github/RRG-Proxmark3
1
0
Fork 0
mirror of https://github.com/RfidResearchGroup/proxmark3.git synced 2025-08-14 02:27:26 -07:00
Code Issues Projects Releases Packages Wiki Activity Actions

mf_nonce_brute: allow clear nt. Fix the weird example half working with a clear nt provided as encrypted nt...

Browse source
This commit is contained in:
Philippe Teuwen 2024-09-02 11:38:46 +02:00
commit cce2c8e7ee
2 changed files with 21 additions and 11 deletions
Download patch file Download diff file Expand all files Collapse all files

17
tools/mfc/card_reader/mf_nonce_brute.c
View file

@ -32,6 +32,7 @@ uint32_t nr_enc = 0; // encrypted reader challenge
uint32_t ar_enc = 0; // encrypted reader response
uint32_t at_enc = 0; // encrypted tag response
uint32_t cmd_enc = 0; // next encrypted command to sector
bool is_nt_encrypted = 1;
uint32_t nt_par_err = 0;
uint32_t ar_par_err = 0;
@ -54,6 +55,7 @@ typedef struct thread_key_args {
uint32_t nr_enc;
uint16_t enc_len;
uint8_t enc[ENC_LEN]; // next encrypted command + a full read/write
bool is_nt_encrypted;
} targs_key;
//------------------------------------------------------------------
@ -452,7 +454,7 @@ static void *check_default_keys(void *arguments) {
struct Crypto1State *pcs = crypto1_create(key);
// NESTED decrypt nt with help of new key
crypto1_word(pcs, args->nt_enc ^ args->uid, 1);
crypto1_word(pcs, args->nt_enc ^ args->uid, args->is_nt_encrypted);
crypto1_word(pcs, args->nr_enc, 1);
crypto1_word(pcs, 0, 0);
crypto1_word(pcs, 0, 0);
@ -606,7 +608,7 @@ static void *brute_key_thread(void *arguments) {
struct Crypto1State *pcs = crypto1_create(key);
// NESTED decrypt nt with help of new key
crypto1_word(pcs, args->nt_enc ^ args->uid, 1);
crypto1_word(pcs, args->nt_enc ^ args->uid, args->is_nt_encrypted);
crypto1_word(pcs, args->nr_enc, 1);
crypto1_word(pcs, 0, 0);
crypto1_word(pcs, 0, 0);
@ -646,6 +648,8 @@ static void *brute_key_thread(void *arguments) {
static int usage(void) {
printf("\n");
printf("syntax: mf_nonce_brute <uid> <{nt}> <nt_par_err> <{nr}> <{ar}> <ar_par_err> <{at}> <at_par_err> [<{next_command}>]\n\n");
printf("alternatively, you can provide a clear nt:\n");
printf("syntax: mf_nonce_brute <uid> <nt> clear <{nr}> <{ar}> <ar_par_err> <{at}> <at_par_err> [<{next_command}>]\n\n");
printf("how to convert trace data to needed input:\n");
printf(" {nt} in trace = 8c! 42 e6! 4e!\n");
printf(" => {nt} = 8c42e64e\n");
@ -673,7 +677,12 @@ int main(int argc, const char *argv[]) {
sscanf(argv[1], "%x", &uid);
sscanf(argv[2], "%x", &nt_enc);
sscanf(argv[3], "%x", &nt_par_err);
if (strncmp(argv[3], "clear", 5) == 0) {
nt_par_err = 0;
is_nt_encrypted = 0;
} else {
sscanf(argv[3], "%x", &nt_par_err);
}
sscanf(argv[4], "%x", &nr_enc);
sscanf(argv[5], "%x", &ar_enc);
sscanf(argv[6], "%x", &ar_par_err);
@ -734,6 +743,7 @@ int main(int argc, const char *argv[]) {
def->nt_enc = nt_enc;
def->nr_enc = nr_enc;
def->enc_len = enc_len;
def->is_nt_encrypted = is_nt_encrypted;
memcpy(def->enc, enc, enc_len);
pthread_create(&threads[0], NULL, check_default_keys, (void *)def);
pthread_join(threads[0], NULL);
@ -820,6 +830,7 @@ int main(int argc, const char *argv[]) {
b->nt_enc = nt_enc;
b->nr_enc = nr_enc;
b->enc_len = enc_len;
b->is_nt_encrypted = is_nt_encrypted;
memcpy(b->enc, enc, enc_len);
pthread_create(&threads[i], NULL, brute_key_thread, (void *)b);
}

15
tools/mfc/card_reader/mf_nonce_brute_examples.md
View file

@ -83,18 +83,17 @@ Example with parity (from this trace http://www.proxmark.org/forum/viewtopic.php
+ 64: 4 : TAG bf dd 01 be!
+ 987853: 4 : 56 98 49 d6! !crc
```
=>
=> Using the plaintext tagnonce `nt`=`82a4166c`
```
./mf_nonce_brute 9c599b32 82a4166c 0000 a1e458ce 6eea41e0 0101 5cadf439 1001 8e0e5db9
| | | | | | | | |
+UID +nt | +{nr} +{ar} | +{at} | +{next cmd}
+nt_par_err +at_par_err +at_par_err
./mf_nonce_brute 9c599b32 82a4166c clear a1e458ce 6eea41e0 0101 5cadf439 1001 8e0e5db9
| | | | | | | | |
+UID +nt | +{nr} +{ar} | +{at} | +{next cmd}
+ nt is clear +ar_par_err +at_par_err
```
These two taken from above use the plaintext tagnonce `nt`=`82a4166c`, they still find a possible key candidate.
Without a next command, it still finds a possible key candidate.
```
./mf_nonce_brute 9c599b32 82a4166c 0000 a1e458ce 6eea41e0 0101 5cadf439 1001
./mf_nonce_brute 9c599b32 82a4166c 0000 98d76b77 d6c6e870 0000 ca7e0b63 0111
./mf_nonce_brute 9c599b32 82a4166c clear a1e458ce 6eea41e0 0101 5cadf439 1001
```
This one uses the encrypted tagnonce `{nt}`=`5a920d85`, it finds a valid key.