27 lines
1.1 KiB
Rust
27 lines
1.1 KiB
Rust
// Copyright 2021 Developers of the Rand project.
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//
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// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
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// https://www.apache.org/licenses/LICENSE-2.0> or the MIT license
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// <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your
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// option. This file may not be copied, modified, or distributed
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// except according to those terms.
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//! Implementation for ESP-IDF
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use crate::Error;
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use core::ffi::c_void;
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extern "C" {
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fn esp_fill_random(buf: *mut c_void, len: usize) -> u32;
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}
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pub fn getrandom_inner(dest: &mut [u8]) -> Result<(), Error> {
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// Not that NOT enabling WiFi, BT, or the voltage noise entropy source (via `bootloader_random_enable`)
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// will cause ESP-IDF to return pseudo-random numbers based on the voltage noise entropy, after the initial boot process:
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// https://docs.espressif.com/projects/esp-idf/en/latest/esp32/api-reference/system/random.html
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//
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// However tracking if some of these entropy sources is enabled is way too difficult to implement here
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unsafe { esp_fill_random(dest.as_mut_ptr().cast(), dest.len()) };
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Ok(())
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}
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