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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 12:02:58 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 12:02:58 +0000 |
commit | 698f8c2f01ea549d77d7dc3338a12e04c11057b9 (patch) | |
tree | 173a775858bd501c378080a10dca74132f05bc50 /vendor/getrandom/src/lib.rs | |
parent | Initial commit. (diff) | |
download | rustc-698f8c2f01ea549d77d7dc3338a12e04c11057b9.tar.xz rustc-698f8c2f01ea549d77d7dc3338a12e04c11057b9.zip |
Adding upstream version 1.64.0+dfsg1.upstream/1.64.0+dfsg1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'vendor/getrandom/src/lib.rs')
-rw-r--r-- | vendor/getrandom/src/lib.rs | 263 |
1 files changed, 263 insertions, 0 deletions
diff --git a/vendor/getrandom/src/lib.rs b/vendor/getrandom/src/lib.rs new file mode 100644 index 000000000..888b9a510 --- /dev/null +++ b/vendor/getrandom/src/lib.rs @@ -0,0 +1,263 @@ +// Copyright 2019 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. + +//! Interface to the operating system's random number generator. +//! +//! # Supported targets +//! +//! | Target | Target Triple | Implementation +//! | ----------------- | ------------------ | -------------- +//! | Linux, Android | `*‑linux‑*` | [`getrandom`][1] system call if available, otherwise [`/dev/urandom`][2] after successfully polling `/dev/random` +//! | Windows | `*‑windows‑*` | [`BCryptGenRandom`] +//! | macOS | `*‑apple‑darwin` | [`getentropy`][3] if available, otherwise [`/dev/random`][4] (identical to `/dev/urandom`) +//! | iOS | `*‑apple‑ios` | [`SecRandomCopyBytes`] +//! | FreeBSD | `*‑freebsd` | [`getrandom`][5] if available, otherwise [`kern.arandom`][6] +//! | OpenBSD | `*‑openbsd` | [`getentropy`][7] +//! | NetBSD | `*‑netbsd` | [`kern.arandom`][8] +//! | Dragonfly BSD | `*‑dragonfly` | [`getrandom`][9] if available, otherwise [`/dev/random`][10] +//! | Solaris, illumos | `*‑solaris`, `*‑illumos` | [`getrandom`][11] if available, otherwise [`/dev/random`][12] +//! | Fuchsia OS | `*‑fuchsia` | [`cprng_draw`] +//! | Redox | `*‑redox` | `/dev/urandom` +//! | Haiku | `*‑haiku` | `/dev/random` (identical to `/dev/urandom`) +//! | Hermit | `x86_64-*-hermit` | [`RDRAND`] +//! | SGX | `x86_64‑*‑sgx` | [`RDRAND`] +//! | VxWorks | `*‑wrs‑vxworks‑*` | `randABytes` after checking entropy pool initialization with `randSecure` +//! | ESP-IDF | `*‑espidf` | [`esp_fill_random`] +//! | Emscripten | `*‑emscripten` | `/dev/random` (identical to `/dev/urandom`) +//! | WASI | `wasm32‑wasi` | [`random_get`] +//! | Web Browser | `wasm32‑*‑unknown` | [`Crypto.getRandomValues`], see [WebAssembly support] +//! | Node.js | `wasm32‑*‑unknown` | [`crypto.randomBytes`], see [WebAssembly support] +//! | SOLID | `*-kmc-solid_*` | `SOLID_RNG_SampleRandomBytes` +//! | Nintendo 3DS | `armv6k-nintendo-3ds` | [`getrandom`][1] +//! +//! There is no blanket implementation on `unix` targets that reads from +//! `/dev/urandom`. This ensures all supported targets are using the recommended +//! interface and respect maximum buffer sizes. +//! +//! Pull Requests that add support for new targets to `getrandom` are always welcome. +//! +//! ## Unsupported targets +//! +//! By default, `getrandom` will not compile on unsupported targets, but certain +//! features allow a user to select a "fallback" implementation if no supported +//! implementation exists. +//! +//! All of the below mechanisms only affect unsupported +//! targets. Supported targets will _always_ use their supported implementations. +//! This prevents a crate from overriding a secure source of randomness +//! (either accidentally or intentionally). +//! +//! ### RDRAND on x86 +//! +//! *If the `rdrand` Cargo feature is enabled*, `getrandom` will fallback to using +//! the [`RDRAND`] instruction to get randomness on `no_std` `x86`/`x86_64` +//! targets. This feature has no effect on other CPU architectures. +//! +//! ### WebAssembly support +//! +//! This crate fully supports the +//! [`wasm32-wasi`](https://github.com/CraneStation/wasi) and +//! [`wasm32-unknown-emscripten`](https://www.hellorust.com/setup/emscripten/) +//! targets. However, the `wasm32-unknown-unknown` target (i.e. the target used +//! by `wasm-pack`) is not automatically +//! supported since, from the target name alone, we cannot deduce which +//! JavaScript interface is in use (or if JavaScript is available at all). +//! +//! Instead, *if the `js` Cargo feature is enabled*, this crate will assume +//! that you are building for an environment containing JavaScript, and will +//! call the appropriate methods. Both web browser (main window and Web Workers) +//! and Node.js environments are supported, invoking the methods +//! [described above](#supported-targets) using the +//! [wasm-bindgen](https://github.com/rust-lang/rust-bindgen) toolchain. +//! +//! This feature has no effect on targets other than `wasm32-unknown-unknown`. +//! +//! ### Custom implementations +//! +//! The [`register_custom_getrandom!`] macro allows a user to mark their own +//! function as the backing implementation for [`getrandom`]. See the macro's +//! documentation for more information about writing and registering your own +//! custom implementations. +//! +//! Note that registering a custom implementation only has an effect on targets +//! that would otherwise not compile. Any supported targets (including those +//! using `rdrand` and `js` Cargo features) continue using their normal +//! implementations even if a function is registered. +//! +//! ### Indirect Dependencies +//! +//! If `getrandom` is not a direct dependency of your crate, you can still +//! enable any of the above fallback behaviors by enabling the relevant +//! feature in your root crate's `Cargo.toml`: +//! ```toml +//! [dependencies] +//! getrandom = { version = "0.2", features = ["js"] } +//! ``` +//! +//! ## Early boot +//! +//! Sometimes, early in the boot process, the OS has not collected enough +//! entropy to securely seed its RNG. This is especially common on virtual +//! machines, where standard "random" events are hard to come by. +//! +//! Some operating system interfaces always block until the RNG is securely +//! seeded. This can take anywhere from a few seconds to more than a minute. +//! A few (Linux, NetBSD and Solaris) offer a choice between blocking and +//! getting an error; in these cases, we always choose to block. +//! +//! On Linux (when the `getrandom` system call is not available), reading from +//! `/dev/urandom` never blocks, even when the OS hasn't collected enough +//! entropy yet. To avoid returning low-entropy bytes, we first poll +//! `/dev/random` and only switch to `/dev/urandom` once this has succeeded. +//! +//! ## Error handling +//! +//! We always choose failure over returning insecure "random" bytes. In general, +//! on supported platforms, failure is highly unlikely, though not impossible. +//! If an error does occur, then it is likely that it will occur on every call to +//! `getrandom`, hence after the first successful call one can be reasonably +//! confident that no errors will occur. +//! +//! [1]: http://man7.org/linux/man-pages/man2/getrandom.2.html +//! [2]: http://man7.org/linux/man-pages/man4/urandom.4.html +//! [3]: https://www.unix.com/man-page/mojave/2/getentropy/ +//! [4]: https://www.unix.com/man-page/mojave/4/random/ +//! [5]: https://www.freebsd.org/cgi/man.cgi?query=getrandom&manpath=FreeBSD+12.0-stable +//! [6]: https://www.freebsd.org/cgi/man.cgi?query=random&sektion=4 +//! [7]: https://man.openbsd.org/getentropy.2 +//! [8]: https://man.netbsd.org/sysctl.7 +//! [9]: https://leaf.dragonflybsd.org/cgi/web-man?command=getrandom +//! [10]: https://leaf.dragonflybsd.org/cgi/web-man?command=random§ion=4 +//! [11]: https://docs.oracle.com/cd/E88353_01/html/E37841/getrandom-2.html +//! [12]: https://docs.oracle.com/cd/E86824_01/html/E54777/random-7d.html +//! +//! [`BCryptGenRandom`]: https://docs.microsoft.com/en-us/windows/win32/api/bcrypt/nf-bcrypt-bcryptgenrandom +//! [`Crypto.getRandomValues`]: https://www.w3.org/TR/WebCryptoAPI/#Crypto-method-getRandomValues +//! [`RDRAND`]: https://software.intel.com/en-us/articles/intel-digital-random-number-generator-drng-software-implementation-guide +//! [`SecRandomCopyBytes`]: https://developer.apple.com/documentation/security/1399291-secrandomcopybytes?language=objc +//! [`cprng_draw`]: https://fuchsia.dev/fuchsia-src/zircon/syscalls/cprng_draw +//! [`crypto.randomBytes`]: https://nodejs.org/api/crypto.html#crypto_crypto_randombytes_size_callback +//! [`esp_fill_random`]: https://docs.espressif.com/projects/esp-idf/en/latest/esp32/api-reference/system/random.html#_CPPv415esp_fill_randomPv6size_t +//! [`random_get`]: https://github.com/WebAssembly/WASI/blob/main/phases/snapshot/docs.md#-random_getbuf-pointeru8-buf_len-size---errno +//! [WebAssembly support]: #webassembly-support + +#![doc( + html_logo_url = "https://www.rust-lang.org/logos/rust-logo-128x128-blk.png", + html_favicon_url = "https://www.rust-lang.org/favicon.ico", + html_root_url = "https://docs.rs/getrandom/0.2.6" +)] +#![no_std] +#![warn(rust_2018_idioms, unused_lifetimes, missing_docs)] +#![cfg_attr(docsrs, feature(doc_cfg))] + +#[macro_use] +extern crate cfg_if; + +mod error; +mod util; +// To prevent a breaking change when targets are added, we always export the +// register_custom_getrandom macro, so old Custom RNG crates continue to build. +#[cfg(feature = "custom")] +mod custom; +#[cfg(feature = "std")] +mod error_impls; + +pub use crate::error::Error; + +// System-specific implementations. +// +// These should all provide getrandom_inner with the same signature as getrandom. +cfg_if! { + if #[cfg(any(target_os = "emscripten", target_os = "haiku", + target_os = "redox"))] { + mod util_libc; + #[path = "use_file.rs"] mod imp; + } else if #[cfg(any(target_os = "android", target_os = "linux"))] { + mod util_libc; + mod use_file; + #[path = "linux_android.rs"] mod imp; + } else if #[cfg(any(target_os = "illumos", target_os = "solaris"))] { + mod util_libc; + mod use_file; + #[path = "solaris_illumos.rs"] mod imp; + } else if #[cfg(any(target_os = "freebsd", target_os = "netbsd"))] { + mod util_libc; + #[path = "bsd_arandom.rs"] mod imp; + } else if #[cfg(target_os = "dragonfly")] { + mod util_libc; + mod use_file; + #[path = "dragonfly.rs"] mod imp; + } else if #[cfg(target_os = "fuchsia")] { + #[path = "fuchsia.rs"] mod imp; + } else if #[cfg(target_os = "ios")] { + #[path = "ios.rs"] mod imp; + } else if #[cfg(target_os = "macos")] { + mod util_libc; + mod use_file; + #[path = "macos.rs"] mod imp; + } else if #[cfg(target_os = "openbsd")] { + mod util_libc; + #[path = "openbsd.rs"] mod imp; + } else if #[cfg(target_os = "wasi")] { + #[path = "wasi.rs"] mod imp; + } else if #[cfg(all(target_arch = "x86_64", target_os = "hermit"))] { + #[path = "rdrand.rs"] mod imp; + } else if #[cfg(target_os = "vxworks")] { + mod util_libc; + #[path = "vxworks.rs"] mod imp; + } else if #[cfg(target_os = "solid_asp3")] { + #[path = "solid.rs"] mod imp; + } else if #[cfg(target_os = "espidf")] { + #[path = "espidf.rs"] mod imp; + } else if #[cfg(windows)] { + #[path = "windows.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", + any(target_arch = "x86_64", target_arch = "x86")))] { + #[path = "rdrand.rs"] mod imp; + } else if #[cfg(all(feature = "js", + target_arch = "wasm32", target_os = "unknown"))] { + #[path = "js.rs"] mod imp; + } else if #[cfg(all(target_os = "horizon", target_arch = "arm"))] { + // We check for target_arch = "arm" because the Nintendo Switch also + // uses Horizon OS (it is aarch64). + mod util_libc; + #[path = "3ds.rs"] mod imp; + } else if #[cfg(feature = "custom")] { + use custom as imp; + } else if #[cfg(all(target_arch = "wasm32", target_os = "unknown"))] { + compile_error!("the wasm32-unknown-unknown target is not supported by \ + default, you may need to enable the \"js\" feature. \ + For more information see: \ + https://docs.rs/getrandom/#webassembly-support"); + } else { + compile_error!("target is not supported, for more information see: \ + https://docs.rs/getrandom/#unsupported-targets"); + } +} + +/// Fill `dest` with random bytes from the system's preferred random number +/// source. +/// +/// This function returns an error on any failure, including partial reads. We +/// make no guarantees regarding the contents of `dest` on error. If `dest` is +/// empty, `getrandom` immediately returns success, making no calls to the +/// underlying operating system. +/// +/// Blocking is possible, at least during early boot; see module documentation. +/// +/// In general, `getrandom` will be fast enough for interactive usage, though +/// significantly slower than a user-space CSPRNG; for the latter consider +/// [`rand::thread_rng`](https://docs.rs/rand/*/rand/fn.thread_rng.html). +pub fn getrandom(dest: &mut [u8]) -> Result<(), Error> { + if dest.is_empty() { + return Ok(()); + } + imp::getrandom_inner(dest) +} |