modos.c

/*
 * This file is part of the MicroPython project, http://micropython.org/
 *
 * Development of the code in this file was sponsored by Microbric Pty Ltd
 *
 * The MIT License (MIT)
 *
 * Copyright (c) 2015 Josef Gajdusek
 * Copyright (c) 2016 Damien P. George
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

// This file is never compiled standalone, it's included directly from
// extmod/modos.c via MICROPY_PY_OS_INCLUDEFILE.

#include "esp_system.h"

#include "py/runtime.h"
#include "py/mphal.h"
#include "extmod/misc.h"

static mp_obj_t mp_os_urandom(mp_obj_t num) {
    mp_int_t n = mp_obj_get_int(num);
    vstr_t vstr;
    vstr_init_len(&vstr, n);
    uint32_t r = 0;
    for (int i = 0; i < n; i++) {
        if ((i & 3) == 0) {
            r = esp_random(); // returns 32-bit hardware random number
        }
        vstr.buf[i] = r;
        r >>= 8;
    }
    return mp_obj_new_bytes_from_vstr(&vstr);
}
static MP_DEFINE_CONST_FUN_OBJ_1(mp_os_urandom_obj, mp_os_urandom);