message: Add a check if ciphertext is too short.
diff: @@ -175,6 +175,9 @@ util::Status AesGcmHkdfStreamSegmentDecrypter::DecryptSegment(
  if (ciphertext.size() > get_ciphertext_segment_size()) {
  return util::Status(util::error::INVALID_ARGUMENT, "ciphertext too long");
  }
  + if (ciphertext.size() < AesGcmHkdfStreamSegmentEncrypter::kTagSizeInBytes) {
  + return util::Status(util::error::INVALID_ARGUMENT, "ciphertext too short");
  + }
  if (plaintext_buffer == nullptr) {
  return util::Status(util::error::INVALID_ARGUMENT,
  "plaintext_buffer must be non-null");
  