173 lines
4.6 KiB
C++
Executable File
173 lines
4.6 KiB
C++
Executable File
/*
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(**************************************************************************)
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(* *)
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(* Schifra *)
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(* Reed-Solomon Error Correcting Code Library *)
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(* *)
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(* Release Version 0.0.1 *)
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(* http://www.schifra.com *)
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(* Copyright (c) 2000-2020 Arash Partow, All Rights Reserved. *)
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(* *)
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(* The Schifra Reed-Solomon error correcting code library and all its *)
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(* components are supplied under the terms of the General Schifra License *)
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(* agreement. The contents of the Schifra Reed-Solomon error correcting *)
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(* code library and all its components may not be copied or disclosed *)
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(* except in accordance with the terms of that agreement. *)
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(* *)
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(* URL: http://www.schifra.com/license.html *)
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(* *)
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(**************************************************************************)
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*/
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#ifndef INCLUDE_SCHIFRA_CRC_HPP
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#define INCLUDE_SCHIFRA_CRC_HPP
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#include <iostream>
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#include <string>
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namespace schifra
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{
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class crc32
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{
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public:
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typedef std::size_t crc32_t;
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crc32(const crc32_t& _key, const crc32_t& _state = 0x00)
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: key(_key),
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state(_state),
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initial_state(_state)
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{
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initialize_crc32_table();
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}
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void reset()
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{
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state = initial_state;
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}
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void update_1byte(const unsigned char data)
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{
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state = (state >> 8) ^ table[data];
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}
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void update(const unsigned char data[], const std::size_t& count)
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{
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for (std::size_t i = 0; i < count; ++i)
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{
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update_1byte(data[i]);
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}
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}
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void update(char data[], const std::size_t& count)
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{
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for (std::size_t i = 0; i < count; ++i)
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{
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update_1byte(static_cast<unsigned char>(data[i]));
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}
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}
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void update(const std::string& data)
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{
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for (std::size_t i = 0; i < data.size(); ++i)
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{
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update_1byte(static_cast<unsigned char>(data[i]));
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}
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}
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void update(const std::size_t& data)
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{
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update_1byte(static_cast<unsigned char>((data ) & 0xFF));
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update_1byte(static_cast<unsigned char>((data >> 8) & 0xFF));
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update_1byte(static_cast<unsigned char>((data >> 16) & 0xFF));
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update_1byte(static_cast<unsigned char>((data >> 24) & 0xFF));
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}
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crc32_t crc()
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{
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return state;
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}
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private:
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crc32& operator=(const crc32&);
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void initialize_crc32_table()
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{
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for (std::size_t i = 0; i < 0xFF; ++i)
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{
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crc32_t reg = i;
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for (int j = 0; j < 0x08; ++j)
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{
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reg = ((reg & 1) ? (reg >> 1) ^ key : reg >> 1);
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}
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table[i] = reg;
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}
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}
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protected:
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crc32_t key;
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crc32_t state;
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const crc32_t initial_state;
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crc32_t table[256];
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};
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class schifra_crc : public crc32
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{
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public:
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schifra_crc(const crc32_t _key)
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: crc32(_key,0xAAAAAAAA)
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{}
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void update(const unsigned char& data)
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{
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state = ((state >> 8) ^ table[data]) ^ ((state << 8) ^ table[~data]);
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}
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void update(const unsigned char data[], const std::size_t& count)
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{
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for (std::size_t i = 0; i < count; ++i)
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{
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update_1byte(data[i]);
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}
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}
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void update(const char data[], const std::size_t& count)
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{
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for (std::size_t i = 0; i < count; ++i)
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{
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update_1byte(static_cast<unsigned char>(data[i]));
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}
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}
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void update(const std::string& data)
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{
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for (std::size_t i = 0; i < data.size(); ++i)
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{
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update_1byte(static_cast<unsigned char>(data[i]));
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}
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}
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void update(const std::size_t& data)
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{
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update_1byte(static_cast<unsigned char>((data ) & 0xFF));
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update_1byte(static_cast<unsigned char>((data >> 8) & 0xFF));
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update_1byte(static_cast<unsigned char>((data >> 16) & 0xFF));
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update_1byte(static_cast<unsigned char>((data >> 24) & 0xFF));
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}
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};
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} // namespace schifra
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#endif
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