Remove RtlGenRandom implementation

Also remove outdated comment from windows_uwp.rs

build.rs

@@ -4,12 +4,9 @@ use std::env;
 
 fn main() {
     let target = env::var("TARGET").expect("TARGET was not set");
-    if target.contains("-uwp-windows-") {
+    if target.contains("windows") {
         // for BCryptGenRandom
         println!("cargo:rustc-link-lib=bcrypt");
-    } else if target.contains("windows") {
-        // for RtlGenRandom (aka SystemFunction036)
-        println!("cargo:rustc-link-lib=advapi32");
     } else if target.contains("apple-ios") {
         // for SecRandomCopyBytes and kSecRandomDefault
         println!("cargo:rustc-link-lib=framework=Security");

src/lib.rs

@@ -13,8 +13,7 @@
 //! | Target            | Target Triple      | Implementation
 //! | ----------------- | ------------------ | --------------
 //! | Linux, Android    | `*‑linux‑*`        | [`getrandom`][1] system call if available, otherwise [`/dev/urandom`][2] after successfully polling `/dev/random` |
-//! | Windows           | `*‑pc‑windows‑*`   | [`RtlGenRandom`][3] |
-//! | [Windows UWP][22] | `*‑uwp‑windows‑*`  | [`BCryptGenRandom`][23] |
+//! | Windows           | `*‑pc‑windows‑*`   | [`BCryptGenRandom`][3] |
 //! | macOS             | `*‑apple‑darwin`   | [`getentropy()`][19] if available, otherwise [`/dev/random`][20] (identical to `/dev/urandom`)
 //! | iOS               | `*‑apple‑ios`      | [`SecRandomCopyBytes`][4]
 //! | FreeBSD           | `*‑freebsd`        | [`getrandom()`][21] if available, otherwise [`kern.arandom`][5]
@@ -121,7 +120,7 @@
 //!
 //! [1]: http://man7.org/linux/man-pages/man2/getrandom.2.html
 //! [2]: http://man7.org/linux/man-pages/man4/urandom.4.html
-//! [3]: https://docs.microsoft.com/en-us/windows/desktop/api/ntsecapi/nf-ntsecapi-rtlgenrandom
+//! [3]: https://docs.microsoft.com/en-us/windows/win32/api/bcrypt/nf-bcrypt-bcryptgenrandom
 //! [4]: https://developer.apple.com/documentation/security/1399291-secrandomcopybytes?language=objc
 //! [5]: https://www.freebsd.org/cgi/man.cgi?query=random&sektion=4
 //! [6]: https://man.openbsd.org/getentropy.2
@@ -139,8 +138,6 @@
 //! [19]: https://www.unix.com/man-page/mojave/2/getentropy/
 //! [20]: https://www.unix.com/man-page/mojave/4/random/
 //! [21]: https://www.freebsd.org/cgi/man.cgi?query=getrandom&manpath=FreeBSD+12.0-stable
-//! [22]: https://docs.microsoft.com/en-us/windows/uwp/
-//! [23]: https://docs.microsoft.com/en-us/windows/win32/api/bcrypt/nf-bcrypt-bcryptgenrandom
 
 #![doc(
     html_logo_url = "https://www.rust-lang.org/logos/rust-logo-128x128-blk.png",
@@ -201,10 +198,8 @@ cfg_if! {
     } else if #[cfg(target_os = "vxworks")] {
         mod util_libc;
         #[path = "vxworks.rs"] mod imp;
-    } else if #[cfg(all(windows, target_vendor = "uwp"))] {
-        #[path = "windows_uwp.rs"] mod imp;
     } else if #[cfg(windows)] {
-        #[path = "windows.rs"] mod imp;
+        #[path = "windows_uwp.rs"] mod imp;
     } else if #[cfg(all(target_arch = "x86_64", target_env = "sgx"))] {
         #[path = "rdrand.rs"] mod imp;
     } else if #[cfg(all(feature = "rdrand",

src/windows.rs

@@ -1,26 +0,0 @@
-// 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 Windows
-use crate::Error;
-
-extern "system" {
-    #[link_name = "SystemFunction036"]
-    fn RtlGenRandom(RandomBuffer: *mut u8, RandomBufferLength: u32) -> u8;
-}
-
-pub fn getrandom_inner(dest: &mut [u8]) -> Result<(), Error> {
-    // Prevent overflow of u32
-    for chunk in dest.chunks_mut(u32::max_value() as usize) {
-        let ret = unsafe { RtlGenRandom(chunk.as_mut_ptr(), chunk.len() as u32) };
-        if ret == 0 {
-            return Err(Error::WINDOWS_RTL_GEN_RANDOM);
-        }
-    }
-    Ok(())
-}

src/windows_uwp.rs

@@ -6,8 +6,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-//! Implementation for Windows UWP targets. After deprecation of Windows XP
-//! and Vista, this can supersede the `RtlGenRandom`-based implementation.
 use crate::Error;
 use core::{ffi::c_void, num::NonZeroU32, ptr};