X-Git-Url: http://cvs.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/blobdiff_plain/79375850fded8543748afc75f60700484de6617d..940b282f5482842b17865703ef5c9d53e7abec5d:/client/mifarehost.c diff --git a/client/mifarehost.c b/client/mifarehost.c index c6c6877e..d204bf12 100644 --- a/client/mifarehost.c +++ b/client/mifarehost.c @@ -11,7 +11,7 @@ #include "mifarehost.h" #include -#include +#include #include #include @@ -23,6 +23,8 @@ #include "util.h" #include "iso14443crc.h" +#include "mifare.h" + // mifare tracer flags used in mfTraceDecode() #define TRACE_IDLE 0x00 #define TRACE_AUTH1 0x01 @@ -52,7 +54,7 @@ static uint32_t intersection(uint64_t *list1, uint64_t *list2) return 0; } uint64_t *p1, *p2, *p3; - p1 = p3 = list1; + p1 = p3 = list1; p2 = list2; while ( *p1 != -1 && *p2 != -1 ) { @@ -98,7 +100,7 @@ static uint32_t nonce2key(uint32_t uid, uint32_t nt, uint32_t nr, uint64_t par_i } keylist = (uint64_t*)states; - + for (i = 0; keylist[i]; i++) { lfsr_rollback_word(states+i, uid^nt, 0); crypto1_get_lfsr(states+i, &key_recovered); @@ -128,16 +130,16 @@ int mfDarkside(uint64_t *key) printf("Press button on the proxmark3 device to abort both proxmark3 and client.\n"); printf("-------------------------------------------------------------------------\n"); - + while (true) { clearCommandBuffer(); SendCommand(&c); - + //flush queue while (ukbhit()) { int c = getchar(); (void) c; } - + // wait cycle while (true) { printf("."); @@ -146,7 +148,7 @@ int mfDarkside(uint64_t *key) return -5; break; } - + UsbCommand resp; if (WaitForResponseTimeout(CMD_ACK, &resp, 1000)) { isOK = resp.arg[0]; @@ -160,7 +162,7 @@ int mfDarkside(uint64_t *key) nr = bytes_to_num(resp.d.asBytes + 24, 4); break; } - } + } if (par_list == 0 && c.arg[0] == true) { PrintAndLog("Parity is all zero. Most likely this card sends NACK on every failed authentication."); @@ -171,7 +173,7 @@ int mfDarkside(uint64_t *key) keycount = nonce2key(uid, nt, nr, par_list, ks_list, &keylist); if (keycount == 0) { - PrintAndLog("Key not found (lfsr_common_prefix list is null). Nt=%08x", nt); + PrintAndLog("Key not found (lfsr_common_prefix list is null). Nt=%08x", nt); PrintAndLog("This is expected to happen in 25%% of all cases. Trying again with a different reader nonce..."); continue; } @@ -188,7 +190,7 @@ int mfDarkside(uint64_t *key) PrintAndLog("Found %u possible keys. Trying to authenticate with each of them ...\n", keycount); } else { PrintAndLog("Found a possible key. Trying to authenticate...\n"); - } + } *key = -1; uint8_t keyBlock[USB_CMD_DATA_SIZE]; @@ -205,8 +207,8 @@ int mfDarkside(uint64_t *key) if (!mfCheckKeys(0, 0, false, size, keyBlock, key)) { break; } - } - + } + if (*key != -1) { free(last_keylist); free(keylist); @@ -217,26 +219,55 @@ int mfDarkside(uint64_t *key) last_keylist = keylist; } } - + return 0; } int mfCheckKeys (uint8_t blockNo, uint8_t keyType, bool clear_trace, uint8_t keycnt, uint8_t * keyBlock, uint64_t * key){ - *key = 0; + *key = -1; - UsbCommand c = {CMD_MIFARE_CHKKEYS, {((blockNo & 0xff) | ((keyType&0xff)<<8)), clear_trace, keycnt}}; + UsbCommand c = {CMD_MIFARE_CHKKEYS, {((blockNo & 0xff) | ((keyType & 0xff) << 8)), clear_trace, keycnt}}; memcpy(c.d.asBytes, keyBlock, 6 * keycnt); SendCommand(&c); UsbCommand resp; - if (!WaitForResponseTimeout(CMD_ACK,&resp,3000)) return 1; + if (!WaitForResponseTimeout(CMD_ACK,&resp,3000)) return 1; if ((resp.arg[0] & 0xff) != 0x01) return 2; *key = bytes_to_num(resp.d.asBytes, 6); return 0; } +int mfCheckKeysSec(uint8_t sectorCnt, uint8_t keyType, uint8_t timeout14a, bool clear_trace, uint8_t keycnt, uint8_t * keyBlock, sector_t * e_sector){ + + uint8_t keyPtr = 0; + + if (e_sector == NULL) + return -1; + + UsbCommand c = {CMD_MIFARE_CHKKEYS, {((sectorCnt & 0xff) | ((keyType & 0xff) << 8)), (clear_trace | 0x02)|((timeout14a & 0xff) << 8), keycnt}}; + memcpy(c.d.asBytes, keyBlock, 6 * keycnt); + SendCommand(&c); + + UsbCommand resp; + if (!WaitForResponseTimeoutW(CMD_ACK, &resp, MAX(3000, 1000 + 13 * sectorCnt * keycnt * (keyType == 2 ? 2 : 1)), false)) return 1; // timeout: 13 ms / fail auth + if ((resp.arg[0] & 0xff) != 0x01) return 2; + + bool foundAKey = false; + for(int sec = 0; sec < sectorCnt; sec++){ + for(int keyAB = 0; keyAB < 2; keyAB++){ + keyPtr = *(resp.d.asBytes + keyAB * 40 + sec); + if (keyPtr){ + e_sector[sec].foundKey[keyAB] = true; + e_sector[sec].Key[keyAB] = bytes_to_num(keyBlock + (keyPtr - 1) * 6, 6); + foundAKey = true; + } + } + } + return foundAKey ? 0 : 3; +} + // Compare 16 Bits out of cryptostate int Compare16Bits(const void * a, const void * b) { if ((*(uint64_t*)b & 0x00ff000000ff0000) == (*(uint64_t*)a & 0x00ff000000ff0000)) return 0; @@ -244,7 +275,7 @@ int Compare16Bits(const void * a, const void * b) { else return -1; } -typedef +typedef struct { union { struct Crypto1State *slhead; @@ -274,11 +305,11 @@ void* nested_worker_thread(void *arg) statelist->len = p1 - statelist->head.slhead; statelist->tail.sltail = --p1; qsort(statelist->head.slhead, statelist->len, sizeof(uint64_t), Compare16Bits); - + return statelist->head.slhead; } -int mfnested(uint8_t blockNo, uint8_t keyType, uint8_t *key, uint8_t trgBlockNo, uint8_t trgKeyType, uint8_t *resultKey, bool calibrate) +int mfnested(uint8_t blockNo, uint8_t keyType, uint8_t *key, uint8_t trgBlockNo, uint8_t trgKeyType, uint8_t *resultKey, bool calibrate) { uint16_t i; uint32_t uid; @@ -286,10 +317,10 @@ int mfnested(uint8_t blockNo, uint8_t keyType, uint8_t *key, uint8_t trgBlockNo, StateList_t statelists[2]; struct Crypto1State *p1, *p2, *p3, *p4; - + // flush queue WaitForResponseTimeout(CMD_ACK, NULL, 100); - + UsbCommand c = {CMD_MIFARE_NESTED, {blockNo + keyType * 0x100, trgBlockNo + trgKeyType * 0x100, calibrate}}; memcpy(c.d.asBytes, key, 6); SendCommand(&c); @@ -301,10 +332,10 @@ int mfnested(uint8_t blockNo, uint8_t keyType, uint8_t *key, uint8_t trgBlockNo, if (resp.arg[0]) { return resp.arg[0]; // error during nested } - + memcpy(&uid, resp.d.asBytes, 4); PrintAndLog("uid:%08x trgbl=%d trgkey=%x", uid, (uint16_t)resp.arg[2] & 0xff, (uint16_t)resp.arg[2] >> 8); - + for (i = 0; i < 2; i++) { statelists[i].blockNo = resp.arg[2] & 0xff; statelists[i].keyType = (resp.arg[2] >> 8) & 0xff; @@ -312,16 +343,16 @@ int mfnested(uint8_t blockNo, uint8_t keyType, uint8_t *key, uint8_t trgBlockNo, memcpy(&statelists[i].nt, (void *)(resp.d.asBytes + 4 + i * 8 + 0), 4); memcpy(&statelists[i].ks1, (void *)(resp.d.asBytes + 4 + i * 8 + 4), 4); } - + // calc keys - + pthread_t thread_id[2]; - + // create and run worker threads for (i = 0; i < 2; i++) { pthread_create(thread_id + i, NULL, nested_worker_thread, &statelists[i]); } - + // wait for threads to terminate: for (i = 0; i < 2; i++) { pthread_join(thread_id[i], (void*)&statelists[i].head.slhead); @@ -331,7 +362,7 @@ int mfnested(uint8_t blockNo, uint8_t keyType, uint8_t *key, uint8_t trgBlockNo, // the first 16 Bits of the cryptostate already contain part of our key. // Create the intersection of the two lists based on these 16 Bits and // roll back the cryptostate - p1 = p3 = statelists[0].head.slhead; + p1 = p3 = statelists[0].head.slhead; p2 = p4 = statelists[1].head.slhead; while (p1 <= statelists[0].tail.sltail && p2 <= statelists[1].tail.sltail) { if (Compare16Bits(p1, p2) == 0) { @@ -382,10 +413,10 @@ int mfnested(uint8_t blockNo, uint8_t keyType, uint8_t *key, uint8_t trgBlockNo, break; } } - + free(statelists[0].head.slhead); free(statelists[1].head.slhead); - + return 0; } @@ -403,7 +434,7 @@ int mfEmlGetMem(uint8_t *data, int blockNum, int blocksCount) { int mfEmlSetMem(uint8_t *data, int blockNum, int blocksCount) { UsbCommand c = {CMD_MIFARE_EML_MEMSET, {blockNum, blocksCount, 0}}; - memcpy(c.d.asBytes, data, blocksCount * 16); + memcpy(c.d.asBytes, data, blocksCount * 16); SendCommand(&c); return 0; } @@ -416,7 +447,7 @@ int mfCGetBlock(uint8_t blockNo, uint8_t *data, uint8_t params) { UsbCommand c = {CMD_MIFARE_CGETBLOCK, {params, 0, blockNo}}; SendCommand(&c); - UsbCommand resp; + UsbCommand resp; if (WaitForResponseTimeout(CMD_ACK,&resp,1500)) { isOK = resp.arg[0] & 0xff; memcpy(data, resp.d.asBytes, 16); @@ -432,29 +463,54 @@ int mfCSetBlock(uint8_t blockNo, uint8_t *data, uint8_t *uid, bool wantWipe, uin uint8_t isOK = 0; UsbCommand c = {CMD_MIFARE_CSETBLOCK, {wantWipe, params & (0xFE | (uid == NULL ? 0:1)), blockNo}}; - memcpy(c.d.asBytes, data, 16); + memcpy(c.d.asBytes, data, 16); SendCommand(&c); - UsbCommand resp; - if (WaitForResponseTimeout(CMD_ACK,&resp,1500)) { + UsbCommand resp; + if (WaitForResponseTimeout(CMD_ACK, &resp, 1500)) { isOK = resp.arg[0] & 0xff; - if (uid != NULL) + if (uid != NULL) memcpy(uid, resp.d.asBytes, 4); - if (!isOK) + if (!isOK) return 2; } else { PrintAndLog("Command execute timeout"); return 1; } + return 0; } -int mfCSetUID(uint8_t *uid, uint8_t *atqa, uint8_t *sak, uint8_t *oldUID, bool wantWipe) { +int mfCWipe(uint32_t numSectors, bool gen1b, bool wantWipe, bool wantFill) { + uint8_t isOK = 0; + uint8_t cmdParams = wantWipe + wantFill * 0x02 + gen1b * 0x04; + UsbCommand c = {CMD_MIFARE_CWIPE, {numSectors, cmdParams, 0}}; + SendCommand(&c); + + UsbCommand resp; + WaitForResponse(CMD_ACK,&resp); + isOK = resp.arg[0] & 0xff; + + return isOK; +} + +int mfCSetUID(uint8_t *uid, uint8_t *atqa, uint8_t *sak, uint8_t *oldUID) { uint8_t oldblock0[16] = {0x00}; uint8_t block0[16] = {0x00}; + int gen = 0, res; + + gen = mfCIdentify(); - int old = mfCGetBlock(0, oldblock0, CSETBLOCK_SINGLE_OPER); - if (old == 0) { + /* generation 1a magic card by default */ + uint8_t cmdParams = CSETBLOCK_SINGLE_OPER; + if (gen == 2) { + /* generation 1b magic card */ + cmdParams = CSETBLOCK_SINGLE_OPER | CSETBLOCK_MAGIC_1B; + } + + res = mfCGetBlock(0, oldblock0, cmdParams); + + if (res == 0) { memcpy(block0, oldblock0, 16); PrintAndLog("old block 0: %s", sprint_hex(block0,16)); } else { @@ -463,20 +519,44 @@ int mfCSetUID(uint8_t *uid, uint8_t *atqa, uint8_t *sak, uint8_t *oldUID, bool w // fill in the new values // UID - memcpy(block0, uid, 4); + memcpy(block0, uid, 4); // Mifare UID BCC - block0[4] = block0[0]^block0[1]^block0[2]^block0[3]; + block0[4] = block0[0] ^ block0[1] ^ block0[2] ^ block0[3]; // mifare classic SAK(byte 5) and ATQA(byte 6 and 7, reversed) - if (sak!=NULL) - block0[5]=sak[0]; - if (atqa!=NULL) { - block0[6]=atqa[1]; - block0[7]=atqa[0]; - } - PrintAndLog("new block 0: %s", sprint_hex(block0,16)); - return mfCSetBlock(0, block0, oldUID, wantWipe, CSETBLOCK_SINGLE_OPER); + if (sak != NULL) + block0[5] = sak[0]; + if (atqa != NULL) { + block0[6] = atqa[1]; + block0[7] = atqa[0]; + } + PrintAndLog("new block 0: %s", sprint_hex(block0, 16)); + + res = mfCSetBlock(0, block0, oldUID, false, cmdParams); + if (res) { + PrintAndLog("Can't set block 0. Error: %d", res); + return res; + } + + return 0; } +int mfCIdentify() { + UsbCommand c = {CMD_MIFARE_CIDENT, {0, 0, 0}}; + SendCommand(&c); + UsbCommand resp; + WaitForResponse(CMD_ACK,&resp); + + uint8_t isGeneration = resp.arg[0] & 0xff; + switch( isGeneration ){ + case 1: PrintAndLog("Chinese magic backdoor commands (GEN 1a) detected"); break; + case 2: PrintAndLog("Chinese magic backdoor command (GEN 1b) detected"); break; + default: PrintAndLog("No chinese magic backdoor command detected"); break; + } + + return (int) isGeneration; +} + + // SNIFFER // constants @@ -508,7 +588,7 @@ int isTraceCardEmpty(void) { } int isBlockEmpty(int blockN) { - for (int i = 0; i < 16; i++) + for (int i = 0; i < 16; i++) if (traceCard[blockN * 16 + i] != 0) return 0; return 1; @@ -520,16 +600,17 @@ int isBlockTrailer(int blockN) { int saveTraceCard(void) { FILE * f; - + if ((!strlen(traceFileName)) || (isTraceCardEmpty())) return 0; - + f = fopen(traceFileName, "w+"); if ( !f ) return 1; - + for (int i = 0; i < 64; i++) { // blocks for (int j = 0; j < 16; j++) // bytes - fprintf(f, "%02x", *(traceCard + i * 16 + j)); - fprintf(f,"\n"); + fprintf(f, "%02x", *(traceCard + i * 16 + j)); + if (i < 63) + fprintf(f,"\n"); } fclose(f); return 0; @@ -540,10 +621,10 @@ int loadTraceCard(uint8_t *tuid) { char buf[64] = {0x00}; uint8_t buf8[64] = {0x00}; int i, blockNum; - - if (!isTraceCardEmpty()) + + if (!isTraceCardEmpty()) saveTraceCard(); - + memset(traceCard, 0x00, 4096); memcpy(traceCard, tuid + 3, 4); @@ -551,11 +632,11 @@ int loadTraceCard(uint8_t *tuid) { f = fopen(traceFileName, "r"); if (!f) return 1; - + blockNum = 0; - + while(!feof(f)){ - + memset(buf, 0, sizeof(buf)); if (fgets(buf, sizeof(buf), f) == NULL) { PrintAndLog("File reading error."); @@ -583,20 +664,20 @@ int loadTraceCard(uint8_t *tuid) { int mfTraceInit(uint8_t *tuid, uint8_t *atqa, uint8_t sak, bool wantSaveToEmlFile) { - if (traceCrypto1) + if (traceCrypto1) crypto1_destroy(traceCrypto1); traceCrypto1 = NULL; - if (wantSaveToEmlFile) + if (wantSaveToEmlFile) loadTraceCard(tuid); - + traceCard[4] = traceCard[0] ^ traceCard[1] ^ traceCard[2] ^ traceCard[3]; traceCard[5] = sak; memcpy(&traceCard[6], atqa, 2); traceCurBlock = 0; uid = bytes_to_num(tuid + 3, 4); - + traceState = TRACE_IDLE; return 0; @@ -605,7 +686,7 @@ int mfTraceInit(uint8_t *tuid, uint8_t *atqa, uint8_t sak, bool wantSaveToEmlFil void mf_crypto1_decrypt(struct Crypto1State *pcs, uint8_t *data, int len, bool isEncrypted){ uint8_t bt = 0; int i; - + if (len != 1) { for (i = 0; i < len; i++) data[i] = crypto1_byte(pcs, 0x00, isEncrypted) ^ data[i]; @@ -613,7 +694,7 @@ void mf_crypto1_decrypt(struct Crypto1State *pcs, uint8_t *data, int len, bool i bt = 0; for (i = 0; i < 4; i++) bt |= (crypto1_bit(pcs, 0, isEncrypted) ^ BIT(data[0], i)) << i; - + data[0] = bt; } return; @@ -628,24 +709,24 @@ int mfTraceDecode(uint8_t *data_src, int len, bool wantSaveToEmlFile) { traceState = TRACE_ERROR; return 1; } - + memcpy(data, data_src, len); if ((traceCrypto1) && ((traceState == TRACE_IDLE) || (traceState > TRACE_AUTH_OK))) { mf_crypto1_decrypt(traceCrypto1, data, len, 0); PrintAndLog("dec> %s", sprint_hex(data, len)); - AddLogHex(logHexFileName, "dec> ", data, len); + AddLogHex(logHexFileName, "dec> ", data, len); } - + switch (traceState) { - case TRACE_IDLE: + case TRACE_IDLE: // check packet crc16! if ((len >= 4) && (!CheckCrc14443(CRC_14443_A, data, len))) { PrintAndLog("dec> CRC ERROR!!!"); - AddLogLine(logHexFileName, "dec> ", "CRC ERROR!!!"); + AddLogLine(logHexFileName, "dec> ", "CRC ERROR!!!"); traceState = TRACE_ERROR; // do not decrypt the next commands return 1; } - + // AUTHENTICATION if ((len ==4) && ((data[0] == 0x60) || (data[0] == 0x61))) { traceState = TRACE_AUTH1; @@ -673,11 +754,11 @@ int mfTraceDecode(uint8_t *data_src, int len, bool wantSaveToEmlFile) { traceState = TRACE_ERROR; // do not decrypt the next commands return 0; } - + return 0; break; - - case TRACE_READ_DATA: + + case TRACE_READ_DATA: if (len == 18) { traceState = TRACE_IDLE; @@ -694,7 +775,7 @@ int mfTraceDecode(uint8_t *data_src, int len, bool wantSaveToEmlFile) { } break; - case TRACE_WRITE_OK: + case TRACE_WRITE_OK: if ((len == 1) && (data[0] == 0x0a)) { traceState = TRACE_WRITE_DATA; @@ -705,7 +786,7 @@ int mfTraceDecode(uint8_t *data_src, int len, bool wantSaveToEmlFile) { } break; - case TRACE_WRITE_DATA: + case TRACE_WRITE_DATA: if (len == 18) { traceState = TRACE_IDLE; @@ -718,7 +799,7 @@ int mfTraceDecode(uint8_t *data_src, int len, bool wantSaveToEmlFile) { } break; - case TRACE_AUTH1: + case TRACE_AUTH1: if (len == 4) { traceState = TRACE_AUTH2; nt = bytes_to_num(data, 4); @@ -729,7 +810,7 @@ int mfTraceDecode(uint8_t *data_src, int len, bool wantSaveToEmlFile) { } break; - case TRACE_AUTH2: + case TRACE_AUTH2: if (len == 8) { traceState = TRACE_AUTH_OK; @@ -742,28 +823,38 @@ int mfTraceDecode(uint8_t *data_src, int len, bool wantSaveToEmlFile) { } break; - case TRACE_AUTH_OK: + case TRACE_AUTH_OK: if (len ==4) { traceState = TRACE_IDLE; - at_enc = bytes_to_num(data, 4); - - // decode key here) - ks2 = ar_enc ^ prng_successor(nt, 64); - ks3 = at_enc ^ prng_successor(nt, 96); - revstate = lfsr_recovery64(ks2, ks3); - lfsr_rollback_word(revstate, 0, 0); - lfsr_rollback_word(revstate, 0, 0); - lfsr_rollback_word(revstate, nr_enc, 1); - lfsr_rollback_word(revstate, uid ^ nt, 0); - - crypto1_get_lfsr(revstate, &lfsr); - printf("key> %x%x\n", (unsigned int)((lfsr & 0xFFFFFFFF00000000) >> 32), (unsigned int)(lfsr & 0xFFFFFFFF)); - AddLogUint64(logHexFileName, "key> ", lfsr); - + if (!traceCrypto1) { + at_enc = bytes_to_num(data, 4); + + // decode key here) + ks2 = ar_enc ^ prng_successor(nt, 64); + ks3 = at_enc ^ prng_successor(nt, 96); + revstate = lfsr_recovery64(ks2, ks3); + lfsr_rollback_word(revstate, 0, 0); + lfsr_rollback_word(revstate, 0, 0); + lfsr_rollback_word(revstate, nr_enc, 1); + lfsr_rollback_word(revstate, uid ^ nt, 0); + + crypto1_get_lfsr(revstate, &lfsr); + printf("key> %x%x\n", (unsigned int)((lfsr & 0xFFFFFFFF00000000) >> 32), (unsigned int)(lfsr & 0xFFFFFFFF)); + AddLogUint64(logHexFileName, "key> ", lfsr); + } else { + printf("key> nested not implemented!\n"); + at_enc = bytes_to_num(data, 4); + + crypto1_destroy(traceCrypto1); + + // not implemented + traceState = TRACE_ERROR; + } + int blockShift = ((traceCurBlock & 0xFC) + 3) * 16; if (isBlockEmpty((traceCurBlock & 0xFC) + 3)) memcpy(traceCard + blockShift + 6, trailerAccessBytes, 4); - + if (traceCurKey) { num_to_bytes(lfsr, 6, traceCard + blockShift + 10); } else { @@ -774,18 +865,9 @@ int mfTraceDecode(uint8_t *data_src, int len, bool wantSaveToEmlFile) { if (traceCrypto1) { crypto1_destroy(traceCrypto1); } - + // set cryptosystem state traceCrypto1 = lfsr_recovery64(ks2, ks3); - -// nt = crypto1_word(traceCrypto1, nt ^ uid, 1) ^ nt; - - /* traceCrypto1 = crypto1_create(lfsr); // key in lfsr - crypto1_word(traceCrypto1, nt ^ uid, 0); - crypto1_word(traceCrypto1, ar, 1); - crypto1_word(traceCrypto1, 0, 0); - crypto1_word(traceCrypto1, 0, 0);*/ - return 0; } else { traceState = TRACE_ERROR; @@ -793,7 +875,7 @@ int mfTraceDecode(uint8_t *data_src, int len, bool wantSaveToEmlFile) { } break; - default: + default: traceState = TRACE_ERROR; return 1; } @@ -801,6 +883,8 @@ int mfTraceDecode(uint8_t *data_src, int len, bool wantSaveToEmlFile) { return 0; } +// DECODING + int tryDecryptWord(uint32_t nt, uint32_t ar_enc, uint32_t at_enc, uint8_t *data, int len){ /* uint32_t nt; // tag challenge @@ -820,3 +904,73 @@ int tryDecryptWord(uint32_t nt, uint32_t ar_enc, uint32_t at_enc, uint8_t *data, crypto1_destroy(traceCrypto1); return 0; } + +/** validate_prng_nonce + * Determine if nonce is deterministic. ie: Suspectable to Darkside attack. + * returns + * true = weak prng + * false = hardend prng + */ +bool validate_prng_nonce(uint32_t nonce) { + uint16_t *dist = 0; + uint16_t x, i; + + dist = malloc(2 << 16); + if(!dist) + return -1; + + // init prng table: + for (x = i = 1; i; ++i) { + dist[(x & 0xff) << 8 | x >> 8] = i; + x = x >> 1 | (x ^ x >> 2 ^ x >> 3 ^ x >> 5) << 15; + } + + uint32_t res = (65535 - dist[nonce >> 16] + dist[nonce & 0xffff]) % 65535; + + free(dist); + return (res == 16); +} + +/* Detect Tag Prng, +* function performs a partial AUTH, where it tries to authenticate against block0, key A, but only collects tag nonce. +* the tag nonce is check to see if it has a predictable PRNG. +* @returns +* TRUE if tag uses WEAK prng (ie Now the NACK bug also needs to be present for Darkside attack) +* FALSE is tag uses HARDEND prng (ie hardnested attack possible, with known key) +*/ +int DetectClassicPrng(void){ + + UsbCommand resp, respA; + uint8_t cmd[] = {0x60, 0x00}; // MIFARE_AUTH_KEYA + uint32_t flags = ISO14A_CONNECT | ISO14A_RAW | ISO14A_APPEND_CRC | ISO14A_NO_RATS; + + UsbCommand c = {CMD_READER_ISO_14443a, {flags, sizeof(cmd), 0}}; + memcpy(c.d.asBytes, cmd, sizeof(cmd)); + + clearCommandBuffer(); + SendCommand(&c); + if (!WaitForResponseTimeout(CMD_ACK, &resp, 2000)) { + PrintAndLog("PRNG UID: Reply timeout."); + return -1; + } + + // if select tag failed. + if (resp.arg[0] == 0) { + PrintAndLog("PRNG error: selecting tag failed, can't detect prng."); + return -1; + } + + if (!WaitForResponseTimeout(CMD_ACK, &respA, 5000)) { + PrintAndLog("PRNG data: Reply timeout."); + return -1; + } + + // check respA + if (respA.arg[0] != 4) { + PrintAndLog("PRNG data error: Wrong length: %d", respA.arg[0]); + return -1; + } + + uint32_t nonce = bytes_to_num(respA.d.asBytes, respA.arg[0]); + return validate_prng_nonce(nonce); +}