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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.
*/
/**
* bignum_init - Allocate memory for bignum
* Returns: Pointer to allocated bignum or %NULL on failure
*/
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;
}
/**
* bignum_deinit - Free bignum
* @n: Bignum from bignum_init()
*/
void bignum_deinit(struct bignum *n)
{
if (n) {
mp_clear((mp_int *) n);
os_free(n);
}
}
/**
* bignum_get_unsigned_bin - Get length of bignum as an unsigned binary buffer
* @n: Bignum from bignum_init()
* Returns: Length of n if written to a binary buffer
*/
size_t bignum_get_unsigned_bin_len(struct bignum *n)
{
return mp_unsigned_bin_size((mp_int *) n);
}
/**
* bignum_get_unsigned_bin - Set binary buffer to unsigned bignum
* @n: Bignum from bignum_init()
* @buf: Buffer for the binary number
* @len: Length of the buffer, can be %NULL if buffer is known to be long
* enough. Set to used buffer length on success if not %NULL.
* Returns: 0 on success, -1 on failure
*/
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;
}
/**
* bignum_set_unsigned_bin - Set bignum based on unsigned binary buffer
* @a: Bignum from bignum_init(); to be set to the given value
* @buf: Buffer with unsigned binary value
* @len: Length of buf in octets
* Returns: 0 on success, -1 on failure
*/
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;
}
/**
* bignum_cmp - Signed comparison
* @a: Bignum from bignum_init()
* @b: Bignum from bignum_init()
* Returns: 0 on success, -1 on failure
*/
int bignum_cmp(const struct bignum *a, const struct bignum *b)
{
return mp_cmp((mp_int *) a, (mp_int *) b);
}
/**
* bignum_cmd_d - Compare bignum to standard integer
* @a: Bignum from bignum_init()
* @b: Small integer
* Returns: 0 on success, -1 on failure
*/
int bignum_cmp_d(const struct bignum *a, unsigned long b)
{
return mp_cmp_d((mp_int *) a, b);
}
/**
* bignum_add - c = a + b
* @a: Bignum from bignum_init()
* @b: Bignum from bignum_init()
* @c: Bignum from bignum_init(); used to store the result of a + b
* Returns: 0 on success, -1 on failure
*/
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;
}
/**
* bignum_sub - c = a - b
* @a: Bignum from bignum_init()
* @b: Bignum from bignum_init()
* @c: Bignum from bignum_init(); used to store the result of a - b
* Returns: 0 on success, -1 on failure
*/
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;
}
/**
* bignum_mul - c = a * b
* @a: Bignum from bignum_init()
* @b: Bignum from bignum_init()
* @c: Bignum from bignum_init(); used to store the result of a * b
* Returns: 0 on success, -1 on failure
*/
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;
}
/**
* bignum_mulmod - d = a * b (mod c)
* @a: Bignum from bignum_init()
* @b: Bignum from bignum_init()
* @c: Bignum from bignum_init(); modulus
* @d: Bignum from bignum_init(); used to store the result of a * b (mod c)
* Returns: 0 on success, -1 on failure
*/
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;
}
/**
* bignum_exptmod - Modular exponentiation: d = a^b (mod c)
* @a: Bignum from bignum_init(); base
* @b: Bignum from bignum_init(); exponent
* @c: Bignum from bignum_init(); modulus
* @d: Bignum from bignum_init(); used to store the result of a^b (mod c)
* Returns: 0 on success, -1 on failure
*/
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;
}