Class AESCipherTCP

payload.cpp:781–833

    "0123456789+/";
    
class AESCipherTCP {
private:
    std::vector<uint8_t> key;
    AES_ctx ctx;

    std::vector<uint8_t> pad(const std::vector<uint8_t>& data) {
        size_t pad_len = 16 - (data.size() % 16);
        std::vector<uint8_t> padded = data;
        padded.insert(padded.end(), pad_len, static_cast<uint8_t>(pad_len));
        return padded;
    }

    std::vector<uint8_t> unpad(const std::vector<uint8_t>& data) {
        if (data.empty()) return data;
        uint8_t pad_len = data.back();
        if (pad_len > 16 || pad_len == 0) return data;
        return std::vector<uint8_t>(data.begin(), data.end() - pad_len);
    }

public:
    AESCipherTCP(const std::string& key_str) {
        key = std::vector<uint8_t>(key_str.begin(), key_str.end());
        if (key.size() != 16 && key.size() != 24 && key.size() != 32) {
            throw std::runtime_error("Key must be 16, 24, or 32 bytes long");
        }
        AES_init_ctx(&ctx, key.data());
    }

    std::vector<uint8_t> encrypt(const std::string& raw) {
        std::vector<uint8_t> data(raw.begin(), raw.end());
        data = pad(data);
        std::vector<uint8_t> iv(16);
        for (size_t i = 0; i < 16; ++i) iv[i] = rand() % 256;
        std::vector<uint8_t> result = iv;
        AES_ctx ctx_copy = ctx;
        AES_ctx_set_iv(&ctx_copy, iv.data());
        AES_CBC_encrypt_buffer(&ctx_copy, data.data(), data.size());
        result.insert(result.end(), data.begin(), data.end());
        return result;
    }

    std::string decrypt(const std::vector<uint8_t>& enc) {
        if (enc.size() < 16) throw std::runtime_error("Invalid encrypted data");
        std::vector<uint8_t> iv(enc.begin(), enc.begin() + 16);
        std::vector<uint8_t> data(enc.begin() + 16, enc.end());
        if (data.size() % 16 != 0) throw std::runtime_error("Invalid data length");
        AES_ctx ctx_copy = ctx;
        AES_ctx_set_iv(&ctx_copy, iv.data());
        AES_CBC_decrypt_buffer(&ctx_copy, data.data(), data.size());
        data = unpad(data);
        return std::string(data.begin(), data.end());
    }
};

void send_data(SOCKET sock, const std::vector<uint8_t>& data) {
    uint32_t length = static_cast<uint32_t>(data.size());