X-Git-Url: http://git.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/blobdiff_plain/32cfae439e0e2270638617fa09bf1026b0cf0e50..93f57590455b1c57ff09119b1de407ccd1d7ed62:/tools/nonce2key/nonce2key.c

diff --git a/tools/nonce2key/nonce2key.c b/tools/nonce2key/nonce2key.c
new file mode 100644
index 00000000..afe1b7ef
--- /dev/null
+++ b/tools/nonce2key/nonce2key.c
@@ -0,0 +1,57 @@
+#include "crapto1.h"
+#include <inttypes.h>
+#include <stdio.h>
+typedef unsigned char byte_t;
+
+int main(const int argc, const char* argv[]) {
+  struct Crypto1State *state;
+  uint32_t pos, uid, nt, nr, rr, nr_diff, ks1, ks2;
+  byte_t bt, i, ks3x[8], par[8][8];
+  uint64_t key, key_recovered;
+  uint64_t par_info;
+  uint64_t ks_info;
+  nr = rr = 0;
+  
+  if (argc < 5) {
+    printf("\nsyntax: %s <uid> <nt> <par> <ks>\n\n",argv[0]);
+    return 1;
+  }
+  sscanf(argv[1],"%08x",&uid);
+  sscanf(argv[2],"%08x",&nt);
+  sscanf(argv[3],"%016llx",&par_info);
+  sscanf(argv[4],"%016llx",&ks_info);
+  
+  // Reset the last three significant bits of the reader nonce
+  nr &= 0xffffff1f;
+  
+  printf("\nuid(%08x) nt(%08x) par(%016llx) ks(%016llx)\n\n",uid,nt,par_info,ks_info);
+
+  for (pos=0; pos<8; pos++)
+  {
+    ks3x[7-pos] = (ks_info >> (pos*8)) & 0x0f;
+    bt = (par_info >> (pos*8)) & 0xff;
+    for (i=0; i<8; i++)
+    {
+      par[7-pos][i] = (bt >> i) & 0x01;
+    }
+  }
+
+  printf("|diff|{nr}    |ks3|ks3^5|parity         |\n");
+  printf("+----+--------+---+-----+---------------+\n");
+  for (i=0; i<8; i++)
+  {
+    nr_diff = nr | i << 5;
+    printf("| %02x |%08x|",i << 5, nr_diff);
+    printf(" %01x |  %01x  |",ks3x[i], ks3x[i]^5);
+    for (pos=0; pos<7; pos++) printf("%01x,",par[i][pos]);
+    printf("%01x|\n",par[i][7]);
+  }
+  
+  state = lfsr_common_prefix(nr,rr,ks3x,par);
+  lfsr_rollback_word(state,uid^nt,0);
+  crypto1_get_lfsr(state,&key_recovered);
+  printf("\nkey recovered: %012llx\n\n",key_recovered);
+  crypto1_destroy(state);
+  
+  return 0;
+}