From 710d716686bf031783c64d2b29da21375281bf4f Mon Sep 17 00:00:00 2001
From: Kevin Wang <wy721@qq.com>
Date: Mon, 25 Nov 2024 12:56:38 +0000
Subject: [PATCH] No ca cert if kms is disabled

---
 tdxctl/src/fde_setup.rs |  6 ++----
 tdxctl/src/main.rs      | 15 ++++-----------
 tdxctl/src/tboot.rs     | 15 +++++++++++----
 3 files changed, 17 insertions(+), 19 deletions(-)

diff --git a/tdxctl/src/fde_setup.rs b/tdxctl/src/fde_setup.rs
index e7eb950..17b3283 100644
--- a/tdxctl/src/fde_setup.rs
+++ b/tdxctl/src/fde_setup.rs
@@ -16,7 +16,7 @@ use crate::{
     crypto::dh_decrypt,
     utils::{
         copy_dir_all, deserialize_json_file, extend_rtmr3, run_command, run_command_with_stdin,
-        sha256_file, AppCompose, AppKeys, HashingFile, VmConfig,
+        sha256, sha256_file, AppCompose, AppKeys, HashingFile, VmConfig,
     },
     GenAppKeysArgs, GenRaCertArgs,
 };
@@ -178,7 +178,7 @@ pub async fn cmd_setup_fde(args: SetupFdeArgs) -> Result<()> {
     let ca_cert_hash = if kms_enabled {
         sha256_file(host_shared_dir.kms_ca_cert_file())?
     } else {
-        sha256_file(host_shared_dir.tmp_ca_cert_file())?
+        sha256(b"")
     };
     let tapp_dir = args.rootfs_dir.join("tapp");
     let app_keys_file = args.work_dir.join("appkeys.json");
@@ -241,8 +241,6 @@ pub async fn cmd_setup_fde(args: SetupFdeArgs) -> Result<()> {
     } else {
         info!("KMS is not enabled, generating local app keys");
         cmd_gen_app_keys(GenAppKeysArgs {
-            ca_cert: host_shared_dir.tmp_ca_cert_file(),
-            ca_key: host_shared_dir.tmp_ca_key_file(),
             ca_level: 1,
             output: app_keys_file.clone(),
         })?;
diff --git a/tdxctl/src/main.rs b/tdxctl/src/main.rs
index d441a7d..6c2ce7e 100644
--- a/tdxctl/src/main.rs
+++ b/tdxctl/src/main.rs
@@ -120,14 +120,6 @@ struct GenCaCertArgs {
 #[derive(Parser)]
 /// Generate app keys
 struct GenAppKeysArgs {
-    /// CA certificate used to sign the RA certificate
-    #[arg(long)]
-    ca_cert: PathBuf,
-
-    /// CA private key used to sign the RA certificate
-    #[arg(long)]
-    ca_key: PathBuf,
-
     /// CA level
     #[arg(long, default_value_t = 1)]
     ca_level: u8,
@@ -334,7 +326,6 @@ fn cmd_gen_app_keys(args: GenAppKeysArgs) -> Result<()> {
     use ra_tls::cert::CertRequest;
     use ra_tls::rcgen::{KeyPair, PKCS_ECDSA_P256_SHA256};
 
-    let ca = CaCert::load(&args.ca_cert, &args.ca_key).context("Failed to read CA certificate")?;
     let key = KeyPair::generate_for(&PKCS_ECDSA_P256_SHA256)?;
     let disk_key = KeyPair::generate_for(&PKCS_ECDSA_P256_SHA256)?;
     let pubkey = key.public_key_der();
@@ -349,12 +340,14 @@ fn cmd_gen_app_keys(args: GenAppKeysArgs) -> Result<()> {
         .key(&key)
         .ca_level(args.ca_level)
         .build();
-    let cert = ca.sign(req).context("Failed to sign certificate")?;
+    let cert = req
+        .self_signed()
+        .context("Failed to self-sign certificate")?;
 
     let app_keys = serde_json::json!({
         "app_key": key.serialize_pem(),
         "disk_crypt_key": sha256(&disk_key.serialize_der()),
-        "certificate_chain": vec![cert.pem(), ca.pem_cert],
+        "certificate_chain": vec![cert.pem()],
     });
     let app_keys = serde_json::to_string(&app_keys).context("Failed to serialize app keys")?;
     fs::write(&args.output, app_keys).context("Failed to write app keys")?;
diff --git a/tdxctl/src/tboot.rs b/tdxctl/src/tboot.rs
index 7724e28..58e88b6 100644
--- a/tdxctl/src/tboot.rs
+++ b/tdxctl/src/tboot.rs
@@ -112,10 +112,6 @@ async fn setup_tproxy_net(args: &TbootArgs, compose: &AppCompose) -> Result<()>
 fn prepare_certs(args: &TbootArgs) -> Result<()> {
     info!("Preparing certs");
     fs::create_dir_all(args.resolve("/etc/tappd"))?;
-    fs::copy(
-        args.resolve("/tapp/certs/ca.cert"),
-        args.resolve("/etc/tappd/ca.cert"),
-    )?;
 
     let appkeys_data = fs::read_to_string(args.resolve("/tapp/appkeys.json"))?;
     let appkeys: AppKeys = serde_json::from_str(&appkeys_data)?;
@@ -125,6 +121,17 @@ fn prepare_certs(args: &TbootArgs) -> Result<()> {
     }
     fs::write(args.resolve("/etc/tappd/app-ca.key"), &appkeys.app_key)?;
 
+    let kms_ca_cert = args.resolve("/tapp/certs/ca.cert");
+    if fs::metadata(&kms_ca_cert).is_ok() {
+        fs::copy(kms_ca_cert, args.resolve("/etc/tappd/ca.cert"))?;
+    } else {
+        // symbolic link the app-ca.cert to ca.cert
+        fs::os::unix::fs::symlink(
+            args.resolve("/etc/tappd/app-ca.cert"),
+            args.resolve("/etc/tappd/ca.cert"),
+        )?;
+    }
+
     let cert_chain_str = appkeys.certificate_chain.join("\n");
     fs::write(args.resolve("/etc/tappd/app-ca.cert"), cert_chain_str)?;