1 /* 2 Copyright (c) 2022 Eriptic Technologies. See the COPYRIGHT 3 file at the top-level directory of this distribution. 4 5 Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or 6 http://www.apache.org/licenses/LICENSE-2.0> or the MIT license 7 <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your 8 option. This file may not be copied, modified, or distributed 9 except according to those terms. 10 */ 11 12 #ifndef NVM_H 13 #define NVM_H 14 15 #include "common/byte_array.h" 16 #include "common/oscore_edhoc_error.h" 17 18 /** 19 * @brief Public fields of the security context which can be used to find the right slot in the NVM. 20 * The usage of given fields is up to user's implementation. 21 * For more details, see nvm_write_ssn and nvm_read_ssn. 22 */ 23 struct nvm_key_t { 24 struct byte_array sender_id; 25 struct byte_array recipient_id; 26 struct byte_array id_context; 27 }; 28 29 #ifdef OSCORE_NVM_SUPPORT 30 /** 31 * @brief When the same OSCORE master secret and salt are reused through 32 * several reboots of the device, e.g., no fresh shared secret is 33 * derived through EDHOC (or some other method) the Sender Sequence 34 * Number MUST be stored periodically in NVM. 35 * @param nvm_key part of the context that is permitted to be used for identifying the right store slot in NVM. 36 * @param ssn SSN to be written in NVM. 37 * @retval ok or error code if storing the SSN was not possible. 38 */ 39 enum err nvm_write_ssn(const struct nvm_key_t *nvm_key, uint64_t ssn); 40 41 /** 42 * @brief When the same OSCORE master secret and salt are reused through 43 * several reboots of the device, e.g., no fresh shared secret is 44 * derived through EDHOC (or some other method) the Sender Sequence 45 * Number MUST be restored from NVM at each reboot. 46 * @param nvm_key part of the context that is permitted to be used for identifying the right store slot in NVM. 47 * @param ssn SSN to be read out from NVM. 48 * @retval ok or error code if the retrieving the SSN was not possible. 49 */ 50 enum err nvm_read_ssn(const struct nvm_key_t *nvm_key, uint64_t *ssn); 51 52 /** 53 * @brief Periodically stores the SSN in NVM (if needed). 54 * 55 * @param nvm_key part of the context that is permitted to be used for identifying the right store slot in NVM. 56 * @param ssn SSN to be written in NVM. 57 * @param echo_sync_in_progress Indicates if the device is still in the ECHO synchronization mode. 58 * @return enum err 59 */ 60 enum err ssn_store_in_nvm(const struct nvm_key_t *nvm_key, uint64_t ssn, 61 bool echo_sync_in_progress); 62 #endif 63 64 /** 65 * @brief Initializes the SSN depending on context freshness. 66 * @param nvm_key part of the context that is permitted to be used for identifying the right store slot in NVM. 67 * @param ssn Pointer which will be updated with the value read from NVM. 68 * @param is_context_fresh Indicates if the context is fresh, or the value needs to be retrieved from NVM. 69 * @retval error code 70 */ 71 enum err ssn_init(const struct nvm_key_t *nvm_key, uint64_t *ssn, 72 bool is_context_fresh); 73 74 #endif 75
