//----------------------------------------------------------------------------- // This code is licensed to you under the terms of the GNU GPL, version 2 or, // at your option, any later version. See the LICENSE.txt file for the text of // the license. //----------------------------------------------------------------------------- // Hitag2 emulation (preliminary test version) // // (c) 2009 Henryk Plötz //----------------------------------------------------------------------------- // Hitag2 complete rewrite of the code // - Fixed modulation/encoding issues // - Rewrote code for transponder emulation // - Added snooping of transponder communication // - Added reader functionality // // (c) 2012 Roel Verdult //----------------------------------------------------------------------------- #include "../include/proxmark3.h" #include "apps.h" #include "util.h" #include "../include/hitag2.h" #include "string.h" static bool bQuiet; bool bCrypto; bool bAuthenticating; bool bPwd; bool bSuccessful; int LogTraceHitag(const uint8_t * btBytes, int iBits, int iSamples, uint32_t dwParity, int bReader) { // Return when trace is full if (traceLen >= TRACE_SIZE) return FALSE; // Trace the random, i'm curious rsamples += iSamples; trace[traceLen++] = ((rsamples >> 0) & 0xff); trace[traceLen++] = ((rsamples >> 8) & 0xff); trace[traceLen++] = ((rsamples >> 16) & 0xff); trace[traceLen++] = ((rsamples >> 24) & 0xff); if (!bReader) { trace[traceLen - 1] |= 0x80; } trace[traceLen++] = ((dwParity >> 0) & 0xff); trace[traceLen++] = ((dwParity >> 8) & 0xff); trace[traceLen++] = ((dwParity >> 16) & 0xff); trace[traceLen++] = ((dwParity >> 24) & 0xff); trace[traceLen++] = iBits; memcpy(trace + traceLen, btBytes, nbytes(iBits)); traceLen += nbytes(iBits); return TRUE; } struct hitag2_tag { uint32_t uid; enum { TAG_STATE_RESET = 0x01, // Just powered up, awaiting GetSnr TAG_STATE_ACTIVATING = 0x02 , // In activation phase (password mode), sent UID, awaiting reader password TAG_STATE_ACTIVATED = 0x03, // Activation complete, awaiting read/write commands TAG_STATE_WRITING = 0x04, // In write command, awaiting sector contents to be written } state; unsigned int active_sector; byte_t crypto_active; uint64_t cs; byte_t sectors[12][4]; }; static struct hitag2_tag tag = { .state = TAG_STATE_RESET, .sectors = { // Password mode: | Crypto mode: [0] = { 0x02, 0x4e, 0x02, 0x20}, // UID | UID [1] = { 0x4d, 0x49, 0x4b, 0x52}, // Password RWD | 32 bit LSB key [2] = { 0x20, 0xf0, 0x4f, 0x4e}, // Reserved | 16 bit MSB key, 16 bit reserved [3] = { 0x0e, 0xaa, 0x48, 0x54}, // Configuration, password TAG | Configuration, password TAG [4] = { 0x46, 0x5f, 0x4f, 0x4b}, // Data: F_OK [5] = { 0x55, 0x55, 0x55, 0x55}, // Data: UUUU [6] = { 0xaa, 0xaa, 0xaa, 0xaa}, // Data: .... [7] = { 0x55, 0x55, 0x55, 0x55}, // Data: UUUU [8] = { 0x00, 0x00, 0x00, 0x00}, // RSK Low [9] = { 0x00, 0x00, 0x00, 0x00}, // RSK High [10] = { 0x00, 0x00, 0x00, 0x00}, // RCF [11] = { 0x00, 0x00, 0x00, 0x00}, // SYNC }, }; //#define TRACE_LENGTH 3000 //uint8_t *trace = (uint8_t *) BigBuf; //int traceLen = 0; //int rsamples = 0; #define AUTH_TABLE_OFFSET FREE_BUFFER_OFFSET #define AUTH_TABLE_LENGTH FREE_BUFFER_SIZE byte_t* auth_table = (byte_t *)BigBuf+AUTH_TABLE_OFFSET; size_t auth_table_pos = 0; size_t auth_table_len = AUTH_TABLE_LENGTH; byte_t password[4]; byte_t NrAr[8]; byte_t key[8]; uint64_t cipher_state; /* Following is a modified version of cryptolib.com/ciphers/hitag2/ */ // Software optimized 48-bit Philips/NXP Mifare Hitag2 PCF7936/46/47/52 stream cipher algorithm by I.C. Wiener 2006-2007. // For educational purposes only. // No warranties or guarantees of any kind. // This code is released into the public domain by its author. // Basic macros: #define u8 uint8_t #define u32 uint32_t #define u64 uint64_t #define rev8(x) ((((x)>>7)&1)+((((x)>>6)&1)<<1)+((((x)>>5)&1)<<2)+((((x)>>4)&1)<<3)+((((x)>>3)&1)<<4)+((((x)>>2)&1)<<5)+((((x)>>1)&1)<<6)+(((x)&1)<<7)) #define rev16(x) (rev8 (x)+(rev8 (x>> 8)<< 8)) #define rev32(x) (rev16(x)+(rev16(x>>16)<<16)) #define rev64(x) (rev32(x)+(rev32(x>>32)<<32)) #define bit(x,n) (((x)>>(n))&1) #define bit32(x,n) ((((x)[(n)>>5])>>((n)))&1) #define inv32(x,i,n) ((x)[(i)>>5]^=((u32)(n))<<((i)&31)) #define rotl64(x, n) ((((u64)(x))<<((n)&63))+(((u64)(x))>>((0-(n))&63))) // Single bit Hitag2 functions: #define i4(x,a,b,c,d) ((u32)((((x)>>(a))&1)+(((x)>>(b))&1)*2+(((x)>>(c))&1)*4+(((x)>>(d))&1)*8)) static const u32 ht2_f4a = 0x2C79; // 0010 1100 0111 1001 static const u32 ht2_f4b = 0x6671; // 0110 0110 0111 0001 static const u32 ht2_f5c = 0x7907287B; // 0111 1001 0000 0111 0010 1000 0111 1011 static u32 _f20 (const u64 x) { u32 i5; i5 = ((ht2_f4a >> i4 (x, 1, 2, 4, 5)) & 1)* 1 + ((ht2_f4b >> i4 (x, 7,11,13,14)) & 1)* 2 + ((ht2_f4b >> i4 (x,16,20,22,25)) & 1)* 4 + ((ht2_f4b >> i4 (x,27,28,30,32)) & 1)* 8 + ((ht2_f4a >> i4 (x,33,42,43,45)) & 1)*16; return (ht2_f5c >> i5) & 1; } static u64 _hitag2_init (const u64 key, const u32 serial, const u32 IV) { u32 i; u64 x = ((key & 0xFFFF) << 32) + serial; for (i = 0; i < 32; i++) { x >>= 1; x += (u64) (_f20 (x) ^ (((IV >> i) ^ (key >> (i+16))) & 1)) << 47; } return x; } static u64 _hitag2_round (u64 *state) { u64 x = *state; x = (x >> 1) + ((((x >> 0) ^ (x >> 2) ^ (x >> 3) ^ (x >> 6) ^ (x >> 7) ^ (x >> 8) ^ (x >> 16) ^ (x >> 22) ^ (x >> 23) ^ (x >> 26) ^ (x >> 30) ^ (x >> 41) ^ (x >> 42) ^ (x >> 43) ^ (x >> 46) ^ (x >> 47)) & 1) << 47); *state = x; return _f20 (x); } static u32 _hitag2_byte (u64 * x) { u32 i, c; for (i = 0, c = 0; i < 8; i++) c += (u32) _hitag2_round (x) << (i^7); return c; } int hitag2_reset(void) { tag.state = TAG_STATE_RESET; tag.crypto_active = 0; return 0; } int hitag2_init(void) { // memcpy(&tag, &resetdata, sizeof(tag)); hitag2_reset(); return 0; } static void hitag2_cipher_reset(struct hitag2_tag *tag, const byte_t *iv) { uint64_t key = ((uint64_t)tag->sectors[2][2]) | ((uint64_t)tag->sectors[2][3] << 8) | ((uint64_t)tag->sectors[1][0] << 16) | ((uint64_t)tag->sectors[1][1] << 24) | ((uint64_t)tag->sectors[1][2] << 32) | ((uint64_t)tag->sectors[1][3] << 40); uint32_t uid = ((uint32_t)tag->sectors[0][0]) | ((uint32_t)tag->sectors[0][1] << 8) | ((uint32_t)tag->sectors[0][2] << 16) | ((uint32_t)tag->sectors[0][3] << 24); uint32_t iv_ = (((uint32_t)(iv[0]))) | (((uint32_t)(iv[1])) << 8) | (((uint32_t)(iv[2])) << 16) | (((uint32_t)(iv[3])) << 24); tag->cs = _hitag2_init(rev64(key), rev32(uid), rev32(iv_)); } static int hitag2_cipher_authenticate(uint64_t* cs, const byte_t *authenticator_is) { byte_t authenticator_should[4]; authenticator_should[0] = ~_hitag2_byte(cs); authenticator_should[1] = ~_hitag2_byte(cs); authenticator_should[2] = ~_hitag2_byte(cs); authenticator_should[3] = ~_hitag2_byte(cs); return (memcmp(authenticator_should, authenticator_is, 4) == 0); } static int hitag2_cipher_transcrypt(uint64_t* cs, byte_t *data, unsigned int bytes, unsigned int bits) { int i; for(i=0; i 36 */ #define HITAG_T_LOW 8 /* T_LOW should be 4..10 */ #define HITAG_T_0_MIN 15 /* T[0] should be 18..22 */ #define HITAG_T_1_MIN 25 /* T[1] should be 26..30 */ //#define HITAG_T_EOF 40 /* T_EOF should be > 36 */ #define HITAG_T_EOF 80 /* T_EOF should be > 36 */ #define HITAG_T_WAIT_1 200 /* T_wresp should be 199..206 */ #define HITAG_T_WAIT_2 90 /* T_wresp should be 199..206 */ #define HITAG_T_WAIT_MAX 300 /* bit more than HITAG_T_WAIT_1 + HITAG_T_WAIT_2 */ #define HITAG_T_TAG_ONE_HALF_PERIOD 10 #define HITAG_T_TAG_TWO_HALF_PERIOD 25 #define HITAG_T_TAG_THREE_HALF_PERIOD 41 #define HITAG_T_TAG_FOUR_HALF_PERIOD 57 #define HITAG_T_TAG_HALF_PERIOD 16 #define HITAG_T_TAG_FULL_PERIOD 32 #define HITAG_T_TAG_CAPTURE_ONE_HALF 13 #define HITAG_T_TAG_CAPTURE_TWO_HALF 25 #define HITAG_T_TAG_CAPTURE_THREE_HALF 41 #define HITAG_T_TAG_CAPTURE_FOUR_HALF 57 static void hitag_send_bit(int bit) { LED_A_ON(); // Reset clock for the next bit AT91C_BASE_TC0->TC_CCR = AT91C_TC_SWTRG; // Fixed modulation, earlier proxmark version used inverted signal if(bit == 0) { // Manchester: Unloaded, then loaded |__--| LOW(GPIO_SSC_DOUT); while(AT91C_BASE_TC0->TC_CV < T0*HITAG_T_TAG_HALF_PERIOD); HIGH(GPIO_SSC_DOUT); while(AT91C_BASE_TC0->TC_CV < T0*HITAG_T_TAG_FULL_PERIOD); } else { // Manchester: Loaded, then unloaded |--__| HIGH(GPIO_SSC_DOUT); while(AT91C_BASE_TC0->TC_CV < T0*HITAG_T_TAG_HALF_PERIOD); LOW(GPIO_SSC_DOUT); while(AT91C_BASE_TC0->TC_CV < T0*HITAG_T_TAG_FULL_PERIOD); } LED_A_OFF(); } static void hitag_send_frame(const byte_t* frame, size_t frame_len) { // Send start of frame for(size_t i=0; i<5; i++) { hitag_send_bit(1); } // Send the content of the frame for(size_t i=0; i> (7-(i%8)))&1); } // Drop the modulation LOW(GPIO_SSC_DOUT); } void hitag2_handle_reader_command(byte_t* rx, const size_t rxlen, byte_t* tx, size_t* txlen) { byte_t rx_air[HITAG_FRAME_LEN]; // Copy the (original) received frame how it is send over the air memcpy(rx_air,rx,nbytes(rxlen)); if(tag.crypto_active) { hitag2_cipher_transcrypt(&(tag.cs),rx,rxlen/8,rxlen%8); } // Reset the transmission frame length *txlen = 0; // Try to find out which command was send by selecting on length (in bits) switch (rxlen) { // Received 11000 from the reader, request for UID, send UID case 05: { // Always send over the air in the clear plaintext mode if(rx_air[0] != 0xC0) { // Unknown frame ? return; } *txlen = 32; memcpy(tx,tag.sectors[0],4); tag.crypto_active = 0; } break; // Read/Write command: ..xx x..y yy with yyy == ~xxx, xxx is sector number case 10: { unsigned int sector = (~( ((rx[0]<<2)&0x04) | ((rx[1]>>6)&0x03) ) & 0x07); // Verify complement of sector index if(sector != ((rx[0]>>3)&0x07)) { //DbpString("Transmission error (read/write)"); return; } switch (rx[0] & 0xC6) { // Read command: 11xx x00y case 0xC0: memcpy(tx,tag.sectors[sector],4); *txlen = 32; break; // Inverted Read command: 01xx x10y case 0x44: for (size_t i=0; i<4; i++) { tx[i] = tag.sectors[sector][i] ^ 0xff; } *txlen = 32; break; // Write command: 10xx x01y case 0x82: // Prepare write, acknowledge by repeating command memcpy(tx,rx,nbytes(rxlen)); *txlen = rxlen; tag.active_sector = sector; tag.state=TAG_STATE_WRITING; break; // Unknown command default: Dbprintf("Uknown command: %02x %02x",rx[0],rx[1]); return; break; } } break; // Writing data or Reader password case 32: { if(tag.state == TAG_STATE_WRITING) { // These are the sector contents to be written. We don't have to do anything else. memcpy(tag.sectors[tag.active_sector],rx,nbytes(rxlen)); tag.state=TAG_STATE_RESET; return; } else { // Received RWD password, respond with configuration and our password if(memcmp(rx,tag.sectors[1],4) != 0) { DbpString("Reader password is wrong"); return; } *txlen = 32; memcpy(tx,tag.sectors[3],4); } } break; // Received RWD authentication challenge and respnse case 64: { // Store the authentication attempt if (auth_table_len < (AUTH_TABLE_LENGTH-8)) { memcpy(auth_table+auth_table_len,rx,8); auth_table_len += 8; } // Reset the cipher state hitag2_cipher_reset(&tag,rx); // Check if the authentication was correct if(!hitag2_cipher_authenticate(&(tag.cs),rx+4)) { // The reader failed to authenticate, do nothing Dbprintf("auth: %02x%02x%02x%02x%02x%02x%02x%02x Failed!",rx[0],rx[1],rx[2],rx[3],rx[4],rx[5],rx[6],rx[7]); return; } // Succesful, but commented out reporting back to the Host, this may delay to much. // Dbprintf("auth: %02x%02x%02x%02x%02x%02x%02x%02x OK!",rx[0],rx[1],rx[2],rx[3],rx[4],rx[5],rx[6],rx[7]); // Activate encryption algorithm for all further communication tag.crypto_active = 1; // Use the tag password as response memcpy(tx,tag.sectors[3],4); *txlen = 32; } break; } // LogTraceHitag(rx,rxlen,0,0,false); // LogTraceHitag(tx,*txlen,0,0,true); if(tag.crypto_active) { hitag2_cipher_transcrypt(&(tag.cs), tx, *txlen/8, *txlen%8); } } static void hitag_reader_send_bit(int bit) { LED_A_ON(); // Reset clock for the next bit AT91C_BASE_TC0->TC_CCR = AT91C_TC_SWTRG; // Binary puls length modulation (BPLM) is used to encode the data stream // This means that a transmission of a one takes longer than that of a zero // Enable modulation, which means, drop the the field HIGH(GPIO_SSC_DOUT); // Wait for 4-10 times the carrier period while(AT91C_BASE_TC0->TC_CV < T0*6); // SpinDelayUs(8*8); // Disable modulation, just activates the field again LOW(GPIO_SSC_DOUT); if(bit == 0) { // Zero bit: |_-| while(AT91C_BASE_TC0->TC_CV < T0*22); // SpinDelayUs(16*8); } else { // One bit: |_--| while(AT91C_BASE_TC0->TC_CV < T0*28); // SpinDelayUs(22*8); } LED_A_OFF(); } static void hitag_reader_send_frame(const byte_t* frame, size_t frame_len) { // Send the content of the frame for(size_t i=0; i> (7-(i%8)))&1); } // Send EOF AT91C_BASE_TC0->TC_CCR = AT91C_TC_SWTRG; // Enable modulation, which means, drop the the field HIGH(GPIO_SSC_DOUT); // Wait for 4-10 times the carrier period while(AT91C_BASE_TC0->TC_CV < T0*6); // Disable modulation, just activates the field again LOW(GPIO_SSC_DOUT); } size_t blocknr; bool hitag2_password(byte_t* rx, const size_t rxlen, byte_t* tx, size_t* txlen) { // Reset the transmission frame length *txlen = 0; // Try to find out which command was send by selecting on length (in bits) switch (rxlen) { // No answer, try to resurrect case 0: { // Stop if there is no answer (after sending password) if (bPwd) { DbpString("Password failed!"); return false; } *txlen = 5; memcpy(tx,"\xc0",nbytes(*txlen)); } break; // Received UID, tag password case 32: { if (!bPwd) { *txlen = 32; memcpy(tx,password,4); bPwd = true; memcpy(tag.sectors[blocknr],rx,4); blocknr++; } else { if(blocknr == 1){ //store password in block1, the TAG answers with Block3, but we need the password in memory memcpy(tag.sectors[blocknr],tx,4); }else{ memcpy(tag.sectors[blocknr],rx,4); } blocknr++; if (blocknr > 7) { DbpString("Read succesful!"); bSuccessful = true; return false; } *txlen = 10; tx[0] = 0xc0 | (blocknr << 3) | ((blocknr^7) >> 2); tx[1] = ((blocknr^7) << 6); } } break; // Unexpected response default: { Dbprintf("Uknown frame length: %d",rxlen); return false; } break; } return true; } bool hitag2_crypto(byte_t* rx, const size_t rxlen, byte_t* tx, size_t* txlen) { // Reset the transmission frame length *txlen = 0; if(bCrypto) { hitag2_cipher_transcrypt(&cipher_state,rx,rxlen/8,rxlen%8); } // Try to find out which command was send by selecting on length (in bits) switch (rxlen) { // No answer, try to resurrect case 0: { // Stop if there is no answer while we are in crypto mode (after sending NrAr) if (bCrypto) { // Failed during authentication if (bAuthenticating) { DbpString("Authentication failed!"); return false; } else { // Failed reading a block, could be (read/write) locked, skip block and re-authenticate if (blocknr == 1) { // Write the low part of the key in memory memcpy(tag.sectors[1],key+2,4); } else if (blocknr == 2) { // Write the high part of the key in memory tag.sectors[2][0] = 0x00; tag.sectors[2][1] = 0x00; tag.sectors[2][2] = key[0]; tag.sectors[2][3] = key[1]; } else { // Just put zero's in the memory (of the unreadable block) memset(tag.sectors[blocknr],0x00,4); } blocknr++; bCrypto = false; } } else { *txlen = 5; memcpy(tx,"\xc0",nbytes(*txlen)); } } break; // Received UID, crypto tag answer case 32: { if (!bCrypto) { uint64_t ui64key = key[0] | ((uint64_t)key[1]) << 8 | ((uint64_t)key[2]) << 16 | ((uint64_t)key[3]) << 24 | ((uint64_t)key[4]) << 32 | ((uint64_t)key[5]) << 40; uint32_t ui32uid = rx[0] | ((uint32_t)rx[1]) << 8 | ((uint32_t)rx[2]) << 16 | ((uint32_t)rx[3]) << 24; cipher_state = _hitag2_init(rev64(ui64key), rev32(ui32uid), 0); memset(tx,0x00,4); memset(tx+4,0xff,4); hitag2_cipher_transcrypt(&cipher_state,tx+4,4,0); *txlen = 64; bCrypto = true; bAuthenticating = true; } else { // Check if we received answer tag (at) if (bAuthenticating) { bAuthenticating = false; } else { // Store the received block memcpy(tag.sectors[blocknr],rx,4); blocknr++; } if (blocknr > 7) { DbpString("Read succesful!"); bSuccessful = true; return false; } *txlen = 10; tx[0] = 0xc0 | (blocknr << 3) | ((blocknr^7) >> 2); tx[1] = ((blocknr^7) << 6); } } break; // Unexpected response default: { Dbprintf("Uknown frame length: %d",rxlen); return false; } break; } if(bCrypto) { // We have to return now to avoid double encryption if (!bAuthenticating) { hitag2_cipher_transcrypt(&cipher_state,tx,*txlen/8,*txlen%8); } } return true; } bool hitag2_authenticate(byte_t* rx, const size_t rxlen, byte_t* tx, size_t* txlen) { // Reset the transmission frame length *txlen = 0; // Try to find out which command was send by selecting on length (in bits) switch (rxlen) { // No answer, try to resurrect case 0: { // Stop if there is no answer while we are in crypto mode (after sending NrAr) if (bCrypto) { DbpString("Authentication failed!"); return false; } *txlen = 5; memcpy(tx,"\xc0",nbytes(*txlen)); } break; // Received UID, crypto tag answer case 32: { if (!bCrypto) { *txlen = 64; memcpy(tx,NrAr,8); bCrypto = true; } else { DbpString("Authentication succesful!"); // We are done... for now return false; } } break; // Unexpected response default: { Dbprintf("Uknown frame length: %d",rxlen); return false; } break; } return true; } bool hitag2_test_auth_attempts(byte_t* rx, const size_t rxlen, byte_t* tx, size_t* txlen) { // Reset the transmission frame length *txlen = 0; // Try to find out which command was send by selecting on length (in bits) switch (rxlen) { // No answer, try to resurrect case 0: { // Stop if there is no answer while we are in crypto mode (after sending NrAr) if (bCrypto) { Dbprintf("auth: %02x%02x%02x%02x%02x%02x%02x%02x Failed, removed entry!",NrAr[0],NrAr[1],NrAr[2],NrAr[3],NrAr[4],NrAr[5],NrAr[6],NrAr[7]); // Removing failed entry from authentiations table memcpy(auth_table+auth_table_pos,auth_table+auth_table_pos+8,8); auth_table_len -= 8; // Return if we reached the end of the authentiactions table bCrypto = false; if (auth_table_pos == auth_table_len) { return false; } // Copy the next authentication attempt in row (at the same position, b/c we removed last failed entry) memcpy(NrAr,auth_table+auth_table_pos,8); } *txlen = 5; memcpy(tx,"\xc0",nbytes(*txlen)); } break; // Received UID, crypto tag answer, or read block response case 32: { if (!bCrypto) { *txlen = 64; memcpy(tx,NrAr,8); bCrypto = true; } else { Dbprintf("auth: %02x%02x%02x%02x%02x%02x%02x%02x OK",NrAr[0],NrAr[1],NrAr[2],NrAr[3],NrAr[4],NrAr[5],NrAr[6],NrAr[7]); bCrypto = false; if ((auth_table_pos+8) == auth_table_len) { return false; } auth_table_pos += 8; memcpy(NrAr,auth_table+auth_table_pos,8); } } break; default: { Dbprintf("Uknown frame length: %d",rxlen); return false; } break; } return true; } void SnoopHitag(uint32_t type) { int frame_count; int response; int overflow; bool rising_edge; bool reader_frame; int lastbit; bool bSkip; int tag_sof; byte_t rx[HITAG_FRAME_LEN]; size_t rxlen=0; // Clean up trace and prepare it for storing frames iso14a_set_tracing(TRUE); iso14a_clear_trace(); auth_table_len = 0; auth_table_pos = 0; memset(auth_table, 0x00, AUTH_TABLE_LENGTH); DbpString("Starting Hitag2 snoop"); LED_D_ON(); // Set up eavesdropping mode, frequency divisor which will drive the FPGA // and analog mux selection. FpgaDownloadAndGo(FPGA_BITSTREAM_LF); FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_EDGE_DETECT); FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz SetAdcMuxFor(GPIO_MUXSEL_LOPKD); RELAY_OFF(); // Configure output pin that is connected to the FPGA (for modulating) AT91C_BASE_PIOA->PIO_OER = GPIO_SSC_DOUT; AT91C_BASE_PIOA->PIO_PER = GPIO_SSC_DOUT; // Disable modulation, we are going to eavesdrop, not modulate ;) LOW(GPIO_SSC_DOUT); // Enable Peripheral Clock for TIMER_CLOCK1, used to capture edges of the reader frames AT91C_BASE_PMC->PMC_PCER = (1 << AT91C_ID_TC1); AT91C_BASE_PIOA->PIO_BSR = GPIO_SSC_FRAME; // Disable timer during configuration AT91C_BASE_TC1->TC_CCR = AT91C_TC_CLKDIS; // Capture mode, defaul timer source = MCK/2 (TIMER_CLOCK1), TIOA is external trigger, // external trigger rising edge, load RA on rising edge of TIOA. uint32_t t1_channel_mode = AT91C_TC_CLKS_TIMER_DIV1_CLOCK | AT91C_TC_ETRGEDG_BOTH | AT91C_TC_ABETRG | AT91C_TC_LDRA_BOTH; AT91C_BASE_TC1->TC_CMR = t1_channel_mode; // Enable and reset counter AT91C_BASE_TC1->TC_CCR = AT91C_TC_CLKEN | AT91C_TC_SWTRG; // Reset the received frame, frame count and timing info memset(rx,0x00,sizeof(rx)); frame_count = 0; response = 0; overflow = 0; reader_frame = false; lastbit = 1; bSkip = true; tag_sof = 4; while(!BUTTON_PRESS()) { // Watchdog hit WDT_HIT(); // Receive frame, watch for at most T0*EOF periods while (AT91C_BASE_TC1->TC_CV < T0*HITAG_T_EOF) { // Check if rising edge in modulation is detected if(AT91C_BASE_TC1->TC_SR & AT91C_TC_LDRAS) { // Retrieve the new timing values int ra = (AT91C_BASE_TC1->TC_RA/T0); // Find out if we are dealing with a rising or falling edge rising_edge = (AT91C_BASE_PIOA->PIO_PDSR & GPIO_SSC_FRAME) > 0; // Shorter periods will only happen with reader frames if (!reader_frame && rising_edge && ra < HITAG_T_TAG_CAPTURE_ONE_HALF) { // Switch from tag to reader capture LED_C_OFF(); reader_frame = true; memset(rx,0x00,sizeof(rx)); rxlen = 0; } // Only handle if reader frame and rising edge, or tag frame and falling edge if (reader_frame != rising_edge) { overflow += ra; continue; } // Add the buffered timing values of earlier captured edges which were skipped ra += overflow; overflow = 0; if (reader_frame) { LED_B_ON(); // Capture reader frame if(ra >= HITAG_T_STOP) { if (rxlen != 0) { //DbpString("wierd0?"); } // Capture the T0 periods that have passed since last communication or field drop (reset) response = (ra - HITAG_T_LOW); } else if(ra >= HITAG_T_1_MIN ) { // '1' bit rx[rxlen / 8] |= 1 << (7-(rxlen%8)); rxlen++; } else if(ra >= HITAG_T_0_MIN) { // '0' bit rx[rxlen / 8] |= 0 << (7-(rxlen%8)); rxlen++; } else { // Ignore wierd value, is to small to mean anything } } else { LED_C_ON(); // Capture tag frame (manchester decoding using only falling edges) if(ra >= HITAG_T_EOF) { if (rxlen != 0) { //DbpString("wierd1?"); } // Capture the T0 periods that have passed since last communication or field drop (reset) // We always recieve a 'one' first, which has the falling edge after a half period |-_| response = ra-HITAG_T_TAG_HALF_PERIOD; } else if(ra >= HITAG_T_TAG_CAPTURE_FOUR_HALF) { // Manchester coding example |-_|_-|-_| (101) rx[rxlen / 8] |= 0 << (7-(rxlen%8)); rxlen++; rx[rxlen / 8] |= 1 << (7-(rxlen%8)); rxlen++; } else if(ra >= HITAG_T_TAG_CAPTURE_THREE_HALF) { // Manchester coding example |_-|...|_-|-_| (0...01) rx[rxlen / 8] |= 0 << (7-(rxlen%8)); rxlen++; // We have to skip this half period at start and add the 'one' the second time if (!bSkip) { rx[rxlen / 8] |= 1 << (7-(rxlen%8)); rxlen++; } lastbit = !lastbit; bSkip = !bSkip; } else if(ra >= HITAG_T_TAG_CAPTURE_TWO_HALF) { // Manchester coding example |_-|_-| (00) or |-_|-_| (11) if (tag_sof) { // Ignore bits that are transmitted during SOF tag_sof--; } else { // bit is same as last bit rx[rxlen / 8] |= lastbit << (7-(rxlen%8)); rxlen++; } } else { // Ignore wierd value, is to small to mean anything } } } } // Check if frame was captured if(rxlen > 0) { frame_count++; if (!LogTraceHitag(rx,rxlen,response,0,reader_frame)) { DbpString("Trace full"); break; } // Check if we recognize a valid authentication attempt if (nbytes(rxlen) == 8) { // Store the authentication attempt if (auth_table_len < (AUTH_TABLE_LENGTH-8)) { memcpy(auth_table+auth_table_len,rx,8); auth_table_len += 8; } } // Reset the received frame and response timing info memset(rx,0x00,sizeof(rx)); response = 0; reader_frame = false; lastbit = 1; bSkip = true; tag_sof = 4; overflow = 0; LED_B_OFF(); LED_C_OFF(); } else { // Save the timer overflow, will be 0 when frame was received overflow += (AT91C_BASE_TC1->TC_CV/T0); } // Reset the frame length rxlen = 0; // Reset the timer to restart while-loop that receives frames AT91C_BASE_TC1->TC_CCR = AT91C_TC_SWTRG; } LED_A_ON(); LED_B_OFF(); LED_C_OFF(); LED_D_OFF(); AT91C_BASE_TC1->TC_CCR = AT91C_TC_CLKDIS; AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKDIS; FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); LED_A_OFF(); // Dbprintf("frame received: %d",frame_count); // Dbprintf("Authentication Attempts: %d",(auth_table_len/8)); // DbpString("All done"); } void SimulateHitagTag(bool tag_mem_supplied, byte_t* data) { int frame_count; int response; int overflow; byte_t rx[HITAG_FRAME_LEN]; size_t rxlen=0; byte_t tx[HITAG_FRAME_LEN]; size_t txlen=0; bool bQuitTraceFull = false; bQuiet = false; // Clean up trace and prepare it for storing frames iso14a_set_tracing(TRUE); iso14a_clear_trace(); auth_table_len = 0; auth_table_pos = 0; memset(auth_table, 0x00, AUTH_TABLE_LENGTH); DbpString("Starting Hitag2 simulation"); LED_D_ON(); hitag2_init(); if (tag_mem_supplied) { DbpString("Loading hitag2 memory..."); memcpy((byte_t*)tag.sectors,data,48); } uint32_t block = 0; for (size_t i=0; i<12; i++) { for (size_t j=0; j<4; j++) { block <<= 8; block |= tag.sectors[i][j]; } Dbprintf("| %d | %08x |",i,block); } // Set up simulator mode, frequency divisor which will drive the FPGA // and analog mux selection. FpgaDownloadAndGo(FPGA_BITSTREAM_LF); FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_EDGE_DETECT); FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz SetAdcMuxFor(GPIO_MUXSEL_LOPKD); RELAY_OFF(); // Configure output pin that is connected to the FPGA (for modulating) AT91C_BASE_PIOA->PIO_OER = GPIO_SSC_DOUT; AT91C_BASE_PIOA->PIO_PER = GPIO_SSC_DOUT; // Disable modulation at default, which means release resistance LOW(GPIO_SSC_DOUT); // Enable Peripheral Clock for TIMER_CLOCK0, used to measure exact timing before answering AT91C_BASE_PMC->PMC_PCER = (1 << AT91C_ID_TC0); // Enable Peripheral Clock for TIMER_CLOCK1, used to capture edges of the reader frames AT91C_BASE_PMC->PMC_PCER = (1 << AT91C_ID_TC1); AT91C_BASE_PIOA->PIO_BSR = GPIO_SSC_FRAME; // Disable timer during configuration AT91C_BASE_TC1->TC_CCR = AT91C_TC_CLKDIS; // Capture mode, defaul timer source = MCK/2 (TIMER_CLOCK1), TIOA is external trigger, // external trigger rising edge, load RA on rising edge of TIOA. AT91C_BASE_TC1->TC_CMR = AT91C_TC_CLKS_TIMER_DIV1_CLOCK | AT91C_TC_ETRGEDG_RISING | AT91C_TC_ABETRG | AT91C_TC_LDRA_RISING; // Enable and reset counter AT91C_BASE_TC1->TC_CCR = AT91C_TC_CLKEN | AT91C_TC_SWTRG; // Reset the received frame, frame count and timing info memset(rx,0x00,sizeof(rx)); frame_count = 0; response = 0; overflow = 0; while(!BUTTON_PRESS()) { // Watchdog hit WDT_HIT(); // Receive frame, watch for at most T0*EOF periods while (AT91C_BASE_TC1->TC_CV < T0*HITAG_T_EOF) { // Check if rising edge in modulation is detected if(AT91C_BASE_TC1->TC_SR & AT91C_TC_LDRAS) { // Retrieve the new timing values int ra = (AT91C_BASE_TC1->TC_RA/T0) + overflow; overflow = 0; // Reset timer every frame, we have to capture the last edge for timing AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKEN | AT91C_TC_SWTRG; LED_B_ON(); // Capture reader frame if(ra >= HITAG_T_STOP) { if (rxlen != 0) { //DbpString("wierd0?"); } // Capture the T0 periods that have passed since last communication or field drop (reset) response = (ra - HITAG_T_LOW); } else if(ra >= HITAG_T_1_MIN ) { // '1' bit rx[rxlen / 8] |= 1 << (7-(rxlen%8)); rxlen++; } else if(ra >= HITAG_T_0_MIN) { // '0' bit rx[rxlen / 8] |= 0 << (7-(rxlen%8)); rxlen++; } else { // Ignore wierd value, is to small to mean anything } } } // Check if frame was captured if(rxlen > 4) { frame_count++; if (!bQuiet) { if (!LogTraceHitag(rx,rxlen,response,0,true)) { DbpString("Trace full"); if (bQuitTraceFull) { break; } else { bQuiet = true; } } } // Disable timer 1 with external trigger to avoid triggers during our own modulation AT91C_BASE_TC1->TC_CCR = AT91C_TC_CLKDIS; // Process the incoming frame (rx) and prepare the outgoing frame (tx) hitag2_handle_reader_command(rx,rxlen,tx,&txlen); // Wait for HITAG_T_WAIT_1 carrier periods after the last reader bit, // not that since the clock counts since the rising edge, but T_Wait1 is // with respect to the falling edge, we need to wait actually (T_Wait1 - T_Low) // periods. The gap time T_Low varies (4..10). All timer values are in // terms of T0 units while(AT91C_BASE_TC0->TC_CV < T0*(HITAG_T_WAIT_1-HITAG_T_LOW)); // Send and store the tag answer (if there is any) if (txlen) { // Transmit the tag frame hitag_send_frame(tx,txlen); // Store the frame in the trace if (!bQuiet) { if (!LogTraceHitag(tx,txlen,0,0,false)) { DbpString("Trace full"); if (bQuitTraceFull) { break; } else { bQuiet = true; } } } } // Reset the received frame and response timing info memset(rx,0x00,sizeof(rx)); response = 0; // Enable and reset external trigger in timer for capturing future frames AT91C_BASE_TC1->TC_CCR = AT91C_TC_CLKEN | AT91C_TC_SWTRG; LED_B_OFF(); } // Reset the frame length rxlen = 0; // Save the timer overflow, will be 0 when frame was received overflow += (AT91C_BASE_TC1->TC_CV/T0); // Reset the timer to restart while-loop that receives frames AT91C_BASE_TC1->TC_CCR = AT91C_TC_SWTRG; } LED_B_OFF(); LED_D_OFF(); AT91C_BASE_TC1->TC_CCR = AT91C_TC_CLKDIS; AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKDIS; FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); // Dbprintf("frame received: %d",frame_count); // Dbprintf("Authentication Attempts: %d",(auth_table_len/8)); // DbpString("All done"); } void ReaderHitag(hitag_function htf, hitag_data* htd) { int frame_count; int response; byte_t rx[HITAG_FRAME_LEN]; size_t rxlen=0; byte_t txbuf[HITAG_FRAME_LEN]; byte_t* tx = txbuf; size_t txlen=0; int lastbit; bool bSkip; int reset_sof; int tag_sof; int t_wait = HITAG_T_WAIT_MAX; bool bStop; bool bQuitTraceFull = false; FpgaDownloadAndGo(FPGA_BITSTREAM_LF); // Reset the return status bSuccessful = false; // Clean up trace and prepare it for storing frames iso14a_set_tracing(TRUE); iso14a_clear_trace(); DbpString("Starting Hitag reader family"); // Check configuration switch(htf) { case RHT2F_PASSWORD: { Dbprintf("List identifier in password mode"); memcpy(password,htd->pwd.password,4); blocknr = 0; bQuitTraceFull = false; bQuiet = false; bPwd = false; } break; case RHT2F_AUTHENTICATE: { DbpString("Authenticating using nr,ar pair:"); memcpy(NrAr,htd->auth.NrAr,8); Dbhexdump(8,NrAr,false); bQuiet = false; bCrypto = false; bAuthenticating = false; bQuitTraceFull = true; } break; case RHT2F_CRYPTO: { DbpString("Authenticating using key:"); memcpy(key,htd->crypto.key,6); Dbhexdump(6,key,false); blocknr = 0; bQuiet = false; bCrypto = false; bAuthenticating = false; bQuitTraceFull = true; } break; case RHT2F_TEST_AUTH_ATTEMPTS: { Dbprintf("Testing %d authentication attempts",(auth_table_len/8)); auth_table_pos = 0; memcpy(NrAr,auth_table,8); bQuitTraceFull = false; bQuiet = false; bCrypto = false; } break; default: { Dbprintf("Error, unknown function: %d",htf); return; } break; } LED_D_ON(); hitag2_init(); // Configure output and enable pin that is connected to the FPGA (for modulating) AT91C_BASE_PIOA->PIO_OER = GPIO_SSC_DOUT; AT91C_BASE_PIOA->PIO_PER = GPIO_SSC_DOUT; // Set fpga in edge detect with reader field, we can modulate as reader now FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_EDGE_DETECT | FPGA_LF_EDGE_DETECT_READER_FIELD); // Set Frequency divisor which will drive the FPGA and analog mux selection FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz SetAdcMuxFor(GPIO_MUXSEL_LOPKD); RELAY_OFF(); // Disable modulation at default, which means enable the field LOW(GPIO_SSC_DOUT); // Give it a bit of time for the resonant antenna to settle. SpinDelay(30); // Enable Peripheral Clock for TIMER_CLOCK0, used to measure exact timing before answering AT91C_BASE_PMC->PMC_PCER = (1 << AT91C_ID_TC0); // Enable Peripheral Clock for TIMER_CLOCK1, used to capture edges of the tag frames AT91C_BASE_PMC->PMC_PCER = (1 << AT91C_ID_TC1); AT91C_BASE_PIOA->PIO_BSR = GPIO_SSC_FRAME; // Disable timer during configuration AT91C_BASE_TC1->TC_CCR = AT91C_TC_CLKDIS; // Capture mode, defaul timer source = MCK/2 (TIMER_CLOCK1), TIOA is external trigger, // external trigger rising edge, load RA on falling edge of TIOA. AT91C_BASE_TC1->TC_CMR = AT91C_TC_CLKS_TIMER_DIV1_CLOCK | AT91C_TC_ETRGEDG_FALLING | AT91C_TC_ABETRG | AT91C_TC_LDRA_FALLING; // Enable and reset counters AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKEN | AT91C_TC_SWTRG; AT91C_BASE_TC1->TC_CCR = AT91C_TC_CLKEN | AT91C_TC_SWTRG; // Reset the received frame, frame count and timing info frame_count = 0; response = 0; lastbit = 1; bStop = false; // Tag specific configuration settings (sof, timings, etc.) if (htf < 10){ // hitagS settings reset_sof = 1; t_wait = 200; DbpString("Configured for hitagS reader"); } else if (htf < 20) { // hitag1 settings reset_sof = 1; t_wait = 200; DbpString("Configured for hitag1 reader"); } else if (htf < 30) { // hitag2 settings reset_sof = 4; t_wait = HITAG_T_WAIT_2; DbpString("Configured for hitag2 reader"); } else { Dbprintf("Error, unknown hitag reader type: %d",htf); return; } while(!bStop && !BUTTON_PRESS()) { // Watchdog hit WDT_HIT(); // Check if frame was captured and store it if(rxlen > 0) { frame_count++; if (!bQuiet) { if (!LogTraceHitag(rx,rxlen,response,0,false)) { DbpString("Trace full"); if (bQuitTraceFull) { break; } else { bQuiet = true; } } } } // By default reset the transmission buffer tx = txbuf; switch(htf) { case RHT2F_PASSWORD: { bStop = !hitag2_password(rx,rxlen,tx,&txlen); } break; case RHT2F_AUTHENTICATE: { bStop = !hitag2_authenticate(rx,rxlen,tx,&txlen); } break; case RHT2F_CRYPTO: { bStop = !hitag2_crypto(rx,rxlen,tx,&txlen); } break; case RHT2F_TEST_AUTH_ATTEMPTS: { bStop = !hitag2_test_auth_attempts(rx,rxlen,tx,&txlen); } break; default: { Dbprintf("Error, unknown function: %d",htf); return; } break; } // Send and store the reader command // Disable timer 1 with external trigger to avoid triggers during our own modulation AT91C_BASE_TC1->TC_CCR = AT91C_TC_CLKDIS; // Wait for HITAG_T_WAIT_2 carrier periods after the last tag bit before transmitting, // Since the clock counts since the last falling edge, a 'one' means that the // falling edge occured halfway the period. with respect to this falling edge, // we need to wait (T_Wait2 + half_tag_period) when the last was a 'one'. // All timer values are in terms of T0 units while(AT91C_BASE_TC0->TC_CV < T0*(t_wait+(HITAG_T_TAG_HALF_PERIOD*lastbit))); // Transmit the reader frame hitag_reader_send_frame(tx,txlen); // Enable and reset external trigger in timer for capturing future frames AT91C_BASE_TC1->TC_CCR = AT91C_TC_CLKEN | AT91C_TC_SWTRG; // Add transmitted frame to total count if(txlen > 0) { frame_count++; if (!bQuiet) { // Store the frame in the trace if (!LogTraceHitag(tx,txlen,HITAG_T_WAIT_2,0,true)) { if (bQuitTraceFull) { break; } else { bQuiet = true; } } } } // Reset values for receiving frames memset(rx,0x00,sizeof(rx)); rxlen = 0; lastbit = 1; bSkip = true; tag_sof = reset_sof; response = 0; // Receive frame, watch for at most T0*EOF periods while (AT91C_BASE_TC1->TC_CV < T0*HITAG_T_WAIT_MAX) { // Check if falling edge in tag modulation is detected if(AT91C_BASE_TC1->TC_SR & AT91C_TC_LDRAS) { // Retrieve the new timing values int ra = (AT91C_BASE_TC1->TC_RA/T0); // Reset timer every frame, we have to capture the last edge for timing AT91C_BASE_TC0->TC_CCR = AT91C_TC_SWTRG; LED_B_ON(); // Capture tag frame (manchester decoding using only falling edges) if(ra >= HITAG_T_EOF) { if (rxlen != 0) { //DbpString("wierd1?"); } // Capture the T0 periods that have passed since last communication or field drop (reset) // We always recieve a 'one' first, which has the falling edge after a half period |-_| response = ra-HITAG_T_TAG_HALF_PERIOD; } else if(ra >= HITAG_T_TAG_CAPTURE_FOUR_HALF) { // Manchester coding example |-_|_-|-_| (101) rx[rxlen / 8] |= 0 << (7-(rxlen%8)); rxlen++; rx[rxlen / 8] |= 1 << (7-(rxlen%8)); rxlen++; } else if(ra >= HITAG_T_TAG_CAPTURE_THREE_HALF) { // Manchester coding example |_-|...|_-|-_| (0...01) rx[rxlen / 8] |= 0 << (7-(rxlen%8)); rxlen++; // We have to skip this half period at start and add the 'one' the second time if (!bSkip) { rx[rxlen / 8] |= 1 << (7-(rxlen%8)); rxlen++; } lastbit = !lastbit; bSkip = !bSkip; } else if(ra >= HITAG_T_TAG_CAPTURE_TWO_HALF) { // Manchester coding example |_-|_-| (00) or |-_|-_| (11) if (tag_sof) { // Ignore bits that are transmitted during SOF tag_sof--; } else { // bit is same as last bit rx[rxlen / 8] |= lastbit << (7-(rxlen%8)); rxlen++; } } else { // Ignore wierd value, is to small to mean anything } } // We can break this loop if we received the last bit from a frame if (AT91C_BASE_TC1->TC_CV > T0*HITAG_T_EOF) { if (rxlen>0) break; } } } LED_B_OFF(); LED_D_OFF(); AT91C_BASE_TC1->TC_CCR = AT91C_TC_CLKDIS; AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKDIS; FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); Dbprintf("frame received: %d",frame_count); DbpString("All done"); cmd_send(CMD_ACK,bSuccessful,0,0,(byte_t*)tag.sectors,48); }