ADD: a TEA crypto algorithm implemention.

[proxmark3-svn] / armsrc / iso14443b.c

diff --git a/armsrc/iso14443b.c b/armsrc/iso14443b.c
index 7423a8ed335b60c9782e3f6e60cb122af5cc8334..0b9962e1e5cf5ffe727051163ede8e9a4c0d6aad 100644 (file)
--- a/armsrc/iso14443b.c
+++ b/armsrc/iso14443b.c
@@ -15,7 +15,7 @@
 #include "string.h"
 #include "iso14443crc.h"
 #include "common.h"
-#define RECEIVE_SAMPLES_TIMEOUT 800000
+#define RECEIVE_SAMPLES_TIMEOUT 600000
 #define ISO14443B_DMA_BUFFER_SIZE 256
 
 
@@ -106,7 +106,7 @@ static void CodeIso14443bAsTag(const uint8_t *cmd, int len)
                ToSendStuffBit(0);
                ToSendStuffBit(0);
        }
-       for(i = 0; i < 10; i++) {
+       for(i = 0; i < 2; i++) {
                ToSendStuffBit(1);
                ToSendStuffBit(1);
                ToSendStuffBit(1);
@@ -479,6 +479,7 @@ void SimulateIso14443bTag(void)
                if (tracing) LogTrace(resp, respLen, 0, 0, parity, FALSE);                      
        }
        FpgaDisableSscDma();
+       set_tracing(FALSE);     
 }
 
 //=============================================================================
@@ -525,15 +526,23 @@ static struct {
  *          false if we are still waiting for some more
  *
  */
+ #define abs(x) ( ((x)<0) ? -(x) : (x) )
 static RAMFUNC int Handle14443bSamplesDemod(int ci, int cq)
 {
-       int v;
-       int ai, aq;
+       int v = 0;
+       int ai = abs(ci);
+       int aq = abs(cq);
+       int halfci = (ai >> 1);
+       int halfcq = (aq >> 1);
 
 // The soft decision on the bit uses an estimate of just the
 // quadrant of the reference angle, not the exact angle.
 #define MAKE_SOFT_DECISION() { \
-               v = (Demod.sumI > 0) ? ci : -ci;\
+               if(Demod.sumI > 0) { \
+                       v = ci; \
+               } else { \
+                       v = -ci; \
+               } \
                if(Demod.sumQ > 0) { \
                        v += cq; \
                } else { \
@@ -543,23 +552,9 @@ static RAMFUNC int Handle14443bSamplesDemod(int ci, int cq)
 
 #define SUBCARRIER_DETECT_THRESHOLD    8
 
-// Subcarrier amplitude v = sqrt(ci^2 + cq^2), approximated here by abs(ci) + abs(cq)
-/* #define CHECK_FOR_SUBCARRIER() { \
-               v = ci; \
-               if(v < 0) v = -v; \
-               if(cq > 0) { \
-                       v += cq; \
-               } else { \
-                       v -= cq; \
-               } \
-       }               
- */
-
 // Subcarrier amplitude v = sqrt(ci^2 + cq^2), approximated here by max(abs(ci),abs(cq)) + 1/2*min(abs(ci),abs(cq)))
 #define CHECK_FOR_SUBCARRIER() { \
-               ai = (abs(ci) >> 1); \
-               aq = (abs(cq) >> 1); \
-               v = MAX(abs(ci), abs(cq)) + MIN(ai, aq); \
+               v = MAX(ai, aq) + MIN(halfci, halfcq); \
 }
 
 
@@ -575,7 +570,8 @@ static RAMFUNC int Handle14443bSamplesDemod(int ci, int cq)
                        break;
 
                case DEMOD_PHASE_REF_TRAINING:
-                       if(Demod.posCount < 10*2) {
+                       if(Demod.posCount < 8) {
+                       //if(Demod.posCount < 10*2) {
                                CHECK_FOR_SUBCARRIER();
                                if (v > SUBCARRIER_DETECT_THRESHOLD) {
                                        // set the reference phase (will code a logic '1') by averaging over 32 1/fs.
@@ -594,7 +590,7 @@ static RAMFUNC int Handle14443bSamplesDemod(int ci, int cq)
                case DEMOD_AWAITING_FALLING_EDGE_OF_SOF:
                        MAKE_SOFT_DECISION();
                        //Dbprintf("ICE: %d %d %d %d %d", v, Demod.sumI, Demod.sumQ, ci, cq );
-                       if(v < 0) {     // logic '0' detected
+                       if(v <= 0) {    // logic '0' detected
                                Demod.state = DEMOD_GOT_FALLING_EDGE_OF_SOF;
                                Demod.posCount = 0;     // start of SOF sequence
                        } else {
@@ -767,7 +763,7 @@ static void GetSamplesFor14443bDemod(int n, bool quiet)
                        }
                        lastRxCounter -= 2;
                        if(lastRxCounter <= 0) {
-                               lastRxCounter += ISO14443B_DMA_BUFFER_SIZE;
+                               lastRxCounter = ISO14443B_DMA_BUFFER_SIZE;
                        }
 
                        samples += 2;
@@ -1012,6 +1008,8 @@ void iso14443b_setup() {
        // Signal field is on with the appropriate LED
     LED_D_ON();
        FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_TX | FPGA_HF_READER_TX_SHALLOW_MOD);
+       
+       //SpinDelay(100);
 
        // Start the timer
        //StartCountSspClk();
@@ -1061,6 +1059,7 @@ void ReadSTMemoryIso14443b(uint32_t dwLast)
 
        if (Demod.len == 0) {
                DbpString("No response from tag");
+               set_tracing(FALSE);     
                return;
        } else {
                Dbprintf("Randomly generated Chip ID (+ 2 byte CRC): %02x %02x %02x",
@@ -1076,17 +1075,20 @@ void ReadSTMemoryIso14443b(uint32_t dwLast)
        GetSamplesFor14443bDemod(RECEIVE_SAMPLES_TIMEOUT, TRUE);
        if (Demod.len != 3) {
                Dbprintf("Expected 3 bytes from tag, got %d", Demod.len);
+               set_tracing(FALSE);     
                return;
        }
        // Check the CRC of the answer:
        ComputeCrc14443(CRC_14443_B, Demod.output, 1 , &cmd1[2], &cmd1[3]);
        if(cmd1[2] != Demod.output[1] || cmd1[3] != Demod.output[2]) {
                DbpString("CRC Error reading select response.");
+               set_tracing(FALSE);     
                return;
        }
        // Check response from the tag: should be the same UID as the command we just sent:
        if (cmd1[1] != Demod.output[0]) {
                Dbprintf("Bad response to SELECT from Tag, aborting: %02x %02x", cmd1[1], Demod.output[0]);
+               set_tracing(FALSE);     
                return;
        }
 
@@ -1098,6 +1100,7 @@ void ReadSTMemoryIso14443b(uint32_t dwLast)
        GetSamplesFor14443bDemod(RECEIVE_SAMPLES_TIMEOUT, TRUE);
        if (Demod.len != 10) {
                Dbprintf("Expected 10 bytes from tag, got %d", Demod.len);
+               set_tracing(FALSE);     
                return;
        }
        // The check the CRC of the answer (use cmd1 as temporary variable):
@@ -1145,6 +1148,8 @@ void ReadSTMemoryIso14443b(uint32_t dwLast)
                }
                i++;
        }
+       
+       set_tracing(FALSE);
 }
 
 
@@ -1278,7 +1283,7 @@ void RAMFUNC SnoopIso14443b(void)
 
                if(!ReaderIsActive) {                                           // no need to try decoding tag data if the reader is sending - and we cannot afford the time
                        // is this | 0x01 the error?   & 0xfe  in https://github.com/Proxmark/proxmark3/issues/103
-                       if(Handle14443bSamplesDemod(ci | 0x01, cq | 0x01)) {
+                       if(Handle14443bSamplesDemod(ci & 0xfe, cq & 0xfe)) {
 
                        //Use samples as a time measurement
                        if(tracing)
@@ -1293,11 +1298,12 @@ void RAMFUNC SnoopIso14443b(void)
                }
                        TagIsActive = (Demod.state > DEMOD_GOT_FALLING_EDGE_OF_SOF);
                }
-
        }
 
        FpgaDisableSscDma();
        LEDsoff();
+       set_tracing(FALSE);     
+               
        AT91C_BASE_PDC_SSC->PDC_PTCR = AT91C_PDC_RXTDIS;
        DbpString("Snoop statistics:");
        Dbprintf("  Max behind by: %i", maxBehindBy);
@@ -1340,6 +1346,7 @@ void SendRawCommand14443B(uint32_t datalen, uint32_t recv, uint8_t powerfield, u
        if(!powerfield) {
                FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
                FpgaDisableSscDma();
+               set_tracing(FALSE);
                LED_D_OFF();
        }
 }