CHG: lf em - @marshmellow42 's latest changes

This commit is contained in:
iceman1001 2017-02-15 16:58:29 +01:00
parent c930078036
commit f9f5f45000

View file

@ -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] <address> <pwd>");
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");
int testLen = (GraphTraceLen < 1000) ? GraphTraceLen : 1000;
if (graphJustNoise(GraphBuffer, testLen)) {
PrintAndLog("no tag not found");
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 );
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] <address> <data> <pwd>");
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;