feat(node): add a web crypto provider for node

Author: Nicola Dardanis

Cargo.toml

@@ -12,6 +12,7 @@ members = [
     "mls-rs-crypto-rustcrypto",
     "mls-rs-crypto-awslc",
     "mls-rs-crypto-webcrypto",
+    "mls-rs-crypto-webnodecrypto",
     "mls-rs-crypto-hpke",
     "mls-rs-provider-sqlite",
     "mls-rs-codec",
@@ -28,6 +29,7 @@ default-members = [
     "mls-rs-crypto-hpke",
     "mls-rs-crypto-openssl",
     "mls-rs-crypto-rustcrypto",
+    "mls-rs-crypto-webnodecrypto",
     "mls-rs-crypto-awslc",
     "mls-rs-crypto-webcrypto",
     "mls-rs-provider-sqlite",

mls-rs-crypto-webcrypto/Cargo.toml

@@ -8,7 +8,13 @@ repository = "https://github.com/awslabs/mls-rs"
 keywords = ["mls", "mls-rs"]
 license = "Apache-2.0 OR MIT"
 
+[features]
+web = []
+node = []
+default = ["web"]
+
 [dependencies]
+cfg-if = "1.0.0"
 mls-rs-core = { path = "../mls-rs-core", default-features = false, features = ["std"], version = "0.19.0" }
 mls-rs-crypto-hpke = { path = "../mls-rs-crypto-hpke", default-features = false, features = ["std"], version = "0.10.0" }
 mls-rs-crypto-traits = { path = "../mls-rs-crypto-traits", default-features = false, features = ["std"], version = "0.11.0" }

mls-rs-crypto-webcrypto/js/node-crypto.js

@@ -0,0 +1,5 @@
+const crypto = require("node:crypto");
+
+module.exports.node_crypto = function() {
+    return crypto;
+};

mls-rs-crypto-webcrypto/src/lib.rs

@@ -26,8 +26,10 @@ use mls_rs_crypto_hpke::{
 use mls_rs_crypto_traits::{AeadType, KdfType, KemId};
 
 use wasm_bindgen::JsValue;
+use wasm_bindgen::prelude::*;
 use web_sys::SubtleCrypto;
 use zeroize::Zeroizing;
+use cfg_if::cfg_if;
 
 use crate::{
     aead::Aead,
@@ -61,14 +63,33 @@ impl From<JsValue> for CryptoError {
     }
 }
 
-#[inline]
-pub(crate) fn get_crypto() -> Result<SubtleCrypto, CryptoError> {
-    Ok(web_sys::window()
-        .ok_or(CryptoError::WindowNotFound)?
-        .crypto()?
-        .subtle())
+cfg_if! {
+    if #[cfg(feature = "web")] {
+        #[inline]
+        pub(crate) fn get_crypto() -> Result<SubtleCrypto, CryptoError> {
+            Ok(web_sys::window()
+                .ok_or(CryptoError::WindowNotFound)?
+                .crypto()?
+                .subtle())
+        }
+    } else {
+        use web_sys::Crypto;
+
+        #[wasm_bindgen(module = "/js/node-crypto.js")]
+        extern "C" {
+            #[wasm_bindgen]
+            fn node_crypto() -> Crypto;
+        }
+
+        #[inline]
+        pub(crate) fn get_crypto() -> Result<SubtleCrypto, CryptoError> {
+            Ok(node_crypto()
+                .subtle())
+        }
+    }
 }
 
+
 #[derive(Clone, Default, Debug)]
 pub struct WebCryptoProvider;