011011 0 01010110 0 00010110 0 11100000 0 00000000 0 0000
  81
  82         // x = FC?
  83         // y = card #
  84         // standard wiegand parities.
  85         // unknown checksum 11 bits? at the end
  86         uint8_t bits_no_spacer[85];
  87         memcpy(bits_no_spacer, DemodBuffer + 11, 85);
  88
  89         // remove marker bits (0's every 9th digit after preamble) (pType = 3 (always 0s))
  90         size = removeParity(bits_no_spacer, 0, 9, 3, 85);
  91         if ( size != 85-9 ) {
  92                 if (g_debugMode) PrintAndLog("DEBUG: Error removeParity: %d", size);
  93                 return 0;
  94         }
  95
  96         uint8_t bitLen = (uint8_t)bytebits_to_byte(bits_no_spacer+2, 6);
  97         uint32_t fc=0, lWiegand=0, rWiegand=0;
  98         if (bitLen > 40) { //securakey's max bitlen is 40 bits...
  99                 if (g_debugMode) PrintAndLog("DEBUG: Error bitLen too long: %u", bitLen);
 100                 return 0;
 101         }
 102         // get left 1/2 wiegand & right 1/2 wiegand (for parity test and wiegand print)
 103         lWiegand = bytebits_to_byte(bits_no_spacer + 48 - bitLen, bitLen/2);
 104         rWiegand = bytebits_to_byte(bits_no_spacer + 48 - bitLen + bitLen/2, bitLen/2);
 105         // get FC
 106         fc = bytebits_to_byte(bits_no_spacer+49-bitLen, bitLen-2-16);
 107
 108         // test bitLen
 109         if (bitLen != 26 && bitLen != 32)
 110                 PrintAndLog("***unknown securakey bitLen - share with forum***");
 111
 112         uint32_t cardid = bytebits_to_byte(bits_no_spacer+8+23, 16);
 113         // test parities - evenparity32 looks to add an even parity returns 0 if already even...
 114         bool parity = !evenparity32(lWiegand) && !oddparity32(rWiegand);
 115
 116         PrintAndLog("Securakey Tag Found--BitLen: %u, Card ID: %u, FC: 0x%X, Raw: %08X%08X%08X", bitLen, cardid, fc, raw1 ,raw2, raw3);
 117         if (bitLen <= 32)
 118                 PrintAndLog("Wiegand: %08X, Parity: %s", (lWiegand<<(bitLen/2)) | rWiegand, parity ? "Passed" : "Failed");
 119         PrintAndLog("\nHow the FC translates to printed FC is unknown");
 120         PrintAndLog("How the checksum is calculated is unknown");
 121         PrintAndLog("Help the community identify this format further\n by sharing your tag on the pm3 forum or with forum members");
 122         return 1;
 123 }
 124
 125 int CmdSecurakeyRead(const char *Cmd) {
 126         lf_read(true, 8000);
 127         return CmdSecurakeyDemod(Cmd);
 128 }
 129
 130 static command_t CommandTable[] = {
 131         {"help",  CmdHelp,          1, "This help"},
 132         {"demod", CmdSecurakeyDemod,1, "Attempt to read and extract tag data from the GraphBuffer"},
 133         {"read",  CmdSecurakeyRead, 0, "Attempt to read and extract tag data from the antenna"},
 134     {NULL, NULL, 0, NULL}
 135 };
 136
 137 int CmdLFSecurakey(const char *Cmd) {
 138         clearCommandBuffer();
 139         CmdsParse(CommandTable, Cmd);
 140         return 0;
 141 }
 142
 143 int CmdHelp(const char *Cmd) {
 144         CmdsHelp(CommandTable);
 145         return 0;
 146 }