| 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 Honeywell NexWatch tag commands |
| 8 | // PSK1 RF/16, RF/2, 128 bits long (known) |
| 9 | //----------------------------------------------------------------------------- |
| 10 | #include <stdio.h> |
| 11 | #include <string.h> |
| 12 | #include <inttypes.h> |
| 13 | #include <stdbool.h> |
| 14 | #include "cmdlfnexwatch.h" |
| 15 | #include "proxmark3.h" |
| 16 | #include "ui.h" |
| 17 | #include "util.h" |
| 18 | #include "graph.h" |
| 19 | #include "cmdparser.h" |
| 20 | #include "cmddata.h" |
| 21 | #include "cmdlf.h" |
| 22 | #include "lfdemod.h" |
| 23 | |
| 24 | static int CmdHelp(const char *Cmd); |
| 25 | |
| 26 | int CmdPSKNexWatch(const char *Cmd) |
| 27 | { |
| 28 | if (!PSKDemod("", false)) return 0; |
| 29 | uint8_t preamble[28] = {0,0,0,0,0,1,0,1,0,1,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0}; |
| 30 | size_t startIdx = 0, size = DemodBufferLen; |
| 31 | bool invert = false; |
| 32 | if (!preambleSearch(DemodBuffer, preamble, sizeof(preamble), &size, &startIdx)){ |
| 33 | // if didn't find preamble try again inverting |
| 34 | if (!PSKDemod("1", false)) return 0; |
| 35 | size = DemodBufferLen; |
| 36 | if (!preambleSearch(DemodBuffer, preamble, sizeof(preamble), &size, &startIdx)) return 0; |
| 37 | invert = true; |
| 38 | } |
| 39 | if (size != 128) return 0; |
| 40 | setDemodBuf(DemodBuffer, size, startIdx+4); |
| 41 | setClockGrid(g_DemodClock, g_DemodStartIdx + ((startIdx+4)*g_DemodClock)); |
| 42 | startIdx = 8+32; // 8 = preamble, 32 = reserved bits (always 0) |
| 43 | //get ID |
| 44 | uint32_t ID = 0; |
| 45 | for (uint8_t wordIdx=0; wordIdx<4; wordIdx++){ |
| 46 | for (uint8_t idx=0; idx<8; idx++){ |
| 47 | ID = (ID << 1) | DemodBuffer[startIdx+wordIdx+(idx*4)]; |
| 48 | } |
| 49 | } |
| 50 | //parity check (TBD) |
| 51 | |
| 52 | //checksum check (TBD) |
| 53 | |
| 54 | //output |
| 55 | PrintAndLog("NexWatch ID: %d", ID); |
| 56 | if (invert){ |
| 57 | PrintAndLog("Had to Invert - probably NexKey"); |
| 58 | for (uint8_t idx=0; idx<size; idx++) |
| 59 | DemodBuffer[idx] ^= 1; |
| 60 | } |
| 61 | |
| 62 | CmdPrintDemodBuff("x"); |
| 63 | return 1; |
| 64 | } |
| 65 | |
| 66 | //by marshmellow |
| 67 | //see ASKDemod for what args are accepted |
| 68 | int CmdNexWatchRead(const char *Cmd) { |
| 69 | // read lf silently |
| 70 | lf_read(true, 10000); |
| 71 | // demod and output viking ID |
| 72 | return CmdPSKNexWatch(Cmd); |
| 73 | } |
| 74 | |
| 75 | static command_t CommandTable[] = { |
| 76 | {"help", CmdHelp, 1, "This help"}, |
| 77 | {"demod", CmdPSKNexWatch, 1, "Demodulate a NexWatch tag (nexkey, quadrakey) from the GraphBuffer"}, |
| 78 | {"read", CmdNexWatchRead, 0, "Attempt to Read and Extract tag data from the antenna"}, |
| 79 | {NULL, NULL, 0, NULL} |
| 80 | }; |
| 81 | |
| 82 | int CmdLFNexWatch(const char *Cmd) { |
| 83 | CmdsParse(CommandTable, Cmd); |
| 84 | return 0; |
| 85 | } |
| 86 | |
| 87 | int CmdHelp(const char *Cmd) { |
| 88 | CmdsHelp(CommandTable); |
| 89 | return 0; |
| 90 | } |