/* * Copyright (C) 2011 Sylvain Munaut <tnt@246tNt.com> * * All Rights Reserved * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. */ #pragma once #include <stdint.h> #include <osmocom/core/defs.h> #include <osmocom/core/bits.h> /*! \defgroup a5 GSM A5 ciphering algorithm * @{ * \file a5.h */ /*! Converts a frame number into the 22 bit number used in A5/x * \param[in] fn The true framenumber * \return 22 bit word */ static inline uint32_t osmo_a5_fn_count(uint32_t fn) { int t1 = fn / (26 * 51); int t2 = fn % 26; int t3 = fn % 51; return (t1 << 11) | (t3 << 5) | t2; } /* Notes: * - key must be 8 or 16 (for a5/4) bytes long (or NULL for A5/0) * - the dl and ul pointer must be either NULL or 114 bits long * - fn is the _real_ GSM frame number. * (converted internally to fn_count) */ int osmo_a5(int n, const uint8_t *key, uint32_t fn, ubit_t *dl, ubit_t *ul); void osmo_a5_1(const uint8_t *key, uint32_t fn, ubit_t *dl, ubit_t *ul) OSMO_DEPRECATED("Use generic osmo_a5() instead"); void osmo_a5_2(const uint8_t *key, uint32_t fn, ubit_t *dl, ubit_t *ul) OSMO_DEPRECATED("Use generic osmo_a5() instead"); /*! @} */