redox/schemes/randd/src/main.rs

60 lines
1.5 KiB
Rust

#![feature(asm)]
extern crate syscall;
use std::fs::File;
use std::io::{Read, Write};
use std::thread;
use syscall::{Packet, Result, Scheme};
//TODO: Use a CSPRNG, allow write of entropy
struct RandScheme;
impl Scheme for RandScheme {
fn open(&self, _path: &[u8], _flags: usize, _uid: u32, _gid: u32) -> Result<usize> {
Ok(0)
}
fn dup(&self, file: usize) -> Result<usize> {
Ok(file)
}
fn read(&self, _file: usize, buf: &mut [u8]) -> Result<usize> {
let mut i = 0;
for chunk in buf.chunks_mut(8) {
let mut rand: u64;
unsafe {
asm!("rdrand rax"
: "={rax}"(rand)
:
:
: "intel", "volatile");
}
for b in chunk.iter_mut() {
*b = rand as u8;
rand = rand >> 8;
i += 1;
}
}
Ok(i)
}
fn close(&self, _file: usize) -> Result<usize> {
Ok(0)
}
}
fn main(){
thread::spawn(move || {
let mut socket = File::create(":rand").expect("rand: failed to create rand scheme");
let scheme = RandScheme;
loop {
let mut packet = Packet::default();
socket.read(&mut packet).expect("rand: failed to read events from rand scheme");
scheme.handle(&mut packet);
socket.write(&packet).expect("rand: failed to write responses to rand scheme");
}
});
}