X-Git-Url: http://cvs.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/blobdiff_plain/c89274cc60bf433cbf1091d9a6ca0b813ea9b224..5cfd18ac1eac1e6a2293415ddcaa2c9b826ac6d8:/armsrc/iso14443a.c diff --git a/armsrc/iso14443a.c b/armsrc/iso14443a.c index f81a1a99..27574dad 100644 --- a/armsrc/iso14443a.c +++ b/armsrc/iso14443a.c @@ -213,6 +213,12 @@ void AppendCrc14443a(uint8_t* data, int len) ComputeCrc14443(CRC_14443_A,data,len,data+len,data+len+1); } +void AppendCrc14443b(uint8_t* data, int len) +{ + ComputeCrc14443(CRC_14443_B,data,len,data+len,data+len+1); +} + + //============================================================================= // ISO 14443 Type A - Miller decoder //============================================================================= @@ -232,13 +238,17 @@ void AppendCrc14443a(uint8_t* data, int len) static tUart Uart; // Lookup-Table to decide if 4 raw bits are a modulation. -// We accept two or three consecutive "0" in any position with the rest "1" +// We accept the following: +// 0001 - a 3 tick wide pause +// 0011 - a 2 tick wide pause, or a three tick wide pause shifted left +// 0111 - a 2 tick wide pause shifted left +// 1001 - a 2 tick wide pause shifted right const bool Mod_Miller_LUT[] = { - TRUE, TRUE, FALSE, TRUE, FALSE, FALSE, FALSE, FALSE, - TRUE, TRUE, FALSE, FALSE, TRUE, FALSE, FALSE, FALSE + FALSE, TRUE, FALSE, TRUE, FALSE, FALSE, FALSE, TRUE, + FALSE, TRUE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE }; -#define IsMillerModulationNibble1(b) (Mod_Miller_LUT[(b & 0x00F0) >> 4]) -#define IsMillerModulationNibble2(b) (Mod_Miller_LUT[(b & 0x000F)]) +#define IsMillerModulationNibble1(b) (Mod_Miller_LUT[(b & 0x000000F0) >> 4]) +#define IsMillerModulationNibble2(b) (Mod_Miller_LUT[(b & 0x0000000F)]) void UartReset() { @@ -248,8 +258,6 @@ void UartReset() Uart.parityLen = 0; // number of decoded parity bytes Uart.shiftReg = 0; // shiftreg to hold decoded data bits Uart.parityBits = 0; // holds 8 parity bits - Uart.twoBits = 0x0000; // buffer for 2 Bits - Uart.highCnt = 0; Uart.startTime = 0; Uart.endTime = 0; } @@ -258,6 +266,7 @@ void UartInit(uint8_t *data, uint8_t *parity) { Uart.output = data; Uart.parity = parity; + Uart.fourBits = 0x00000000; // clear the buffer for 4 Bits UartReset(); } @@ -265,40 +274,37 @@ void UartInit(uint8_t *data, uint8_t *parity) static RAMFUNC bool MillerDecoding(uint8_t bit, uint32_t non_real_time) { - Uart.twoBits = (Uart.twoBits << 8) | bit; + Uart.fourBits = (Uart.fourBits << 8) | bit; if (Uart.state == STATE_UNSYNCD) { // not yet synced - if (Uart.highCnt < 2) { // wait for a stable unmodulated signal - if (Uart.twoBits == 0xffff) { - Uart.highCnt++; - } else { - Uart.highCnt = 0; - } - } else { - Uart.syncBit = 0xFFFF; // not set - // we look for a ...1111111100x11111xxxxxx pattern (the start bit) - if ((Uart.twoBits & 0xDF00) == 0x1F00) Uart.syncBit = 8; // mask is 11x11111 xxxxxxxx, - // check for 00x11111 xxxxxxxx - else if ((Uart.twoBits & 0xEF80) == 0x8F80) Uart.syncBit = 7; // both masks shifted right one bit, left padded with '1' - else if ((Uart.twoBits & 0xF7C0) == 0xC7C0) Uart.syncBit = 6; // ... - else if ((Uart.twoBits & 0xFBE0) == 0xE3E0) Uart.syncBit = 5; - else if ((Uart.twoBits & 0xFDF0) == 0xF1F0) Uart.syncBit = 4; - else if ((Uart.twoBits & 0xFEF8) == 0xF8F8) Uart.syncBit = 3; - else if ((Uart.twoBits & 0xFF7C) == 0xFC7C) Uart.syncBit = 2; - else if ((Uart.twoBits & 0xFFBE) == 0xFE3E) Uart.syncBit = 1; - if (Uart.syncBit != 0xFFFF) { // found a sync bit - Uart.startTime = non_real_time?non_real_time:(GetCountSspClk() & 0xfffffff8); - Uart.startTime -= Uart.syncBit; - Uart.endTime = Uart.startTime; - Uart.state = STATE_START_OF_COMMUNICATION; - } + Uart.syncBit = 9999; // not set + // The start bit is one ore more Sequence Y followed by a Sequence Z (... 11111111 00x11111). We need to distinguish from + // Sequence X followed by Sequence Y followed by Sequence Z (111100x1 11111111 00x11111) + // we therefore look for a ...xx11111111111100x11111xxxxxx... pattern + // (12 '1's followed by 2 '0's, eventually followed by another '0', followed by 5 '1's) + #define ISO14443A_STARTBIT_MASK 0x07FFEF80 // mask is 00000111 11111111 11101111 10000000 + #define ISO14443A_STARTBIT_PATTERN 0x07FF8F80 // pattern is 00000111 11111111 10001111 10000000 + if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 0)) == ISO14443A_STARTBIT_PATTERN >> 0) Uart.syncBit = 7; + else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 1)) == ISO14443A_STARTBIT_PATTERN >> 1) Uart.syncBit = 6; + else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 2)) == ISO14443A_STARTBIT_PATTERN >> 2) Uart.syncBit = 5; + else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 3)) == ISO14443A_STARTBIT_PATTERN >> 3) Uart.syncBit = 4; + else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 4)) == ISO14443A_STARTBIT_PATTERN >> 4) Uart.syncBit = 3; + else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 5)) == ISO14443A_STARTBIT_PATTERN >> 5) Uart.syncBit = 2; + else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 6)) == ISO14443A_STARTBIT_PATTERN >> 6) Uart.syncBit = 1; + else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 7)) == ISO14443A_STARTBIT_PATTERN >> 7) Uart.syncBit = 0; + + if (Uart.syncBit != 9999) { // found a sync bit + Uart.startTime = non_real_time?non_real_time:(GetCountSspClk() & 0xfffffff8); + Uart.startTime -= Uart.syncBit; + Uart.endTime = Uart.startTime; + Uart.state = STATE_START_OF_COMMUNICATION; } } else { - if (IsMillerModulationNibble1(Uart.twoBits >> Uart.syncBit)) { - if (IsMillerModulationNibble2(Uart.twoBits >> Uart.syncBit)) { // Modulation in both halves - error + if (IsMillerModulationNibble1(Uart.fourBits >> Uart.syncBit)) { + if (IsMillerModulationNibble2(Uart.fourBits >> Uart.syncBit)) { // Modulation in both halves - error UartReset(); } else { // Modulation in first half = Sequence Z = logic "0" if (Uart.state == STATE_MILLER_X) { // error - must not follow after X @@ -322,7 +328,7 @@ static RAMFUNC bool MillerDecoding(uint8_t bit, uint32_t non_real_time) } } } else { - if (IsMillerModulationNibble2(Uart.twoBits >> Uart.syncBit)) { // Modulation second half = Sequence X = logic "1" + if (IsMillerModulationNibble2(Uart.fourBits >> Uart.syncBit)) { // Modulation second half = Sequence X = logic "1" Uart.bitCount++; Uart.shiftReg = (Uart.shiftReg >> 1) | 0x100; // add a 1 to the shiftreg Uart.state = STATE_MILLER_X; @@ -358,12 +364,10 @@ static RAMFUNC bool MillerDecoding(uint8_t bit, uint32_t non_real_time) return TRUE; // we are finished with decoding the raw data sequence } else { UartReset(); // Nothing received - start over - Uart.highCnt = 1; } } if (Uart.state == STATE_START_OF_COMMUNICATION) { // error - must not follow directly after SOC UartReset(); - Uart.highCnt = 1; } else { // a logic "0" Uart.bitCount++; Uart.shiftReg = (Uart.shiftReg >> 1); // add a 0 to the shiftreg @@ -680,6 +684,9 @@ void RAMFUNC SnoopIso14443a(uint8_t param) { // And ready to receive another response. DemodReset(); + // And reset the Miller decoder including itS (now outdated) input buffer + UartInit(receivedCmd, receivedCmdPar); + LED_C_OFF(); } TagIsActive = (Demod.state != DEMOD_UNSYNCD); @@ -1336,7 +1343,7 @@ void CodeIso14443aBitsAsReaderPar(const uint8_t *cmd, uint16_t bits, const uint8 } // Only transmit parity bit if we transmitted a complete byte - if (j == 8) { + if (j == 8 && parity != NULL) { // Get the parity bit if (parity[i>>3] & (0x80 >> (i&0x0007))) { // Sequence X @@ -1630,6 +1637,7 @@ static int GetIso14443aAnswerFromTag(uint8_t *receivedResponse, uint8_t *receive } } + void ReaderTransmitBitsPar(uint8_t* frame, uint16_t bits, uint8_t *par, uint32_t *timing) { CodeIso14443aBitsAsReaderPar(frame, bits, par); @@ -1645,11 +1653,13 @@ void ReaderTransmitBitsPar(uint8_t* frame, uint16_t bits, uint8_t *par, uint32_t } } + void ReaderTransmitPar(uint8_t* frame, uint16_t len, uint8_t *par, uint32_t *timing) { ReaderTransmitBitsPar(frame, len*8, par, timing); } + void ReaderTransmitBits(uint8_t* frame, uint16_t len, uint32_t *timing) { // Generate parity and redirect @@ -1658,6 +1668,7 @@ void ReaderTransmitBits(uint8_t* frame, uint16_t len, uint32_t *timing) ReaderTransmitBitsPar(frame, len, par, timing); } + void ReaderTransmit(uint8_t* frame, uint16_t len, uint32_t *timing) { // Generate parity and redirect @@ -1718,6 +1729,11 @@ int iso14443a_select_card(byte_t *uid_ptr, iso14a_card_select_t *p_hi14a_card, u memset(uid_ptr,0,10); } + // check for proprietary anticollision: + if ((resp[0] & 0x1F) == 0) { + return 3; + } + // OK we will select at least at cascade 1, lets see if first byte of UID was 0x88 in // which case we need to make a cascade 2 request and select - this is a long UID // While the UID is not complete, the 3nd bit (from the right) is set in the SAK. @@ -1926,15 +1942,38 @@ void ReaderIso14443a(UsbCommand *c) if(param & ISO14A_RAW) { if(param & ISO14A_APPEND_CRC) { - AppendCrc14443a(cmd,len); + if(param & ISO14A_TOPAZMODE) { + AppendCrc14443b(cmd,len); + } else { + AppendCrc14443a(cmd,len); + } len += 2; if (lenbits) lenbits += 16; } - if(lenbits>0) { - GetParity(cmd, lenbits/8, par); - ReaderTransmitBitsPar(cmd, lenbits, par, NULL); - } else { - ReaderTransmit(cmd,len, NULL); + if(lenbits>0) { // want to send a specific number of bits (e.g. short commands) + if(param & ISO14A_TOPAZMODE) { + int bits_to_send = lenbits; + uint16_t i = 0; + ReaderTransmitBitsPar(&cmd[i++], MIN(bits_to_send, 7), NULL, NULL); // first byte is always short (7bits) and no parity + bits_to_send -= 7; + while (bits_to_send > 0) { + ReaderTransmitBitsPar(&cmd[i++], MIN(bits_to_send, 8), NULL, NULL); // following bytes are 8 bit and no parity + bits_to_send -= 8; + } + } else { + GetParity(cmd, lenbits/8, par); + ReaderTransmitBitsPar(cmd, lenbits, par, NULL); // bytes are 8 bit with odd parity + } + } else { // want to send complete bytes only + if(param & ISO14A_TOPAZMODE) { + uint16_t i = 0; + ReaderTransmitBitsPar(&cmd[i++], 7, NULL, NULL); // first byte: 7 bits, no paritiy + while (i < len) { + ReaderTransmitBitsPar(&cmd[i++], 8, NULL, NULL); // following bytes: 8 bits, no paritiy + } + } else { + ReaderTransmit(cmd,len, NULL); // 8 bits, odd parity + } } arg0 = ReaderReceive(buf, par); cmd_send(CMD_ACK,arg0,0,0,buf,sizeof(buf)); @@ -2016,19 +2055,20 @@ void ReaderMifare(bool first_try) byte_t par_list[8] = {0x00}; byte_t ks_list[8] = {0x00}; + #define PRNG_SEQUENCE_LENGTH (1 << 16); static uint32_t sync_time; - static uint32_t sync_cycles; + static int32_t sync_cycles; int catch_up_cycles = 0; int last_catch_up = 0; + uint16_t elapsed_prng_sequences; uint16_t consecutive_resyncs = 0; int isOK = 0; if (first_try) { mf_nr_ar3 = 0; sync_time = GetCountSspClk() & 0xfffffff8; - sync_cycles = 65536; // theory: Mifare Classic's random generator repeats every 2^16 cycles (and so do the nonces). + sync_cycles = PRNG_SEQUENCE_LENGTH; // theory: Mifare Classic's random generator repeats every 2^16 cycles (and so do the tag nonces). nt_attacked = 0; - nt = 0; par[0] = 0; } else { @@ -2043,8 +2083,17 @@ void ReaderMifare(bool first_try) LED_C_OFF(); - #define DARKSIDE_MAX_TRIES 32 // number of tries to sync on PRNG cycle. Then give up. - uint16_t unsuccessfull_tries = 0; + #define MAX_UNEXPECTED_RANDOM 4 // maximum number of unexpected (i.e. real) random numbers when trying to sync. Then give up. + #define MAX_SYNC_TRIES 32 + #define NUM_DEBUG_INFOS 8 // per strategy + #define MAX_STRATEGY 3 + uint16_t unexpected_random = 0; + uint16_t sync_tries = 0; + int16_t debug_info_nr = -1; + uint16_t strategy = 0; + int32_t debug_info[MAX_STRATEGY][NUM_DEBUG_INFOS]; + uint32_t select_time; + uint32_t halt_time; for(uint16_t i = 0; TRUE; i++) { @@ -2057,21 +2106,60 @@ void ReaderMifare(bool first_try) break; } + if (strategy == 2) { + // test with additional hlt command + halt_time = 0; + int len = mifare_sendcmd_short(NULL, false, 0x50, 0x00, receivedAnswer, receivedAnswerPar, &halt_time); + if (len && MF_DBGLEVEL >= 3) { + Dbprintf("Unexpected response of %d bytes to hlt command (additional debugging).", len); + } + } + + if (strategy == 3) { + // test with FPGA power off/on + FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); + SpinDelay(200); + iso14443a_setup(FPGA_HF_ISO14443A_READER_MOD); + SpinDelay(100); + } + if(!iso14443a_select_card(uid, NULL, &cuid)) { if (MF_DBGLEVEL >= 1) Dbprintf("Mifare: Can't select card"); continue; } + select_time = GetCountSspClk(); - sync_time = (sync_time & 0xfffffff8) + sync_cycles + catch_up_cycles; - catch_up_cycles = 0; + elapsed_prng_sequences = 1; + if (debug_info_nr == -1) { + sync_time = (sync_time & 0xfffffff8) + sync_cycles + catch_up_cycles; + catch_up_cycles = 0; - // if we missed the sync time already, advance to the next nonce repeat - while(GetCountSspClk() > sync_time) { - sync_time = (sync_time & 0xfffffff8) + sync_cycles; - } + // if we missed the sync time already, advance to the next nonce repeat + while(GetCountSspClk() > sync_time) { + elapsed_prng_sequences++; + sync_time = (sync_time & 0xfffffff8) + sync_cycles; + } - // Transmit MIFARE_CLASSIC_AUTH at synctime. Should result in returning the same tag nonce (== nt_attacked) - ReaderTransmit(mf_auth, sizeof(mf_auth), &sync_time); + // Transmit MIFARE_CLASSIC_AUTH at synctime. Should result in returning the same tag nonce (== nt_attacked) + ReaderTransmit(mf_auth, sizeof(mf_auth), &sync_time); + } else { + // collect some information on tag nonces for debugging: + #define DEBUG_FIXED_SYNC_CYCLES PRNG_SEQUENCE_LENGTH + if (strategy == 0) { + // nonce distances at fixed time after card select: + sync_time = select_time + DEBUG_FIXED_SYNC_CYCLES; + } else if (strategy == 1) { + // nonce distances at fixed time between authentications: + sync_time = sync_time + DEBUG_FIXED_SYNC_CYCLES; + } else if (strategy == 2) { + // nonce distances at fixed time after halt: + sync_time = halt_time + DEBUG_FIXED_SYNC_CYCLES; + } else { + // nonce_distances at fixed time after power on + sync_time = DEBUG_FIXED_SYNC_CYCLES; + } + ReaderTransmit(mf_auth, sizeof(mf_auth), &sync_time); + } // Receive the (4 Byte) "random" nonce if (!ReaderReceive(receivedAnswer, receivedAnswerPar)) { @@ -2089,19 +2177,37 @@ void ReaderMifare(bool first_try) int nt_distance = dist_nt(previous_nt, nt); if (nt_distance == 0) { nt_attacked = nt; - } - else { + } else { if (nt_distance == -99999) { // invalid nonce received - unsuccessfull_tries++; - if (!nt_attacked && unsuccessfull_tries > DARKSIDE_MAX_TRIES) { + unexpected_random++; + if (unexpected_random > MAX_UNEXPECTED_RANDOM) { isOK = -3; // Card has an unpredictable PRNG. Give up break; } else { continue; // continue trying... } } - sync_cycles = (sync_cycles - nt_distance); - if (MF_DBGLEVEL >= 3) Dbprintf("calibrating in cycle %d. nt_distance=%d, Sync_cycles: %d\n", i, nt_distance, sync_cycles); + if (++sync_tries > MAX_SYNC_TRIES) { + if (strategy > MAX_STRATEGY || MF_DBGLEVEL < 3) { + isOK = -4; // Card's PRNG runs at an unexpected frequency or resets unexpectedly + break; + } else { // continue for a while, just to collect some debug info + debug_info[strategy][debug_info_nr] = nt_distance; + debug_info_nr++; + if (debug_info_nr == NUM_DEBUG_INFOS) { + strategy++; + debug_info_nr = 0; + } + continue; + } + } + sync_cycles = (sync_cycles - nt_distance/elapsed_prng_sequences); + if (sync_cycles <= 0) { + sync_cycles += PRNG_SEQUENCE_LENGTH; + } + if (MF_DBGLEVEL >= 3) { + Dbprintf("calibrating in cycle %d. nt_distance=%d, elapsed_prng_sequences=%d, new sync_cycles: %d\n", i, nt_distance, elapsed_prng_sequences, sync_cycles); + } continue; } } @@ -2112,6 +2218,7 @@ void ReaderMifare(bool first_try) catch_up_cycles = 0; continue; } + catch_up_cycles /= elapsed_prng_sequences; if (catch_up_cycles == last_catch_up) { consecutive_resyncs++; } @@ -2125,6 +2232,9 @@ void ReaderMifare(bool first_try) else { sync_cycles = sync_cycles + catch_up_cycles; if (MF_DBGLEVEL >= 3) Dbprintf("Lost sync in cycle %d for the fourth time consecutively (nt_distance = %d). Adjusting sync_cycles to %d.\n", i, -catch_up_cycles, sync_cycles); + last_catch_up = 0; + catch_up_cycles = 0; + consecutive_resyncs = 0; } continue; } @@ -2132,12 +2242,10 @@ void ReaderMifare(bool first_try) consecutive_resyncs = 0; // Receive answer. This will be a 4 Bit NACK when the 8 parity bits are OK after decoding - if (ReaderReceive(receivedAnswer, receivedAnswerPar)) - { + if (ReaderReceive(receivedAnswer, receivedAnswerPar)) { catch_up_cycles = 8; // the PRNG is delayed by 8 cycles due to the NAC (4Bits = 0x05 encrypted) transfer - if (nt_diff == 0) - { + if (nt_diff == 0) { par_low = par[0] & 0xE0; // there is no need to check all parities for other nt_diff. Parity Bits for mf_nr_ar[0..2] won't change } @@ -2172,6 +2280,16 @@ void ReaderMifare(bool first_try) mf_nr_ar[3] &= 0x1F; + + if (isOK == -4) { + if (MF_DBGLEVEL >= 3) { + for (uint16_t i = 0; i <= MAX_STRATEGY; i++) { + for(uint16_t j = 0; j < NUM_DEBUG_INFOS; j++) { + Dbprintf("collected debug info[%d][%d] = %d", i, j, debug_info[i][j]); + } + } + } + } byte_t buf[28]; memcpy(buf + 0, uid, 4); @@ -2814,7 +2932,7 @@ void RAMFUNC SniffMifare(uint8_t param) { if (MfSniffLogic(receivedCmd, Uart.len, Uart.parity, Uart.bitCount, TRUE)) break; /* And ready to receive another command. */ - UartReset(); + UartInit(receivedCmd, receivedCmdPar); /* And also reset the demod code */ DemodReset(); @@ -2831,6 +2949,8 @@ void RAMFUNC SniffMifare(uint8_t param) { // And ready to receive another response. DemodReset(); + // And reset the Miller decoder including its (now outdated) input buffer + UartInit(receivedCmd, receivedCmdPar); } TagIsActive = (Demod.state != DEMOD_UNSYNCD); }