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https://github.com/RfidResearchGroup/proxmark3.git
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FIX: Added @marshmellow42 's fix for ASK/Biphase simulation on deviceside.
CHG: Added @marshmellow42 's refactoring of "gprox-II" demod.
This commit is contained in:
iceman1001
parent
547595784f
commit
c728b2b4cf
4 changed files with 33 additions and 45 deletions
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@ -628,7 +628,7 @@ static void biphaseSimBit(uint8_t c, int *n, uint8_t clock, uint8_t *phase)
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memset(dest+(*n), c ^ *phase, clock);
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*phase ^= 1;
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}
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*n += clock;
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}
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// args clock, ask/man or askraw, invert, transmission separator
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@ -646,7 +646,7 @@ void CmdASKsimTag(uint16_t arg1, uint16_t arg2, size_t size, uint8_t *BitStream)
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for (i=0; i<size; i++){
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biphaseSimBit(BitStream[i]^invert, &n, clk, &phase);
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}
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if (BitStream[0]==BitStream[size-1]){ //run a second set inverted to keep phase in check
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if (phase==1) { //run a second set inverted to keep phase in check
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for (i=0; i<size; i++){
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biphaseSimBit(BitStream[i]^invert, &n, clk, &phase);
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}
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@ -592,7 +592,7 @@ int Cmdaskbiphdemod(const char *Cmd)
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int CmdG_Prox_II_Demod(const char *Cmd)
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{
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if (!ASKbiphaseDemod(Cmd, FALSE)){
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if (g_debugMode) PrintAndLog("ASKbiphaseDemod failed 1st try");
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if (g_debugMode) PrintAndLog("Error gProxII: ASKbiphaseDemod failed 1st try");
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return 0;
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}
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size_t size = DemodBufferLen;
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@ -602,46 +602,32 @@ int CmdG_Prox_II_Demod(const char *Cmd)
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if (g_debugMode) PrintAndLog("Error gProxII_Demod");
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return 0;
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}
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//got a good demod
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uint32_t ByteStream[65] = {0x00};
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//got a good demod of 96 bits
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uint8_t ByteStream[8] = {0x00};
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uint8_t xorKey=0;
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uint8_t keyCnt=0;
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uint8_t bitCnt=0;
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uint8_t ByteCnt=0;
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size_t startIdx = ans + 6; //start after preamble
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for (size_t idx = 0; idx<size-6; idx++){
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if ((idx+1) % 5 == 0){
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//spacer bit - should be 0
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if (DemodBuffer[startIdx+idx] != 0) {
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if (g_debugMode) PrintAndLog("Error spacer not 0: %u, pos: %u", (unsigned int)DemodBuffer[startIdx+idx],(unsigned int)(startIdx+idx));
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size_t startIdx = ans + 6; //start after 6 bit preamble
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uint8_t bits_no_spacer[90];
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//so as to not mess with raw DemodBuffer copy to a new sample array
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memcpy(bits_no_spacer, DemodBuffer + startIdx, 90);
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// remove the 18 (90/5=18) parity bits (down to 72 bits (96-6-18=72))
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size_t bitLen = removeParity(bits_no_spacer, 0, 5, 3, 90); //source, startloc, paritylen, ptype, length_to_run
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if (bitLen != 72) {
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if (g_debugMode) PrintAndLog("Error gProxII: spacer removal did not produce 72 bits: %u, start: %u", bitLen, startIdx);
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return 0;
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}
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continue;
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}
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if (keyCnt<8){ //lsb first
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xorKey |= (DemodBuffer[startIdx+idx]<<keyCnt);
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keyCnt++;
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if (keyCnt==8 && g_debugMode) PrintAndLog("xorKey Found: %02x", xorKey);
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continue;
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}
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//lsb first
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ByteStream[ByteCnt] |= (DemodBuffer[startIdx+idx]<<bitCnt);
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bitCnt++;
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if (bitCnt % 8 == 0){
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if (g_debugMode) PrintAndLog("byte %u: %02x", (unsigned int)ByteCnt, ByteStream[ByteCnt]);
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bitCnt=0;
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ByteCnt++;
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}
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// get key and then get all 8 bytes of payload decoded
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xorKey = (uint8_t)bytebits_to_byteLSBF(bits_no_spacer, 8);
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for (size_t idx = 0; idx < 8; idx++) {
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ByteStream[idx] = ((uint8_t)bytebits_to_byteLSBF(bits_no_spacer+8 + (idx*8),8)) ^ xorKey;
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if (g_debugMode) PrintAndLog("byte %u after xor: %02x", (unsigned int)idx, ByteStream[idx]);
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}
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for (uint8_t i = 0; i < ByteCnt; i++){
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ByteStream[i] ^= xorKey; //xor
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if (g_debugMode) PrintAndLog("byte %u after xor: %02x", (unsigned int)i, ByteStream[i]);
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}
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//now ByteStream contains 64 bytes of decrypted raw tag data
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//now ByteStream contains 8 Bytes (64 bits) of decrypted raw tag data
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//
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uint8_t fmtLen = ByteStream[0]>>2;
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uint32_t FC = 0;
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uint32_t Card = 0;
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//get raw 96 bits to print
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uint32_t raw1 = bytebits_to_byte(DemodBuffer+ans,32);
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uint32_t raw2 = bytebits_to_byte(DemodBuffer+ans+32, 32);
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uint32_t raw3 = bytebits_to_byte(DemodBuffer+ans+64, 32);
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@ -649,13 +635,14 @@ int CmdG_Prox_II_Demod(const char *Cmd)
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if (fmtLen==36){
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FC = ((ByteStream[3] & 0x7F)<<7) | (ByteStream[4]>>1);
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Card = ((ByteStream[4]&1)<<19) | (ByteStream[5]<<11) | (ByteStream[6]<<3) | (ByteStream[7]>>5);
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PrintAndLog("G-Prox-II Found: FmtLen %d, FC %d, Card %d",fmtLen,FC,Card);
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PrintAndLog("G-Prox-II Found: FmtLen %d, FC %u, Card %u", (int)fmtLen, FC, Card);
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} else if(fmtLen==26){
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FC = ((ByteStream[3] & 0x7F)<<1) | (ByteStream[4]>>7);
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Card = ((ByteStream[4]&0x7F)<<9) | (ByteStream[5]<<1) | (ByteStream[6]>>7);
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PrintAndLog("G-Prox-II Found: FmtLen %d, FC %d, Card %d",fmtLen,FC,Card);
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PrintAndLog("G-Prox-II Found: FmtLen %d, FC %u, Card %u", (int)fmtLen, FC, Card);
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} else {
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PrintAndLog("Unknown G-Prox-II Fmt Found: FmtLen %d",fmtLen);
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PrintAndLog("Unknown G-Prox-II Fmt Found: FmtLen %d",(int)fmtLen);
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PrintAndLog("Decoded Raw: %s", sprint_hex(ByteStream, 8));
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}
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PrintAndLog("Raw: %08x%08x%08x", raw1,raw2,raw3);
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setDemodBuf(DemodBuffer+ans, 96, 0);
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@ -48,7 +48,7 @@ int GetGuardBits(uint32_t fc, uint32_t cn, uint8_t *guardBits) {
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time_t t;
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srand((unsigned) time(&t));
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//uint8_t xorKey = rand() % 0xFF;
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uint8_t xorKey = 0x6b;
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uint8_t xorKey = 0x66;
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uint8_t i;
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@ -68,7 +68,7 @@ uint8_t parityTest(uint32_t bits, uint8_t bitLen, uint8_t pType)
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//by marshmellow
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// takes a array of binary values, start position, length of bits per parity (includes parity bit),
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// Parity Type (1 for odd; 0 for even; 2 Always 1's), and binary Length (length to run)
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// Parity Type (1 for odd; 0 for even; 2 for Always 1's; 3 for Always 0's), and binary Length (length to run)
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size_t removeParity(uint8_t *BitStream, size_t startIdx, uint8_t pLen, uint8_t pType, size_t bLen)
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{
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uint32_t parityWd = 0;
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@ -80,10 +80,11 @@ size_t removeParity(uint8_t *BitStream, size_t startIdx, uint8_t pLen, uint8_t p
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}
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j--; // overwrite parity with next data
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// if parity fails then return 0
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if (pType == 2) { // then marker bit which should be a 1
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if (!BitStream[j]) return 0;
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} else {
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if (parityTest(parityWd, pLen, pType) == 0) return 0;
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switch (pType) {
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case 3: if (BitStream[j]==1) return 0; break; //should be 0 spacer bit
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case 2: if (BitStream[j]==0) return 0; break; //should be 1 spacer bit
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default: //test parity
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if (parityTest(parityWd, pLen, pType) == 0) return 0; break;
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}
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bitCnt+=(pLen-1);
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parityWd = 0;
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@ -96,6 +97,7 @@ size_t removeParity(uint8_t *BitStream, size_t startIdx, uint8_t pLen, uint8_t p
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// by marshmellow
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// takes a array of binary values, length of bits per parity (includes parity bit),
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// Parity Type (1 for odd; 0 for even; 2 Always 1's; 3 Always 0's), and binary Length (length to run)
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// Make sure *dest is long enough to store original sourceLen + #_of_parities_to_be_added
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size_t addParity(uint8_t *BitSource, uint8_t *dest, uint8_t sourceLen, uint8_t pLen, uint8_t pType)
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{
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uint32_t parityWd = 0;
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@ -114,7 +116,6 @@ size_t addParity(uint8_t *BitSource, uint8_t *dest, uint8_t sourceLen, uint8_t p
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dest[j++] = parityTest(parityWd, pLen-1, pType) ^ 1;
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break;
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}
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bitCnt += pLen;
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parityWd = 0;
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}
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