github/RRG-Proxmark3
1
0
Fork 0
mirror of https://github.com/RfidResearchGroup/proxmark3.git synced 2025-08-21 05:43:48 -07:00
Code Issues Projects Releases Packages Wiki Activity Actions 4

CHG: @marshmellow42 's em4x50 changes

Browse source 
ADD: 'analys chksum' - added a BSD styled 4 and 8 bit shift checksum
This commit is contained in:
iceman1001 2017-02-16 09:53:47 +01:00
commit 62dc7d4a6f
2 changed files with 101 additions and 50 deletions
Download patch file Download diff file Expand all files Collapse all files

76
client/cmdlfem4x.c
View file

@ -533,6 +533,9 @@ uint8_t EMpreambleSearch(uint8_t *BitStream, uint8_t *preamble, size_t pLen, siz
return 0;
}
// FSK, PSK, ASK/MANCHESTER, ASK/BIPHASE, ASK/DIPHASE
// should cover 90% of known used configs
// the rest will need to be manually demoded for now...
int demodEM4x05resp(uint8_t bitsNeeded) {
int ans = 0;
bool demodFound = false;
@ -546,7 +549,6 @@ int demodEM4x05resp(uint8_t bitsNeeded) {
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;
@ -557,7 +559,6 @@ int demodEM4x05resp(uint8_t bitsNeeded) {
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.
@ -565,11 +566,38 @@ int demodEM4x05resp(uint8_t bitsNeeded) {
}
}
}
// PSK clocks should be easy to detect ( but difficult to demod a non-repeating pattern... )
if (!demodFound) {
ans = GetPskClock("", FALSE, FALSE);
if (ans>0) {
PrintAndLog("PSK response possibly found, run `data rawd p1` to attempt to demod");
}
}
// more common than biphase
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");
} 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);
} else {
//can't test size because the preamble doesn't repeat :(
//meaning chances of false positives are high.
demodFound = true;
}
}
}
if (!demodFound) {
DemodBufferLen = 0x00;
@ -599,11 +627,10 @@ int demodEM4x05resp(uint8_t bitsNeeded) {
if (!demodFound) {
DemodBufferLen = 0x00;
// try manchester - NOTE: ST only applies to T55x7 tags.
ans = ASKDemod_ext("0,0,1", false, false, 1, false);
//try diphase (differential biphase or inverted)
ans = ASKbiphaseDemod("0 1 1", FALSE);
if (!ans) {
if (g_debugMode) PrintAndLog("DEBUG: Error - EM4305: ASK/Manchester Demod failed");
//return -1;
if (g_debugMode) PrintAndLog("DEBUG: Error - EM4305: ASK/biphase Demod failed");
} else {
// set size to 10 to only test first 4 positions for the preamble
size_t size = (10 > DemodBufferLen) ? DemodBufferLen : 10;
@ -614,7 +641,6 @@ int demodEM4x05resp(uint8_t bitsNeeded) {
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.
@ -624,8 +650,10 @@ int demodEM4x05resp(uint8_t bitsNeeded) {
}
if (demodFound && bitsNeeded < DemodBufferLen) {
if (bitsNeeded > 0) {
setDemodBuf(DemodBuffer + ans + sizeof(preamble), bitsNeeded, 0);
CmdPrintDemodBuff("x");
}
return 1;
}
return -1;
@ -673,10 +701,9 @@ int CmdReadWord(const char *Cmd) {
return -1;
}
//need 32 bits for read word
demodEM4x05resp(32);
return 1;
//attempt demod:
//need 32 bits from a read word
return demodEM4x05resp(32);
}
int usage_lf_em_write(void) {
@ -739,26 +766,15 @@ int CmdWriteWord(const char *Cmd) {
}
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 -3;
}
//todo: check response for 00001010 then write data for write confirmation!
//todo: check response for 00001010 then write data for write confirmation!
size_t startIdx = 0, size = DemodBufferLen;
uint8_t preamble[8] = {0,0,0,0,1,0,1,0};
if (!preambleSearch(DemodBuffer, preamble, sizeof(preamble), &size, &startIdx)){
if (g_debugMode) PrintAndLog("DEBUG: Error - EM4305 preamble not found :: %d", startIdx);
return -4;
//attempt demod:
//need 0 bits demoded (after preamble) to verify write cmd
int result = demodEM4x05resp(0);
if (result == 1) {
PrintAndLog("Write Verified");
}
PrintAndLog("Write OK");
return result;
return 0;
}