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nfc-anticol: Cascade based on SAK rather than CT, better for educational purpose

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This commit is contained in:
Philippe Teuwen 2010-10-25 13:48:01 +00:00
parent 56e37ec309
commit 1963bb65e4
1 changed files with 58 additions and 29 deletions
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87
examples/nfc-anticol.c
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@ -45,7 +45,7 @@
static byte_t abtRx[MAX_FRAME_LEN];
static size_t szRxBits;
static size_t szRx;
static byte_t abtUid[10];
static byte_t abtRawUid[12];
static byte_t abtAtqa[2];
static byte_t abtSak;
static size_t szCL = 1;//Always start with Cascade Level 1 (CL1)
@ -59,6 +59,7 @@ byte_t abtSelectAll[2] = { 0x93, 0x20 };
byte_t abtSelectTag[9] = { 0x93, 0x70, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
byte_t abtRats[4] = { 0xe0, 0x50, 0xbc, 0xa5 };
byte_t abtHalt[4] = { 0x50, 0x00, 0x57, 0xcd };
#define CASCADE_BIT 0x04
static bool
transmit_bits (const byte_t * pbtTx, const size_t szTxBits)
@ -194,61 +195,82 @@ main (int argc, char *argv[])
// Anti-collision
transmit_bytes (abtSelectAll, 2);
// Test if we are dealing with a 4 bytes uid(CL1)
if (abtRx[0] != 0x88) {
// Save the UID
memcpy (abtUid, abtRx, 4);
} else {
// Save the first 3 bytes of UID
memcpy (abtUid, abtRx+1, 3);
szCL = 2;//or more
// Check answer
if ((abtRx[0] ^ abtRx[1] ^ abtRx[2] ^ abtRx[3] ^ abtRx[4]) != 0) {
printf("WARNING: BCC check failed!\n");
}
// Save the UID CL1
memcpy (abtRawUid, abtRx, 4);
//Prepare and send CL1 Select-Command
memcpy (abtSelectTag + 2, abtRx, 5);
append_iso14443a_crc (abtSelectTag, 7);
transmit_bytes (abtSelectTag, 9);
abtSak = abtRx[0];
// Test if we are dealing with a CL2
if (abtSak & CASCADE_BIT) {
szCL = 2;//or more
// Check answer
if (abtRawUid[0] != 0x88) {
printf("WARNING: Cascade bit set but CT != 0x88!\n");
}
}
if(szCL == 2) {
// We have to do the anti-collision for cascade level 2
// Prepare CL2 commands
abtSelectAll[0] = 0x95;
abtSelectTag[0] = 0x95;
// Anti-collision
transmit_bytes (abtSelectAll, 2);
if(abtRx[0] != 0x88) {
// Save the second part of UID
memcpy (abtUid + 3, abtRx, 4);
} else {
memcpy (abtUid + 3, abtRx + 1, 3);
szCL = 3;
// Check answer
if ((abtRx[0] ^ abtRx[1] ^ abtRx[2] ^ abtRx[3] ^ abtRx[4]) != 0) {
printf("WARNING: BCC check failed!\n");
}
// Selection
// Save UID CL2
memcpy (abtRawUid + 4, abtRx, 4);
// Selection
abtSelectTag[0] = 0x95;
memcpy (abtSelectTag + 2, abtRx, 5);
append_iso14443a_crc (abtSelectTag, 7);
transmit_bytes (abtSelectTag, 9);
abtSak = abtRx[0];
// Test if we are dealing with a CL3
if (abtSak & CASCADE_BIT) {
szCL = 3;
// Check answer
if (abtRawUid[0] != 0x88) {
printf("WARNING: Cascade bit set but CT != 0x88!\n");
}
}
if ( szCL == 3) {
// Do last CL
// Save the last part of UID
memcpy (abtUid + 6, abtRx, 4);
// We have to do the anti-collision for cascade level 3
// Prepare and send CL3 AC-Command
abtSelectAll[0] = 0x97;
transmit_bytes (abtSelectAll, 2);
// Check answer
if ((abtRx[0] ^ abtRx[1] ^ abtRx[2] ^ abtRx[3] ^ abtRx[4]) != 0) {
printf("WARNING: BCC check failed!\n");
}
// Save UID CL3
memcpy (abtRawUid + 8, abtRx, 4);
// Prepare and send final Select-Command
abtSelectTag[0] = 0x97;
memcpy (abtSelectTag + 2, abtRx, 5);
append_iso14443a_crc (abtSelectTag, 7);
transmit_bytes (abtSelectTag, 9);
transmit_bytes (abtSelectTag, 9);
abtSak = abtRx[0];
}
}
@ -261,12 +283,19 @@ main (int argc, char *argv[])
transmit_bytes (abtHalt, 4);
printf ("\nFound tag with\n UID: ");
printf ("%02x%02x%02x%02x", abtUid[0], abtUid[1], abtUid[2], abtUid[3]);
if (szCL > 1) {
printf ("%02x%02x%02x", abtUid[4], abtUid[5], abtUid[6]);
if (szCL > 2) {
printf("%02x%02x%02x", abtUid[7], abtUid[8], abtUid[9]);
}
switch (szCL) {
case 1:
printf ("%02x%02x%02x%02x", abtRawUid[0], abtRawUid[1], abtRawUid[2], abtRawUid[3]);
break;
case 2:
printf ("%02x%02x%02x", abtRawUid[1], abtRawUid[2], abtRawUid[3]);
printf ("%02x%02x%02x%02x", abtRawUid[4], abtRawUid[5], abtRawUid[6], abtRawUid[7]);
break;
case 3:
printf ("%02x%02x%02x", abtRawUid[1], abtRawUid[2], abtRawUid[3]);
printf ("%02x%02x%02x", abtRawUid[5], abtRawUid[6], abtRawUid[7]);
printf ("%02x%02x%02x%02x", abtRawUid[8], abtRawUid[9], abtRawUid[10], abtRawUid[11]);
break;
}
printf("\n");
printf("ATQA: %02x%02x\n SAK: %02x\n", abtAtqa[1], abtAtqa[0], abtSak);