tls: avoid taking ownership of OpenSSL objects

It is often unnecessary to obtain (shared) ownership of OpenSSL objects
in this code, and it generally is more costly to do so as opposed to
just obtaining a pointer to the respective OpenSSL object. Therefore,
this patch replaces various OpenSSL function calls that take ownership
with ones that do not.

src/crypto/crypto_common.cc

@@ -425,20 +425,15 @@ MaybeLocal<Value> GetCurveName(Environment* env, const int nid) {
       MaybeLocal<Value>(Undefined(env->isolate()));
 }
 
-MaybeLocal<Value> GetECPubKey(
-    Environment* env,
-    const EC_GROUP* group,
-    const ECPointer& ec) {
-  const EC_POINT* pubkey = EC_KEY_get0_public_key(ec.get());
+MaybeLocal<Value> GetECPubKey(Environment* env,
+                              const EC_GROUP* group,
+                              const EC_KEY* ec) {
+  const EC_POINT* pubkey = EC_KEY_get0_public_key(ec);
   if (pubkey == nullptr)
     return Undefined(env->isolate());
 
-  return ECPointToBuffer(
-      env,
-      group,
-      pubkey,
-      EC_KEY_get_conv_form(ec.get()),
-      nullptr).FromMaybe(Local<Object>());
+  return ECPointToBuffer(env, group, pubkey, EC_KEY_get_conv_form(ec), nullptr)
+      .FromMaybe(Local<Object>());
 }
 
 MaybeLocal<Value> GetECGroupBits(Environment* env, const EC_GROUP* group) {
@@ -452,8 +447,8 @@ MaybeLocal<Value> GetECGroupBits(Environment* env, const EC_GROUP* group) {
   return Integer::New(env->isolate(), bits);
 }
 
-MaybeLocal<Object> GetPubKey(Environment* env, const RSAPointer& rsa) {
-  int size = i2d_RSA_PUBKEY(rsa.get(), nullptr);
+MaybeLocal<Object> GetPubKey(Environment* env, const RSA* rsa) {
+  int size = i2d_RSA_PUBKEY(rsa, nullptr);
   CHECK_GE(size, 0);
 
   std::unique_ptr<BackingStore> bs;
@@ -463,7 +458,7 @@ MaybeLocal<Object> GetPubKey(Environment* env, const RSAPointer& rsa) {
   }
 
   unsigned char* serialized = reinterpret_cast<unsigned char*>(bs->Data());
-  CHECK_GE(i2d_RSA_PUBKEY(rsa.get(), &serialized), 0);
+  CHECK_GE(i2d_RSA_PUBKEY(rsa, &serialized), 0);
 
   Local<ArrayBuffer> ab = ArrayBuffer::New(env->isolate(), std::move(bs));
   return Buffer::New(env, ab, 0, ab->ByteLength()).FromMaybe(Local<Object>());
@@ -1125,8 +1120,8 @@ MaybeLocal<Object> GetEphemeralKey(Environment* env, const SSLPointer& ssl) {
       {
         const char* curve_name;
         if (kid == EVP_PKEY_EC) {
-          ECKeyPointer ec(EVP_PKEY_get1_EC_KEY(key.get()));
-          int nid = EC_GROUP_get_curve_name(EC_KEY_get0_group(ec.get()));
+          const EC_KEY* ec = EVP_PKEY_get0_EC_KEY(key.get());
+          int nid = EC_GROUP_get_curve_name(EC_KEY_get0_group(ec));
           curve_name = OBJ_nid2sn(nid);
         } else {
           curve_name = OBJ_nid2sn(kid);
@@ -1285,24 +1280,24 @@ MaybeLocal<Object> X509ToObject(
     return MaybeLocal<Object>();
   }
 
-  EVPKeyPointer pkey(X509_get_pubkey(cert));
-  RSAPointer rsa;
-  ECPointer ec;
-  if (pkey) {
-    switch (EVP_PKEY_id(pkey.get())) {
+  const EVP_PKEY* pkey = X509_get0_pubkey(cert);
+  const RSA* rsa = nullptr;
+  const EC_KEY* ec = nullptr;
+  if (pkey != nullptr) {
+    switch (EVP_PKEY_id(pkey)) {
       case EVP_PKEY_RSA:
-        rsa.reset(EVP_PKEY_get1_RSA(pkey.get()));
+        rsa = EVP_PKEY_get0_RSA(pkey);
         break;
       case EVP_PKEY_EC:
-        ec.reset(EVP_PKEY_get1_EC_KEY(pkey.get()));
+        ec = EVP_PKEY_get0_EC_KEY(pkey);
         break;
     }
   }
 
   if (rsa) {
     const BIGNUM* n;
     const BIGNUM* e;
-    RSA_get0_key(rsa.get(), &n, &e, nullptr);
+    RSA_get0_key(rsa, &n, &e, nullptr);
     if (!Set<Value>(context,
                     info,
                     env->modulus_string(),
@@ -1319,7 +1314,7 @@ MaybeLocal<Object> X509ToObject(
       return MaybeLocal<Object>();
     }
   } else if (ec) {
-    const EC_GROUP* group = EC_KEY_get0_group(ec.get());
+    const EC_GROUP* group = EC_KEY_get0_group(ec);
 
     if (!Set<Value>(
             context, info, env->bits_string(), GetECGroupBits(env, group)) ||
@@ -1348,11 +1343,6 @@ MaybeLocal<Object> X509ToObject(
     }
   }
 
-  // pkey, rsa, and ec pointers are no longer needed.
-  pkey.reset();
-  rsa.reset();
-  ec.reset();
-
   if (!Set<Value>(context,
                   info,
                   env->valid_from_string(),