int mifare_sendcmd_shortex(struct Crypto1State *pcs, uint8_t crypted, uint8_t cmd, uint8_t data, uint8_t *answer, uint8_t *answer_parity, uint32_t *timing)
{
uint8_t dcmd[4], ecmd[4];
uint16_t pos, res;
uint8_t par[1]; // 1 Byte parity is enough here
dcmd[0] = cmd;
dcmd[1] = data;
AppendCrc14443a(dcmd, 2);
memcpy(ecmd, dcmd, sizeof(dcmd));
if (crypted) {
par[0] = 0;
for (pos = 0; pos < 4; pos++)
{
ecmd[pos] = crypto1_byte(pcs, 0x00, 0) ^ dcmd[pos];
par[0] |= (((filter(pcs->odd) ^ oddparity(dcmd[pos])) & 0x01) << (7-pos));
}
ReaderTransmitPar(ecmd, sizeof(ecmd), par, timing);
} else {
ReaderTransmit(dcmd, sizeof(dcmd), timing);
}
int len = ReaderReceive(answer, par);
if (answer_parity) *answer_parity = par[0];
if (crypted == CRYPT_ALL) {
if (len == 1) {
res = 0;
for (pos = 0; pos < 4; pos++)
res |= (crypto1_bit(pcs, 0, 0) ^ BIT(answer[0], pos)) << pos;
answer[0] = res;
} else {
for (pos = 0; pos < len; pos++)
{
answer[pos] = crypto1_byte(pcs, 0x00, 0) ^ answer[pos];
}
}
}
return len;
}
void mf_crypto1_encrypt(struct Crypto1State *pcs, uint8_t *data, uint16_t len, uint8_t *par) {
uint8_t bt = 0;
int i;
par[0] = 0;
for (i = 0; i < len; i++) {
bt = data[i];
data[i] = crypto1_byte(pcs, 0x00, 0) ^ data[i];
if((i&0x0007) == 0) par[i>>3] = 0;
par[i>>3] |= (((filter(pcs->odd) ^ oddparity(bt)) & 0x01)<<(7-(i&0x0007)));
}
return;
}
// crypto1 helpers
void mf_crypto1_decrypt(struct Crypto1State *pcs, uint8_t *data, int len){
uint8_t bt = 0;
int i;
if (len != 1) {
for (i = 0; i < len; i++)
data[i] = crypto1_byte(pcs, 0x00, 0) ^ data[i];
} else {
bt = 0;
for (i = 0; i < 4; i++)
bt |= (crypto1_bit(pcs, 0, 0) ^ BIT(data[0], i)) << i;
data[0] = bt;
}
return;
}
int mifare_classic_writeblock(struct Crypto1State *pcs, uint32_t uid, uint8_t blockNo, uint8_t *blockData)
{
// variables
int len, i;
uint32_t pos;
uint8_t par[3] = {0}; // enough for 18 Bytes to send
byte_t res;
uint8_t d_block[18], d_block_enc[18];
uint8_t* receivedAnswer = get_bigbufptr_recvrespbuf();
uint8_t* receivedAnswerPar = receivedAnswer + MAX_FRAME_SIZE;
// command MIFARE_CLASSIC_WRITEBLOCK
len = mifare_sendcmd_short(pcs, 1, 0xA0, blockNo, receivedAnswer, receivedAnswerPar, NULL);
if ((len != 1) || (receivedAnswer[0] != 0x0A)) { // 0x0a - ACK
if (MF_DBGLEVEL >= 1) Dbprintf("Cmd Error: %02x", receivedAnswer[0]);
return 1;
}
memcpy(d_block, blockData, 16);
AppendCrc14443a(d_block, 16);
// crypto
for (pos = 0; pos < 18; pos++)
{
d_block_enc[pos] = crypto1_byte(pcs, 0x00, 0) ^ d_block[pos];
par[pos>>3] |= (((filter(pcs->odd) ^ oddparity(d_block[pos])) & 0x01) << (7 - (pos&0x0007)));
}
ReaderTransmitPar(d_block_enc, sizeof(d_block_enc), par, NULL);
// Receive the response
len = ReaderReceive(receivedAnswer, receivedAnswerPar);
res = 0;
for (i = 0; i < 4; i++)
res |= (crypto1_bit(pcs, 0, 0) ^ BIT(receivedAnswer[0], i)) << i;
if ((len != 1) || (res != 0x0A)) {
if (MF_DBGLEVEL >= 1) Dbprintf("Cmd send data2 Error: %02x", res);
return 2;
}
return 0;
}
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];
} else {
bt = 0;
bt |= (crypto1_bit(pcs, 0, isEncrypted) ^ BIT(data[0], 0)) << 0;
bt |= (crypto1_bit(pcs, 0, isEncrypted) ^ BIT(data[0], 1)) << 1;
bt |= (crypto1_bit(pcs, 0, isEncrypted) ^ BIT(data[0], 2)) << 2;
bt |= (crypto1_bit(pcs, 0, isEncrypted) ^ BIT(data[0], 3)) << 3;
data[0] = bt;
}
return;
}
int mifare_classic_authex(struct Crypto1State *pcs, uint32_t uid, uint8_t blockNo, uint8_t keyType, uint64_t ui64Key, uint8_t isNested, uint32_t *ntptr, uint32_t *timing)
{
// variables
int len;
uint32_t pos;
uint8_t tmp4[4];
uint8_t par[1] = {0};
byte_t nr[4];
uint32_t nt, ntpp; // Supplied tag nonce
uint8_t mf_nr_ar[] = { 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00 };
uint8_t *receivedAnswer = get_bigbufptr_recvrespbuf();
uint8_t *receivedAnswerPar = receivedAnswer + MAX_FRAME_SIZE;
// Transmit MIFARE_CLASSIC_AUTH
len = mifare_sendcmd_short(pcs, isNested, 0x60 + (keyType & 0x01), blockNo, receivedAnswer, receivedAnswerPar, timing);
if (MF_DBGLEVEL >= 4) Dbprintf("rand tag nonce len: %x", len);
if (len != 4) return 1;
// "random" reader nonce:
nr[0] = 0x55;
nr[1] = 0x41;
nr[2] = 0x49;
nr[3] = 0x92;
// Save the tag nonce (nt)
nt = bytes_to_num(receivedAnswer, 4);
// ----------------------------- crypto1 create
if (isNested)
crypto1_destroy(pcs);
// Init cipher with key
crypto1_create(pcs, ui64Key);
if (isNested == AUTH_NESTED) {
// decrypt nt with help of new key
nt = crypto1_word(pcs, nt ^ uid, 1) ^ nt;
} else {
// Load (plain) uid^nt into the cipher
crypto1_word(pcs, nt ^ uid, 0);
}
// some statistic
if (!ntptr && (MF_DBGLEVEL >= 3))
Dbprintf("auth uid: %08x nt: %08x", uid, nt);
// save Nt
if (ntptr)
*ntptr = nt;
// Generate (encrypted) nr+parity by loading it into the cipher (Nr)
par[0] = 0;
for (pos = 0; pos < 4; pos++)
{
mf_nr_ar[pos] = crypto1_byte(pcs, nr[pos], 0) ^ nr[pos];
par[0] |= (((filter(pcs->odd) ^ oddparity(nr[pos])) & 0x01) << (7-pos));
}
// Skip 32 bits in pseudo random generator
nt = prng_successor(nt,32);
// ar+parity
for (pos = 4; pos < 8; pos++)
{
nt = prng_successor(nt,8);
mf_nr_ar[pos] = crypto1_byte(pcs,0x00,0) ^ (nt & 0xff);
par[0] |= (((filter(pcs->odd) ^ oddparity(nt & 0xff)) & 0x01) << (7-pos));
}
// Transmit reader nonce and reader answer
ReaderTransmitPar(mf_nr_ar, sizeof(mf_nr_ar), par, NULL);
// Receive 4 byte tag answer
len = ReaderReceive(receivedAnswer, receivedAnswerPar);
if (!len)
{
if (MF_DBGLEVEL >= 1) Dbprintf("Authentication failed. Card timeout.");
return 2;
}
memcpy(tmp4, receivedAnswer, 4);
ntpp = prng_successor(nt, 32) ^ crypto1_word(pcs, 0,0);
if (ntpp != bytes_to_num(tmp4, 4)) {
if (MF_DBGLEVEL >= 1) Dbprintf("Authentication failed. Error card response.");
return 3;
}
return 0;
}
int main (int argc, char *argv[]) {
struct Crypto1State *revstate;
uint64_t key; // recovered key
uint32_t uid; // serial number
uint32_t nt; // tag challenge
uint32_t nr_enc; // encrypted reader challenge
uint32_t ar_enc; // encrypted reader response
uint32_t at_enc; // encrypted tag response
uint32_t ks2; // keystream used to encrypt reader response
uint32_t ks3; // keystream used to encrypt tag response
printf("MIFARE Classic key recovery - based 64 bits of keystream\n");
printf("Recover key from only one complete authentication!\n\n");
if (argc < 6 ) {
printf(" syntax: %s <uid> <nt> <{nr}> <{ar}> <{at}> [enc] [enc...]\n\n", argv[0]);
return 1;
}
int encc = argc - 6;
int enclen[encc];
uint8_t enc[encc][120];
sscanf(argv[1], "%x", &uid);
sscanf(argv[2], "%x", &nt);
sscanf(argv[3], "%x", &nr_enc);
sscanf(argv[4], "%x", &ar_enc);
sscanf(argv[5], "%x", &at_enc);
for (int i = 0; i < encc; i++) {
enclen[i] = strlen(argv[i + 6]) / 2;
for (int i2 = 0; i2 < enclen[i]; i2++) {
sscanf(argv[i+6] + i2*2,"%2x", (uint8_t*)&enc[i][i2]);
}
}
printf("Recovering key for:\n");
printf(" uid: %08x\n", uid);
printf(" nt: %08x\n", nt);
printf(" {nr}: %08x\n", nr_enc);
printf(" {ar}: %08x\n", ar_enc);
printf(" {at}: %08x\n", at_enc);
for (int i = 0; i < encc; i++) {
printf("{enc%d}: ", i);
for (int i2 = 0; i2 < enclen[i]; i2++) {
printf("%02x", enc[i][i2]);
}
printf("\n");
}
/*
uint32_t uid = 0x9c599b32;
uint32_t tag_challenge = 0x82a4166c;
uint32_t nr_enc = 0xa1e458ce;
uint32_t reader_response = 0x6eea41e0;
uint32_t tag_response = 0x5cadf439;
*/
// Generate lfsr succesors of the tag challenge
printf("\nLFSR succesors of the tag challenge:\n");
printf(" nt': %08x\n",prng_successor(nt, 64));
printf(" nt'': %08x\n",prng_successor(nt, 96));
// Extract the keystream from the messages
printf("\nKeystream used to generate {ar} and {at}:\n");
ks2 = ar_enc ^ prng_successor(nt, 64);
ks3 = at_enc ^ prng_successor(nt, 96);
printf(" ks2: %08x\n",ks2);
printf(" ks3: %08x\n",ks3);
revstate = lfsr_recovery64(ks2, ks3);
// Decrypting communication using keystream if presented
if (argc > 6 ) {
printf("\nDecrypted communication:\n");
uint8_t ks4;
int rollb = 0;
for (int i = 0; i < encc; i++) {
printf("{dec%d}: ", i);
for (int i2 = 0; i2 < enclen[i]; i2++) {
ks4 = crypto1_byte(revstate, 0, 0);
printf("%02x", ks4 ^ enc[i][i2]);
rollb += 1;
}
printf("\n");
}
for (int i = 0; i < rollb; i++) {
lfsr_rollback_byte(revstate, 0, 0);
}
}
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, &key);
printf("\nFound Key: [%012"llx"]\n\n",key);
crypto1_destroy(revstate);
return 0;
}
