From: iceman1001 Date: Wed, 15 Feb 2017 15:58:29 +0000 (+0100) Subject: CHG: `lf em` - @marshmellow42 's latest changes X-Git-Url: http://cvs.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/commitdiff_plain/f9f5f4500024230410171226f036c596d73b1bbc CHG: `lf em` - @marshmellow42 's latest changes --- diff --git a/client/cmdlfem4x.c b/client/cmdlfem4x.c index 636d2596..2cc03430 100644 --- a/client/cmdlfem4x.c +++ b/client/cmdlfem4x.c @@ -500,7 +500,7 @@ int CmdEM4x50Read(const char *Cmd) { } int usage_lf_em_read(void) { - PrintAndLog("Read EM4x50. Tag must be on antenna. "); + PrintAndLog("Read EM4x05/EM4x69. Tag must be on antenna. "); PrintAndLog(""); PrintAndLog("Usage: lf em readword [h]
"); PrintAndLog("Options:"); @@ -512,6 +512,125 @@ int usage_lf_em_read(void) { PrintAndLog(" lf em readword 1 11223344"); return 0; } + +//search for given preamble in given BitStream and return success=1 or fail=0 and startIndex +uint8_t EMpreambleSearch(uint8_t *BitStream, uint8_t *preamble, size_t pLen, size_t size, size_t *startIdx) +{ + // Sanity check. If preamble length is bigger than bitstream length. + if ( size <= pLen ) return 0; + // em only sends preamble once, so look for it once in the first x bits + uint8_t foundCnt = 0; + for (int idx = 0; idx < size - pLen; idx++){ + if (memcmp(BitStream+idx, preamble, pLen) == 0){ + //first index found + foundCnt++; + if (foundCnt == 1) { + *startIdx = idx; + return 1; + } + } + } + return 0; +} + +int demodEM4x05resp(uint8_t bitsNeeded) { + int ans = 0; + bool demodFound = false; + DemodBufferLen = 0x00; + // skip first two 0 bits as they might have been missed in the demod + uint8_t preamble[6] = {0,0,1,0,1,0}; + + // test for FSK wave (easiest to 99% ID) + if (GetFskClock("", FALSE, FALSE)) { + //valid fsk clocks found + ans = FSKrawDemod("0 0", false); + if (!ans) { + if (g_debugMode) PrintAndLog("DEBUG: Error - EM4305: FSK Demod failed"); + //return -1; + } else { + // set size to 10 to only test first 4 positions for the preamble + size_t size = (10 > DemodBufferLen) ? DemodBufferLen : 10; + size_t startIdx = 0; + + if (g_debugMode) PrintAndLog("ANS: %d | %u | %u", ans, startIdx, size); + + uint8_t errChk = !EMpreambleSearch(DemodBuffer, preamble, sizeof(preamble), size, &startIdx); + if ( errChk == 0) { + if (g_debugMode) PrintAndLog("DEBUG: Error - EM4305 preamble not found :: %d", startIdx); + //return -1; + } else { + //can't test size because the preamble doesn't repeat :( + //meaning chances of false positives are high. + demodFound = true; + } + } + } + + ans = GetPskClock("", FALSE, FALSE); + if (ans>0) { + PrintAndLog("PSK response possibly found, run `data rawd p1` to attempt to demod"); + } + + if (!demodFound) { + DemodBufferLen = 0x00; + //try biphase + ans = ASKbiphaseDemod("0 0 1", FALSE); + if (!ans) { + if (g_debugMode) PrintAndLog("DEBUG: Error - EM4305: ASK/biphase Demod failed"); + //return -1; + } else { + // set size to 10 to only test first 4 positions for the preamble + size_t size = (10 > DemodBufferLen) ? DemodBufferLen : 10; + size_t startIdx = 0; + + if (g_debugMode) PrintAndLog("ANS: %d | %u | %u", ans, startIdx, size); + + uint8_t errChk = !EMpreambleSearch(DemodBuffer, preamble, sizeof(preamble), size, &startIdx); + if ( errChk == 0) { + if (g_debugMode) PrintAndLog("DEBUG: Error - EM4305 preamble not found :: %d", startIdx); + //return -1; + } else { + //can't test size because the preamble doesn't repeat :( + //meaning chances of false positives are high. + demodFound = true; + } + } + } + + if (!demodFound) { + DemodBufferLen = 0x00; + // try manchester - NOTE: ST only applies to T55x7 tags. + ans = ASKDemod_ext("0,0,1", false, false, 1, false); + if (!ans) { + if (g_debugMode) PrintAndLog("DEBUG: Error - EM4305: ASK/Manchester Demod failed"); + //return -1; + } else { + // set size to 10 to only test first 4 positions for the preamble + size_t size = (10 > DemodBufferLen) ? DemodBufferLen : 10; + size_t startIdx = 0; + + if (g_debugMode) PrintAndLog("ANS: %d | %u | %u", ans, startIdx, size); + + uint8_t errChk = !EMpreambleSearch(DemodBuffer, preamble, sizeof(preamble), size, &startIdx); + if ( errChk == 0) { + if (g_debugMode) PrintAndLog("DEBUG: Error - EM4305 preamble not found :: %d", startIdx); + //return -1; + } else { + //can't test size because the preamble doesn't repeat :( + //meaning chances of false positives are high. + demodFound = true; + } + } + } + + if (demodFound && bitsNeeded < DemodBufferLen) { + setDemodBuf(DemodBuffer + ans + sizeof(preamble), bitsNeeded, 0); + CmdPrintDemodBuff("x"); + return 1; + } + return -1; +} + int CmdReadWord(const char *Cmd) { int addr, pwd; bool usePwd = false; @@ -548,44 +667,20 @@ int CmdReadWord(const char *Cmd) { return -1; } setGraphBuf(got, sizeof(got)); - - - int ans = 0; - //bool ST = true; - DemodBufferLen = 0x00; - - //ans = ASKDemod_ext("0 0 1", FALSE, FALSE, 1, &ST); - ans = ASKbiphaseDemod("0 0 1", FALSE); - if (!ans) { - if (g_debugMode) PrintAndLog("DEBUG: Error - EM4305: ASK/Manchester Demod failed"); - return -1; - } - - size_t startIdx = 0, size = DemodBufferLen; - - PrintAndLog("ANS: %d | %u | %u", ans, startIdx, size); - - - uint8_t preamble[8] = {0,0,0,0,1,0,1,0}; - uint8_t errChk = !preambleSearch(DemodBuffer, preamble, sizeof(preamble), &size, &startIdx); - if ( errChk == 0) { - if (g_debugMode) PrintAndLog("DEBUG: Error - EM4305 preamble not found :: %d", startIdx); - return -1; - } - - // sanity check. - if (size != 32) { - if (g_debugMode) PrintAndLog("DEBUG: Error - EM4305 incorrect data length found, %u", size ); + int testLen = (GraphTraceLen < 1000) ? GraphTraceLen : 1000; + if (graphJustNoise(GraphBuffer, testLen)) { + PrintAndLog("no tag not found"); return -1; } - //setDemodBuf(BitStream, 32, preambleIndex); + //need 32 bits for read word + demodEM4x05resp(32); return 1; } int usage_lf_em_write(void) { - PrintAndLog("Write EM4x50. Tag must be on antenna. "); + PrintAndLog("Write EM4x05/EM4x69. Tag must be on antenna. "); PrintAndLog(""); PrintAndLog("Usage: lf em writeword [h]
"); PrintAndLog("Options:"); @@ -654,7 +749,6 @@ int CmdWriteWord(const char *Cmd) { if (g_debugMode) PrintAndLog("DEBUG: Error - EM4305: ASK/Manchester Demod failed"); return -3; } - PrintAndLog("ANS: %d", ans); //todo: check response for 00001010 then write data for write confirmation! size_t startIdx = 0, size = DemodBufferLen;