Method VerifySignature

cpp/src/parquet/metadata.cc:807–839

  }

  bool VerifySignature(const void* signature) {
    // verify decryption properties are set
    if (file_decryptor_ == nullptr) {
      throw ParquetException("Decryption not set properly. cannot verify signature");
    }
    // serialize the footer
    uint8_t* serialized_data;
    uint32_t serialized_len = metadata_len_;
    ThriftSerializer serializer;
    serializer.SerializeToBuffer(metadata_.get(), &serialized_len, &serialized_data);
    std::span<const uint8_t> serialized_data_span(serialized_data, serialized_len);

    // encrypt with nonce
    std::span<const uint8_t> nonce(reinterpret_cast<const uint8_t*>(signature),
                                   encryption::kNonceLength);
    auto tag = reinterpret_cast<const uint8_t*>(signature) + encryption::kNonceLength;

    const SecureString& key = file_decryptor_->GetFooterKey();
    const std::string& aad = encryption::CreateFooterAad(file_decryptor_->file_aad());

    auto aes_encryptor = encryption::AesEncryptor::Make(file_decryptor_->algorithm(),
                                                        static_cast<int>(key.size()),
                                                        true, false /*write_length*/);

    std::shared_ptr<Buffer> encrypted_buffer = AllocateBuffer(
        file_decryptor_->pool(), aes_encryptor->CiphertextLength(serialized_len));
    int32_t encrypted_len = aes_encryptor->SignedFooterEncrypt(
        serialized_data_span, key.as_span(), str2span(aad), nonce,
        encrypted_buffer->mutable_span_as<uint8_t>());
    return 0 ==
           memcmp(encrypted_buffer->data() + encrypted_len - encryption::kGcmTagLength,
                  tag, encryption::kGcmTagLength);
  }

  inline uint32_t size() const { return metadata_len_; }
  inline int num_columns() const { return schema_.num_columns(); }