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Diffstat (limited to 'src/gsm/gea.c')
-rw-r--r-- | src/gsm/gea.c | 60 |
1 files changed, 60 insertions, 0 deletions
diff --git a/src/gsm/gea.c b/src/gsm/gea.c new file mode 100644 index 00000000..b8f6768a --- /dev/null +++ b/src/gsm/gea.c @@ -0,0 +1,60 @@ +/* + * gea.c + * + * Implementation of GEA3 and GEA4 + * + * Copyright (C) 2016 by Sysmocom s.f.m.c. GmbH + * + * 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 3 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. + */ + +#include <osmocom/core/bits.h> +#include <osmocom/crypt/gprs_cipher.h> +#include <osmocom/crypt/auth.h> +#include <osmocom/gsm/kasumi.h> + +#include <stdint.h> +#include <string.h> + +/*! \brief Performs the GEA4 algorithm as in 3GPP TS 55.226 V9.0.0 + * \param[in,out] out Buffer for gamma for encrypted/decrypted + * \param[in] len Length of out, in bytes + * \param[in] kc Buffer with the ciphering key + * \param[in] iv Init vector + * \param[in] direct Direction: 0 (MS -> SGSN) or 1 (SGSN -> MS) + */ +int gea4(uint8_t *out, uint16_t len, uint8_t *kc, uint32_t iv, + enum gprs_cipher_direction direction) +{ + _kasumi_kgcore(0xFF, 0, iv, direction, kc, out, len * 8); + return 0; +} + +/*! \brief Performs the GEA3 algorithm as in 3GPP TS 55.216 V6.2.0 + * \param[in,out] out Buffer for gamma for encrypted/decrypted + * \param[in] len Length of out, in bytes + * \param[in] kc Buffer with the ciphering key + * \param[in] iv Init vector + * \param[in] direct Direction: 0 (MS -> SGSN) or 1 (SGSN -> MS) + */ +int gea3(uint8_t *out, uint16_t len, uint8_t *kc, uint32_t iv, + enum gprs_cipher_direction direction) +{ + uint8_t ck[gprs_cipher_key_length(GPRS_ALGO_GEA4)]; + osmo_c4(ck, kc); + return gea4(out, len, ck, iv, direction); +} |