Expose and forward rustls default features

tls12 and logging are rustls features we enable by default,
as does rustls, exposing them explicitly allows users
to disable them by disabling hyper-rustls default features.

Author: g2p

Cargo.toml

@@ -10,13 +10,13 @@ homepage = "https://github.com/ctz/hyper-rustls"
 repository = "https://github.com/ctz/hyper-rustls"
 
 [dependencies]
-log = "0.4.4"
+log = { version = "0.4.4", optional = true }
 http = "0.2"
 hyper = { version = "0.14", default-features = false, features = ["client"] }
-rustls = "0.20"
+rustls = { version = "0.20", default-features = false }
 rustls-native-certs = { version = "0.6", optional = true }
 tokio = "1.0"
-tokio-rustls = "0.23"
+tokio-rustls = { version = "0.23", default-features = false }
 webpki-roots = { version = "0.22", optional = true }
 
 [dev-dependencies]
@@ -27,12 +27,14 @@ futures-util = { version = "0.3.1", default-features = false }
 rustls-pemfile = "0.2.1"
 
 [features]
-default = ["native-tokio", "http1"]
+default = ["native-tokio", "http1", "tls12", "logging"]
 http1 = ["hyper/http1"]
 http2 = ["hyper/http2"]
 webpki-tokio = ["tokio-runtime", "webpki-roots"]
 native-tokio = ["tokio-runtime", "rustls-native-certs"]
 tokio-runtime =  ["hyper/runtime"]
+tls12 = ["tokio-rustls/tls12", "rustls/tls12"]
+logging = ["log", "tokio-rustls/logging", "rustls/logging"]
 
 [[example]]
 name = "client"

src/config.rs

@@ -29,6 +29,7 @@ impl ConfigBuilderExt for ConfigBuilder<ClientConfig, WantsVerifier> {
         for cert in rustls_native_certs::load_native_certs().expect("could not load platform certs")
         {
             let cert = rustls::Certificate(cert.0);
+            #[cfg_attr(not(feature = "logging"), allow(unused_variables))]
             match roots.add(&cert) {
                 Ok(_) => valid_count += 1,
                 Err(err) => {