aquatic_common: add feature gated fn create_rustls_config

aquatic_common/src/rustls_config.rs

@@ -0,0 +1,35 @@
+use std::{fs::File, io::BufReader, path::Path};
+
+pub type RustlsConfig = rustls::ServerConfig;
+
+pub fn create_rustls_config(
+    tls_certificate_path: &Path,
+    tls_private_key_path: &Path,
+) -> anyhow::Result<RustlsConfig> {
+    let certs = {
+        let f = File::open(tls_certificate_path)?;
+        let mut f = BufReader::new(f);
+
+        rustls_pemfile::certs(&mut f)?
+            .into_iter()
+            .map(|bytes| rustls::Certificate(bytes))
+            .collect()
+    };
+
+    let private_key = {
+        let f = File::open(tls_private_key_path)?;
+        let mut f = BufReader::new(f);
+
+        rustls_pemfile::pkcs8_private_keys(&mut f)?
+            .first()
+            .map(|bytes| rustls::PrivateKey(bytes.clone()))
+            .ok_or(anyhow::anyhow!("No private keys in file"))?
+    };
+
+    let tls_config = rustls::ServerConfig::builder()
+        .with_safe_defaults()
+        .with_no_client_auth()
+        .with_single_cert(certs, private_key)?;
+
+    Ok(tls_config)
+}