src: refactor crypto code with RAII cleanup

use more idiomatic expressions with RAII primitives,
instead of old style goto

PR-URL: #23014

Reviewed-By: Daniel Bevenius <[email protected]>
Reviewed-By: James M Snell <[email protected]>
Reviewed-By: Sakthipriyan Vairamani <[email protected]>
Reviewed-By: Anna Henningsen <[email protected]>
Reviewed-By: Colin Ihrig <[email protected]>
Reviewed-By: Tobias Nießen <[email protected]>
Reviewed-By: Joyee Cheung <[email protected]>
Reviewed-By: Ruben Bridgewater <[email protected]>

src/node_crypto_clienthello.cc

@@ -74,6 +74,12 @@ bool ClientHelloParser::ParseRecordHeader(const uint8_t* data, size_t avail) {
 
 void ClientHelloParser::ParseHeader(const uint8_t* data, size_t avail) {
   ClientHello hello;
+  bool failed = true;
+
+  OnScopeLeave cleanup([&]() {
+    if (failed)
+      End();
+  });
 
   // >= 5 + frame size bytes for frame parsing
   if (body_offset_ + frame_len_ > avail)
@@ -88,23 +94,23 @@ void ClientHelloParser::ParseHeader(const uint8_t* data, size_t avail) {
   if (data[body_offset_ + 4] != 0x03 ||
       data[body_offset_ + 5] < 0x01 ||
       data[body_offset_ + 5] > 0x03) {
-    goto fail;
+    return;
   }
 
   if (data[body_offset_] == kClientHello) {
     if (state_ == kTLSHeader) {
       if (!ParseTLSClientHello(data, avail))
-        goto fail;
+        return;
     } else {
       // We couldn't get here, but whatever
-      goto fail;
+      return;
     }
 
     // Check if we overflowed (do not reply with any private data)
     if (session_id_ == nullptr ||
         session_size_ > 32 ||
         session_id_ + session_size_ > data + avail) {
-      goto fail;
+      return;
     }
   }
 
@@ -116,10 +122,8 @@ void ClientHelloParser::ParseHeader(const uint8_t* data, size_t avail) {
   hello.servername_ = servername_;
   hello.servername_size_ = static_cast<uint8_t>(servername_size_);
   onhello_cb_(cb_arg_, hello);
+  failed = false;
   return;
-
- fail:
-  End();
 }