Merge pull request #217 from dnaka91/root-certs-feature-flags

Enable root cert providers through feature flags

CHANGELOG.md

@@ -1,3 +1,14 @@
+# 0.15.0 (unreleased)
+
+- Allow selecting the method of loading root certificates if `rustls` is used as TLS implementation.
+  - Two new feature flags `rustls-tls-native-roots` and `rustls-tls-webpki-roots` have been added
+    that activate the respective method to load certificates.
+  - The `rustls-tls` flag was removed to raise awareness of this change. Otherwise, compilation
+    would have continue to work and potential errors (due to different or missing certificates)
+    only occurred at runtime.
+  - The new feature flags are additive. If both are enabled, both methods will be used to add
+    certificates to the TLS configuration.
+
 # 0.14.0
 
 - Use `rustls-native-certs` instead of `webpki-root` when `rustls-tls` feature is enabled.

Cargo.toml

@@ -19,7 +19,8 @@ all-features = true
 default = []
 native-tls = ["native-tls-crate"]
 native-tls-vendored = ["native-tls", "native-tls-crate/vendored"]
-rustls-tls = ["rustls", "webpki", "rustls-native-certs"]
+rustls-tls-native-roots = ["rustls", "webpki", "rustls-native-certs"]
+rustls-tls-webpki-roots = ["rustls", "webpki", "webpki-roots"]
 
 [dependencies]
 base64 = "0.13.0"
@@ -43,13 +44,17 @@ version = "0.2.3"
 optional = true
 version = "0.19.0"
 
+[dependencies.rustls-native-certs]
+optional = true
+version = "0.5.0"
+
 [dependencies.webpki]
 optional = true
 version = "0.21"
 
-[dependencies.rustls-native-certs]
+[dependencies.webpki-roots]
 optional = true
-version = "0.5.0"
+version = "0.21"
 
 [dev-dependencies]
 criterion = "0.3.4"

src/client.rs

@@ -50,7 +50,10 @@ mod encryption {
     }
 }
 
-#[cfg(all(feature = "rustls-tls", not(feature = "native-tls")))]
+#[cfg(all(
+    any(feature = "rustls-tls-native-roots", feature = "rustls-tls-webpki-roots"),
+    not(feature = "native-tls")
+))]
 mod encryption {
     use rustls::ClientConfig;
     pub use rustls::{ClientSession, StreamOwned};
@@ -71,12 +74,21 @@ mod encryption {
             Mode::Plain => Ok(StreamSwitcher::Plain(stream)),
             Mode::Tls => {
                 let config = {
+                    #[allow(unused_mut)]
                     let mut config = ClientConfig::new();
-                    config.root_store =
-                        rustls_native_certs::load_native_certs().map_err(|(_, err)| err)?;
+                    #[cfg(feature = "rustls-tls-native-roots")]
+                    {
+                        config.root_store =
+                            rustls_native_certs::load_native_certs().map_err(|(_, err)| err)?;
+                    }
+                    #[cfg(feature = "rustls-tls-webpki-roots")]
+                    {
+                        config.root_store.add_server_trust_anchors(&webpki_roots::TLS_SERVER_ROOTS);
+                    }
 
                     Arc::new(config)
                 };
+
                 let domain = DNSNameRef::try_from_ascii_str(domain).map_err(TlsError::Dns)?;
                 let client = ClientSession::new(&config, domain);
                 let stream = StreamOwned::new(client, stream);
@@ -87,7 +99,11 @@ mod encryption {
     }
 }
 
-#[cfg(not(any(feature = "native-tls", feature = "rustls-tls")))]
+#[cfg(not(any(
+    feature = "native-tls",
+    feature = "rustls-tls-native-roots",
+    feature = "rustls-tls-webpki-roots"
+)))]
 mod encryption {
     use std::net::TcpStream;
 

src/error.rs

@@ -253,11 +253,11 @@ pub enum TlsError {
     #[error("native-tls error: {0}")]
     Native(#[from] native_tls_crate::Error),
     /// Rustls error.
-    #[cfg(feature = "rustls-tls")]
+    #[cfg(any(feature = "rustls-tls-native-roots", feature = "rustls-tls-webpki-roots"))]
     #[error("rustls error: {0}")]
     Rustls(#[from] rustls::TLSError),
     /// DNS name resolution error.
-    #[cfg(feature = "rustls-tls")]
+    #[cfg(any(feature = "rustls-tls-native-roots", feature = "rustls-tls-webpki-roots"))]
     #[error("Invalid DNS name: {0}")]
     Dns(#[from] webpki::InvalidDNSNameError),
 }

src/stream.rs

@@ -10,7 +10,7 @@ use std::net::TcpStream;
 
 #[cfg(feature = "native-tls")]
 use native_tls_crate::TlsStream;
-#[cfg(feature = "rustls-tls")]
+#[cfg(any(feature = "rustls-tls-native-roots", feature = "rustls-tls-webpki-roots"))]
 use rustls::StreamOwned;
 
 /// Stream mode, either plain TCP or TLS.
@@ -41,7 +41,7 @@ impl<S: Read + Write + NoDelay> NoDelay for TlsStream<S> {
     }
 }
 
-#[cfg(feature = "rustls-tls")]
+#[cfg(any(feature = "rustls-tls-native-roots", feature = "rustls-tls-webpki-roots"))]
 impl<S: rustls::Session, T: Read + Write + NoDelay> NoDelay for StreamOwned<S, T> {
     fn set_nodelay(&mut self, nodelay: bool) -> IoResult<()> {
         self.sock.set_nodelay(nodelay)

tests/connection_reset.rs

@@ -1,6 +1,10 @@
 //! Verifies that the server returns a `ConnectionClosed` error when the connection
 //! is closed from the server's point of view and drop the underlying tcp socket.
-#![cfg(any(feature = "native-tls", feature = "rustls-tls"))]
+#![cfg(any(
+    feature = "native-tls",
+    feature = "rustls-tls-native-roots",
+    feature = "rustls-tls-webpki-roots"
+))]
 
 use std::{
     net::{TcpListener, TcpStream},
@@ -15,7 +19,10 @@ use url::Url;
 
 #[cfg(feature = "native-tls")]
 type Sock = WebSocket<Stream<TcpStream, native_tls_crate::TlsStream<TcpStream>>>;
-#[cfg(all(feature = "rustls-tls", not(feature = "native-tls")))]
+#[cfg(all(
+    any(feature = "rustls-tls-native-roots", feature = "rustls-tls-webpki-roots"),
+    not(feature = "native-tls")
+))]
 type Sock = WebSocket<Stream<TcpStream, rustls::StreamOwned<rustls::ClientSession, TcpStream>>>;
 
 fn do_test<CT, ST>(port: u16, client_task: CT, server_task: ST)