//----------------------------------------------------------------------------- // Merlok - June 2011, 2012 // Gerhard de Koning Gans - May 2008 // Hagen Fritsch - June 2010 // // This code is licensed to you under the terms of the GNU GPL, version 2 or, // at your option, any later version. See the LICENSE.txt file for the text of // the license. //----------------------------------------------------------------------------- // Routines to support ISO 14443 type A. //----------------------------------------------------------------------------- #include "proxmark3.h" #include "apps.h" #include "util.h" #include "string.h" #include "cmd.h" #include "iso14443crc.h" #include "iso14443a.h" #include "crapto1.h" #include "mifareutil.h" static uint32_t iso14a_timeout; int rsamples = 0; int tracing = TRUE; uint8_t trigger = 0; // the block number for the ISO14443-4 PCB static uint8_t iso14_pcb_blocknum = 0; // // ISO14443 timing: // // minimum time between the start bits of consecutive transfers from reader to tag: 7000 carrier (13.56Mhz) cycles #define REQUEST_GUARD_TIME (7000/16 + 1) // minimum time between last modulation of tag and next start bit from reader to tag: 1172 carrier cycles #define FRAME_DELAY_TIME_PICC_TO_PCD (1172/16 + 1) // bool LastCommandWasRequest = FALSE; // // 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 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 + 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 // 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 // 1 tick to assign mod_sig_coil #define DELAY_ARM2AIR_AS_READER (4*16 + 8*16 + 8 + 8 + 1) // When the PM acts as tag and is receiving it takes // 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 // 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 (2 + 3 + 8 + 8 + 7*16 + 8 + 4*16 - 8*16) // The FPGA will report its internal sending delay in uint16_t FpgaSendQueueDelay; // the 5 first bits are the number of bits buffered in mod_sig_buf // the last three bits are the remaining ticks/2 after the mod_sig_buf shift #define DELAY_FPGA_QUEUE (FpgaSendQueueDelay<<1) // When the PM acts as tag and is sending, it takes // 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 (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 // 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 + 14 + 8) // 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 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 (2 + 3 + 8) //variables used for timing purposes: //these are in ssp_clk cycles: static uint32_t NextTransferTime; static uint32_t LastTimeProxToAirStart; static uint32_t LastProxToAirDuration; // CARD TO READER - manchester // Sequence D: 11110000 modulation with subcarrier during first half // Sequence E: 00001111 modulation with subcarrier during second half // Sequence F: 00000000 no modulation with subcarrier // READER TO CARD - miller // Sequence X: 00001100 drop after half a period // Sequence Y: 00000000 no drop // Sequence Z: 11000000 drop at start #define SEC_D 0xf0 #define SEC_E 0x0f #define SEC_F 0x00 #define SEC_X 0x0c #define SEC_Y 0x00 #define SEC_Z 0xc0 const uint8_t OddByteParity[256] = { 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1, 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0, 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1, 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0, 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1, 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0, 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1, 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0, 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1, 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0, 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1 }; void iso14a_set_trigger(bool enable) { trigger = enable; } void iso14a_clear_trace() { uint8_t *trace = BigBuf_get_addr(); memset(trace, 0x44, TRACE_SIZE); traceLen = 0; } void iso14a_set_tracing(bool enable) { tracing = enable; } void iso14a_set_timeout(uint32_t timeout) { iso14a_timeout = timeout; } //----------------------------------------------------------------------------- // Generate the parity value for a byte sequence // //----------------------------------------------------------------------------- byte_t oddparity (const byte_t bt) { return OddByteParity[bt]; } void GetParity(const uint8_t *pbtCmd, uint16_t iLen, uint8_t *par) { uint16_t paritybit_cnt = 0; uint16_t paritybyte_cnt = 0; uint8_t parityBits = 0; for (uint16_t i = 0; i < iLen; i++) { // Generate the parity bits parityBits |= ((OddByteParity[pbtCmd[i]]) << (7-paritybit_cnt)); if (paritybit_cnt == 7) { par[paritybyte_cnt] = parityBits; // save 8 Bits parity parityBits = 0; // and advance to next Parity Byte paritybyte_cnt++; paritybit_cnt = 0; } else { paritybit_cnt++; } } // save remaining parity bits par[paritybyte_cnt] = parityBits; } void AppendCrc14443a(uint8_t* data, int len) { ComputeCrc14443(CRC_14443_A,data,len,data+len,data+len+1); } // The function LogTrace() is also used by the iClass implementation in iClass.c bool RAMFUNC LogTrace(const uint8_t *btBytes, uint16_t iLen, uint32_t timestamp_start, uint32_t timestamp_end, uint8_t *parity, bool readerToTag) { if (!tracing) return FALSE; uint8_t *trace = BigBuf_get_addr(); uint16_t num_paritybytes = (iLen-1)/8 + 1; // number of valid paritybytes in *parity uint16_t duration = timestamp_end - timestamp_start; // Return when trace is full if (traceLen + sizeof(iLen) + sizeof(timestamp_start) + sizeof(duration) + num_paritybytes + iLen >= TRACE_SIZE) { tracing = FALSE; // don't trace any more return FALSE; } // Traceformat: // 32 bits timestamp (little endian) // 16 bits duration (little endian) // 16 bits data length (little endian, Highest Bit used as readerToTag flag) // y Bytes data // x Bytes parity (one byte per 8 bytes data) // timestamp (start) trace[traceLen++] = ((timestamp_start >> 0) & 0xff); trace[traceLen++] = ((timestamp_start >> 8) & 0xff); trace[traceLen++] = ((timestamp_start >> 16) & 0xff); trace[traceLen++] = ((timestamp_start >> 24) & 0xff); // duration trace[traceLen++] = ((duration >> 0) & 0xff); trace[traceLen++] = ((duration >> 8) & 0xff); // data length trace[traceLen++] = ((iLen >> 0) & 0xff); trace[traceLen++] = ((iLen >> 8) & 0xff); // readerToTag flag if (!readerToTag) { trace[traceLen - 1] |= 0x80; } // data bytes if (btBytes != NULL && iLen != 0) { memcpy(trace + traceLen, btBytes, iLen); } traceLen += iLen; // parity bytes if (parity != NULL && iLen != 0) { memcpy(trace + traceLen, parity, num_paritybytes); } traceLen += num_paritybytes; return TRUE; } //============================================================================= // ISO 14443 Type A - Miller decoder //============================================================================= // Basics: // This decoder is used when the PM3 acts as a tag. // The reader will generate "pauses" by temporarily switching of the field. // At the PM3 antenna we will therefore measure a modulated antenna voltage. // The FPGA does a comparison with a threshold and would deliver e.g.: // ........ 1 1 1 1 1 1 0 0 1 1 1 1 1 1 1 1 1 1 0 0 1 1 1 1 1 1 1 1 1 1 ....... // The Miller decoder needs to identify the following sequences: // 2 (or 3) ticks pause followed by 6 (or 5) ticks unmodulated: pause at beginning - Sequence Z ("start of communication" or a "0") // 8 ticks without a modulation: no pause - Sequence Y (a "0" or "end of communication" or "no information") // 4 ticks unmodulated followed by 2 (or 3) ticks pause: pause in second half - Sequence X (a "1") // Note 1: the bitstream may start at any time. We therefore need to sync. // Note 2: the interpretation of Sequence Y and Z depends on the preceding sequence. //----------------------------------------------------------------------------- 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" const bool Mod_Miller_LUT[] = { TRUE, TRUE, FALSE, TRUE, FALSE, FALSE, FALSE, FALSE, TRUE, TRUE, FALSE, FALSE, TRUE, FALSE, FALSE, FALSE }; #define IsMillerModulationNibble1(b) (Mod_Miller_LUT[(b & 0x00F0) >> 4]) #define IsMillerModulationNibble2(b) (Mod_Miller_LUT[(b & 0x000F)]) void UartReset() { Uart.state = STATE_UNSYNCD; Uart.bitCount = 0; Uart.len = 0; // number of decoded data bytes 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; } void UartInit(uint8_t *data, uint8_t *parity) { Uart.output = data; Uart.parity = parity; UartReset(); } // 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) { Uart.twoBits = (Uart.twoBits << 8) | bit; if (Uart.state == STATE_UNSYNCD) { // not yet synced if (Uart.highCnt < 7) { // wait for a stable unmodulated signal if (Uart.twoBits == 0xffff) { Uart.highCnt++; } else { Uart.highCnt = 0; } } else { Uart.syncBit = 0xFFFF; // not set // look for 00xx1111 (the start bit) if ((Uart.twoBits & 0x6780) == 0x0780) Uart.syncBit = 7; else if ((Uart.twoBits & 0x33C0) == 0x03C0) Uart.syncBit = 6; else if ((Uart.twoBits & 0x19E0) == 0x01E0) Uart.syncBit = 5; else if ((Uart.twoBits & 0x0CF0) == 0x00F0) Uart.syncBit = 4; else if ((Uart.twoBits & 0x0678) == 0x0078) Uart.syncBit = 3; else if ((Uart.twoBits & 0x033C) == 0x003C) Uart.syncBit = 2; else if ((Uart.twoBits & 0x019E) == 0x001E) Uart.syncBit = 1; else if ((Uart.twoBits & 0x00CF) == 0x000F) Uart.syncBit = 0; if (Uart.syncBit != 0xFFFF) { 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 UartReset(); Uart.highCnt = 6; } else { // Modulation in first half = Sequence Z = logic "0" if (Uart.state == STATE_MILLER_X) { // error - must not follow after X UartReset(); Uart.highCnt = 6; } else { Uart.bitCount++; Uart.shiftReg = (Uart.shiftReg >> 1); // add a 0 to the shiftreg Uart.state = STATE_MILLER_Z; Uart.endTime = Uart.startTime + 8*(9*Uart.len + Uart.bitCount + 1) - 6; if(Uart.bitCount >= 9) { // if we decoded a full byte (including parity) Uart.output[Uart.len++] = (Uart.shiftReg & 0xff); Uart.parityBits <<= 1; // make room for the parity bit Uart.parityBits |= ((Uart.shiftReg >> 8) & 0x01); // store parity bit Uart.bitCount = 0; Uart.shiftReg = 0; if((Uart.len&0x0007) == 0) { // every 8 data bytes Uart.parity[Uart.parityLen++] = Uart.parityBits; // store 8 parity bits Uart.parityBits = 0; } } } } } else { if (IsMillerModulationNibble2(Uart.twoBits >> 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; Uart.endTime = Uart.startTime + 8*(9*Uart.len + Uart.bitCount + 1) - 2; if(Uart.bitCount >= 9) { // if we decoded a full byte (including parity) Uart.output[Uart.len++] = (Uart.shiftReg & 0xff); Uart.parityBits <<= 1; // make room for the new parity bit Uart.parityBits |= ((Uart.shiftReg >> 8) & 0x01); // store parity bit Uart.bitCount = 0; Uart.shiftReg = 0; if ((Uart.len&0x0007) == 0) { // every 8 data bytes Uart.parity[Uart.parityLen++] = Uart.parityBits; // store 8 parity bits Uart.parityBits = 0; } } } else { // no modulation in both halves - Sequence Y if (Uart.state == STATE_MILLER_Z || Uart.state == STATE_MILLER_Y) { // Y after logic "0" - End of Communication Uart.state = STATE_UNSYNCD; Uart.bitCount--; // last "0" was part of EOC sequence Uart.shiftReg <<= 1; // drop it if(Uart.bitCount > 0) { // if we decoded some bits Uart.shiftReg >>= (9 - Uart.bitCount); // right align them Uart.output[Uart.len++] = (Uart.shiftReg & 0xff); // add last byte to the output Uart.parityBits <<= 1; // add a (void) parity bit Uart.parityBits <<= (8 - (Uart.len&0x0007)); // left align parity bits Uart.parity[Uart.parityLen++] = Uart.parityBits; // and store it return TRUE; } else if (Uart.len & 0x0007) { // there are some parity bits to store Uart.parityBits <<= (8 - (Uart.len&0x0007)); // left align remaining parity bits Uart.parity[Uart.parityLen++] = Uart.parityBits; // and store them } if (Uart.len) { return TRUE; // we are finished with decoding the raw data sequence } else { UartReset(); // Nothing receiver - start over } } if (Uart.state == STATE_START_OF_COMMUNICATION) { // error - must not follow directly after SOC UartReset(); Uart.highCnt = 6; } else { // a logic "0" Uart.bitCount++; Uart.shiftReg = (Uart.shiftReg >> 1); // add a 0 to the shiftreg Uart.state = STATE_MILLER_Y; if(Uart.bitCount >= 9) { // if we decoded a full byte (including parity) Uart.output[Uart.len++] = (Uart.shiftReg & 0xff); Uart.parityBits <<= 1; // make room for the parity bit Uart.parityBits |= ((Uart.shiftReg >> 8) & 0x01); // store parity bit Uart.bitCount = 0; Uart.shiftReg = 0; if ((Uart.len&0x0007) == 0) { // every 8 data bytes Uart.parity[Uart.parityLen++] = Uart.parityBits; // store 8 parity bits Uart.parityBits = 0; } } } } } } return FALSE; // not finished yet, need more data } //============================================================================= // ISO 14443 Type A - Manchester decoder //============================================================================= // Basics: // This decoder is used when the PM3 acts as a reader. // The tag will modulate the reader field by asserting different loads to it. As a consequence, the voltage // at the reader antenna will be modulated as well. The FPGA detects the modulation for us and would deliver e.g. the following: // ........ 0 0 1 1 1 1 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 ....... // The Manchester decoder needs to identify the following sequences: // 4 ticks modulated followed by 4 ticks unmodulated: Sequence D = 1 (also used as "start of communication") // 4 ticks unmodulated followed by 4 ticks modulated: Sequence E = 0 // 8 ticks unmodulated: Sequence F = end of communication // 8 ticks modulated: A collision. Save the collision position and treat as Sequence D // Note 1: the bitstream may start at any time. We therefore need to sync. // Note 2: parameter offset is used to determine the position of the parity bits (required for the anticollision command only) static tDemod Demod; // Lookup-Table to decide if 4 raw bits are a modulation. // 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, TRUE, FALSE, TRUE, TRUE, TRUE }; #define IsManchesterModulationNibble1(b) (Mod_Manchester_LUT[(b & 0x00F0) >> 4]) #define IsManchesterModulationNibble2(b) (Mod_Manchester_LUT[(b & 0x000F)]) void DemodReset() { Demod.state = DEMOD_UNSYNCD; Demod.len = 0; // number of decoded data bytes Demod.parityLen = 0; Demod.shiftReg = 0; // shiftreg to hold decoded data bits Demod.parityBits = 0; // Demod.collisionPos = 0; // Position of collision bit Demod.twoBits = 0xffff; // buffer for 2 Bits Demod.highCnt = 0; Demod.startTime = 0; Demod.endTime = 0; } void DemodInit(uint8_t *data, uint8_t *parity) { Demod.output = data; Demod.parity = parity; DemodReset(); } // use parameter non_real_time to provide a timestamp. Set to 0 if the decoder should measure real time static RAMFUNC int ManchesterDecoding(uint8_t bit, uint16_t offset, uint32_t non_real_time) { Demod.twoBits = (Demod.twoBits << 8) | bit; if (Demod.state == DEMOD_UNSYNCD) { if (Demod.highCnt < 2) { // wait for a stable unmodulated signal if (Demod.twoBits == 0x0000) { Demod.highCnt++; } else { Demod.highCnt = 0; } } else { Demod.syncBit = 0xFFFF; // not set if ((Demod.twoBits & 0x7700) == 0x7000) Demod.syncBit = 7; else if ((Demod.twoBits & 0x3B80) == 0x3800) Demod.syncBit = 6; else if ((Demod.twoBits & 0x1DC0) == 0x1C00) Demod.syncBit = 5; else if ((Demod.twoBits & 0x0EE0) == 0x0E00) Demod.syncBit = 4; else if ((Demod.twoBits & 0x0770) == 0x0700) Demod.syncBit = 3; else if ((Demod.twoBits & 0x03B8) == 0x0380) Demod.syncBit = 2; else if ((Demod.twoBits & 0x01DC) == 0x01C0) Demod.syncBit = 1; else if ((Demod.twoBits & 0x00EE) == 0x00E0) Demod.syncBit = 0; if (Demod.syncBit != 0xFFFF) { Demod.startTime = non_real_time?non_real_time:(GetCountSspClk() & 0xfffffff8); Demod.startTime -= Demod.syncBit; Demod.bitCount = offset; // number of decoded data bits Demod.state = DEMOD_MANCHESTER_DATA; } } } else { if (IsManchesterModulationNibble1(Demod.twoBits >> Demod.syncBit)) { // modulation in first half if (IsManchesterModulationNibble2(Demod.twoBits >> Demod.syncBit)) { // ... and in second half = collision if (!Demod.collisionPos) { Demod.collisionPos = (Demod.len << 3) + Demod.bitCount; } } // modulation in first half only - Sequence D = 1 Demod.bitCount++; Demod.shiftReg = (Demod.shiftReg >> 1) | 0x100; // in both cases, add a 1 to the shiftreg if(Demod.bitCount == 9) { // if we decoded a full byte (including parity) Demod.output[Demod.len++] = (Demod.shiftReg & 0xff); Demod.parityBits <<= 1; // make room for the parity bit Demod.parityBits |= ((Demod.shiftReg >> 8) & 0x01); // store parity bit Demod.bitCount = 0; Demod.shiftReg = 0; if((Demod.len&0x0007) == 0) { // every 8 data bytes Demod.parity[Demod.parityLen++] = Demod.parityBits; // store 8 parity bits Demod.parityBits = 0; } } Demod.endTime = Demod.startTime + 8*(9*Demod.len + Demod.bitCount + 1) - 4; } else { // no modulation in first half if (IsManchesterModulationNibble2(Demod.twoBits >> Demod.syncBit)) { // and modulation in second half = Sequence E = 0 Demod.bitCount++; Demod.shiftReg = (Demod.shiftReg >> 1); // add a 0 to the shiftreg if(Demod.bitCount >= 9) { // if we decoded a full byte (including parity) Demod.output[Demod.len++] = (Demod.shiftReg & 0xff); Demod.parityBits <<= 1; // make room for the new parity bit Demod.parityBits |= ((Demod.shiftReg >> 8) & 0x01); // store parity bit Demod.bitCount = 0; Demod.shiftReg = 0; if ((Demod.len&0x0007) == 0) { // every 8 data bytes Demod.parity[Demod.parityLen++] = Demod.parityBits; // store 8 parity bits1 Demod.parityBits = 0; } } Demod.endTime = Demod.startTime + 8*(9*Demod.len + Demod.bitCount + 1); } else { // no modulation in both halves - End of communication if(Demod.bitCount > 0) { // there are some remaining data bits Demod.shiftReg >>= (9 - Demod.bitCount); // right align the decoded bits Demod.output[Demod.len++] = Demod.shiftReg & 0xff; // and add them to the output Demod.parityBits <<= 1; // add a (void) parity bit Demod.parityBits <<= (8 - (Demod.len&0x0007)); // left align remaining parity bits Demod.parity[Demod.parityLen++] = Demod.parityBits; // and store them return TRUE; } else if (Demod.len & 0x0007) { // there are some parity bits to store Demod.parityBits <<= (8 - (Demod.len&0x0007)); // left align remaining parity bits Demod.parity[Demod.parityLen++] = Demod.parityBits; // and store them } if (Demod.len) { return TRUE; // we are finished with decoding the raw data sequence } else { // nothing received. Start over DemodReset(); } } } } return FALSE; // not finished yet, need more data } //============================================================================= // Finally, a `sniffer' for ISO 14443 Type A // Both sides of communication! //============================================================================= //----------------------------------------------------------------------------- // Record the sequence of commands sent by the reader to the tag, with // triggering so that we start recording at the point that the tag is moved // near the reader. //----------------------------------------------------------------------------- void RAMFUNC SnoopIso14443a(uint8_t param) { // param: // bit 0 - trigger from first card answer // bit 1 - trigger from first reader 7-bit request 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 // response from the tag. // triggered == FALSE -- to wait first for card bool triggered = !(param & 0x03); // The command (reader -> tag) that we're receiving. // The length of a received command will in most cases be no more than 18 bytes. // So 32 should be enough! uint8_t *receivedCmd = BigBuf_get_addr() + RECV_CMD_OFFSET; uint8_t *receivedCmdPar = BigBuf_get_addr() + RECV_CMD_PAR_OFFSET; // The response (tag -> reader) that we're receiving. uint8_t *receivedResponse = BigBuf_get_addr() + RECV_RESP_OFFSET; uint8_t *receivedResponsePar = BigBuf_get_addr() + RECV_RESP_PAR_OFFSET; // As we receive stuff, we copy it from receivedCmd or receivedResponse // into trace, along with its length and other annotations. //uint8_t *trace = (uint8_t *)BigBuf; // The DMA buffer, used to stream samples from the FPGA uint8_t *dmaBuf = BigBuf_get_addr() + DMA_BUFFER_OFFSET; uint8_t *data = dmaBuf; uint8_t previous_data = 0; int maxDataLen = 0; int dataLen = 0; bool TagIsActive = FALSE; bool ReaderIsActive = FALSE; iso14443a_setup(FPGA_HF_ISO14443A_SNIFFER); // Set up the demodulator for tag -> reader responses. DemodInit(receivedResponse, receivedResponsePar); // Set up the demodulator for the reader -> tag commands UartInit(receivedCmd, receivedCmdPar); // Setup and start DMA. FpgaSetupSscDma((uint8_t *)dmaBuf, DMA_BUFFER_SIZE); // And now we loop, receiving samples. for(uint32_t rsamples = 0; TRUE; ) { if(BUTTON_PRESS()) { DbpString("cancelled by button"); break; } LED_A_ON(); WDT_HIT(); int register readBufDataP = data - dmaBuf; int register dmaBufDataP = DMA_BUFFER_SIZE - AT91C_BASE_PDC_SSC->PDC_RCR; if (readBufDataP <= dmaBufDataP){ dataLen = dmaBufDataP - readBufDataP; } else { dataLen = DMA_BUFFER_SIZE - readBufDataP + dmaBufDataP; } // test for length of buffer if(dataLen > maxDataLen) { maxDataLen = dataLen; if(dataLen > 400) { Dbprintf("blew circular buffer! dataLen=%d", dataLen); break; } } if(dataLen < 1) continue; // primary buffer was stopped( <-- we lost data! if (!AT91C_BASE_PDC_SSC->PDC_RCR) { AT91C_BASE_PDC_SSC->PDC_RPR = (uint32_t) dmaBuf; AT91C_BASE_PDC_SSC->PDC_RCR = DMA_BUFFER_SIZE; Dbprintf("RxEmpty ERROR!!! data length:%d", dataLen); // temporary } // secondary buffer sets as primary, secondary buffer was stopped if (!AT91C_BASE_PDC_SSC->PDC_RNCR) { AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) dmaBuf; AT91C_BASE_PDC_SSC->PDC_RNCR = DMA_BUFFER_SIZE; } LED_A_OFF(); if (rsamples & 0x01) { // Need two samples to feed Miller and Manchester-Decoder if(!TagIsActive) { // no need to try decoding reader data if the tag is sending uint8_t readerdata = (previous_data & 0xF0) | (*data >> 4); if (MillerDecoding(readerdata, (rsamples-1)*4)) { LED_C_ON(); // check - if there is a short 7bit request from reader if ((!triggered) && (param & 0x02) && (Uart.len == 1) && (Uart.bitCount == 7)) triggered = TRUE; if(triggered) { if (!LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_READER_AIR2ARM_AS_SNIFFER, Uart.endTime*16 - DELAY_READER_AIR2ARM_AS_SNIFFER, Uart.parity, TRUE)) break; } /* And ready to receive another command. */ UartReset(); /* And also reset the demod code, which might have been */ /* false-triggered by the commands from the reader. */ DemodReset(); LED_B_OFF(); } ReaderIsActive = (Uart.state != STATE_UNSYNCD); } if(!ReaderIsActive) { // no need to try decoding tag data if the reader is sending - and we cannot afford the time uint8_t tagdata = (previous_data << 4) | (*data & 0x0F); if(ManchesterDecoding(tagdata, 0, (rsamples-1)*4)) { LED_B_ON(); if (!LogTrace(receivedResponse, Demod.len, Demod.startTime*16 - DELAY_TAG_AIR2ARM_AS_SNIFFER, Demod.endTime*16 - DELAY_TAG_AIR2ARM_AS_SNIFFER, Demod.parity, FALSE)) break; if ((!triggered) && (param & 0x01)) triggered = TRUE; // And ready to receive another response. DemodReset(); LED_C_OFF(); } TagIsActive = (Demod.state != DEMOD_UNSYNCD); } } previous_data = *data; rsamples++; data++; if(data == dmaBuf + DMA_BUFFER_SIZE) { data = dmaBuf; } } // main cycle DbpString("COMMAND FINISHED"); FpgaDisableSscDma(); Dbprintf("maxDataLen=%d, Uart.state=%x, Uart.len=%d", maxDataLen, Uart.state, Uart.len); Dbprintf("traceLen=%d, Uart.output[0]=%08x", traceLen, (uint32_t)Uart.output[0]); LEDsoff(); } //----------------------------------------------------------------------------- // Prepare tag messages //----------------------------------------------------------------------------- static void CodeIso14443aAsTagPar(const uint8_t *cmd, uint16_t len, uint8_t *parity) { ToSendReset(); // Correction bit, might be removed when not needed ToSendStuffBit(0); ToSendStuffBit(0); ToSendStuffBit(0); ToSendStuffBit(0); ToSendStuffBit(1); // 1 ToSendStuffBit(0); ToSendStuffBit(0); ToSendStuffBit(0); // Send startbit ToSend[++ToSendMax] = SEC_D; LastProxToAirDuration = 8 * ToSendMax - 4; for(uint16_t i = 0; i < len; i++) { uint8_t b = cmd[i]; // Data bits for(uint16_t j = 0; j < 8; j++) { if(b & 1) { ToSend[++ToSendMax] = SEC_D; } else { ToSend[++ToSendMax] = SEC_E; } b >>= 1; } // Get the parity bit if (parity[i>>3] & (0x80>>(i&0x0007))) { ToSend[++ToSendMax] = SEC_D; LastProxToAirDuration = 8 * ToSendMax - 4; } else { ToSend[++ToSendMax] = SEC_E; LastProxToAirDuration = 8 * ToSendMax; } } // Send stopbit ToSend[++ToSendMax] = SEC_F; // Convert from last byte pos to length ToSendMax++; } static void CodeIso14443aAsTag(const uint8_t *cmd, uint16_t len) { uint8_t par[MAX_PARITY_SIZE]; GetParity(cmd, len, par); CodeIso14443aAsTagPar(cmd, len, par); } static void Code4bitAnswerAsTag(uint8_t cmd) { int i; ToSendReset(); // Correction bit, might be removed when not needed ToSendStuffBit(0); ToSendStuffBit(0); ToSendStuffBit(0); ToSendStuffBit(0); ToSendStuffBit(1); // 1 ToSendStuffBit(0); ToSendStuffBit(0); ToSendStuffBit(0); // Send startbit ToSend[++ToSendMax] = SEC_D; uint8_t b = cmd; for(i = 0; i < 4; i++) { if(b & 1) { ToSend[++ToSendMax] = SEC_D; LastProxToAirDuration = 8 * ToSendMax - 4; } else { ToSend[++ToSendMax] = SEC_E; LastProxToAirDuration = 8 * ToSendMax; } b >>= 1; } // Send stopbit ToSend[++ToSendMax] = SEC_F; // Convert from last byte pos to length ToSendMax++; } //----------------------------------------------------------------------------- // Wait for commands from reader // Stop when button is pressed // Or return TRUE when command is captured //----------------------------------------------------------------------------- static int GetIso14443aCommandFromReader(uint8_t *received, uint8_t *parity, int *len) { // Set FPGA mode to "simulated ISO 14443 tag", no modulation (listen // only, since we are receiving, not transmitting). // Signal field is off with the appropriate LED LED_D_OFF(); FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_LISTEN); // Now run a `software UART' on the stream of incoming samples. UartInit(received, parity); // clear RXRDY: uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR; for(;;) { WDT_HIT(); if(BUTTON_PRESS()) return FALSE; if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) { b = (uint8_t)AT91C_BASE_SSC->SSC_RHR; if(MillerDecoding(b, 0)) { *len = Uart.len; return TRUE; } } } } static int EmSendCmd14443aRaw(uint8_t *resp, uint16_t respLen, bool correctionNeeded); int EmSend4bitEx(uint8_t resp, bool correctionNeeded); int EmSend4bit(uint8_t resp); int EmSendCmdExPar(uint8_t *resp, uint16_t respLen, bool correctionNeeded, uint8_t *par); int EmSendCmdEx(uint8_t *resp, uint16_t respLen, bool correctionNeeded); int EmSendCmd(uint8_t *resp, uint16_t respLen); int EmSendCmdPar(uint8_t *resp, uint16_t respLen, uint8_t *par); bool EmLogTrace(uint8_t *reader_data, uint16_t reader_len, uint32_t reader_StartTime, uint32_t reader_EndTime, uint8_t *reader_Parity, uint8_t *tag_data, uint16_t tag_len, uint32_t tag_StartTime, uint32_t tag_EndTime, uint8_t *tag_Parity); static uint8_t* free_buffer_pointer; typedef struct { uint8_t* response; size_t response_n; uint8_t* modulation; size_t modulation_n; uint32_t ProxToAirDuration; } tag_response_info_t; void reset_free_buffer() { free_buffer_pointer = BigBuf_get_addr() + FREE_BUFFER_OFFSET; } bool prepare_tag_modulation(tag_response_info_t* response_info, size_t max_buffer_size) { // Example response, answer to MIFARE Classic read block will be 16 bytes + 2 CRC = 18 bytes // This will need the following byte array for a modulation sequence // 144 data bits (18 * 8) // 18 parity bits // 2 Start and stop // 1 Correction bit (Answer in 1172 or 1236 periods, see FPGA) // 1 just for the case // ----------- + // 166 bytes, since every bit that needs to be send costs us a byte // // Prepare the tag modulation bits from the message CodeIso14443aAsTag(response_info->response,response_info->response_n); // Make sure we do not exceed the free buffer space if (ToSendMax > max_buffer_size) { Dbprintf("Out of memory, when modulating bits for tag answer:"); Dbhexdump(response_info->response_n,response_info->response,false); return false; } // Copy the byte array, used for this modulation to the buffer position memcpy(response_info->modulation,ToSend,ToSendMax); // Store the number of bytes that were used for encoding/modulation and the time needed to transfer them response_info->modulation_n = ToSendMax; response_info->ProxToAirDuration = LastProxToAirDuration; return true; } bool prepare_allocated_tag_modulation(tag_response_info_t* response_info) { // Retrieve and store the current buffer index response_info->modulation = free_buffer_pointer; // Determine the maximum size we can use from our buffer size_t max_buffer_size = BigBuf_get_addr() + FREE_BUFFER_OFFSET + FREE_BUFFER_SIZE - free_buffer_pointer; // Forward the prepare tag modulation function to the inner function if (prepare_tag_modulation(response_info,max_buffer_size)) { // Update the free buffer offset free_buffer_pointer += ToSendMax; return true; } else { return false; } } //----------------------------------------------------------------------------- // Main loop of simulated tag: receive commands from reader, decide what // response to send, and send it. //----------------------------------------------------------------------------- void SimulateIso14443aTag(int tagType, int uid_1st, int uid_2nd, byte_t* data) { // Enable and clear the trace iso14a_clear_trace(); iso14a_set_tracing(TRUE); uint8_t sak; // The first response contains the ATQA (note: bytes are transmitted in reverse order). uint8_t response1[2]; switch (tagType) { case 1: { // MIFARE Classic // Says: I am Mifare 1k - original line response1[0] = 0x04; response1[1] = 0x00; sak = 0x08; } break; case 2: { // MIFARE Ultralight // Says: I am a stupid memory tag, no crypto response1[0] = 0x04; response1[1] = 0x00; sak = 0x00; } break; case 3: { // MIFARE DESFire // Says: I am a DESFire tag, ph33r me response1[0] = 0x04; response1[1] = 0x03; sak = 0x20; } break; case 4: { // ISO/IEC 14443-4 // Says: I am a javacard (JCOP) response1[0] = 0x04; response1[1] = 0x00; sak = 0x28; } break; case 5: { // MIFARE TNP3XXX // Says: I am a toy response1[0] = 0x01; response1[1] = 0x0f; sak = 0x01; } break; default: { Dbprintf("Error: unkown tagtype (%d)",tagType); return; } break; } // The second response contains the (mandatory) first 24 bits of the UID uint8_t response2[5] = {0x00}; // Check if the uid uses the (optional) part uint8_t response2a[5] = {0x00}; if (uid_2nd) { response2[0] = 0x88; num_to_bytes(uid_1st,3,response2+1); num_to_bytes(uid_2nd,4,response2a); response2a[4] = response2a[0] ^ response2a[1] ^ response2a[2] ^ response2a[3]; // Configure the ATQA and SAK accordingly response1[0] |= 0x40; sak |= 0x04; } else { num_to_bytes(uid_1st,4,response2); // Configure the ATQA and SAK accordingly response1[0] &= 0xBF; sak &= 0xFB; } // Calculate the BitCountCheck (BCC) for the first 4 bytes of the UID. response2[4] = response2[0] ^ response2[1] ^ response2[2] ^ response2[3]; // Prepare the mandatory SAK (for 4 and 7 byte UID) uint8_t response3[3] = {0x00}; response3[0] = sak; ComputeCrc14443(CRC_14443_A, response3, 1, &response3[1], &response3[2]); // Prepare the optional second SAK (for 7 byte UID), drop the cascade bit uint8_t response3a[3] = {0x00}; response3a[0] = sak & 0xFB; ComputeCrc14443(CRC_14443_A, response3a, 1, &response3a[1], &response3a[2]); uint8_t response5[] = { 0x00, 0x00, 0x00, 0x00 }; // Very random tag nonce uint8_t response6[] = { 0x04, 0x58, 0x80, 0x02, 0x00, 0x00 }; // dummy ATS (pseudo-ATR), answer to RATS: // Format byte = 0x58: FSCI=0x08 (FSC=256), TA(1) and TC(1) present, // TA(1) = 0x80: different divisors not supported, DR = 1, DS = 1 // TB(1) = not present. Defaults: FWI = 4 (FWT = 256 * 16 * 2^4 * 1/fc = 4833us), SFGI = 0 (SFG = 256 * 16 * 2^0 * 1/fc = 302us) // TC(1) = 0x02: CID supported, NAD not supported ComputeCrc14443(CRC_14443_A, response6, 4, &response6[4], &response6[5]); #define TAG_RESPONSE_COUNT 7 tag_response_info_t responses[TAG_RESPONSE_COUNT] = { { .response = response1, .response_n = sizeof(response1) }, // Answer to request - respond with card type { .response = response2, .response_n = sizeof(response2) }, // Anticollision cascade1 - respond with uid { .response = response2a, .response_n = sizeof(response2a) }, // Anticollision cascade2 - respond with 2nd half of uid if asked { .response = response3, .response_n = sizeof(response3) }, // Acknowledge select - cascade 1 { .response = response3a, .response_n = sizeof(response3a) }, // Acknowledge select - cascade 2 { .response = response5, .response_n = sizeof(response5) }, // Authentication answer (random nonce) { .response = response6, .response_n = sizeof(response6) }, // dummy ATS (pseudo-ATR), answer to RATS }; // Allocate 512 bytes for the dynamic modulation, created when the reader queries for it // Such a response is less time critical, so we can prepare them on the fly #define DYNAMIC_RESPONSE_BUFFER_SIZE 64 #define DYNAMIC_MODULATION_BUFFER_SIZE 512 uint8_t dynamic_response_buffer[DYNAMIC_RESPONSE_BUFFER_SIZE]; uint8_t dynamic_modulation_buffer[DYNAMIC_MODULATION_BUFFER_SIZE]; tag_response_info_t dynamic_response_info = { .response = dynamic_response_buffer, .response_n = 0, .modulation = dynamic_modulation_buffer, .modulation_n = 0 }; // Reset the offset pointer of the free buffer reset_free_buffer(); // Prepare the responses of the anticollision phase // there will be not enough time to do this at the moment the reader sends it REQA for (size_t i=0; i 0) { // Copy the CID from the reader query dynamic_response_info.response[1] = receivedCmd[1]; // Add CRC bytes, always used in ISO 14443A-4 compliant cards AppendCrc14443a(dynamic_response_info.response,dynamic_response_info.response_n); dynamic_response_info.response_n += 2; if (prepare_tag_modulation(&dynamic_response_info,DYNAMIC_MODULATION_BUFFER_SIZE) == false) { Dbprintf("Error preparing tag response"); if (tracing) { LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE); } break; } p_response = &dynamic_response_info; } } // Count number of wakeups received after a halt if(order == 6 && lastorder == 5) { happened++; } // Count number of other messages after a halt if(order != 6 && lastorder == 5) { happened2++; } if(cmdsRecvd > 999) { DbpString("1000 commands later..."); break; } cmdsRecvd++; if (p_response != NULL) { EmSendCmd14443aRaw(p_response->modulation, p_response->modulation_n, receivedCmd[0] == 0x52); // do the tracing for the previous reader request and this tag answer: uint8_t par[MAX_PARITY_SIZE]; GetParity(p_response->response, p_response->response_n, par); EmLogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, p_response->response, p_response->response_n, LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_TAG, (LastTimeProxToAirStart + p_response->ProxToAirDuration)*16 + DELAY_ARM2AIR_AS_TAG, par); } if (!tracing) { Dbprintf("Trace Full. Simulation stopped."); break; } } Dbprintf("%x %x %x", happened, happened2, cmdsRecvd); LED_A_OFF(); } // prepare a delayed transfer. This simply shifts ToSend[] by a number // of bits specified in the delay parameter. void PrepareDelayedTransfer(uint16_t delay) { uint8_t bitmask = 0; uint8_t bits_to_shift = 0; uint8_t bits_shifted = 0; delay &= 0x07; if (delay) { for (uint16_t i = 0; i < delay; i++) { bitmask |= (0x01 << i); } ToSend[ToSendMax++] = 0x00; for (uint16_t i = 0; i < ToSendMax; i++) { bits_to_shift = ToSend[i] & bitmask; ToSend[i] = ToSend[i] >> delay; ToSend[i] = ToSend[i] | (bits_shifted << (8 - delay)); bits_shifted = bits_to_shift; } } } //------------------------------------------------------------------------------------- // Transmit the command (to the tag) that was placed in ToSend[]. // Parameter timing: // if NULL: transfer at next possible time, taking into account // request guard time and frame delay time // if == 0: transfer immediately and return time of transfer // if != 0: delay transfer until time specified //------------------------------------------------------------------------------------- static void TransmitFor14443a(const uint8_t *cmd, uint16_t len, uint32_t *timing) { FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_MOD); uint32_t ThisTransferTime = 0; if (timing) { if(*timing == 0) { // Measure time *timing = (GetCountSspClk() + 8) & 0xfffffff8; } else { PrepareDelayedTransfer(*timing & 0x00000007); // Delay transfer (fine tuning - up to 7 MF clock ticks) } if(MF_DBGLEVEL >= 4 && GetCountSspClk() >= (*timing & 0xfffffff8)) Dbprintf("TransmitFor14443a: Missed timing"); while(GetCountSspClk() < (*timing & 0xfffffff8)); // Delay transfer (multiple of 8 MF clock ticks) LastTimeProxToAirStart = *timing; } else { ThisTransferTime = ((MAX(NextTransferTime, GetCountSspClk()) & 0xfffffff8) + 8); while(GetCountSspClk() < ThisTransferTime); LastTimeProxToAirStart = ThisTransferTime; } // clear TXRDY AT91C_BASE_SSC->SSC_THR = SEC_Y; uint16_t c = 0; for(;;) { if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) { AT91C_BASE_SSC->SSC_THR = cmd[c]; c++; if(c >= len) { break; } } } NextTransferTime = MAX(NextTransferTime, LastTimeProxToAirStart + REQUEST_GUARD_TIME); } //----------------------------------------------------------------------------- // Prepare reader command (in bits, support short frames) to send to FPGA //----------------------------------------------------------------------------- void CodeIso14443aBitsAsReaderPar(const uint8_t *cmd, uint16_t bits, const uint8_t *parity) { int i, j; int last; uint8_t b; ToSendReset(); // Start of Communication (Seq. Z) ToSend[++ToSendMax] = SEC_Z; LastProxToAirDuration = 8 * (ToSendMax+1) - 6; last = 0; size_t bytecount = nbytes(bits); // Generate send structure for the data bits for (i = 0; i < bytecount; i++) { // Get the current byte to send b = cmd[i]; size_t bitsleft = MIN((bits-(i*8)),8); for (j = 0; j < bitsleft; j++) { if (b & 1) { // Sequence X ToSend[++ToSendMax] = SEC_X; LastProxToAirDuration = 8 * (ToSendMax+1) - 2; last = 1; } else { if (last == 0) { // Sequence Z ToSend[++ToSendMax] = SEC_Z; LastProxToAirDuration = 8 * (ToSendMax+1) - 6; } else { // Sequence Y ToSend[++ToSendMax] = SEC_Y; last = 0; } } b >>= 1; } // Only transmit parity bit if we transmitted a complete byte if (j == 8) { // Get the parity bit if (parity[i>>3] & (0x80 >> (i&0x0007))) { // Sequence X ToSend[++ToSendMax] = SEC_X; LastProxToAirDuration = 8 * (ToSendMax+1) - 2; last = 1; } else { if (last == 0) { // Sequence Z ToSend[++ToSendMax] = SEC_Z; LastProxToAirDuration = 8 * (ToSendMax+1) - 6; } else { // Sequence Y ToSend[++ToSendMax] = SEC_Y; last = 0; } } } } // End of Communication: Logic 0 followed by Sequence Y if (last == 0) { // Sequence Z ToSend[++ToSendMax] = SEC_Z; LastProxToAirDuration = 8 * (ToSendMax+1) - 6; } else { // Sequence Y ToSend[++ToSendMax] = SEC_Y; last = 0; } ToSend[++ToSendMax] = SEC_Y; // Convert to length of command: ToSendMax++; } //----------------------------------------------------------------------------- // Prepare reader command to send to FPGA //----------------------------------------------------------------------------- void CodeIso14443aAsReaderPar(const uint8_t *cmd, uint16_t len, const uint8_t *parity) { CodeIso14443aBitsAsReaderPar(cmd, len*8, parity); } //----------------------------------------------------------------------------- // Wait for commands from reader // Stop when button is pressed (return 1) or field was gone (return 2) // Or return 0 when command is captured //----------------------------------------------------------------------------- static int EmGetCmd(uint8_t *received, uint16_t *len, uint8_t *parity) { *len = 0; uint32_t timer = 0, vtime = 0; int analogCnt = 0; int analogAVG = 0; // Set FPGA mode to "simulated ISO 14443 tag", no modulation (listen // only, since we are receiving, not transmitting). // Signal field is off with the appropriate LED LED_D_OFF(); FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_LISTEN); // Set ADC to read field strength AT91C_BASE_ADC->ADC_CR = AT91C_ADC_SWRST; AT91C_BASE_ADC->ADC_MR = ADC_MODE_PRESCALE(32) | ADC_MODE_STARTUP_TIME(16) | ADC_MODE_SAMPLE_HOLD_TIME(8); AT91C_BASE_ADC->ADC_CHER = ADC_CHANNEL(ADC_CHAN_HF); // start ADC AT91C_BASE_ADC->ADC_CR = AT91C_ADC_START; // Now run a 'software UART' on the stream of incoming samples. UartInit(received, parity); // Clear RXRDY: uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR; for(;;) { WDT_HIT(); if (BUTTON_PRESS()) return 1; // test if the field exists if (AT91C_BASE_ADC->ADC_SR & ADC_END_OF_CONVERSION(ADC_CHAN_HF)) { analogCnt++; analogAVG += AT91C_BASE_ADC->ADC_CDR[ADC_CHAN_HF]; AT91C_BASE_ADC->ADC_CR = AT91C_ADC_START; if (analogCnt >= 32) { if ((33000 * (analogAVG / analogCnt) >> 10) < MF_MINFIELDV) { vtime = GetTickCount(); if (!timer) timer = vtime; // 50ms no field --> card to idle state if (vtime - timer > 50) return 2; } else if (timer) timer = 0; analogCnt = 0; analogAVG = 0; } } // receive and test the miller decoding if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) { b = (uint8_t)AT91C_BASE_SSC->SSC_RHR; if(MillerDecoding(b, 0)) { *len = Uart.len; return 0; } } } } static int EmSendCmd14443aRaw(uint8_t *resp, uint16_t respLen, bool correctionNeeded) { uint8_t b; uint16_t i = 0; uint32_t ThisTransferTime; // Modulate Manchester FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_MOD); // include correction bit if necessary if (Uart.parityBits & 0x01) { correctionNeeded = TRUE; } if(correctionNeeded) { // 1236, so correction bit needed i = 0; } else { i = 1; } // 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)); b = AT91C_BASE_SSC->SSC_RHR; (void) b; // wait for the FPGA to signal fdt_indicator == 1 (the FPGA is ready to queue new data in its delay line) for (uint16_t j = 0; j < 5; j++) { // allow timeout - better late than never while(!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY)); if (AT91C_BASE_SSC->SSC_RHR) break; } while ((ThisTransferTime = GetCountSspClk()) & 0x00000007); // Clear TXRDY: AT91C_BASE_SSC->SSC_THR = SEC_F; // send cycle for(; i <= respLen; ) { if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) { AT91C_BASE_SSC->SSC_THR = resp[i++]; FpgaSendQueueDelay = (uint8_t)AT91C_BASE_SSC->SSC_RHR; } if(BUTTON_PRESS()) { break; } } // Ensure that the FPGA Delay Queue is empty before we switch to TAGSIM_LISTEN again: for (i = 0; i < 2 ; ) { if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) { AT91C_BASE_SSC->SSC_THR = SEC_F; FpgaSendQueueDelay = (uint8_t)AT91C_BASE_SSC->SSC_RHR; i++; } } LastTimeProxToAirStart = ThisTransferTime + (correctionNeeded?8:0); return 0; } int EmSend4bitEx(uint8_t resp, bool correctionNeeded){ Code4bitAnswerAsTag(resp); int res = EmSendCmd14443aRaw(ToSend, ToSendMax, correctionNeeded); // do the tracing for the previous reader request and this tag answer: uint8_t par[1]; GetParity(&resp, 1, par); EmLogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, &resp, 1, LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_TAG, (LastTimeProxToAirStart + LastProxToAirDuration)*16 + DELAY_ARM2AIR_AS_TAG, par); return res; } int EmSend4bit(uint8_t resp){ return EmSend4bitEx(resp, false); } int EmSendCmdExPar(uint8_t *resp, uint16_t respLen, bool correctionNeeded, uint8_t *par){ CodeIso14443aAsTagPar(resp, respLen, par); int res = EmSendCmd14443aRaw(ToSend, ToSendMax, correctionNeeded); // do the tracing for the previous reader request and this tag answer: EmLogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, resp, respLen, LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_TAG, (LastTimeProxToAirStart + LastProxToAirDuration)*16 + DELAY_ARM2AIR_AS_TAG, par); return res; } int EmSendCmdEx(uint8_t *resp, uint16_t respLen, bool correctionNeeded){ uint8_t par[MAX_PARITY_SIZE]; GetParity(resp, respLen, par); return EmSendCmdExPar(resp, respLen, correctionNeeded, par); } int EmSendCmd(uint8_t *resp, uint16_t respLen){ uint8_t par[MAX_PARITY_SIZE]; GetParity(resp, respLen, par); return EmSendCmdExPar(resp, respLen, false, par); } int EmSendCmdPar(uint8_t *resp, uint16_t respLen, uint8_t *par){ return EmSendCmdExPar(resp, respLen, false, par); } bool EmLogTrace(uint8_t *reader_data, uint16_t reader_len, uint32_t reader_StartTime, uint32_t reader_EndTime, uint8_t *reader_Parity, uint8_t *tag_data, uint16_t tag_len, uint32_t tag_StartTime, uint32_t tag_EndTime, uint8_t *tag_Parity) { if (tracing) { // we cannot exactly measure the end and start of a received command from reader. However we know that the delay from // end of the received command to start of the tag's (simulated by us) answer is n*128+20 or n*128+84 resp. // with n >= 9. The start of the tags answer can be measured and therefore the end of the received command be calculated: uint16_t reader_modlen = reader_EndTime - reader_StartTime; uint16_t approx_fdt = tag_StartTime - reader_EndTime; uint16_t exact_fdt = (approx_fdt - 20 + 32)/64 * 64 + 20; reader_EndTime = tag_StartTime - exact_fdt; reader_StartTime = reader_EndTime - reader_modlen; if (!LogTrace(reader_data, reader_len, reader_StartTime, reader_EndTime, reader_Parity, TRUE)) { return FALSE; } else return(!LogTrace(tag_data, tag_len, tag_StartTime, tag_EndTime, tag_Parity, FALSE)); } else { return TRUE; } } //----------------------------------------------------------------------------- // Wait a certain time for tag response // If a response is captured return TRUE // If it takes too long return FALSE //----------------------------------------------------------------------------- static int GetIso14443aAnswerFromTag(uint8_t *receivedResponse, uint8_t *receivedResponsePar, uint16_t offset) { uint32_t c; // Set FPGA mode to "reader listen mode", no modulation (listen // only, since we are receiving, not transmitting). // Signal field is on with the appropriate LED LED_D_ON(); FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_LISTEN); // Now get the answer from the card DemodInit(receivedResponse, receivedResponsePar); // clear RXRDY: uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR; c = 0; for(;;) { WDT_HIT(); if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) { b = (uint8_t)AT91C_BASE_SSC->SSC_RHR; if(ManchesterDecoding(b, offset, 0)) { NextTransferTime = MAX(NextTransferTime, Demod.endTime - (DELAY_AIR2ARM_AS_READER + DELAY_ARM2AIR_AS_READER)/16 + FRAME_DELAY_TIME_PICC_TO_PCD); return TRUE; } else if (c++ > iso14a_timeout) { return FALSE; } } } } void ReaderTransmitBitsPar(uint8_t* frame, uint16_t bits, uint8_t *par, uint32_t *timing) { CodeIso14443aBitsAsReaderPar(frame, bits, par); // Send command to tag TransmitFor14443a(ToSend, ToSendMax, timing); if(trigger) LED_A_ON(); // Log reader command in trace buffer if (tracing) { LogTrace(frame, nbytes(bits), LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_READER, (LastTimeProxToAirStart + LastProxToAirDuration)*16 + DELAY_ARM2AIR_AS_READER, par, TRUE); } } 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 uint8_t par[MAX_PARITY_SIZE]; GetParity(frame, len/8, par); ReaderTransmitBitsPar(frame, len, par, timing); } void ReaderTransmit(uint8_t* frame, uint16_t len, uint32_t *timing) { // Generate parity and redirect uint8_t par[MAX_PARITY_SIZE]; GetParity(frame, len, par); ReaderTransmitBitsPar(frame, len*8, par, timing); } int ReaderReceiveOffset(uint8_t* receivedAnswer, uint16_t offset, uint8_t *parity) { if (!GetIso14443aAnswerFromTag(receivedAnswer, parity, offset)) return FALSE; if (tracing) { LogTrace(receivedAnswer, Demod.len, Demod.startTime*16 - DELAY_AIR2ARM_AS_READER, Demod.endTime*16 - DELAY_AIR2ARM_AS_READER, parity, FALSE); } return Demod.len; } int ReaderReceive(uint8_t *receivedAnswer, uint8_t *parity) { if (!GetIso14443aAnswerFromTag(receivedAnswer, parity, 0)) return FALSE; if (tracing) { LogTrace(receivedAnswer, Demod.len, Demod.startTime*16 - DELAY_AIR2ARM_AS_READER, Demod.endTime*16 - DELAY_AIR2ARM_AS_READER, parity, FALSE); } return Demod.len; } /* performs iso14443a anticollision procedure * fills the uid pointer unless NULL * fills resp_data unless NULL */ int iso14443a_select_card(byte_t *uid_ptr, iso14a_card_select_t *p_hi14a_card, uint32_t *cuid_ptr) { uint8_t wupa[] = { 0x52 }; // 0x26 - REQA 0x52 - WAKE-UP uint8_t sel_all[] = { 0x93,0x20 }; uint8_t sel_uid[] = { 0x93,0x70,0x00,0x00,0x00,0x00,0x00,0x00,0x00}; uint8_t rats[] = { 0xE0,0x80,0x00,0x00 }; // FSD=256, FSDI=8, CID=0 uint8_t *resp = BigBuf_get_addr() + RECV_RESP_OFFSET; uint8_t *resp_par = BigBuf_get_addr() + RECV_RESP_PAR_OFFSET; byte_t uid_resp[4]; size_t uid_resp_len; uint8_t sak = 0x04; // cascade uid int cascade_level = 0; int len; // Broadcast for a card, WUPA (0x52) will force response from all cards in the field ReaderTransmitBitsPar(wupa,7,0, NULL); // Receive the ATQA if(!ReaderReceive(resp, resp_par)) return 0; if(p_hi14a_card) { memcpy(p_hi14a_card->atqa, resp, 2); p_hi14a_card->uidlen = 0; memset(p_hi14a_card->uid,0,10); } // clear uid if (uid_ptr) { memset(uid_ptr,0,10); } // 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. for(; sak & 0x04; cascade_level++) { // SELECT_* (L1: 0x93, L2: 0x95, L3: 0x97) sel_uid[0] = sel_all[0] = 0x93 + cascade_level * 2; // SELECT_ALL ReaderTransmit(sel_all, sizeof(sel_all), NULL); if (!ReaderReceive(resp, resp_par)) return 0; if (Demod.collisionPos) { // we had a collision and need to construct the UID bit by bit memset(uid_resp, 0, 4); uint16_t uid_resp_bits = 0; uint16_t collision_answer_offset = 0; // anti-collision-loop: while (Demod.collisionPos) { Dbprintf("Multiple tags detected. Collision after Bit %d", Demod.collisionPos); for (uint16_t i = collision_answer_offset; i < Demod.collisionPos; i++, uid_resp_bits++) { // add valid UID bits before collision point uint16_t UIDbit = (resp[i/8] >> (i % 8)) & 0x01; uid_resp[uid_resp_bits / 8] |= UIDbit << (uid_resp_bits % 8); } uid_resp[uid_resp_bits/8] |= 1 << (uid_resp_bits % 8); // next time select the card(s) with a 1 in the collision position uid_resp_bits++; // construct anticollosion command: sel_uid[1] = ((2 + uid_resp_bits/8) << 4) | (uid_resp_bits & 0x07); // length of data in bytes and bits for (uint16_t i = 0; i <= uid_resp_bits/8; i++) { sel_uid[2+i] = uid_resp[i]; } collision_answer_offset = uid_resp_bits%8; ReaderTransmitBits(sel_uid, 16 + uid_resp_bits, NULL); if (!ReaderReceiveOffset(resp, collision_answer_offset, resp_par)) return 0; } // finally, add the last bits and BCC of the UID for (uint16_t i = collision_answer_offset; i < (Demod.len-1)*8; i++, uid_resp_bits++) { uint16_t UIDbit = (resp[i/8] >> (i%8)) & 0x01; uid_resp[uid_resp_bits/8] |= UIDbit << (uid_resp_bits % 8); } } else { // no collision, use the response to SELECT_ALL as current uid memcpy(uid_resp, resp, 4); } uid_resp_len = 4; // calculate crypto UID. Always use last 4 Bytes. if(cuid_ptr) { *cuid_ptr = bytes_to_num(uid_resp, 4); } // Construct SELECT UID command sel_uid[1] = 0x70; // transmitting a full UID (1 Byte cmd, 1 Byte NVB, 4 Byte UID, 1 Byte BCC, 2 Bytes CRC) memcpy(sel_uid+2, uid_resp, 4); // the UID sel_uid[6] = sel_uid[2] ^ sel_uid[3] ^ sel_uid[4] ^ sel_uid[5]; // calculate and add BCC AppendCrc14443a(sel_uid, 7); // calculate and add CRC ReaderTransmit(sel_uid, sizeof(sel_uid), NULL); // Receive the SAK if (!ReaderReceive(resp, resp_par)) return 0; sak = resp[0]; // Test if more parts of the uid are coming if ((sak & 0x04) /* && uid_resp[0] == 0x88 */) { // Remove first byte, 0x88 is not an UID byte, it CT, see page 3 of: // http://www.nxp.com/documents/application_note/AN10927.pdf uid_resp[0] = uid_resp[1]; uid_resp[1] = uid_resp[2]; uid_resp[2] = uid_resp[3]; uid_resp_len = 3; } if(uid_ptr) { memcpy(uid_ptr + (cascade_level*3), uid_resp, uid_resp_len); } if(p_hi14a_card) { memcpy(p_hi14a_card->uid + (cascade_level*3), uid_resp, uid_resp_len); p_hi14a_card->uidlen += uid_resp_len; } } if(p_hi14a_card) { p_hi14a_card->sak = sak; p_hi14a_card->ats_len = 0; } // non iso14443a compliant tag if( (sak & 0x20) == 0) return 2; // Request for answer to select AppendCrc14443a(rats, 2); ReaderTransmit(rats, sizeof(rats), NULL); if (!(len = ReaderReceive(resp, resp_par))) return 0; if(p_hi14a_card) { memcpy(p_hi14a_card->ats, resp, sizeof(p_hi14a_card->ats)); p_hi14a_card->ats_len = len; } // reset the PCB block number iso14_pcb_blocknum = 0; return 1; } void iso14443a_setup(uint8_t fpga_minor_mode) { FpgaDownloadAndGo(FPGA_BITSTREAM_HF); // Set up the synchronous serial port FpgaSetupSsc(); // connect Demodulated Signal to ADC: SetAdcMuxFor(GPIO_MUXSEL_HIPKD); // Signal field is on with the appropriate LED if (fpga_minor_mode == FPGA_HF_ISO14443A_READER_MOD || fpga_minor_mode == FPGA_HF_ISO14443A_READER_LISTEN) { LED_D_ON(); } else { LED_D_OFF(); } FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | fpga_minor_mode); // Start the timer StartCountSspClk(); DemodReset(); UartReset(); NextTransferTime = 2*DELAY_ARM2AIR_AS_READER; iso14a_set_timeout(1050); // 10ms default } int iso14_apdu(uint8_t *cmd, uint16_t cmd_len, void *data) { uint8_t parity[MAX_PARITY_SIZE]; uint8_t real_cmd[cmd_len+4]; real_cmd[0] = 0x0a; //I-Block // put block number into the PCB real_cmd[0] |= iso14_pcb_blocknum; real_cmd[1] = 0x00; //CID: 0 //FIXME: allow multiple selected cards memcpy(real_cmd+2, cmd, cmd_len); AppendCrc14443a(real_cmd,cmd_len+2); ReaderTransmit(real_cmd, cmd_len+4, NULL); size_t len = ReaderReceive(data, parity); uint8_t *data_bytes = (uint8_t *) data; if (!len) return 0; //DATA LINK ERROR // if we received an I- or R(ACK)-Block with a block number equal to the // current block number, toggle the current block number else if (len >= 4 // PCB+CID+CRC = 4 bytes && ((data_bytes[0] & 0xC0) == 0 // I-Block || (data_bytes[0] & 0xD0) == 0x80) // R-Block with ACK bit set to 0 && (data_bytes[0] & 0x01) == iso14_pcb_blocknum) // equal block numbers { iso14_pcb_blocknum ^= 1; } return len; } //----------------------------------------------------------------------------- // Read an ISO 14443a tag. Send out commands and store answers. // //----------------------------------------------------------------------------- void ReaderIso14443a(UsbCommand *c) { iso14a_command_t param = c->arg[0]; uint8_t *cmd = c->d.asBytes; size_t len = c->arg[1]; size_t lenbits = c->arg[2]; uint32_t arg0 = 0; byte_t buf[USB_CMD_DATA_SIZE]; uint8_t par[MAX_PARITY_SIZE]; if(param & ISO14A_CONNECT) { iso14a_clear_trace(); } iso14a_set_tracing(TRUE); if(param & ISO14A_REQUEST_TRIGGER) { iso14a_set_trigger(TRUE); } if(param & ISO14A_CONNECT) { iso14443a_setup(FPGA_HF_ISO14443A_READER_LISTEN); if(!(param & ISO14A_NO_SELECT)) { iso14a_card_select_t *card = (iso14a_card_select_t*)buf; arg0 = iso14443a_select_card(NULL,card,NULL); cmd_send(CMD_ACK,arg0,card->uidlen,0,buf,sizeof(iso14a_card_select_t)); } } if(param & ISO14A_SET_TIMEOUT) { iso14a_set_timeout(c->arg[2]); } if(param & ISO14A_APDU) { arg0 = iso14_apdu(cmd, len, buf); cmd_send(CMD_ACK,arg0,0,0,buf,sizeof(buf)); } if(param & ISO14A_RAW) { if(param & ISO14A_APPEND_CRC) { 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); } arg0 = ReaderReceive(buf, par); cmd_send(CMD_ACK,arg0,0,0,buf,sizeof(buf)); } if(param & ISO14A_REQUEST_TRIGGER) { iso14a_set_trigger(FALSE); } if(param & ISO14A_NO_DISCONNECT) { return; } FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); LEDsoff(); } // Determine the distance between two nonces. // Assume that the difference is small, but we don't know which is first. // Therefore try in alternating directions. int32_t dist_nt(uint32_t nt1, uint32_t nt2) { uint16_t i; uint32_t nttmp1, nttmp2; if (nt1 == nt2) return 0; nttmp1 = nt1; nttmp2 = nt2; for (i = 1; i < 32768; i++) { nttmp1 = prng_successor(nttmp1, 1); if (nttmp1 == nt2) return i; nttmp2 = prng_successor(nttmp2, 1); if (nttmp2 == nt1) return -i; } return(-99999); // either nt1 or nt2 are invalid nonces } //----------------------------------------------------------------------------- // Recover several bits of the cypher stream. This implements (first stages of) // the algorithm described in "The Dark Side of Security by Obscurity and // Cloning MiFare Classic Rail and Building Passes, Anywhere, Anytime" // (article by Nicolas T. Courtois, 2009) //----------------------------------------------------------------------------- void ReaderMifare(bool first_try) { // Mifare AUTH uint8_t mf_auth[] = { 0x60,0x00,0xf5,0x7b }; uint8_t mf_nr_ar[] = { 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00 }; static uint8_t mf_nr_ar3; uint8_t* receivedAnswer = BigBuf_get_addr() + RECV_RESP_OFFSET; uint8_t* receivedAnswerPar = BigBuf_get_addr() + RECV_RESP_PAR_OFFSET; iso14a_clear_trace(); iso14a_set_tracing(TRUE); byte_t nt_diff = 0; uint8_t par[1] = {0}; // maximum 8 Bytes to be sent here, 1 byte parity is therefore enough static byte_t par_low = 0; bool led_on = TRUE; uint8_t uid[10] ={0}; uint32_t cuid; uint32_t nt = 0; uint32_t previous_nt = 0; static uint32_t nt_attacked = 0; byte_t par_list[8] = {0x00}; byte_t ks_list[8] = {0x00}; static uint32_t sync_time; static uint32_t sync_cycles; int catch_up_cycles = 0; int last_catch_up = 0; uint16_t consecutive_resyncs = 0; int isOK = 0; if (first_try) { mf_nr_ar3 = 0; iso14443a_setup(FPGA_HF_ISO14443A_READER_MOD); sync_time = GetCountSspClk() & 0xfffffff8; sync_cycles = 65536; // theory: Mifare Classic's random generator repeats every 2^16 cycles (and so do the nonces). nt_attacked = 0; nt = 0; par[0] = 0; } else { // we were unsuccessful on a previous call. Try another READER nonce (first 3 parity bits remain the same) mf_nr_ar3++; mf_nr_ar[3] = mf_nr_ar3; par[0] = par_low; } LED_A_ON(); LED_B_OFF(); LED_C_OFF(); for(uint16_t i = 0; TRUE; i++) { WDT_HIT(); // Test if the action was cancelled if(BUTTON_PRESS()) { break; } LED_C_ON(); if(!iso14443a_select_card(uid, NULL, &cuid)) { if (MF_DBGLEVEL >= 1) Dbprintf("Mifare: Can't select card"); continue; } 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; } // Transmit MIFARE_CLASSIC_AUTH at synctime. Should result in returning the same tag nonce (== nt_attacked) ReaderTransmit(mf_auth, sizeof(mf_auth), &sync_time); // Receive the (4 Byte) "random" nonce if (!ReaderReceive(receivedAnswer, receivedAnswerPar)) { if (MF_DBGLEVEL >= 1) Dbprintf("Mifare: Couldn't receive tag nonce"); continue; } previous_nt = nt; nt = bytes_to_num(receivedAnswer, 4); // Transmit reader nonce with fake par ReaderTransmitPar(mf_nr_ar, sizeof(mf_nr_ar), par, NULL); if (first_try && previous_nt && !nt_attacked) { // we didn't calibrate our clock yet int nt_distance = dist_nt(previous_nt, nt); if (nt_distance == 0) { nt_attacked = nt; } else { if (nt_distance == -99999) { // invalid nonce received, try again continue; } 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); continue; } } if ((nt != nt_attacked) && nt_attacked) { // we somehow lost sync. Try to catch up again... catch_up_cycles = -dist_nt(nt_attacked, nt); if (catch_up_cycles == 99999) { // invalid nonce received. Don't resync on that one. catch_up_cycles = 0; continue; } if (catch_up_cycles == last_catch_up) { consecutive_resyncs++; } else { last_catch_up = catch_up_cycles; consecutive_resyncs = 0; } if (consecutive_resyncs < 3) { if (MF_DBGLEVEL >= 3) Dbprintf("Lost sync in cycle %d. nt_distance=%d. Consecutive Resyncs = %d. Trying one time catch up...\n", i, -catch_up_cycles, consecutive_resyncs); } 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); } continue; } 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)) { catch_up_cycles = 8; // the PRNG is delayed by 8 cycles due to the NAC (4Bits = 0x05 encrypted) transfer 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 } led_on = !led_on; if(led_on) LED_B_ON(); else LED_B_OFF(); par_list[nt_diff] = SwapBits(par[0], 8); ks_list[nt_diff] = receivedAnswer[0] ^ 0x05; // Test if the information is complete if (nt_diff == 0x07) { isOK = 1; break; } nt_diff = (nt_diff + 1) & 0x07; mf_nr_ar[3] = (mf_nr_ar[3] & 0x1F) | (nt_diff << 5); par[0] = par_low; } else { if (nt_diff == 0 && first_try) { par[0]++; } else { par[0] = ((par[0] & 0x1F) + 1) | par_low; } } } mf_nr_ar[3] &= 0x1F; byte_t buf[28]; memcpy(buf + 0, uid, 4); num_to_bytes(nt, 4, buf + 4); memcpy(buf + 8, par_list, 8); memcpy(buf + 16, ks_list, 8); memcpy(buf + 24, mf_nr_ar, 4); cmd_send(CMD_ACK,isOK,0,0,buf,28); // Thats it... FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); LEDsoff(); iso14a_set_tracing(FALSE); } /** *MIFARE 1K simulate. * *@param flags : * FLAG_INTERACTIVE - In interactive mode, we are expected to finish the operation with an ACK * 4B_FLAG_UID_IN_DATA - means that there is a 4-byte UID in the data-section, we're expected to use that * 7B_FLAG_UID_IN_DATA - means that there is a 7-byte UID in the data-section, we're expected to use that * FLAG_NR_AR_ATTACK - means we should collect NR_AR responses for bruteforcing later *@param exitAfterNReads, exit simulation after n blocks have been read, 0 is inifite */ void Mifare1ksim(uint8_t flags, uint8_t exitAfterNReads, uint8_t arg2, uint8_t *datain) { int cardSTATE = MFEMUL_NOFIELD; int _7BUID = 0; int vHf = 0; // in mV int res; uint32_t selTimer = 0; uint32_t authTimer = 0; uint16_t len = 0; uint8_t cardWRBL = 0; uint8_t cardAUTHSC = 0; uint8_t cardAUTHKEY = 0xff; // no authentication uint32_t cardRr = 0; uint32_t cuid = 0; //uint32_t rn_enc = 0; uint32_t ans = 0; uint32_t cardINTREG = 0; uint8_t cardINTBLOCK = 0; struct Crypto1State mpcs = {0, 0}; struct Crypto1State *pcs; pcs = &mpcs; uint32_t numReads = 0;//Counts numer of times reader read a block uint8_t* receivedCmd = get_bigbufptr_recvcmdbuf(); uint8_t* receivedCmd_par = receivedCmd + MAX_FRAME_SIZE; uint8_t* response = get_bigbufptr_recvrespbuf(); uint8_t* response_par = response + MAX_FRAME_SIZE; uint8_t rATQA[] = {0x04, 0x00}; // Mifare classic 1k 4BUID uint8_t rUIDBCC1[] = {0xde, 0xad, 0xbe, 0xaf, 0x62}; uint8_t rUIDBCC2[] = {0xde, 0xad, 0xbe, 0xaf, 0x62}; // !!! uint8_t rSAK[] = {0x08, 0xb6, 0xdd}; uint8_t rSAK1[] = {0x04, 0xda, 0x17}; uint8_t rAUTH_NT[] = {0x01, 0x02, 0x03, 0x04}; uint8_t rAUTH_AT[] = {0x00, 0x00, 0x00, 0x00}; //Here, we collect UID,NT,AR,NR,UID2,NT2,AR2,NR2 // This can be used in a reader-only attack. // (it can also be retrieved via 'hf 14a list', but hey... uint32_t ar_nr_responses[] = {0,0,0,0,0,0,0,0}; uint8_t ar_nr_collected = 0; // clear trace iso14a_clear_trace(); iso14a_set_tracing(TRUE); // Authenticate response - nonce uint32_t nonce = bytes_to_num(rAUTH_NT, 4); //-- Determine the UID // Can be set from emulator memory, incoming data // and can be 7 or 4 bytes long if (flags & FLAG_4B_UID_IN_DATA) { // 4B uid comes from data-portion of packet memcpy(rUIDBCC1,datain,4); rUIDBCC1[4] = rUIDBCC1[0] ^ rUIDBCC1[1] ^ rUIDBCC1[2] ^ rUIDBCC1[3]; } else if (flags & FLAG_7B_UID_IN_DATA) { // 7B uid comes from data-portion of packet memcpy(&rUIDBCC1[1],datain,3); memcpy(rUIDBCC2, datain+3, 4); _7BUID = true; } else { // get UID from emul memory emlGetMemBt(receivedCmd, 7, 1); _7BUID = !(receivedCmd[0] == 0x00); if (!_7BUID) { // ---------- 4BUID emlGetMemBt(rUIDBCC1, 0, 4); } else { // ---------- 7BUID emlGetMemBt(&rUIDBCC1[1], 0, 3); emlGetMemBt(rUIDBCC2, 3, 4); } } /* * Regardless of what method was used to set the UID, set fifth byte and modify * the ATQA for 4 or 7-byte UID */ rUIDBCC1[4] = rUIDBCC1[0] ^ rUIDBCC1[1] ^ rUIDBCC1[2] ^ rUIDBCC1[3]; if (_7BUID) { rATQA[0] = 0x44; rUIDBCC1[0] = 0x88; rUIDBCC2[4] = rUIDBCC2[0] ^ rUIDBCC2[1] ^ rUIDBCC2[2] ^ rUIDBCC2[3]; } // We need to listen to the high-frequency, peak-detected path. iso14443a_setup(FPGA_HF_ISO14443A_TAGSIM_LISTEN); if (MF_DBGLEVEL >= 1) { if (!_7BUID) { 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]); } } bool finished = FALSE; while (!BUTTON_PRESS() && !finished) { WDT_HIT(); // find reader field // Vref = 3300mV, and an 10:1 voltage divider on the input // can measure voltages up to 33000 mV if (cardSTATE == MFEMUL_NOFIELD) { vHf = (33000 * AvgAdc(ADC_CHAN_HF)) >> 10; if (vHf > MF_MINFIELDV) { cardSTATE_TO_IDLE(); LED_A_ON(); } } if(cardSTATE == MFEMUL_NOFIELD) continue; //Now, get data res = EmGetCmd(receivedCmd, &len, receivedCmd_par); if (res == 2) { //Field is off! cardSTATE = MFEMUL_NOFIELD; LEDsoff(); continue; } else if (res == 1) { break; //return value 1 means button press } // REQ or WUP request in ANY state and WUP in HALTED state if (len == 1 && ((receivedCmd[0] == 0x26 && cardSTATE != MFEMUL_HALTED) || receivedCmd[0] == 0x52)) { selTimer = GetTickCount(); EmSendCmdEx(rATQA, sizeof(rATQA), (receivedCmd[0] == 0x52)); cardSTATE = MFEMUL_SELECT1; // init crypto block LED_B_OFF(); LED_C_OFF(); crypto1_destroy(pcs); cardAUTHKEY = 0xff; continue; } switch (cardSTATE) { case MFEMUL_NOFIELD: case MFEMUL_HALTED: case MFEMUL_IDLE:{ LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE); break; } case MFEMUL_SELECT1:{ // select all if (len == 2 && (receivedCmd[0] == 0x93 && receivedCmd[1] == 0x20)) { if (MF_DBGLEVEL >= 4) Dbprintf("SELECT ALL received"); EmSendCmd(rUIDBCC1, sizeof(rUIDBCC1)); break; } if (MF_DBGLEVEL >= 4 && len == 9 && receivedCmd[0] == 0x93 && receivedCmd[1] == 0x70 ) { Dbprintf("SELECT %02x%02x%02x%02x received",receivedCmd[2],receivedCmd[3],receivedCmd[4],receivedCmd[5]); } // select card if (len == 9 && (receivedCmd[0] == 0x93 && receivedCmd[1] == 0x70 && memcmp(&receivedCmd[2], rUIDBCC1, 4) == 0)) { EmSendCmd(_7BUID?rSAK1:rSAK, _7BUID?sizeof(rSAK1):sizeof(rSAK)); cuid = bytes_to_num(rUIDBCC1, 4); if (!_7BUID) { cardSTATE = MFEMUL_WORK; LED_B_ON(); if (MF_DBGLEVEL >= 4) Dbprintf("--> WORK. anticol1 time: %d", GetTickCount() - selTimer); break; } else { cardSTATE = MFEMUL_SELECT2; } } break; } case MFEMUL_AUTH1:{ if( len != 8) { cardSTATE_TO_IDLE(); LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE); break; } uint32_t ar = bytes_to_num(receivedCmd, 4); uint32_t nr = bytes_to_num(&receivedCmd[4], 4); //Collect AR/NR if(ar_nr_collected < 2){ if(ar_nr_responses[2] != ar) {// Avoid duplicates... probably not necessary, ar should vary. ar_nr_responses[ar_nr_collected*4] = cuid; ar_nr_responses[ar_nr_collected*4+1] = nonce; ar_nr_responses[ar_nr_collected*4+2] = ar; ar_nr_responses[ar_nr_collected*4+3] = nr; ar_nr_collected++; } } // --- crypto crypto1_word(pcs, ar , 1); cardRr = nr ^ crypto1_word(pcs, 0, 0); // test if auth OK if (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.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE); break; } ans = prng_successor(nonce, 96) ^ crypto1_word(pcs, 0, 0); num_to_bytes(ans, 4, rAUTH_AT); // --- crypto EmSendCmd(rAUTH_AT, sizeof(rAUTH_AT)); LED_C_ON(); cardSTATE = MFEMUL_WORK; 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:{ if (!len) { LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE); break; } if (len == 2 && (receivedCmd[0] == 0x95 && receivedCmd[1] == 0x20)) { EmSendCmd(rUIDBCC2, sizeof(rUIDBCC2)); break; } // select 2 card if (len == 9 && (receivedCmd[0] == 0x95 && receivedCmd[1] == 0x70 && memcmp(&receivedCmd[2], rUIDBCC2, 4) == 0)) { EmSendCmd(rSAK, sizeof(rSAK)); cuid = bytes_to_num(rUIDBCC2, 4); cardSTATE = MFEMUL_WORK; LED_B_ON(); if (MF_DBGLEVEL >= 4) Dbprintf("--> WORK. anticol2 time: %d", GetTickCount() - selTimer); break; } // i guess there is a command). go into the work state. if (len != 4) { LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE); break; } cardSTATE = MFEMUL_WORK; //goto lbWORK; //intentional fall-through to the next case-stmt } case MFEMUL_WORK:{ if (len == 0) { LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE); break; } bool encrypted_data = (cardAUTHKEY != 0xFF) ; if(encrypted_data) { // decrypt seqence mf_crypto1_decrypt(pcs, receivedCmd, len); } if (len == 4 && (receivedCmd[0] == 0x60 || receivedCmd[0] == 0x61)) { authTimer = GetTickCount(); cardAUTHSC = receivedCmd[1] / 4; // received block num cardAUTHKEY = receivedCmd[0] - 0x60; crypto1_destroy(pcs);//Added by martin crypto1_create(pcs, emlGetKey(cardAUTHSC, cardAUTHKEY)); if (!encrypted_data) { // first authentication 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 >= 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); } EmSendCmd(rAUTH_AT, sizeof(rAUTH_AT)); //Dbprintf("Sending rAUTH %02x%02x%02x%02x", rAUTH_AT[0],rAUTH_AT[1],rAUTH_AT[2],rAUTH_AT[3]); cardSTATE = MFEMUL_AUTH1; break; } // rule 13 of 7.5.3. in ISO 14443-4. chaining shall be continued // BUT... ACK --> NACK if (len == 1 && receivedCmd[0] == CARD_ACK) { EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA)); break; } // rule 12 of 7.5.3. in ISO 14443-4. R(NAK) --> R(ACK) if (len == 1 && receivedCmd[0] == CARD_NACK_NA) { EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK)); break; } if(len != 4) { LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE); break; } if(receivedCmd[0] == 0x30 // read block || receivedCmd[0] == 0xA0 // write block || 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)); if (MF_DBGLEVEL >= 2) Dbprintf("Reader tried to operate (0x%02) on out of range block: %d (0x%02x), nacking",receivedCmd[0],receivedCmd[1],receivedCmd[1]); break; } if (receivedCmd[1] / 4 != cardAUTHSC) { EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA)); if (MF_DBGLEVEL >= 2) Dbprintf("Reader tried to operate (0x%02) on block (0x%02x) not authenticated for (0x%02x), nacking",receivedCmd[0],receivedCmd[1],cardAUTHSC); break; } } // read block if (receivedCmd[0] == 0x30) { if (MF_DBGLEVEL >= 4) { Dbprintf("Reader reading block %d (0x%02x)",receivedCmd[1],receivedCmd[1]); } emlGetMem(response, receivedCmd[1], 1); AppendCrc14443a(response, 16); mf_crypto1_encrypt(pcs, response, 18, response_par); EmSendCmdPar(response, 18, response_par); numReads++; if(exitAfterNReads > 0 && numReads == exitAfterNReads) { Dbprintf("%d reads done, exiting", numReads); finished = true; } break; } // write block if (receivedCmd[0] == 0xA0) { 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]; break; } // increment, decrement, restore if (receivedCmd[0] == 0xC0 || receivedCmd[0] == 0xC1 || receivedCmd[0] == 0xC2) { 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)); break; } EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK)); if (receivedCmd[0] == 0xC1) cardSTATE = MFEMUL_INTREG_INC; if (receivedCmd[0] == 0xC0) cardSTATE = MFEMUL_INTREG_DEC; if (receivedCmd[0] == 0xC2) cardSTATE = MFEMUL_INTREG_REST; cardWRBL = receivedCmd[1]; break; } // transfer if (receivedCmd[0] == 0xB0) { 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 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK)); break; } // halt if (receivedCmd[0] == 0x50 && receivedCmd[1] == 0x00) { LED_B_OFF(); LED_C_OFF(); cardSTATE = MFEMUL_HALTED; if (MF_DBGLEVEL >= 4) Dbprintf("--> HALTED. Selected time: %d ms", GetTickCount() - selTimer); LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE); break; } // RATS if (receivedCmd[0] == 0xe0) {//RATS EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA)); break; } // command not allowed if (MF_DBGLEVEL >= 4) Dbprintf("Received command not allowed, nacking"); EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA)); break; } case MFEMUL_WRITEBL2:{ if (len == 18){ mf_crypto1_decrypt(pcs, receivedCmd, len); emlSetMem(receivedCmd, cardWRBL, 1); EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK)); cardSTATE = MFEMUL_WORK; } else { cardSTATE_TO_IDLE(); LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE); } break; } case MFEMUL_INTREG_INC:{ mf_crypto1_decrypt(pcs, receivedCmd, len); memcpy(&ans, receivedCmd, 4); if (emlGetValBl(&cardINTREG, &cardINTBLOCK, cardWRBL)) { EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA)); cardSTATE_TO_IDLE(); break; } LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE); cardINTREG = cardINTREG + ans; cardSTATE = MFEMUL_WORK; break; } case MFEMUL_INTREG_DEC:{ mf_crypto1_decrypt(pcs, receivedCmd, len); memcpy(&ans, receivedCmd, 4); if (emlGetValBl(&cardINTREG, &cardINTBLOCK, cardWRBL)) { EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA)); cardSTATE_TO_IDLE(); break; } LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE); cardINTREG = cardINTREG - ans; cardSTATE = MFEMUL_WORK; break; } case MFEMUL_INTREG_REST:{ mf_crypto1_decrypt(pcs, receivedCmd, len); memcpy(&ans, receivedCmd, 4); if (emlGetValBl(&cardINTREG, &cardINTBLOCK, cardWRBL)) { EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA)); cardSTATE_TO_IDLE(); break; } LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE); cardSTATE = MFEMUL_WORK; break; } } } FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); LEDsoff(); if(flags & FLAG_INTERACTIVE)// Interactive mode flag, means we need to send ACK { //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 %08x %08x", ar_nr_responses[0], // UID ar_nr_responses[1], //NT ar_nr_responses[2], //AR1 ar_nr_responses[3], //NR1 ar_nr_responses[6], //AR2 ar_nr_responses[7] //NR2 ); } else { Dbprintf("Failed to obtain two AR/NR pairs!"); if(ar_nr_collected >0) { 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 ar_nr_responses[3] //NR1 ); } } } if (MF_DBGLEVEL >= 1) Dbprintf("Emulator stopped. Tracing: %d trace length: %d ", tracing, traceLen); } //----------------------------------------------------------------------------- // MIFARE sniffer. // //----------------------------------------------------------------------------- void RAMFUNC SniffMifare(uint8_t param) { // param: // bit 0 - trigger from first card answer // bit 1 - trigger from first reader 7-bit request // C(red) A(yellow) B(green) LEDsoff(); // init trace buffer 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. // So 32 should be enough! uint8_t *receivedCmd = BigBuf_get_addr() + RECV_CMD_OFFSET; uint8_t *receivedCmdPar = BigBuf_get_addr() + RECV_CMD_PAR_OFFSET; // The response (tag -> reader) that we're receiving. uint8_t *receivedResponse = BigBuf_get_addr() + RECV_RESP_OFFSET; uint8_t *receivedResponsePar = BigBuf_get_addr() + RECV_RESP_PAR_OFFSET; // As we receive stuff, we copy it from receivedCmd or receivedResponse // into trace, along with its length and other annotations. //uint8_t *trace = (uint8_t *)BigBuf; // The DMA buffer, used to stream samples from the FPGA uint8_t *dmaBuf = BigBuf_get_addr() + DMA_BUFFER_OFFSET; uint8_t *data = dmaBuf; uint8_t previous_data = 0; int maxDataLen = 0; int dataLen = 0; bool ReaderIsActive = FALSE; bool TagIsActive = FALSE; iso14443a_setup(FPGA_HF_ISO14443A_SNIFFER); // Set up the demodulator for tag -> reader responses. DemodInit(receivedResponse, receivedResponsePar); // Set up the demodulator for the reader -> tag commands UartInit(receivedCmd, receivedCmdPar); // Setup for the DMA. FpgaSetupSscDma((uint8_t *)dmaBuf, DMA_BUFFER_SIZE); // set transfer address and number of bytes. Start transfer. LED_D_OFF(); // init sniffer MfSniffInit(); // And now we loop, receiving samples. for(uint32_t sniffCounter = 0; TRUE; ) { if(BUTTON_PRESS()) { DbpString("cancelled by button"); break; } LED_A_ON(); WDT_HIT(); if ((sniffCounter & 0x0000FFFF) == 0) { // from time to time // check if a transaction is completed (timeout after 2000ms). // if yes, stop the DMA transfer and send what we have so far to the client if (MfSniffSend(2000)) { // Reset everything - we missed some sniffed data anyway while the DMA was stopped sniffCounter = 0; data = dmaBuf; maxDataLen = 0; ReaderIsActive = FALSE; TagIsActive = FALSE; FpgaSetupSscDma((uint8_t *)dmaBuf, DMA_BUFFER_SIZE); // set transfer address and number of bytes. Start transfer. } } int register readBufDataP = data - dmaBuf; // number of bytes we have processed so far int register dmaBufDataP = DMA_BUFFER_SIZE - AT91C_BASE_PDC_SSC->PDC_RCR; // number of bytes already transferred if (readBufDataP <= dmaBufDataP){ // we are processing the same block of data which is currently being transferred dataLen = dmaBufDataP - readBufDataP; // number of bytes still to be processed } else { dataLen = DMA_BUFFER_SIZE - readBufDataP + dmaBufDataP; // number of bytes still to be processed } // test for length of buffer if(dataLen > maxDataLen) { // we are more behind than ever... maxDataLen = dataLen; if(dataLen > 400) { Dbprintf("blew circular buffer! dataLen=0x%x", dataLen); break; } } if(dataLen < 1) continue; // primary buffer was stopped ( <-- we lost data! if (!AT91C_BASE_PDC_SSC->PDC_RCR) { AT91C_BASE_PDC_SSC->PDC_RPR = (uint32_t) dmaBuf; AT91C_BASE_PDC_SSC->PDC_RCR = DMA_BUFFER_SIZE; Dbprintf("RxEmpty ERROR!!! data length:%d", dataLen); // temporary } // secondary buffer sets as primary, secondary buffer was stopped if (!AT91C_BASE_PDC_SSC->PDC_RNCR) { AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) dmaBuf; AT91C_BASE_PDC_SSC->PDC_RNCR = DMA_BUFFER_SIZE; } LED_A_OFF(); if (sniffCounter & 0x01) { if(!TagIsActive) { // no need to try decoding tag data if the reader is sending uint8_t readerdata = (previous_data & 0xF0) | (*data >> 4); if(MillerDecoding(readerdata, (sniffCounter-1)*4)) { LED_C_INV(); if (MfSniffLogic(receivedCmd, Uart.len, Uart.parity, Uart.bitCount, TRUE)) break; /* And ready to receive another command. */ UartReset(); /* And also reset the demod code */ DemodReset(); } ReaderIsActive = (Uart.state != STATE_UNSYNCD); } if(!ReaderIsActive) { // no need to try decoding tag data if the reader is sending uint8_t tagdata = (previous_data << 4) | (*data & 0x0F); if(ManchesterDecoding(tagdata, 0, (sniffCounter-1)*4)) { LED_C_INV(); if (MfSniffLogic(receivedResponse, Demod.len, Demod.parity, Demod.bitCount, FALSE)) break; // And ready to receive another response. DemodReset(); } TagIsActive = (Demod.state != DEMOD_UNSYNCD); } } previous_data = *data; sniffCounter++; data++; if(data == dmaBuf + DMA_BUFFER_SIZE) { data = dmaBuf; } } // main cycle DbpString("COMMAND FINISHED"); FpgaDisableSscDma(); MfSniffEnd(); Dbprintf("maxDataLen=%x, Uart.state=%x, Uart.len=%x", maxDataLen, Uart.state, Uart.len); LEDsoff(); }