/* * Licensed to the OpenAirInterface (OAI) Software Alliance under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The OpenAirInterface Software Alliance licenses this file to You under * the OAI Public License, Version 1.0 (the "License"); you may not use this file * except in compliance with the License. * You may obtain a copy of the License at * * http://www.openairinterface.org/?page_id=698 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. *------------------------------------------------------------------------------- * For more information about the OpenAirInterface (OAI) Software Alliance: * contact@openairinterface.org */ #include #include #include #include #include "security_types.h" #include "secu_defs.h" void kdf(const uint8_t *key, uint16_t key_len, uint8_t *s, uint16_t s_len, uint8_t *out, uint16_t out_len) { struct hmac_sha256_ctx ctx; memset(&ctx, 0, sizeof(ctx)); hmac_sha256_set_key(&ctx, key_len, key); hmac_sha256_update(&ctx, s_len, s); hmac_sha256_digest(&ctx, out_len, out); } #ifndef NAS_UE int derive_keNB(const uint8_t kasme[32], const uint32_t nas_count, uint8_t *keNB) { uint8_t s[7]; // FC s[0] = FC_KENB; // P0 = Uplink NAS count s[1] = (nas_count & 0xff000000) >> 24; s[2] = (nas_count & 0x00ff0000) >> 16; s[3] = (nas_count & 0x0000ff00) >> 8; s[4] = (nas_count & 0x000000ff); // Length of NAS count s[5] = 0x00; s[6] = 0x04; kdf(kasme, 32, s, 7, keNB, 32); return 0; } #endif int derive_keNB_star ( const uint8_t *kenb_32, const uint16_t pci, const uint32_t earfcn_dl, const bool is_rel8_only, uint8_t *kenb_star) { // see 33.401 section A.5 KeNB* derivation function uint8_t s[10] = {0}; // FC = 0x13 s[0] = FC_KENB_STAR; // P0 = PCI (target physical cell id) s[1] = (pci & 0x0000ff00) >> 8; s[2] = (pci & 0x000000ff); // L0 = length of PCI (i.e. 0x00 0x02) s[3] = 0x00; s[4] = 0x02; // P1 = EARFCN-DL (target physical cell downlink frequency) if (is_rel8_only) { s[5] = (earfcn_dl & 0x0000ff00) >> 8; s[6] = (earfcn_dl & 0x000000ff); s[7] = 0x00; s[8] = 0x02; kdf (kenb_32, 32, s, 9, kenb_star, 32); } else { s[5] = (earfcn_dl & 0x00ff0000) >> 16; s[6] = (earfcn_dl & 0x0000ff00) >> 8; s[7] = (earfcn_dl & 0x000000ff); s[8] = 0x00; s[9] = 0x03; kdf (kenb_32, 32, s, 10, kenb_star, 32); } // L1 length of EARFCN-DL (i.e. L1 = 0x00 0x02 if EARFCN-DL is between 0 and 65535, and L1 = 0x00 0x03 if EARFCN-DL is between 65536 and 262143) // NOTE: The length of EARFCN-DL cannot be generally set to 3 bytes for backward compatibility reasons: A Rel-8 // entity (UE or eNB) would always assume an input parameter length of 2 bytes for the EARFCN-DL. This // would lead to different derived keys if another entity assumed an input parameter length of 3 bytes for the // EARFCN-DL. return 0; }