feat: add getrandom implementation

Cargo.lock

@@ -69,6 +69,18 @@ version = "1.15.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "48c757948c5ede0e46177b7add2e67155f70e33c07fea8284df6576da70b3719"
 
+[[package]]
+name = "getrandom"
+version = "0.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "43a49c392881ce6d5c3b8cb70f98717b7c07aabbdff06687b9030dbfbe2725f8"
+dependencies = [
+ "cfg-if",
+ "libc",
+ "wasi",
+ "windows-targets",
+]
+
 [[package]]
 name = "glob"
 version = "0.3.2"
@@ -129,6 +141,8 @@ name = "mlkem-native-rs"
 version = "0.1.0"
 dependencies = [
  "bindgen",
+ "getrandom",
+ "libc",
  "make-cmd",
 ]
 
@@ -228,6 +242,15 @@ version = "1.0.18"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "5a5f39404a5da50712a4c1eecf25e90dd62b613502b7e925fd4e4d19b5c96512"
 
+[[package]]
+name = "wasi"
+version = "0.13.3+wasi-0.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "26816d2e1a4a36a2940b96c5296ce403917633dff8f3440e9b236ed6f6bacad2"
+dependencies = [
+ "wit-bindgen-rt",
+]
+
 [[package]]
 name = "windows-targets"
 version = "0.52.6"
@@ -291,3 +314,12 @@ name = "windows_x86_64_msvc"
 version = "0.52.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "589f6da84c646204747d1270a2a5661ea66ed1cced2631d546fdfb155959f9ec"
+
+[[package]]
+name = "wit-bindgen-rt"
+version = "0.33.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3268f3d866458b787f390cf61f4bbb563b922d091359f9608842999eaee3943c"
+dependencies = [
+ "bitflags",
+]

Cargo.toml

@@ -5,6 +5,8 @@ version = "0.1.0"
 edition = "2021"
 
 [dependencies]
+getrandom = "0.3.1"
+libc = "0.2.171"
 
 [build-dependencies]
 bindgen = "0.71.1"

src/lib.rs

@@ -2,4 +2,13 @@
 #![allow(non_camel_case_types)]
 #![allow(non_snake_case)]
 
+use std::slice;
+
 include!(concat!(env!("OUT_DIR"), "/bindings.rs"));
+
+#[no_mangle]
+pub unsafe extern "C" fn randombytes(buf: *mut u8, len: libc::size_t) -> libc::c_int {
+    let buf = slice::from_raw_parts_mut(buf, len);
+    getrandom::fill(buf).expect("RNG Failed");
+    0
+}