X-Git-Url: http://git.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/blobdiff_plain/3b33bda694bcd22e2ceb8c9ff052f8fd4b81e3e8..af1caf6e4a0ff82f1e562053c0c3868014c74dfb:/armsrc/iso14443a.c diff --git a/armsrc/iso14443a.c b/armsrc/iso14443a.c index 111d7139..3966d77a 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 parity bits + for (i = 0; i < iLen; i++) { + // and save them to a 32Bit word + 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 @@ -375,196 +375,176 @@ static RAMFUNC int MillerDecoding(int bit) } //============================================================================= -// ISO 14443 Type A - Manchester +// ISO 14443 Type A - Manchester decoder //============================================================================= +// Basics: +// The tag will modulate the reader field by asserting different loads to it. As a consequence, the voltage +// at the reader antenna will be modulated as well. The FPGA detects the modulation for us and would deliver e.g. the following: +// ........ 0 0 1 1 1 1 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 ....... +// The Manchester decoder needs to identify the following sequences: +// 4 ticks modulated followed by 4 ticks unmodulated: Sequence D = 1 (also used as "start of communication") +// 4 ticks unmodulated followed by 4 ticks modulated: Sequence E = 0 +// 8 ticks unmodulated: Sequence F = end of communication +// 8 ticks modulated: A collision. Save the collision position and treat as Sequence D +// Note 1: the bitstream may start at any time (either in first or second nibble within the parameter bit). We therefore need to sync. +// Note 2: parameter offset is used to determine the position of the parity bits (required for the anticollision command only) static tDemod Demod; -static RAMFUNC int ManchesterDecoding(int v) +inline RAMFUNC bool IsModulation(byte_t b) { - int bit; - int modulation; - //int error = 0; - - if(!Demod.buff) { - Demod.buff = 1; - Demod.buffer = v; - return FALSE; - } - else { - bit = Demod.buffer; - Demod.buffer = v; - } + if (b >= 5 || b == 3) // majority decision: 2 or more bits are set + return true; + else + return false; + +} - if(Demod.state==DEMOD_UNSYNCD) { - Demod.output[Demod.len] = 0xfa; - Demod.syncBit = 0; - //Demod.samples = 0; - Demod.posCount = 1; // This is the first half bit period, so after syncing handle the second part +inline RAMFUNC bool IsModulationNibble1(byte_t b) +{ + return IsModulation((b & 0xE0) >> 5); +} - if(bit & 0x08) { - Demod.syncBit = 0x08; - } +inline RAMFUNC bool IsModulationNibble2(byte_t b) +{ + return IsModulation((b & 0x0E) >> 1); +} - if(bit & 0x04) { - if(Demod.syncBit) { - bit <<= 4; +static RAMFUNC int ManchesterDecoding(int bit, uint16_t offset) +{ + + switch (Demod.state) { + + case DEMOD_UNSYNCD: // not yet synced + Demod.len = 0; // initialize number of decoded data bytes + Demod.bitCount = offset; // initialize number of decoded data bits + Demod.shiftReg = 0; // initialize shiftreg to hold decoded data bits + Demod.parityBits = 0; // initialize parity bits + Demod.collisionPos = 0; // Position of collision bit + + if (IsModulationNibble1(bit) + && !IsModulationNibble2(bit)) { // this is the start bit + Demod.samples = 8; + if(trigger) LED_A_OFF(); + Demod.state = DEMOD_MANCHESTER_DATA; + } else if (!IsModulationNibble1(bit) && IsModulationNibble2(bit)) { // this may be the first half of the start bit + Demod.samples = 4; + Demod.state = DEMOD_HALF_SYNCD; } - Demod.syncBit = 0x04; - } + break; - if(bit & 0x02) { - if(Demod.syncBit) { - bit <<= 2; - } - Demod.syncBit = 0x02; - } - if(bit & 0x01 && Demod.syncBit) { - Demod.syncBit = 0x01; - } - - if(Demod.syncBit) { - Demod.len = 0; - Demod.state = DEMOD_START_OF_COMMUNICATION; - Demod.sub = SUB_FIRST_HALF; - Demod.bitCount = 0; - Demod.shiftReg = 0; - Demod.parityBits = 0; - Demod.samples = 0; - if(Demod.posCount) { - if(trigger) LED_A_OFF(); - switch(Demod.syncBit) { - case 0x08: Demod.samples = 3; break; - case 0x04: Demod.samples = 2; break; - case 0x02: Demod.samples = 1; break; - case 0x01: Demod.samples = 0; break; + case DEMOD_HALF_SYNCD: + Demod.samples += 8; + if (IsModulationNibble1(bit)) { // error: this was not a start bit. + Demod.state = DEMOD_UNSYNCD; + } else { + if (IsModulationNibble2(bit)) { // modulation in first half + Demod.state = DEMOD_MOD_FIRST_HALF; + } else { // no modulation in first half + Demod.state = DEMOD_NOMOD_FIRST_HALF; } } - //error = 0; - } - } - else { - //modulation = bit & Demod.syncBit; - modulation = ((bit << 1) ^ ((Demod.buffer & 0x08) >> 3)) & Demod.syncBit; - - Demod.samples += 4; - - if(Demod.posCount==0) { - Demod.posCount = 1; - if(modulation) { - Demod.sub = SUB_FIRST_HALF; + break; + + + case DEMOD_MOD_FIRST_HALF: + Demod.samples += 8; + Demod.bitCount++; + if (IsModulationNibble1(bit)) { // modulation in both halfs - collision + if (!Demod.collisionPos) { + Demod.collisionPos = (Demod.len << 3) + Demod.bitCount; + } + } // modulation in first half only - Sequence D = 1 + Demod.shiftReg = (Demod.shiftReg >> 1) | 0x100; // add a 1 to the shiftreg + if(Demod.bitCount >= 9) { // if we decoded a full byte (including parity) + Demod.parityBits <<= 1; // make room for the parity bit + Demod.output[Demod.len++] = (Demod.shiftReg & 0xff); + Demod.parityBits |= ((Demod.shiftReg >> 8) & 0x01); // store parity bit + Demod.bitCount = 0; + Demod.shiftReg = 0; } - else { - Demod.sub = SUB_NONE; + if (IsModulationNibble2(bit)) { // modulation in first half + Demod.state = DEMOD_MOD_FIRST_HALF; + } else { // no modulation in first half + Demod.state = DEMOD_NOMOD_FIRST_HALF; } - } - else { - Demod.posCount = 0; - if(modulation && (Demod.sub == SUB_FIRST_HALF)) { - if(Demod.state!=DEMOD_ERROR_WAIT) { - Demod.state = DEMOD_ERROR_WAIT; - Demod.output[Demod.len] = 0xaa; - //error = 0x01; + break; + + + case DEMOD_NOMOD_FIRST_HALF: + if (IsModulationNibble1(bit)) { // modulation in second half only - Sequence E = 0 + Demod.bitCount++; + Demod.samples += 8; + Demod.shiftReg = (Demod.shiftReg >> 1); // add a 0 to the shiftreg + if(Demod.bitCount >= 9) { // if we decoded a full byte (including parity) + Demod.parityBits <<= 1; // make room for the new parity bit + Demod.output[Demod.len++] = (Demod.shiftReg & 0xff); + Demod.parityBits |= ((Demod.shiftReg >> 8) & 0x01); // store parity bit + Demod.bitCount = 0; + Demod.shiftReg = 0; } + } else { // no modulation in both halves - End of communication + Demod.samples += 4; + if(Demod.bitCount > 0) { // if we decoded bits + Demod.shiftReg >>= (9 - Demod.bitCount); // add the remaining decoded bits to the output + Demod.output[Demod.len++] = Demod.shiftReg & 0xff; + // No parity bit, so just shift a 0 + Demod.parityBits <<= 1; + } + Demod.state = DEMOD_UNSYNCD; // start from the beginning + return TRUE; // we are finished with decoding the raw data sequence } - else if(modulation) { - Demod.sub = SUB_SECOND_HALF; + if (IsModulationNibble2(bit)) { // modulation in first half + Demod.state = DEMOD_MOD_FIRST_HALF; + } else { // no modulation in first half + Demod.state = DEMOD_NOMOD_FIRST_HALF; } + break; + - switch(Demod.state) { - case DEMOD_START_OF_COMMUNICATION: - if(Demod.sub == SUB_FIRST_HALF) { - Demod.state = DEMOD_MANCHESTER_D; - } - else { - Demod.output[Demod.len] = 0xab; - Demod.state = DEMOD_ERROR_WAIT; - //error = 0x02; - } - break; - - case DEMOD_MANCHESTER_D: - case DEMOD_MANCHESTER_E: - if(Demod.sub == SUB_FIRST_HALF) { - Demod.bitCount++; - Demod.shiftReg = (Demod.shiftReg >> 1) ^ 0x100; - Demod.state = DEMOD_MANCHESTER_D; - } - else if(Demod.sub == SUB_SECOND_HALF) { - Demod.bitCount++; - Demod.shiftReg >>= 1; - Demod.state = DEMOD_MANCHESTER_E; + case DEMOD_MANCHESTER_DATA: + Demod.samples += 8; + if (IsModulationNibble1(bit)) { // modulation in first half + if (IsModulationNibble2(bit) & 0x0f) { // ... and in second half = collision + if (!Demod.collisionPos) { + Demod.collisionPos = (Demod.len << 3) + Demod.bitCount; } - else { - Demod.state = DEMOD_MANCHESTER_F; - } - break; - - case DEMOD_MANCHESTER_F: - // Tag response does not need to be a complete byte! - if(Demod.len > 0 || Demod.bitCount > 0) { - if(Demod.bitCount > 0) { - Demod.shiftReg >>= (9 - Demod.bitCount); - Demod.output[Demod.len] = Demod.shiftReg & 0xff; - Demod.len++; - // No parity bit, so just shift a 0 - Demod.parityBits <<= 1; - } - - Demod.state = DEMOD_UNSYNCD; - return TRUE; + } // modulation in first half only - Sequence D = 1 + Demod.bitCount++; + Demod.shiftReg = (Demod.shiftReg >> 1) | 0x100; // in both cases, add a 1 to the shiftreg + if(Demod.bitCount >= 9) { // if we decoded a full byte (including parity) + Demod.parityBits <<= 1; // make room for the parity bit + Demod.output[Demod.len++] = (Demod.shiftReg & 0xff); + Demod.parityBits |= ((Demod.shiftReg >> 8) & 0x01); // store parity bit + Demod.bitCount = 0; + Demod.shiftReg = 0; + } + } else { // no modulation in first half + if (IsModulationNibble2(bit)) { // and modulation in second half = Sequence E = 0 + Demod.bitCount++; + Demod.shiftReg = (Demod.shiftReg >> 1); // add a 0 to the shiftreg + if(Demod.bitCount >= 9) { // if we decoded a full byte (including parity) + Demod.parityBits <<= 1; // make room for the new parity bit + Demod.output[Demod.len++] = (Demod.shiftReg & 0xff); + Demod.parityBits |= ((Demod.shiftReg >> 8) & 0x01); // store parity bit + Demod.bitCount = 0; + Demod.shiftReg = 0; } - else { - Demod.output[Demod.len] = 0xad; - Demod.state = DEMOD_ERROR_WAIT; - //error = 0x03; + } else { // no modulation in both halves - End of communication + if(Demod.bitCount > 0) { // if we decoded bits + Demod.shiftReg >>= (9 - Demod.bitCount); // add the remaining decoded bits to the output + Demod.output[Demod.len++] = Demod.shiftReg & 0xff; + // No parity bit, so just shift a 0 + Demod.parityBits <<= 1; } - break; - - case DEMOD_ERROR_WAIT: - Demod.state = DEMOD_UNSYNCD; - break; - - default: - Demod.output[Demod.len] = 0xdd; - Demod.state = DEMOD_UNSYNCD; - break; - } - - if(Demod.bitCount>=9) { - Demod.output[Demod.len] = Demod.shiftReg & 0xff; - Demod.len++; - - Demod.parityBits <<= 1; - Demod.parityBits ^= ((Demod.shiftReg >> 8) & 0x01); - - Demod.bitCount = 0; - Demod.shiftReg = 0; + Demod.state = DEMOD_UNSYNCD; // start from the beginning + return TRUE; // we are finished with decoding the raw data sequence + } } + + } - /*if(error) { - Demod.output[Demod.len] = 0xBB; - Demod.len++; - Demod.output[Demod.len] = error & 0xFF; - Demod.len++; - Demod.output[Demod.len] = 0xBB; - Demod.len++; - Demod.output[Demod.len] = bit & 0xFF; - Demod.len++; - Demod.output[Demod.len] = Demod.buffer & 0xFF; - Demod.len++; - Demod.output[Demod.len] = Demod.syncBit & 0xFF; - Demod.len++; - Demod.output[Demod.len] = 0xBB; - Demod.len++; - return TRUE; - }*/ - - } - - } // end (state != UNSYNCED) - - return FALSE; + return FALSE; // not finished yet, need more data } //============================================================================= @@ -584,7 +564,7 @@ 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 @@ -691,7 +671,7 @@ void RAMFUNC SnoopIso14443a(uint8_t param) { LED_B_OFF(); } - if(ManchesterDecoding(data[0] & 0x0F)) { + if(ManchesterDecoding(data[0], 0)) { LED_B_ON(); if (!LogTrace(receivedResponse, Demod.len, 0 - Demod.samples, Demod.parityBits, FALSE)) break; @@ -775,54 +755,54 @@ 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 +835,8 @@ 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 +888,76 @@ 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 +1031,41 @@ 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 = NULL; - 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 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 @@ -1193,72 +1209,91 @@ 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(); } + +// prepare a delayed transfer. This simply shifts ToSend[] by a number +// of bits specified in the delay parameter. +void PrepareDelayedTransfer(uint16_t delay) +{ + uint8_t bitmask = 0; + uint8_t bits_to_shift = 0; + uint8_t bits_shifted = 0; + + delay &= 0x07; + if (delay) { + for (uint16_t i = 0; i < delay; i++) { + bitmask |= (0x01 << i); + } + ToSend[++ToSendMax] = 0x00; + for (uint16_t i = 0; i < ToSendMax; i++) { + bits_to_shift = ToSend[i] & bitmask; + ToSend[i] = ToSend[i] >> delay; + ToSend[i] = ToSend[i] | (bits_shifted << (8 - delay)); + bits_shifted = bits_to_shift; + } + } +} + //----------------------------------------------------------------------------- // Transmit the command (to the tag) that was placed in ToSend[]. +// Parameter timing: +// if NULL: ignored +// if == 0: return time of transfer +// if != 0: delay transfer until time specified //----------------------------------------------------------------------------- -static void TransmitFor14443a(const uint8_t *cmd, int len, int *samples, int *wait) +static void TransmitFor14443a(const uint8_t *cmd, int len, uint32_t *timing) { - int c; + int c; - FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_MOD); + 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(); - } + if (timing) { + if(*timing == 0) { // Measure time + *timing = (GetCountMifare() + 8) & 0xfffffff8; + } else { + PrepareDelayedTransfer(*timing & 0x00000007); // Delay transfer (fine tuning - up to 7 MF clock ticks) + } + if(MF_DBGLEVEL >= 4 && GetCountMifare() >= (*timing & 0xfffffff8)) Dbprintf("TransmitFor14443a: Missed timing"); + while(GetCountMifare() < (*timing & 0xfffffff8)); // Delay transfer (multiple of 8 MF clock ticks) + } + + 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++; + } + } + + c = 0; + for(;;) { + if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) { + AT91C_BASE_SSC->SSC_THR = cmd[c]; + c++; + if(c >= len) { + break; + } + } + } - 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; } //----------------------------------------------------------------------------- @@ -1503,105 +1538,106 @@ int EmSendCmdPar(uint8_t *resp, int respLen, uint32_t par){ //----------------------------------------------------------------------------- // Wait a certain time for tag response // If a response is captured return TRUE -// If it takes to long return FALSE +// If it takes too long return FALSE //----------------------------------------------------------------------------- -static int GetIso14443aAnswerFromTag(uint8_t *receivedResponse, int maxLen, int *samples, int *elapsed) //uint8_t *buffer +static int GetIso14443aAnswerFromTag(uint8_t *receivedResponse, uint16_t offset, int maxLen, int *samples) { - // buffer needs to be 512 bytes int c; - + // Set FPGA mode to "reader listen mode", no modulation (listen // only, since we are receiving, not transmitting). // Signal field is on with the appropriate LED LED_D_ON(); FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_LISTEN); - + // Now get the answer from the card Demod.output = receivedResponse; Demod.len = 0; Demod.state = DEMOD_UNSYNCD; uint8_t b; - if (elapsed) *elapsed = 0; c = 0; 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; - if(ManchesterDecoding((b>>4) & 0xf)) { - *samples = ((c - 1) << 3) + 4; - return TRUE; - } - if(ManchesterDecoding(b & 0x0f)) { - *samples = c << 3; + if(ManchesterDecoding(b, offset)) { + *samples = Demod.samples; return TRUE; } } } } -void ReaderTransmitBitsPar(uint8_t* frame, int bits, uint32_t par) +void ReaderTransmitBitsPar(uint8_t* frame, int bits, uint32_t par, uint32_t *timing) { - int wait = 0; - int samples = 0; - - // This is tied to other size changes - // uint8_t* frame_addr = ((uint8_t*)BigBuf) + 2024; + CodeIso14443aBitsAsReaderPar(frame,bits,par); - // Select the card - TransmitFor14443a(ToSend, ToSendMax, &samples, &wait); + // Send command to tag + TransmitFor14443a(ToSend, ToSendMax, timing); if(trigger) LED_A_ON(); - // Store reader command in buffer + // Log reader command in trace buffer if (tracing) LogTrace(frame,nbytes(bits),0,par,TRUE); } -void ReaderTransmitPar(uint8_t* frame, int len, uint32_t par) +void ReaderTransmitPar(uint8_t* frame, int len, uint32_t par, uint32_t *timing) +{ + ReaderTransmitBitsPar(frame,len*8,par, timing); +} + +void ReaderTransmitBits(uint8_t* frame, int len, uint32_t *timing) { - ReaderTransmitBitsPar(frame,len*8,par); + // Generate parity and redirect + ReaderTransmitBitsPar(frame,len,GetParity(frame,len/8), timing); } -void ReaderTransmit(uint8_t* frame, int len) +void ReaderTransmit(uint8_t* frame, int len, uint32_t *timing) { // Generate parity and redirect - ReaderTransmitBitsPar(frame,len*8,GetParity(frame,len)); + ReaderTransmitBitsPar(frame,len*8,GetParity(frame,len), timing); +} + +int ReaderReceiveOffset(uint8_t* receivedAnswer, uint16_t offset) +{ + int samples = 0; + if (!GetIso14443aAnswerFromTag(receivedAnswer,offset,160,&samples)) return FALSE; + if (tracing) LogTrace(receivedAnswer,Demod.len,samples,Demod.parityBits,FALSE); + if(samples == 0) return FALSE; + return Demod.len; } int ReaderReceive(uint8_t* receivedAnswer) { - int samples = 0; - if (!GetIso14443aAnswerFromTag(receivedAnswer,160,&samples,0)) return FALSE; - if (tracing) LogTrace(receivedAnswer,Demod.len,samples,Demod.parityBits,FALSE); - if(samples == 0) return FALSE; - return Demod.len; + return ReaderReceiveOffset(receivedAnswer, 0); } -int ReaderReceivePar(uint8_t* receivedAnswer, uint32_t * parptr) +int ReaderReceivePar(uint8_t *receivedAnswer, uint32_t *parptr) { - int samples = 0; - if (!GetIso14443aAnswerFromTag(receivedAnswer,160,&samples,0)) return FALSE; - if (tracing) LogTrace(receivedAnswer,Demod.len,samples,Demod.parityBits,FALSE); + int samples = 0; + if (!GetIso14443aAnswerFromTag(receivedAnswer,0,160,&samples)) return FALSE; + if (tracing) LogTrace(receivedAnswer,Demod.len,samples,Demod.parityBits,FALSE); *parptr = Demod.parityBits; - if(samples == 0) return FALSE; - return Demod.len; + if(samples == 0) return FALSE; + return Demod.len; } -/* performs iso14443a anticolision procedure +/* performs iso14443a anticollision procedure * fills the uid pointer unless NULL * fills resp_data unless NULL */ int iso14443a_select_card(byte_t* uid_ptr, iso14a_card_select_t* p_hi14a_card, uint32_t* cuid_ptr) { uint8_t wupa[] = { 0x52 }; // 0x26 - REQA 0x52 - WAKE-UP uint8_t sel_all[] = { 0x93,0x20 }; - uint8_t sel_uid[] = { 0x93,0x70,0x00,0x00,0x00,0x00,0x00,0x00,0x00 }; + uint8_t 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]; @@ -1612,20 +1648,20 @@ int iso14443a_select_card(byte_t* uid_ptr, iso14a_card_select_t* p_hi14a_card, u int len; // Broadcast for a card, WUPA (0x52) will force response from all cards in the field - ReaderTransmitBitsPar(wupa,7,0); + ReaderTransmitBitsPar(wupa,7,0, NULL); // Receive the ATQA if(!ReaderReceive(resp)) return 0; -// Dbprintf("atqa: %02x %02x",resp[0],resp[1]); - + // Dbprintf("atqa: %02x %02x",resp[0],resp[1]); + 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,0,8); + memset(uid_ptr,0,10); } // OK we will select at least at cascade 1, lets see if first byte of UID was 0x88 in @@ -1636,40 +1672,71 @@ int iso14443a_select_card(byte_t* uid_ptr, iso14a_card_select_t* p_hi14a_card, u sel_uid[0] = sel_all[0] = 0x93 + cascade_level * 2; // SELECT_ALL - ReaderTransmit(sel_all,sizeof(sel_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; + + if (Demod.collisionPos) { // we had a collision and need to construct the UID bit by bit + memset(uid_resp, 0, 4); + uint16_t uid_resp_bits = 0; + uint16_t collision_answer_offset = 0; + // anti-collision-loop: + while (Demod.collisionPos) { + Dbprintf("Multiple tags detected. Collision after Bit %d", Demod.collisionPos); + for (uint16_t i = collision_answer_offset; i < Demod.collisionPos; i++, uid_resp_bits++) { // add valid UID bits before collision point + uint16_t UIDbit = (resp[i/8] >> (i % 8)) & 0x01; + uid_resp[uid_resp_bits & 0xf8] |= UIDbit << (uid_resp_bits % 8); + } + uid_resp[uid_resp_bits/8] |= 1 << (uid_resp_bits % 8); // next time select the card(s) with a 1 in the collision position + uid_resp_bits++; + // construct anticollosion command: + sel_uid[1] = ((2 + uid_resp_bits/8) << 4) | (uid_resp_bits & 0x07); // length of data in bytes and bits + for (uint16_t i = 0; i <= uid_resp_bits/8; i++) { + sel_uid[2+i] = uid_resp[i]; + } + collision_answer_offset = uid_resp_bits%8; + ReaderTransmitBits(sel_uid, 16 + uid_resp_bits, NULL); + if (!ReaderReceiveOffset(resp, collision_answer_offset)) return 0; + } + // finally, add the last bits and BCC of the UID + for (uint16_t i = collision_answer_offset; i < (Demod.len-1)*8; i++, uid_resp_bits++) { + uint16_t UIDbit = (resp[i/8] >> (i%8)) & 0x01; + uid_resp[uid_resp_bits/8] |= UIDbit << (uid_resp_bits % 8); + } + + } else { // no collision, use the response to SELECT_ALL as current uid + memcpy(uid_resp,resp,4); + } + uid_resp_len = 4; // 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)); + sel_uid[1] = 0x70; // transmitting a full UID (1 Byte cmd, 1 Byte NVB, 4 Byte UID, 1 Byte BCC, 2 Bytes CRC) + memcpy(sel_uid+2,uid_resp,4); // the UID + sel_uid[6] = sel_uid[2] ^ sel_uid[3] ^ sel_uid[4] ^ sel_uid[5]; // calculate and add BCC + AppendCrc14443a(sel_uid,7); // calculate and add CRC + ReaderTransmit(sel_uid,sizeof(sel_uid), NULL); // Receive the SAK if (!ReaderReceive(resp)) return 0; sak = resp[0]; // Test if more parts of the uid are comming - if ((sak & 0x04) && uid_resp[0] == 0x88) { + 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_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; @@ -1687,28 +1754,28 @@ int iso14443a_select_card(byte_t* uid_ptr, iso14a_card_select_t* p_hi14a_card, u // 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; } 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); @@ -1716,8 +1783,9 @@ 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. + Demod.state = DEMOD_UNSYNCD; iso14a_timeout = 2048; //default } @@ -1730,7 +1798,7 @@ 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) @@ -1757,21 +1825,27 @@ 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) { @@ -1785,7 +1859,6 @@ 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) { @@ -1793,372 +1866,253 @@ 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(); } -#define TEST_LENGTH 100 -typedef struct mftest{ - uint8_t nt[8]; - uint8_t count; -}mftest ; - -/** - *@brief Tunes the mifare attack settings. This method checks the nonce entropy when - *using a specified timeout. - *Different cards behave differently, some cards require up to a second to power down (and thus reset - *token generator), other cards are fine with 50 ms. - * - * @param time - * @return the entropy. A value of 100 (%) means that every nonce was unique, while a value close to - *zero indicates a low entropy: the given timeout is sufficient to power down the card. - */ -int TuneMifare(int time) -{ - // Mifare AUTH - uint8_t mf_auth[] = { 0x60,0x00,0xf5,0x7b }; - uint8_t* receivedAnswer = (((uint8_t *)BigBuf) + FREE_BUFFER_OFFSET); - - iso14443a_setup(); - int TIME1=time; - int TIME2=2000; - uint8_t uid[8]; - uint32_t cuid; - byte_t nt[4]; - Dbprintf("Tuning... testing a delay of %d ms (press button to skip)",time); - - - mftest nt_values[TEST_LENGTH]; - int nt_size = 0; - int i = 0; - for(i = 0 ; i< 100 ; i++) - { - LED_C_OFF(); - FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); - SpinDelay(TIME1); - FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_MOD); - LED_C_ON(); - SpinDelayUs(TIME2); - if(!iso14443a_select_card(uid, NULL, &cuid)) continue; - - // Transmit MIFARE_CLASSIC_AUTH - ReaderTransmit(mf_auth, sizeof(mf_auth)); - - // Receive the (16 bit) "random" nonce - if (!ReaderReceive(receivedAnswer)) continue; - memcpy(nt, receivedAnswer, 4); - - //store it - int already_stored = 0; - for(int i = 0 ; i < nt_size && !already_stored; i++) - { - if( memcmp(nt, nt_values[i].nt, 4) == 0) - { - nt_values[i].count++; - already_stored = 1; - } - } - if(!already_stored) - { - mftest* ptr= &nt_values[nt_size++]; - //Clear it before use - memset(ptr, 0, sizeof(mftest)); - memcpy(ptr->nt, nt, 4); - ptr->count = 1; - } - if(BUTTON_PRESS()) - { - Dbprintf("Tuning aborted prematurely"); - break; - } - } - /* - for(int i = 0 ; i < nt_size;i++){ - mftest x = nt_values[i]; - Dbprintf("%d,%d,%d,%d : %d",x.nt[0],x.nt[1],x.nt[2],x.nt[3],x.count); - } - */ - int result = nt_size *100 / i; - Dbprintf(" ... results for %d ms : %d %",time, result); - return result; -} +// 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) { -//----------------------------------------------------------------------------- -// Read an ISO 14443a tag. Send out commands and store answers. -// -//----------------------------------------------------------------------------- -#define STATE_SIZE 100 -typedef struct AttackState{ - byte_t nt[4]; - byte_t par_list[8]; - byte_t ks_list[8]; - byte_t par; - byte_t par_low; - byte_t nt_diff; - uint8_t mf_nr_ar[8]; -} AttackState; - - -int continueAttack(AttackState* pState,uint8_t* receivedAnswer) -{ + uint16_t i; + uint32_t nttmp1, nttmp2; - // Transmit reader nonce and reader answer - ReaderTransmitPar(pState->mf_nr_ar, sizeof(pState->mf_nr_ar),pState->par); + if (nt1 == nt2) return 0; - // Receive 4 bit answer - int len = ReaderReceive(receivedAnswer); - if (!len) - { - if (pState->nt_diff == 0) - { - pState->par++; - } else { - pState->par = (((pState->par >> 3) + 1) << 3) | pState->par_low; - } - return 2; - } - if(pState->nt_diff == 0) - { - pState->par_low = pState->par & 0x07; - } - //Dbprintf("answer received, parameter (%d), (memcmp(nt, nt_no)=%d",parameter,memcmp(nt, nt_noattack, 4)); - //if ( (parameter != 0) && (memcmp(nt, nt_noattack, 4) == 0) ) continue; - //isNULL = 0;//|| !(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; - - //led_on = !led_on; - //if(led_on) LED_B_ON(); else LED_B_OFF(); - pState->par_list[pState->nt_diff] = pState->par; - pState->ks_list[pState->nt_diff] = receivedAnswer[0] ^ 0x05; - - // Test if the information is complete - if (pState->nt_diff == 0x07) { - return 0; - } - - pState->nt_diff = (pState->nt_diff + 1) & 0x07; - pState->mf_nr_ar[3] = pState->nt_diff << 5; - pState->par = pState->par_low; - return 1; + 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 } -void reportResults(uint8_t uid[8],AttackState *pState, int isOK) + +//----------------------------------------------------------------------------- +// Recover several bits of the cypher stream. This implements (first stages of) +// the algorithm described in "The Dark Side of Security by Obscurity and +// Cloning MiFare Classic Rail and Building Passes, Anywhere, Anytime" +// (article by Nicolas T. Courtois, 2009) +//----------------------------------------------------------------------------- +void ReaderMifare(bool first_try) { - LogTrace(pState->nt, 4, 0, GetParity(pState->nt, 4), TRUE); - LogTrace(pState->par_list, 8, 0, GetParity(pState->par_list, 8), TRUE); - LogTrace(pState->ks_list, 8, 0, GetParity(pState->ks_list, 8), TRUE); - - byte_t buf[48]; - memcpy(buf + 0, uid, 4); - if(pState != NULL) - { - memcpy(buf + 4, pState->nt, 4); - memcpy(buf + 8, pState->par_list, 8); - memcpy(buf + 16, pState->ks_list, 8); - } + // 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; - LED_B_ON(); - cmd_send(CMD_ACK,isOK,0,0,buf,48); - LED_B_OFF(); + uint8_t* receivedAnswer = (((uint8_t *)BigBuf) + FREE_BUFFER_OFFSET); + traceLen = 0; + tracing = false; - // Thats it... - FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); - LEDsoff(); - tracing = TRUE; + byte_t nt_diff = 0; + byte_t par = 0; + //byte_t par_mask = 0xff; + static byte_t par_low = 0; + bool led_on = TRUE; + uint8_t uid[10]; + uint32_t cuid; - if (MF_DBGLEVEL >= 1) DbpString("COMMAND mifare FINISHED"); -} + 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}; -void ReaderMifareBegin(uint32_t offset_time, uint32_t powerdown_time); - -/** - * @brief New implementation of ReaderMifare, the classic mifare attack. - * This implementation is backwards-compatible, but has some added parameters. - * @param c the usbcommand in complete - * c->arg[0] - nt_noattack (deprecated) - * c->arg[1] - offset_time us (0 => random) - * c->arg[2] - powerdown_time ms (0=> tuning) - * - */ -void ReaderMifare(UsbCommand *c) -{ - /* - * The 'no-attack' is not used anymore, with the introduction of - * state tables. Instead, we use an offset which is random. This means that we - * should not get stuck on a 'bad' nonce, so no-attack is not needed. - * Anyway, arg[0] is reserved for backwards compatibility - uint32_t nt_noattack_uint = c->arg[0]; - byte_t nt_noattack[4]; - num_to_bytes(parameter, 4, nt_noattack_uint); - - */ - /* - *IF, for some reason, you want to attack a specific nonce or whatever, - *you can specify the offset time yourself, in which case it won't be random. - * - * The offset time is microseconds, MICROSECONDS, not ms. - */ - uint32_t offset_time = c->arg[1]; - if(offset_time == 0) - { - //[Martin:]I would like to have used rand(), but linking problems prevented it - //offset_time = rand() % 4000; - //So instead, I found this nifty thingy, which seems to fit the bill - offset_time = GetTickCount() % 2000; - } - /* - * There is an implementation of tuning. Tuning will try to determine - * a good power-down time, which is different for different cards. - * If a value is specified from the packet, we won't do any tuning. - * A value of zero will initialize a tuning. - * The power-down time is milliseconds, that MILLI-seconds . - */ - uint32_t powerdown_time = c->arg[2]; - if(powerdown_time == 0) - { - //Tuning required - int entropy = 100; - int time = 25; - entropy = TuneMifare(time); - - while(entropy > 50 && time < 2000){ - //Increase timeout, but never more than 500ms at a time - time = MIN(time*2, time+500); - entropy = TuneMifare(time); - } - if(entropy > 50){ - Dbprintf("OBS! This card has high entropy (%d) and slow power-down. This may take a while", entropy); - } - powerdown_time = time; - } - //The actual attack - ReaderMifareBegin(offset_time, powerdown_time); -} -void ReaderMifareBegin(uint32_t offset_time, uint32_t powerdown_time) -{ - Dbprintf("Using power-down-time of %d ms, offset time %d us", powerdown_time, offset_time); - - /** - *Allocate our state-table and initialize with zeroes - **/ + 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; - AttackState states[STATE_SIZE] ; - //Dbprintf("Memory allocated ok! (%d bytes)",STATE_SIZE*sizeof(AttackState) ); - memset(states, 0, STATE_SIZE*sizeof(AttackState)); - // Mifare AUTH - uint8_t mf_auth[] = { 0x60,0x00,0xf5,0x7b }; - uint8_t* receivedAnswer = (((uint8_t *)BigBuf) + FREE_BUFFER_OFFSET); // was 3560 - tied to other size changes - traceLen = 0; - tracing = false; + 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; + } - iso14443a_setup(); LED_A_ON(); LED_B_OFF(); LED_C_OFF(); + + + for(uint16_t i = 0; TRUE; i++) { + + WDT_HIT(); - LED_A_OFF(); - uint8_t uid[8]; - uint32_t cuid; + // Test if the action was cancelled + if(BUTTON_PRESS()) { + break; + } + + LED_C_ON(); - byte_t nt[4]; - int nts_attacked= 0; - //Keeps track of progress (max value of nt_diff for our states) - int progress = 0; - int high_entropy_warning_issued = 0; - while(!BUTTON_PRESS()) - { - LED_C_OFF(); - FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); - SpinDelay(powerdown_time); + if(!iso14443a_select_card(uid, NULL, &cuid)) { + if (MF_DBGLEVEL >= 1) Dbprintf("Mifare: Can't select card"); + continue; + } + + //keep the card active FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_MOD); - LED_C_ON(); - SpinDelayUs(offset_time); - - if(!iso14443a_select_card(uid, NULL, &cuid)) continue; - - // Transmit MIFARE_CLASSIC_AUTH - ReaderTransmit(mf_auth, sizeof(mf_auth)); - - // Receive the (16 bit) "random" nonce - if (!ReaderReceive(receivedAnswer)) continue; - memcpy(nt, receivedAnswer, 4); - - //Now we have the NT. Check if this NT is already under attack - AttackState* pState = NULL; - int i = 0; - for(i = 0 ; i < nts_attacked && pState == NULL; i++) - { - if( memcmp(nt, states[i].nt, 4) == 0) - { - //we have it - pState = &states[i]; - //Dbprintf("Existing state found (%d)", i); - } - } - if(pState == NULL){ - if(nts_attacked < STATE_SIZE ) - { - //Initialize a new state - pState = &states[nts_attacked++]; - //Clear it before use - memset(pState, 0, sizeof(AttackState)); - memcpy(pState->nt, nt, 4); - i = nts_attacked; - //Dbprintf("New state created, nt="); - }else if(!high_entropy_warning_issued){ - /** - *If we wound up here, it means that the state table was eaten up by potential nonces. This could be fixed by - *increasing the size of the state buffer, however, it points to some other problem. Ideally, we should get the same nonce - *every time. Realistically we should get a few different nonces, but if we get more than 50, there is probably somehting - *else that is wrong. An attack using too high nonce entropy will take **LONG** time to finish. - */ - DbpString("WARNING: Nonce entropy is suspiciously high, something is wrong. Check timeouts (and perhaps increase STATE_SIZE)"); - high_entropy_warning_issued = 1; - } - } - if(pState == NULL) continue; - - int result = continueAttack(pState, receivedAnswer); - - if(result == 1){ - //One state progressed another step - if(pState->nt_diff > progress) - { - progress = pState->nt_diff; - //Alert the user - Dbprintf("Recovery progress: %d/8, NTs attacked: %d ", progress,nts_attacked ); - } - //Dbprintf("State increased to %d in state %d", pState->nt_diff, i); - } - else if(result == 2){ - //Dbprintf("Continue attack no answer, par is now %d", pState->par); - } - else if(result == 0){ - reportResults(uid,pState,1); - return; - } - } - reportResults(uid,NULL,0); + sync_time = (sync_time & 0xfffffff8) + sync_cycles + catch_up_cycles; + catch_up_cycles = 0; + + // if we missed the sync time already, advance to the next nonce repeat + while(GetCountMifare() > sync_time) { + sync_time = (sync_time & 0xfffffff8) + sync_cycles; + } + + // Transmit MIFARE_CLASSIC_AUTH at synctime. Should result in returning the same tag nonce (== nt_attacked) + ReaderTransmit(mf_auth, sizeof(mf_auth), &sync_time); + + // Receive the (4 Byte) "random" nonce + if (!ReaderReceive(receivedAnswer)) { + 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) + { + 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; + + // Test if the information is complete + if (nt_diff == 0x07) { + isOK = 1; + break; + } + + nt_diff = (nt_diff + 1) & 0x07; + mf_nr_ar[3] = (mf_nr_ar[3] & 0x1F) | (nt_diff << 5); + par = par_low; + } else { + if (nt_diff == 0 && first_try) + { + par++; + } else { + par = (((par >> 3) + 1) << 3) | par_low; + } + } + } + + 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); + + mf_nr_ar[3] &= 0x1F; + + byte_t buf[28]; + memcpy(buf + 0, uid, 4); + num_to_bytes(nt, 4, buf + 4); + memcpy(buf + 8, par_list, 8); + memcpy(buf + 16, ks_list, 8); + memcpy(buf + 24, mf_nr_ar, 4); + + cmd_send(CMD_ACK,isOK,0,0,buf,28); + + // Thats it... + FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); + LEDsoff(); + tracing = TRUE; } + //----------------------------------------------------------------------------- // MIFARE 1K simulate. // @@ -2181,7 +2135,7 @@ void Mifare1ksim(uint8_t arg0, uint8_t arg1, uint8_t arg2, uint8_t *datain) //uint32_t cardRn = 0; uint32_t cardRr = 0; uint32_t cuid = 0; - //uint32_t rn_enc = 0; + uint32_t rn_enc = 0; uint32_t ans = 0; uint32_t cardINTREG = 0; uint8_t cardINTBLOCK = 0; @@ -2359,8 +2313,8 @@ void Mifare1ksim(uint8_t arg0, uint8_t arg1, uint8_t arg2, uint8_t *datain) case MFEMUL_AUTH1:{ if (len == 8) { // --- crypto - //rn_enc = bytes_to_num(receivedCmd, 4); - //cardRn = rn_enc ^ crypto1_word(pcs, rn_enc , 1); + rn_enc = bytes_to_num(receivedCmd, 4); + crypto1_word(pcs, rn_enc , 1); cardRr = bytes_to_num(&receivedCmd[4], 4) ^ crypto1_word(pcs, 0, 0); // test if auth OK if (cardRr != prng_successor(nonce, 64)){ @@ -2707,7 +2661,7 @@ void RAMFUNC SniffMifare(uint8_t param) { Demod.state = DEMOD_UNSYNCD; } - if(ManchesterDecoding(data[0] & 0x0F)) { + if(ManchesterDecoding(data[0], 0)) { LED_C_INV(); if (MfSniffLogic(receivedResponse, Demod.len, Demod.parityBits, Demod.bitCount, FALSE)) break;