68 lines
2.5 KiB
C++
68 lines
2.5 KiB
C++
/***************************************************************************
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* Copyright (C) 2021 - 2023 by Federico Amedeo Izzo IU2NUO, *
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* Niccolò Izzo IU2KIN *
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* Frederik Saraci IU2NRO *
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* Silvano Seva IU2KWO *
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* *
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* Adapted from original code written by Rob Riggs, Mobilinkd LLC *
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* *
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* This program is free software; you can redistribute it and/or modify *
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* it under the terms of the GNU General Public License as published by *
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* the Free Software Foundation; either version 3 of the License, or *
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* (at your option) any later version. *
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* *
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* This program is distributed in the hope that it will be useful, *
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* but WITHOUT ANY WARRANTY; without even the implied warranty of *
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
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* GNU General Public License for more details. *
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* *
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* You should have received a copy of the GNU General Public License *
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* along with this program; if not, see <http://www.gnu.org/licenses/> *
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***************************************************************************/
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#ifndef M17_DECORRELATOR_H
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#define M17_DECORRELATOR_H
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#ifndef __cplusplus
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#error This header is C++ only!
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#endif
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#include <experimental/array>
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#include <string>
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#include <array>
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namespace M17
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{
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/**
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* Decorrelator sequence for data randomisation.
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*/
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static constexpr std::array< uint8_t, 46 > sequence =
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{
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0xd6, 0xb5, 0xe2, 0x30, 0x82, 0xFF, 0x84, 0x62,
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0xba, 0x4e, 0x96, 0x90, 0xd8, 0x98, 0xdd, 0x5d,
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0x0c, 0xc8, 0x52, 0x43, 0x91, 0x1d, 0xf8, 0x6e,
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0x68, 0x2F, 0x35, 0xda, 0x14, 0xea, 0xcd, 0x76,
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0x19, 0x8d, 0xd5, 0x80, 0xd1, 0x33, 0x87, 0x13,
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0x57, 0x18, 0x2d, 0x29, 0x78, 0xc3
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};
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/**
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* Apply M17 decorrelation scheme to a byte array.
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*
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* \param data: byte array to be decorrelated..
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*/
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template <size_t N >
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inline void decorrelate(std::array< uint8_t, N >& data)
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{
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for (size_t i = 0; i < N; i++)
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{
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data[i] ^= sequence[i];
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}
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}
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} // namespace M17
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#endif // M17_DECORRELATOR_H
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