int i;
uint32_t dwPar = 0;
- // Generate the encrypted data
+ // Generate the parity bits
for (i = 0; i < iLen; i++) {
- // Save the encrypted parity bit
+ // and save them to a 32Bit word
dwPar |= ((OddByteParity[pbtCmd[i]]) << i);
}
return dwPar;
}
//=============================================================================
-// 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;
+ 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 if(Demod.sub == SUB_SECOND_HALF) {
- Demod.bitCount++;
- Demod.shiftReg >>= 1;
- Demod.state = DEMOD_MANCHESTER_E;
+ } // 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.state = DEMOD_MANCHESTER_F;
+ } 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_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;
- }
- else {
- Demod.output[Demod.len] = 0xad;
- Demod.state = DEMOD_ERROR_WAIT;
- //error = 0x03;
- }
- 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
}
//=============================================================================
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;
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 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.
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<TAG_RESPONSE_COUNT; i++) {
+ prepare_allocated_tag_modulation(&responses[i]);
+ }
uint8_t *receivedCmd = (((uint8_t *)BigBuf) + RECV_CMD_OFFSET);
int len;
// 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;
}
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);
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;
+ 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
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;
- }
}
+ cmdsRecvd++;
- memset(receivedCmd, 0x44, RECV_CMD_SIZE);
+ 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);
}
}
-
-
-
//-----------------------------------------------------------------------------
// Transmit the command (to the tag) that was placed in ToSend[].
// Parameter 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)
+ 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++;
//-----------------------------------------------------------------------------
// 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
Demod.state = DEMOD_UNSYNCD;
uint8_t b;
- if (elapsed) *elapsed = 0;
c = 0;
for(;;) {
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, uint32_t *timing)
{
-
+
CodeIso14443aBitsAsReaderPar(frame,bits,par);
- // Select the card
+ // 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);
}
ReaderTransmitBitsPar(frame,len*8,par, timing);
}
+void ReaderTransmitBits(uint8_t* frame, int len, uint32_t *timing)
+{
+ // Generate parity and redirect
+ ReaderTransmitBitsPar(frame,len,GetParity(frame,len/8), timing);
+}
+
void ReaderTransmit(uint8_t* frame, int len, uint32_t *timing)
{
// Generate parity and redirect
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];
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);
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. Always use last 4 Bytes.
+ // 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);
+ 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
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);
FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_MOD);
SpinDelay(7); // iso14443-3 specifies 5ms max.
+ Demod.state = DEMOD_UNSYNCD;
iso14a_timeout = 2048; //default
}
if(param & ISO14A_CONNECT) {
iso14a_clear_trace();
}
+
iso14a_set_tracing(true);
if(param & ISO14A_REQUEST_TRIGGER) {
//keep the card active
FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_MOD);
- // CodeIso14443aBitsAsReaderPar(mf_auth, sizeof(mf_auth)*8, GetParity(mf_auth, sizeof(mf_auth)*8));
-
sync_time = (sync_time & 0xfffffff8) + sync_cycles + catch_up_cycles;
catch_up_cycles = 0;
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;
projects / proxmark3-svn / blobdiff