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-rw-r--r--src/shared/libosmocore/src/gsm/a5.c367
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diff --git a/src/shared/libosmocore/src/gsm/a5.c b/src/shared/libosmocore/src/gsm/a5.c
deleted file mode 100644
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--- a/src/shared/libosmocore/src/gsm/a5.c
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@@ -1,367 +0,0 @@
-/*
- * a5.c
- *
- * Full reimplementation of A5/1,2 (split and threadsafe)
- *
- * The logic behind the algorithm is taken from "A pedagogical implementation
- * of the GSM A5/1 and A5/2 "voice privacy" encryption algorithms." by
- * Marc Briceno, Ian Goldberg, and David Wagner.
- *
- * 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.
- *
- * You should have received a copy of the GNU General Public License along
- * with this program; if not, write to the Free Software Foundation, Inc.,
- * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
- */
-
-/*! \addtogroup a5
- * @{
- */
-
-/*! \file gsm/a5.c
- * \brief Osmocom GSM A5 ciphering algorithm implementation
- */
-
-#include <string.h>
-
-#include <osmocom/gsm/a5.h>
-
-/*! \brief Main method to generate a A5/x cipher stream
- * \param[in] n Which A5/x method to use
- * \param[in] key 8 byte array for the key (as received from the SIM)
- * \param[in] fn Frame number
- * \param[out] dl Pointer to array of ubits to return Downlink cipher stream
- * \param[out] ul Pointer to array of ubits to return Uplink cipher stream
- *
- * Currently A5/[0-2] are supported.
- * Either (or both) of dl/ul can be NULL if not needed.
- */
-void
-osmo_a5(int n, const uint8_t *key, uint32_t fn, ubit_t *dl, ubit_t *ul)
-{
- switch (n)
- {
- case 0:
- if (dl)
- memset(dl, 0x00, 114);
- if (ul)
- memset(ul, 0x00, 114);
- break;
-
- case 1:
- osmo_a5_1(key, fn, dl, ul);
- break;
-
- case 2:
- osmo_a5_2(key, fn, dl, ul);
- break;
-
- default:
- /* a5/[3..7] not supported here/yet */
- break;
- }
-}
-
-
-/* ------------------------------------------------------------------------ */
-/* A5/1&2 common stuff */
-/* ------------------------------------------------------------------------ */
-
-#define A5_R1_LEN 19
-#define A5_R2_LEN 22
-#define A5_R3_LEN 23
-#define A5_R4_LEN 17 /* A5/2 only */
-
-#define A5_R1_MASK ((1<<A5_R1_LEN)-1)
-#define A5_R2_MASK ((1<<A5_R2_LEN)-1)
-#define A5_R3_MASK ((1<<A5_R3_LEN)-1)
-#define A5_R4_MASK ((1<<A5_R4_LEN)-1)
-
-#define A5_R1_TAPS 0x072000 /* x^19 + x^18 + x^17 + x^14 + 1 */
-#define A5_R2_TAPS 0x300000 /* x^22 + x^21 + 1 */
-#define A5_R3_TAPS 0x700080 /* x^23 + x^22 + x^21 + x^8 + 1 */
-#define A5_R4_TAPS 0x010800 /* x^17 + x^12 + 1 */
-
-/*! \brief Computes parity of a 32-bit word
- * \param[in] x 32 bit word
- * \return Parity bit (xor of all bits) as 0 or 1
- */
-static inline uint32_t
-_a5_12_parity(uint32_t x)
-{
- x ^= x >> 16;
- x ^= x >> 8;
- x ^= x >> 4;
- x &= 0xf;
- return (0x6996 >> x) & 1;
-}
-
-/*! \brief Compute majority bit from 3 taps
- * \param[in] v1 LFSR state ANDed with tap-bit
- * \param[in] v2 LFSR state ANDed with tap-bit
- * \param[in] v3 LFSR state ANDed with tap-bit
- * \return The majority bit (0 or 1)
- */
-static inline uint32_t
-_a5_12_majority(uint32_t v1, uint32_t v2, uint32_t v3)
-{
- return (!!v1 + !!v2 + !!v3) >= 2;
-}
-
-/*! \brief Compute the next LFSR state
- * \param[in] r Current state
- * \param[in] mask LFSR mask
- * \param[in] taps LFSR taps
- * \return Next state
- */
-static inline uint32_t
-_a5_12_clock(uint32_t r, uint32_t mask, uint32_t taps)
-{
- return ((r << 1) & mask) | _a5_12_parity(r & taps);
-}
-
-
-/* ------------------------------------------------------------------------ */
-/* A5/1 */
-/* ------------------------------------------------------------------------ */
-
-#define A51_R1_CLKBIT 0x000100
-#define A51_R2_CLKBIT 0x000400
-#define A51_R3_CLKBIT 0x000400
-
-/*! \brief GSM A5/1 Clocking function
- * \param[in] r Register state
- * \param[in] force Non-zero value disable conditional clocking
- */
-static inline void
-_a5_1_clock(uint32_t r[], int force)
-{
- int cb[3], maj;
-
- cb[0] = !!(r[0] & A51_R1_CLKBIT);
- cb[1] = !!(r[1] & A51_R2_CLKBIT);
- cb[2] = !!(r[2] & A51_R3_CLKBIT);
-
- maj = _a5_12_majority(cb[0], cb[1], cb[2]);
-
- if (force || (maj == cb[0]))
- r[0] = _a5_12_clock(r[0], A5_R1_MASK, A5_R1_TAPS);
-
- if (force || (maj == cb[1]))
- r[1] = _a5_12_clock(r[1], A5_R2_MASK, A5_R2_TAPS);
-
- if (force || (maj == cb[2]))
- r[2] = _a5_12_clock(r[2], A5_R3_MASK, A5_R3_TAPS);
-}
-
-/*! \brief GSM A5/1 Output function
- * \param[in] r Register state
- * \return The A5/1 output function bit
- */
-static inline uint8_t
-_a5_1_get_output(uint32_t r[])
-{
- return (r[0] >> (A5_R1_LEN-1)) ^
- (r[1] >> (A5_R2_LEN-1)) ^
- (r[2] >> (A5_R3_LEN-1));
-}
-
-/*! \brief Generate a GSM A5/1 cipher stream
- * \param[in] key 8 byte array for the key (as received from the SIM)
- * \param[in] fn Frame number
- * \param[out] dl Pointer to array of ubits to return Downlink cipher stream
- * \param[out] ul Pointer to array of ubits to return Uplink cipher stream
- *
- * Either (or both) of dl/ul can be NULL if not needed.
- */
-void
-osmo_a5_1(const uint8_t *key, uint32_t fn, ubit_t *dl, ubit_t *ul)
-{
- uint32_t r[3] = {0, 0, 0};
- uint32_t fn_count;
- uint32_t b;
- int i;
-
- /* Key load */
- for (i=0; i<64; i++)
- {
- b = ( key[7 - (i>>3)] >> (i&7) ) & 1;
-
- _a5_1_clock(r, 1);
-
- r[0] ^= b;
- r[1] ^= b;
- r[2] ^= b;
- }
-
- /* Frame count load */
- fn_count = osmo_a5_fn_count(fn);
-
- for (i=0; i<22; i++)
- {
- b = (fn_count >> i) & 1;
-
- _a5_1_clock(r, 1);
-
- r[0] ^= b;
- r[1] ^= b;
- r[2] ^= b;
- }
-
- /* Mix */
- for (i=0; i<100; i++)
- {
- _a5_1_clock(r, 0);
- }
-
- /* Output */
- for (i=0; i<114; i++) {
- _a5_1_clock(r, 0);
- if (dl)
- dl[i] = _a5_1_get_output(r);
- }
-
- for (i=0; i<114; i++) {
- _a5_1_clock(r, 0);
- if (ul)
- ul[i] = _a5_1_get_output(r);
- }
-}
-
-
-/* ------------------------------------------------------------------------ */
-/* A5/2 */
-/* ------------------------------------------------------------------------ */
-
-#define A52_R4_CLKBIT0 0x000400
-#define A52_R4_CLKBIT1 0x000008
-#define A52_R4_CLKBIT2 0x000080
-
-/*! \brief GSM A5/2 Clocking function
- * \param[in] r Register state
- * \param[in] force Non-zero value disable conditional clocking
- */
-static inline void
-_a5_2_clock(uint32_t r[], int force)
-{
- int cb[3], maj;
-
- cb[0] = !!(r[3] & A52_R4_CLKBIT0);
- cb[1] = !!(r[3] & A52_R4_CLKBIT1);
- cb[2] = !!(r[3] & A52_R4_CLKBIT2);
-
- maj = (cb[0] + cb[1] + cb[2]) >= 2;
-
- if (force || (maj == cb[0]))
- r[0] = _a5_12_clock(r[0], A5_R1_MASK, A5_R1_TAPS);
-
- if (force || (maj == cb[1]))
- r[1] = _a5_12_clock(r[1], A5_R2_MASK, A5_R2_TAPS);
-
- if (force || (maj == cb[2]))
- r[2] = _a5_12_clock(r[2], A5_R3_MASK, A5_R3_TAPS);
-
- r[3] = _a5_12_clock(r[3], A5_R4_MASK, A5_R4_TAPS);
-}
-
-/*! \brief GSM A5/2 Output function
- * \param[in] r Register state
- * \return The A5/2 output function bit
- */
-static inline uint8_t
-_a5_2_get_output(uint32_t r[])
-{
- uint8_t b;
-
- b = (r[0] >> (A5_R1_LEN-1)) ^
- (r[1] >> (A5_R2_LEN-1)) ^
- (r[2] >> (A5_R3_LEN-1)) ^
- _a5_12_majority( r[0] & 0x08000, ~r[0] & 0x04000, r[0] & 0x1000) ^
- _a5_12_majority(~r[1] & 0x10000, r[1] & 0x02000, r[1] & 0x0200) ^
- _a5_12_majority( r[2] & 0x40000, r[2] & 0x10000, ~r[2] & 0x2000);
-
- return b;
-}
-
-/*! \brief Generate a GSM A5/1 cipher stream
- * \param[in] key 8 byte array for the key (as received from the SIM)
- * \param[in] fn Frame number
- * \param[out] dl Pointer to array of ubits to return Downlink cipher stream
- * \param[out] ul Pointer to array of ubits to return Uplink cipher stream
- *
- * Either (or both) of dl/ul can be NULL if not needed.
- */
-void
-osmo_a5_2(const uint8_t *key, uint32_t fn, ubit_t *dl, ubit_t *ul)
-{
- uint32_t r[4] = {0, 0, 0, 0};
- uint32_t fn_count;
- uint32_t b;
- int i;
-
- /* Key load */
- for (i=0; i<64; i++)
- {
- b = ( key[7 - (i>>3)] >> (i&7) ) & 1;
-
- _a5_2_clock(r, 1);
-
- r[0] ^= b;
- r[1] ^= b;
- r[2] ^= b;
- r[3] ^= b;
- }
-
- /* Frame count load */
- fn_count = osmo_a5_fn_count(fn);
-
- for (i=0; i<22; i++)
- {
- b = (fn_count >> i) & 1;
-
- _a5_2_clock(r, 1);
-
- r[0] ^= b;
- r[1] ^= b;
- r[2] ^= b;
- r[3] ^= b;
- }
-
- r[0] |= 1 << 15;
- r[1] |= 1 << 16;
- r[2] |= 1 << 18;
- r[3] |= 1 << 10;
-
- /* Mix */
- for (i=0; i<99; i++)
- {
- _a5_2_clock(r, 0);
- }
-
- /* Output */
- for (i=0; i<114; i++) {
- _a5_2_clock(r, 0);
- if (dl)
- dl[i] = _a5_2_get_output(r);
- }
-
- for (i=0; i<114; i++) {
- _a5_2_clock(r, 0);
- if (ul)
- ul[i] = _a5_2_get_output(r);
- }
-}
-
-/*! @} */
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