root/trunk/src/libopensc/card-emv.c

/*
 * card-emv.c: Functions specified by the EMV standard
 *
 * Copyright (C) 2001, 2002  Juha YrjölÀ <juha.yrjola@iki.fi>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include "internal.h"
#include <string.h>

static struct sc_card_operations emv_ops;
static struct sc_card_driver emv_drv = {
        "EMV compatible cards",
        "emv",
        &emv_ops,
        NULL, 0, NULL
};

static int emv_finish(sc_card_t *card)
{
        return 0;
}

static int parse_atr(const u8 *atr, size_t atr_len, int *t0_out, int *tx1, int *tx2,
                     u8 *hist_bytes, int *hbcount)
{
        const u8 *p = atr;
        int len = atr_len;
        int nr_hist_bytes, tx, i;
        
        if (len < 2)
                return -1;
        p++;
        len--;
        *t0_out = *p;
        nr_hist_bytes = *p & 0x0F;
        tx = *p >> 4;
        p++;
        for (i = 0; i < 4; i++)
                tx1[i] = tx2[i] = -1;
        for (i = 0; i < 4; i++)
                if (tx & (1 << i)) {
                        if (len <= 0)
                                return -1;
                        tx1[i] = *p++;
                        len--;
                }
        if (tx1[3] != -1) {
                tx = tx1[3] >> 4;
                for (i = 0; i < 4; i++)
                        if (tx & (1 << i)) {
                                if (len <= 0)
                                        return -1;
                                tx2[i] = *p++;
                                len--;
                        }
        }
        /* FIXME: possibly check TD2 */
        if (hist_bytes == NULL || nr_hist_bytes == 0)
                return 0;
        if (len < nr_hist_bytes)
                return -1;
        memcpy(hist_bytes, p, nr_hist_bytes);
        *hbcount = nr_hist_bytes;
        
        return 0;
}

static int emv_match_card(sc_card_t *card)
{
        int i, r, hbcount = 0, match = 1;
        int tx1[4], tx2[4], t0;
        char line[200], *linep = line;
        u8 hist_bytes[32];

        r = parse_atr(card->atr, card->atr_len, &t0, tx1, tx2, hist_bytes, &hbcount);
        if (r)
                return 0;
        for (i = 0; i < 4; i++)
                if (tx1[i] != -1)
                        linep += sprintf(linep, "T%c1 = 0x%02X ", 'A' + i, tx1[i]);
        for (i = 0; i < 4; i++)
                if (tx2[i] != -1)
                        linep += sprintf(linep, "T%c2 = 0x%02X ", 'A' + i, tx2[i]);
        if (card->ctx->debug >= 4) {
                sc_debug(card->ctx, "ATR parse: %s\n", line);
                if (hbcount) {
                        sc_hex_dump(card->ctx, hist_bytes, hbcount, line, sizeof(line));
                        sc_debug(card->ctx, "historic bytes:\n%s", line);
                }
        }
        if ((t0 & 0xF0) != 0x60)
                match = 0;
        if (match && tx1[1] != 0x00)
                match = 0;
        if (match && tx1[2] == -1)
                match = 0;
        if (match)
                for (i = 0; i < 4; i++)
                        if (tx2[i] != -1)
                                match = 0;
        return match;
}

static int emv_init(sc_card_t *card)
{
        card->drv_data = NULL;
        card->cla = 0x00;

        return 0;
}

static int emv_select_file(sc_card_t *card, const sc_path_t *path,
                           sc_file_t **file)
{
        int r;
        struct sc_card_driver *iso_drv = sc_get_iso7816_driver();
        const struct sc_card_operations *ops = iso_drv->ops;

        r = ops->select_file(card, path, file);
        if (r)
                return r;
        if (file != NULL && path->len == 2 && memcmp(path->value, "\x3F\x00", 2) == 0)
                (*file)->type = SC_FILE_TYPE_DF;
        if (file != NULL && (*file)->namelen)
                (*file)->type = SC_FILE_TYPE_DF;
        return 0;
}

static struct sc_card_driver * sc_get_driver(void)
{
        struct sc_card_driver *iso_drv = sc_get_iso7816_driver();

        emv_ops = *iso_drv->ops;
        emv_ops.match_card = emv_match_card;
        emv_ops.init = emv_init;
        emv_ops.finish = emv_finish;
        emv_ops.select_file = emv_select_file;

        return &emv_drv;
}

#if 1
struct sc_card_driver * sc_get_emv_driver(void)
{
        return sc_get_driver();
}
#endif