//----------------------------------------------------------------------------- // Jonathan Westhues, split Nov 2006 // Modified by Greg Jones, Jan 2009 // Modified by Adrian Dabrowski "atrox", Mar-Sept 2010,Oct 2011 // Modified by piwi, Oct 2018 // // 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 15693. This includes both the reader software and // the `fake tag' modes. //----------------------------------------------------------------------------- // The ISO 15693 describes two transmission modes from reader to tag, and four // transmission modes from tag to reader. As of Oct 2018 this code supports // both reader modes and the high speed variant with one subcarrier from card to reader. // As long as the card fully support ISO 15693 this is no problem, since the // reader chooses both data rates, but some non-standard tags do not. // For card simulation, the code supports both high and low speed modes with one subcarrier. // // VCD (reader) -> VICC (tag) // 1 out of 256: // data rate: 1,66 kbit/s (fc/8192) // used for long range // 1 out of 4: // data rate: 26,48 kbit/s (fc/512) // used for short range, high speed // // VICC (tag) -> VCD (reader) // Modulation: // ASK / one subcarrier (423,75 khz) // FSK / two subcarriers (423,75 khz && 484,28 khz) // Data Rates / Modes: // low ASK: 6,62 kbit/s // low FSK: 6.67 kbit/s // high ASK: 26,48 kbit/s // high FSK: 26,69 kbit/s //----------------------------------------------------------------------------- // Random Remarks: // *) UID is always used "transmission order" (LSB), which is reverse to display order // TODO / BUGS / ISSUES: // *) signal decoding is unable to detect collisions. // *) add anti-collision support for inventory-commands // *) read security status of a block // *) sniffing and simulation do not support two subcarrier modes. // *) remove or refactor code under "deprecated" // *) document all the functions #include "iso15693.h" #include "proxmark3.h" #include "util.h" #include "apps.h" #include "string.h" #include "iso15693tools.h" #include "protocols.h" #include "usb_cdc.h" #include "BigBuf.h" #include "fpgaloader.h" #define arraylen(x) (sizeof(x)/sizeof((x)[0])) // Delays in SSP_CLK ticks. // SSP_CLK runs at 13,56MHz / 32 = 423.75kHz when simulating a tag #define DELAY_READER_TO_ARM 8 #define DELAY_ARM_TO_READER 0 //SSP_CLK runs at 13.56MHz / 4 = 3,39MHz when acting as reader. All values should be multiples of 16 #define DELAY_ARM_TO_TAG 16 #define DELAY_TAG_TO_ARM 32 //SSP_CLK runs at 13.56MHz / 4 = 3,39MHz when snooping. All values should be multiples of 16 #define DELAY_TAG_TO_ARM_SNOOP 32 #define DELAY_READER_TO_ARM_SNOOP 32 // times in samples @ 212kHz when acting as reader //#define ISO15693_READER_TIMEOUT 80 // 80/212kHz = 378us, nominal t1_max=313,9us #define ISO15693_READER_TIMEOUT 330 // 330/212kHz = 1558us, should be even enough for iClass tags responding to ACTALL #define ISO15693_READER_TIMEOUT_WRITE 4700 // 4700/212kHz = 22ms, nominal 20ms static int DEBUG = 0; /////////////////////////////////////////////////////////////////////// // ISO 15693 Part 2 - Air Interface // This section basically contains transmission and receiving of bits /////////////////////////////////////////////////////////////////////// // buffers #define ISO15693_DMA_BUFFER_SIZE 256 // must be a power of 2 #define ISO15693_MAX_RESPONSE_LENGTH 36 // allows read single block with the maximum block size of 256bits. Read multiple blocks not supported yet #define ISO15693_MAX_COMMAND_LENGTH 45 // allows write single block with the maximum block size of 256bits. Write multiple blocks not supported yet // specific LogTrace function for ISO15693: the duration needs to be scaled because otherwise it won't fit into a uint16_t bool LogTrace_ISO15693(const uint8_t *btBytes, uint16_t iLen, uint32_t timestamp_start, uint32_t timestamp_end, uint8_t *parity, bool readerToTag) { uint32_t duration = timestamp_end - timestamp_start; duration /= 32; timestamp_end = timestamp_start + duration; return LogTrace(btBytes, iLen, timestamp_start, timestamp_end, parity, readerToTag); } // --------------------------- // Signal Processing // --------------------------- // prepare data using "1 out of 4" code for later transmission // resulting data rate is 26.48 kbit/s (fc/512) // cmd ... data // n ... length of data void CodeIso15693AsReader(uint8_t *cmd, int n) { ToSendReset(); // SOF for 1of4 ToSend[++ToSendMax] = 0x84; //10000100 // data for (int i = 0; i < n; i++) { for (int j = 0; j < 8; j += 2) { int these = (cmd[i] >> j) & 0x03; switch(these) { case 0: ToSend[++ToSendMax] = 0x40; //01000000 break; case 1: ToSend[++ToSendMax] = 0x10; //00010000 break; case 2: ToSend[++ToSendMax] = 0x04; //00000100 break; case 3: ToSend[++ToSendMax] = 0x01; //00000001 break; } } } // EOF ToSend[++ToSendMax] = 0x20; //0010 + 0000 padding ToSendMax++; } // Encode EOF only static void CodeIso15693AsReaderEOF() { ToSendReset(); ToSend[++ToSendMax] = 0x20; ToSendMax++; } // encode data using "1 out of 256" scheme // data rate is 1,66 kbit/s (fc/8192) // is designed for more robust communication over longer distances static void CodeIso15693AsReader256(uint8_t *cmd, int n) { ToSendReset(); // SOF for 1of256 ToSend[++ToSendMax] = 0x81; //10000001 // data for(int i = 0; i < n; i++) { for (int j = 0; j <= 255; j++) { if (cmd[i] == j) { ToSendStuffBit(0); ToSendStuffBit(1); } else { ToSendStuffBit(0); ToSendStuffBit(0); } } } // EOF ToSend[++ToSendMax] = 0x20; //0010 + 0000 padding ToSendMax++; } // static uint8_t encode4Bits(const uint8_t b) { // uint8_t c = b & 0xF; // // OTA, the least significant bits first // // The columns are // // 1 - Bit value to send // // 2 - Reversed (big-endian) // // 3 - Manchester Encoded // // 4 - Hex values // switch(c){ // // 1 2 3 4 // case 15: return 0x55; // 1111 -> 1111 -> 01010101 -> 0x55 // case 14: return 0x95; // 1110 -> 0111 -> 10010101 -> 0x95 // case 13: return 0x65; // 1101 -> 1011 -> 01100101 -> 0x65 // case 12: return 0xa5; // 1100 -> 0011 -> 10100101 -> 0xa5 // case 11: return 0x59; // 1011 -> 1101 -> 01011001 -> 0x59 // case 10: return 0x99; // 1010 -> 0101 -> 10011001 -> 0x99 // case 9: return 0x69; // 1001 -> 1001 -> 01101001 -> 0x69 // case 8: return 0xa9; // 1000 -> 0001 -> 10101001 -> 0xa9 // case 7: return 0x56; // 0111 -> 1110 -> 01010110 -> 0x56 // case 6: return 0x96; // 0110 -> 0110 -> 10010110 -> 0x96 // case 5: return 0x66; // 0101 -> 1010 -> 01100110 -> 0x66 // case 4: return 0xa6; // 0100 -> 0010 -> 10100110 -> 0xa6 // case 3: return 0x5a; // 0011 -> 1100 -> 01011010 -> 0x5a // case 2: return 0x9a; // 0010 -> 0100 -> 10011010 -> 0x9a // case 1: return 0x6a; // 0001 -> 1000 -> 01101010 -> 0x6a // default: return 0xaa; // 0000 -> 0000 -> 10101010 -> 0xaa // } // } static const uint8_t encode_4bits[16] = { 0xaa, 0x6a, 0x9a, 0x5a, 0xa6, 0x66, 0x96, 0x56, 0xa9, 0x69, 0x99, 0x59, 0xa5, 0x65, 0x95, 0x55 }; void CodeIso15693AsTag(uint8_t *cmd, size_t len) { /* * SOF comprises 3 parts; * * An unmodulated time of 56.64 us * * 24 pulses of 423.75 kHz (fc/32) * * A logic 1, which starts with an unmodulated time of 18.88us * followed by 8 pulses of 423.75kHz (fc/32) * * EOF comprises 3 parts: * - A logic 0 (which starts with 8 pulses of fc/32 followed by an unmodulated * time of 18.88us. * - 24 pulses of fc/32 * - An unmodulated time of 56.64 us * * A logic 0 starts with 8 pulses of fc/32 * followed by an unmodulated time of 256/fc (~18,88us). * * A logic 0 starts with unmodulated time of 256/fc (~18,88us) followed by * 8 pulses of fc/32 (also 18.88us) * * A bit here becomes 8 pulses of fc/32. Therefore: * The SOF can be written as 00011101 = 0x1D * The EOF can be written as 10111000 = 0xb8 * A logic 1 is 01 * A logic 0 is 10 * * */ ToSendReset(); // SOF ToSend[++ToSendMax] = 0x1D; // 00011101 // data for (int i = 0; i < len; i++) { ToSend[++ToSendMax] = encode_4bits[cmd[i] & 0xF]; ToSend[++ToSendMax] = encode_4bits[cmd[i] >> 4]; } // EOF ToSend[++ToSendMax] = 0xB8; // 10111000 ToSendMax++; } // Transmit the command (to the tag) that was placed in cmd[]. void TransmitTo15693Tag(const uint8_t *cmd, int len, uint32_t *start_time) { FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER | FPGA_HF_READER_MODE_SEND_FULL_MOD); if (*start_time < DELAY_ARM_TO_TAG) { *start_time = DELAY_ARM_TO_TAG; } *start_time = (*start_time - DELAY_ARM_TO_TAG) & 0xfffffff0; if (GetCountSspClk() > *start_time) { // we may miss the intended time *start_time = (GetCountSspClk() + 16) & 0xfffffff0; // next possible time } while (GetCountSspClk() < *start_time) /* wait */ ; LED_B_ON(); for (int c = 0; c < len; c++) { uint8_t data = cmd[c]; for (int i = 0; i < 8; i++) { uint16_t send_word = (data & 0x80) ? 0xffff : 0x0000; while (!(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY))) ; AT91C_BASE_SSC->SSC_THR = send_word; while (!(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY))) ; AT91C_BASE_SSC->SSC_THR = send_word; data <<= 1; } WDT_HIT(); } LED_B_OFF(); *start_time = *start_time + DELAY_ARM_TO_TAG; } //----------------------------------------------------------------------------- // Transmit the tag response (to the reader) that was placed in cmd[]. //----------------------------------------------------------------------------- void TransmitTo15693Reader(const uint8_t *cmd, size_t len, uint32_t *start_time, uint32_t slot_time, bool slow) { // don't use the FPGA_HF_SIMULATOR_MODULATE_424K_8BIT minor mode. It would spoil GetCountSspClk() FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_SIMULATOR | FPGA_HF_SIMULATOR_MODULATE_424K); uint32_t modulation_start_time = *start_time - DELAY_ARM_TO_READER + 3 * 8; // no need to transfer the unmodulated start of SOF while (GetCountSspClk() > (modulation_start_time & 0xfffffff8) + 3) { // we will miss the intended time if (slot_time) { modulation_start_time += slot_time; // use next available slot } else { modulation_start_time = (modulation_start_time & 0xfffffff8) + 8; // next possible time } } while (GetCountSspClk() < (modulation_start_time & 0xfffffff8)) /* wait */ ; uint8_t shift_delay = modulation_start_time & 0x00000007; *start_time = modulation_start_time + DELAY_ARM_TO_READER - 3 * 8; LED_C_ON(); uint8_t bits_to_shift = 0x00; uint8_t bits_to_send = 0x00; for (size_t c = 0; c < len; c++) { for (int i = (c==0?4:7); i >= 0; i--) { uint8_t cmd_bits = ((cmd[c] >> i) & 0x01) ? 0xff : 0x00; for (int j = 0; j < (slow?4:1); ) { if (AT91C_BASE_SSC->SSC_SR & AT91C_SSC_TXRDY) { bits_to_send = bits_to_shift << (8 - shift_delay) | cmd_bits >> shift_delay; AT91C_BASE_SSC->SSC_THR = bits_to_send; bits_to_shift = cmd_bits; j++; } } } WDT_HIT(); } // send the remaining bits, padded with 0: bits_to_send = bits_to_shift << (8 - shift_delay); for ( ; ; ) { if (AT91C_BASE_SSC->SSC_SR & AT91C_SSC_TXRDY) { AT91C_BASE_SSC->SSC_THR = bits_to_send; break; } } LED_C_OFF(); } //============================================================================= // An ISO 15693 decoder for tag responses (one subcarrier only). // Uses cross correlation to identify each bit and EOF. // This function is called 8 times per bit (every 2 subcarrier cycles). // Subcarrier frequency fs is 424kHz, 1/fs = 2,36us, // i.e. function is called every 4,72us // LED handling: // LED C -> ON once we have received the SOF and are expecting the rest. // LED C -> OFF once we have received EOF or are unsynced // // Returns: true if we received a EOF // false if we are still waiting for some more //============================================================================= #define NOISE_THRESHOLD 80 // don't try to correlate noise #define MAX_PREVIOUS_AMPLITUDE (-1 - NOISE_THRESHOLD) typedef struct DecodeTag { enum { STATE_TAG_SOF_LOW, STATE_TAG_SOF_RISING_EDGE, STATE_TAG_SOF_HIGH, STATE_TAG_SOF_HIGH_END, STATE_TAG_RECEIVING_DATA, STATE_TAG_EOF, STATE_TAG_EOF_TAIL } state; int bitCount; int posCount; enum { LOGIC0, LOGIC1, SOF_PART1, SOF_PART2 } lastBit; uint16_t shiftReg; uint16_t max_len; uint8_t *output; int len; int sum1, sum2; int threshold_sof; int threshold_half; uint16_t previous_amplitude; } DecodeTag_t; static int inline __attribute__((always_inline)) Handle15693SamplesFromTag(uint16_t amplitude, DecodeTag_t *DecodeTag) { switch (DecodeTag->state) { case STATE_TAG_SOF_LOW: // waiting for a rising edge if (amplitude > NOISE_THRESHOLD + DecodeTag->previous_amplitude) { if (DecodeTag->posCount > 10) { DecodeTag->threshold_sof = amplitude - DecodeTag->previous_amplitude; // to be divided by 2 DecodeTag->threshold_half = 0; DecodeTag->state = STATE_TAG_SOF_RISING_EDGE; } else { DecodeTag->posCount = 0; } } else { DecodeTag->posCount++; DecodeTag->previous_amplitude = amplitude; } break; case STATE_TAG_SOF_RISING_EDGE: if (amplitude > DecodeTag->threshold_sof + DecodeTag->previous_amplitude) { // edge still rising if (amplitude > DecodeTag->threshold_sof + DecodeTag->threshold_sof) { // steeper edge, take this as time reference DecodeTag->posCount = 1; } else { DecodeTag->posCount = 2; } DecodeTag->threshold_sof = (amplitude - DecodeTag->previous_amplitude) / 2; } else { DecodeTag->posCount = 2; DecodeTag->threshold_sof = DecodeTag->threshold_sof/2; } // DecodeTag->posCount = 2; DecodeTag->state = STATE_TAG_SOF_HIGH; break; case STATE_TAG_SOF_HIGH: // waiting for 10 times high. Take average over the last 8 if (amplitude > DecodeTag->threshold_sof) { DecodeTag->posCount++; if (DecodeTag->posCount > 2) { DecodeTag->threshold_half += amplitude; // keep track of average high value } if (DecodeTag->posCount == 10) { DecodeTag->threshold_half >>= 2; // (4 times 1/2 average) DecodeTag->state = STATE_TAG_SOF_HIGH_END; } } else { // high phase was too short DecodeTag->posCount = 1; DecodeTag->previous_amplitude = amplitude; DecodeTag->state = STATE_TAG_SOF_LOW; } break; case STATE_TAG_SOF_HIGH_END: // check for falling edge if (DecodeTag->posCount == 13 && amplitude < DecodeTag->threshold_sof) { DecodeTag->lastBit = SOF_PART1; // detected 1st part of SOF (12 samples low and 12 samples high) DecodeTag->shiftReg = 0; DecodeTag->bitCount = 0; DecodeTag->len = 0; DecodeTag->sum1 = amplitude; DecodeTag->sum2 = 0; DecodeTag->posCount = 2; DecodeTag->state = STATE_TAG_RECEIVING_DATA; // FpgaDisableTracing(); // DEBUGGING // Dbprintf("amplitude = %d, threshold_sof = %d, threshold_half/4 = %d, previous_amplitude = %d", // amplitude, // DecodeTag->threshold_sof, // DecodeTag->threshold_half/4, // DecodeTag->previous_amplitude); // DEBUGGING LED_C_ON(); } else { DecodeTag->posCount++; if (DecodeTag->posCount > 13) { // high phase too long DecodeTag->posCount = 0; DecodeTag->previous_amplitude = amplitude; DecodeTag->state = STATE_TAG_SOF_LOW; LED_C_OFF(); } } break; case STATE_TAG_RECEIVING_DATA: // FpgaDisableTracing(); // DEBUGGING // Dbprintf("amplitude = %d, threshold_sof = %d, threshold_half/4 = %d, previous_amplitude = %d", // amplitude, // DecodeTag->threshold_sof, // DecodeTag->threshold_half/4, // DecodeTag->previous_amplitude); // DEBUGGING if (DecodeTag->posCount == 1) { DecodeTag->sum1 = 0; DecodeTag->sum2 = 0; } if (DecodeTag->posCount <= 4) { DecodeTag->sum1 += amplitude; } else { DecodeTag->sum2 += amplitude; } if (DecodeTag->posCount == 8) { if (DecodeTag->sum1 > DecodeTag->threshold_half && DecodeTag->sum2 > DecodeTag->threshold_half) { // modulation in both halves if (DecodeTag->lastBit == LOGIC0) { // this was already part of EOF DecodeTag->state = STATE_TAG_EOF; } else { DecodeTag->posCount = 0; DecodeTag->previous_amplitude = amplitude; DecodeTag->state = STATE_TAG_SOF_LOW; LED_C_OFF(); } } else if (DecodeTag->sum1 < DecodeTag->threshold_half && DecodeTag->sum2 > DecodeTag->threshold_half) { // modulation in second half // logic 1 if (DecodeTag->lastBit == SOF_PART1) { // still part of SOF DecodeTag->lastBit = SOF_PART2; // SOF completed } else { DecodeTag->lastBit = LOGIC1; DecodeTag->shiftReg >>= 1; DecodeTag->shiftReg |= 0x80; DecodeTag->bitCount++; if (DecodeTag->bitCount == 8) { DecodeTag->output[DecodeTag->len] = DecodeTag->shiftReg; DecodeTag->len++; // if (DecodeTag->shiftReg == 0x12 && DecodeTag->len == 1) FpgaDisableTracing(); // DEBUGGING if (DecodeTag->len > DecodeTag->max_len) { // buffer overflow, give up LED_C_OFF(); return true; } DecodeTag->bitCount = 0; DecodeTag->shiftReg = 0; } } } else if (DecodeTag->sum1 > DecodeTag->threshold_half && DecodeTag->sum2 < DecodeTag->threshold_half) { // modulation in first half // logic 0 if (DecodeTag->lastBit == SOF_PART1) { // incomplete SOF DecodeTag->posCount = 0; DecodeTag->previous_amplitude = amplitude; DecodeTag->state = STATE_TAG_SOF_LOW; LED_C_OFF(); } else { DecodeTag->lastBit = LOGIC0; DecodeTag->shiftReg >>= 1; DecodeTag->bitCount++; if (DecodeTag->bitCount == 8) { DecodeTag->output[DecodeTag->len] = DecodeTag->shiftReg; DecodeTag->len++; // if (DecodeTag->shiftReg == 0x12 && DecodeTag->len == 1) FpgaDisableTracing(); // DEBUGGING if (DecodeTag->len > DecodeTag->max_len) { // buffer overflow, give up DecodeTag->posCount = 0; DecodeTag->previous_amplitude = amplitude; DecodeTag->state = STATE_TAG_SOF_LOW; LED_C_OFF(); } DecodeTag->bitCount = 0; DecodeTag->shiftReg = 0; } } } else { // no modulation if (DecodeTag->lastBit == SOF_PART2) { // only SOF (this is OK for iClass) LED_C_OFF(); return true; } else { DecodeTag->posCount = 0; DecodeTag->state = STATE_TAG_SOF_LOW; LED_C_OFF(); } } DecodeTag->posCount = 0; } DecodeTag->posCount++; break; case STATE_TAG_EOF: if (DecodeTag->posCount == 1) { DecodeTag->sum1 = 0; DecodeTag->sum2 = 0; } if (DecodeTag->posCount <= 4) { DecodeTag->sum1 += amplitude; } else { DecodeTag->sum2 += amplitude; } if (DecodeTag->posCount == 8) { if (DecodeTag->sum1 > DecodeTag->threshold_half && DecodeTag->sum2 < DecodeTag->threshold_half) { // modulation in first half DecodeTag->posCount = 0; DecodeTag->state = STATE_TAG_EOF_TAIL; } else { DecodeTag->posCount = 0; DecodeTag->previous_amplitude = amplitude; DecodeTag->state = STATE_TAG_SOF_LOW; LED_C_OFF(); } } DecodeTag->posCount++; break; case STATE_TAG_EOF_TAIL: if (DecodeTag->posCount == 1) { DecodeTag->sum1 = 0; DecodeTag->sum2 = 0; } if (DecodeTag->posCount <= 4) { DecodeTag->sum1 += amplitude; } else { DecodeTag->sum2 += amplitude; } if (DecodeTag->posCount == 8) { if (DecodeTag->sum1 < DecodeTag->threshold_half && DecodeTag->sum2 < DecodeTag->threshold_half) { // no modulation in both halves LED_C_OFF(); return true; } else { DecodeTag->posCount = 0; DecodeTag->previous_amplitude = amplitude; DecodeTag->state = STATE_TAG_SOF_LOW; LED_C_OFF(); } } DecodeTag->posCount++; break; } return false; } static void DecodeTagInit(DecodeTag_t *DecodeTag, uint8_t *data, uint16_t max_len) { DecodeTag->previous_amplitude = MAX_PREVIOUS_AMPLITUDE; DecodeTag->posCount = 0; DecodeTag->state = STATE_TAG_SOF_LOW; DecodeTag->output = data; DecodeTag->max_len = max_len; } static void DecodeTagReset(DecodeTag_t *DecodeTag) { DecodeTag->posCount = 0; DecodeTag->state = STATE_TAG_SOF_LOW; DecodeTag->previous_amplitude = MAX_PREVIOUS_AMPLITUDE; } /* * Receive and decode the tag response, also log to tracebuffer */ int GetIso15693AnswerFromTag(uint8_t* response, uint16_t max_len, uint16_t timeout, uint32_t *eof_time) { int samples = 0; int ret = 0; uint16_t dmaBuf[ISO15693_DMA_BUFFER_SIZE]; // the Decoder data structure DecodeTag_t DecodeTag = { 0 }; DecodeTagInit(&DecodeTag, response, max_len); // wait for last transfer to complete while (!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_TXEMPTY)); // And put the FPGA in the appropriate mode FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER | FPGA_HF_READER_SUBCARRIER_424_KHZ | FPGA_HF_READER_MODE_RECEIVE_AMPLITUDE); // Setup and start DMA. FpgaSetupSsc(FPGA_MAJOR_MODE_HF_READER); FpgaSetupSscDma((uint8_t*) dmaBuf, ISO15693_DMA_BUFFER_SIZE); uint32_t dma_start_time = 0; uint16_t *upTo = dmaBuf; for(;;) { uint16_t behindBy = ((uint16_t*)AT91C_BASE_PDC_SSC->PDC_RPR - upTo) & (ISO15693_DMA_BUFFER_SIZE-1); if (behindBy == 0) continue; samples++; if (samples == 1) { // DMA has transferred the very first data dma_start_time = GetCountSspClk() & 0xfffffff0; } uint16_t tagdata = *upTo++; if(upTo >= dmaBuf + ISO15693_DMA_BUFFER_SIZE) { // we have read all of the DMA buffer content. upTo = dmaBuf; // start reading the circular buffer from the beginning if (behindBy > (9*ISO15693_DMA_BUFFER_SIZE/10)) { Dbprintf("About to blow circular buffer - aborted! behindBy=%d", behindBy); ret = -1; break; } } if (AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_ENDRX)) { // DMA Counter Register had reached 0, already rotated. AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) dmaBuf; // refresh the DMA Next Buffer and AT91C_BASE_PDC_SSC->PDC_RNCR = ISO15693_DMA_BUFFER_SIZE; // DMA Next Counter registers } if (Handle15693SamplesFromTag(tagdata, &DecodeTag)) { *eof_time = dma_start_time + samples*16 - DELAY_TAG_TO_ARM; // end of EOF if (DecodeTag.lastBit == SOF_PART2) { *eof_time -= 8*16; // needed 8 additional samples to confirm single SOF (iCLASS) } if (DecodeTag.len > DecodeTag.max_len) { ret = -2; // buffer overflow } break; } if (samples > timeout && DecodeTag.state < STATE_TAG_RECEIVING_DATA) { ret = -1; // timeout break; } } FpgaDisableSscDma(); if (DEBUG) Dbprintf("samples = %d, ret = %d, Decoder: state = %d, lastBit = %d, len = %d, bitCount = %d, posCount = %d", samples, ret, DecodeTag.state, DecodeTag.lastBit, DecodeTag.len, DecodeTag.bitCount, DecodeTag.posCount); if (ret < 0) { return ret; } uint32_t sof_time = *eof_time - DecodeTag.len * 8 * 8 * 16 // time for byte transfers - 32 * 16 // time for SOF transfer - (DecodeTag.lastBit != SOF_PART2?32*16:0); // time for EOF transfer if (DEBUG) Dbprintf("timing: sof_time = %d, eof_time = %d", sof_time, *eof_time); LogTrace_ISO15693(DecodeTag.output, DecodeTag.len, sof_time*4, *eof_time*4, NULL, false); return DecodeTag.len; } //============================================================================= // An ISO15693 decoder for reader commands. // // This function is called 4 times per bit (every 2 subcarrier cycles). // Subcarrier frequency fs is 848kHz, 1/fs = 1,18us, i.e. function is called every 2,36us // LED handling: // LED B -> ON once we have received the SOF and are expecting the rest. // LED B -> OFF once we have received EOF or are in error state or unsynced // // Returns: true if we received a EOF // false if we are still waiting for some more //============================================================================= typedef struct DecodeReader { enum { STATE_READER_UNSYNCD, STATE_READER_AWAIT_1ST_FALLING_EDGE_OF_SOF, STATE_READER_AWAIT_1ST_RISING_EDGE_OF_SOF, STATE_READER_AWAIT_2ND_FALLING_EDGE_OF_SOF, STATE_READER_AWAIT_2ND_RISING_EDGE_OF_SOF, STATE_READER_AWAIT_END_OF_SOF_1_OUT_OF_4, STATE_READER_RECEIVE_DATA_1_OUT_OF_4, STATE_READER_RECEIVE_DATA_1_OUT_OF_256, STATE_READER_RECEIVE_JAMMING } state; enum { CODING_1_OUT_OF_4, CODING_1_OUT_OF_256 } Coding; uint8_t shiftReg; uint8_t bitCount; int byteCount; int byteCountMax; int posCount; int sum1, sum2; uint8_t *output; uint8_t jam_search_len; uint8_t *jam_search_string; } DecodeReader_t; static void DecodeReaderInit(DecodeReader_t* DecodeReader, uint8_t *data, uint16_t max_len, uint8_t jam_search_len, uint8_t *jam_search_string) { DecodeReader->output = data; DecodeReader->byteCountMax = max_len; DecodeReader->state = STATE_READER_UNSYNCD; DecodeReader->byteCount = 0; DecodeReader->bitCount = 0; DecodeReader->posCount = 1; DecodeReader->shiftReg = 0; DecodeReader->jam_search_len = jam_search_len; DecodeReader->jam_search_string = jam_search_string; } static void DecodeReaderReset(DecodeReader_t* DecodeReader) { DecodeReader->state = STATE_READER_UNSYNCD; } static int inline __attribute__((always_inline)) Handle15693SampleFromReader(bool bit, DecodeReader_t *DecodeReader) { switch (DecodeReader->state) { case STATE_READER_UNSYNCD: // wait for unmodulated carrier if (bit) { DecodeReader->state = STATE_READER_AWAIT_1ST_FALLING_EDGE_OF_SOF; } break; case STATE_READER_AWAIT_1ST_FALLING_EDGE_OF_SOF: if (!bit) { // we went low, so this could be the beginning of a SOF DecodeReader->posCount = 1; DecodeReader->state = STATE_READER_AWAIT_1ST_RISING_EDGE_OF_SOF; } break; case STATE_READER_AWAIT_1ST_RISING_EDGE_OF_SOF: DecodeReader->posCount++; if (bit) { // detected rising edge if (DecodeReader->posCount < 4) { // rising edge too early (nominally expected at 5) DecodeReader->state = STATE_READER_AWAIT_1ST_FALLING_EDGE_OF_SOF; } else { // SOF DecodeReader->state = STATE_READER_AWAIT_2ND_FALLING_EDGE_OF_SOF; } } else { if (DecodeReader->posCount > 5) { // stayed low for too long DecodeReaderReset(DecodeReader); } else { // do nothing, keep waiting } } break; case STATE_READER_AWAIT_2ND_FALLING_EDGE_OF_SOF: DecodeReader->posCount++; if (!bit) { // detected a falling edge if (DecodeReader->posCount < 20) { // falling edge too early (nominally expected at 21 earliest) DecodeReaderReset(DecodeReader); } else if (DecodeReader->posCount < 23) { // SOF for 1 out of 4 coding DecodeReader->Coding = CODING_1_OUT_OF_4; DecodeReader->state = STATE_READER_AWAIT_2ND_RISING_EDGE_OF_SOF; } else if (DecodeReader->posCount < 28) { // falling edge too early (nominally expected at 29 latest) DecodeReaderReset(DecodeReader); } else { // SOF for 1 out of 256 coding DecodeReader->Coding = CODING_1_OUT_OF_256; DecodeReader->state = STATE_READER_AWAIT_2ND_RISING_EDGE_OF_SOF; } } else { if (DecodeReader->posCount > 29) { // stayed high for too long DecodeReader->state = STATE_READER_AWAIT_1ST_FALLING_EDGE_OF_SOF; } else { // do nothing, keep waiting } } break; case STATE_READER_AWAIT_2ND_RISING_EDGE_OF_SOF: DecodeReader->posCount++; if (bit) { // detected rising edge if (DecodeReader->Coding == CODING_1_OUT_OF_256) { if (DecodeReader->posCount < 32) { // rising edge too early (nominally expected at 33) DecodeReader->state = STATE_READER_AWAIT_1ST_FALLING_EDGE_OF_SOF; } else { DecodeReader->posCount = 1; DecodeReader->bitCount = 0; DecodeReader->byteCount = 0; DecodeReader->sum1 = 1; DecodeReader->state = STATE_READER_RECEIVE_DATA_1_OUT_OF_256; LED_B_ON(); } } else { // CODING_1_OUT_OF_4 if (DecodeReader->posCount < 24) { // rising edge too early (nominally expected at 25) DecodeReader->state = STATE_READER_AWAIT_1ST_FALLING_EDGE_OF_SOF; } else { DecodeReader->posCount = 1; DecodeReader->state = STATE_READER_AWAIT_END_OF_SOF_1_OUT_OF_4; } } } else { if (DecodeReader->Coding == CODING_1_OUT_OF_256) { if (DecodeReader->posCount > 34) { // signal stayed low for too long DecodeReaderReset(DecodeReader); } else { // do nothing, keep waiting } } else { // CODING_1_OUT_OF_4 if (DecodeReader->posCount > 26) { // signal stayed low for too long DecodeReaderReset(DecodeReader); } else { // do nothing, keep waiting } } } break; case STATE_READER_AWAIT_END_OF_SOF_1_OUT_OF_4: DecodeReader->posCount++; if (bit) { if (DecodeReader->posCount == 9) { DecodeReader->posCount = 1; DecodeReader->bitCount = 0; DecodeReader->byteCount = 0; DecodeReader->sum1 = 1; DecodeReader->state = STATE_READER_RECEIVE_DATA_1_OUT_OF_4; LED_B_ON(); } else { // do nothing, keep waiting } } else { // unexpected falling edge DecodeReaderReset(DecodeReader); } break; case STATE_READER_RECEIVE_DATA_1_OUT_OF_4: DecodeReader->posCount++; if (DecodeReader->posCount == 1) { DecodeReader->sum1 = bit?1:0; } else if (DecodeReader->posCount <= 4) { if (bit) DecodeReader->sum1++; } else if (DecodeReader->posCount == 5) { DecodeReader->sum2 = bit?1:0; } else { if (bit) DecodeReader->sum2++; } if (DecodeReader->posCount == 8) { DecodeReader->posCount = 0; if (DecodeReader->sum1 <= 1 && DecodeReader->sum2 >= 3) { // EOF LED_B_OFF(); // Finished receiving DecodeReaderReset(DecodeReader); if (DecodeReader->byteCount != 0) { return true; } } else if (DecodeReader->sum1 >= 3 && DecodeReader->sum2 <= 1) { // detected a 2bit position DecodeReader->shiftReg >>= 2; DecodeReader->shiftReg |= (DecodeReader->bitCount << 6); } if (DecodeReader->bitCount == 15) { // we have a full byte DecodeReader->output[DecodeReader->byteCount++] = DecodeReader->shiftReg; if (DecodeReader->byteCount > DecodeReader->byteCountMax) { // buffer overflow, give up LED_B_OFF(); DecodeReaderReset(DecodeReader); } DecodeReader->bitCount = 0; DecodeReader->shiftReg = 0; if (DecodeReader->byteCount == DecodeReader->jam_search_len) { if (!memcmp(DecodeReader->output, DecodeReader->jam_search_string, DecodeReader->jam_search_len)) { LED_D_ON(); FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER | FPGA_HF_READER_MODE_SEND_JAM); DecodeReader->state = STATE_READER_RECEIVE_JAMMING; } } } else { DecodeReader->bitCount++; } } break; case STATE_READER_RECEIVE_DATA_1_OUT_OF_256: DecodeReader->posCount++; if (DecodeReader->posCount == 1) { DecodeReader->sum1 = bit?1:0; } else if (DecodeReader->posCount <= 4) { if (bit) DecodeReader->sum1++; } else if (DecodeReader->posCount == 5) { DecodeReader->sum2 = bit?1:0; } else if (bit) { DecodeReader->sum2++; } if (DecodeReader->posCount == 8) { DecodeReader->posCount = 0; if (DecodeReader->sum1 <= 1 && DecodeReader->sum2 >= 3) { // EOF LED_B_OFF(); // Finished receiving DecodeReaderReset(DecodeReader); if (DecodeReader->byteCount != 0) { return true; } } else if (DecodeReader->sum1 >= 3 && DecodeReader->sum2 <= 1) { // detected the bit position DecodeReader->shiftReg = DecodeReader->bitCount; } if (DecodeReader->bitCount == 255) { // we have a full byte DecodeReader->output[DecodeReader->byteCount++] = DecodeReader->shiftReg; if (DecodeReader->byteCount > DecodeReader->byteCountMax) { // buffer overflow, give up LED_B_OFF(); DecodeReaderReset(DecodeReader); } if (DecodeReader->byteCount == DecodeReader->jam_search_len) { if (!memcmp(DecodeReader->output, DecodeReader->jam_search_string, DecodeReader->jam_search_len)) { LED_D_ON(); FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER | FPGA_HF_READER_MODE_SEND_JAM); DecodeReader->state = STATE_READER_RECEIVE_JAMMING; } } } DecodeReader->bitCount++; } break; case STATE_READER_RECEIVE_JAMMING: DecodeReader->posCount++; if (DecodeReader->Coding == CODING_1_OUT_OF_4) { if (DecodeReader->posCount == 7*16) { // 7 bits jammed FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER | FPGA_HF_READER_MODE_SNOOP_AMPLITUDE); // stop jamming // FpgaDisableTracing(); LED_D_OFF(); } else if (DecodeReader->posCount == 8*16) { DecodeReader->posCount = 0; DecodeReader->output[DecodeReader->byteCount++] = 0x00; DecodeReader->state = STATE_READER_RECEIVE_DATA_1_OUT_OF_4; } } else { if (DecodeReader->posCount == 7*256) { // 7 bits jammend FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER | FPGA_HF_READER_MODE_SNOOP_AMPLITUDE); // stop jamming LED_D_OFF(); } else if (DecodeReader->posCount == 8*256) { DecodeReader->posCount = 0; DecodeReader->output[DecodeReader->byteCount++] = 0x00; DecodeReader->state = STATE_READER_RECEIVE_DATA_1_OUT_OF_256; } } break; default: LED_B_OFF(); DecodeReaderReset(DecodeReader); break; } return false; } //----------------------------------------------------------------------------- // Receive a command (from the reader to us, where we are the simulated tag), // and store it in the given buffer, up to the given maximum length. Keeps // spinning, waiting for a well-framed command, until either we get one // (returns len) or someone presses the pushbutton on the board (returns -1). // // Assume that we're called with the SSC (to the FPGA) and ADC path set // correctly. //----------------------------------------------------------------------------- int GetIso15693CommandFromReader(uint8_t *received, size_t max_len, uint32_t *eof_time) { int samples = 0; bool gotFrame = false; uint8_t b; uint8_t dmaBuf[ISO15693_DMA_BUFFER_SIZE]; // the decoder data structure DecodeReader_t DecodeReader = {0}; DecodeReaderInit(&DecodeReader, received, max_len, 0, NULL); // wait for last transfer to complete while (!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_TXEMPTY)); LED_D_OFF(); FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_SIMULATOR | FPGA_HF_SIMULATOR_NO_MODULATION); // clear receive register and wait for next transfer uint32_t temp = AT91C_BASE_SSC->SSC_RHR; (void) temp; while (!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY)) ; uint32_t dma_start_time = GetCountSspClk() & 0xfffffff8; // Setup and start DMA. FpgaSetupSscDma(dmaBuf, ISO15693_DMA_BUFFER_SIZE); uint8_t *upTo = dmaBuf; for (;;) { uint16_t behindBy = ((uint8_t*)AT91C_BASE_PDC_SSC->PDC_RPR - upTo) & (ISO15693_DMA_BUFFER_SIZE-1); if (behindBy == 0) continue; b = *upTo++; if (upTo >= dmaBuf + ISO15693_DMA_BUFFER_SIZE) { // we have read all of the DMA buffer content. upTo = dmaBuf; // start reading the circular buffer from the beginning if (behindBy > (9*ISO15693_DMA_BUFFER_SIZE/10)) { Dbprintf("About to blow circular buffer - aborted! behindBy=%d", behindBy); break; } } if (AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_ENDRX)) { // DMA Counter Register had reached 0, already rotated. AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) dmaBuf; // refresh the DMA Next Buffer and AT91C_BASE_PDC_SSC->PDC_RNCR = ISO15693_DMA_BUFFER_SIZE; // DMA Next Counter registers } for (int i = 7; i >= 0; i--) { if (Handle15693SampleFromReader((b >> i) & 0x01, &DecodeReader)) { *eof_time = dma_start_time + samples - DELAY_READER_TO_ARM; // end of EOF gotFrame = true; break; } samples++; } if (gotFrame) { break; } if (BUTTON_PRESS()) { DecodeReader.byteCount = -1; break; } WDT_HIT(); } FpgaDisableSscDma(); if (DEBUG) Dbprintf("samples = %d, gotFrame = %d, Decoder: state = %d, len = %d, bitCount = %d, posCount = %d", samples, gotFrame, DecodeReader.state, DecodeReader.byteCount, DecodeReader.bitCount, DecodeReader.posCount); if (DecodeReader.byteCount > 0) { uint32_t sof_time = *eof_time - DecodeReader.byteCount * (DecodeReader.Coding==CODING_1_OUT_OF_4?128:2048) // time for byte transfers - 32 // time for SOF transfer - 16; // time for EOF transfer LogTrace_ISO15693(DecodeReader.output, DecodeReader.byteCount, sof_time*32, *eof_time*32, NULL, true); } return DecodeReader.byteCount; } // Construct an identify (Inventory) request, which is the first // thing that you must send to a tag to get a response. static void BuildIdentifyRequest(uint8_t *cmd) { uint16_t crc; // one sub-carrier, inventory, 1 slot, fast rate cmd[0] = ISO15693_REQ_INVENTORY | ISO15693_REQINV_SLOT1 | ISO15693_REQ_DATARATE_HIGH; // inventory command code cmd[1] = 0x01; // no mask cmd[2] = 0x00; //Now the CRC crc = Iso15693Crc(cmd, 3); cmd[3] = crc & 0xff; cmd[4] = crc >> 8; } //----------------------------------------------------------------------------- // Start to read an ISO 15693 tag. We send an identify request, then wait // for the response. The response is not demodulated, just left in the buffer // so that it can be downloaded to a PC and processed there. //----------------------------------------------------------------------------- void AcquireRawAdcSamplesIso15693(void) { LED_A_ON(); uint8_t *dest = BigBuf_get_addr(); FpgaDownloadAndGo(FPGA_BITSTREAM_HF); FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER); LED_D_ON(); FpgaSetupSsc(FPGA_MAJOR_MODE_HF_READER); SetAdcMuxFor(GPIO_MUXSEL_HIPKD); uint8_t cmd[5]; BuildIdentifyRequest(cmd); CodeIso15693AsReader(cmd, sizeof(cmd)); // Give the tags time to energize SpinDelay(100); // Now send the command uint32_t start_time = 0; TransmitTo15693Tag(ToSend, ToSendMax, &start_time); // wait for last transfer to complete while (!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_TXEMPTY)) ; FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER | FPGA_HF_READER_SUBCARRIER_424_KHZ | FPGA_HF_READER_MODE_RECEIVE_AMPLITUDE); for(int c = 0; c < 4000; ) { if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) { uint16_t r = AT91C_BASE_SSC->SSC_RHR; dest[c++] = r >> 5; } } FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); LEDsoff(); } void SnoopIso15693(uint8_t jam_search_len, uint8_t *jam_search_string) { LED_A_ON(); FpgaDownloadAndGo(FPGA_BITSTREAM_HF); clear_trace(); set_tracing(true); // The DMA buffer, used to stream samples from the FPGA uint16_t dmaBuf[ISO15693_DMA_BUFFER_SIZE]; // Count of samples received so far, so that we can include timing // information in the trace buffer. int samples = 0; DecodeTag_t DecodeTag = {0}; uint8_t response[ISO15693_MAX_RESPONSE_LENGTH]; DecodeTagInit(&DecodeTag, response, sizeof(response)); DecodeReader_t DecodeReader = {0}; uint8_t cmd[ISO15693_MAX_COMMAND_LENGTH]; DecodeReaderInit(&DecodeReader, cmd, sizeof(cmd), jam_search_len, jam_search_string); // Print some debug information about the buffer sizes if (DEBUG) { Dbprintf("Snooping buffers initialized:"); Dbprintf(" Trace: %i bytes", BigBuf_max_traceLen()); Dbprintf(" Reader -> tag: %i bytes", ISO15693_MAX_COMMAND_LENGTH); Dbprintf(" tag -> Reader: %i bytes", ISO15693_MAX_RESPONSE_LENGTH); Dbprintf(" DMA: %i bytes", ISO15693_DMA_BUFFER_SIZE * sizeof(uint16_t)); } Dbprintf("Snoop started. Press PM3 Button to stop."); FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER | FPGA_HF_READER_MODE_SNOOP_AMPLITUDE); LED_D_OFF(); SetAdcMuxFor(GPIO_MUXSEL_HIPKD); FpgaSetupSsc(FPGA_MAJOR_MODE_HF_READER); StartCountSspClk(); FpgaSetupSscDma((uint8_t*) dmaBuf, ISO15693_DMA_BUFFER_SIZE); bool TagIsActive = false; bool ReaderIsActive = false; bool ExpectTagAnswer = false; uint32_t dma_start_time = 0; uint16_t *upTo = dmaBuf; uint16_t max_behindBy = 0; // And now we loop, receiving samples. for(;;) { uint16_t behindBy = ((uint16_t*)AT91C_BASE_PDC_SSC->PDC_RPR - upTo) & (ISO15693_DMA_BUFFER_SIZE-1); if (behindBy > max_behindBy) { max_behindBy = behindBy; } if (behindBy == 0) continue; samples++; if (samples == 1) { // DMA has transferred the very first data dma_start_time = GetCountSspClk() & 0xfffffff0; } uint16_t snoopdata = *upTo++; if (upTo >= dmaBuf + ISO15693_DMA_BUFFER_SIZE) { // we have read all of the DMA buffer content. upTo = dmaBuf; // start reading the circular buffer from the beginning if (behindBy > (9*ISO15693_DMA_BUFFER_SIZE/10)) { // FpgaDisableTracing(); Dbprintf("About to blow circular buffer - aborted! behindBy=%d, samples=%d", behindBy, samples); break; } if (AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_ENDRX)) { // DMA Counter Register had reached 0, already rotated. AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) dmaBuf; // refresh the DMA Next Buffer and AT91C_BASE_PDC_SSC->PDC_RNCR = ISO15693_DMA_BUFFER_SIZE; // DMA Next Counter registers WDT_HIT(); if (BUTTON_PRESS()) { DbpString("Snoop stopped."); break; } } } if (!TagIsActive) { // no need to try decoding reader data if the tag is sending if (Handle15693SampleFromReader(snoopdata & 0x02, &DecodeReader)) { // FpgaDisableSscDma(); uint32_t eof_time = dma_start_time + samples*16 + 8 - DELAY_READER_TO_ARM_SNOOP; // end of EOF if (DecodeReader.byteCount > 0) { uint32_t sof_time = eof_time - DecodeReader.byteCount * (DecodeReader.Coding==CODING_1_OUT_OF_4?128*16:2048*16) // time for byte transfers - 32*16 // time for SOF transfer - 16*16; // time for EOF transfer LogTrace_ISO15693(DecodeReader.output, DecodeReader.byteCount, sof_time*4, eof_time*4, NULL, true); } /* And ready to receive another command. */ DecodeReaderReset(&DecodeReader); /* And also reset the demod code, which might have been */ /* false-triggered by the commands from the reader. */ DecodeTagReset(&DecodeTag); ReaderIsActive = false; ExpectTagAnswer = true; // upTo = dmaBuf; // samples = 0; // FpgaSetupSscDma((uint8_t*) dmaBuf, ISO15693_DMA_BUFFER_SIZE); // continue; } else if (Handle15693SampleFromReader(snoopdata & 0x01, &DecodeReader)) { // FpgaDisableSscDma(); uint32_t eof_time = dma_start_time + samples*16 + 16 - DELAY_READER_TO_ARM_SNOOP; // end of EOF if (DecodeReader.byteCount > 0) { uint32_t sof_time = eof_time - DecodeReader.byteCount * (DecodeReader.Coding==CODING_1_OUT_OF_4?128*16:2048*16) // time for byte transfers - 32*16 // time for SOF transfer - 16*16; // time for EOF transfer LogTrace_ISO15693(DecodeReader.output, DecodeReader.byteCount, sof_time*4, eof_time*4, NULL, true); } /* And ready to receive another command. */ DecodeReaderReset(&DecodeReader); /* And also reset the demod code, which might have been */ /* false-triggered by the commands from the reader. */ DecodeTagReset(&DecodeTag); ReaderIsActive = false; ExpectTagAnswer = true; // upTo = dmaBuf; // samples = 0; // FpgaSetupSscDma((uint8_t*) dmaBuf, ISO15693_DMA_BUFFER_SIZE); // continue; } else { ReaderIsActive = (DecodeReader.state >= STATE_READER_RECEIVE_DATA_1_OUT_OF_4); } } if (!ReaderIsActive && ExpectTagAnswer) { // no need to try decoding tag data if the reader is currently sending or no answer expected yet if (Handle15693SamplesFromTag(snoopdata >> 2, &DecodeTag)) { // FpgaDisableSscDma(); uint32_t eof_time = dma_start_time + samples*16 - DELAY_TAG_TO_ARM_SNOOP; // end of EOF if (DecodeTag.lastBit == SOF_PART2) { eof_time -= 8*16; // needed 8 additional samples to confirm single SOF (iCLASS) } uint32_t sof_time = eof_time - DecodeTag.len * 8 * 8 * 16 // time for byte transfers - 32 * 16 // time for SOF transfer - (DecodeTag.lastBit != SOF_PART2?32*16:0); // time for EOF transfer LogTrace_ISO15693(DecodeTag.output, DecodeTag.len, sof_time*4, eof_time*4, NULL, false); // And ready to receive another response. DecodeTagReset(&DecodeTag); DecodeReaderReset(&DecodeReader); ExpectTagAnswer = false; TagIsActive = false; // upTo = dmaBuf; // samples = 0; // FpgaSetupSscDma((uint8_t*) dmaBuf, ISO15693_DMA_BUFFER_SIZE); // continue; } else { TagIsActive = (DecodeTag.state >= STATE_TAG_RECEIVING_DATA); } } } FpgaDisableSscDma(); DbpString("Snoop statistics:"); Dbprintf(" ExpectTagAnswer: %d, TagIsActive: %d, ReaderIsActive: %d", ExpectTagAnswer, TagIsActive, ReaderIsActive); Dbprintf(" DecodeTag State: %d", DecodeTag.state); Dbprintf(" DecodeTag byteCnt: %d", DecodeTag.len); Dbprintf(" DecodeTag posCount: %d", DecodeTag.posCount); Dbprintf(" DecodeReader State: %d", DecodeReader.state); Dbprintf(" DecodeReader byteCnt: %d", DecodeReader.byteCount); Dbprintf(" DecodeReader posCount: %d", DecodeReader.posCount); Dbprintf(" Trace length: %d", BigBuf_get_traceLen()); Dbprintf(" Max behindBy: %d", max_behindBy); } // Initialize the proxmark as iso15k reader void Iso15693InitReader(void) { FpgaDownloadAndGo(FPGA_BITSTREAM_HF); // switch field off and wait until tag resets FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); LED_D_OFF(); SpinDelay(10); // switch field on FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER); LED_D_ON(); // initialize SSC and select proper AD input FpgaSetupSsc(FPGA_MAJOR_MODE_HF_READER); SetAdcMuxFor(GPIO_MUXSEL_HIPKD); // give tags some time to energize SpinDelay(250); } /////////////////////////////////////////////////////////////////////// // ISO 15693 Part 3 - Air Interface // This section basically contains transmission and receiving of bits /////////////////////////////////////////////////////////////////////// // uid is in transmission order (which is reverse of display order) static void BuildReadBlockRequest(uint8_t *uid, uint8_t blockNumber, uint8_t *cmd) { uint16_t crc; // If we set the Option_Flag in this request, the VICC will respond with the security status of the block // followed by the block data cmd[0] = ISO15693_REQ_OPTION | ISO15693_REQ_ADDRESS | ISO15693_REQ_DATARATE_HIGH; // READ BLOCK command code cmd[1] = ISO15693_READBLOCK; // UID may be optionally specified here // 64-bit UID cmd[2] = uid[0]; cmd[3] = uid[1]; cmd[4] = uid[2]; cmd[5] = uid[3]; cmd[6] = uid[4]; cmd[7] = uid[5]; cmd[8] = uid[6]; cmd[9] = uid[7]; // 0xe0; // always e0 (not exactly unique) // Block number to read cmd[10] = blockNumber; //Now the CRC crc = Iso15693Crc(cmd, 11); // the crc needs to be calculated over 11 bytes cmd[11] = crc & 0xff; cmd[12] = crc >> 8; } // Now the VICC>VCD responses when we are simulating a tag static void BuildInventoryResponse(uint8_t *uid) { uint8_t cmd[12]; uint16_t crc; cmd[0] = 0; // No error, no protocol format extension cmd[1] = 0; // DSFID (data storage format identifier). 0x00 = not supported // 64-bit UID cmd[2] = uid[7]; //0x32; cmd[3] = uid[6]; //0x4b; cmd[4] = uid[5]; //0x03; cmd[5] = uid[4]; //0x01; cmd[6] = uid[3]; //0x00; cmd[7] = uid[2]; //0x10; cmd[8] = uid[1]; //0x05; cmd[9] = uid[0]; //0xe0; //Now the CRC crc = Iso15693Crc(cmd, 10); cmd[10] = crc & 0xff; cmd[11] = crc >> 8; CodeIso15693AsTag(cmd, sizeof(cmd)); } // Universal Method for sending to and recv bytes from a tag // init ... should we initialize the reader? // speed ... 0 low speed, 1 hi speed // *recv will contain the tag's answer // return: length of received data, or -1 for timeout int SendDataTag(uint8_t *send, int sendlen, bool init, bool speed_fast, uint8_t *recv, uint16_t max_recv_len, uint32_t start_time, uint16_t timeout, uint32_t *eof_time) { if (init) { Iso15693InitReader(); StartCountSspClk(); } int answerLen = 0; if (speed_fast) { // high speed (1 out of 4) CodeIso15693AsReader(send, sendlen); } else { // low speed (1 out of 256) CodeIso15693AsReader256(send, sendlen); } TransmitTo15693Tag(ToSend, ToSendMax, &start_time); uint32_t end_time = start_time + 32*(8*ToSendMax-4); // substract the 4 padding bits after EOF LogTrace_ISO15693(send, sendlen, start_time*4, end_time*4, NULL, true); // Now wait for a response if (recv != NULL) { answerLen = GetIso15693AnswerFromTag(recv, max_recv_len, timeout, eof_time); } return answerLen; } int SendDataTagEOF(uint8_t *recv, uint16_t max_recv_len, uint32_t start_time, uint16_t timeout, uint32_t *eof_time) { int answerLen = 0; CodeIso15693AsReaderEOF(); TransmitTo15693Tag(ToSend, ToSendMax, &start_time); uint32_t end_time = start_time + 32*(8*ToSendMax-4); // substract the 4 padding bits after EOF LogTrace_ISO15693(NULL, 0, start_time*4, end_time*4, NULL, true); // Now wait for a response if (recv != NULL) { answerLen = GetIso15693AnswerFromTag(recv, max_recv_len, timeout, eof_time); } return answerLen; } // -------------------------------------------------------------------- // Debug Functions // -------------------------------------------------------------------- // Decodes a message from a tag and displays its metadata and content #define DBD15STATLEN 48 void DbdecodeIso15693Answer(int len, uint8_t *d) { char status[DBD15STATLEN+1]={0}; uint16_t crc; if (len > 3) { if (d[0] & ISO15693_RES_EXT) strncat(status,"ProtExt ", DBD15STATLEN); if (d[0] & ISO15693_RES_ERROR) { // error strncat(status,"Error ", DBD15STATLEN); switch (d[1]) { case 0x01: strncat(status,"01:notSupp", DBD15STATLEN); break; case 0x02: strncat(status,"02:notRecog", DBD15STATLEN); break; case 0x03: strncat(status,"03:optNotSupp", DBD15STATLEN); break; case 0x0f: strncat(status,"0f:noInfo", DBD15STATLEN); break; case 0x10: strncat(status,"10:doesn'tExist", DBD15STATLEN); break; case 0x11: strncat(status,"11:lockAgain", DBD15STATLEN); break; case 0x12: strncat(status,"12:locked", DBD15STATLEN); break; case 0x13: strncat(status,"13:progErr", DBD15STATLEN); break; case 0x14: strncat(status,"14:lockErr", DBD15STATLEN); break; default: strncat(status,"unknownErr", DBD15STATLEN); } strncat(status," ", DBD15STATLEN); } else { strncat(status,"NoErr ", DBD15STATLEN); } crc=Iso15693Crc(d,len-2); if ( (( crc & 0xff ) == d[len-2]) && (( crc >> 8 ) == d[len-1]) ) strncat(status,"CrcOK",DBD15STATLEN); else strncat(status,"CrcFail!",DBD15STATLEN); Dbprintf("%s",status); } } /////////////////////////////////////////////////////////////////////// // Functions called via USB/Client /////////////////////////////////////////////////////////////////////// void SetDebugIso15693(uint32_t debug) { DEBUG=debug; Dbprintf("Iso15693 Debug is now %s",DEBUG?"on":"off"); return; } //--------------------------------------------------------------------------------------- // Simulate an ISO15693 reader, perform anti-collision and then attempt to read a sector. // all demodulation performed in arm rather than host. - greg //--------------------------------------------------------------------------------------- void ReaderIso15693(uint32_t parameter) { LED_A_ON(); set_tracing(true); uint8_t TagUID[8] = {0x00}; uint8_t answer[ISO15693_MAX_RESPONSE_LENGTH]; // FIRST WE RUN AN INVENTORY TO GET THE TAG UID // THIS MEANS WE CAN PRE-BUILD REQUESTS TO SAVE CPU TIME // Now send the IDENTIFY command uint8_t cmd[5]; BuildIdentifyRequest(cmd); uint32_t start_time = 0; uint32_t eof_time; int answerLen = SendDataTag(cmd, sizeof(cmd), true, true, answer, sizeof(answer), start_time, ISO15693_READER_TIMEOUT, &eof_time); start_time = eof_time + DELAY_ISO15693_VICC_TO_VCD_READER; if (answerLen >= 12) { // we should do a better check than this TagUID[0] = answer[2]; TagUID[1] = answer[3]; TagUID[2] = answer[4]; TagUID[3] = answer[5]; TagUID[4] = answer[6]; TagUID[5] = answer[7]; TagUID[6] = answer[8]; // IC Manufacturer code TagUID[7] = answer[9]; // always E0 } Dbprintf("%d octets read from IDENTIFY request:", answerLen); DbdecodeIso15693Answer(answerLen, answer); Dbhexdump(answerLen, answer, false); // UID is reverse if (answerLen >= 12) Dbprintf("UID = %02hX%02hX%02hX%02hX%02hX%02hX%02hX%02hX", TagUID[7],TagUID[6],TagUID[5],TagUID[4], TagUID[3],TagUID[2],TagUID[1],TagUID[0]); // read all pages if (answerLen >= 12 && DEBUG) { for (int i = 0; i < 32; i++) { // sanity check, assume max 32 pages uint8_t cmd[13]; BuildReadBlockRequest(TagUID, i, cmd); answerLen = SendDataTag(cmd, sizeof(cmd), false, true, answer, sizeof(answer), start_time, ISO15693_READER_TIMEOUT, &eof_time); start_time = eof_time + DELAY_ISO15693_VICC_TO_VCD_READER; if (answerLen > 0) { Dbprintf("READ SINGLE BLOCK %d returned %d octets:", i, answerLen); DbdecodeIso15693Answer(answerLen, answer); Dbhexdump(answerLen, answer, false); if ( *((uint32_t*) answer) == 0x07160101 ) break; // exit on NoPageErr } } } // for the time being, switch field off to protect RDV4 // note: this prevents using hf 15 cmd with s option - which isn't implemented yet anyway FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); LED_D_OFF(); LED_A_OFF(); } // Initialize the proxmark as iso15k tag void Iso15693InitTag(void) { FpgaDownloadAndGo(FPGA_BITSTREAM_HF); SetAdcMuxFor(GPIO_MUXSEL_HIPKD); FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_SIMULATOR | FPGA_HF_SIMULATOR_NO_MODULATION); LED_D_OFF(); FpgaSetupSsc(FPGA_MAJOR_MODE_HF_SIMULATOR); StartCountSspClk(); } // Simulate an ISO15693 TAG. // For Inventory command: print command and send Inventory Response with given UID // TODO: interpret other reader commands and send appropriate response void SimTagIso15693(uint32_t parameter, uint8_t *uid) { LED_A_ON(); Iso15693InitTag(); // Build a suitable response to the reader INVENTORY command BuildInventoryResponse(uid); // Listen to reader while (!BUTTON_PRESS()) { uint8_t cmd[ISO15693_MAX_COMMAND_LENGTH]; uint32_t eof_time = 0, start_time = 0; int cmd_len = GetIso15693CommandFromReader(cmd, sizeof(cmd), &eof_time); if ((cmd_len >= 5) && (cmd[0] & ISO15693_REQ_INVENTORY) && (cmd[1] == ISO15693_INVENTORY)) { // TODO: check more flags bool slow = !(cmd[0] & ISO15693_REQ_DATARATE_HIGH); start_time = eof_time + DELAY_ISO15693_VCD_TO_VICC_SIM; TransmitTo15693Reader(ToSend, ToSendMax, &start_time, 0, slow); } Dbprintf("%d bytes read from reader:", cmd_len); Dbhexdump(cmd_len, cmd, false); } FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); LED_D_OFF(); LED_A_OFF(); } // Since there is no standardized way of reading the AFI out of a tag, we will brute force it // (some manufactures offer a way to read the AFI, though) void BruteforceIso15693Afi(uint32_t speed) { LED_A_ON(); uint8_t data[6]; uint8_t recv[ISO15693_MAX_RESPONSE_LENGTH]; int datalen = 0, recvlen = 0; uint32_t eof_time; // first without AFI // Tags should respond without AFI and with AFI=0 even when AFI is active data[0] = ISO15693_REQ_DATARATE_HIGH | ISO15693_REQ_INVENTORY | ISO15693_REQINV_SLOT1; data[1] = ISO15693_INVENTORY; data[2] = 0; // mask length datalen = Iso15693AddCrc(data,3); uint32_t start_time = GetCountSspClk(); recvlen = SendDataTag(data, datalen, true, speed, recv, sizeof(recv), 0, ISO15693_READER_TIMEOUT, &eof_time); start_time = eof_time + DELAY_ISO15693_VICC_TO_VCD_READER; WDT_HIT(); if (recvlen>=12) { Dbprintf("NoAFI UID=%s", Iso15693sprintUID(NULL, &recv[2])); } // now with AFI data[0] = ISO15693_REQ_DATARATE_HIGH | ISO15693_REQ_INVENTORY | ISO15693_REQINV_AFI | ISO15693_REQINV_SLOT1; data[1] = ISO15693_INVENTORY; data[2] = 0; // AFI data[3] = 0; // mask length for (int i = 0; i < 256; i++) { data[2] = i & 0xFF; datalen = Iso15693AddCrc(data,4); recvlen = SendDataTag(data, datalen, false, speed, recv, sizeof(recv), start_time, ISO15693_READER_TIMEOUT, &eof_time); start_time = eof_time + DELAY_ISO15693_VICC_TO_VCD_READER; WDT_HIT(); if (recvlen >= 12) { Dbprintf("AFI=%i UID=%s", i, Iso15693sprintUID(NULL, &recv[2])); } } Dbprintf("AFI Bruteforcing done."); FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); LED_D_OFF(); LED_A_OFF(); } // Allows to directly send commands to the tag via the client void DirectTag15693Command(uint32_t datalen, uint32_t speed, uint32_t recv, uint8_t data[]) { LED_A_ON(); int recvlen = 0; uint8_t recvbuf[ISO15693_MAX_RESPONSE_LENGTH]; uint32_t eof_time; uint16_t timeout; bool request_answer = false; switch (data[1]) { case ISO15693_WRITEBLOCK: case ISO15693_LOCKBLOCK: case ISO15693_WRITE_MULTI_BLOCK: case ISO15693_WRITE_AFI: case ISO15693_LOCK_AFI: case ISO15693_WRITE_DSFID: case ISO15693_LOCK_DSFID: timeout = ISO15693_READER_TIMEOUT_WRITE; request_answer = data[0] & ISO15693_REQ_OPTION; break; default: timeout = ISO15693_READER_TIMEOUT; } if (DEBUG) { Dbprintf("SEND:"); Dbhexdump(datalen, data, false); } recvlen = SendDataTag(data, datalen, true, speed, (recv?recvbuf:NULL), sizeof(recvbuf), 0, timeout, &eof_time); if (request_answer) { // send a single EOF to get the tag response recvlen = SendDataTagEOF((recv?recvbuf:NULL), sizeof(recvbuf), 0, ISO15693_READER_TIMEOUT, &eof_time); } // for the time being, switch field off to protect rdv4.0 // note: this prevents using hf 15 cmd with s option - which isn't implemented yet anyway FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); LED_D_OFF(); if (recv) { if (DEBUG) { Dbprintf("RECV:"); if (recvlen > 0) { Dbhexdump(recvlen, recvbuf, false); DbdecodeIso15693Answer(recvlen, recvbuf); } } if (recvlen > ISO15693_MAX_RESPONSE_LENGTH) { recvlen = ISO15693_MAX_RESPONSE_LENGTH; } cmd_send(CMD_ACK, recvlen, 0, 0, recvbuf, ISO15693_MAX_RESPONSE_LENGTH); } LED_A_OFF(); } //----------------------------------------------------------------------------- // Work with "magic Chinese" card. // //----------------------------------------------------------------------------- // Set the UID on Magic ISO15693 tag (based on Iceman's LUA-script). void SetTag15693Uid(uint8_t *uid) { LED_A_ON(); uint8_t cmd[4][9] = { {ISO15693_REQ_DATARATE_HIGH, ISO15693_WRITEBLOCK, 0x3e, 0x00, 0x00, 0x00, 0x00}, {ISO15693_REQ_DATARATE_HIGH, ISO15693_WRITEBLOCK, 0x3f, 0x69, 0x96, 0x00, 0x00}, {ISO15693_REQ_DATARATE_HIGH, ISO15693_WRITEBLOCK, 0x38}, {ISO15693_REQ_DATARATE_HIGH, ISO15693_WRITEBLOCK, 0x39} }; uint16_t crc; int recvlen = 0; uint8_t recvbuf[ISO15693_MAX_RESPONSE_LENGTH]; uint32_t eof_time; // Command 3 : 022138u8u7u6u5 (where uX = uid byte X) cmd[2][3] = uid[7]; cmd[2][4] = uid[6]; cmd[2][5] = uid[5]; cmd[2][6] = uid[4]; // Command 4 : 022139u4u3u2u1 (where uX = uid byte X) cmd[3][3] = uid[3]; cmd[3][4] = uid[2]; cmd[3][5] = uid[1]; cmd[3][6] = uid[0]; uint32_t start_time = 0; for (int i = 0; i < 4; i++) { // Add the CRC crc = Iso15693Crc(cmd[i], 7); cmd[i][7] = crc & 0xff; cmd[i][8] = crc >> 8; recvlen = SendDataTag(cmd[i], sizeof(cmd[i]), i==0?true:false, true, recvbuf, sizeof(recvbuf), start_time, ISO15693_READER_TIMEOUT_WRITE, &eof_time); start_time = eof_time + DELAY_ISO15693_VICC_TO_VCD_READER; if (DEBUG) { Dbprintf("SEND:"); Dbhexdump(sizeof(cmd[i]), cmd[i], false); Dbprintf("RECV:"); if (recvlen > 0) { Dbhexdump(recvlen, recvbuf, false); DbdecodeIso15693Answer(recvlen, recvbuf); } } // Note: need to know if we expect an answer from one of the magic commands // if (recvlen < 0) { // break; // } } FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); LED_D_OFF(); cmd_send(CMD_ACK, recvlen, 0, 0, recvbuf, recvlen); LED_A_OFF(); } // -------------------------------------------------------------------- // -- Misc & deprecated functions // -------------------------------------------------------------------- /* // do not use; has a fix UID static void __attribute__((unused)) BuildSysInfoRequest(uint8_t *uid) { uint8_t cmd[12]; uint16_t crc; // If we set the Option_Flag in this request, the VICC will respond with the security status of the block // followed by the block data // one sub-carrier, inventory, 1 slot, fast rate cmd[0] = (1 << 5) | (1 << 1); // no SELECT bit // System Information command code cmd[1] = 0x2B; // UID may be optionally specified here // 64-bit UID cmd[2] = 0x32; cmd[3]= 0x4b; cmd[4] = 0x03; cmd[5] = 0x01; cmd[6] = 0x00; cmd[7] = 0x10; cmd[8] = 0x05; cmd[9]= 0xe0; // always e0 (not exactly unique) //Now the CRC crc = Iso15693Crc(cmd, 10); // the crc needs to be calculated over 2 bytes cmd[10] = crc & 0xff; cmd[11] = crc >> 8; CodeIso15693AsReader(cmd, sizeof(cmd)); } // do not use; has a fix UID static void __attribute__((unused)) BuildReadMultiBlockRequest(uint8_t *uid) { uint8_t cmd[14]; uint16_t crc; // If we set the Option_Flag in this request, the VICC will respond with the security status of the block // followed by the block data // one sub-carrier, inventory, 1 slot, fast rate cmd[0] = (1 << 5) | (1 << 1); // no SELECT bit // READ Multi BLOCK command code cmd[1] = 0x23; // UID may be optionally specified here // 64-bit UID cmd[2] = 0x32; cmd[3]= 0x4b; cmd[4] = 0x03; cmd[5] = 0x01; cmd[6] = 0x00; cmd[7] = 0x10; cmd[8] = 0x05; cmd[9]= 0xe0; // always e0 (not exactly unique) // First Block number to read cmd[10] = 0x00; // Number of Blocks to read cmd[11] = 0x2f; // read quite a few //Now the CRC crc = Iso15693Crc(cmd, 12); // the crc needs to be calculated over 2 bytes cmd[12] = crc & 0xff; cmd[13] = crc >> 8; CodeIso15693AsReader(cmd, sizeof(cmd)); } // do not use; has a fix UID static void __attribute__((unused)) BuildArbitraryRequest(uint8_t *uid,uint8_t CmdCode) { uint8_t cmd[14]; uint16_t crc; // If we set the Option_Flag in this request, the VICC will respond with the security status of the block // followed by the block data // one sub-carrier, inventory, 1 slot, fast rate cmd[0] = (1 << 5) | (1 << 1); // no SELECT bit // READ BLOCK command code cmd[1] = CmdCode; // UID may be optionally specified here // 64-bit UID cmd[2] = 0x32; cmd[3]= 0x4b; cmd[4] = 0x03; cmd[5] = 0x01; cmd[6] = 0x00; cmd[7] = 0x10; cmd[8] = 0x05; cmd[9]= 0xe0; // always e0 (not exactly unique) // Parameter cmd[10] = 0x00; cmd[11] = 0x0a; // cmd[12] = 0x00; // cmd[13] = 0x00; //Now the CRC crc = Iso15693Crc(cmd, 12); // the crc needs to be calculated over 2 bytes cmd[12] = crc & 0xff; cmd[13] = crc >> 8; CodeIso15693AsReader(cmd, sizeof(cmd)); } // do not use; has a fix UID static void __attribute__((unused)) BuildArbitraryCustomRequest(uint8_t uid[], uint8_t CmdCode) { uint8_t cmd[14]; uint16_t crc; // If we set the Option_Flag in this request, the VICC will respond with the security status of the block // followed by the block data // one sub-carrier, inventory, 1 slot, fast rate cmd[0] = (1 << 5) | (1 << 1); // no SELECT bit // READ BLOCK command code cmd[1] = CmdCode; // UID may be optionally specified here // 64-bit UID cmd[2] = 0x32; cmd[3]= 0x4b; cmd[4] = 0x03; cmd[5] = 0x01; cmd[6] = 0x00; cmd[7] = 0x10; cmd[8] = 0x05; cmd[9]= 0xe0; // always e0 (not exactly unique) // Parameter cmd[10] = 0x05; // for custom codes this must be manufacturer code cmd[11] = 0x00; // cmd[12] = 0x00; // cmd[13] = 0x00; //Now the CRC crc = Iso15693Crc(cmd, 12); // the crc needs to be calculated over 2 bytes cmd[12] = crc & 0xff; cmd[13] = crc >> 8; CodeIso15693AsReader(cmd, sizeof(cmd)); } */