Files
openairinterface5g/openair-cn/SECU/key_nas_encryption.c
T

49 lines
1.2 KiB
C

#include <string.h>
#include "secu_defs.h"
/*!
* Derive the kNASenc from kasme and perform truncate on the generated key to
* reduce his size to 128 bits. Definition of the derivation function can
* be found in 3GPP TS.33401 #A.7
* @param[in] nas_alg_type NAS algorithm distinguisher
* @param[in] nas_enc_alg_id NAS encryption/integrity algorithm identifier.
* Possible values are:
* - 0 for EIA0 algorithm (Null Integrity Protection algorithm)
* - 1 for 128-EIA1 SNOW 3G
* - 2 for 128-EIA2 AES
* @param[in] kasme Key for MME as provided by AUC
* @param[out] knas Truncated ouput key as derived by KDF
*/
/*int derive_key_nas(algorithm_type_dist_t nas_alg_type, uint8_t nas_enc_alg_id,
const uint8_t kasme[32], uint8_t** knas)
{
uint8_t s[7];
uint8_t knas_temp[32];
// FC
s[0] = 0x15;
// P0 = algorithm type distinguisher
s[1] = nas_alg_type & 0xFF;
// L0 = length(P0) = 1
s[2] = 0x00;
s[3] = 0x01;
// P1
s[4] = nas_enc_alg_id;
// L1 = length(P1) = 1
s[5] = 0x00;
s[6] = 0x01;
kdf(s, 7, (uint8_t*)kasme, 32, (uint8_t**)&knas_temp, 32);
// Truncate the generate key to 128 bits
memcpy(knas, knas_temp, 16);
return 0;
}
*/