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Merge pull request #609 from gelotus/fix-4k
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Fix 4k - [@gelotus]
(we can re-introduce support for other card types later as long as we adhere to the principal that we don't write unless requested to)
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@AdamLaurie
AdamLaurie committed Jul 4, 2020
2 parents fc51c86 + 6fb61d3 commit 66d3560
Showing 1 changed file with 26 additions and 122 deletions.
148 changes: 26 additions & 122 deletions utils/nfc-mfclassic.c
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Original file line number Diff line number Diff line change
Expand Up @@ -76,8 +76,7 @@ static bool bUseKeyFile;
static bool bForceKeyFile;
static bool bTolerateFailures;
static bool bFormatCard;
static bool magic2 = false;
static bool magic3 = false;
static bool dWrite = false;
static bool unlocked = false;
static uint8_t uiBlocks;
static uint8_t keys[] = {
Expand Down Expand Up @@ -217,15 +216,6 @@ authenticate(uint32_t uiBlock)
if (nfc_initiator_mifare_cmd(pnd, mc, uiBlock, &mp))
return true;

} else if (magic3) {
//If it's a One Time Write card, we're gonna authenticate with the default keys
memcpy(mp.mpa.abtKey, default_key, sizeof(default_key));


// Try to authenticate for the current sector
if (nfc_initiator_mifare_cmd(pnd, mc, uiBlock, &mp)) {
return true;
}
// If formatting or not using key file, try to guess the right key
} else if (bFormatCard || !bUseKeyFile) {
for (size_t key_index = 0; key_index < num_keys; key_index++) {
Expand Down Expand Up @@ -266,9 +256,9 @@ unlock_card(bool write)
// now send unlock
if (!transmit_bits(abtUnlock1, 7)) {
printf("Warning: Unlock command [1/2]: failed / not acknowledged.\n");
dWrite = true;
if (write) {
printf("Trying to rewrite block 0 on a gen2 tag.\n");
magic2 = true;
printf("Trying to rewrite block 0 on a direct write tag.\n");
}
} else {
if (transmit_bytes(abtUnlock2, 1)) {
Expand Down Expand Up @@ -342,16 +332,12 @@ read_card(bool read_unlocked)
uint32_t uiReadBlocks = 0;

if (read_unlocked) {
unlock_card(false);
//If the user is attempting an unlocked read, but has a direct-write type magic card, they don't
//need to use the R mode. We'll trigger a warning and let them proceed.
if (magic2 || magic3) {
printf("Note: This card does not require an unlocked read (R) \n");
if (dWrite) {
printf("Note: This card can't do an unlocked read (R) \n");
read_unlocked = 0;
} else {
//If User has requested an unlocked read, but we're unable to unlock the card, we'll error out.
if (!unlock_card(false)) {
return false;
}
}
}

Expand Down Expand Up @@ -381,18 +367,11 @@ read_card(bool read_unlocked)
if (read_unlocked) {
memcpy(mtDump.amb[iBlock].mbd.abtData, mp.mpd.abtData, sizeof(mtDump.amb[iBlock].mbd.abtData));
} else {
//If we're using a One Time Write ('Magic 3') Badge - we'll use default keys + ACL
if (magic3) {
memcpy(mtDump.amb[iBlock].mbt.abtKeyA, default_key, sizeof(default_key));
memcpy(mtDump.amb[iBlock].mbt.abtAccessBits, mp.mpt.abtAccessBits, sizeof(mtDump.amb[iBlock].mbt.abtAccessBits));
memcpy(mtDump.amb[iBlock].mbt.abtKeyB, default_key, sizeof(default_key));
} else {
// Copy the keys over from our key dump and store the retrieved access bits
memcpy(mtDump.amb[iBlock].mbt.abtKeyA, mtKeys.amb[iBlock].mbt.abtKeyA, sizeof(mtDump.amb[iBlock].mbt.abtKeyA));
memcpy(mtDump.amb[iBlock].mbt.abtAccessBits, mp.mpt.abtAccessBits, sizeof(mtDump.amb[iBlock].mbt.abtAccessBits));
memcpy(mtDump.amb[iBlock].mbt.abtKeyB, mtKeys.amb[iBlock].mbt.abtKeyB, sizeof(mtDump.amb[iBlock].mbt.abtKeyB));
// Copy the keys over from our key dump and store the retrieved access bits
memcpy(mtDump.amb[iBlock].mbt.abtKeyA, mtKeys.amb[iBlock].mbt.abtKeyA, sizeof(mtDump.amb[iBlock].mbt.abtKeyA));
memcpy(mtDump.amb[iBlock].mbt.abtAccessBits, mp.mpt.abtAccessBits, sizeof(mtDump.amb[iBlock].mbt.abtAccessBits));
memcpy(mtDump.amb[iBlock].mbt.abtKeyB, mtKeys.amb[iBlock].mbt.abtKeyB, sizeof(mtDump.amb[iBlock].mbt.abtKeyB));
}
}
} else {
printf("!\nfailed to read trailer block 0x%02x\n", iBlock);
bFailure = true;
Expand Down Expand Up @@ -430,11 +409,7 @@ write_card(bool write_block_zero)

//Determine if we have to unlock the card
if (write_block_zero) {
if (!magic2 && !magic3) {
if (!unlock_card(true)) {
return false;
}
}
unlock_card(true);
}

printf("Writing %d blocks |", uiBlocks + write_block_zero);
Expand All @@ -459,9 +434,9 @@ write_card(bool write_block_zero)

// Try to authenticate for the current sector
// If we are are writing to a chinese magic card, we've already unlocked
// If we're writing to a One Time Write card, we need to authenticate
// If we're writing to a direct write card, we need to authenticate
// If we're writing something else, we'll need to authenticate
if ((write_block_zero && (magic2 || magic3)) || !write_block_zero) {
if ((write_block_zero && dWrite) || !write_block_zero) {
if (!authenticate(uiBlock) && !bTolerateFailures) {
printf("!\nError: authentication failed for block %02x\n", uiBlock);
return false;
Expand Down Expand Up @@ -508,7 +483,7 @@ write_card(bool write_block_zero)
bFailure = true;
printf("Failure to write to data block %i\n", uiBlock);
}
if (uiBlock == 0 && (magic2 || magic3)) {
if (uiBlock == 0 && dWrite) {
if (nfc_initiator_init(pnd) < 0) {
nfc_perror(pnd, "nfc_initiator_init");
nfc_close(pnd);
Expand Down Expand Up @@ -553,12 +528,11 @@ print_usage(const char *pcProgramName)
#else
printf("%s f|r|R|w|W a|b u|U<01ab23cd> <dump.mfd> [<keys.mfd> [f]]\n", pcProgramName);
#endif
printf(" f|r|R|w|W - Perform format (f) or read from (r) or unlocked read from (R) or write to (w) or unlocked write to (W) card\n");
printf(" f|r|R|w|W - Perform format (f) or read from (r) or unlocked read from (R) or write to (w) or block 0 write to (W) card\n");
printf(" *** format will reset all keys to FFFFFFFFFFFF and all data to 00 and all ACLs to default\n");
printf(" *** unlocked read does not require authentication and will reveal A and B keys\n");
printf(" *** note that unlocked write will attempt to overwrite block 0 including UID\n");
printf(" *** unlocking only works with special Mifare 1K cards (Chinese clones)\n");
printf(" *** unlocking (W) also works for rewriting block 0 in gen2 clones\n");
printf(" *** note that block 0 write will attempt to overwrite block 0 including UID\n");
printf(" *** block 0 write only works with special Mifare cards (Chinese clones)\n");
printf(" a|A|b|B - Use A or B keys for action; Halt on errors (a|b) or tolerate errors (A|B)\n");
printf(" u|U - Use any (u) uid or supply a uid specifically as U01ab23cd.\n");
printf(" <dump.mfd> - MiFare Dump (MFD) used to write (card to MFD) or (MFD to card)\n");
Expand All @@ -582,57 +556,6 @@ print_usage(const char *pcProgramName)
}


static bool is_directwrite(bool test_write)
{
printf("Checking if Badge is DirectWrite...\n");

// Set default keys
memcpy(mtDump.amb[0].mbt.abtKeyA, default_key, sizeof(default_key));
memcpy(mtDump.amb[0].mbt.abtAccessBits, default_acl, sizeof(mp.mpt.abtAccessBits));
memcpy(mtDump.amb[0].mbt.abtKeyB, default_key, sizeof(default_key));

// Temporarly override bUseKeyFile
bool orig_bUseKeyFile = bUseKeyFile;
bUseKeyFile = false;
// Try to authenticate for the current sector
if (!authenticate(0)) {
printf("!\nError: authentication failed for block 0x00\n");
bUseKeyFile = orig_bUseKeyFile;
return false;
}
// restore bUseKeyFile
bUseKeyFile = orig_bUseKeyFile;

// Try to read block 0
uint8_t original_b0[16];
if (nfc_initiator_mifare_cmd(pnd, MC_READ, 0, &mp)) {
memcpy(original_b0, mp.mpd.abtData, sizeof(mp.mpd.abtData));
printf(" Original Block 0: ");
for (int i = 0; i < 16; i++) {
printf("%02x", original_b0[i]);
}
printf("\n");
printf(" Original UID: %02x%02x%02x%02x\n",
original_b0[0], original_b0[1], original_b0[2], original_b0[3]);
} else {
printf("!\nError: unable to read block 0x00\n");
return false;
}

if(!test_write)
return true;

printf(" Attempt to write Block 0 ...\n");
memcpy(mp.mpd.abtData, original_b0, sizeof(original_b0));
if (!nfc_initiator_mifare_cmd(pnd, MC_WRITE, 0, &mp)) {
printf("Failure to write to data block 0\n");
return false;
}
printf(" Block 0 written successfully\n");

return true;
}

int
main(int argc, const char *argv[])
{
Expand Down Expand Up @@ -841,37 +764,10 @@ main(int argc, const char *argv[])
// MIFARE Plus 2K
uiBlocks = 0x7f;
}
// Chinese magic emulation card, ATS=0978009102:dabc1910
if ((res == 9) && (abtRx[5] == 0xda) && (abtRx[6] == 0xbc)
&& (abtRx[7] == 0x19) && (abtRx[8] == 0x10)) {
magic2 = true;
}
} else
printf("RATS support: no\n");
printf("Guessing size: seems to be a %lu-byte card\n", (unsigned long)((uiBlocks + 1) * sizeof(mifare_classic_block)));

//If size is 4k check for direct-write card
if (uiBlocks == 0xff) {
if (is_directwrite(atAction == ACTION_WRITE)) {
printf("Card is DirectWrite\n");
magic3 = true;
} else {
printf("Card is not DirectWrite\n");
// reset after error
if (nfc_initiator_select_passive_target(pnd, nmMifare, nt.nti.nai.abtUid, nt.nti.nai.szUidLen, NULL) <= 0) {
ERR("tag was removed");
}
}
}

//Check to see if we have a One Time Write badge (magic3)
if (pbtUID[0] == 0xaa && pbtUID[1] == 0x55 &&
pbtUID[2] == 0xc3 && pbtUID[3] == 0x96) {
printf("Card appears to be a One Time Write Card..\n");
magic3 = true;
}


if (bUseKeyFile) {
FILE *pfKeys = fopen(argv[5], "rb");
if (pfKeys == NULL) {
Expand Down Expand Up @@ -926,9 +822,17 @@ main(int argc, const char *argv[])
}
printf("Done.\n");
fclose(pfDump);
} else {
nfc_close(pnd);
nfc_exit(context);
exit(EXIT_FAILURE);
}
} else if (atAction == ACTION_WRITE) {
write_card(unlock);
if (!write_card(unlock)) {
nfc_close(pnd);
nfc_exit(context);
exit(EXIT_FAILURE);
}
}

nfc_close(pnd);
Expand Down

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