Optional decryption of communication using keystream

tools/mfkey/example_trace.txt

@@ -13,3 +13,67 @@
 
 ./mfkey64 9c599b32 82a4166c a1e458ce 6eea41e0 5cadf439
 
+
+
+### Communication decryption
+
+
+RDR	26
+TAG	04 00
+RDR	93 20
+TAG	14 57 9f 69 b5
+RDR	93 70 14 57 9f 69 b5 2e 51
+TAG	08 b6 dd
+RDR	60 14 50 2d
+TAG	ce 84 42 61
+RDR	f8 04 9c cb 05 25 c8 4f
+TAG	94 31 cc 40
+RDR	70 93 df 99
+TAG	99 72 42 8c e2 e8 52 3f 45 6b 99 c8 31 e7 69 dc ed 09
+RDR	8c a6 82 7b
+TAG	ab 79 7f d3 69 e8 b9 3a 86 77 6b 40 da e3 ef 68 6e fd
+RDR	c3 c3 81 ba
+TAG	49 e2 c9 de f4 86 8d 17 77 67 0e 58 4c 27 23 02 86 f4
+RDR	fb dc d7 c1
+TAG	4a bd 96 4b 07 d3 56 3a a0 66 ed 0a 2e ac 7f 63 12 bf
+RDR	9f 91 49 ea
+
+
+./mfkey64 14579f69 ce844261 f8049ccb 0525c84f 9431cc40 7093df99 9972428ce2e8523f456b99c831e769dced09 8ca6827b ab797fd369e8b93a86776b40dae3ef686efd c3c381ba 49e2c9def4868d1777670e584c27230286f4 fbdcd7c1 4abd964b07d3563aa066ed0a2eac7f6312bf 9f9149ea
+
+Recovering key for:
+  uid: 14579f69
+   nt: ce844261
+ {nr}: f8049ccb
+ {ar}: 0525c84f
+ {at}: 9431cc40
+{enc0}: 7093df99
+{enc1}: 9972428ce2e8523f456b99c831e769dced09
+{enc2}: 8ca6827b
+{enc3}: ab797fd369e8b93a86776b40dae3ef686efd
+{enc4}: c3c381ba
+{enc5}: 49e2c9def4868d1777670e584c27230286f4
+{enc6}: fbdcd7c1
+{enc7}: 4abd964b07d3563aa066ed0a2eac7f6312bf
+{enc8}: 9f9149ea
+
+LFSR succesors of the tag challenge:
+  nt': 76d4468d
+ nt'': d5f3c476
+
+Keystream used to generate {ar} and {at}:
+  ks2: 73f18ec2
+  ks3: 41c20836
+
+Decrypted communication:
+{dec0}: 3014a7fe
+{dec1}: c26935cfdb95c4b4a27a84b8217ae9e48217
+{dec2}: 30152eef
+{dec3}: 493167c536c30f8e220b09675687067d4b31
+{dec4}: 3016b5dd
+{dec5}: 493167c536c30f8e220b09675687067d4b31
+{dec6}: 30173ccc
+{dec7}: 0000000000007e178869000000000000c4f2
+{dec8}: 61148834
+
+Found Key: [091e639cb715]

tools/mfkey/mfkey64.c

@@ -23,7 +23,7 @@ int main (int argc, char *argv[]) {
   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]);
+    printf(" syntax: %s <uid> <nt> <{nr}> <{ar}> <{at}> [enc] [enc...]\n\n", argv[0]);
     return 1;
   }
 
@@ -107,4 +107,4 @@ int main (int argc, char *argv[]) {
   crypto1_destroy(revstate);
 
   return 0;
-}
+}