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use crate::{FromInner, Inner, IntoInner};
use uv::{uv_random, uv_random_t};
callbacks! {
pub RandomCB(
req: RandomReq,
status: crate::Result<u32>,
buf: Vec<u8>
);
}
/// Additional data stored on the request
pub(crate) struct RandomDataFields<'a> {
random_cb: RandomCB<'a>,
}
/// Callback for uv_random
extern "C" fn uv_random_cb(
req: *mut uv_random_t,
status: std::os::raw::c_int,
buf: *mut std::os::raw::c_void,
buflen: usize,
) {
let dataptr = crate::Req::get_data(uv_handle!(req));
if !dataptr.is_null() {
unsafe {
if let super::RandomData(d) = &mut *dataptr {
let buf = Vec::from_raw_parts(buf as _, buflen as _, buflen as _);
let status = if status < 0 {
Err(crate::Error::from_inner(status as uv::uv_errno_t))
} else {
Ok(status as _)
};
d.random_cb.call(req.into_inner(), status, buf);
}
}
}
// free memory
let mut req = RandomReq::from_inner(req);
req.destroy();
}
/// Random data request type.
#[derive(Clone, Copy)]
pub struct RandomReq {
req: *mut uv_random_t,
}
impl RandomReq {
/// Create a new random request
pub fn new<CB: Into<RandomCB<'static>>>(cb: CB) -> crate::Result<RandomReq> {
let layout = std::alloc::Layout::new::<uv_random_t>();
let req = unsafe { std::alloc::alloc(layout) as *mut uv_random_t };
if req.is_null() {
return Err(crate::Error::ENOMEM);
}
let random_cb = cb.into();
crate::Req::initialize_data(
uv_handle!(req),
super::RandomData(RandomDataFields { random_cb }),
);
Ok(RandomReq { req })
}
/// Free memory - this will be called automatically after the callback (if using the async
/// function), or before returning the random data (if using the sync version)
pub fn destroy(&mut self) {
crate::Req::free_data(uv_handle!(self.req));
let layout = std::alloc::Layout::new::<uv_random_t>();
unsafe { std::alloc::dealloc(self.req as _, layout) };
}
}
impl FromInner<*mut uv_random_t> for RandomReq {
fn from_inner(req: *mut uv_random_t) -> RandomReq {
RandomReq { req }
}
}
impl Inner<*mut uv_random_t> for RandomReq {
fn inner(&self) -> *mut uv_random_t {
self.req
}
}
impl Inner<*mut uv::uv_req_t> for RandomReq {
fn inner(&self) -> *mut uv::uv_req_t {
uv_handle!(self.req)
}
}
impl From<RandomReq> for crate::Req {
fn from(random: RandomReq) -> crate::Req {
crate::Req::from_inner(Inner::<*mut uv::uv_req_t>::inner(&random))
}
}
impl crate::ToReq for RandomReq {
fn to_req(&self) -> crate::Req {
crate::Req::from_inner(Inner::<*mut uv::uv_req_t>::inner(self))
}
}
impl crate::ReqTrait for RandomReq {}
impl crate::Loop {
/// Fill a buf with exactly buflen cryptographically strong random bytes acquired from the
/// system CSPRNG. flags is reserved for future extension and must currently be 0.
///
/// Short reads are not possible. When less than buflen random bytes are available, a non-zero
/// error value is returned or passed to the callback.
///
/// The asynchronous version may not ever finish when the system is low on entropy.
///
/// Sources of entropy:
///
/// * Windows: RtlGenRandom
/// <https://docs.microsoft.com/en-us/windows/desktop/api/ntsecapi/nf-ntsecapi-rtlgenrandom>_.
/// * Linux, Android: getrandom(2) if available, or urandom(4) after reading from /dev/random
/// once, or the KERN_RANDOM sysctl(2).
/// * FreeBSD: getrandom(2) <https://www.freebsd.org/cgi/man.cgi?query=getrandom&sektion=2>_,
/// or /dev/urandom after reading from /dev/random once.
/// * NetBSD: KERN_ARND sysctl(7) <https://man.netbsd.org/sysctl.7>_
/// * macOS, OpenBSD: getentropy(2) <https://man.openbsd.org/getentropy.2>_ if available, or
/// /dev/urandom after reading from /dev/random once.
/// * AIX: /dev/random.
/// * IBM i: /dev/urandom.
/// * Other UNIX: /dev/urandom after reading from /dev/random once.
pub fn random<CB: Into<RandomCB<'static>>>(
&self,
buflen: usize,
flags: u32,
cb: CB,
) -> crate::Result<RandomReq> {
let mut req = RandomReq::new(cb)?;
let mut buf = std::mem::ManuallyDrop::new(Vec::<u8>::with_capacity(buflen));
let result = crate::uvret(unsafe {
uv_random(
self.into_inner(),
req.inner(),
buf.as_mut_ptr() as _,
buflen as _,
flags as _,
Some(uv_random_cb as _),
)
});
if result.is_err() {
req.destroy();
}
result.map(|_| req)
}
/// Fill a buf with exactly buflen cryptographically strong random bytes acquired from the
/// system CSPRNG. flags is reserved for future extension and must currently be 0.
///
/// Short reads are not possible. When less than buflen random bytes are available, a non-zero
/// error value is returned or passed to the callback.
///
/// The synchronous version may block indefinitely when not enough entropy is available.
///
/// Sources of entropy:
///
/// * Windows: RtlGenRandom
/// <https://docs.microsoft.com/en-us/windows/desktop/api/ntsecapi/nf-ntsecapi-rtlgenrandom>_.
/// * Linux, Android: getrandom(2) if available, or urandom(4) after reading from /dev/random
/// once, or the KERN_RANDOM sysctl(2).
/// * FreeBSD: getrandom(2) <https://www.freebsd.org/cgi/man.cgi?query=getrandom&sektion=2>_,
/// or /dev/urandom after reading from /dev/random once.
/// * NetBSD: KERN_ARND sysctl(7) <https://man.netbsd.org/sysctl.7>_
/// * macOS, OpenBSD: getentropy(2) <https://man.openbsd.org/getentropy.2>_ if available, or
/// /dev/urandom after reading from /dev/random once.
/// * AIX: /dev/random.
/// * IBM i: /dev/urandom.
/// * Other UNIX: /dev/urandom after reading from /dev/random once.
pub fn random_sync(buflen: usize, flags: u32) -> crate::Result<Vec<u8>> {
let mut buf: Vec<u8> = Vec::with_capacity(buflen);
unsafe { buf.set_len(buflen) };
crate::uvret(unsafe {
uv_random(
std::ptr::null_mut(),
std::ptr::null_mut(),
buf.as_mut_ptr() as _,
buflen as _,
flags as _,
None::<
unsafe extern "C" fn(
*mut uv_random_t,
std::os::raw::c_int,
*mut std::os::raw::c_void,
usize,
),
>,
)
})
.map(|_| buf)
}
}