| | 1 | //----------------------------------------------------------------------------- |
| | 2 | // Copyright (C) 2016 iceman |
| | 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 | // Analyse bytes commands |
| | 9 | //----------------------------------------------------------------------------- |
| | 10 | #include "cmdanalyse.h" |
| | 11 | |
| | 12 | static int CmdHelp(const char *Cmd); |
| | 13 | |
| | 14 | int usage_analyse_lcr(void) { |
| | 15 | PrintAndLog("Specifying the bytes of a UID with a known LRC will find the last byte value"); |
| | 16 | PrintAndLog("needed to generate that LRC with a rolling XOR. All bytes should be specified in HEX."); |
| | 17 | PrintAndLog(""); |
| | 18 | PrintAndLog("Usage: analyse lcr [h] <bytes>"); |
| | 19 | PrintAndLog("Options:"); |
| | 20 | PrintAndLog(" h This help"); |
| | 21 | PrintAndLog(" <bytes> bytes to calc missing XOR in a LCR"); |
| | 22 | PrintAndLog(""); |
| | 23 | PrintAndLog("Samples:"); |
| | 24 | PrintAndLog(" analyse lcr 04008064BA"); |
| | 25 | PrintAndLog("expected output: Target (BA) requires final LRC XOR byte value: 5A"); |
| | 26 | return 0; |
| | 27 | } |
| | 28 | static uint8_t calculateLRC( uint8_t* bytes, uint8_t len) { |
| | 29 | uint8_t LRC = 0; |
| | 30 | for (uint8_t i = 0; i < len; i++) |
| | 31 | LRC ^= bytes[i]; |
| | 32 | return LRC; |
| | 33 | } |
| | 34 | |
| | 35 | int CmdAnalyseLCR(const char *Cmd) { |
| | 36 | uint8_t data[50]; |
| | 37 | char cmdp = param_getchar(Cmd, 0); |
| | 38 | if (strlen(Cmd) == 0|| cmdp == 'h' || cmdp == 'H') return usage_analyse_lcr(); |
| | 39 | |
| | 40 | int len = 0; |
| | 41 | param_gethex_ex(Cmd, 0, data, &len); |
| | 42 | if ( len%2 ) return usage_analyse_lcr(); |
| | 43 | len >>= 1; |
| | 44 | uint8_t finalXor = calculateLRC(data, len); |
| | 45 | PrintAndLog("Target [%02X] requires final LRC XOR byte value: 0x%02X",data[len-1] ,finalXor); |
| | 46 | return 0; |
| | 47 | } |
| | 48 | |
| | 49 | int CmdAnalyseDates(const char *Cmd){ |
| | 50 | // look for datestamps in a given array of bytes |
| | 51 | PrintAndLog("To be implemented. If you feel to contribute!"); |
| | 52 | return 0; |
| | 53 | } |
| | 54 | |
| | 55 | static command_t CommandTable[] = { |
| | 56 | {"help", CmdHelp, 1, "This help"}, |
| | 57 | {"lcr", CmdAnalyseLCR, 0, "Generate final byte for XOR LRC"}, |
| | 58 | {"dates", CmdAnalyseDates, 0, "Look for datestamps in a given array of bytes"}, |
| | 59 | {NULL, NULL, 0, NULL} |
| | 60 | }; |
| | 61 | |
| | 62 | int CmdAnalyse(const char *Cmd) { |
| | 63 | clearCommandBuffer(); |
| | 64 | CmdsParse(CommandTable, Cmd); |
| | 65 | return 0; |
| | 66 | } |
| | 67 | |
| | 68 | int CmdHelp(const char *Cmd) { |
| | 69 | CmdsHelp(CommandTable); |
| | 70 | return 0; |
| | 71 | } |
projects / proxmark3-svn / blame_incremental