Implement manual TLS certificate loading and ServerConfig construction

- Add tls::config module with manual TLS mode support - Load PEM certificates and private keys via rustls_pemfile - Build ServerConfig with aws_lc_rs crypto provider - Restrict cipher suites per ADR-012 (4 TLS 1.2 ECDHE-AES-GCM + all TLS 1.3) - Configure protocol versions to TLS 1.2 and 1.3 only - Implement SniCertResolver for multi-domain manual mode - Unknown SNI hostname fails handshake (no default cert) - Add tempfile dev dependency for test file operations - Add 11 unit tests covering config, cipher suites, and SNI resolution
2026-06-11 11:57:24 +00:00
parent 33a448505e
commit dd748b973d
4 changed files with 339 additions and 4 deletions
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1531,6 +1531,7 @@ dependencies = [
 "rustls-pki-types",
 "serde",
 "signal-hook",
+ "tempfile",
 "thiserror 2.0.18",
 "tokio",
 "tokio-rustls",
@@ -1907,15 +1908,15 @@ dependencies = [

 [[package]]
 name = "tempfile"
-version = "3.27.0"
+version = "3.20.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "32497e9a4c7b38532efcdebeef879707aa9f794296a4f0244f6f69e9bc8574bd"
+checksum = "e8a64e3985349f2441a1a9ef0b853f869006c3855f2cda6862a94d26ebb9d6a1"
 dependencies = [
 "fastrand",
 "getrandom 0.3.4",
 "once_cell",
 "rustix",
- "windows-sys 0.61.2",
+ "windows-sys 0.52.0",
 ]

 [[package]]
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -35,3 +35,4 @@ thiserror = "=2.0.18"
 [dev-dependencies]
 rcgen = "=0.13"
 reqwest = { version = "=0.12", features = ["json"] }
+tempfile = "=3.20"
--- a/src/tls/config.rs
+++ b/src/tls/config.rs
@@ -0,0 +1,332 @@
+use std::collections::HashMap;
+use std::fs::File;
+use std::io::BufReader;
+use std::sync::Arc;
+
+use anyhow::{bail, Context, Result};
+use rustls::crypto::aws_lc_rs;
+use rustls::crypto::aws_lc_rs::cipher_suite::{
+    TLS13_AES_128_GCM_SHA256, TLS13_AES_256_GCM_SHA384, TLS13_CHACHA20_POLY1305_SHA256,
+    TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256, TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,
+    TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256, TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,
+};
+use rustls::crypto::CryptoProvider;
+use rustls::pki_types::{CertificateDer, PrivateKeyDer};
+use rustls::server::{ClientHello, ResolvesServerCert};
+use rustls::sign::CertifiedKey;
+use rustls::{ServerConfig, SupportedCipherSuite};
+use rustls_pemfile;
+
+static RESTRICTED_CIPHER_SUITES: &[SupportedCipherSuite] = &[
+    TLS13_AES_256_GCM_SHA384,
+    TLS13_AES_128_GCM_SHA256,
+    TLS13_CHACHA20_POLY1305_SHA256,
+    TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,
+    TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,
+    TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,
+    TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,
+];
+
+fn crypto_provider() -> Arc<CryptoProvider> {
+    let mut provider = aws_lc_rs::default_provider();
+    provider.cipher_suites = RESTRICTED_CIPHER_SUITES.to_vec();
+    Arc::new(provider)
+}
+
+pub fn load_certs(path: &str) -> Result<Vec<CertificateDer<'static>>> {
+    let file =
+        File::open(path).with_context(|| format!("failed to open certificate file: {path}"))?;
+    let mut reader = BufReader::new(file);
+    let certs: Vec<CertificateDer<'static>> = rustls_pemfile::certs(&mut reader)
+        .collect::<Result<Vec<_>, _>>()
+        .with_context(|| format!("failed to parse certificate file: {path}"))?;
+    if certs.is_empty() {
+        bail!("no certificates found in {path}");
+    }
+    Ok(certs)
+}
+
+pub fn load_private_key(path: &str) -> Result<PrivateKeyDer<'static>> {
+    let file =
+        File::open(path).with_context(|| format!("failed to open private key file: {path}"))?;
+    let mut reader = BufReader::new(file);
+    let key = rustls_pemfile::private_key(&mut reader)
+        .with_context(|| format!("failed to parse private key file: {path}"))?;
+    key.context(format!("no private key found in {path}"))
+}
+
+pub fn build_manual_server_config(cert_path: &str, key_path: &str) -> Result<ServerConfig> {
+    let certs = load_certs(cert_path)?;
+    let key = load_private_key(key_path)?;
+
+    let provider = crypto_provider();
+    let config = ServerConfig::builder_with_provider(provider)
+        .with_protocol_versions(&[&rustls::version::TLS12, &rustls::version::TLS13])
+        .with_context(|| "failed to set protocol versions")?
+        .with_no_client_auth()
+        .with_single_cert(certs, key)
+        .with_context(|| "failed to configure certificate/key pair")?;
+
+    Ok(config)
+}
+
+pub fn build_multi_domain_server_config(
+    domain_certs: &HashMap<String, (Vec<CertificateDer<'static>>, PrivateKeyDer<'static>)>,
+) -> Result<ServerConfig> {
+    let provider = crypto_provider();
+
+    let mut resolver = SniCertResolver::new();
+    for (domain, (certs, key)) in domain_certs {
+        let certified_key = CertifiedKey::from_der(certs.clone(), key.clone_key(), &provider)
+            .with_context(|| format!("failed to load cert/key for domain {domain}"))?;
+        resolver.add(domain, Arc::new(certified_key));
+    }
+
+    let config = ServerConfig::builder_with_provider(provider)
+        .with_protocol_versions(&[&rustls::version::TLS12, &rustls::version::TLS13])
+        .with_context(|| "failed to set protocol versions")?
+        .with_no_client_auth()
+        .with_cert_resolver(Arc::new(resolver));
+
+    Ok(config)
+}
+
+#[derive(Debug)]
+struct SniCertResolver {
+    entries: HashMap<String, Arc<CertifiedKey>>,
+}
+
+impl SniCertResolver {
+    fn new() -> Self {
+        Self {
+            entries: HashMap::new(),
+        }
+    }
+
+    fn add(&mut self, domain: &str, certified_key: Arc<CertifiedKey>) {
+        self.entries.insert(domain.to_lowercase(), certified_key);
+    }
+}
+
+impl ResolvesServerCert for SniCertResolver {
+    fn resolve(&self, client_hello: ClientHello<'_>) -> Option<Arc<CertifiedKey>> {
+        let server_name = client_hello.server_name()?;
+        self.entries.get(&server_name.to_lowercase()).cloned()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use rcgen::{CertificateParams, IsCa, KeyPair};
+    use rustls::pki_types::PrivatePkcs8KeyDer;
+
+    fn generate_test_cert(domain: &str) -> (Vec<CertificateDer<'static>>, PrivateKeyDer<'static>) {
+        let mut params =
+            CertificateParams::new(vec![domain.to_string()]).expect("failed to create cert params");
+        params.is_ca = IsCa::NoCa;
+        let key_pair = KeyPair::generate().expect("failed to generate key pair");
+        let cert = params
+            .self_signed(&key_pair)
+            .expect("failed to self-sign cert");
+        let cert_der = cert.der().clone();
+        let key_der = PrivateKeyDer::from(PrivatePkcs8KeyDer::from(key_pair.serialize_der()));
+        (vec![cert_der], key_der)
+    }
+
+    fn generate_test_cert_pem(domain: &str) -> (String, String) {
+        let mut params =
+            CertificateParams::new(vec![domain.to_string()]).expect("failed to create cert params");
+        params.is_ca = IsCa::NoCa;
+        let key_pair = KeyPair::generate().expect("failed to generate key pair");
+        let cert = params
+            .self_signed(&key_pair)
+            .expect("failed to self-sign cert");
+        let cert_pem = cert.pem();
+        let key_pem = key_pair.serialize_pem();
+        (cert_pem, key_pem)
+    }
+
+    #[test]
+    fn test_build_manual_server_config() {
+        let (certs, key) = generate_test_cert("test.example.com");
+        let provider = crypto_provider();
+        let config = ServerConfig::builder_with_provider(provider)
+            .with_protocol_versions(&[&rustls::version::TLS12, &rustls::version::TLS13])
+            .unwrap()
+            .with_no_client_auth()
+            .with_single_cert(certs, key)
+            .unwrap();
+        assert!(!config.ignore_client_order);
+    }
+
+    #[test]
+    fn test_load_certs_from_pem() {
+        let dir = tempfile::tempdir().unwrap();
+        let (cert_pem, _) = generate_test_cert_pem("test.example.com");
+        let cert_path = dir.path().join("cert.pem");
+        std::fs::write(&cert_path, cert_pem).unwrap();
+        let certs = load_certs(cert_path.to_str().unwrap()).unwrap();
+        assert_eq!(certs.len(), 1);
+    }
+
+    #[test]
+    fn test_load_private_key_from_pem() {
+        let dir = tempfile::tempdir().unwrap();
+        let (_, key_pem) = generate_test_cert_pem("test.example.com");
+        let key_path = dir.path().join("key.pem");
+        std::fs::write(&key_path, key_pem).unwrap();
+        let key = load_private_key(key_path.to_str().unwrap()).unwrap();
+        assert!(matches!(key, PrivateKeyDer::Pkcs8(_)));
+    }
+
+    #[test]
+    fn test_build_manual_server_config_from_files() {
+        let dir = tempfile::tempdir().unwrap();
+        let (cert_pem, key_pem) = generate_test_cert_pem("test.example.com");
+        let cert_path = dir.path().join("cert.pem");
+        let key_path = dir.path().join("key.pem");
+        std::fs::write(&cert_path, &cert_pem).unwrap();
+        std::fs::write(&key_path, &key_pem).unwrap();
+        let config =
+            build_manual_server_config(cert_path.to_str().unwrap(), key_path.to_str().unwrap())
+                .unwrap();
+        assert!(!config.ignore_client_order);
+    }
+
+    #[test]
+    fn test_cipher_suite_restriction() {
+        let provider = crypto_provider();
+        assert_eq!(provider.cipher_suites.len(), 7);
+
+        let has_tls13_aes_256 = provider.cipher_suites.iter().any(|cs| {
+            format!("{cs:?}").contains("AES_256_GCM_SHA384") && format!("{cs:?}").contains("TLS13")
+        });
+        let has_tls13_aes_128 = provider.cipher_suites.iter().any(|cs| {
+            format!("{cs:?}").contains("AES_128_GCM_SHA256") && format!("{cs:?}").contains("TLS13")
+        });
+        let has_tls13_chacha = provider
+            .cipher_suites
+            .iter()
+            .any(|cs| format!("{cs:?}").contains("CHACHA20_POLY1305_SHA256"));
+        let has_ecdsa_aes256 = provider
+            .cipher_suites
+            .iter()
+            .any(|cs| format!("{cs:?}").contains("ECDHE_ECDSA_WITH_AES_256_GCM_SHA384"));
+        let has_ecdsa_aes128 = provider
+            .cipher_suites
+            .iter()
+            .any(|cs| format!("{cs:?}").contains("ECDHE_ECDSA_WITH_AES_128_GCM_SHA256"));
+        let has_rsa_aes256 = provider
+            .cipher_suites
+            .iter()
+            .any(|cs| format!("{cs:?}").contains("ECDHE_RSA_WITH_AES_256_GCM_SHA384"));
+        let has_rsa_aes128 = provider
+            .cipher_suites
+            .iter()
+            .any(|cs| format!("{cs:?}").contains("ECDHE_RSA_WITH_AES_128_GCM_SHA256"));
+
+        assert!(has_tls13_aes_256);
+        assert!(has_tls13_aes_128);
+        assert!(has_tls13_chacha);
+        assert!(has_ecdsa_aes256);
+        assert!(has_ecdsa_aes128);
+        assert!(has_rsa_aes256);
+        assert!(has_rsa_aes128);
+    }
+
+    #[test]
+    fn test_no_chacha20_for_tls12() {
+        let provider = crypto_provider();
+        let tls12_chacha = provider.cipher_suites.iter().any(|cs| {
+            let dbg = format!("{cs:?}");
+            dbg.contains("ECDHE") && dbg.contains("CHACHA20")
+        });
+        assert!(
+            !tls12_chacha,
+            "TLS 1.2 ChaCha20 suites should not be present"
+        );
+    }
+
+    #[test]
+    fn test_protocol_versions_configured() {
+        let (certs, key) = generate_test_cert("test.example.com");
+        let provider = crypto_provider();
+        let _config = ServerConfig::builder_with_provider(provider)
+            .with_protocol_versions(&[&rustls::version::TLS12, &rustls::version::TLS13])
+            .unwrap()
+            .with_no_client_auth()
+            .with_single_cert(certs, key)
+            .unwrap();
+    }
+
+    #[test]
+    fn test_sni_resolver_known_domain() {
+        let (certs, key) = generate_test_cert("example.com");
+        let provider = crypto_provider();
+        let certified_key = CertifiedKey::from_der(certs, key, &provider).unwrap();
+        let mut resolver = SniCertResolver::new();
+        resolver.add("example.com", Arc::new(certified_key));
+
+        let resolved = resolver.entries.get("example.com");
+        assert!(resolved.is_some());
+    }
+
+    #[test]
+    fn test_sni_resolver_unknown_domain_returns_none() {
+        let (certs, key) = generate_test_cert("example.com");
+        let provider = crypto_provider();
+        let certified_key = CertifiedKey::from_der(certs, key, &provider).unwrap();
+        let mut resolver = SniCertResolver::new();
+        resolver.add("example.com", Arc::new(certified_key));
+
+        let resolved = resolver.entries.get("unknown.com");
+        assert!(resolved.is_none());
+    }
+
+    #[test]
+    fn test_sni_resolver_normalizes_domain_to_lowercase() {
+        let (certs, key) = generate_test_cert("Example.COM");
+        let provider = crypto_provider();
+        let certified_key = CertifiedKey::from_der(certs, key, &provider).unwrap();
+        let mut resolver = SniCertResolver::new();
+        resolver.add("Example.COM", Arc::new(certified_key));
+
+        assert!(resolver.entries.contains_key("example.com"));
+        assert!(!resolver.entries.contains_key("Example.COM"));
+    }
+
+    #[test]
+    fn test_build_multi_domain_server_config() {
+        let (certs1, key1) = generate_test_cert("site1.example.com");
+        let (certs2, key2) = generate_test_cert("site2.example.com");
+
+        let mut domain_certs = HashMap::new();
+        domain_certs.insert("site1.example.com".to_string(), (certs1, key1));
+        domain_certs.insert("site2.example.com".to_string(), (certs2, key2));
+
+        let config = build_multi_domain_server_config(&domain_certs).unwrap();
+        assert!(!config.ignore_client_order);
+    }
+
+    #[test]
+    fn test_load_certs_empty_file() {
+        let dir = tempfile::tempdir().unwrap();
+        let cert_path = dir.path().join("empty.pem");
+        std::fs::write(&cert_path, "").unwrap();
+        let result = load_certs(cert_path.to_str().unwrap());
+        assert!(result.is_err());
+    }
+
+    #[test]
+    fn test_load_certs_nonexistent_file() {
+        let result = load_certs("/nonexistent/path/cert.pem");
+        assert!(result.is_err());
+    }
+
+    #[test]
+    fn test_load_private_key_nonexistent_file() {
+        let result = load_private_key("/nonexistent/path/key.pem");
+        assert!(result.is_err());
+    }
+}
--- a/src/tls/mod.rs
+++ b/src/tls/mod.rs
@@ -1,2 +1,3 @@
 pub mod acceptor;
+pub mod config;
 pub mod redirect;