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/*
* Buffered Filter
* (C) 1999-2007 Jack Lloyd
*
* Botan is released under the Simplified BSD License (see license.txt)
*/
#ifndef BOTAN_BUFFERED_FILTER_H_
#define BOTAN_BUFFERED_FILTER_H_
#include <botan/secmem.h>
namespace Botan {
/**
* Filter mixin that breaks input into blocks, useful for
* cipher modes
*/
class BOTAN_PUBLIC_API(2,0) Buffered_Filter
{
public:
/**
* Write bytes into the buffered filter, which will them emit them
* in calls to buffered_block in the subclass
* @param in the input bytes
* @param length of in in bytes
*/
void write(const uint8_t in[], size_t length);
template<typename Alloc>
void write(const std::vector<uint8_t, Alloc>& in, size_t length)
{
write(in.data(), length);
}
/**
* Finish a message, emitting to buffered_block and buffered_final
* Will throw an exception if less than final_minimum bytes were
* written into the filter.
*/
void end_msg();
/**
* Initialize a Buffered_Filter
* @param block_size the function buffered_block will be called
* with inputs which are a multiple of this size
* @param final_minimum the function buffered_final will be called
* with at least this many bytes.
*/
Buffered_Filter(size_t block_size, size_t final_minimum);
virtual ~Buffered_Filter() = default;
protected:
/**
* The block processor, implemented by subclasses
* @param input some input bytes
* @param length the size of input, guaranteed to be a multiple
* of block_size
*/
virtual void buffered_block(const uint8_t input[], size_t length) = 0;
/**
* The final block, implemented by subclasses
* @param input some input bytes
* @param length the size of input, guaranteed to be at least
* final_minimum bytes
*/
virtual void buffered_final(const uint8_t input[], size_t length) = 0;
/**
* @return block size of inputs
*/
size_t buffered_block_size() const { return m_main_block_mod; }
/**
* @return current position in the buffer
*/
size_t current_position() const { return m_buffer_pos; }
/**
* Reset the buffer position
*/
void buffer_reset() { m_buffer_pos = 0; }
private:
size_t m_main_block_mod, m_final_minimum;
secure_vector<uint8_t> m_buffer;
size_t m_buffer_pos;
};
}
#endif
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