From e39a92bb1d876f880ad8cbea82921838422358e8 Mon Sep 17 00:00:00 2001
From: marshmellow42 <marshmellowrf@gmail.com>
Date: Fri, 17 Feb 2017 01:33:27 -0500
Subject: [PATCH 1/1] em4x05 getting better
got the read/dump cmds working pretty well
some tweaking still left to do.
---
armsrc/lfops.c | 10 +-
client/cmdlfem4x.c | 326 ++++++++++++++++++++++-----------------------
common/lfdemod.c | 8 +-
3 files changed, 169 insertions(+), 175 deletions(-)
diff --git a/armsrc/lfops.c b/armsrc/lfops.c
index 1d18c709..29331754 100644
--- a/armsrc/lfops.c
+++ b/armsrc/lfops.c
@@ -1573,12 +1573,12 @@ void SendForward(uint8_t fwd_bit_count) {
// Set up FPGA, 125kHz
LFSetupFPGAForADC(95, true);
-
+
// force 1st mod pulse (start gap must be longer for 4305)
fwd_bit_sz--; //prepare next bit modulation
fwd_write_ptr++;
FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); // field off
- SpinDelayUs(56*8); //55 cycles off (8us each)for 4305
+ SpinDelayUs(55*8); //55 cycles off (8us each)for 4305
FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD);//field on
SpinDelayUs(16*8); //16 cycles on (8us each)
@@ -1628,7 +1628,7 @@ void EM4xReadWord(uint8_t Address, uint32_t Pwd, uint8_t PwdMode) {
SendForward(fwd_bit_count);
// Now do the acquisition
- DoAcquisition_config(TRUE);
+ DoAcquisition_default(30,TRUE);
FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); // field off
LED_A_OFF();
@@ -1656,10 +1656,10 @@ void EM4xWriteWord(uint32_t flag, uint32_t Data, uint32_t Pwd) {
SendForward(fwd_bit_count);
//Wait for write to complete
- SpinDelay(20);
+ //SpinDelay(5);
//Capture response if one exists
- DoAcquisition_config(TRUE);
+ DoAcquisition_default(30, TRUE);
FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); // field off
LED_A_OFF();
diff --git a/client/cmdlfem4x.c b/client/cmdlfem4x.c
index 2d1600f6..16faa848 100644
--- a/client/cmdlfem4x.c
+++ b/client/cmdlfem4x.c
@@ -502,21 +502,21 @@ int CmdEM4x50Read(const char *Cmd)
int usage_lf_em_read(void) {
PrintAndLog("Read EM4x05/EM4x69. Tag must be on antenna. ");
PrintAndLog("");
- PrintAndLog("Usage: lf em readword [h] <address> <pwd>");
+ PrintAndLog("Usage: lf em 4x05readword [h] <address> <pwd>");
PrintAndLog("Options:");
PrintAndLog(" h - this help");
PrintAndLog(" address - memory address to read. (0-15)");
PrintAndLog(" pwd - password (hex) (optional)");
PrintAndLog("samples:");
- PrintAndLog(" lf em readword 1");
- PrintAndLog(" lf em readword 1 11223344");
+ PrintAndLog(" lf em 4x05readword 1");
+ PrintAndLog(" lf em 4x05readword 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) {
+bool 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;
+ if ( size <= pLen ) return false;
// em only sends preamble once, so look for it once in the first x bits
uint8_t foundCnt = 0;
for (size_t idx = 0; idx < size - pLen; idx++){
@@ -526,23 +526,62 @@ uint8_t EMpreambleSearch(uint8_t *BitStream, uint8_t *preamble, size_t pLen, siz
if (foundCnt == 1) {
if (g_debugMode) PrintAndLog("DEBUG: preamble found at %u", idx);
*startIdx = idx;
- return 1;
+
+ return true;
}
}
}
- return 0;
+ return false;
+}
+
+bool EM4x05testDemodReadData(uint32_t *word, bool readCmd) {
+ // skip first two 0 bits as they might have been missed in the demod
+ uint8_t preamble[6] = {0,0,1,0,1,0};
+ size_t startIdx = 0;
+ // set size to 10 to only test first 4 positions for the preamble
+ size_t size = (10 > DemodBufferLen) ? DemodBufferLen : 10;
+ startIdx = 0;
+
+ //test preamble
+ bool errChk = EMpreambleSearch(DemodBuffer, preamble, sizeof(preamble), size, &startIdx);
+ if ( !errChk ) {
+ if (g_debugMode) PrintAndLog("DEBUG: Error - EM4305 preamble not found :: %d", startIdx);
+ return false;
+ }
+ if (readCmd) {
+ //test for even parity bits.
+ size = removeParity(DemodBuffer, startIdx + sizeof(preamble),9,0,44);
+ if (size == 0) {
+ if (g_debugMode) PrintAndLog("DEBUG: Error - Parity not detected");
+ return false;
+ }
+
+ //todo test last 8 bits for even parity || (xor)
+
+ setDemodBuf(DemodBuffer, 40, 0);
+
+ *word = bytebits_to_byteLSBF(DemodBuffer , 32);
+
+ uint8_t lo = (uint8_t) bytebits_to_byteLSBF(DemodBuffer , 8);
+ uint8_t lo2 = (uint8_t) bytebits_to_byteLSBF(DemodBuffer + 8, 8);
+ uint8_t hi = (uint8_t) bytebits_to_byteLSBF(DemodBuffer + 16, 8);
+ uint8_t hi2 = (uint8_t) bytebits_to_byteLSBF(DemodBuffer + 24, 8);
+ uint8_t cs = (uint8_t) bytebits_to_byteLSBF(DemodBuffer + 32, 8);
+ uint8_t cs2 = lo ^ lo2 ^ hi ^ hi2;
+ if (g_debugMode) PrintAndLog("EM4x05/4x69 : %08X CS: %02X %s",*word,cs, (cs2==cs) ? "Passed" : "Failed");
+
+ return (cs2==cs) ? true : false;
+ }
+ return true;
}
// 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 demodEM4x05resp(uint32_t *word, bool readCmd) {
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};
- size_t startIdx = 0;
// test for FSK wave (easiest to 99% ID)
if (GetFskClock("", FALSE, FALSE)) {
@@ -551,19 +590,8 @@ int demodEM4x05resp(uint8_t bitsNeeded) {
if (!ans) {
if (g_debugMode) PrintAndLog("DEBUG: Error - EM4305: FSK Demod failed");
} else {
- // set size to 10 to only test first 4 positions for the preamble
- size_t size = (10 > DemodBufferLen) ? DemodBufferLen : 10;
- 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 (EM4x05testDemodReadData(word, readCmd)) {
+ return 1;
}
}
}
@@ -584,19 +612,8 @@ int demodEM4x05resp(uint8_t bitsNeeded) {
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;
- 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 (EM4x05testDemodReadData(word, readCmd)) {
+ return 1;
}
}
}
@@ -608,19 +625,8 @@ int demodEM4x05resp(uint8_t bitsNeeded) {
if (!ans) {
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;
- 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 (EM4x05testDemodReadData(word, readCmd)) {
+ return 1;
}
}
}
@@ -632,53 +638,23 @@ int demodEM4x05resp(uint8_t bitsNeeded) {
if (!ans) {
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;
- 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 (EM4x05testDemodReadData(word, readCmd)) {
+ return 1;
}
}
}
- if (demodFound && bitsNeeded < DemodBufferLen) {
+ /*if (demodFound && bitsNeeded < DemodBufferLen) {
if (bitsNeeded > 0) {
setDemodBuf(DemodBuffer + startIdx + sizeof(preamble), bitsNeeded, 0);
CmdPrintDemodBuff("x");
}
return 1;
- }
+ }*/
return -1;
}
-int CmdReadWord(const char *Cmd) {
- int addr, pwd;
- bool usePwd = false;
- uint8_t ctmp = param_getchar(Cmd, 0);
- if ( strlen(Cmd) == 0 || ctmp == 'H' || ctmp == 'h' ) return usage_lf_em_read();
-
- addr = param_get8ex(Cmd, 0, -1, 10);
- pwd = param_get32ex(Cmd, 1, -1, 16);
-
- if ( (addr > 15) || (addr < 0 ) || ( addr == -1) ) {
- PrintAndLog("Address must be between 0 and 15");
- return 1;
- }
- if ( pwd == -1 )
- PrintAndLog("Reading address %d", addr);
- else {
- usePwd = true;
- PrintAndLog("Reading address %d | password %08X", addr, pwd);
- }
-
+int EM4x05ReadWord(uint8_t addr, uint32_t pwd, bool usePwd) {
UsbCommand c = {CMD_EM4X_READ_WORD, {addr, pwd, usePwd}};
clearCommandBuffer();
SendCommand(&c);
@@ -700,47 +676,115 @@ int CmdReadWord(const char *Cmd) {
PrintAndLog("no tag not found");
return -1;
}
-
//attempt demod:
- //need 32 bits from a read word
- return demodEM4x05resp(44);
+ uint32_t wordData = 0;
+ int success = demodEM4x05resp(&wordData, true);
+ if (success == 1) PrintAndLog("Got Address %02d | %08X",addr,wordData);
+ return success;
+}
+
+int CmdEM4x05ReadWord(const char *Cmd) {
+ uint8_t addr;
+ uint32_t pwd;
+ bool usePwd = false;
+ uint8_t ctmp = param_getchar(Cmd, 0);
+ if ( strlen(Cmd) == 0 || ctmp == 'H' || ctmp == 'h' ) return usage_lf_em_read();
+
+ addr = param_get8ex(Cmd, 0, 50, 10);
+ // for now use default input of 1 as invalid (unlikely 1 will be a valid password...)
+ pwd = param_get32ex(Cmd, 1, 1, 16);
+
+ if ( (addr > 15) ) {
+ PrintAndLog("Address must be between 0 and 15");
+ return 1;
+ }
+ if ( pwd == 1 )
+ PrintAndLog("Reading address %02u", addr);
+ else {
+ usePwd = true;
+ PrintAndLog("Reading address %02u | password %08X", addr, pwd);
+ }
+ return EM4x05ReadWord(addr, pwd, usePwd);
}
+int usage_lf_em_dump(void) {
+ PrintAndLog("Dump EM4x05/EM4x69. Tag must be on antenna. ");
+ PrintAndLog("");
+ PrintAndLog("Usage: lf em 4x05dump [h] <pwd>");
+ PrintAndLog("Options:");
+ PrintAndLog(" h - this help");
+ PrintAndLog(" pwd - password (hex) (optional)");
+ PrintAndLog("samples:");
+ PrintAndLog(" lf em 4x05dump");
+ PrintAndLog(" lf em 4x05dump 11223344");
+ return 0;
+}
+
+int CmdEM4x05dump(const char *Cmd) {
+ uint8_t addr = 0;
+ uint32_t pwd;
+ bool usePwd = false;
+ uint8_t ctmp = param_getchar(Cmd, 0);
+ if ( ctmp == 'H' || ctmp == 'h' ) return usage_lf_em_dump();
+
+ // for now use default input of 1 as invalid (unlikely 1 will be a valid password...)
+ pwd = param_get32ex(Cmd, 0, 1, 16);
+
+ if ( pwd != 1 ) {
+ usePwd = true;
+ }
+ int success = 1;
+ for (; addr < 16; addr++) {
+ if (addr == 2) {
+ if (usePwd) {
+ PrintAndLog("PWD Address %02u | %08X",addr,pwd);
+ } else {
+ PrintAndLog("PWD Address 02 | cannot read");
+ }
+ } else {
+ success &= EM4x05ReadWord(addr, pwd, usePwd);
+ }
+ }
+
+ return success;
+}
+
+
int usage_lf_em_write(void) {
PrintAndLog("Write EM4x05/EM4x69. Tag must be on antenna. ");
PrintAndLog("");
- PrintAndLog("Usage: lf em writeword [h] <address> <data> <pwd>");
+ PrintAndLog("Usage: lf em 4x05writeword [h] <address> <data> <pwd>");
PrintAndLog("Options:");
PrintAndLog(" h - this help");
PrintAndLog(" address - memory address to write to. (0-15)");
PrintAndLog(" data - data to write (hex)");
PrintAndLog(" pwd - password (hex) (optional)");
PrintAndLog("samples:");
- PrintAndLog(" lf em writeword 1");
- PrintAndLog(" lf em writeword 1 deadc0de 11223344");
+ PrintAndLog(" lf em 4x05writeword 1");
+ PrintAndLog(" lf em 4x05writeword 1 deadc0de 11223344");
return 0;
}
-int CmdWriteWord(const char *Cmd) {
+int CmdEM4x05WriteWord(const char *Cmd) {
uint8_t ctmp = param_getchar(Cmd, 0);
if ( strlen(Cmd) == 0 || ctmp == 'H' || ctmp == 'h' ) return usage_lf_em_write();
bool usePwd = false;
- int addr = 16; // default to invalid address
- int data = 0xFFFFFFFF; // default to blank data
- int pwd = 0xFFFFFFFF; // default to blank password
+ uint8_t addr = 16; // default to invalid address
+ uint32_t data = 0xFFFFFFFF; // default to blank data
+ uint32_t pwd = 0xFFFFFFFF; // default to blank password
- addr = param_get8ex(Cmd, 0, -1, 10);
- data = param_get32ex(Cmd, 1, -1, 16);
- pwd = param_get32ex(Cmd, 2, -1, 16);
+ addr = param_get8ex(Cmd, 0, 16, 10);
+ data = param_get32ex(Cmd, 1, 0, 16);
+ pwd = param_get32ex(Cmd, 2, 1, 16);
- if ( (addr > 15) || (addr < 0 ) || ( addr == -1) ) {
+ if ( (addr > 15) ) {
PrintAndLog("Address must be between 0 and 15");
return 1;
}
- if ( pwd == -1 )
+ if ( pwd == 1 )
PrintAndLog("Writing address %d data %08X", addr, data);
else {
usePwd = true;
@@ -753,93 +797,41 @@ int CmdWriteWord(const char *Cmd) {
clearCommandBuffer();
SendCommand(&c);
UsbCommand resp;
- if (!WaitForResponseTimeout(CMD_ACK, &resp, 1000)){
+ if (!WaitForResponseTimeout(CMD_ACK, &resp, 2000)){
PrintAndLog("Error occurred, device did not respond during write operation.");
return -1;
}
//get response if there is one
uint8_t got[6000]; // 8 bit preamble + 32 bit word response (max clock (128) * 40bits = 5120 samples)
GetFromBigBuf(got, sizeof(got), 0);
- if ( !WaitForResponseTimeout(CMD_ACK, NULL, 8000) ) {
+ if ( !WaitForResponseTimeout(CMD_ACK, NULL, 4000) ) {
PrintAndLog("command execution time out");
return 0;
}
setGraphBuf(got, sizeof(got));
- //todo: check response for 00001010 then write data for write confirmation!
-
+ //check response for 00001010 for write confirmation!
//attempt demod:
- //need 0 bits demoded (after preamble) to verify write cmd
- int result = demodEM4x05resp(0);
+ uint32_t dummy = 0;
+ int result = demodEM4x05resp(&dummy,false);
if (result == 1) {
PrintAndLog("Write Verified");
}
return result;
}
-/*
-int CmdWriteWord(const char *Cmd)
-{
- int Word = 16; //default to invalid block
- int Data = 0xFFFFFFFF; //default to blank data
- UsbCommand c;
-
- sscanf(Cmd, "%x %d", &Data, &Word);
-
- if (Word > 15) {
- PrintAndLog("Word must be between 0 and 15");
- return 1;
- }
-
- PrintAndLog("Writing word %d with data %08X", Word, Data);
-
- c.cmd = CMD_EM4X_WRITE_WORD;
- c.d.asBytes[0] = 0x0; //Normal mode
- c.arg[0] = Data;
- c.arg[1] = Word;
- c.arg[2] = 0;
- SendCommand(&c);
- return 0;
-}
-
-int CmdWriteWordPWD(const char *Cmd)
-{
- int Word = 16; //default to invalid word
- int Data = 0xFFFFFFFF; //default to blank data
- int Password = 0xFFFFFFFF; //default to blank password
- UsbCommand c;
-
- sscanf(Cmd, "%x %d %x", &Data, &Word, &Password);
-
- if (Word > 15) {
- PrintAndLog("Word must be between 0 and 15");
- return 1;
- }
-
- PrintAndLog("Writing word %d with data %08X and password %08X", Word, Data, Password);
-
- c.cmd = CMD_EM4X_WRITE_WORD;
- c.d.asBytes[0] = 0x1; //Password mode
- c.arg[0] = Data;
- c.arg[1] = Word;
- c.arg[2] = Password;
- SendCommand(&c);
- return 0;
-}
-*/
static command_t CommandTable[] =
{
{"help", CmdHelp, 1, "This help"},
- {"em410xdemod", CmdEMdemodASK, 0, "[findone] -- Extract ID from EM410x tag (option 0 for continuous loop, 1 for only 1 tag)"},
- {"em410xread", CmdEM410xRead, 1, "[clock rate] -- Extract ID from EM410x tag in GraphBuffer"},
- {"em410xsim", CmdEM410xSim, 0, "<UID> [clock rate] -- Simulate EM410x tag"},
- {"em410xwatch", CmdEM410xWatch, 0, "['h'] -- Watches for EM410x 125/134 kHz tags (option 'h' for 134)"},
- {"em410xspoof", CmdEM410xWatchnSpoof, 0, "['h'] --- Watches for EM410x 125/134 kHz tags, and replays them. (option 'h' for 134)" },
- {"em410xwrite", CmdEM410xWrite, 0, "<UID> <'0' T5555> <'1' T55x7> [clock rate] -- Write EM410x UID to T5555(Q5) or T55x7 tag, optionally setting clock rate"},
- {"em4x50read", CmdEM4x50Read, 1, "demod data from EM4x50 tag from the graph buffer"},
- {"readword", CmdReadWord, 1, "<Word> (pwd) -- Read EM4x05/EM4x69 word data"},
- //{"readwordPWD", CmdReadWordPWD, 1, "<Word> <Password> -- Read EM4xxx word data in password mode"},
- {"writeword", CmdWriteWord, 1, "<Word> <data> (pwd) -- Write EM4x05/EM4x69 word data"},
- //{"writewordPWD", CmdWriteWordPWD, 1, "<Data> <Word> <Password> -- Write EM4xxx word data in password mode"},
+ {"410xdemod", CmdEMdemodASK, 0, "[findone] -- Extract ID from EM410x tag (option 0 for continuous loop, 1 for only 1 tag)"},
+ {"410xread", CmdEM410xRead, 1, "[clock rate] -- Extract ID from EM410x tag in GraphBuffer"},
+ {"410xsim", CmdEM410xSim, 0, "<UID> [clock rate] -- Simulate EM410x tag"},
+ {"410xwatch", CmdEM410xWatch, 0, "['h'] -- Watches for EM410x 125/134 kHz tags (option 'h' for 134)"},
+ {"410xspoof", CmdEM410xWatchnSpoof, 0, "['h'] --- Watches for EM410x 125/134 kHz tags, and replays them. (option 'h' for 134)" },
+ {"410xwrite", CmdEM410xWrite, 0, "<UID> <'0' T5555> <'1' T55x7> [clock rate] -- Write EM410x UID to T5555(Q5) or T55x7 tag, optionally setting clock rate"},
+ {"4x05dump", CmdEM4x05dump, 1, "(pwd) -- Read EM4x05/EM4x69 all word data"},
+ {"4x05readword", CmdEM4x05ReadWord, 1, "<Word> (pwd) -- Read EM4x05/EM4x69 word data"},
+ {"4x05writeword", CmdEM4x05WriteWord, 1, "<Word> <data> (pwd) -- Write EM4x05/EM4x69 word data"},
+ {"4x50read", CmdEM4x50Read, 1, "demod data from EM4x50 tag from the graph buffer"},
{NULL, NULL, 0, NULL}
};
diff --git a/common/lfdemod.c b/common/lfdemod.c
index f9f2d1f1..2ee66a52 100644
--- a/common/lfdemod.c
+++ b/common/lfdemod.c
@@ -62,7 +62,7 @@ uint8_t parityTest(uint32_t bits, uint8_t bitLen, uint8_t pType)
for (uint8_t i = 0; i < bitLen; i++){
ans ^= ((bits >> i) & 1);
}
- //PrintAndLog("DEBUG: ans: %d, ptype: %d",ans,pType);
+ if (g_debugMode) prnt("DEBUG: ans: %d, ptype: %d, bits: %08X",ans,pType,bits);
return (ans == pType);
}
@@ -73,11 +73,13 @@ size_t removeParity(uint8_t *BitStream, size_t startIdx, uint8_t pLen, uint8_t p
{
uint32_t parityWd = 0;
size_t j = 0, bitCnt = 0;
- for (int word = 0; word < (bLen); word+=pLen){
- for (int bit=0; bit < pLen; bit++){
+ for (int word = 0; word < (bLen); word+=pLen) {
+ for (int bit=0; bit < pLen; bit++) {
parityWd = (parityWd << 1) | BitStream[startIdx+word+bit];
BitStream[j++] = (BitStream[startIdx+word+bit]);
}
+ if (word+pLen >= bLen) break;
+
j--; // overwrite parity with next data
// if parity fails then return 0
switch (pType) {
--
2.39.5