VirgilOperationCipher.h

#ifndef VIRGIL_CRYPTO_VIRGIL_SYMMETRIC_CIPHER_H
#define VIRGIL_CRYPTO_VIRGIL_SYMMETRIC_CIPHER_H

#include <virgil/crypto/VirgilByteArray.h>

#include <memory>

namespace virgil { namespace crypto { inline namespace primitive {

class VirgilOperationCipher {
private:
    template<class Impl>
    struct Model;
public:
    template<class Impl>
    VirgilOperationCipher(Impl impl) : self_(std::make_shared<Model<Impl>>(std::move(impl))) {}

    size_t getKeySize() const {
        return self_->doGetKeySize();
    }

    size_t getNonceSize() const {
        return self_->doGetNonceSize();
    }

    VirgilByteArray encrypt(
            const VirgilByteArray& plainText, const VirgilByteArray& key, const VirgilByteArray& nonce,
            const VirgilByteArray& authData = VirgilByteArray()) const {

        return self_->doEncrypt(plainText, key, nonce, authData);
    }

    VirgilByteArray decrypt(
            const VirgilByteArray& cipherText, const VirgilByteArray& key, const VirgilByteArray& nonce,
            const VirgilByteArray& authData = VirgilByteArray()) const {

        return self_->doDecrypt(cipherText, key, nonce, authData);
    }

    static VirgilOperationCipher getDefault();

private:
    struct Concept {
        virtual size_t doGetKeySize() const = 0;

        virtual size_t doGetNonceSize() const = 0;

        virtual VirgilByteArray doEncrypt(
                const VirgilByteArray& plainText, const VirgilByteArray& key, const VirgilByteArray& nonce,
                const VirgilByteArray& authData) const = 0;

        virtual VirgilByteArray doDecrypt(
                const VirgilByteArray& plainText, const VirgilByteArray& key, const VirgilByteArray& nonce,
                const VirgilByteArray& authData) const = 0;
    };

    template<class Impl>
    struct Model : Concept {

        explicit Model(Impl impl) : impl_(std::move(impl)) {}

        size_t doGetKeySize() const override {
            return impl_.getKeySize();
        }

        size_t doGetNonceSize() const override {
            return impl_.getNonceSize();
        }

        VirgilByteArray doEncrypt(
                const VirgilByteArray& plainText, const VirgilByteArray& key, const VirgilByteArray& nonce,
                const VirgilByteArray& authData) const override {
            return impl_.encrypt(plainText, key, nonce, authData);
        }

        VirgilByteArray doDecrypt(
                const VirgilByteArray& plainText, const VirgilByteArray& key, const VirgilByteArray& nonce,
                const VirgilByteArray& authData) const override {
            return impl_.decrypt(plainText, key, nonce, authData);
        }

    private:
        Impl impl_;
    };

private:
    std::shared_ptr<const Concept> self_;
};

}}}

#endif //VIRGIL_CRYPTO_VIRGIL_SYMMETRIC_CIPHER_H