open5gs/src/mme/mme-kdf.c

70 lines
1.7 KiB
C

/*
* Copyright (C) 2019 by Sukchan Lee <acetcom@gmail.com>
*
* This file is part of Open5GS.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero 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, see <https://www.gnu.org/licenses/>.
*/
#include "ogs-crypt.h"
void mme_kdf_nas(uint8_t algorithm_type_distinguishers,
uint8_t algorithm_identity, const uint8_t *kasme, uint8_t *knas)
{
uint8_t s[7];
uint8_t out[32];
s[0] = 0x15; /* FC Value */
s[1] = algorithm_type_distinguishers;
s[2] = 0x00;
s[3] = 0x01;
s[4] = algorithm_identity;
s[5] = 0x00;
s[6] = 0x01;
ogs_hmac_sha256(kasme, 32, s, 7, out, 32);
memcpy(knas, out+16, 16);
}
void mme_kdf_enb(const uint8_t *kasme, uint32_t ul_count, uint8_t *kenb)
{
uint8_t s[7];
s[0] = 0x11; /* FC Value */
ul_count = htonl(ul_count);
memcpy(s+1, &ul_count, 4);
s[5] = 0x00;
s[6] = 0x04;
ogs_hmac_sha256(kasme, 32, s, 7, kenb, 32);
}
void mme_kdf_nh(const uint8_t *kasme, const uint8_t *sync_input, uint8_t *kenb)
{
uint8_t s[35];
s[0] = 0x12; /* FC Value */
memcpy(s+1, sync_input, 32);
s[33] = 0x00;
s[34] = 0x20;
ogs_hmac_sha256(kasme, 32, s, 35, kenb, 32);
}