always compile the rfid_hexdump() function, since DEBUG_LIBRFID might be defined...

[librfid] / src / rfid_layer2_iso14443a.c

diff --git a/src/rfid_layer2_iso14443a.c b/src/rfid_layer2_iso14443a.c
index 4716018..cdd6b23 100644 (file)
--- a/src/rfid_layer2_iso14443a.c
+++ b/src/rfid_layer2_iso14443a.c
@@ -16,13 +16,16 @@
  *
  *  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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
  */
 
 #include <stdlib.h>
 #include <unistd.h>
 #include <string.h>
 #include <errno.h>
+#ifdef  __MINGW32__
+#include <windows.h>
+#endif/*__MINGW32__*/
 
 #include <librfid/rfid.h>
 #include <librfid/rfid_layer2.h>
@@ -32,13 +35,15 @@
 
 #define TIMEOUT 1236
 
+unsigned long randctx[4]={0x22d4a017,0x773a1f44,0xc39e1460,0x9cde8801};
+
 /* Transceive a 7-bit short frame */
 int
 iso14443a_transceive_sf(struct rfid_layer2_handle *handle,
                         unsigned char cmd,
                         struct iso14443a_atqa *atqa)
 {
-       struct rfid_reader *rdr = handle->rh->reader;
+       const struct rfid_reader *rdr = handle->rh->reader;
 
        return rdr->iso14443a.transceive_sf(handle->rh, cmd, atqa);
 }
@@ -49,7 +54,7 @@ iso14443a_transceive_acf(struct rfid_layer2_handle *handle,
                         struct iso14443a_anticol_cmd *acf,
                         unsigned int *bit_of_col)
 {
-       struct rfid_reader *rdr = handle->rh->reader;
+       const struct rfid_reader *rdr = handle->rh->reader;
 
        return rdr->iso14443a.transceive_acf(handle->rh, acf, bit_of_col);
 }
@@ -80,20 +85,38 @@ iso14443a_code_nvb_bits(unsigned char *nvb, unsigned int bits)
        return 0;
 }
 
+int random_bit(void)
+{
+    unsigned long e;
+
+    e = randctx[0];    
+    randctx[0]=randctx[1];
+    randctx[1]=(randctx[2]<<19) + (randctx[2]>>13) + randctx[3];
+    randctx[2]=randctx[3] ^ randctx[0];
+    randctx[3]=e+randctx[1];
+    
+    return randctx[1]&1;
+}
+
 /* first bit is '1', second bit '2' */
 static void
-set_bit_in_field(unsigned char *bitfield, unsigned int bit)
+rnd_toggle_bit_in_field(unsigned char *bitfield, unsigned int size, unsigned int bit)
 {
-       unsigned int byte_count = bit / 8;
-       unsigned int bit_count = bit % 8;
-
-       DEBUGP("bitfield=%p, byte_count=%u, bit_count=%u\n",
-                       bitfield, byte_count, bit_count);
-       DEBUGP("%p = 0x%02x\n", (bitfield+byte_count), *(bitfield+byte_count));
-       *(bitfield+byte_count) |= 1 << (bit_count-1);
-       DEBUGP("%p = 0x%02x\n", (bitfield+byte_count), *(bitfield+byte_count));
+    unsigned int byte,rnd;
+
+    if(bit && (bit <= (size*8)) )
+    {
+       rnd=random_bit();
+       
+        DEBUGP("xor'ing bit %u with %u\n",bit,rnd);
+        bit--;
+        byte=bit/8;
+        bit=rnd<<(bit%8);
+        bitfield[byte] ^= bit;
+    }
 }
 
+
 static int
 iso14443a_anticol(struct rfid_layer2_handle *handle)
 {
@@ -122,7 +145,7 @@ iso14443a_anticol(struct rfid_layer2_handle *handle)
                return ret;
        }
        h->state = ISO14443A_STATE_ATQA_RCVD;
-
+       
        DEBUGP("ATQA: 0x%02x 0x%02x\n", *aqptr, *(aqptr+1));
 
        if (!atqa->bf_anticol) {
@@ -150,18 +173,20 @@ cascade:
        ret = iso14443a_transceive_acf(handle, &acf, &bit_of_col);
        if (ret < 0)
                return ret;
-       DEBUGP("bit_of_col = %u\n", bit_of_col);
        
        while (bit_of_col != ISO14443A_BITOFCOL_NONE) {
-               set_bit_in_field(&acf.uid_bits[0], bit_of_col-16);
+               DEBUGP("collision at pos %u\n", bit_of_col);
+
                iso14443a_code_nvb_bits(&acf.nvb, bit_of_col);
+               rnd_toggle_bit_in_field(acf.uid_bits, sizeof(acf.uid_bits), bit_of_col);
+               DEBUGP("acf: nvb=0x%02X uid_bits=%s\n",acf.nvb,rfid_hexdump(acf.uid_bits,sizeof(acf.uid_bits)));
                ret = iso14443a_transceive_acf(handle, &acf, &bit_of_col);
-               DEBUGP("bit_of_col = %u\n", bit_of_col);
                if (ret < 0)
                        return ret;
        }
 
        iso14443a_code_nvb_bits(&acf.nvb, 7*8);
+
        ret = iso14443a_transceive(handle, RFID_14443A_FRAME_REGULAR,
                                   (unsigned char *)&acf, 7, 
                                   (unsigned char *) &sak, &rx_len,
@@ -264,7 +289,7 @@ iso14443a_setopt(struct rfid_layer2_handle *handle, int optname,
                 const void *optval, unsigned int optlen)
 {
        int ret = -EINVAL;
-       struct rfid_reader *rdr = handle->rh->reader;
+       const struct rfid_reader *rdr = handle->rh->reader;
        unsigned int speed;
 
        switch (optname) {
@@ -325,7 +350,13 @@ iso14443a_init(struct rfid_reader_handle *rh)
                return NULL;
 
        memset(h, 0, sizeof(*h));
-
+       
+#ifdef  __MINGW32__
+       randctx[0] ^= GetTickCount();
+#endif/*__MINGW32__*/
+        for(ret=0;ret<23;ret++)
+            random_bit();
+       
        h->l2 = &rfid_layer2_iso14443a;
        h->rh = rh;
        h->priv.iso14443a.state = ISO14443A_STATE_NONE;