bignum.c

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/*
 * Big number math
 * Copyright (c) 2006, Jouni Malinen <j@w1.fi>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * Alternatively, this software may be distributed under the terms of BSD
 * license.
 *
 * See README and COPYING for more details.
 */

#include "includes.h"

#include "common.h"
#include "bignum.h"

#ifdef CONFIG_INTERNAL_LIBTOMMATH
#include "libtommath.c"
#else /* CONFIG_INTERNAL_LIBTOMMATH */
#include <tommath.h>
#endif /* CONFIG_INTERNAL_LIBTOMMATH */


/*
 * The current version is just a wrapper for LibTomMath library, so
 * struct bignum is just typecast to mp_int.
 */

struct bignum * bignum_init(void)
{
        struct bignum *n = os_zalloc(sizeof(mp_int));
        if (n == NULL)
                return NULL;
        if (mp_init((mp_int *) n) != MP_OKAY) {
                os_free(n);
                n = NULL;
        }
        return n;
}


void bignum_deinit(struct bignum *n)
{
        if (n) {
                mp_clear((mp_int *) n);
                os_free(n);
        }
}


size_t bignum_get_unsigned_bin_len(struct bignum *n)
{
        return mp_unsigned_bin_size((mp_int *) n);
}


int bignum_get_unsigned_bin(const struct bignum *n, u8 *buf, size_t *len)
{
        size_t need = mp_unsigned_bin_size((mp_int *) n);
        if (len && need > *len) {
                *len = need;
                return -1;
        }
        if (mp_to_unsigned_bin((mp_int *) n, buf) != MP_OKAY) {
                wpa_printf(MSG_DEBUG, "BIGNUM: %s failed", __func__);
                return -1;
        }
        if (len)
                *len = need;
        return 0;
}


int bignum_set_unsigned_bin(struct bignum *n, const u8 *buf, size_t len)
{
        if (mp_read_unsigned_bin((mp_int *) n, (u8 *) buf, len) != MP_OKAY) {
                wpa_printf(MSG_DEBUG, "BIGNUM: %s failed", __func__);
                return -1;
        }
        return 0;
}


int bignum_cmp(const struct bignum *a, const struct bignum *b)
{
        return mp_cmp((mp_int *) a, (mp_int *) b);
}


int bignum_cmp_d(const struct bignum *a, unsigned long b)
{
        return mp_cmp_d((mp_int *) a, b);
}


int bignum_add(const struct bignum *a, const struct bignum *b,
               struct bignum *c)
{
        if (mp_add((mp_int *) a, (mp_int *) b, (mp_int *) c) != MP_OKAY) {
                wpa_printf(MSG_DEBUG, "BIGNUM: %s failed", __func__);
                return -1;
        }
        return 0;
}


int bignum_sub(const struct bignum *a, const struct bignum *b,
               struct bignum *c)
{
        if (mp_sub((mp_int *) a, (mp_int *) b, (mp_int *) c) != MP_OKAY) {
                wpa_printf(MSG_DEBUG, "BIGNUM: %s failed", __func__);
                return -1;
        }
        return 0;
}


int bignum_mul(const struct bignum *a, const struct bignum *b,
               struct bignum *c)
{
        if (mp_mul((mp_int *) a, (mp_int *) b, (mp_int *) c) != MP_OKAY) {
                wpa_printf(MSG_DEBUG, "BIGNUM: %s failed", __func__);
                return -1;
        }
        return 0;
}


int bignum_mulmod(const struct bignum *a, const struct bignum *b,
                  const struct bignum *c, struct bignum *d)
{
        if (mp_mulmod((mp_int *) a, (mp_int *) b, (mp_int *) c, (mp_int *) d)
            != MP_OKAY) {
                wpa_printf(MSG_DEBUG, "BIGNUM: %s failed", __func__);
                return -1;
        }
        return 0;
}


int bignum_exptmod(const struct bignum *a, const struct bignum *b,
                   const struct bignum *c, struct bignum *d)
{
        if (mp_exptmod((mp_int *) a, (mp_int *) b, (mp_int *) c, (mp_int *) d)
            != MP_OKAY) {
                wpa_printf(MSG_DEBUG, "BIGNUM: %s failed", __func__);
                return -1;
        }
        return 0;
}