fix(tls): throw meaningful error when hostname is invalid (#10387)

`InvalidDNSNameError` is thrown when a string is not a valid hostname,
e.g. it contains invalid characters, or starts with a numeric digit. It
does not involve a (failed) DNS lookup.

1 files changed, 11 insertions, 10 deletions

diff --git a/runtime/ops/tls.rs b/runtime/ops/tls.rs
index 10293cf92..0dbf35cc4 100644
--- a/runtime/ops/tls.rs
+++ b/runtime/ops/tls.rs
@@ -13,6 +13,7 @@ use deno_core::error::bad_resource;
 use deno_core::error::bad_resource_id;
 use deno_core::error::custom_error;
 use deno_core::error::generic_error;
+use deno_core::error::invalid_hostname;
 use deno_core::error::AnyError;
 use deno_core::AsyncRefCell;
 use deno_core::CancelHandle;
@@ -139,8 +140,8 @@ async fn op_start_tls(
   }
 
   let tls_connector = TlsConnector::from(Arc::new(config));
-  let dnsname = DNSNameRef::try_from_ascii_str(&domain)
-    .map_err(|_| generic_error("Invalid DNS lookup"))?;
+  let dnsname = DNSNameRef::try_from_ascii_str(domain)
+    .map_err(|_| invalid_hostname(domain))?;
   let tls_stream = tls_connector.connect(dnsname, tcp_stream).await?;
 
   let rid = {
@@ -169,20 +170,22 @@ async fn op_connect_tls(
 ) -> Result<OpConn, AnyError> {
   assert_eq!(args.transport, "tcp");
 
+  let mut domain = args.hostname.as_str();
+  if domain.is_empty() {
+    domain = "localhost";
+  }
   {
     let mut s = state.borrow_mut();
     let permissions = s.borrow_mut::<Permissions>();
-    permissions.net.check(&(&args.hostname, Some(args.port)))?;
+    permissions.net.check(&(domain, Some(args.port)))?;
     if let Some(path) = &args.cert_file {
       permissions.read.check(Path::new(&path))?;
     }
   }
-  let mut domain = args.hostname.as_str();
-  if domain.is_empty() {
-    domain = "localhost";
-  }
 
-  let addr = resolve_addr(&args.hostname, args.port)
+  let dnsname = DNSNameRef::try_from_ascii_str(domain)
+    .map_err(|_| invalid_hostname(domain))?;
+  let addr = resolve_addr(domain, args.port)
     .await?
     .next()
     .ok_or_else(|| generic_error("No resolved address found"))?;
@@ -200,8 +203,6 @@ async fn op_connect_tls(
     config.root_store.add_pem_file(reader).unwrap();
   }
   let tls_connector = TlsConnector::from(Arc::new(config));
-  let dnsname = DNSNameRef::try_from_ascii_str(&domain)
-    .map_err(|_| generic_error("Invalid DNS lookup"))?;
   let tls_stream = tls_connector.connect(dnsname, tcp_stream).await?;
   let rid = {
     let mut state_ = state.borrow_mut();