From: iceman1001 <iceman@iuse.se>
Date: Wed, 15 Feb 2017 15:58:29 +0000 (+0100)
Subject: CHG: `lf em` - @marshmellow42 's latest changes
X-Git-Url: https://git.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] <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");
- 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] <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;