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fixing iso 14443b (issue #103):

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- fix: treat empty commands as error
- deleting dead code
- rename USB-Commands (ISO14443 -> iso14443B)
This commit is contained in:
pwpiwi 2015-06-18 09:49:22 +02:00
commit 132a02179c
6 changed files with 42 additions and 250 deletions
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144
client/cmdhf14b.c
View file

@ -25,154 +25,23 @@
static int CmdHelp(const char *Cmd);
int CmdHF14BDemod(const char *Cmd)
{
int i, j, iold;
int isum, qsum;
int outOfWeakAt;
bool negateI, negateQ;
uint8_t data[256];
int dataLen = 0;
// As received, the samples are pairs, correlations against I and Q
// square waves. So estimate angle of initial carrier (or just
// quadrant, actually), and then do the demod.
// First, estimate where the tag starts modulating.
for (i = 0; i < GraphTraceLen; i += 2) {
if (abs(GraphBuffer[i]) + abs(GraphBuffer[i + 1]) > 40) {
break;
}
}
if (i >= GraphTraceLen) {
PrintAndLog("too weak to sync");
return 0;
}
PrintAndLog("out of weak at %d", i);
outOfWeakAt = i;
// Now, estimate the phase in the initial modulation of the tag
isum = 0;
qsum = 0;
for (; i < (outOfWeakAt + 16); i += 2) {
isum += GraphBuffer[i + 0];
qsum += GraphBuffer[i + 1];
}
negateI = (isum < 0);
negateQ = (qsum < 0);
// Turn the correlation pairs into soft decisions on the bit.
j = 0;
for (i = 0; i < GraphTraceLen / 2; i++) {
int si = GraphBuffer[j];
int sq = GraphBuffer[j + 1];
if (negateI) si = -si;
if (negateQ) sq = -sq;
GraphBuffer[i] = si + sq;
j += 2;
}
GraphTraceLen = i;
i = outOfWeakAt / 2;
while (GraphBuffer[i] > 0 && i < GraphTraceLen)
i++;
if (i >= GraphTraceLen) goto demodError;
iold = i;
while (GraphBuffer[i] < 0 && i < GraphTraceLen)
i++;
if (i >= GraphTraceLen) goto demodError;
if ((i - iold) > 23) goto demodError;
PrintAndLog("make it to demod loop");
for (;;) {
iold = i;
while (GraphBuffer[i] >= 0 && i < GraphTraceLen)
i++;
if (i >= GraphTraceLen) goto demodError;
if ((i - iold) > 6) goto demodError;
uint16_t shiftReg = 0;
if (i + 20 >= GraphTraceLen) goto demodError;
for (j = 0; j < 10; j++) {
int soft = GraphBuffer[i] + GraphBuffer[i + 1];
if (abs(soft) < (abs(isum) + abs(qsum)) / 20) {
PrintAndLog("weak bit");
}
shiftReg >>= 1;
if(GraphBuffer[i] + GraphBuffer[i+1] >= 0) {
shiftReg |= 0x200;
}
i+= 2;
}
if ((shiftReg & 0x200) && !(shiftReg & 0x001))
{
// valid data byte, start and stop bits okay
PrintAndLog(" %02x", (shiftReg >> 1) & 0xff);
data[dataLen++] = (shiftReg >> 1) & 0xff;
if (dataLen >= sizeof(data)) {
return 0;
}
} else if (shiftReg == 0x000) {
// this is EOF
break;
} else {
goto demodError;
}
}
uint8_t first, second;
ComputeCrc14443(CRC_14443_B, data, dataLen-2, &first, &second);
PrintAndLog("CRC: %02x %02x (%s)\n", first, second,
(first == data[dataLen-2] && second == data[dataLen-1]) ?
"ok" : "****FAIL****");
RepaintGraphWindow();
return 0;
demodError:
PrintAndLog("demod error");
RepaintGraphWindow();
return 0;
}
int CmdHF14BList(const char *Cmd)
{
PrintAndLog("Deprecated command, use 'hf list 14b' instead");
return 0;
}
int CmdHF14BRead(const char *Cmd)
{
UsbCommand c = {CMD_ACQUIRE_RAW_ADC_SAMPLES_ISO_14443, {strtol(Cmd, NULL, 0), 0, 0}};
SendCommand(&c);
return 0;
}
int CmdHF14Sim(const char *Cmd)
int CmdHF14BSim(const char *Cmd)
{
UsbCommand c={CMD_SIMULATE_TAG_ISO_14443};
SendCommand(&c);
return 0;
}
int CmdHFSimlisten(const char *Cmd)
{
UsbCommand c = {CMD_SIMULATE_TAG_HF_LISTEN};
UsbCommand c={CMD_SIMULATE_TAG_ISO_14443B};
SendCommand(&c);
return 0;
}
int CmdHF14BSnoop(const char *Cmd)
{
UsbCommand c = {CMD_SNOOP_ISO_14443};
UsbCommand c = {CMD_SNOOP_ISO_14443B};
SendCommand(&c);
return 0;
}
@ -387,12 +256,9 @@ int CmdHF14BWrite( const char *Cmd){
static command_t CommandTable[] =
{
{"help", CmdHelp, 1, "This help"},
{"demod", CmdHF14BDemod, 1, "Demodulate ISO14443 Type B from tag"},
{"list", CmdHF14BList, 0, "[Deprecated] List ISO 14443b history"},
{"read", CmdHF14BRead, 0, "Read HF tag (ISO 14443)"},
{"sim", CmdHF14Sim, 0, "Fake ISO 14443 tag"},
{"simlisten", CmdHFSimlisten, 0, "Get HF samples as fake tag"},
{"snoop", CmdHF14BSnoop, 0, "Eavesdrop ISO 14443"},
{"sim", CmdHF14BSim, 0, "Fake ISO 14443B tag"},
{"snoop", CmdHF14BSnoop, 0, "Eavesdrop ISO 14443B"},
{"sri512read", CmdSri512Read, 0, "Read contents of a SRI512 tag"},
{"srix4kread", CmdSrix4kRead, 0, "Read contents of a SRIX4K tag"},
{"raw", CmdHF14BCmdRaw, 0, "Send raw hex data to tag"},