kdf.hpp

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//---------------------------------------------------------------------------//
// Copyright (c) 2018-2020 Mikhail Komarov <nemo@nil.foundation>
//
// MIT License
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in all
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//
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// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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//---------------------------------------------------------------------------//
 
#ifndef CRYPTO3_ACCUMULATORS_KDF_HPP
#define CRYPTO3_ACCUMULATORS_KDF_HPP
 
#include <boost/container/static_vector.hpp>
 
#include <boost/parameter/value_type.hpp>
 
#include <boost/accumulators/framework/accumulator_base.hpp>
#include <boost/accumulators/framework/extractor.hpp>
#include <boost/accumulators/framework/depends_on.hpp>
#include <boost/accumulators/framework/parameters/sample.hpp>
 
#include <nil/crypto3/block/accumulators/parameters/cipher.hpp>
#include <nil/crypto3/block/accumulators/parameters/bits.hpp>
 
#include <nil/crypto3/detail/make_array.hpp>
#include <nil/crypto3/detail/digest.hpp>
 
#include <nil/crypto3/block/cipher.hpp>
 
namespace nil {
    namespace crypto3 {
        namespace accumulators {
            namespace impl {
                template<typename Mode>
                struct kdf_impl : boost::accumulators::accumulator_base {
                protected:
                    typedef Mode mode_type;
                    typedef typename Mode::cipher_type cipher_type;
                    typedef typename Mode::padding_type padding_type;
 
                    typedef typename mode_type::finalizer_type finalizer_type;
 
                    constexpr static const std::size_t word_bits = mode_type::word_bits;
                    typedef typename mode_type::word_type word_type;
 
                    constexpr static const std::size_t state_bits = mode_type::state_bits;
                    constexpr static const std::size_t state_words = mode_type::state_words;
                    typedef typename mode_type::state_type state_type;
 
                    constexpr static const std::size_t block_bits = mode_type::block_bits;
                    constexpr static const std::size_t block_words = mode_type::block_words;
                    typedef typename mode_type::block_type block_type;
 
                    typedef boost::container::static_vector<word_type, block_words> cache_type;
 
                public:
                    typedef digest<block_bits> result_type;
 
                    template<typename Args>
                    kdf_impl(const Args &args) : cipher(args[accumulators::cipher]), seen(0) {
                    }
 
                    template<typename ArgumentPack>
                    inline void operator()(const ArgumentPack &args) {
                        return process(args[boost::accumulators::sample]);
                    }
 
                    template<typename ArgumentPack>
                    inline result_type result(const ArgumentPack &args) const {
                        result_type res = dgst;
 
                        if (!cache.empty()) {
                            block_type ib = {0};
                            std::move(cache.begin(), cache.end(), ib.begin());
                            block_type ob = cipher.end_message(ib);
                            std::move(ob.begin(), ob.end(), std::inserter(res, res.end()));
                        }
 
                        if (seen % block_bits) {
                            finalizer_type(block_bits - seen % block_bits)(res);
                        } else {
                            finalizer_type(0)(res);
                        }
 
                        return res;
                    }
 
                protected:
                    inline void resolve_type(const word_type &value, std::size_t bits) {
                        if (bits == std::size_t()) {
                            process(value, word_bits);
                        } else {
                            process(value, bits);
                        }
                    }
 
                    inline void resolve_type(const block_type &value, std::size_t bits) {
                        if (bits == std::size_t()) {
                            process(value, block_bits);
                        } else {
                            process(value, bits);
                        }
                    }
 
                    inline void process(const word_type &value, std::size_t bits) {
                        if (cache.size() == cache.max_size()) {
                            block_type ib = {0};
                            std::move(cache.begin(), cache.end(), ib.begin());
                            block_type ob = dgst.empty() ? cipher.begin_message(ib) : cipher.process_block(ib);
                            std::move(ob.begin(), ob.end(), std::inserter(dgst, dgst.end()));
 
                            cache.clear();
                        }
 
                        cache.push_back(value);
                        seen += bits;
                    }
 
                    inline void process(const block_type &block, std::size_t bits) {
                        block_type ob;
                        if (cache.empty()) {
                            ob = dgst.empty() ? cipher.begin_message(block) : cipher.process_block(block);
                        } else {
                            block_type b = make_array<block_words>(cache.begin(), cache.end());
                            typename block_type::const_iterator itr = block.begin() + (cache.max_size() - cache.size());
 
                            std::copy(block.begin(), itr, b.end());
 
                            ob = dgst.empty() ? cipher.begin_message(b) : cipher.process_block(b);
 
                            cache.clear();
                            cache.insert(cache.end(), itr, block.end());
                        }
 
                        std::move(ob.begin(), ob.end(), std::inserter(dgst, dgst.end()));
                        seen += bits;
                    }
 
                    block::cipher<cipher_type, mode_type, padding_type> cipher;
 
                    std::size_t seen;
                    cache_type cache;
                    result_type dgst;
                };
            }    // namespace impl
 
            namespace tag {
                template<typename Mode>
                struct kdf : boost::accumulators::depends_on<> {
                    typedef Mode mode_type;
 
 
                    typedef boost::mpl::always<accumulators::impl::kdf_impl<Mode>> impl;
                };
            }    // namespace tag
 
            namespace extract {
                template<typename Mode, typename AccumulatorSet>
                typename boost::mpl::apply<AccumulatorSet, tag::kdf<Mode>>::type::result_type
                    kdf(const AccumulatorSet &acc) {
                    return boost::accumulators::extract_result<tag::kdf<Mode>>(acc);
                }
            }    // namespace extract
        }        // namespace accumulators
    }            // namespace crypto3
}    // namespace nil
 
#endif    // CRYPTO3_ACCUMULATORS_BLOCK_HPP