PrintAndLog("expected output: Target (BA) requires final LRC XOR byte value: 5A");
return 0;
}
+
+int usage_analyse_checksum(void) {
+ PrintAndLog("The bytes will be added with eachother and than limited with the applied mask");
+ PrintAndLog("Finally compute ones' complement of the least significant bytes");
+ PrintAndLog("");
+ PrintAndLog("Usage: analyse chksum [h] b <bytes> m <mask>");
+ PrintAndLog("Options:");
+ PrintAndLog(" h This help");
+ PrintAndLog(" b <bytes> bytes to calc missing XOR in a LCR");
+ PrintAndLog(" m <mask> bit mask to limit the outpuyt");
+ PrintAndLog("");
+ PrintAndLog("Samples:");
+ PrintAndLog(" analyse chksum b 137AF00A0A0D m FF");
+ PrintAndLog("expected output: 0x61");
+ return 0;
+}
+
+int usage_analyse_crc(void){
+ PrintAndLog("A stub method to test different crc implementations inside the PM3 sourcecode. Just because you figured out the poly, doesn't mean you get the desired output");
+ PrintAndLog("");
+ PrintAndLog("Usage: analyse crc [h] <bytes>");
+ PrintAndLog("Options:");
+ PrintAndLog(" h This help");
+ PrintAndLog(" <bytes> bytes to calc crc");
+ PrintAndLog("");
+ PrintAndLog("Samples:");
+ PrintAndLog(" analyse crc 137AF00A0A0D");
+ return 0;
+}
+
static uint8_t calculateLRC( uint8_t* bytes, uint8_t len) {
uint8_t LRC = 0;
for (uint8_t i = 0; i < len; i++)
LRC ^= bytes[i];
return LRC;
}
-
+
+static uint8_t calcSumCrumbAdd( uint8_t* bytes, uint8_t len, uint32_t mask) {
+ uint8_t sum = 0;
+ for (uint8_t i = 0; i < len; i++) {
+ sum += CRUMB(bytes[i], 0);
+ sum += CRUMB(bytes[i], 2);
+ sum += CRUMB(bytes[i], 4);
+ sum += CRUMB(bytes[i], 6);
+ }
+ sum &= mask;
+ return sum;
+}
+static uint8_t calcSumCrumbAddOnes( uint8_t* bytes, uint8_t len, uint32_t mask) {
+ return ~calcSumCrumbAdd(bytes, len, mask);
+}
+static uint8_t calcSumNibbleAdd( uint8_t* bytes, uint8_t len, uint32_t mask) {
+ uint8_t sum = 0;
+ for (uint8_t i = 0; i < len; i++) {
+ sum += NIBBLE_LOW(bytes[i]);
+ sum += NIBBLE_HIGH(bytes[i]);
+ }
+ sum &= mask;
+ return sum;
+}
+static uint8_t calcSumNibbleAddOnes( uint8_t* bytes, uint8_t len, uint32_t mask){
+ return ~calcSumNibbleAdd(bytes, len, mask);
+}
+
+static uint8_t calcSumByteAdd( uint8_t* bytes, uint8_t len, uint32_t mask) {
+ uint8_t sum = 0;
+ for (uint8_t i = 0; i < len; i++)
+ sum += bytes[i];
+ sum &= mask;
+ return sum;
+}
+// Ones complement
+static uint8_t calcSumByteAddOnes( uint8_t* bytes, uint8_t len, uint32_t mask) {
+ return ~calcSumByteAdd(bytes, len, mask);
+}
+
+static uint8_t calcSumByteSub( uint8_t* bytes, uint8_t len, uint32_t mask) {
+ uint8_t sum = 0;
+ for (uint8_t i = 0; i < len; i++)
+ sum -= bytes[i];
+ sum &= mask;
+ return sum;
+}
+static uint8_t calcSumByteSubOnes( uint8_t* bytes, uint8_t len, uint32_t mask){
+ return ~calcSumByteSub(bytes, len, mask);
+}
+static uint8_t calcSumNibbleSub( uint8_t* bytes, uint8_t len, uint32_t mask) {
+ uint8_t sum = 0;
+ for (uint8_t i = 0; i < len; i++) {
+ sum -= NIBBLE_LOW(bytes[i]);
+ sum -= NIBBLE_HIGH(bytes[i]);
+ }
+ sum &= mask;
+ return sum;
+}
+static uint8_t calcSumNibbleSubOnes( uint8_t* bytes, uint8_t len, uint32_t mask) {
+ return ~calcSumNibbleSub(bytes, len, mask);
+}
+
int CmdAnalyseLCR(const char *Cmd) {
uint8_t data[50];
char cmdp = param_getchar(Cmd, 0);
PrintAndLog("Target [%02X] requires final LRC XOR byte value: 0x%02X",data[len-1] ,finalXor);
return 0;
}
+int CmdAnalyseCRC(const char *Cmd) {
+
+ char cmdp = param_getchar(Cmd, 0);
+ if (strlen(Cmd) == 0 || cmdp == 'h' || cmdp == 'H') return usage_analyse_crc();
+
+ int len = strlen(Cmd);
+ if ( len & 1 ) return usage_analyse_crc();
+
+ // add 1 for null terminator.
+ uint8_t *data = malloc(len+1);
+ if ( data == NULL ) return 1;
+
+ if ( param_gethex(Cmd, 0, data, len)) {
+ free(data);
+ return usage_analyse_crc();
+ }
+ len >>= 1;
+
+ //PrintAndLog("\nTests with '%s' hex bytes", sprint_hex(data, len));
+
+ PrintAndLog("\nTests of reflection. Two current methods in source code");
+ PrintAndLog(" reflect(0x3e23L,3) is %04X == 0x3e26", reflect(0x3e23L,3) );
+ PrintAndLog(" SwapBits(0x3e23L,3) is %04X == 0x3e26", SwapBits(0x3e23L,3) );
+ PrintAndLog(" 0xB400 == %04X", reflect( (1 << 16 | 0xb400),16) );
+
+ //
+ // Test of CRC16, '123456789' string.
+ //
+ PrintAndLog("\nTests with '123456789' string");
+ uint8_t dataStr[] = { 0x31,0x32,0x33,0x34,0x35,0x36,0x37,0x38,0x39 };
+ uint8_t legic8 = CRC8Legic(dataStr, sizeof(dataStr));
+
+ PrintAndLog("LEGIC: CRC16: %X", CRC16Legic(dataStr, sizeof(dataStr), legic8));
+
+ //these below has been tested OK.
+ PrintAndLog("Confirmed CRC Implementations");
+ PrintAndLog("LEGIC: CRC8 : %X (0xC6 expected)", legic8);
+ PrintAndLog("MAXIM: CRC8 : %X (0xA1 expected)", CRC8Maxim(dataStr, sizeof(dataStr)));
+ PrintAndLog("DNP : CRC16: %X (0x82EA expected)", CRC16_DNP(dataStr, sizeof(dataStr)));
+ PrintAndLog("CCITT: CRC16: %X (0xE5CC expected)", CRC16_CCITT(dataStr, sizeof(dataStr)));
+
+ free(data);
+ return 0;
+}
+int CmdAnalyseCHKSUM(const char *Cmd){
+
+ uint8_t data[50];
+ uint8_t cmdp = 0;
+ uint32_t mask = 0xFF;
+ bool errors = false;
+ int len = 0;
+ memset(data, 0x0, sizeof(data));
+
+ while(param_getchar(Cmd, cmdp) != 0x00) {
+ switch(param_getchar(Cmd, cmdp)) {
+ case 'b':
+ case 'B':
+ param_gethex_ex(Cmd, cmdp+1, data, &len);
+ if ( len%2 ) errors = true;
+ len >>= 1;
+ cmdp += 2;
+ break;
+ case 'm':
+ case 'M':
+ mask = param_get32ex(Cmd, cmdp+1, 0, 16);
+ cmdp += 2;
+ break;
+ case 'h':
+ case 'H':
+ return usage_analyse_checksum();
+ default:
+ PrintAndLog("Unknown parameter '%c'", param_getchar(Cmd, cmdp));
+ errors = true;
+ break;
+ }
+ if(errors) break;
+ }
+ //Validations
+ if(errors) return usage_analyse_checksum();
+
+ PrintAndLog("\nByte Add | 0x%X", calcSumByteAdd(data, len, mask));
+ PrintAndLog("Nibble Add | 0x%X", calcSumNibbleAdd(data, len, mask));
+ PrintAndLog("Crumb Add | 0x%X", calcSumCrumbAdd(data, len, mask));
+
+ PrintAndLog("\nByte Subtract | 0x%X", calcSumByteSub(data, len, mask));
+ PrintAndLog("Nibble Subtract | 0x%X", calcSumNibbleSub(data, len, mask));
+
+ PrintAndLog("\nCHECKSUM - One's complement");
+ PrintAndLog("Byte Add | 0x%X", calcSumByteAddOnes(data, len, mask));
+ PrintAndLog("Nibble Add | 0x%X", calcSumNibbleAddOnes(data, len, mask));
+ PrintAndLog("Crumb Add | 0x%X", calcSumCrumbAddOnes(data, len, mask));
+
+ PrintAndLog("Byte Subtract | 0x%X", calcSumByteSubOnes(data, len, mask));
+ PrintAndLog("Nibble Subtract | 0x%X", calcSumNibbleSubOnes(data, len, mask));
+
+ return 0;
+}
int CmdAnalyseDates(const char *Cmd){
// look for datestamps in a given array of bytes
- PrintAndLog("To be implemented. If you feel to contribute!");
+ PrintAndLog("To be implemented. Feel free to contribute!");
return 0;
}
static command_t CommandTable[] = {
{"help", CmdHelp, 1, "This help"},
- {"lcr", CmdAnalyseLCR, 0, "Generate final byte for XOR LRC"},
- {"dates", CmdAnalyseDates, 0, "Look for datestamps in a given array of bytes"},
+ {"lcr", CmdAnalyseLCR, 1, "Generate final byte for XOR LRC"},
+ {"crc", CmdAnalyseCRC, 1, "Stub method for CRC evaluations"},
+ {"chksum", CmdAnalyseCHKSUM, 1, "Checksum with adding, masking and one's complement"},
+ {"dates", CmdAnalyseDates, 1, "Look for datestamps in a given array of bytes"},
{NULL, NULL, 0, NULL}
};
projects / proxmark3-svn / blobdiff