X-Git-Url: https://git.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/blobdiff_plain/28afbd2bee49027d042030bfce07db2db8c7508b..77cd612f15cb8b50229dbba5e8ec18c8a0bca6f5:/armsrc/iso14443a.c?ds=sidebyside diff --git a/armsrc/iso14443a.c b/armsrc/iso14443a.c index ca7c3ba4..63cc32ae 100644 --- a/armsrc/iso14443a.c +++ b/armsrc/iso14443a.c @@ -88,25 +88,25 @@ void iso14a_set_timeout(uint32_t timeout) { //----------------------------------------------------------------------------- byte_t oddparity (const byte_t bt) { - return OddByteParity[bt]; + return OddByteParity[bt]; } uint32_t GetParity(const uint8_t * pbtCmd, int iLen) { - int i; - uint32_t dwPar = 0; + int i; + uint32_t dwPar = 0; - // Generate the encrypted data - for (i = 0; i < iLen; i++) { - // Save the encrypted parity bit - dwPar |= ((OddByteParity[pbtCmd[i]]) << i); - } - return dwPar; + // Generate the encrypted data + for (i = 0; i < iLen; i++) { + // Save the encrypted parity bit + dwPar |= ((OddByteParity[pbtCmd[i]]) << i); + } + return dwPar; } void AppendCrc14443a(uint8_t* data, int len) { - ComputeCrc14443(CRC_14443_A,data,len,data+len,data+len+1); + ComputeCrc14443(CRC_14443_A,data,len,data+len,data+len+1); } // The function LogTrace() is also used by the iClass implementation in iClass.c @@ -584,7 +584,7 @@ void RAMFUNC SnoopIso14443a(uint8_t param) { LEDsoff(); // init trace buffer - iso14a_clear_trace(); + iso14a_clear_trace(); // 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 @@ -775,54 +775,54 @@ static void CodeIso14443aAsTag(const uint8_t *cmd, int len){ CodeIso14443aAsTagPar(cmd, len, GetParity(cmd, len)); } -//----------------------------------------------------------------------------- -// This is to send a NACK kind of answer, its only 3 bits, I know it should be 4 -//----------------------------------------------------------------------------- -static void CodeStrangeAnswerAsTag() -{ - 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; - - // 0 - ToSend[++ToSendMax] = SEC_E; - - // 0 - ToSend[++ToSendMax] = SEC_E; - - // 1 - ToSend[++ToSendMax] = SEC_D; - - // Send stopbit - ToSend[++ToSendMax] = SEC_F; - - // Flush the buffer in FPGA!! - for(i = 0; i < 5; i++) { - ToSend[++ToSendMax] = SEC_F; - } - - // Convert from last byte pos to length - ToSendMax++; -} +////----------------------------------------------------------------------------- +//// This is to send a NACK kind of answer, its only 3 bits, I know it should be 4 +////----------------------------------------------------------------------------- +//static void CodeStrangeAnswerAsTag() +//{ +// 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; +// +// // 0 +// ToSend[++ToSendMax] = SEC_E; +// +// // 0 +// ToSend[++ToSendMax] = SEC_E; +// +// // 1 +// ToSend[++ToSendMax] = SEC_D; +// +// // Send stopbit +// ToSend[++ToSendMax] = SEC_F; +// +// // Flush the buffer in FPGA!! +// for(i = 0; i < 5; i++) { +// ToSend[++ToSendMax] = SEC_F; +// } +// +// // Convert from last byte pos to length +// ToSendMax++; +//} static void Code4bitAnswerAsTag(uint8_t cmd) { int i; - ToSendReset(); + ToSendReset(); // Correction bit, might be removed when not needed ToSendStuffBit(0); @@ -855,8 +855,8 @@ static void Code4bitAnswerAsTag(uint8_t cmd) ToSend[++ToSendMax] = SEC_F; } - // Convert from last byte pos to length - ToSendMax++; + // Convert from last byte pos to length + ToSendMax++; } //----------------------------------------------------------------------------- @@ -908,15 +908,76 @@ int EmSendCmdEx(uint8_t *resp, int respLen, int correctionNeeded); int EmSendCmd(uint8_t *resp, int respLen); int EmSendCmdPar(uint8_t *resp, int respLen, uint32_t par); +static uint8_t* free_buffer_pointer = (((uint8_t *)BigBuf) + FREE_BUFFER_OFFSET); + +typedef struct { + uint8_t* response; + size_t response_n; + uint8_t* modulation; + size_t modulation_n; +} tag_response_info_t; + +void reset_free_buffer() { + free_buffer_pointer = (((uint8_t *)BigBuf) + FREE_BUFFER_OFFSET); +} + +bool prepare_tag_modulation(tag_response_info_t* response_info, size_t max_buffer_size) { + // Exmaple 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 + response_info->modulation_n = ToSendMax; + + 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 = (((uint8_t *)BigBuf)+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 + // Enable and clear the trace tracing = TRUE; - iso14a_clear_trace(); + iso14a_clear_trace(); // This function contains the tag emulation uint8_t sak; @@ -990,57 +1051,41 @@ void SimulateIso14443aTag(int tagType, int uid_1st, int uid_2nd, byte_t* data) ComputeCrc14443(CRC_14443_A, response3a, 1, &response3a[1], &response3a[2]); uint8_t response5[] = { 0x00, 0x00, 0x00, 0x00 }; // Very random tag nonce - uint8_t response6[] = { 0x03, 0x3B, 0x00, 0x00, 0x00 }; // dummy ATS (pseudo-ATR), answer to RATS - ComputeCrc14443(CRC_14443_A, response6, 3, &response6[3], &response6[4]); - - uint8_t *resp; - int respLen; - - // Longest possible response will be 16 bytes + 2 CRC = 18 bytes - // This will need - // 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 - // - // 166 bytes, since every bit that needs to be send costs us a byte - // - - // Respond with card type - uint8_t *resp1 = (((uint8_t *)BigBuf) + FREE_BUFFER_OFFSET); - int resp1Len; - - // Anticollision cascade1 - respond with uid - uint8_t *resp2 = (((uint8_t *)BigBuf) + FREE_BUFFER_OFFSET + 166); - int resp2Len; - - // Anticollision cascade2 - respond with 2nd half of uid if asked - // we're only going to be asked if we set the 1st byte of the UID (during cascade1) to 0x88 - uint8_t *resp2a = (((uint8_t *)BigBuf) + 1140); - int resp2aLen; - - // Acknowledge select - cascade 1 - uint8_t *resp3 = (((uint8_t *)BigBuf) + FREE_BUFFER_OFFSET + (166*2)); - int resp3Len; - - // Acknowledge select - cascade 2 - uint8_t *resp3a = (((uint8_t *)BigBuf) + FREE_BUFFER_OFFSET + (166*3)); - int resp3aLen; - - // Response to a read request - not implemented atm - uint8_t *resp4 = (((uint8_t *)BigBuf) + FREE_BUFFER_OFFSET + (166*4)); -// int resp4Len; - - // Authenticate response - nonce - uint8_t *resp5 = (((uint8_t *)BigBuf) + FREE_BUFFER_OFFSET + (166*5)); - int resp5Len; - - // Authenticate response - nonce - uint8_t *resp6 = (((uint8_t *)BigBuf) + FREE_BUFFER_OFFSET + (166*6)); - int resp6Len; + uint8_t response6[] = { 0x04, 0x58, 0x00, 0x02, 0x00, 0x00 }; // dummy ATS (pseudo-ATR), answer to RATS + 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 querries 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<TAG_RESPONSE_COUNT; i++) { + prepare_allocated_tag_modulation(&responses[i]); + } uint8_t *receivedCmd = (((uint8_t *)BigBuf) + RECV_CMD_OFFSET); int len; @@ -1052,130 +1097,121 @@ void SimulateIso14443aTag(int tagType, int uid_1st, int uid_2nd, byte_t* data) // Just to allow some checks int happened = 0; int happened2 = 0; - int cmdsRecvd = 0; - uint8_t* respdata = NULL; - int respsize = 0; -// uint8_t nack = 0x04; - - memset(receivedCmd, 0x44, RECV_CMD_SIZE); - - // Prepare the responses of the anticollision phase - // there will be not enough time to do this at the moment the reader sends it REQA - - // Answer to request - CodeIso14443aAsTag(response1, sizeof(response1)); - memcpy(resp1, ToSend, ToSendMax); resp1Len = ToSendMax; - - // Send our UID (cascade 1) - CodeIso14443aAsTag(response2, sizeof(response2)); - memcpy(resp2, ToSend, ToSendMax); resp2Len = ToSendMax; - - // Answer to select (cascade1) - CodeIso14443aAsTag(response3, sizeof(response3)); - memcpy(resp3, ToSend, ToSendMax); resp3Len = ToSendMax; - - // Send the cascade 2 2nd part of the uid - CodeIso14443aAsTag(response2a, sizeof(response2a)); - memcpy(resp2a, ToSend, ToSendMax); resp2aLen = ToSendMax; - - // Answer to select (cascade 2) - CodeIso14443aAsTag(response3a, sizeof(response3a)); - memcpy(resp3a, ToSend, ToSendMax); resp3aLen = ToSendMax; - - // Strange answer is an example of rare message size (3 bits) - CodeStrangeAnswerAsTag(); - memcpy(resp4, ToSend, ToSendMax);// resp4Len = ToSendMax; - - // Authentication answer (random nonce) - CodeIso14443aAsTag(response5, sizeof(response5)); - memcpy(resp5, ToSend, ToSendMax); resp5Len = ToSendMax; - - // dummy ATS (pseudo-ATR), answer to RATS - CodeIso14443aAsTag(response6, sizeof(response6)); - memcpy(resp6, ToSend, ToSendMax); resp6Len = ToSendMax; // We need to listen to the high-frequency, peak-detected path. SetAdcMuxFor(GPIO_MUXSEL_HIPKD); FpgaSetupSsc(); cmdsRecvd = 0; + tag_response_info_t* p_response; LED_A_ON(); for(;;) { + // Clean receive command buffer + memset(receivedCmd, 0x44, RECV_CMD_SIZE); if(!GetIso14443aCommandFromReader(receivedCmd, &len, RECV_CMD_SIZE)) { - DbpString("button press"); + DbpString("Button press"); break; } - if (tracing) { + if (tracing) { LogTrace(receivedCmd,len, 0, Uart.parityBits, TRUE); - } + } + + p_response = NULL; // doob - added loads of debug strings so we can see what the reader is saying to us during the sim as hi14alist is not populated // Okay, look at the command now. lastorder = order; if(receivedCmd[0] == 0x26) { // Received a REQUEST - resp = resp1; respLen = resp1Len; order = 1; - respdata = response1; - respsize = sizeof(response1); + p_response = &responses[0]; order = 1; } else if(receivedCmd[0] == 0x52) { // Received a WAKEUP - resp = resp1; respLen = resp1Len; order = 6; - respdata = response1; - respsize = sizeof(response1); + p_response = &responses[0]; order = 6; } else if(receivedCmd[1] == 0x20 && receivedCmd[0] == 0x93) { // Received request for UID (cascade 1) - resp = resp2; respLen = resp2Len; order = 2; - respdata = response2; - respsize = sizeof(response2); + p_response = &responses[1]; order = 2; } else if(receivedCmd[1] == 0x20 && receivedCmd[0] == 0x95) { // Received request for UID (cascade 2) - resp = resp2a; respLen = resp2aLen; order = 20; - respdata = response2a; - respsize = sizeof(response2a); + p_response = &responses[2]; order = 20; } else if(receivedCmd[1] == 0x70 && receivedCmd[0] == 0x93) { // Received a SELECT (cascade 1) - resp = resp3; respLen = resp3Len; order = 3; - respdata = response3; - respsize = sizeof(response3); + p_response = &responses[3]; order = 3; } else if(receivedCmd[1] == 0x70 && receivedCmd[0] == 0x95) { // Received a SELECT (cascade 2) - resp = resp3a; respLen = resp3aLen; order = 30; - respdata = response3a; - respsize = sizeof(response3a); + p_response = &responses[4]; order = 30; } else if(receivedCmd[0] == 0x30) { // Received a (plain) READ -// resp = resp4; respLen = resp4Len; order = 4; // Do nothing -// respdata = &nack; -// respsize = sizeof(nack); // 4-bit answer - EmSendCmdEx(data+(4*receivedCmd[0]),16,false); + EmSendCmdEx(data+(4*receivedCmd[0]),16,false); Dbprintf("Read request from reader: %x %x",receivedCmd[0],receivedCmd[1]); - // We already responded, do not send anything with the EmSendCmd14443aRaw() that is called below - respLen = 0; + // We already responded, do not send anything with the EmSendCmd14443aRaw() that is called below + p_response = NULL; } else if(receivedCmd[0] == 0x50) { // Received a HALT // DbpString("Reader requested we HALT!:"); - // Do not respond - resp = resp1; respLen = 0; order = 0; - respdata = NULL; - respsize = 0; + p_response = NULL; } else if(receivedCmd[0] == 0x60 || receivedCmd[0] == 0x61) { // Received an authentication request - resp = resp5; respLen = resp5Len; order = 7; - respdata = response5; - respsize = sizeof(response5); + p_response = &responses[5]; order = 7; } else if(receivedCmd[0] == 0xE0) { // Received a RATS request - resp = resp6; respLen = resp6Len; order = 70; - respdata = response6; - respsize = sizeof(response6); - } else { - if (order == 7 && len ==8) { - uint32_t nr = bytes_to_num(receivedCmd,4); - uint32_t ar = bytes_to_num(receivedCmd+4,4); - Dbprintf("Auth attempt {nr}{ar}: %08x %08x",nr,ar); - } else { - // Never seen this command before - Dbprintf("Received unknown command (len=%d):",len); - Dbhexdump(len,receivedCmd,false); + p_response = &responses[6]; order = 70; + } else if (order == 7 && len ==8) { // Received authentication request + uint32_t nr = bytes_to_num(receivedCmd,4); + uint32_t ar = bytes_to_num(receivedCmd+4,4); + Dbprintf("Auth attempt {nr}{ar}: %08x %08x",nr,ar); + } else { + // Check for ISO 14443A-4 compliant commands, look at left nibble + switch (receivedCmd[0]) { + + case 0x0B: + case 0x0A: { // IBlock (command) + dynamic_response_info.response[0] = receivedCmd[0]; + dynamic_response_info.response[1] = 0x00; + dynamic_response_info.response[2] = 0x90; + dynamic_response_info.response[3] = 0x00; + dynamic_response_info.response_n = 4; + } break; + + case 0x1A: + case 0x1B: { // Chaining command + dynamic_response_info.response[0] = 0xaa | ((receivedCmd[0]) & 1); + dynamic_response_info.response_n = 2; + } break; + + case 0xaa: + case 0xbb: { + dynamic_response_info.response[0] = receivedCmd[0] ^ 0x11; + dynamic_response_info.response_n = 2; + } break; + + case 0xBA: { // + memcpy(dynamic_response_info.response,"\xAB\x00",2); + dynamic_response_info.response_n = 2; + } break; + + case 0xCA: + case 0xC2: { // Readers sends deselect command + memcpy(dynamic_response_info.response,"\xCA\x00",2); + dynamic_response_info.response_n = 2; + } break; + + default: { + // Never seen this command before + Dbprintf("Received unknown command (len=%d):",len); + Dbhexdump(len,receivedCmd,false); + // Do not respond + dynamic_response_info.response_n = 0; + } break; + } + + if (dynamic_response_info.response_n > 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"); + break; + } + p_response = &dynamic_response_info; } - // Do not respond - resp = resp1; respLen = 0; order = 0; - respdata = NULL; - respsize = 0; } // Count number of wakeups received after a halt @@ -1193,137 +1229,97 @@ void SimulateIso14443aTag(int tagType, int uid_1st, int uid_2nd, byte_t* data) if(cmdsRecvd > 999) { DbpString("1000 commands later..."); break; - } else { - cmdsRecvd++; - } - - if(respLen > 0) { - EmSendCmd14443aRaw(resp, respLen, receivedCmd[0] == 0x52); - } - - if (tracing) { - if (respdata != NULL) { - LogTrace(respdata,respsize, 0, SwapBits(GetParity(respdata,respsize),respsize), FALSE); - } - if(traceLen > TRACE_SIZE) { - DbpString("Trace full"); - break; - } } - - memset(receivedCmd, 0x44, RECV_CMD_SIZE); + cmdsRecvd++; + + if (p_response != NULL) { + EmSendCmd14443aRaw(p_response->modulation, p_response->modulation_n, receivedCmd[0] == 0x52); + if (tracing) { + LogTrace(p_response->response,p_response->response_n,0,SwapBits(GetParity(p_response->response,p_response->response_n),p_response->response_n),FALSE); + if(traceLen > TRACE_SIZE) { + DbpString("Trace full"); +// break; + } + } + } } Dbprintf("%x %x %x", happened, happened2, cmdsRecvd); LED_A_OFF(); } -//----------------------------------------------------------------------------- -// Transmit the command (to the tag) that was placed in ToSend[]. -//----------------------------------------------------------------------------- -static void TransmitFor14443a(const uint8_t *cmd, int len, int *samples, int *wait) -{ - int c; - - FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_MOD); - - if (wait) - if(*wait < 10) - *wait = 10; - - for(c = 0; c < *wait;) { - if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) { - AT91C_BASE_SSC->SSC_THR = 0x00; // For exact timing! - c++; - } - if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) { - volatile uint32_t r = AT91C_BASE_SSC->SSC_RHR; - (void)r; - } - WDT_HIT(); - } - c = 0; - for(;;) { - if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) { - AT91C_BASE_SSC->SSC_THR = cmd[c]; - c++; - if(c >= len) { - break; - } - } - if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) { - volatile uint32_t r = AT91C_BASE_SSC->SSC_RHR; - (void)r; - } - WDT_HIT(); - } - if (samples) *samples = (c + *wait) << 3; +// 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; + } + } } //----------------------------------------------------------------------------- -// Code a 7-bit command without parity bit -// This is especially for 0x26 and 0x52 (REQA and WUPA) +// Transmit the command (to the tag) that was placed in ToSend[]. +// Parameter timing: +// if NULL: ignored +// if == 0: return time of transfer +// if != 0: delay transfer until time specified //----------------------------------------------------------------------------- -void ShortFrameFromReader(const uint8_t bt) +static void TransmitFor14443a(const uint8_t *cmd, int len, uint32_t *timing) { - int j; - int last; - uint8_t b; + int c; - ToSendReset(); + FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_MOD); - // Start of Communication (Seq. Z) - ToSend[++ToSendMax] = SEC_Z; - last = 0; - b = bt; - for(j = 0; j < 7; j++) { - if(b & 1) { - // Sequence X - ToSend[++ToSendMax] = SEC_X; - last = 1; + if (timing) { + if(*timing == 0) { // Measure time + *timing = (GetCountMifare() + 8) & 0xfffffff8; } else { - if(last == 0) { - // Sequence Z - ToSend[++ToSendMax] = SEC_Z; - } - else { - // Sequence Y - ToSend[++ToSendMax] = SEC_Y; - last = 0; - } + PrepareDelayedTransfer(*timing & 0x00000007); // Delay transfer (fine tuning - up to 7 MF clock ticks) } - b >>= 1; + if(MF_DBGLEVEL >= 4 && GetCountMifare() >= (*timing & 0xfffffff8)) Dbprintf("TransmitFor14443a: Missed timing"); + while(GetCountMifare() < (*timing & 0xfffffff8)); // Delay transfer (multiple of 8 MF clock ticks) } - // End of Communication - if(last == 0) { - // Sequence Z - ToSend[++ToSendMax] = SEC_Z; + for(c = 0; c < 10;) { // standard delay for each transfer (allow tag to be ready after last transmission) + if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) { + AT91C_BASE_SSC->SSC_THR = 0x00; + c++; + } } - else { - // Sequence Y - ToSend[++ToSendMax] = SEC_Y; - last = 0; + + c = 0; + for(;;) { + if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) { + AT91C_BASE_SSC->SSC_THR = cmd[c]; + c++; + if(c >= len) { + break; + } + } } - // Sequence Y - ToSend[++ToSendMax] = SEC_Y; - - // Just to be sure! - ToSend[++ToSendMax] = SEC_Y; - ToSend[++ToSendMax] = SEC_Y; - ToSend[++ToSendMax] = SEC_Y; - // Convert from last character reference to length - ToSendMax++; } //----------------------------------------------------------------------------- -// Prepare reader command to send to FPGA -// +// Prepare reader command (in bits, support short frames) to send to FPGA //----------------------------------------------------------------------------- -void CodeIso14443aAsReaderPar(const uint8_t * cmd, int len, uint32_t dwParity) +void CodeIso14443aBitsAsReaderPar(const uint8_t * cmd, int bits, uint32_t dwParity) { int i, j; int last; @@ -1335,12 +1331,14 @@ void CodeIso14443aAsReaderPar(const uint8_t * cmd, int len, uint32_t dwParity) ToSend[++ToSendMax] = SEC_Z; last = 0; + size_t bytecount = nbytes(bits); // Generate send structure for the data bits - for (i = 0; i < len; i++) { + 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 < 8; j++) { + for (j = 0; j < bitsleft; j++) { if (b & 1) { // Sequence X ToSend[++ToSendMax] = SEC_X; @@ -1358,19 +1356,22 @@ void CodeIso14443aAsReaderPar(const uint8_t * cmd, int len, uint32_t dwParity) b >>= 1; } - // Get the parity bit - if ((dwParity >> i) & 0x01) { - // Sequence X - ToSend[++ToSendMax] = SEC_X; - last = 1; - } else { - if (last == 0) { - // Sequence Z - ToSend[++ToSendMax] = SEC_Z; + // Only transmit (last) parity bit if we transmitted a complete byte + if (j == 8) { + // Get the parity bit + if ((dwParity >> i) & 0x01) { + // Sequence X + ToSend[++ToSendMax] = SEC_X; + last = 1; } else { - // Sequence Y - ToSend[++ToSendMax] = SEC_Y; - last = 0; + if (last == 0) { + // Sequence Z + ToSend[++ToSendMax] = SEC_Z; + } else { + // Sequence Y + ToSend[++ToSendMax] = SEC_Y; + last = 0; + } } } } @@ -1396,6 +1397,14 @@ void CodeIso14443aAsReaderPar(const uint8_t * cmd, int len, uint32_t dwParity) ToSendMax++; } +//----------------------------------------------------------------------------- +// Prepare reader command to send to FPGA +//----------------------------------------------------------------------------- +void CodeIso14443aAsReaderPar(const uint8_t * cmd, int len, uint32_t dwParity) +{ + CodeIso14443aBitsAsReaderPar(cmd,len*8,dwParity); +} + //----------------------------------------------------------------------------- // Wait for commands from reader // Stop when button is pressed (return 1) or field was gone (return 2) @@ -1561,7 +1570,7 @@ static int GetIso14443aAnswerFromTag(uint8_t *receivedResponse, int maxLen, int // 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 Demod.output = receivedResponse; Demod.len = 0; @@ -1574,10 +1583,10 @@ static int GetIso14443aAnswerFromTag(uint8_t *receivedResponse, int maxLen, int for(;;) { WDT_HIT(); - if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) { - AT91C_BASE_SSC->SSC_THR = 0x00; // To make use of exact timing of next command from reader!! - if (elapsed) (*elapsed)++; - } + // if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) { + // AT91C_BASE_SSC->SSC_THR = 0x00; // To make use of exact timing of next command from reader!! + // if (elapsed) (*elapsed)++; + // } if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) { if(c < iso14a_timeout) { c++; } else { return FALSE; } b = (uint8_t)AT91C_BASE_SSC->SSC_RHR; @@ -1593,43 +1602,29 @@ static int GetIso14443aAnswerFromTag(uint8_t *receivedResponse, int maxLen, int } } -void ReaderTransmitShort(const uint8_t* bt) +void ReaderTransmitBitsPar(uint8_t* frame, int bits, uint32_t par, uint32_t *timing) { - int wait = 0; - int samples = 0; - - ShortFrameFromReader(*bt); - - // Select the card - TransmitFor14443a(ToSend, ToSendMax, &samples, &wait); - - // Store reader command in buffer - if (tracing) LogTrace(bt,1,0,GetParity(bt,1),TRUE); -} - -void ReaderTransmitPar(uint8_t* frame, int len, uint32_t par) -{ - int wait = 0; - int samples = 0; - - // This is tied to other size changes - // uint8_t* frame_addr = ((uint8_t*)BigBuf) + 2024; - CodeIso14443aAsReaderPar(frame,len,par); + CodeIso14443aBitsAsReaderPar(frame,bits,par); + // Select the card - TransmitFor14443a(ToSend, ToSendMax, &samples, &wait); + TransmitFor14443a(ToSend, ToSendMax, timing); if(trigger) LED_A_ON(); - + // Store reader command in buffer - if (tracing) LogTrace(frame,len,0,par,TRUE); + if (tracing) LogTrace(frame,nbytes(bits),0,par,TRUE); } +void ReaderTransmitPar(uint8_t* frame, int len, uint32_t par, uint32_t *timing) +{ + ReaderTransmitBitsPar(frame,len*8,par, timing); +} -void ReaderTransmit(uint8_t* frame, int len) +void ReaderTransmit(uint8_t* frame, int len, uint32_t *timing) { // Generate parity and redirect - ReaderTransmitPar(frame,len,GetParity(frame,len)); + ReaderTransmitBitsPar(frame,len*8,GetParity(frame,len), timing); } int ReaderReceive(uint8_t* receivedAnswer) @@ -1655,117 +1650,116 @@ int ReaderReceivePar(uint8_t* receivedAnswer, uint32_t * parptr) * 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 = (((uint8_t *)BigBuf) + FREE_BUFFER_OFFSET); // was 3560 - tied to other size changes + 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 = (((uint8_t *)BigBuf) + FREE_BUFFER_OFFSET); // was 3560 - tied to other size changes byte_t uid_resp[4]; size_t uid_resp_len; - uint8_t sak = 0x04; // cascade uid - int cascade_level = 0; - int 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 - ReaderTransmitShort(wupa); - // Receive the ATQA - if(!ReaderReceive(resp)) return 0; + // 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)) return 0; // Dbprintf("atqa: %02x %02x",resp[0],resp[1]); - - if(p_hi14a_card) { - memcpy(p_hi14a_card->atqa, resp, 2); + + 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; + // 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)); - if (!ReaderReceive(resp)) return 0; - - // First backup the current uid + // SELECT_ALL + ReaderTransmit(sel_all,sizeof(sel_all), NULL); + if (!ReaderReceive(resp)) return 0; + + // First backup the current uid memcpy(uid_resp,resp,4); uid_resp_len = 4; // Dbprintf("uid: %02x %02x %02x %02x",uid_resp[0],uid_resp[1],uid_resp[2],uid_resp[3]); - - // calculate crypto UID - if(cuid_ptr) { - *cuid_ptr = bytes_to_num(uid_resp, 4); + + // calculate crypto UID. Always use last 4 Bytes. + if(cuid_ptr) { + *cuid_ptr = bytes_to_num(uid_resp, 4); } - // Construct SELECT UID command - memcpy(sel_uid+2,resp,5); - AppendCrc14443a(sel_uid,7); - ReaderTransmit(sel_uid,sizeof(sel_uid)); + // Construct SELECT UID command + memcpy(sel_uid+2,resp,5); + AppendCrc14443a(sel_uid,7); + ReaderTransmit(sel_uid,sizeof(sel_uid), NULL); - // Receive the SAK - if (!ReaderReceive(resp)) return 0; - sak = resp[0]; + // Receive the SAK + if (!ReaderReceive(resp)) return 0; + sak = resp[0]; // Test if more parts of the uid are comming 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 - memcpy(uid_ptr, uid_ptr + 1, 3); + memcpy(uid_resp, uid_resp + 1, 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; - } + if(p_hi14a_card) { + p_hi14a_card->sak = sak; + p_hi14a_card->ats_len = 0; + } - if( (sak & 0x20) == 0) { - return 2; // non iso14443a compliant tag + if( (sak & 0x20) == 0) { + return 2; // non iso14443a compliant tag } - // Request for answer to select + // Request for answer to select AppendCrc14443a(rats, 2); - ReaderTransmit(rats, sizeof(rats)); - + ReaderTransmit(rats, sizeof(rats), NULL); + if (!(len = ReaderReceive(resp))) 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; + 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() { - // Set up the synchronous serial port - FpgaSetupSsc(); + // Set up the synchronous serial port + FpgaSetupSsc(); // Start from off (no field generated) // Signal field is off with the appropriate LED - LED_D_OFF(); - FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); - SpinDelay(50); +// LED_D_OFF(); +// FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); + // SpinDelay(50); SetAdcMuxFor(GPIO_MUXSEL_HIPKD); @@ -1773,7 +1767,7 @@ void iso14443a_setup() { // Signal field is on with the appropriate LED LED_D_ON(); FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_MOD); - SpinDelay(50); + SpinDelay(7); // iso14443-3 specifies 5ms max. iso14a_timeout = 2048; //default } @@ -1787,7 +1781,7 @@ int iso14_apdu(uint8_t * cmd, size_t cmd_len, void * data) { memcpy(real_cmd+2, cmd, cmd_len); AppendCrc14443a(real_cmd,cmd_len+2); - ReaderTransmit(real_cmd, cmd_len+4); + ReaderTransmit(real_cmd, cmd_len+4, NULL); size_t len = ReaderReceive(data); uint8_t * data_bytes = (uint8_t *) data; if (!len) @@ -1814,21 +1808,26 @@ void ReaderIso14443a(UsbCommand * c) iso14a_command_t param = c->arg[0]; uint8_t * cmd = c->d.asBytes; size_t len = c->arg[1]; - uint32_t arg0 = 0; - byte_t buf[USB_CMD_DATA_SIZE]; + size_t lenbits = c->arg[2]; + uint32_t arg0 = 0; + byte_t buf[USB_CMD_DATA_SIZE]; - iso14a_clear_trace(); - iso14a_set_tracing(true); + if(param & ISO14A_CONNECT) { + iso14a_clear_trace(); + } + iso14a_set_tracing(true); if(param & ISO14A_REQUEST_TRIGGER) { - iso14a_set_trigger(1); - } + iso14a_set_trigger(1); + } if(param & ISO14A_CONNECT) { iso14443a_setup(); - arg0 = iso14443a_select_card(NULL,(iso14a_card_select_t*)buf,NULL); - cmd_send(CMD_ACK,arg0,0,0,buf,sizeof(iso14a_card_select_t)); -// UsbSendPacket((void *)ack, sizeof(UsbCommand)); + 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) { @@ -1842,7 +1841,6 @@ void ReaderIso14443a(UsbCommand * c) if(param & ISO14A_APDU) { arg0 = iso14_apdu(cmd, len, buf); cmd_send(CMD_ACK,arg0,0,0,buf,sizeof(buf)); -// UsbSendPacket((void *)ack, sizeof(UsbCommand)); } if(param & ISO14A_RAW) { @@ -1850,105 +1848,212 @@ void ReaderIso14443a(UsbCommand * c) AppendCrc14443a(cmd,len); len += 2; } - ReaderTransmit(cmd,len); + if(lenbits>0) { + ReaderTransmitBitsPar(cmd,lenbits,GetParity(cmd,lenbits/8), NULL); + } else { + ReaderTransmit(cmd,len, NULL); + } arg0 = ReaderReceive(buf); -// UsbSendPacket((void *)ack, sizeof(UsbCommand)); - cmd_send(CMD_ACK,arg0,0,0,buf,sizeof(buf)); + cmd_send(CMD_ACK,arg0,0,0,buf,sizeof(buf)); } if(param & ISO14A_REQUEST_TRIGGER) { - iso14a_set_trigger(0); - } + iso14a_set_trigger(0); + } 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 +} + + //----------------------------------------------------------------------------- -// Read an ISO 14443a tag. Send out commands and store answers. -// +// 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(uint32_t parameter) +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 = (((uint8_t *)BigBuf) + FREE_BUFFER_OFFSET); // was 3560 - tied to other size changes + uint8_t* receivedAnswer = (((uint8_t *)BigBuf) + FREE_BUFFER_OFFSET); traceLen = 0; tracing = false; - iso14443a_setup(); - - LED_A_ON(); - LED_B_OFF(); - LED_C_OFF(); - byte_t nt_diff = 0; - LED_A_OFF(); byte_t par = 0; //byte_t par_mask = 0xff; - byte_t par_low = 0; - int led_on = TRUE; - uint8_t uid[8]; + static byte_t par_low = 0; + bool led_on = TRUE; + uint8_t uid[10]; uint32_t cuid; - tracing = FALSE; - byte_t nt[4] = {0,0,0,0}; - byte_t nt_attacked[4], nt_noattack[4]; + uint32_t nt, previous_nt; + static uint32_t nt_attacked = 0; byte_t par_list[8] = {0,0,0,0,0,0,0,0}; byte_t ks_list[8] = {0,0,0,0,0,0,0,0}; - num_to_bytes(parameter, 4, nt_noattack); - int isOK = 0, isNULL = 0; - while(TRUE) - { - LED_C_OFF(); - FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); - SpinDelay(50); - FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_MOD); - LED_C_ON(); - SpinDelay(2); + 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) { + StartCountMifare(); + mf_nr_ar3 = 0; + iso14443a_setup(); + while((GetCountMifare() & 0xffff0000) != 0x10000); // wait for counter to reset and "warm up" + sync_time = GetCountMifare() & 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; + } + else { + // we were unsuccessful on a previous call. Try another READER nonce (first 3 parity bits remain the same) + // nt_attacked = prng_successor(nt_attacked, 1); + mf_nr_ar3++; + mf_nr_ar[3] = mf_nr_ar3; + par = 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)) continue; + if(!iso14443a_select_card(uid, NULL, &cuid)) { + if (MF_DBGLEVEL >= 1) Dbprintf("Mifare: Can't select card"); + continue; + } - // Transmit MIFARE_CLASSIC_AUTH - ReaderTransmit(mf_auth, sizeof(mf_auth)); + //keep the card active + FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_MOD); - // Receive the (16 bit) "random" nonce - if (!ReaderReceive(receivedAnswer)) continue; - memcpy(nt, receivedAnswer, 4); + // CodeIso14443aBitsAsReaderPar(mf_auth, sizeof(mf_auth)*8, GetParity(mf_auth, sizeof(mf_auth)*8)); - // Transmit reader nonce and reader answer - ReaderTransmitPar(mf_nr_ar, sizeof(mf_nr_ar),par); + sync_time = (sync_time & 0xfffffff8) + sync_cycles + catch_up_cycles; + catch_up_cycles = 0; - // Receive 4 bit answer - if (ReaderReceive(receivedAnswer)) - { - if ( (parameter != 0) && (memcmp(nt, nt_noattack, 4) == 0) ) continue; + // if we missed the sync time already, advance to the next nonce repeat + while(GetCountMifare() > sync_time) { + sync_time = (sync_time & 0xfffffff8) + sync_cycles; + } - isNULL = !(nt_attacked[0] == 0) && (nt_attacked[1] == 0) && (nt_attacked[2] == 0) && (nt_attacked[3] == 0); - if ( (isNULL != 0 ) && (memcmp(nt, nt_attacked, 4) != 0) ) continue; + // 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)) { + 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)) + { + catch_up_cycles = 8; // the PRNG is delayed by 8 cycles due to the NAC (4Bits = 0x05 encrypted) transfer + if (nt_diff == 0) { - LED_A_ON(); - memcpy(nt_attacked, nt, 4); - //par_mask = 0xf8; - par_low = par & 0x07; + par_low = par & 0x07; // 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] = par; ks_list[nt_diff] = receivedAnswer[0] ^ 0x05; @@ -1959,10 +2064,10 @@ void ReaderMifare(uint32_t parameter) } nt_diff = (nt_diff + 1) & 0x07; - mf_nr_ar[3] = nt_diff << 5; + mf_nr_ar[3] = (mf_nr_ar[3] & 0x1F) | (nt_diff << 5); par = par_low; } else { - if (nt_diff == 0) + if (nt_diff == 0 && first_try) { par++; } else { @@ -1971,31 +2076,27 @@ void ReaderMifare(uint32_t parameter) } } - LogTrace(nt, 4, 0, GetParity(nt, 4), TRUE); + LogTrace((const uint8_t *)&nt, 4, 0, GetParity((const uint8_t *)&nt, 4), TRUE); LogTrace(par_list, 8, 0, GetParity(par_list, 8), TRUE); LogTrace(ks_list, 8, 0, GetParity(ks_list, 8), TRUE); - byte_t buf[48]; -// UsbCommand ack = {CMD_ACK, {isOK, 0, 0}}; + mf_nr_ar[3] &= 0x1F; + + byte_t buf[28]; memcpy(buf + 0, uid, 4); - memcpy(buf + 4, nt, 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); - LED_B_ON(); - cmd_send(CMD_ACK,isOK,0,0,buf,48); -// UsbSendPacket((uint8_t *)&ack, sizeof(UsbCommand)); - LED_B_OFF(); + cmd_send(CMD_ACK,isOK,0,0,buf,28); // Thats it... FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); LEDsoff(); tracing = TRUE; - - if (MF_DBGLEVEL >= 1) DbpString("COMMAND mifare FINISHED"); } - //----------------------------------------------------------------------------- // MIFARE 1K simulate. // @@ -2572,4 +2673,4 @@ done: Dbprintf("maxDataLen=%x, Uart.state=%x, Uart.byteCnt=%x Uart.byteCntMax=%x", maxDataLen, Uart.state, Uart.byteCnt, Uart.byteCntMax); LEDsoff(); -} \ No newline at end of file +}