1 files changed, 25 insertions, 0 deletions
diff --git a/third_party/rust/getrandom/src/wasi.rs b/third_party/rust/getrandom/src/wasi.rs
new file mode 100644
index 0000000000..9276ee74f8
--- /dev/null
+++ b/third_party/rust/getrandom/src/wasi.rs
@@ -0,0 +1,25 @@
+// Copyright 2018 Developers of the Rand project.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// https://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+//! Implementation for WASI
+use crate::Error;
+use core::{
+    mem::MaybeUninit,
+    num::{NonZeroU16, NonZeroU32},
+};
+use wasi::random_get;
+
+pub fn getrandom_inner(dest: &mut [MaybeUninit<u8>]) -> Result<(), Error> {
+    unsafe { random_get(dest.as_mut_ptr() as *mut u8, dest.len()) }.map_err(|e| {
+        // The WASI errno will always be non-zero, but we check just in case.
+        match NonZeroU16::new(e.raw()) {
+            Some(r) => Error::from(NonZeroU32::from(r)),
+            None => Error::ERRNO_NOT_POSITIVE,
+        }
+    })
+}