]> git.zerfleddert.de Git - proxmark3-svn/blobdiff - armsrc/iso14443a.c
Fixed several issues found using a coverity-scan
[proxmark3-svn] / armsrc / iso14443a.c
index b105e792d3af7f5d4ca7e672a378912764af7b1e..9a80a17723b3ca4e6a4f392a21fc4166d5b8a9f2 100644 (file)
@@ -42,15 +42,14 @@ static uint8_t iso14_pcb_blocknum = 0;
 //
 // Total delays including SSC-Transfers between ARM and FPGA. These are in carrier clock cycles (1/13,56MHz)
 //
-// When the PM acts as reader and is receiving, it takes 
-// 3 ticks for the A/D conversion
-// 10 ticks ( 16 on average) delay in the modulation detector.
-// 6 ticks until the SSC samples the first data
-// 7*16 ticks to complete the transfer from FPGA to ARM
-// 8 ticks to the next ssp_clk rising edge
+// When the PM acts as reader and is receiving tag data, it takes
+// 3 ticks delay in the AD converter
+// 16 ticks until the modulation detector completes and sets curbit
+// 8 ticks until bit_to_arm is assigned from curbit
+// 8*16 ticks for the transfer from FPGA to ARM
 // 4*16 ticks until we measure the time
 // - 8*16 ticks because we measure the time of the previous transfer 
-#define DELAY_AIR2ARM_AS_READER (3 + 10 + 6 + 7*16 + 8 + 4*16 - 8*16) 
+#define DELAY_AIR2ARM_AS_READER (3 + 16 + 8 + 8*16 + 4*16 - 8*16) 
 
 // When the PM acts as a reader and is sending, it takes
 // 4*16 ticks until we can write data to the sending hold register
@@ -61,15 +60,15 @@ static uint8_t iso14_pcb_blocknum = 0;
 #define DELAY_ARM2AIR_AS_READER (4*16 + 8*16 + 8 + 8 + 1)
 
 // When the PM acts as tag and is receiving it takes
-// 12 ticks delay in the RF part,
+// 2 ticks delay in the RF part (for the first falling edge),
 // 3 ticks for the A/D conversion,
 // 8 ticks on average until the start of the SSC transfer,
 // 8 ticks until the SSC samples the first data
 // 7*16 ticks to complete the transfer from FPGA to ARM
 // 8 ticks until the next ssp_clk rising edge
-// 3*16 ticks until we measure the time 
+// 4*16 ticks until we measure the time 
 // - 8*16 ticks because we measure the time of the previous transfer 
-#define DELAY_AIR2ARM_AS_TAG (12 + 3 + 8 + 8 + 7*16 + 8 + 3*16 - 8*16)
+#define DELAY_AIR2ARM_AS_TAG (2 + 3 + 8 + 8 + 7*16 + 8 + 4*16 - 8*16)
  
 // The FPGA will report its internal sending delay in
 uint16_t FpgaSendQueueDelay;
@@ -78,29 +77,30 @@ uint16_t FpgaSendQueueDelay;
 #define DELAY_FPGA_QUEUE (FpgaSendQueueDelay<<1)
 
 // When the PM acts as tag and is sending, it takes
-// 5*16 ticks until we can write data to the sending hold register
+// 4*16 ticks until we can write data to the sending hold register
 // 8*16 ticks until the SHR is transferred to the Sending Shift Register
 // 8 ticks until the first transfer starts
 // 8 ticks later the FPGA samples the data
 // + a varying number of ticks in the FPGA Delay Queue (mod_sig_buf)
 // + 1 tick to assign mod_sig_coil
-#define DELAY_ARM2AIR_AS_TAG (5*16 + 8*16 + 8 + 8 + DELAY_FPGA_QUEUE + 1)
+#define DELAY_ARM2AIR_AS_TAG (4*16 + 8*16 + 8 + 8 + DELAY_FPGA_QUEUE + 1)
 
 // When the PM acts as sniffer and is receiving tag data, it takes
 // 3 ticks A/D conversion
-// 16 ticks delay in the modulation detector (on average).
-// + 16 ticks until it's result is sampled.
+// 14 ticks to complete the modulation detection
+// 8 ticks (on average) until the result is stored in to_arm
 // + the delays in transferring data - which is the same for
 // sniffing reader and tag data and therefore not relevant
-#define DELAY_TAG_AIR2ARM_AS_SNIFFER (3 + 16 + 16
+#define DELAY_TAG_AIR2ARM_AS_SNIFFER (3 + 14 + 8
  
-// When the PM acts as sniffer and is receiving tag data, it takes
-// 12 ticks delay in analogue RF receiver
+// When the PM acts as sniffer and is receiving reader data, it takes
+// 2 ticks delay in analogue RF receiver (for the falling edge of the 
+// start bit, which marks the start of the communication)
 // 3 ticks A/D conversion
-// 8 ticks on average until we sample the data.
+// 8 ticks on average until the data is stored in to_arm.
 // + the delays in transferring data - which is the same for
 // sniffing reader and tag data and therefore not relevant
-#define DELAY_READER_AIR2ARM_AS_SNIFFER (12 + 3 + 8) 
+#define DELAY_READER_AIR2ARM_AS_SNIFFER (2 + 3 + 8) 
 
 //variables used for timing purposes:
 //these are in ssp_clk cycles:
@@ -190,8 +190,9 @@ void AppendCrc14443a(uint8_t* data, int len)
 }
 
 // The function LogTrace() is also used by the iClass implementation in iClass.c
-bool RAMFUNC LogTrace(const uint8_t * btBytes, uint8_t iLen, uint32_t timestamp, uint32_t dwParity, bool bReader)
+bool RAMFUNC LogTrace(const uint8_t * btBytes, uint8_t iLen, uint32_t timestamp, uint32_t dwParity, bool readerToTag)
 {
+       if (!tracing) return FALSE;
        // Return when trace is full
        if (traceLen + sizeof(timestamp) + sizeof(dwParity) + iLen >= TRACE_SIZE) {
                tracing = FALSE;        // don't trace any more
@@ -203,7 +204,8 @@ bool RAMFUNC LogTrace(const uint8_t * btBytes, uint8_t iLen, uint32_t timestamp,
        trace[traceLen++] = ((timestamp >> 8) & 0xff);
        trace[traceLen++] = ((timestamp >> 16) & 0xff);
        trace[traceLen++] = ((timestamp >> 24) & 0xff);
-       if (!bReader) {
+
+       if (!readerToTag) {
                trace[traceLen - 1] |= 0x80;
        }
        trace[traceLen++] = ((dwParity >> 0) & 0xff);
@@ -258,23 +260,7 @@ void UartReset()
        Uart.endTime = 0;
 }
 
-/* inline RAMFUNC Modulation_t MillerModulation(uint8_t b)
-{
-       // switch (b & 0x88) {
-               // case 0x00:   return MILLER_MOD_BOTH_HALVES;
-               // case 0x08:   return MILLER_MOD_FIRST_HALF;
-               // case 0x80:   return MILLER_MOD_SECOND_HALF;
-               // case 0x88:   return MILLER_MOD_NOMOD;
-       // }
-       // test the second cycle for a pause. For whatever reason the startbit tends to appear earlier than the rest.
-       switch (b & 0x44) {
-               case 0x00:      return MOD_BOTH_HALVES;
-               case 0x04:      return MOD_FIRST_HALF;
-               case 0x40:      return MOD_SECOND_HALF;
-               default:        return MOD_NOMOD;
-       }
-}
- */
+
 // use parameter non_real_time to provide a timestamp. Set to 0 if the decoder should measure real time
 static RAMFUNC bool MillerDecoding(uint8_t bit, uint32_t non_real_time)
 {
@@ -398,10 +384,10 @@ static RAMFUNC bool MillerDecoding(uint8_t bit, uint32_t non_real_time)
 static tDemod Demod;
 
 // Lookup-Table to decide if 4 raw bits are a modulation.
-// We accept three or four consecutive "1" in any position
+// We accept three or four "1" in any position
 const bool Mod_Manchester_LUT[] = {
        FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, TRUE,
-       FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, TRUE,  TRUE
+       FALSE, FALSE, FALSE, TRUE,  FALSE, TRUE,  TRUE,  TRUE
 };
 
 #define IsManchesterModulationNibble1(b) (Mod_Manchester_LUT[(b & 0x00F0) >> 4])
@@ -521,6 +507,7 @@ void RAMFUNC SnoopIso14443a(uint8_t param) {
        LEDsoff();
        // init trace buffer
        iso14a_clear_trace();
+       iso14a_set_tracing(TRUE);
 
        // We won't start recording the frames that we acquire until we trigger;
        // a good trigger condition to get started is probably when we see a
@@ -646,7 +633,7 @@ void RAMFUNC SnoopIso14443a(uint8_t param) {
                previous_data = *data;
                rsamples++;
                data++;
-               if(data > dmaBuf + DMA_BUFFER_SIZE) {
+               if(data == dmaBuf + DMA_BUFFER_SIZE) {
                        data = dmaBuf;
                }
        } // main cycle
@@ -1423,7 +1410,7 @@ static int EmSendCmd14443aRaw(uint8_t *resp, int respLen, bool correctionNeeded)
                i = 1;
        }
 
-       // clear receiving shift register and holding register
+       // clear receiving shift register and holding register
        while(!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY));
        b = AT91C_BASE_SSC->SSC_RHR; (void) b;
        while(!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY));
@@ -1779,6 +1766,7 @@ int iso14443a_select_card(byte_t* uid_ptr, iso14a_card_select_t* p_hi14a_card, u
 }
 
 void iso14443a_setup(uint8_t fpga_minor_mode) {
+       FpgaDownloadAndGo(FPGA_BITSTREAM_HF);
        // Set up the synchronous serial port
        FpgaSetupSsc();
        // connect Demodulated Signal to ADC:
@@ -1874,6 +1862,7 @@ void ReaderIso14443a(UsbCommand *c)
                if(param & ISO14A_APPEND_CRC) {
                        AppendCrc14443a(cmd,len);
                        len += 2;
+                       if (lenbits) lenbits += 16;
                }
                if(lenbits>0) {
                        ReaderTransmitBitsPar(cmd,lenbits,GetParity(cmd,lenbits/8), NULL);
@@ -2217,9 +2206,12 @@ void Mifare1ksim(uint8_t flags, uint8_t exitAfterNReads, uint8_t arg2, uint8_t *
 
        if (MF_DBGLEVEL >= 1)   {
                if (!_7BUID) {
-                       Dbprintf("4B UID: %02x%02x%02x%02x",rUIDBCC1[0] , rUIDBCC1[1] , rUIDBCC1[2] , rUIDBCC1[3]);
+                       Dbprintf("4B UID: %02x%02x%02x%02x", 
+                               rUIDBCC1[0], rUIDBCC1[1], rUIDBCC1[2], rUIDBCC1[3]);
                } else {
-                       Dbprintf("7B UID: (%02x)%02x%02x%02x%02x%02x%02x%02x",rUIDBCC1[0] , rUIDBCC1[1] , rUIDBCC1[2] , rUIDBCC1[3],rUIDBCC2[0],rUIDBCC2[1] ,rUIDBCC2[2] , rUIDBCC2[3]);
+                       Dbprintf("7B UID: (%02x)%02x%02x%02x%02x%02x%02x%02x",
+                               rUIDBCC1[0], rUIDBCC1[1], rUIDBCC1[2], rUIDBCC1[3],
+                               rUIDBCC2[0], rUIDBCC2[1] ,rUIDBCC2[2], rUIDBCC2[3]);
                }
        }
 
@@ -2287,7 +2279,7 @@ void Mifare1ksim(uint8_t flags, uint8_t exitAfterNReads, uint8_t arg2, uint8_t *
                                // select card
                                if (len == 9 && 
                                                (receivedCmd[0] == 0x93 && receivedCmd[1] == 0x70 && memcmp(&receivedCmd[2], rUIDBCC1, 4) == 0)) {
-                                       EmSendCmd(_7BUID?rSAK1:rSAK, sizeof(_7BUID?rSAK1:rSAK));
+                                       EmSendCmd(_7BUID?rSAK1:rSAK, _7BUID?sizeof(rSAK1):sizeof(rSAK));
                                        cuid = bytes_to_num(rUIDBCC1, 4);
                                        if (!_7BUID) {
                                                cardSTATE = MFEMUL_WORK;
@@ -2329,10 +2321,13 @@ void Mifare1ksim(uint8_t flags, uint8_t exitAfterNReads, uint8_t arg2, uint8_t *
 
                                // test if auth OK
                                if (cardRr != prng_successor(nonce, 64)){
-                                       if (MF_DBGLEVEL >= 2)   Dbprintf("AUTH FAILED. cardRr=%08x, succ=%08x",cardRr, prng_successor(nonce, 64));
+                                       if (MF_DBGLEVEL >= 2) Dbprintf("AUTH FAILED for sector %d with key %c. cardRr=%08x, succ=%08x",
+                                                       cardAUTHSC, cardAUTHKEY == 0 ? 'A' : 'B',
+                                                       cardRr, prng_successor(nonce, 64));
                                        // Shouldn't we respond anything here?
                                        // Right now, we don't nack or anything, which causes the
                                        // reader to do a WUPA after a while. /Martin
+                                       // -- which is the correct response. /piwi
                                        cardSTATE_TO_IDLE();
                                        LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parityBits, TRUE);
                                        LogTrace(NULL, 0, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, 0, TRUE);
@@ -2346,7 +2341,9 @@ void Mifare1ksim(uint8_t flags, uint8_t exitAfterNReads, uint8_t arg2, uint8_t *
                                EmSendCmd(rAUTH_AT, sizeof(rAUTH_AT));
                                LED_C_ON();
                                cardSTATE = MFEMUL_WORK;
-                               if (MF_DBGLEVEL >= 4)   Dbprintf("AUTH COMPLETED. sector=%d, key=%d time=%d", cardAUTHSC, cardAUTHKEY, GetTickCount() - authTimer);
+                               if (MF_DBGLEVEL >= 4)   Dbprintf("AUTH COMPLETED for sector %d with key %c. time=%d", 
+                                       cardAUTHSC, cardAUTHKEY == 0 ? 'A' : 'B',
+                                       GetTickCount() - authTimer);
                                break;
                        }
                        case MFEMUL_SELECT2:{
@@ -2404,12 +2401,12 @@ void Mifare1ksim(uint8_t flags, uint8_t exitAfterNReads, uint8_t arg2, uint8_t *
                                        crypto1_create(pcs, emlGetKey(cardAUTHSC, cardAUTHKEY));
 
                                        if (!encrypted_data) { // first authentication
-                                               if (MF_DBGLEVEL >= 2) Dbprintf("Reader authenticating for block %d (0x%02x) with key %d",receivedCmd[1] ,receivedCmd[1],cardAUTHKEY  );
+                                               if (MF_DBGLEVEL >= 4) Dbprintf("Reader authenticating for block %d (0x%02x) with key %d",receivedCmd[1] ,receivedCmd[1],cardAUTHKEY  );
 
                                                crypto1_word(pcs, cuid ^ nonce, 0);//Update crypto state
                                                num_to_bytes(nonce, 4, rAUTH_AT); // Send nonce
                                        } else { // nested authentication
-                                               if (MF_DBGLEVEL >= 2) Dbprintf("Reader doing nested authentication for block %d (0x%02x) with key %d",receivedCmd[1] ,receivedCmd[1],cardAUTHKEY );
+                                               if (MF_DBGLEVEL >= 4) Dbprintf("Reader doing nested authentication for block %d (0x%02x) with key %d",receivedCmd[1] ,receivedCmd[1],cardAUTHKEY );
                                                ans = nonce ^ crypto1_word(pcs, cuid ^ nonce, 0); 
                                                num_to_bytes(ans, 4, rAUTH_AT);
                                        }
@@ -2440,9 +2437,9 @@ void Mifare1ksim(uint8_t flags, uint8_t exitAfterNReads, uint8_t arg2, uint8_t *
 
                                if(receivedCmd[0] == 0x30 // read block
                                                || receivedCmd[0] == 0xA0 // write block
-                                               || receivedCmd[0] == 0xC0
-                                               || receivedCmd[0] == 0xC1
-                                               || receivedCmd[0] == 0xC2 // inc dec restore
+                                               || receivedCmd[0] == 0xC0 // inc
+                                               || receivedCmd[0] == 0xC1 // dec
+                                               || receivedCmd[0] == 0xC2 // restore
                                                || receivedCmd[0] == 0xB0) { // transfer
                                        if (receivedCmd[1] >= 16 * 4) {
                                                EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
@@ -2458,7 +2455,7 @@ void Mifare1ksim(uint8_t flags, uint8_t exitAfterNReads, uint8_t arg2, uint8_t *
                                }
                                // read block
                                if (receivedCmd[0] == 0x30) {
-                                       if (MF_DBGLEVEL >= 2) {
+                                       if (MF_DBGLEVEL >= 4) {
                                                Dbprintf("Reader reading block %d (0x%02x)",receivedCmd[1],receivedCmd[1]);
                                        }
                                        emlGetMem(response, receivedCmd[1], 1);
@@ -2474,7 +2471,7 @@ void Mifare1ksim(uint8_t flags, uint8_t exitAfterNReads, uint8_t arg2, uint8_t *
                                }
                                // write block
                                if (receivedCmd[0] == 0xA0) {
-                                       if (MF_DBGLEVEL >= 2) Dbprintf("RECV 0xA0 write block %d (%02x)",receivedCmd[1],receivedCmd[1]);
+                                       if (MF_DBGLEVEL >= 4) Dbprintf("RECV 0xA0 write block %d (%02x)",receivedCmd[1],receivedCmd[1]);
                                        EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
                                        cardSTATE = MFEMUL_WRITEBL2;
                                        cardWRBL = receivedCmd[1];
@@ -2482,7 +2479,7 @@ void Mifare1ksim(uint8_t flags, uint8_t exitAfterNReads, uint8_t arg2, uint8_t *
                                }
                                // increment, decrement, restore
                                if (receivedCmd[0] == 0xC0 || receivedCmd[0] == 0xC1 || receivedCmd[0] == 0xC2) {
-                                       if (MF_DBGLEVEL >= 2) Dbprintf("RECV 0x%02x inc(0xC1)/dec(0xC0)/restore(0xC2) block %d (%02x)",receivedCmd[0],receivedCmd[1],receivedCmd[1]);
+                                       if (MF_DBGLEVEL >= 4) Dbprintf("RECV 0x%02x inc(0xC1)/dec(0xC0)/restore(0xC2) block %d (%02x)",receivedCmd[0],receivedCmd[1],receivedCmd[1]);
                                        if (emlCheckValBl(receivedCmd[1])) {
                                                if (MF_DBGLEVEL >= 2) Dbprintf("Reader tried to operate on block, but emlCheckValBl failed, nacking");
                                                EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
@@ -2500,7 +2497,7 @@ void Mifare1ksim(uint8_t flags, uint8_t exitAfterNReads, uint8_t arg2, uint8_t *
                                }
                                // transfer
                                if (receivedCmd[0] == 0xB0) {
-                                       if (MF_DBGLEVEL >= 2) Dbprintf("RECV 0x%02x transfer block %d (%02x)",receivedCmd[0],receivedCmd[1],receivedCmd[1]);
+                                       if (MF_DBGLEVEL >= 4) Dbprintf("RECV 0x%02x transfer block %d (%02x)",receivedCmd[0],receivedCmd[1],receivedCmd[1]);
                                        if (emlSetValBl(cardINTREG, cardINTBLOCK, receivedCmd[1]))
                                                EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
                                        else
@@ -2593,11 +2590,12 @@ void Mifare1ksim(uint8_t flags, uint8_t exitAfterNReads, uint8_t arg2, uint8_t *
                //May just aswell send the collected ar_nr in the response aswell
                cmd_send(CMD_ACK,CMD_SIMULATE_MIFARE_CARD,0,0,&ar_nr_responses,ar_nr_collected*4*4);
        }
+
        if(flags & FLAG_NR_AR_ATTACK)
        {
                if(ar_nr_collected > 1) {
                        Dbprintf("Collected two pairs of AR/NR which can be used to extract keys from reader:");
-                       Dbprintf("../tools/mfkey/mfkey32 %08x %08x %08x %08x",
+                       Dbprintf("../tools/mfkey/mfkey32 %08x %08x %08x %08x %08x %08x",
                                         ar_nr_responses[0], // UID
                                        ar_nr_responses[1], //NT
                                        ar_nr_responses[2], //AR1
@@ -2608,7 +2606,7 @@ void Mifare1ksim(uint8_t flags, uint8_t exitAfterNReads, uint8_t arg2, uint8_t *
                } else {
                        Dbprintf("Failed to obtain two AR/NR pairs!");
                        if(ar_nr_collected >0) {
-                               Dbprintf("Only got these: UID=%08d, nonce=%08d, AR1=%08d, NR1=%08d",
+                               Dbprintf("Only got these: UID=%08x, nonce=%08x, AR1=%08x, NR1=%08x",
                                                ar_nr_responses[0], // UID
                                                ar_nr_responses[1], //NT
                                                ar_nr_responses[2], //AR1
@@ -2634,7 +2632,8 @@ void RAMFUNC SniffMifare(uint8_t param) {
        // C(red) A(yellow) B(green)
        LEDsoff();
        // init trace buffer
-    iso14a_clear_trace();
+       iso14a_clear_trace();
+       iso14a_set_tracing(TRUE);
 
        // The command (reader -> tag) that we're receiving.
        // The length of a received command will in most cases be no more than 18 bytes.
@@ -2762,7 +2761,7 @@ void RAMFUNC SniffMifare(uint8_t param) {
                previous_data = *data;
                sniffCounter++;
                data++;
-               if(data > dmaBuf + DMA_BUFFER_SIZE) {
+               if(data == dmaBuf + DMA_BUFFER_SIZE) {
                        data = dmaBuf;
                }
 
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