crypto.hpp

#include <steamclient/utilities/err.h>
 
#include <cstdint>
#include <steamclient/crypto/helpers.hpp>
#include <steamclient/types/clientmsg.hpp>
#include <steamclient/types/generated/SteamLanguageInternal.hpp>
#include <steamclient/types/packetbase.hpp>
#include <vector>
 
namespace Steam::Crypto {
constexpr uint8_t STEAM_PUBLIC_KEY_DER[] = {
    0x30, 0x81, 0x9D, 0x30, 0x0D, 0x06, 0x09, 0x2A, 0x86, 0x48, 0x86, 0xF7,
    0x0D, 0x01, 0x01, 0x01, 0x05, 0x00, 0x03, 0x81, 0x8B, 0x00, 0x30, 0x81,
    0x87, 0x02, 0x81, 0x81, 0x00, 0xDF, 0xEC, 0x1A, 0xD6, 0x2C, 0x10, 0x66,
    0x2C, 0x17, 0x35, 0x3A, 0x14, 0xB0, 0x7C, 0x59, 0x11, 0x7F, 0x9D, 0xD3,
    0xD8, 0x2B, 0x7A, 0xE3, 0xE0, 0x15, 0xCD, 0x19, 0x1E, 0x46, 0xE8, 0x7B,
    0x87, 0x74, 0xA2, 0x18, 0x46, 0x31, 0xA9, 0x03, 0x14, 0x79, 0x82, 0x8E,
    0xE9, 0x45, 0xA2, 0x49, 0x12, 0xA9, 0x23, 0x68, 0x73, 0x89, 0xCF, 0x69,
    0xA1, 0xB1, 0x61, 0x46, 0xBD, 0xC1, 0xBE, 0xBF, 0xD6, 0x01, 0x1B, 0xD8,
    0x81, 0xD4, 0xDC, 0x90, 0xFB, 0xFE, 0x4F, 0x52, 0x73, 0x66, 0xCB, 0x95,
    0x70, 0xD7, 0xC5, 0x8E, 0xBA, 0x1C, 0x7A, 0x33, 0x75, 0xA1, 0x62, 0x34,
    0x46, 0xBB, 0x60, 0xB7, 0x80, 0x68, 0xFA, 0x13, 0xA7, 0x7A, 0x8A, 0x37,
    0x4B, 0x9E, 0xC6, 0xF4, 0x5D, 0x5F, 0x3A, 0x99, 0xF9, 0x9E, 0xC4, 0x3A,
    0xE9, 0x63, 0xA2, 0xBB, 0x88, 0x19, 0x28, 0xE0, 0xE7, 0x14, 0xC0, 0x42,
    0x89, 0x02, 0x01, 0x11};
 
class EncryptionManager {
 public:
  EncryptionManager()
      : session_key_(Steam::Crypto::Helpers::generate_random_bytes(32, rng_)),
        hmac_secret_(session_key_.begin(), session_key_.begin() + 16) {}
 
  const inline CryptoPP::AutoSeededRandomPool& get_rng() const { return rng_; };
  const inline std::vector<uint8_t>& get_session_key() const {
    return session_key_;
  };
  const inline std::vector<uint8_t>& get_hmac_secret() const {
    return hmac_secret_;
  };
 
  inline static std::vector<uint8_t> getSteamPublicKey() {
    return std::vector<uint8_t>(
        STEAM_PUBLIC_KEY_DER,
        STEAM_PUBLIC_KEY_DER + sizeof(STEAM_PUBLIC_KEY_DER));
  }
 
  Steam::Messaging::ClientMessages::Msg<
      Steam::Internal::MsgChannelEncryptResponse>
  generate_encryption_response(
      const Steam::Messaging::Packets::PacketMsg& packet);
 
  std::vector<uint8_t> process_incoming_encrypted_message(
      const std::vector<uint8_t>& frame);
 
  std::vector<uint8_t> process_outgoing_encrypted_message(
      const std::vector<uint8_t>& frame);
 
 private:
  CryptoPP::AutoSeededRandomPool rng_;  // persistent encryption RNG
  std::vector<uint8_t> session_key_;    // 32 byte session key
  std::vector<uint8_t>
      hmac_secret_;  // hmac secret (first 16 bytes of the session_key_)
};
}  // namespace Steam::Crypto