src: revert removal of SecureContext `_external` getter

This `_external` getter is essential for some libs to work:
uWebSockets as an example.

PR-URL: https://github.com/nodejs/node/pull/21711
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: James M Snell <jasnell@gmail.com>

2 files changed, 22 insertions, 0 deletions

diff --git a/src/node_crypto.cc b/src/node_crypto.cc
index 9b22edfb96..dd7e0c8468 100644
--- a/src/node_crypto.cc
+++ b/src/node_crypto.cc
@@ -359,6 +359,19 @@ void SecureContext::Initialize(Environment* env, Local<Object> target) {
   t->Set(FIXED_ONE_BYTE_STRING(env->isolate(), "kTicketKeyIVIndex"),
          Integer::NewFromUnsigned(env->isolate(), kTicketKeyIVIndex));
 
+  Local<FunctionTemplate> ctx_getter_templ =
+      FunctionTemplate::New(env->isolate(),
+                            CtxGetter,
+                            env->as_external(),
+                            Signature::New(env->isolate(), t));
+
+
+  t->PrototypeTemplate()->SetAccessorProperty(
+      FIXED_ONE_BYTE_STRING(env->isolate(), "_external"),
+      ctx_getter_templ,
+      Local<FunctionTemplate>(),
+      static_cast<PropertyAttribute>(ReadOnly | DontDelete));
+
   target->Set(secureContextString,
               t->GetFunction(env->context()).ToLocalChecked());
   env->set_secure_context_constructor_template(t);
@@ -1331,6 +1344,14 @@ int SecureContext::TicketCompatibilityCallback(SSL* ssl,
 }
 
 
+void SecureContext::CtxGetter(const FunctionCallbackInfo<Value>& info) {
+  SecureContext* sc;
+  ASSIGN_OR_RETURN_UNWRAP(&sc, info.This());
+  Local<External> ext = External::New(info.GetIsolate(), sc->ctx_.get());
+  info.GetReturnValue().Set(ext);
+}
+
+
 template <bool primary>
 void SecureContext::GetCertificate(const FunctionCallbackInfo<Value>& args) {
   SecureContext* wrap;
diff --git a/src/node_crypto.h b/src/node_crypto.h
index 63d85669fa..2ca333f3c2 100644
--- a/src/node_crypto.h
+++ b/src/node_crypto.h
@@ -165,6 +165,7 @@ class SecureContext : public BaseObject {
       const v8::FunctionCallbackInfo<v8::Value>& args);
   static void EnableTicketKeyCallback(
       const v8::FunctionCallbackInfo<v8::Value>& args);
+  static void CtxGetter(const v8::FunctionCallbackInfo<v8::Value>& info);
 
   template <bool primary>
   static void GetCertificate(const v8::FunctionCallbackInfo<v8::Value>& args);