xbot/ref.hpp

#pragma once

#include <openssl/evp.h>
#include <openssl/x509.h>

#include <memory>

template <typename> struct RefTraits {};

template <> struct RefTraits<EVP_PKEY> {
    static constexpr void (*Free)(EVP_PKEY*) = EVP_PKEY_free;
    static constexpr int (*UpRef)(EVP_PKEY*) = EVP_PKEY_up_ref;
};

template <> struct RefTraits<X509> {
    static constexpr void (*Free)(X509*) = X509_free;
    static constexpr int (*UpRef)(X509*) = X509_up_ref;
};

template <> struct RefTraits<EVP_PKEY_CTX> {
    static constexpr void (*Free)(EVP_PKEY_CTX*) = EVP_PKEY_CTX_free;
};

template <typename T>
struct FnDeleter {
    auto operator()(T *ptr) const -> void { RefTraits<T>::Free(ptr); }
};

template <typename T>
struct Ref : std::unique_ptr<T, FnDeleter<T>> {
    using std::unique_ptr<T, FnDeleter<T>>::unique_ptr;
    Ref(const Ref &ref) {
        *this = ref;
    }
    Ref &operator=(const Ref &ref) {
        RefTraits<T>::UpRef(ref.get());
        this->reset(ref.get());
        return *this;
    }
};

using EVP_PKEY_CTX_Ref = Ref<EVP_PKEY_CTX>;
using X509_Ref = Ref<X509>;
using EVP_PKEY_Ref = Ref<EVP_PKEY>;