cbc.hpp

Go to the documentation of this file.

//---------------------------------------------------------------------------//
 
// Copyright (c) 2019-2020 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
// copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.
//---------------------------------------------------------------------------//
 
#ifndef CRYPTO3_BLOCK_MODE_CIPHER_BLOCK_CHAINING_HPP
#define CRYPTO3_BLOCK_MODE_CIPHER_BLOCK_CHAINING_HPP
 
#include <boost/integer.hpp>
 
#include <nil/crypto3/modes/mode.hpp>
#include <nil/crypto3/modes/cts.hpp>
#include <nil/crypto3/modes/padding.hpp>
 
#include <nil/crypto3/codec/algorithm/encode.hpp>
 
//#include <nil/crypto3/codec/logic.hpp>
 
namespace nil {
    namespace crypto3 {
        namespace block {
            namespace modes {
                namespace detail {
                    template<typename Cipher, typename Padding, template<typename> class Allocator = std::allocator>
                    struct cbc_policy {
                        typedef std::size_t size_type;
 
                        typedef Cipher cipher_type;
                        typedef Padding padding_type;
 
                        constexpr static const size_type block_bits = cipher_type::block_bits;
                        constexpr static const size_type block_words = cipher_type::block_words;
                        typedef typename cipher_type::block_type block_type;
 
                        typedef std::vector<boost::uint_t<CHAR_BIT>, Allocator<boost::uint_t<CHAR_BIT>>> iv_type;
                    };
 
                    template<typename Cipher, typename Padding, typename CiphertextStealingMode>
                    struct cbc_encryption_policy : public cbc_policy<Cipher, Padding> {};
 
                    template<typename Cipher, typename Padding>
                    struct cbc_encryption_policy<Cipher, Padding, cts<0, Cipher, Padding>>
                        : public cbc_policy<Cipher, Padding> {
                        typedef typename cbc_policy<Cipher, Padding>::size_type size_type;
 
                        typedef typename cbc_policy<Cipher, Padding>::cipher_type cipher_type;
                        typedef typename cbc_policy<Cipher, Padding>::padding_type padding_type;
 
                        constexpr static const size_type block_bits = cbc_policy<Cipher, Padding>::block_bits;
                        constexpr static const size_type block_words = cbc_policy<Cipher, Padding>::block_words;
                        typedef typename cbc_policy<Cipher, Padding>::block_type block_type;
 
                        typedef typename cbc_policy<Cipher, Padding>::iv_type iv_type;
 
                        inline static block_type begin_message(const cipher_type &cipher, const block_type &plaintext,
                                                               const iv_type &iv = iv_type()) {
                            block_type block = {0};
 
                            //                        codec::encode<codec::encoder::logic_xor>(plaintext, iv,
                            //                        block.begin());
 
                            return cipher.encrypt(block);
                        }
 
                        inline static block_type process_block(const cipher_type &cipher, const block_type &plaintext,
                                                               const block_type &previous = block_type()) {
                            block_type block = {0};
 
                            //                        codec::encode<codec::encoder::logic_xor>(plaintext, previous,
                            //                        block.begin());
 
                            return cipher.encrypt(block);
                        }
 
                        inline static block_type end_message(const cipher_type &cipher, const block_type &plaintext,
                                                             const block_type &previous = block_type(),
                                                             const iv_type &iv = iv_type()) {
                            block_type result = {0};
                            std::array<uint8_t, block_bits / CHAR_BIT> byte_array = {0};
 
                            pack(plaintext, byte_array);
 
                            size_type rem = std::count(byte_array.begin(), byte_array.end(), block_type::value_type()) %
                                            (block_bits / CHAR_BIT);
                            if (rem || padding_type::always_pad) {
                                block_type padbuffer = padding_type::pad(plaintext, rem), block;
                                //                            codec::encode<codec::encoder::logic_xor>(!iv.empty() ? iv
                                //                            : previous, padbuffer, block .begin());
                                result = cipher.encrypt(block);
                            }
 
                            return result;
                        }
                    };
 
                    template<typename Cipher, typename Padding>
                    struct cbc_encryption_policy<Cipher, Padding, cts<1, Cipher, Padding>>
                        : public cbc_policy<Cipher, Padding> {
                        typedef typename cbc_policy<Cipher, Padding>::size_type size_type;
 
                        typedef typename cbc_policy<Cipher, Padding>::cipher_type cipher_type;
                        typedef typename cbc_policy<Cipher, Padding>::padding_type padding_type;
 
                        constexpr static const size_type block_bits = cbc_policy<Cipher, Padding>::block_bits;
                        constexpr static const size_type block_words = cbc_policy<Cipher, Padding>::block_words;
                        typedef typename cbc_policy<Cipher, Padding>::block_type block_type;
 
                        typedef typename cbc_policy<Cipher, Padding>::iv_type iv_type;
 
                        inline static block_type begin_message(const cipher_type &cipher, const block_type &plaintext,
                                                               const iv_type &iv = iv_type()) {
                            block_type block = {0};
 
                            //                        codec::encode<codec::encoder::logic_xor>(plaintext, iv,
                            //                        block.begin());
 
                            return cipher.encrypt(block);
                        }
 
                        inline static block_type process_block(const cipher_type &cipher, const block_type &plaintext,
                                                               const block_type &previous = block_type()) {
                            block_type block = {0};
 
                            //                        codec::encode<codec::encoder::logic_xor>(plaintext, previous,
                            //                        block.begin());
 
                            return cipher.encrypt(block);
                        }
 
                        inline static block_type end_message(const cipher_type &cipher, const block_type &plaintext,
                                                             const block_type &previous = block_type(),
                                                             const iv_type &iv = iv_type()) {
                            block_type result = {0};
                            std::array<uint8_t, block_bits / CHAR_BIT> byte_array = {0};
 
                            pack(plaintext, byte_array);
 
                            size_type rem = std::count(byte_array.begin(), byte_array.end(), block_type::value_type()) %
                                            (block_bits / CHAR_BIT);
                            if (rem || padding_type::always_pad) {
                                block_type padbuffer = padding_type::pad(plaintext, rem), block;
                                //                            codec::encode<codec::encoder::logic_xor>(!iv.empty() ? iv
                                //                            : previous, padbuffer, block .begin());
                                result = cipher.encrypt(block);
                            }
 
                            return result;
                        }
                    };
 
                    template<typename Cipher, typename Padding>
                    struct cbc_encryption_policy<Cipher, Padding, cts<2, Cipher, Padding>>
                        : public cbc_policy<Cipher, Padding> {
                        typedef typename cbc_policy<Cipher, Padding>::size_type size_type;
 
                        typedef typename cbc_policy<Cipher, Padding>::cipher_type cipher_type;
                        typedef typename cbc_policy<Cipher, Padding>::padding_type padding_type;
 
                        constexpr static const size_type block_bits = cbc_policy<Cipher, Padding>::block_bits;
                        constexpr static const size_type block_words = cbc_policy<Cipher, Padding>::block_words;
                        typedef typename cbc_policy<Cipher, Padding>::block_type block_type;
 
                        typedef typename cbc_policy<Cipher, Padding>::iv_type iv_type;
 
                        inline static block_type begin_message(const cipher_type &cipher, const block_type &plaintext,
                                                               const iv_type &iv = iv_type()) {
                            block_type block = {0};
 
                            //                        codec::encode<codec::encoder::logic_xor>(plaintext, iv,
                            //                        block.begin());
 
                            return cipher.encrypt(block);
                        }
 
                        inline static block_type process_block(const cipher_type &cipher, const block_type &plaintext,
                                                               const block_type &previous = block_type()) {
                            block_type block = {0};
 
                            //                        codec::encode<codec::encoder::logic_xor>(plaintext, previous,
                            //                        block.begin());
 
                            return cipher.encrypt(block);
                        }
 
                        inline static block_type end_message(const cipher_type &cipher, const block_type &plaintext,
                                                             const block_type &previous = block_type(),
                                                             const iv_type &iv = iv_type()) {
                            block_type result = {0};
                            std::array<uint8_t, block_bits / CHAR_BIT> byte_array = {0};
 
                            pack(plaintext, byte_array);
 
                            size_type rem = std::count(byte_array.begin(), byte_array.end(), block_type::value_type()) %
                                            (block_bits / CHAR_BIT);
                            if (rem || padding_type::always_pad) {
                                block_type padbuffer = padding_type::pad(plaintext, rem), block;
                                //                            codec::encode<codec::encoder::logic_xor>(!iv.empty() ? iv
                                //                            : previous, padbuffer, block .begin());
                                result = cipher.encrypt(block);
                            }
 
                            return result;
                        }
                    };
 
                    template<typename Cipher, typename Padding>
                    struct cbc_encryption_policy<Cipher, Padding, cts<3, Cipher, Padding>>
                        : public cbc_policy<Cipher, Padding> {
                        typedef typename cbc_policy<Cipher, Padding>::size_type size_type;
 
                        typedef typename cbc_policy<Cipher, Padding>::cipher_type cipher_type;
                        typedef typename cbc_policy<Cipher, Padding>::padding_type padding_type;
 
                        constexpr static const size_type block_bits = cbc_policy<Cipher, Padding>::block_bits;
                        constexpr static const size_type block_words = cbc_policy<Cipher, Padding>::block_words;
                        typedef typename cbc_policy<Cipher, Padding>::block_type block_type;
 
                        typedef typename cbc_policy<Cipher, Padding>::iv_type iv_type;
 
                        inline static block_type begin_message(const cipher_type &cipher, const block_type &plaintext,
                                                               const iv_type &iv = iv_type()) {
                            block_type block = {0};
 
                            //                        codec::encode<codec::encoder::logic_xor>(plaintext, iv,
                            //                        block.begin());
 
                            return cipher.encrypt(block);
                        }
 
                        inline static block_type process_block(const cipher_type &cipher, const block_type &plaintext,
                                                               const block_type &previous = block_type()) {
                            block_type block = {0};
 
                            //                        codec::encode<codec::encoder::logic_xor>(plaintext, previous,
                            //                        block.begin());
 
                            return cipher.encrypt(block);
                        }
 
                        inline static block_type end_message(const cipher_type &cipher, const block_type &plaintext,
                                                             const block_type &previous = block_type(),
                                                             const iv_type &iv = iv_type()) {
                            BOOST_ASSERT_MSG(buffer.size() >= offset, "Offset is sane");
                            uint8_t *buf = buffer.data() + offset;
                            const size_t sz = buffer.size() - offset;
 
                            const size_t BS = block_size();
 
                            if (sz < BS + 1) {
                                throw encoding_error(name() + ": insufficient data to encipher");
                            }
 
                            if (sz % BS == 0) {
                                update(buffer, offset);
 
                                // swap last two blocks
                                for (size_t i = 0; i != BS; ++i) {
                                    std::swap(buffer[buffer.size() - BS + i], buffer[buffer.size() - 2 * BS + i]);
                                }
                            } else {
                                const size_t full_blocks = ((sz / BS) - 1) * BS;
                                const size_t final_bytes = sz - full_blocks;
                                BOOST_ASSERT_MSG(final_bytes > BS && final_bytes < 2 * BS,
                                                 "Left over size in expected range");
 
                                secure_vector<uint8_t> last(buf + full_blocks, buf + full_blocks + final_bytes);
                                buffer.resize(full_blocks + offset);
                                update(buffer, offset);
 
                                xor_buf(last.data(), state_ptr(), BS);
                                cipher().encrypt(last.data());
 
                                for (size_t i = 0; i != final_bytes - BS; ++i) {
                                    last[i] ^= last[i + BS];
                                    last[i + BS] ^= last[i];
                                }
 
                                cipher().encrypt(last.data());
 
                                buffer += last;
                            }
                        }
                    };
 
                    template<typename Cipher, typename Padding, typename CiphertextStealingMode>
                    struct cbc_decryption_policy : public cbc_policy<Cipher, Padding> {};
 
                    template<typename Cipher, typename Padding>
                    struct cbc_decryption_policy<Cipher, Padding, cts<0, Cipher, Padding>>
                        : public cbc_policy<Cipher, Padding> {
                        typedef typename cbc_policy<Cipher, Padding>::size_type size_type;
 
                        typedef typename cbc_policy<Cipher, Padding>::cipher_type cipher_type;
                        typedef typename cbc_policy<Cipher, Padding>::padding_type padding_type;
 
                        constexpr static const std::size_t block_bits = cbc_policy<Cipher, Padding>::block_bits;
                        constexpr static const std::size_t block_words = cbc_policy<Cipher, Padding>::block_words;
                        typedef typename cbc_policy<Cipher, Padding>::block_type block_type;
 
                        typedef typename cbc_policy<Cipher, Padding>::iv_type iv_type;
 
                        inline static block_type begin_message(const cipher_type &cipher, const block_type &plaintext,
                                                               const iv_type &iv = iv_type()) {
                            block_type block = cipher.decrypt(plaintext);
 
                            //                        codec::encode<codec::encoder::logic_xor>(block, iv);
 
                            return block;
                        }
 
                        inline static block_type process_block(const cipher_type &cipher, const block_type &plaintext,
                                                               const block_type &previous = block_type()) {
                            const size_t BS = block_size();
 
                            BOOST_ASSERT_MSG(sz % BS == 0, "Input is full blocks");
                            size_t blocks = sz / BS;
 
                            while (blocks) {
                                const size_t to_proc = std::min(BS * blocks, m_tempbuf.size());
 
                                cipher().decrypt_n(buf, m_tempbuf.data(), to_proc / BS);
 
                                xor_buf(m_tempbuf.data(), state_ptr(), BS);
                                xor_buf(&m_tempbuf[BS], buf, to_proc - BS);
                                copy_mem(state_ptr(), buf + (to_proc - BS), BS);
 
                                copy_mem(buf, m_tempbuf.data(), to_proc);
 
                                buf += to_proc;
                                blocks -= to_proc / BS;
                            }
 
                            return sz;
                        }
 
                        inline static block_type end_message(const cipher_type &cipher, const block_type &plaintext,
                                                             const iv_type &iv = iv_type()) {
                            BOOST_ASSERT_MSG(buffer.size() >= offset, "Offset is sane");
                            const size_t sz = buffer.size() - offset;
 
                            const size_t BS = block_size();
 
                            if (sz == 0 || sz % BS) {
                                throw decoding_error(name() + ": Ciphertext not a multiple of block size");
                            }
 
                            update(buffer, offset);
 
                            const size_t pad_bytes = BS - padding().unpad(&buffer[buffer.size() - BS], BS);
                            buffer.resize(buffer.size() - pad_bytes); // remove padding
                            if (pad_bytes == 0 && padding().name() != "NoPadding") {
                                throw decoding_error(name());
                            }
                        }
                    };
 
                    template<typename Cipher, typename Padding>
                    struct cbc_decryption_policy<Cipher, Padding, cts<1, Cipher, Padding>>
                        : public cbc_policy<Cipher, Padding> {
                        typedef typename cbc_policy<Cipher, Padding>::size_type size_type;
 
                        typedef typename cbc_policy<Cipher, Padding>::cipher_type cipher_type;
                        typedef typename cbc_policy<Cipher, Padding>::padding_type padding_type;
 
                        constexpr static const std::size_t block_bits = cbc_policy<Cipher, Padding>::block_bits;
                        constexpr static const std::size_t block_words = cbc_policy<Cipher, Padding>::block_words;
                        typedef typename cbc_policy<Cipher, Padding>::block_type block_type;
 
                        typedef typename cbc_policy<Cipher, Padding>::iv_type iv_type;
 
                        inline static block_type begin_message(const cipher_type &cipher, const block_type &plaintext,
                                                               const iv_type &iv = iv_type()) {
                            block_type block = cipher.decrypt(plaintext);
 
                            //                        codec::encode<codec::encoder::logic_xor>(block, iv);
 
                            return block;
                        }
 
                        inline static block_type process_block(const cipher_type &cipher, const block_type &plaintext,
                                                               const block_type &previous = block_type()) {
                            block_type result = cipher.decrypt(plaintext);
 
                            //                        codec::encode<codec::encoder::logic_xor>(result, previous);
 
                            return result;
                        }
 
                        inline static block_type end_message(const cipher_type &cipher, const block_type &plaintext,
                                                             const iv_type &iv = iv_type()) {
                            block_type result = cipher.decrypt(plaintext);
 
                            //                        codec::encode<codec::encoder::logic_xor>(result, iv);
 
                            return result;
                        }
                    };
 
                    template<typename Cipher, typename Padding>
                    struct cbc_decryption_policy<Cipher, Padding, cts<2, Cipher, Padding>>
                        : public cbc_policy<Cipher, Padding> {
                        typedef typename cbc_policy<Cipher, Padding>::size_type size_type;
 
                        typedef typename cbc_policy<Cipher, Padding>::cipher_type cipher_type;
                        typedef typename cbc_policy<Cipher, Padding>::padding_type padding_type;
 
                        constexpr static const std::size_t block_bits = cbc_policy<Cipher, Padding>::block_bits;
                        constexpr static const std::size_t block_words = cbc_policy<Cipher, Padding>::block_words;
                        typedef typename cbc_policy<Cipher, Padding>::block_type block_type;
 
                        typedef typename cbc_policy<Cipher, Padding>::iv_type iv_type;
 
                        inline static block_type begin_message(const cipher_type &cipher, const block_type &plaintext,
                                                               const iv_type &iv = iv_type()) {
                            block_type block = cipher.decrypt(plaintext);
 
                            //                        codec::encode<codec::encoder::logic_xor>(block, iv);
 
                            return block;
                        }
 
                        inline static block_type process_block(const cipher_type &cipher, const block_type &plaintext,
                                                               const block_type &previous = block_type()) {
                            block_type result = cipher.decrypt(plaintext);
 
                            //                        codec::encode<codec::encoder::logic_xor>(result, previous);
 
                            return result;
                        }
 
                        inline static block_type end_message(const cipher_type &cipher, const block_type &plaintext,
                                                             const iv_type &iv = iv_type()) {
                            block_type result = cipher.decrypt(plaintext);
 
                            //                        codec::encode<codec::encoder::logic_xor>(result, iv);
 
                            return result;
                        }
                    };
 
                    template<typename Cipher, typename Padding>
                    struct cbc_decryption_policy<Cipher, Padding, cts<3, Cipher, Padding>>
                        : public cbc_policy<Cipher, Padding> {
                        typedef typename cbc_policy<Cipher, Padding>::size_type size_type;
 
                        typedef typename cbc_policy<Cipher, Padding>::cipher_type cipher_type;
                        typedef typename cbc_policy<Cipher, Padding>::padding_type padding_type;
 
                        constexpr static const std::size_t block_bits = cbc_policy<Cipher, Padding>::block_bits;
                        constexpr static const std::size_t block_words = cbc_policy<Cipher, Padding>::block_words;
                        typedef typename cbc_policy<Cipher, Padding>::block_type block_type;
 
                        typedef typename cbc_policy<Cipher, Padding>::iv_type iv_type;
 
                        inline static block_type begin_message(const cipher_type &cipher, const block_type &plaintext,
                                                               const iv_type &iv = iv_type()) {
                            block_type block = cipher.decrypt(plaintext);
 
                            //                        codec::encode<codec::encoder::logic_xor>(block, iv);
 
                            return block;
                        }
 
                        inline static block_type process_block(const cipher_type &cipher, const block_type &plaintext,
                                                               const block_type &previous = block_type()) {
                            block_type result = cipher.decrypt(plaintext);
 
                            //                        codec::encode<codec::encoder::logic_xor>(result, previous);
 
                            return result;
                        }
 
                        inline static block_type end_message(const cipher_type &cipher, const block_type &plaintext,
                                                             const iv_type &iv = iv_type()) {
                            BOOST_ASSERT_MSG(buffer.size() >= offset, "Offset is sane");
                            const size_t sz = buffer.size() - offset;
                            uint8_t *buf = buffer.data() + offset;
 
                            const size_t BS = block_size();
 
                            if (sz < BS + 1) {
                                throw encoding_error(name() + ": insufficient data to isomorphic_decryption_mode");
                            }
 
                            if (sz % BS == 0) {
                                // swap last two blocks
 
                                for (size_t i = 0; i != BS; ++i) {
                                    std::swap(buffer[buffer.size() - BS + i], buffer[buffer.size() - 2 * BS + i]);
                                }
 
                                update(buffer, offset);
                            } else {
                                const size_t full_blocks = ((sz / BS) - 1) * BS;
                                const size_t final_bytes = sz - full_blocks;
                                BOOST_ASSERT_MSG(final_bytes > BS && final_bytes < 2 * BS, "Left over size in expected range");
 
                                secure_vector<uint8_t> last(buf + full_blocks, buf + full_blocks + final_bytes);
                                buffer.resize(full_blocks + offset);
                                update(buffer, offset);
 
                                cipher().decrypt(last.data());
 
                                xor_buf(last.data(), &last[BS], final_bytes - BS);
 
                                for (size_t i = 0; i != final_bytes - BS; ++i) {
                                    std::swap(last[i], last[i + BS]);
                                }
 
                                cipher().decrypt(last.data());
                                xor_buf(last.data(), state_ptr(), BS);
 
                                buffer += last;
                            }
                        }
                    };
 
                    template<typename Policy>
                    class cipher_block_chaining {
                        typedef Policy policy_type;
 
                    public:
                        typedef typename policy_type::cipher_type cipher_type;
                        typedef typename policy_type::padding_type padding_type;
 
                        typedef typename policy_type::size_type size_type;
 
                        typedef typename cipher_type::key_type key_type;
                        typedef typename policy_type::iv_type iv_type;
 
                        constexpr static const size_type block_bits = policy_type::block_bits;
                        constexpr static const size_type block_words = policy_type::block_words;
                        typedef typename cipher_type::block_type block_type;
 
                        cipher_block_chaining(const cipher_type &cipher) : cipher(cipher) {
                        }
 
                        block_type begin_message(const block_type &plaintext, const iv_type &iv = iv_type()) {
                            previous = policy_type::begin_message(cipher, plaintext, iv);
                            return previous;
                        }
 
                        block_type process_block(const block_type &plaintext) {
                            previous = policy_type::process_block(cipher, plaintext, previous);
                            return previous;
                        }
 
                        block_type end_message(const block_type &plaintext, const iv_type &iv = iv_type()) {
                            return policy_type::end_message(cipher, plaintext, iv);
                        }
 
                        inline static size_type required_output_size(size_type inputlen) {
                            return padding_type::required_output_size(inputlen);
                        }
 
                    protected:
                        block_type previous;
                        cipher_type cipher;
                    };
                }    // namespace detail
 
                template<typename Cipher, template<typename> class Padding,
                         template<typename, template<typename> class> class CiphertextStealingMode = cts0>
                struct cipher_block_chaining {
                    typedef Cipher cipher_type;
                    typedef Padding<Cipher> padding_type;
                    typedef CiphertextStealingMode<Cipher, Padding> ciphertext_stealing_type;
 
                    typedef detail::cbc_encryption_policy<cipher_type, padding_type, ciphertext_stealing_type>
                        encryption_policy;
                    typedef detail::cbc_decryption_policy<cipher_type, padding_type, ciphertext_stealing_type>
                        decryption_policy;
 
                    template<template<typename, typename> class Policy>
                    struct bind {
                        typedef detail::cipher_block_chaining<Policy<cipher_type, padding_type>> type;
                    };
                };
 
                template<typename Cipher, template<typename> class Padding,
                         template<typename, template<typename> class> class CiphertextStealingMode>
                using cbc = cipher_block_chaining<Cipher, Padding, CiphertextStealingMode>;
            }    // namespace modes
        }        // namespace block
    }    // namespace crypto3
}    // namespace nil
 
#endif