fix(homecore-server): provision stable HAP identity securely

v2/crates/homecore-server/src/hap.rs

@@ -11,6 +11,7 @@ use homecore::HomeCore;
 pub(crate) struct HapRuntimeConfig {
     pub bind_addr: Option<SocketAddr>,
     pub device_id: Option<String>,
+    pub setup_code: Option<String>,
     pub advertise_addr: Option<IpAddr>,
     pub hostname: String,
     pub instance_name: String,
@@ -84,7 +85,24 @@ pub(crate) async fn start(hc: &HomeCore, config: HapRuntimeConfig) -> Result<Hap
             config.hostname.clone(),
             advertise_addr,
         )?);
-        let pairings = Arc::new(PairingStore::open(&config.pairing_store)?);
+        let pairings = if config.pairing_store.exists() {
+            if config.setup_code.is_some() {
+                tracing::warn!(
+                    "ignoring --hap-setup-code because the pairing store already exists"
+                );
+            }
+            PairingStore::open(&config.pairing_store)?
+        } else {
+            let setup_code = config.setup_code.as_deref().ok_or_else(|| {
+                anyhow::anyhow!("--hap-setup-code is required when creating a HAP pairing store")
+            })?;
+            PairingStore::create(
+                &config.pairing_store,
+                homecore_hap::SetupCode::parse(setup_code)?,
+                Some(device_id.to_owned()),
+            )?
+        };
+        let pairings = Arc::new(pairings);
         let record =
             HapServiceRecord::bridge(config.instance_name.clone(), bind_addr.port(), device_id);
         let bridge = HapBridge::new(record);

v2/crates/homecore-server/src/main.rs

@@ -149,6 +149,11 @@ struct Cli {
     #[arg(long, env = "HOMECORE_HAP_DEVICE_ID")]
     hap_device_id: Option<String>,
 
+    /// HAP setup code in `XXX-XX-XXX` form. Required only when creating a
+    /// pairing store for the first time and never persisted in plaintext.
+    #[arg(long, env = "HOMECORE_HAP_SETUP_CODE", hide_env_values = true)]
+    hap_setup_code: Option<String>,
+
     /// LAN address published in the HAP mDNS record. Required when HAP is enabled.
     #[arg(long, env = "HOMECORE_HAP_ADVERTISE_ADDR")]
     hap_advertise_addr: Option<std::net::IpAddr>,
@@ -177,7 +182,7 @@ struct Cli {
 #[tokio::main]
 async fn main() -> Result<()> {
     init_tracing();
-    let cli = Cli::parse();
+    let mut cli = Cli::parse();
     let has_tokens = std::env::var("HOMECORE_TOKENS")
         .map(|value| !value.trim().is_empty())
         .unwrap_or(false);
@@ -325,6 +330,7 @@ async fn main() -> Result<()> {
         hap::HapRuntimeConfig {
             bind_addr: cli.hap_bind,
             device_id: cli.hap_device_id.clone(),
+            setup_code: cli.hap_setup_code.take(),
             advertise_addr: cli.hap_advertise_addr,
             hostname: cli.hap_hostname.clone(),
             instance_name: cli.hap_instance_name.clone(),