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include/utils/encryption.hpp

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+/*
+  Copyright <2018-2022> <scott.e.graves@protonmail.com>
+
+  Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
+  associated documentation files (the "Software"), to deal in the Software without restriction,
+  including without limitation the rights to use, copy, modify, merge, publish, distribute,
+  sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
+  furnished to do so, subject to the following conditions:
+
+  The above copyright notice and this permission notice shall be included in all copies or
+  substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT
+  NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+  DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT
+  OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+*/
+#ifndef INCLUDE_UTILS_ENCRYPTION_HPP_
+#define INCLUDE_UTILS_ENCRYPTION_HPP_
+
+#include "common.hpp"
+#include "types/repertory.hpp"
+#include "utils/encrypting_reader.hpp"
+
+namespace repertory::utils::encryption {
+// Prototypes
+api_error decrypt_file_name(const std::string &encryption_token, std::string &file_name);
+
+CryptoPP::SecByteBlock generate_key(const std::string &encryption_token);
+
+api_error read_encrypted_range(
+    const http_range &range, const CryptoPP::SecByteBlock &key,
+    const std::function<api_error(std::vector<char> &ct, const std::uint64_t &start_offset,
+                                  const std::uint64_t &end_offset)> &reader,
+    const std::uint64_t &total_size, std::vector<char> &data);
+
+// Implementations
+template <typename result>
+static bool decrypt_data(const CryptoPP::SecByteBlock &key, const char *buffer,
+                         const std::size_t &buffer_size, result &res) {
+  const auto header_size =
+      static_cast<std::uint32_t>(encrypting_reader::get_header_size());
+  if (buffer_size > header_size) {
+    CryptoPP::XChaCha20Poly1305::Decryption decryption;
+    CryptoPP::SecByteBlock iv(decryption.IVSize());
+    std::memcpy(&iv[0u], &buffer[0u], iv.size());
+
+    CryptoPP::SecByteBlock mac(decryption.DigestSize());
+    std::memcpy(&mac[0u], &buffer[iv.size()], mac.size());
+    decryption.SetKeyWithIV(key, key.size(), iv, iv.size());
+
+    const std::uint32_t size =
+        boost::endian::native_to_big(static_cast<std::uint32_t>(buffer_size));
+    res.resize(buffer_size - header_size);
+    return decryption.DecryptAndVerify(
+        reinterpret_cast<CryptoPP::byte *>(&res[0u]), &mac[0u], mac.size(), &iv[0u],
+        static_cast<int>(iv.size()), reinterpret_cast<const CryptoPP::byte *>(&size), sizeof(size),
+        reinterpret_cast<const CryptoPP::byte *>(&buffer[header_size]), res.size());
+  }
+
+  return false;
+}
+
+template <typename buffer, typename result>
+static bool decrypt_data(const CryptoPP::SecByteBlock &key, const buffer &buf, result &res) {
+  return decrypt_data<result>(key, &buf[0u], buf.size(), res);
+}
+
+template <typename buffer, typename result>
+static bool decrypt_data(const std::string &encryption_token, const buffer &buf, result &res) {
+  return decrypt_data<buffer, result>(generate_key(encryption_token), buf, res);
+}
+
+template <typename result>
+static bool decrypt_data(const std::string &encryption_token, const char *buffer,
+                         const std::size_t &buffer_size, result &res) {
+  return decrypt_data<result>(generate_key(encryption_token), buffer, buffer_size, res);
+}
+
+template <typename result>
+static void encrypt_data(const CryptoPP::SecByteBlock &key, const char *buffer,
+                         const std::size_t &buffer_size, result &res) {
+  CryptoPP::XChaCha20Poly1305::Encryption encryption;
+
+  CryptoPP::SecByteBlock iv(encryption.IVSize());
+  CryptoPP::OS_GenerateRandomBlock(false, iv, iv.size());
+
+  CryptoPP::SecByteBlock mac(encryption.DigestSize());
+  const std::uint32_t header_size =
+      static_cast<std::uint32_t>(encrypting_reader::get_header_size());
+  const std::uint32_t size =
+      boost::endian::native_to_big(static_cast<std::uint32_t>(buffer_size + header_size));
+
+  encryption.SetKeyWithIV(key, key.size(), iv, iv.size());
+
+  res.resize(buffer_size + header_size);
+  encryption.EncryptAndAuthenticate(reinterpret_cast<CryptoPP::byte *>(&res[header_size]), &mac[0u],
+                                    mac.size(), &iv[0u], static_cast<int>(iv.size()),
+                                    reinterpret_cast<const CryptoPP::byte *>(&size), sizeof(size),
+                                    reinterpret_cast<const CryptoPP::byte *>(buffer), buffer_size);
+  std::memcpy(&res[0u], &iv[0u], iv.size());
+  std::memcpy(&res[iv.size()], &mac[0u], mac.size());
+}
+
+template <typename result>
+static void encrypt_data(const std::string &encryption_token, const char *buffer,
+                         const std::size_t &buffer_size, result &res) {
+  return encrypt_data<result>(generate_key(encryption_token), buffer, buffer_size, res);
+}
+
+template <typename buffer, typename result>
+static void encrypt_data(const std::string &encryption_token, const buffer &buf, result &res) {
+  return encrypt_data<result>(generate_key(encryption_token), &buf[0u], buf.size(), res);
+}
+
+template <typename buffer, typename result>
+static void encrypt_data(const CryptoPP::SecByteBlock &key, const buffer &buf, result &res) {
+  return encrypt_data<result>(key, &buf[0u], buf.size(), res);
+}
+} // namespace repertory::utils::encryption
+
+#endif // INCLUDE_UTILS_ENCRYPTION_HPP_