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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 09:22:09 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 09:22:09 +0000 |
commit | 43a97878ce14b72f0981164f87f2e35e14151312 (patch) | |
tree | 620249daf56c0258faa40cbdcf9cfba06de2a846 /third_party/rust/getrandom/src/js.rs | |
parent | Initial commit. (diff) | |
download | firefox-upstream.tar.xz firefox-upstream.zip |
Adding upstream version 110.0.1.upstream/110.0.1upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'third_party/rust/getrandom/src/js.rs')
-rw-r--r-- | third_party/rust/getrandom/src/js.rs | 144 |
1 files changed, 144 insertions, 0 deletions
diff --git a/third_party/rust/getrandom/src/js.rs b/third_party/rust/getrandom/src/js.rs new file mode 100644 index 0000000000..574c4dc326 --- /dev/null +++ b/third_party/rust/getrandom/src/js.rs @@ -0,0 +1,144 @@ +// 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. +use crate::Error; + +extern crate std; +use std::thread_local; + +use js_sys::{global, Function, Uint8Array}; +use wasm_bindgen::{prelude::wasm_bindgen, JsCast, JsValue}; + +// Size of our temporary Uint8Array buffer used with WebCrypto methods +// Maximum is 65536 bytes see https://developer.mozilla.org/en-US/docs/Web/API/Crypto/getRandomValues +const WEB_CRYPTO_BUFFER_SIZE: usize = 256; + +enum RngSource { + Node(NodeCrypto), + Web(WebCrypto, Uint8Array), +} + +// JsValues are always per-thread, so we initialize RngSource for each thread. +// See: https://github.com/rustwasm/wasm-bindgen/pull/955 +thread_local!( + static RNG_SOURCE: Result<RngSource, Error> = getrandom_init(); +); + +pub(crate) fn getrandom_inner(dest: &mut [u8]) -> Result<(), Error> { + RNG_SOURCE.with(|result| { + let source = result.as_ref().map_err(|&e| e)?; + + match source { + RngSource::Node(n) => { + if n.random_fill_sync(dest).is_err() { + return Err(Error::NODE_RANDOM_FILL_SYNC); + } + } + RngSource::Web(crypto, buf) => { + // getRandomValues does not work with all types of WASM memory, + // so we initially write to browser memory to avoid exceptions. + for chunk in dest.chunks_mut(WEB_CRYPTO_BUFFER_SIZE) { + // The chunk can be smaller than buf's length, so we call to + // JS to create a smaller view of buf without allocation. + let sub_buf = buf.subarray(0, chunk.len() as u32); + + if crypto.get_random_values(&sub_buf).is_err() { + return Err(Error::WEB_GET_RANDOM_VALUES); + } + sub_buf.copy_to(chunk); + } + } + }; + Ok(()) + }) +} + +fn getrandom_init() -> Result<RngSource, Error> { + let global: Global = global().unchecked_into(); + + // Get the Web Crypto interface if we are in a browser, Web Worker, Deno, + // or another environment that supports the Web Cryptography API. This + // also allows for user-provided polyfills in unsupported environments. + let crypto = match global.crypto() { + // Standard Web Crypto interface + c if c.is_object() => c, + // Node.js CommonJS Crypto module + _ if is_node(&global) => { + // If module.require isn't a valid function, we are in an ES module. + match Module::require_fn().and_then(JsCast::dyn_into::<Function>) { + Ok(require_fn) => match require_fn.call1(&global, &JsValue::from_str("crypto")) { + Ok(n) => return Ok(RngSource::Node(n.unchecked_into())), + Err(_) => return Err(Error::NODE_CRYPTO), + }, + Err(_) => return Err(Error::NODE_ES_MODULE), + } + } + // IE 11 Workaround + _ => match global.ms_crypto() { + c if c.is_object() => c, + _ => return Err(Error::WEB_CRYPTO), + }, + }; + + let buf = Uint8Array::new_with_length(WEB_CRYPTO_BUFFER_SIZE as u32); + Ok(RngSource::Web(crypto, buf)) +} + +// Taken from https://www.npmjs.com/package/browser-or-node +fn is_node(global: &Global) -> bool { + let process = global.process(); + if process.is_object() { + let versions = process.versions(); + if versions.is_object() { + return versions.node().is_string(); + } + } + false +} + +#[wasm_bindgen] +extern "C" { + // Return type of js_sys::global() + type Global; + + // Web Crypto API: Crypto interface (https://www.w3.org/TR/WebCryptoAPI/) + type WebCrypto; + // Getters for the WebCrypto API + #[wasm_bindgen(method, getter)] + fn crypto(this: &Global) -> WebCrypto; + #[wasm_bindgen(method, getter, js_name = msCrypto)] + fn ms_crypto(this: &Global) -> WebCrypto; + // Crypto.getRandomValues() + #[wasm_bindgen(method, js_name = getRandomValues, catch)] + fn get_random_values(this: &WebCrypto, buf: &Uint8Array) -> Result<(), JsValue>; + + // Node JS crypto module (https://nodejs.org/api/crypto.html) + type NodeCrypto; + // crypto.randomFillSync() + #[wasm_bindgen(method, js_name = randomFillSync, catch)] + fn random_fill_sync(this: &NodeCrypto, buf: &mut [u8]) -> Result<(), JsValue>; + + // Ideally, we would just use `fn require(s: &str)` here. However, doing + // this causes a Webpack warning. So we instead return the function itself + // and manually invoke it using call1. This also lets us to check that the + // function actually exists, allowing for better error messages. See: + // https://github.com/rust-random/getrandom/issues/224 + // https://github.com/rust-random/getrandom/issues/256 + type Module; + #[wasm_bindgen(getter, static_method_of = Module, js_class = module, js_name = require, catch)] + fn require_fn() -> Result<JsValue, JsValue>; + + // Node JS process Object (https://nodejs.org/api/process.html) + #[wasm_bindgen(method, getter)] + fn process(this: &Global) -> Process; + type Process; + #[wasm_bindgen(method, getter)] + fn versions(this: &Process) -> Versions; + type Versions; + #[wasm_bindgen(method, getter)] + fn node(this: &Versions) -> JsValue; +} |