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trezor-firmware/embed/extmod/modtrezorcrypto/modtrezorcrypto-random.h
2018-02-26 14:07:37 +01:00

91 lines
3.2 KiB
C

/*
* This file is part of the TREZOR project, https://trezor.io/
*
* Copyright (c) SatoshiLabs
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "py/objstr.h"
#include "rand.h"
/// def uniform(n: int) -> int:
/// '''
/// Compute uniform random number from interval 0 ... n - 1.
/// '''
STATIC mp_obj_t mod_trezorcrypto_random_uniform(mp_obj_t n) {
uint32_t nn = mp_obj_get_int_truncated(n);
if (nn == 0) {
mp_raise_ValueError("Maximum can't be zero");
}
return mp_obj_new_int_from_uint(random_uniform(nn));
}
STATIC MP_DEFINE_CONST_FUN_OBJ_1(mod_trezorcrypto_random_uniform_obj, mod_trezorcrypto_random_uniform);
/// def bytes(len: int) -> bytes:
/// '''
/// Generate random bytes sequence of length len.
/// '''
STATIC mp_obj_t mod_trezorcrypto_random_bytes(mp_obj_t len) {
uint32_t l = mp_obj_get_int(len);
if (l > 1024) {
mp_raise_ValueError("Maximum requested size is 1024");
}
vstr_t vstr;
vstr_init_len(&vstr, l);
random_buffer((uint8_t *)vstr.buf, l);
return mp_obj_new_str_from_vstr(&mp_type_bytes, &vstr);
}
STATIC MP_DEFINE_CONST_FUN_OBJ_1(mod_trezorcrypto_random_bytes_obj, mod_trezorcrypto_random_bytes);
/// def shuffle(data: list) -> None:
/// '''
/// Shuffles items of given list (in-place).
/// '''
STATIC mp_obj_t mod_trezorcrypto_random_shuffle(mp_obj_t data) {
size_t count;
mp_obj_t *items;
mp_obj_get_array(data, &count, &items);
if (count > 256) {
mp_raise_ValueError("Maximum list size is 256 items");
}
if (count <= 1) {
return mp_const_none;
}
// Fisher-Yates shuffle
mp_obj_t t;
for (size_t i = count - 1; i >= 1; i--) {
size_t j = random_uniform(i + 1);
t = items[i];
items[i] = items[j];
items[j] = t;
}
return mp_const_none;
}
STATIC MP_DEFINE_CONST_FUN_OBJ_1(mod_trezorcrypto_random_shuffle_obj, mod_trezorcrypto_random_shuffle);
STATIC const mp_rom_map_elem_t mod_trezorcrypto_random_globals_table[] = {
{ MP_ROM_QSTR(MP_QSTR___name__), MP_ROM_QSTR(MP_QSTR_random) },
{ MP_ROM_QSTR(MP_QSTR_uniform), MP_ROM_PTR(&mod_trezorcrypto_random_uniform_obj) },
{ MP_ROM_QSTR(MP_QSTR_bytes), MP_ROM_PTR(&mod_trezorcrypto_random_bytes_obj) },
{ MP_ROM_QSTR(MP_QSTR_shuffle), MP_ROM_PTR(&mod_trezorcrypto_random_shuffle_obj) },
};
STATIC MP_DEFINE_CONST_DICT(mod_trezorcrypto_random_globals, mod_trezorcrypto_random_globals_table);
STATIC const mp_obj_module_t mod_trezorcrypto_random_module = {
.base = { &mp_type_module },
.globals = (mp_obj_dict_t*)&mod_trezorcrypto_random_globals,
};