\r
\r
// statistics on nonce distance\r
+ int16_t isOK = 0;\r
+ #define NESTED_MAX_TRIES 12\r
+ uint16_t unsuccessfull_tries = 0;\r
if (calibrate) { // for first call only. Otherwise reuse previous calibration\r
LED_B_ON();\r
WDT_HIT();\r
\r
for (rtr = 0; rtr < 17; rtr++) {\r
\r
+ // Test if the action was cancelled\r
+ if(BUTTON_PRESS()) {\r
+ isOK = -2;\r
+ break;\r
+ }\r
+\r
// prepare next select. No need to power down the card.\r
if(mifare_classic_halt(pcs, cuid)) {\r
if (MF_DBGLEVEL >= 1) Dbprintf("Nested: Halt error");\r
delta_time = auth2_time - auth1_time + 32; // allow some slack for proper timing\r
}\r
if (MF_DBGLEVEL >= 3) Dbprintf("Nested: calibrating... ntdist=%d", i);\r
+ } else {\r
+ unsuccessfull_tries++;\r
+ if (unsuccessfull_tries > NESTED_MAX_TRIES) { // card isn't vulnerable to nested attack (random numbers are not predictable)\r
+ isOK = -3;\r
+ }\r
}\r
}\r
- \r
- if (rtr <= 1) return;\r
\r
davg = (davg + (rtr - 1)/2) / (rtr - 1);\r
\r
- if (MF_DBGLEVEL >= 3) Dbprintf("min=%d max=%d avg=%d, delta_time=%d", dmin, dmax, davg, delta_time);\r
+ if (MF_DBGLEVEL >= 3) Dbprintf("rtr=%d isOK=%d min=%d max=%d avg=%d, delta_time=%d", rtr, isOK, dmin, dmax, davg, delta_time);\r
\r
dmin = davg - 2;\r
dmax = davg + 2;\r
LED_C_ON();\r
\r
// get crypted nonces for target sector\r
- for(i=0; i < 2; i++) { // look for exactly two different nonces\r
+ for(i=0; i < 2 && !isOK; i++) { // look for exactly two different nonces\r
\r
target_nt[i] = 0;\r
while(target_nt[i] == 0) { // continue until we have an unambiguous nonce\r
memcpy(buf+16, &target_ks[1], 4);\r
\r
LED_B_ON();\r
- cmd_send(CMD_ACK, 0, 2, targetBlockNo + (targetKeyType * 0x100), buf, sizeof(buf));\r
+ cmd_send(CMD_ACK, isOK, 0, targetBlockNo + (targetKeyType * 0x100), buf, sizeof(buf));\r
LED_B_OFF();\r
\r
if (MF_DBGLEVEL >= 3) DbpString("NESTED FINISHED");\r