#include <inttypes.h>
-#include "crapto1/crapto1.h"
+#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
+#include "crapto1/crapto1.h"
+#include "mfkey.h"
+#include "util_posix.h"
+
+// 32 bit recover key from 2 nonces
int main (int argc, char *argv[]) {
- struct Crypto1State *s,*t;
- uint64_t key; // recovered key
- uint32_t uid; // serial number
- uint32_t nt; // tag challenge
- uint32_t nr0_enc; // first encrypted reader challenge
- uint32_t ar0_enc; // first encrypted reader response
- uint32_t nr1_enc; // second encrypted reader challenge
- uint32_t ar1_enc; // second encrypted reader response
+
+ nonces_t data = {0};
uint32_t ks2; // keystream used to encrypt reader response
+ uint64_t key; // recovered key
- printf("MIFARE Classic key recovery - based 32 bits of keystream\n");
+ printf("MIFARE Classic key recovery - based on 32 bits of keystream\n");
printf("Recover key from two 32-bit reader authentication answers only!\n\n");
- if (argc < 7) {
- printf(" syntax: %s <uid> <nt> <{nr_0}> <{ar_0}> <{nr_1}> <{ar_1}>\n\n",argv[0]);
+ if (argc != 7 && argc != 8) {
+ printf(" syntax: %s <uid> <nt0> <{nr_0}> <{ar_0}> [<nt1>] <{nr_1}> <{ar_1}>\n", argv[0]);
+ printf(" (you may omit nt1 if it is equal to nt0)\n\n");
return 1;
}
- sscanf(argv[1],"%x",&uid);
- sscanf(argv[2],"%x",&nt);
- sscanf(argv[3],"%x",&nr0_enc);
- sscanf(argv[4],"%x",&ar0_enc);
- sscanf(argv[5],"%x",&nr1_enc);
- sscanf(argv[6],"%x",&ar1_enc);
+ bool moebius_attack = (argc == 8);
+
+ sscanf(argv[1],"%x",&data.cuid);
+ sscanf(argv[2],"%x",&data.nonce);
+ data.nonce2 = data.nonce;
+ sscanf(argv[3],"%x",&data.nr);
+ sscanf(argv[4],"%x",&data.ar);
+ if (moebius_attack) {
+ sscanf(argv[5],"%x",&data.nonce2);
+ sscanf(argv[6],"%x",&data.nr2);
+ sscanf(argv[7],"%x",&data.ar2);
+ } else {
+ sscanf(argv[5],"%x",&data.nr2);
+ sscanf(argv[6],"%x",&data.ar2);
+ }
printf("Recovering key for:\n");
- printf(" uid: %08x\n",uid);
- printf(" nt: %08x\n",nt);
- printf(" {nr_0}: %08x\n",nr0_enc);
- printf(" {ar_0}: %08x\n",ar0_enc);
- printf(" {nr_1}: %08x\n",nr1_enc);
- printf(" {ar_1}: %08x\n",ar1_enc);
+ printf(" uid: %08x\n",data.cuid);
+ printf(" nt0: %08x\n",data.nonce);
+ printf(" {nr_0}: %08x\n",data.nr);
+ printf(" {ar_0}: %08x\n",data.ar);
+ printf(" nt1: %08x\n",data.nonce2);
+ printf(" {nr_1}: %08x\n",data.nr2);
+ printf(" {ar_1}: %08x\n",data.ar2);
+ uint64_t start_time = msclock();
+
// 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));
+ printf(" nt': %08x\n",prng_successor(data.nonce, 64));
+ printf(" nt'': %08x\n",prng_successor(data.nonce, 96));
// Extract the keystream from the messages
printf("\nKeystream used to generate {ar} and {at}:\n");
- ks2 = ar0_enc ^ prng_successor(nt, 64);
+ ks2 = data.ar ^ prng_successor(data.nonce, 64);
printf(" ks2: %08x\n",ks2);
- s = lfsr_recovery32(ar0_enc ^ prng_successor(nt, 64), 0);
-
- for(t = s; t->odd | t->even; ++t) {
- lfsr_rollback_word(t, 0, 0);
- lfsr_rollback_word(t, nr0_enc, 1);
- lfsr_rollback_word(t, uid ^ nt, 0);
- crypto1_get_lfsr(t, &key);
- crypto1_word(t, uid ^ nt, 0);
- crypto1_word(t, nr1_enc, 1);
- if (ar1_enc == (crypto1_word(t, 0, 0) ^ prng_successor(nt, 64))) {
- printf("\nFound Key: [%012" PRIx64 "]\n\n",key);
- break;
- }
+ bool success;
+ if (moebius_attack) {
+ success = mfkey32_moebius(data, &key);
+ } else {
+ success = mfkey32(data, &key);
+ }
+
+ if (success) {
+ printf("Recovered key: %012" PRIx64 "\n", key);
+ } else {
+ printf("Couldn't recover key.\n");
}
- free(s);
- return 0;
+ printf("Time spent: %1.2f seconds\n", (float)(msclock() - start_time)/1000.0);
}