botan_block_transform.h

 
#ifndef _security_details_botan_block_transform_h_
#define _security_details_botan_block_transform_h_
 
#include <security/cryptography/i_crypto_transform.h>
#include <system/array.h>
#include <memory>
 
 
namespace System { namespace Security { namespace Cryptography { namespace Details {
 
template<typename botan_type_traits>
class BotanBlockTransform : public ICryptoTransform
{
    typedef typename botan_type_traits::Cipher_Mode     Cipher_Mode;
    typedef typename botan_type_traits::byte            byte;
    template<typename T> using secure_vector = typename botan_type_traits::template secure_vector<T>;
 
public:
    BotanBlockTransform(std::unique_ptr<Cipher_Mode> cipher) : m_cipher(std::move(cipher))
    {}
 
    int TransformBlock(ArrayPtr<uint8_t> inputBuffer, int inputOffset, int inputCount, ArrayPtr<uint8_t> outputBuffer, int outputOffset) override
    {
        secure_vector<byte> buffer(inputCount);
        botan_type_traits::copy_mem(buffer.data(), &inputBuffer->data()[inputOffset], buffer.size());
 
        m_cipher->update(buffer);
 
        botan_type_traits::copy_mem(&outputBuffer->data()[outputOffset], buffer.data(), buffer.size());
 
        return ASPOSECPP_CHECKED_CAST(int, buffer.size());
    }
 
    ArrayPtr<uint8_t> TransformFinalBlock(ArrayPtr<uint8_t> inputBuffer, int inputOffset, int inputCount) override
    {
        secure_vector<byte> buffer(inputCount);
        botan_type_traits::copy_mem(buffer.data(), &inputBuffer->data()[inputOffset], buffer.size());
                
        m_cipher->finish(buffer);
 
        ArrayPtr<uint8_t> result = MakeObject<Array<uint8_t>>(ASPOSECPP_CHECKED_CAST(int, buffer.size()));
        botan_type_traits::copy_mem(&result->data()[0], buffer.data(), buffer.size());
        return result;
    }
 
    int get_InputBlockSize() override
    {
        int size = ASPOSECPP_CHECKED_CAST(int, m_cipher->minimum_final_size());
        return size ? size : 16;
    }
    int get_OutputBlockSize() override
    {
        return ASPOSECPP_CHECKED_CAST(int, m_cipher->output_length(get_InputBlockSize()));
    }
 
private:
    std::unique_ptr<Cipher_Mode> m_cipher;
};
 
}}}}
 
#endif