mirror of
https://github.com/trezor/trezor-firmware.git
synced 2024-11-23 07:58:09 +00:00
110 lines
4.1 KiB
C
110 lines
4.1 KiB
C
/*
|
|
* Copyright (c) Pavol Rusnak, SatoshiLabs
|
|
*
|
|
* Licensed under TREZOR License
|
|
* see LICENSE file for details
|
|
*/
|
|
|
|
#include "py/objstr.h"
|
|
|
|
#include "trezor-crypto/bignum.h"
|
|
#include "ssss.h"
|
|
|
|
typedef struct _mp_obj_SSSS_t {
|
|
mp_obj_base_t base;
|
|
} mp_obj_SSSS_t;
|
|
|
|
STATIC mp_obj_t mod_TrezorCrypto_SSSS_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *args) {
|
|
mp_arg_check_num(n_args, n_kw, 0, 0, false);
|
|
mp_obj_SSSS_t *o = m_new_obj(mp_obj_SSSS_t);
|
|
o->base.type = type;
|
|
return MP_OBJ_FROM_PTR(o);
|
|
}
|
|
|
|
/// def trezor.crypto.ssss.split(m: int, n: int, secret: bytes) -> tuple:
|
|
/// '''
|
|
/// Split secret to (M of N) shares using Shamir's Secret Sharing Scheme
|
|
/// '''
|
|
STATIC mp_obj_t mod_TrezorCrypto_SSSS_split(size_t n_args, const mp_obj_t *args) {
|
|
mp_int_t m = mp_obj_get_int(args[1]);
|
|
mp_int_t n = mp_obj_get_int(args[2]);
|
|
mp_buffer_info_t secret;
|
|
mp_get_buffer_raise(args[3], &secret, MP_BUFFER_READ);
|
|
if (secret.len != 32) {
|
|
nlr_raise(mp_obj_new_exception_msg(&mp_type_ValueError, "Length of the secret has to be 256 bits"));
|
|
}
|
|
if (m < 1 || n < 1 || m > 15 || n > 15 || m > n) {
|
|
nlr_raise(mp_obj_new_exception_msg(&mp_type_ValueError, "Invalid number of shares"));
|
|
}
|
|
bignum256 sk;
|
|
bignum256 shares[n];
|
|
bn_read_be(secret.buf, &sk);
|
|
if (!ssss_split(&sk, m, n, shares)) {
|
|
nlr_raise(mp_obj_new_exception_msg(&mp_type_ValueError, "Error splitting secret"));
|
|
}
|
|
mp_obj_tuple_t *tuple = MP_OBJ_TO_PTR(mp_obj_new_tuple(n, NULL));
|
|
vstr_t vstr[n];
|
|
for (int i = 0; i < n; i++) {
|
|
vstr_init_len(&vstr[i], secret.len);
|
|
bn_write_be(&shares[i], secret.buf);
|
|
tuple->items[i] = mp_obj_new_str_from_vstr(&mp_type_bytes, &vstr[i]);
|
|
}
|
|
return MP_OBJ_FROM_PTR(tuple);
|
|
}
|
|
STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(mod_TrezorCrypto_SSSS_split_obj, 4, 4, mod_TrezorCrypto_SSSS_split);
|
|
|
|
/// def trezor.crypto.ssss.combine(shares: tuple) -> bytes:
|
|
/// '''
|
|
/// Combine M shares of Shamir's Secret Sharing Scheme into secret
|
|
/// '''
|
|
STATIC mp_obj_t mod_TrezorCrypto_SSSS_combine(mp_obj_t self, mp_obj_t shares) {
|
|
mp_uint_t n;
|
|
mp_obj_t *share;
|
|
if (MP_OBJ_IS_TYPE(shares, &mp_type_tuple)) {
|
|
mp_obj_tuple_get(shares, &n, &share);
|
|
} else
|
|
if (MP_OBJ_IS_TYPE(shares, &mp_type_list)) {
|
|
mp_obj_list_get(shares, &n, &share);
|
|
} else {
|
|
nlr_raise(mp_obj_new_exception_msg(&mp_type_ValueError, "List or tuple expected"));
|
|
}
|
|
if (n < 1 || n > 15) {
|
|
nlr_raise(mp_obj_new_exception_msg(&mp_type_ValueError, "Invalid number of shares"));
|
|
}
|
|
bignum256 bnshares[n];
|
|
for (mp_uint_t i = 0; i < n; i++) {
|
|
if (MP_OBJ_IS_TYPE(share[i], &mp_type_bytes)) {
|
|
mp_buffer_info_t s;
|
|
mp_get_buffer_raise(share[i], &s, MP_BUFFER_READ);
|
|
if (s.len != 32) {
|
|
nlr_raise(mp_obj_new_exception_msg(&mp_type_ValueError, "Length of share has to be 256 bits"));
|
|
}
|
|
bn_read_be(s.buf, &bnshares[n]);
|
|
} else {
|
|
memset(&bnshares[i], 0, sizeof(bignum256));
|
|
}
|
|
}
|
|
bignum256 sk;
|
|
if (!ssss_combine(bnshares, n, &sk)) {
|
|
nlr_raise(mp_obj_new_exception_msg(&mp_type_ValueError, "Error combining secret"));
|
|
}
|
|
vstr_t vstr;
|
|
vstr_init_len(&vstr, 32);
|
|
bn_write_be(&sk, (uint8_t *)vstr.buf);
|
|
return mp_obj_new_str_from_vstr(&mp_type_bytes, &vstr);
|
|
}
|
|
STATIC MP_DEFINE_CONST_FUN_OBJ_2(mod_TrezorCrypto_SSSS_combine_obj, mod_TrezorCrypto_SSSS_combine);
|
|
|
|
STATIC const mp_rom_map_elem_t mod_TrezorCrypto_SSSS_locals_dict_table[] = {
|
|
{ MP_ROM_QSTR(MP_QSTR_split), MP_ROM_PTR(&mod_TrezorCrypto_SSSS_split_obj) },
|
|
{ MP_ROM_QSTR(MP_QSTR_combine), MP_ROM_PTR(&mod_TrezorCrypto_SSSS_combine_obj) },
|
|
};
|
|
STATIC MP_DEFINE_CONST_DICT(mod_TrezorCrypto_SSSS_locals_dict, mod_TrezorCrypto_SSSS_locals_dict_table);
|
|
|
|
STATIC const mp_obj_type_t mod_TrezorCrypto_SSSS_type = {
|
|
{ &mp_type_type },
|
|
.name = MP_QSTR_SSSS,
|
|
.make_new = mod_TrezorCrypto_SSSS_make_new,
|
|
.locals_dict = (void*)&mod_TrezorCrypto_SSSS_locals_dict,
|
|
};
|