+
+bool DecodeMifareData(uint8_t *cmd, uint8_t cmdsize, uint8_t *parity, bool isResponse, uint8_t *mfData, size_t *mfDataLen) {
+ static struct Crypto1State *traceCrypto1;
+ static uint64_t mfLastKey;
+
+ *mfDataLen = 0;
+
+ if (MifareAuthState == masAuthComplete) {
+ if (traceCrypto1) {
+ crypto1_destroy(traceCrypto1);
+ traceCrypto1 = NULL;
+ }
+
+ MifareAuthState = masFirstData;
+ return false;
+ }
+
+ if (cmdsize > 32)
+ return false;
+
+ if (MifareAuthState == masFirstData) {
+ if (AuthData.first_auth) {
+ AuthData.ks2 = AuthData.ar_enc ^ prng_successor(AuthData.nt, 64);
+ AuthData.ks3 = AuthData.at_enc ^ prng_successor(AuthData.nt, 96);
+
+ mfLastKey = GetCrypto1ProbableKey(&AuthData);
+ PrintAndLog(" | * | key | probable key:%012"PRIx64" Prng:%s ks2:%08x ks3:%08x | |",
+ mfLastKey,
+ validate_prng_nonce(AuthData.nt) ? "WEAK": "HARD",
+ AuthData.ks2,
+ AuthData.ks3);
+
+ AuthData.first_auth = false;
+
+ traceCrypto1 = lfsr_recovery64(AuthData.ks2, AuthData.ks3);
+ } else {
+ if (traceCrypto1) {
+ crypto1_destroy(traceCrypto1);
+ traceCrypto1 = NULL;
+ }
+
+ // check last used key
+ if (mfLastKey) {
+ if (NestedCheckKey(mfLastKey, &AuthData, cmd, cmdsize, parity)) {
+ PrintAndLog(" | * | key | last used key:%012"PRIx64" ks2:%08x ks3:%08x | |",
+ mfLastKey,
+ AuthData.ks2,
+ AuthData.ks3);
+
+ traceCrypto1 = lfsr_recovery64(AuthData.ks2, AuthData.ks3);
+ };
+ }
+
+ // check default keys
+ if (!traceCrypto1) {
+ for (int defaultKeyCounter = 0; defaultKeyCounter < MifareDefaultKeysSize; defaultKeyCounter++){
+ if (NestedCheckKey(MifareDefaultKeys[defaultKeyCounter], &AuthData, cmd, cmdsize, parity)) {
+ PrintAndLog(" | * | key | default key:%012"PRIx64" ks2:%08x ks3:%08x | |",
+ MifareDefaultKeys[defaultKeyCounter],
+ AuthData.ks2,
+ AuthData.ks3);
+
+ mfLastKey = MifareDefaultKeys[defaultKeyCounter];
+ traceCrypto1 = lfsr_recovery64(AuthData.ks2, AuthData.ks3);
+ break;
+ };
+ }
+ }
+
+ // nested
+ if (!traceCrypto1 && validate_prng_nonce(AuthData.nt)) {
+ uint32_t ntx = prng_successor(AuthData.nt, 90);
+ for (int i = 0; i < 16383; i++) {
+ ntx = prng_successor(ntx, 1);
+ if (NTParityChk(&AuthData, ntx)){
+
+ uint32_t ks2 = AuthData.ar_enc ^ prng_successor(ntx, 64);
+ uint32_t ks3 = AuthData.at_enc ^ prng_successor(ntx, 96);
+ struct Crypto1State *pcs = lfsr_recovery64(ks2, ks3);
+ memcpy(mfData, cmd, cmdsize);
+ mf_crypto1_decrypt(pcs, mfData, cmdsize, 0);
+
+ crypto1_destroy(pcs);
+ if (CheckCrypto1Parity(cmd, cmdsize, mfData, parity) && CheckCrc14443(CRC_14443_A, mfData, cmdsize)) {
+ AuthData.ks2 = ks2;
+ AuthData.ks3 = ks3;
+
+ AuthData.nt = ntx;
+ mfLastKey = GetCrypto1ProbableKey(&AuthData);
+ PrintAndLog(" | * | key | nested probable key:%012"PRIx64" ks2:%08x ks3:%08x | |",
+ mfLastKey,
+ AuthData.ks2,
+ AuthData.ks3);
+
+ traceCrypto1 = lfsr_recovery64(AuthData.ks2, AuthData.ks3);
+ break;
+ }
+ }
+ }
+ }
+
+ //hardnested
+ if (!traceCrypto1) {
+ printf("hardnested not implemented. uid:%x nt:%x ar_enc:%x at_enc:%x\n", AuthData.uid, AuthData.nt, AuthData.ar_enc, AuthData.at_enc);
+ MifareAuthState = masError;
+
+ /* TOO SLOW( needs to have more strong filter. with this filter - aprox 4 mln tests
+ uint32_t t = msclock();
+ uint32_t t1 = t;
+ int n = 0;
+ for (uint32_t i = 0; i < 0xFFFFFFFF; i++) {
+ if (NTParityChk(&AuthData, i)){
+
+ uint32_t ks2 = AuthData.ar_enc ^ prng_successor(i, 64);
+ uint32_t ks3 = AuthData.at_enc ^ prng_successor(i, 96);
+ struct Crypto1State *pcs = lfsr_recovery64(ks2, ks3);
+
+
+
+
+ n++;
+
+ if (!(n % 100000)) {
+ printf("delta=%d n=%d ks2=%x ks3=%x \n", msclock() - t1 , n, ks2, ks3);
+ t1 = msclock();
+ }
+
+ }
+ }
+ printf("delta=%d n=%d\n", msclock() - t, n);
+ */
+ }
+ }
+
+
+
+ MifareAuthState = masData;
+ }
+
+ if (MifareAuthState == masData && traceCrypto1) {
+ memcpy(mfData, cmd, cmdsize);
+ mf_crypto1_decrypt(traceCrypto1, mfData, cmdsize, 0);
+ *mfDataLen = cmdsize;
+ }
+
+ return *mfDataLen > 0;
+}
+
+bool NTParityChk(TAuthData *ad, uint32_t ntx) {
+ if (
+ (oddparity8(ntx >> 8 & 0xff) ^ (ntx & 0x01) ^ ((ad->nt_enc_par >> 5) & 0x01) ^ (ad->nt_enc & 0x01)) ||
+ (oddparity8(ntx >> 16 & 0xff) ^ (ntx >> 8 & 0x01) ^ ((ad->nt_enc_par >> 6) & 0x01) ^ (ad->nt_enc >> 8 & 0x01)) ||
+ (oddparity8(ntx >> 24 & 0xff) ^ (ntx >> 16 & 0x01) ^ ((ad->nt_enc_par >> 7) & 0x01) ^ (ad->nt_enc >> 16 & 0x01))
+ )
+ return false;
+
+ uint32_t ar = prng_successor(ntx, 64);
+ if (
+ (oddparity8(ar >> 8 & 0xff) ^ (ar & 0x01) ^ ((ad->ar_enc_par >> 5) & 0x01) ^ (ad->ar_enc & 0x01)) ||
+ (oddparity8(ar >> 16 & 0xff) ^ (ar >> 8 & 0x01) ^ ((ad->ar_enc_par >> 6) & 0x01) ^ (ad->ar_enc >> 8 & 0x01)) ||
+ (oddparity8(ar >> 24 & 0xff) ^ (ar >> 16 & 0x01) ^ ((ad->ar_enc_par >> 7) & 0x01) ^ (ad->ar_enc >> 16 & 0x01))
+ )
+ return false;
+
+ uint32_t at = prng_successor(ntx, 96);
+ if (
+ (oddparity8(ar & 0xff) ^ (at >> 24 & 0x01) ^ ((ad->ar_enc_par >> 4) & 0x01) ^ (ad->at_enc >> 24 & 0x01)) ||
+ (oddparity8(at >> 8 & 0xff) ^ (at & 0x01) ^ ((ad->at_enc_par >> 5) & 0x01) ^ (ad->at_enc & 0x01)) ||
+ (oddparity8(at >> 16 & 0xff) ^ (at >> 8 & 0x01) ^ ((ad->at_enc_par >> 6) & 0x01) ^ (ad->at_enc >> 8 & 0x01)) ||
+ (oddparity8(at >> 24 & 0xff) ^ (at >> 16 & 0x01) ^ ((ad->at_enc_par >> 7) & 0x01) ^ (ad->at_enc >> 16 & 0x01))
+ )
+ return false;
+
+ return true;
+}
+
+bool NestedCheckKey(uint64_t key, TAuthData *ad, uint8_t *cmd, uint8_t cmdsize, uint8_t *parity) {
+ uint8_t buf[32] = {0};
+ struct Crypto1State *pcs;
+
+ AuthData.ks2 = 0;
+ AuthData.ks3 = 0;
+
+ pcs = crypto1_create(key);
+ uint32_t nt1 = crypto1_word(pcs, ad->nt_enc ^ ad->uid, 1) ^ ad->nt_enc;
+ uint32_t ar = prng_successor(nt1, 64);
+ uint32_t at = prng_successor(nt1, 96);
+
+ crypto1_word(pcs, ad->nr_enc, 1);
+// uint32_t nr1 = crypto1_word(pcs, ad->nr_enc, 1) ^ ad->nr_enc; // if needs deciphered nr
+ uint32_t ar1 = crypto1_word(pcs, 0, 0) ^ ad->ar_enc;
+ uint32_t at1 = crypto1_word(pcs, 0, 0) ^ ad->at_enc;
+
+ if (!(ar == ar1 && at == at1 && NTParityChk(ad, nt1))) {
+ crypto1_destroy(pcs);
+ return false;
+ }
+
+ memcpy(buf, cmd, cmdsize);
+ mf_crypto1_decrypt(pcs, buf, cmdsize, 0);
+
+ crypto1_destroy(pcs);
+
+ if (!CheckCrypto1Parity(cmd, cmdsize, buf, parity))
+ return false;
+
+ if(!CheckCrc14443(CRC_14443_A, buf, cmdsize))
+ return false;
+
+ AuthData.nt = nt1;
+ AuthData.ks2 = AuthData.ar_enc ^ ar;
+ AuthData.ks3 = AuthData.at_enc ^ at;
+
+ return true;
+}
+
+bool CheckCrypto1Parity(uint8_t *cmd_enc, uint8_t cmdsize, uint8_t *cmd, uint8_t *parity_enc) {
+ for (int i = 0; i < cmdsize - 1; i++) {
+ if (oddparity8(cmd[i]) ^ (cmd[i + 1] & 0x01) ^ ((parity_enc[i / 8] >> (7 - i % 8)) & 0x01) ^ (cmd_enc[i + 1] & 0x01))
+ return false;
+ }
+
+ return true;
+}
+
+uint64_t GetCrypto1ProbableKey(TAuthData *ad) {
+ struct Crypto1State *revstate = lfsr_recovery64(ad->ks2, ad->ks3);
+ lfsr_rollback_word(revstate, 0, 0);
+ lfsr_rollback_word(revstate, 0, 0);
+ lfsr_rollback_word(revstate, ad->nr_enc, 1);
+ lfsr_rollback_word(revstate, ad->uid ^ ad->nt, 0);
+
+ uint64_t lfsr = 0;
+ crypto1_get_lfsr(revstate, &lfsr);
+ crypto1_destroy(revstate);
+
+ return lfsr;
+}
projects / proxmark3-svn / blobdiff