git.rot13.org Git - librfid/blob - rfid_layer2_iso14443a.c

   1 /* ISO 14443-3 A anticollision implementation
   2  *
   3  * (C) 2005 by Harald Welte <laforge@gnumonks.org>
   4  *
   5  */
   6
   7 /*
   8  *  This program is free software; you can redistribute it and/or modify
   9  *  it under the terms of the GNU General Public License version 2
  10  *  as published by the Free Software Foundation
  11  *
  12  *  This program is distributed in the hope that it will be useful,
  13  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  *  GNU General Public License for more details.
  16  *
  17  *  You should have received a copy of the GNU General Public License
  18  *  along with this program; if not, write to the Free Software
  19  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  20  */
  21
  22 #include <stdlib.h>
  23 #include <unistd.h>
  24 #include <string.h>
  25
  26 #include <rfid/rfid.h>
  27 #include <rfid/rfid_layer2.h>
  28 #include <rfid/rfid_reader.h>
  29 #include <rfid/rfid_layer2_iso14443a.h>
  30
  31 #define TIMEOUT 1236
  32
  33 /* Transcieve a 7-bit short frame */
  34 static int
  35 iso14443a_transcieve_sf(struct rfid_layer2_handle *handle,
  36                          unsigned char cmd,
  37                          struct iso14443a_atqa *atqa)
  38 {
  39         struct rfid_reader *rdr = handle->rh->reader;
  40
  41         return rdr->iso14443a.transcieve_sf(handle->rh, cmd, atqa);
  42 }
  43
  44 /* Transmit an anticollission bit frame */
  45 static int
  46 iso14443a_transcieve_acf(struct rfid_layer2_handle *handle,
  47                          struct iso14443a_anticol_cmd *acf,
  48                          unsigned int *bit_of_col)
  49 {
  50         struct rfid_reader *rdr = handle->rh->reader;
  51
  52         return rdr->iso14443a.transcieve_acf(handle->rh, acf, bit_of_col);
  53 }
  54
  55 /* Transmit a regular frame */
  56 static int
  57 iso14443a_transcieve(struct rfid_layer2_handle *handle,
  58                         const unsigned char *tx_buf, unsigned int tx_len,
  59                         unsigned char *rx_buf, unsigned int *rx_len,
  60                         unsigned int timeout, unsigned int flags)
  61 {
  62         return handle->rh->reader->transcieve(handle->rh, tx_buf, tx_len,
  63                                                 rx_buf, rx_len, timeout, flags);
  64 }
  65
  66 static int
  67 iso14443a_code_nvb_bits(unsigned char *nvb, unsigned int bits)
  68 {
  69         unsigned int byte_count = bits / 8;
  70         unsigned int bit_count = bits % 8;
  71
  72         if (byte_count < 2 || byte_count > 7)
  73                 return -1;
  74
  75         *nvb = ((byte_count & 0xf) << 4) | bit_count;
  76
  77         return 0;
  78 }
  79
  80 /* first bit is '1', second bit '2' */
  81 static void
  82 set_bit_in_field(unsigned char *bitfield, unsigned int bit)
  83 {
  84         unsigned int byte_count = bit / 8;
  85         unsigned int bit_count = bit % 8;
  86
  87         DEBUGP("bitfield=%p, byte_count=%u, bit_count=%u\n",
  88                         bitfield, byte_count, bit_count);
  89         DEBUGP("%p = 0x%02x\n", (bitfield+byte_count), *(bitfield+byte_count));
  90         *(bitfield+byte_count) |= 1 << (bit_count-1);
  91         DEBUGP("%p = 0x%02x\n", (bitfield+byte_count), *(bitfield+byte_count));
  92 }
  93
  94 static int
  95 iso14443a_anticol(struct rfid_layer2_handle *handle)
  96 {
  97         int ret;
  98         unsigned int uid_size;
  99         struct iso14443a_atqa atqa;
 100         struct iso14443a_anticol_cmd acf;
 101         unsigned int bit_of_col;
 102         unsigned char sak[3];
 103         unsigned char uid[10];  // triple size equals 10 bytes;
 104         unsigned int rx_len = sizeof(sak);
 105         char *aqptr = (char *) &atqa;
 106
 107         memset(uid, 0, sizeof(uid));
 108         memset(sak, 0, sizeof(sak));
 109         memset(&atqa, 0, sizeof(atqa));
 110         memset(&acf, 0, sizeof(acf));
 111
 112         ret = iso14443a_transcieve_sf(handle, ISO14443A_SF_CMD_REQA, &atqa);
 113         if (ret < 0) {
 114                 handle->priv.iso14443a.state = ISO14443A_STATE_REQA_SENT;
 115                 DEBUGP("error during transcieve_sf: %d\n", ret);
 116                 return ret;
 117         }
 118         handle->priv.iso14443a.state = ISO14443A_STATE_ATQA_RCVD;
 119
 120         DEBUGP("ATQA: 0x%02x 0x%02x\n", *aqptr, *(aqptr+1));
 121
 122         if (!atqa.bf_anticol) {
 123                 handle->priv.iso14443a.state =ISO14443A_STATE_NO_BITFRAME_ANTICOL;
 124                 DEBUGP("no bitframe anticollission bits set, aborting\n");
 125                 return -1;
 126         }
 127
 128         if (atqa.uid_size == 2 || atqa.uid_size == 3)
 129                 uid_size = 3;
 130         else if (atqa.uid_size == 1)
 131                 uid_size = 2;
 132         else
 133                 uid_size = 1;
 134
 135         acf.sel_code = ISO14443A_AC_SEL_CODE_CL1;
 136
 137         handle->priv.iso14443a.state = ISO14443A_STATE_ANTICOL_RUNNING;
 138         handle->priv.iso14443a.level = ISO14443A_LEVEL_CL1;
 139
 140 cascade:
 141         iso14443a_code_nvb_bits(&acf.nvb, 16);
 142
 143         ret = iso14443a_transcieve_acf(handle, &acf, &bit_of_col);
 144         if (ret < 0)
 145                 return ret;
 146         DEBUGP("bit_of_col = %u\n", bit_of_col);
 147
 148         while (bit_of_col != ISO14443A_BITOFCOL_NONE) {
 149                 set_bit_in_field(&acf.uid_bits[0], bit_of_col-16);
 150                 iso14443a_code_nvb_bits(&acf.nvb, bit_of_col);
 151                 ret = iso14443a_transcieve_acf(handle, &acf, &bit_of_col);
 152                 DEBUGP("bit_of_col = %u\n", bit_of_col);
 153                 if (ret < 0)
 154                         return ret;
 155         }
 156
 157         iso14443a_code_nvb_bits(&acf.nvb, 7*8);
 158         ret = iso14443a_transcieve(handle, (unsigned char *)&acf, 7,
 159                                    (unsigned char *) &sak, &rx_len,
 160                                    TIMEOUT, 0);
 161         if (ret < 0)
 162                 return ret;
 163
 164         if (sak[0] & 0x04) {
 165                 /* Cascade bit set, UID not complete */
 166                 switch (acf.sel_code) {
 167                 case ISO14443A_AC_SEL_CODE_CL1:
 168                         /* cascading from CL1 to CL2 */
 169                         if (acf.uid_bits[0] != 0x88) {
 170                                 DEBUGP("Cascade bit set, but UID0 != 0x88\n");
 171                                 return -1;
 172                         }
 173                         memcpy(&uid[0], &acf.uid_bits[1], 3);
 174                         acf.sel_code = ISO14443A_AC_SEL_CODE_CL2;
 175                         handle->priv.iso14443a.level = ISO14443A_LEVEL_CL2;
 176                         break;
 177                 case ISO14443A_AC_SEL_CODE_CL2:
 178                         /* cascading from CL2 to CL3 */
 179                         memcpy(&uid[3], &acf.uid_bits[1], 3);
 180                         acf.sel_code = ISO14443A_AC_SEL_CODE_CL3;
 181                         handle->priv.iso14443a.level = ISO14443A_LEVEL_CL3;
 182                         break;
 183                 default:
 184                         DEBUGP("cannot cascade any further than CL3\n");
 185                         handle->priv.iso14443a.state = ISO14443A_STATE_ERROR;
 186                         return -1;
 187                         break;
 188                 }
 189                 goto cascade;
 190
 191         } else {
 192                 switch (acf.sel_code) {
 193                 case ISO14443A_AC_SEL_CODE_CL1:
 194                         /* single size UID (4 bytes) */
 195                         memcpy(&uid[0], &acf.uid_bits[0], 4);
 196                         break;
 197                 case ISO14443A_AC_SEL_CODE_CL2:
 198                         /* double size UID (7 bytes) */
 199                         memcpy(&uid[3], &acf.uid_bits[0], 4);
 200                         break;
 201                 case ISO14443A_AC_SEL_CODE_CL3:
 202                         /* triple size UID (10 bytes) */
 203                         memcpy(&uid[6], &acf.uid_bits[0], 4);
 204                         break;
 205                 }
 206         }
 207
 208         handle->priv.iso14443a.level = ISO14443A_LEVEL_NONE;
 209         handle->priv.iso14443a.state = ISO14443A_STATE_SELECTED;
 210
 211         {
 212                 int uid_len;
 213                 if (uid_size == 1)
 214                         uid_len = 4;
 215                 else if (uid_size == 2)
 216                         uid_len = 7;
 217                 else
 218                         uid_len = 10;
 219
 220                 DEBUGP("UID %s\n", rfid_hexdump(uid, uid_len));
 221         }
 222
 223         if (sak[0] & 0x20) {
 224                 DEBUGP("we have a T=CL compliant PICC\n");
 225                 handle->priv.iso14443a.tcl_capable = 1;
 226         } else {
 227                 DEBUGP("we have a T!=CL PICC\n");
 228                 handle->priv.iso14443a.tcl_capable = 0;
 229         }
 230
 231         return 0;
 232 }
 233
 234 static int
 235 iso14443a_hlta(struct rfid_layer2_handle *handle)
 236 {
 237         int ret;
 238         unsigned char tx_buf[2] = { 0x50, 0x00 };
 239         unsigned char rx_buf[10];
 240         unsigned int rx_len = sizeof(rx_buf);
 241
 242         ret = iso14443a_transcieve(handle, tx_buf, sizeof(tx_buf),
 243                                    rx_buf, &rx_len, 1000 /* 1ms */, 0);
 244         if (ret < 0) {
 245                 /* "error" case: we don't get somethng back from the card */
 246                 return 0;
 247         }
 248         return -1;
 249 }
 250
 251 static struct rfid_layer2_handle *
 252 iso14443a_init(struct rfid_reader_handle *rh)
 253 {
 254         int ret;
 255         struct rfid_layer2_handle *h = malloc(sizeof(*h));
 256         if (!h)
 257                 return NULL;
 258
 259         h->l2 = &rfid_layer2_iso14443a;
 260         h->rh = rh;
 261         h->priv.iso14443a.state = ISO14443A_STATE_NONE;
 262         h->priv.iso14443a.level = ISO14443A_LEVEL_NONE;
 263
 264         ret = h->rh->reader->iso14443a.init(h->rh);
 265         if (ret < 0) {
 266                 free(h);
 267                 return NULL;
 268         }
 269
 270         return h;
 271 }
 272
 273 static int
 274 iso14443a_fini(struct rfid_layer2_handle *handle)
 275 {
 276         free(handle);
 277         return 0;
 278 }
 279
 280
 281 struct rfid_layer2 rfid_layer2_iso14443a = {
 282         .id     = RFID_LAYER2_ISO14443A,
 283         .name   = "ISO 14443-3 A",
 284         .fn     = {
 285                 .init           = &iso14443a_init,
 286                 .open           = &iso14443a_anticol,
 287                 .transcieve     = &iso14443a_transcieve,
 288                 .close          = &iso14443a_hlta,
 289                 .fini           = &iso14443a_fini,
 290         },
 291 };
 292