clarify rustls_client_config_builder_enable_ech arg lifetimes

Author: cpu

src/client.rs

@@ -385,7 +385,9 @@ impl rustls_client_config_builder {
     ///
     /// The provided `ech_config_list_bytes` and `rustls_hpke` must not be NULL or an
     /// error will be returned. The caller maintains ownership of the ECH config list TLS bytes
-    /// and `rustls_hpke` instance.
+    /// and `rustls_hpke` instance. The lifetime of the `ech_config_list_bytes` and `rustls_hpke`
+    /// instance are not tied to the lifetime of the `rustls_client_config_builder` and can be
+    /// freed at any time after this function returns without affecting the builder.
     ///
     /// A `RUSTLS_RESULT_BUILDER_INCOMPATIBLE_TLS_VERSIONS` error is returned if the builder's
     /// TLS versions have been customized via `rustls_client_config_builder_new_custom()`

src/rustls.h

@@ -1768,7 +1768,9 @@ rustls_result rustls_client_config_builder_set_key_log(struct rustls_client_conf
  *
  * The provided `ech_config_list_bytes` and `rustls_hpke` must not be NULL or an
  * error will be returned. The caller maintains ownership of the ECH config list TLS bytes
- * and `rustls_hpke` instance.
+ * and `rustls_hpke` instance. The lifetime of the `ech_config_list_bytes` and `rustls_hpke`
+ * instance are not tied to the lifetime of the `rustls_client_config_builder` and can be
+ * freed at any time after this function returns without affecting the builder.
  *
  * A `RUSTLS_RESULT_BUILDER_INCOMPATIBLE_TLS_VERSIONS` error is returned if the builder's
  * TLS versions have been customized via `rustls_client_config_builder_new_custom()`