source: trunk/src/ifd/apdu.c @ 656

/*
 * APDU handling
 *
 * Copyright (C) 2003, Olaf Kirch <okir@suse.de>
 */

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

/*
 * Check the APDU type and length
 */
static int __ifd_apdu_check(const void *sbuf, size_t len, ifd_iso_apdu_t * iso)
{
        unsigned char *data = (unsigned char *)sbuf;
        unsigned int b;

        memset(iso, 0, sizeof(*iso));
        if (len < 5) {
                iso->cse = IFD_APDU_CASE_1;
                return 0;
        }

        b = data[4];
        len -= 5;

        /* APDU + Le */
        if (len == 0) {
                iso->cse = IFD_APDU_CASE_2S;
                iso->le = b ? b : 256;
                return 0;
        }

        data += 5;
        if (b == 0)
                b = 256;

        iso->lc = b;
        iso->len = len;
        iso->data = data;

        /* APDU + Lc + data */
        if (len == b) {
                iso->cse = IFD_APDU_CASE_3S;
                return 0;
        }

        /* APDU + Lc + data + Le */
        if (len == b + 1) {
                iso->cse = IFD_APDU_CASE_4S;
                iso->le = data[b] ? data[b] : 256;
                iso->len--;
                return 0;
        }

        return -1;
}

int ifd_apdu_case(const void *buf, size_t len)
{
        ifd_iso_apdu_t iso;

        if (__ifd_apdu_check(buf, len, &iso) < 0)
                return -1;
        return iso.cse;
}

/*
 * Convert internal APDU type to an ISO-7816-4 APDU
 */
int ifd_iso_apdu_parse(const void *data, size_t len, ifd_iso_apdu_t * iso)
{
        unsigned char *p;

        if (len < 4)
                return -1;

        if (__ifd_apdu_check(data, len, iso) < 0)
                return -1;

        p = (unsigned char *)data;
        iso->cla = *p++;
        iso->ins = *p++;
        iso->p1 = *p++;
        iso->p2 = *p++;

        return 0;
}