crypto,tls: do not ignore BN_get_word error

deps/ncrypto/ncrypto.cc

@@ -408,12 +408,16 @@ bool BignumPointer::setWord(unsigned long w) {  // NOLINT(runtime/int)
   return BN_set_word(bn_.get(), w) == 1;
 }
 
-unsigned long BignumPointer::GetWord(const BIGNUM* bn) {  // NOLINT(runtime/int)
-  return BN_get_word(bn);
+std::optional<unsigned long> BignumPointer::GetWord(  // NOLINT(runtime/int)
+    const BIGNUM* bn) {
+  BN_ULONG ret = BN_get_word(bn);
+  if (ret == static_cast<BN_ULONG>(-1)) return std::nullopt;
+  return ret;
 }
 
-unsigned long BignumPointer::getWord() const {  // NOLINT(runtime/int)
-  if (!bn_) return 0;
+std::optional<unsigned long> BignumPointer::getWord()  // NOLINT(runtime/int)
+    const {
+  if (!bn_) return std::nullopt;
   return GetWord(bn_.get());
 }
 

deps/ncrypto/ncrypto.h

@@ -743,7 +743,7 @@ class BignumPointer final {
   bool isOne() const;
 
   bool setWord(unsigned long w);  // NOLINT(runtime/int)
-  unsigned long getWord() const;  // NOLINT(runtime/int)
+  std::optional<unsigned long> getWord() const;  // NOLINT(runtime/int)
 
   size_t byteLength() const;
 
@@ -782,7 +782,8 @@ class BignumPointer final {
                                  size_t size);
   static int GetBitCount(const BIGNUM* bn);
   static int GetByteCount(const BIGNUM* bn);
-  static unsigned long GetWord(const BIGNUM* bn);  // NOLINT(runtime/int)
+  static std::optional<unsigned long> GetWord(  // NOLINT(runtime/int)
+      const BIGNUM* bn);
   static const BIGNUM* One();
 
   BignumPointer clone();

src/crypto/crypto_aes.cc

@@ -374,7 +374,9 @@ WebCryptoCipherStatus AES_CTR_Cipher(Environment* env,
     return status;
   }
 
-  BN_ULONG input_size_part1 = remaining_until_reset.getWord() * kAesBlockSize;
+  std::optional<BN_ULONG> remaining_blocks = remaining_until_reset.getWord();
+  CHECK(remaining_blocks.has_value());
+  BN_ULONG input_size_part1 = remaining_blocks.value() * kAesBlockSize;
 
   // Encrypt the first part...
   auto status =

src/crypto/crypto_x509.cc

@@ -44,6 +44,7 @@ using v8::Local;
 using v8::LocalVector;
 using v8::MaybeLocal;
 using v8::NewStringType;
+using v8::Null;
 using v8::Object;
 using v8::String;
 using v8::Uint32;
@@ -688,11 +689,12 @@ MaybeLocal<Value> GetModulusString(Environment* env, const BIGNUM* n) {
 }
 
 MaybeLocal<Value> GetExponentString(Environment* env, const BIGNUM* e) {
-  uint64_t exponent_word = static_cast<uint64_t>(BignumPointer::GetWord(e));
+  auto exponent_word = BignumPointer::GetWord(e);
+  if (!exponent_word) return Null(env->isolate());
   auto bio = BIOPointer::NewMem();
   if (!bio) [[unlikely]]
     return {};
-  BIO_printf(bio.get(), "0x%" PRIx64, exponent_word);
+  BIO_printf(bio.get(), "0x%" PRIx64, static_cast<uint64_t>(*exponent_word));
   return ToV8Value(env->context(), bio);
 }