+void mf_crypto1_decrypt(struct Crypto1State *pcs, uint8_t *data, int len, bool isEncrypted){\r
+ uint8_t bt = 0;\r
+ int i;\r
+ \r
+ if (len != 1) {\r
+ for (i = 0; i < len; i++)\r
+ data[i] = crypto1_byte(pcs, 0x00, isEncrypted) ^ data[i];\r
+ } else {\r
+ bt = 0;\r
+ for (i = 0; i < 4; i++)\r
+ bt |= (crypto1_bit(pcs, 0, isEncrypted) ^ BIT(data[0], i)) << i;\r
+ \r
+ data[0] = bt;\r
+ }\r
+ return;\r
+}\r
+\r
+\r
+int mfTraceDecode(uint8_t *data_src, int len, uint32_t parity, bool wantSaveToEmlFile) {\r
+ uint8_t data[64];\r
+\r
+ if (traceState == TRACE_ERROR) return 1;\r
+ if (len > 64) {\r
+ traceState = TRACE_ERROR;\r
+ return 1;\r
+ }\r
+ \r
+ memcpy(data, data_src, len);\r
+ if ((traceCrypto1) && ((traceState == TRACE_IDLE) || (traceState > TRACE_AUTH_OK))) {\r
+ mf_crypto1_decrypt(traceCrypto1, data, len, 0);\r
+ PrintAndLog("dec> %s", sprint_hex(data, len));\r
+ AddLogHex(logHexFileName, "dec> ", data, len); \r
+ }\r
+ \r
+ switch (traceState) {\r
+ case TRACE_IDLE: \r
+ // check packet crc16!\r
+ if ((len >= 4) && (!CheckCrc14443(CRC_14443_A, data, len))) {\r
+ PrintAndLog("dec> CRC ERROR!!!");\r
+ AddLogLine(logHexFileName, "dec> ", "CRC ERROR!!!"); \r
+ traceState = TRACE_ERROR; // do not decrypt the next commands\r
+ return 1;\r
+ }\r
+ \r
+ // AUTHENTICATION\r
+ if ((len ==4) && ((data[0] == 0x60) || (data[0] == 0x61))) {\r
+ traceState = TRACE_AUTH1;\r
+ traceCurBlock = data[1];\r
+ traceCurKey = data[0] == 60 ? 1:0;\r
+ return 0;\r
+ }\r
+\r
+ // READ\r
+ if ((len ==4) && ((data[0] == 0x30))) {\r
+ traceState = TRACE_READ_DATA;\r
+ traceCurBlock = data[1];\r
+ return 0;\r
+ }\r
+\r
+ // WRITE\r
+ if ((len ==4) && ((data[0] == 0xA0))) {\r
+ traceState = TRACE_WRITE_OK;\r
+ traceCurBlock = data[1];\r
+ return 0;\r
+ }\r
+\r
+ // HALT\r
+ if ((len ==4) && ((data[0] == 0x50) && (data[1] == 0x00))) {\r
+ traceState = TRACE_ERROR; // do not decrypt the next commands\r
+ return 0;\r
+ }\r
+ \r
+ return 0;\r
+ break;\r
+ \r
+ case TRACE_READ_DATA: \r
+ if (len == 18) {\r
+ traceState = TRACE_IDLE;\r
+\r
+ if (isBlockTrailer(traceCurBlock)) {\r
+ memcpy(traceCard + traceCurBlock * 16 + 6, data + 6, 4);\r
+ } else {\r
+ memcpy(traceCard + traceCurBlock * 16, data, 16);\r
+ }\r
+ if (wantSaveToEmlFile) saveTraceCard();\r
+ return 0;\r
+ } else {\r
+ traceState = TRACE_ERROR;\r
+ return 1;\r
+ }\r
+ break;\r
+\r
+ case TRACE_WRITE_OK: \r
+ if ((len == 1) && (data[0] == 0x0a)) {\r
+ traceState = TRACE_WRITE_DATA;\r
+\r
+ return 0;\r
+ } else {\r
+ traceState = TRACE_ERROR;\r
+ return 1;\r
+ }\r
+ break;\r
+\r
+ case TRACE_WRITE_DATA: \r
+ if (len == 18) {\r
+ traceState = TRACE_IDLE;\r
+\r
+ memcpy(traceCard + traceCurBlock * 16, data, 16);\r
+ if (wantSaveToEmlFile) saveTraceCard();\r
+ return 0;\r
+ } else {\r
+ traceState = TRACE_ERROR;\r
+ return 1;\r
+ }\r
+ break;\r
+\r
+ case TRACE_AUTH1: \r
+ if (len == 4) {\r
+ traceState = TRACE_AUTH2;\r
+\r
+ nt = bytes_to_num(data, 4);\r
+ nt_par = parity;\r
+ return 0;\r
+ } else {\r
+ traceState = TRACE_ERROR;\r
+ return 1;\r
+ }\r
+ break;\r
+\r
+ case TRACE_AUTH2: \r
+ if (len == 8) {\r
+ traceState = TRACE_AUTH_OK;\r
+\r
+ nr_enc = bytes_to_num(data, 4);\r
+ ar_enc = bytes_to_num(data + 4, 4);\r
+ nr_ar_par = parity;\r
+ return 0;\r
+ } else {\r
+ traceState = TRACE_ERROR;\r
+ return 1;\r
+ }\r
+ break;\r
+\r
+ case TRACE_AUTH_OK: \r
+ if (len ==4) {\r
+ traceState = TRACE_IDLE;\r
+\r
+ at_enc = bytes_to_num(data, 4);\r
+ at_par = parity;\r
+ \r
+ // decode key here)\r
+ ks2 = ar_enc ^ prng_successor(nt, 64);\r
+ ks3 = at_enc ^ prng_successor(nt, 96);\r
+ revstate = lfsr_recovery64(ks2, ks3);\r
+ lfsr_rollback_word(revstate, 0, 0);\r
+ lfsr_rollback_word(revstate, 0, 0);\r
+ lfsr_rollback_word(revstate, nr_enc, 1);\r
+ lfsr_rollback_word(revstate, uid ^ nt, 0);\r
+ crypto1_get_lfsr(revstate, &lfsr);\r
+ printf("key> %x%x\n", (unsigned int)((lfsr & 0xFFFFFFFF00000000) >> 32), (unsigned int)(lfsr & 0xFFFFFFFF));\r
+ AddLogUint64(logHexFileName, "key> ", lfsr); \r
+ \r
+ int blockShift = ((traceCurBlock & 0xFC) + 3) * 16;\r
+ if (isBlockEmpty((traceCurBlock & 0xFC) + 3)) memcpy(traceCard + blockShift + 6, trailerAccessBytes, 4);\r
+ \r
+ if (traceCurKey) {\r
+ num_to_bytes(lfsr, 6, traceCard + blockShift + 10);\r
+ } else {\r
+ num_to_bytes(lfsr, 6, traceCard + blockShift);\r
+ }\r
+ if (wantSaveToEmlFile) saveTraceCard();\r
+\r
+ if (traceCrypto1) {\r
+ crypto1_destroy(traceCrypto1);\r
+ }\r
+ \r
+ // set cryptosystem state\r
+ traceCrypto1 = lfsr_recovery64(ks2, ks3);\r
+ \r
+// nt = crypto1_word(traceCrypto1, nt ^ uid, 1) ^ nt;\r
+\r
+ /* traceCrypto1 = crypto1_create(lfsr); // key in lfsr\r
+ crypto1_word(traceCrypto1, nt ^ uid, 0);\r
+ crypto1_word(traceCrypto1, ar, 1);\r
+ crypto1_word(traceCrypto1, 0, 0);\r
+ crypto1_word(traceCrypto1, 0, 0);*/\r
+ \r
+ return 0;\r
+ } else {\r
+ traceState = TRACE_ERROR;\r
+ return 1;\r
+ }\r
+ break;\r
+\r
+ default: \r
+ traceState = TRACE_ERROR;\r
+ return 1;\r
+ }\r
+\r
+ return 0;\r
+}\r