void
nettle_mpz_init_set_str_256_s(mpz_t x,
size_t length, const uint8_t *s)
{
mpz_init(x);
nettle_mpz_set_str_256_s(x, length, s);
}
int
parse_bignum(struct simple_buffer *buffer, mpz_t result, uint32_t limit)
{
uint32_t length;
const uint8_t *digits;
if (!parse_string(buffer, &length, &digits))
return 0;
/* NOTE: If the reciever expects an integer less than 256^limit,
* there may still be limit + 1 digits, as a leading zero is
* sometimes required to resolve signedness. */
if (limit && (length > (limit + 1)))
return 0;
nettle_mpz_set_str_256_s(result, length, digits);
return 1;
}
static int
wrap_nettle_mpi_scan(bigint_t r, const void *buffer, size_t nbytes,
gnutls_bigint_format_t format)
{
if (format == GNUTLS_MPI_FORMAT_USG) {
nettle_mpz_set_str_256_u(TOMPZ(r), nbytes, buffer);
} else if (format == GNUTLS_MPI_FORMAT_STD) {
nettle_mpz_set_str_256_s(TOMPZ(r), nbytes, buffer);
#if ENABLE_GOST
} else if (format == GNUTLS_MPI_FORMAT_ULE) {
nettle_mpz_set_str_256_u_le(TOMPZ(r), nbytes, buffer);
#endif
} else {
gnutls_assert();
goto fail;
}
return 0;
fail:
return GNUTLS_E_MPI_SCAN_FAILED;
}
int
nettle_mpz_set_sexp(mpz_t x, unsigned limit, struct sexp_iterator *i)
{
if (i->type == SEXP_ATOM
&& i->atom_length
&& !i->display)
{
/* Allow some extra here, for leading sign octets. */
if (limit && (8 * i->atom_length > (16 + limit)))
return 0;
nettle_mpz_set_str_256_s(x, i->atom_length, i->atom);
/* FIXME: How to interpret a limit for negative numbers? */
if (limit && mpz_sizeinbase(x, 2) > limit)
return 0;
return sexp_iterator_next(i);
}
else
return 0;
}
int
asn1_der_get_bignum(struct asn1_der_iterator *i,
mpz_t x, unsigned max_bits)
{
if (i->length > 1
&& ((i->data[0] == 0 && i->data[1] < 0x80)
|| (i->data[0] == 0xff && i->data[1] >= 0x80)))
/* Non-minimal number of digits */
return 0;
/* Allow some extra here, for leading sign octets. */
if (max_bits && (8 * i->length > (16 + max_bits)))
return 0;
nettle_mpz_set_str_256_s(x, i->length, i->data);
/* FIXME: How to interpret a max_bits for negative numbers? */
if (max_bits && mpz_sizeinbase(x, 2) > max_bits)
return 0;
return 1;
}
