/*
* TEE_BigIntConvertFromFMM
*/
void TEE_BigIntConvertFromFMM(TEE_BigInt *dest,
const TEE_BigIntFMM *src,
const TEE_BigInt *n,
const TEE_BigIntFMMContext *context)
{
mpanum mpa_dest = (mpa_num_base *)dest;
mpanum mpa_op2 = (mpa_num_base *)src;
mpanum mpa_n = (mpa_num_base *)n;
mpa_fmm_context mpa_context = (mpa_fmm_context_base *)context;
mpanum temp_dest;
/*
* Since dest in BigIntFFMCompute (i.e. dest in mpa_montgomery_mul)
* must have alloc one word more than the size of n, we must
* use a temp variable during the conversion.
*/
mpa_alloc_static_temp_var(&temp_dest, mempool);
/* calculate dest = Mont(1,src) */
mpa_montgomery_mul(temp_dest, mpa_constant_one(), mpa_op2, mpa_n,
mpa_context->n_inv, mempool);
mpa_copy(mpa_dest, temp_dest);
mpa_free_static_temp_var(&temp_dest, mempool);
}
/* reduce */
static int montgomery_reduce(void *a, void *b, void *c)
{
LTC_ARGCHK(a != NULL);
LTC_ARGCHK(b != NULL);
LTC_ARGCHK(c != NULL);
mpanum tmp;
init((void **)&tmp);
// WARNING
// Workaround for a bug when a > b (a greater than the modulus)
if (compare(a, b) == LTC_MP_GT) {
mpa_mod((mpanum) a, (const mpanum) a, (const mpanum) b, external_mem_pool);
}
mpa_montgomery_mul(tmp,
(mpanum) a,
mpa_constant_one(),
(mpanum) b,
((mpa_fmm_context) c)->n_inv,
external_mem_pool);
mpa_copy(a, tmp);
deinit(tmp);
return CRYPT_OK;
}