/** * Copyright (c) 2016 - 2018, Nordic Semiconductor ASA * * All rights reserved. * * Redistribution and use in source and binary forms, with or without modification, * are permitted provided that the following conditions are met: * * 1. Redistributions of source code must retain the above copyright notice, this * list of conditions and the following disclaimer. * * 2. Redistributions in binary form, except as embedded into a Nordic * Semiconductor ASA integrated circuit in a product or a software update for * such product, must reproduce the above copyright notice, this list of * conditions and the following disclaimer in the documentation and/or other * materials provided with the distribution. * * 3. Neither the name of Nordic Semiconductor ASA nor the names of its * contributors may be used to endorse or promote products derived from this * software without specific prior written permission. * * 4. This software, with or without modification, must only be used with a * Nordic Semiconductor ASA integrated circuit. * * 5. Any software provided in binary form under this license must not be reverse * engineered, decompiled, modified and/or disassembled. * * THIS SOFTWARE IS PROVIDED BY NORDIC SEMICONDUCTOR ASA "AS IS" AND ANY EXPRESS * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY, NONINFRINGEMENT, AND FITNESS FOR A PARTICULAR PURPOSE ARE * DISCLAIMED. IN NO EVENT SHALL NORDIC SEMICONDUCTOR ASA OR CONTRIBUTORS BE * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. * */ #ifndef ES_SECURITY_H__ #define ES_SECURITY_H__ #include "app_error.h" #include "nrf_ble_escs.h" /** * @file * @defgroup eddystone_security Security * @brief Types and functions for dealing with security of Eddystone beacons. * @ingroup eddystone * @{ */ /**@brief Security events. */ typedef enum { ES_SECURITY_MSG_UNLOCKED, //!< Beacon is unlocked. ES_SECURITY_MSG_EID, //!< EID has been generated. ES_SECURITY_MSG_IK, //!< IK has been generated. ES_SECURITY_MSG_ECDH, //!< Public ECDH has been generated. ES_SECURITY_MSG_STORE_TIME //!< EID slot time must be stored. } es_security_msg_t; /* @brief Callback for security events. */ typedef void (*es_security_msg_cb_t)(uint8_t slot_no, es_security_msg_t msg_type); /**@brief EID configuration. * * @details This structure is used to preserve or restore an EID slot. * * @note This is a packed structure. Therefore, you should not change it. */ typedef PACKED_STRUCT { es_frame_type_t frame_type; uint8_t k_scaler; uint32_t time_counter; uint8_t ik[ESCS_AES_KEY_SIZE]; } es_eid_config_t; /**@brief Eddystone beacon lock state. */ typedef nrf_ble_escs_lock_state_read_t es_security_lock_state_t; /**@brief Function for initializing the security module. * * @param[in] msg_cb Callback function. * * @return See @ref app_timer_start for possible return values. */ ret_code_t es_security_init(es_security_msg_cb_t msg_cb); /**@brief Function for updating the lock code and storing it to flash. * * @param[in] p_encrypted_key Pointer to the new lock code. * * @return See @ref es_flash_access_lock_key for possible return values. */ ret_code_t es_security_lock_code_update(uint8_t * p_encrypted_key); /**@brief Function for reading the challenge and encrypting it with AES_ECB. * * @details The result of the encryption is compared with the provided unlock token * in @ref es_security_unlock_verify. * * @param[in] p_challenge Pointer to the challenge buffer. * * @return See @ref sd_ecb_block_encrypt for possible return values. */ void es_security_unlock_prepare(uint8_t * p_challenge); /**@brief Function for unlocking the beacon. * * @details This function compares the result from @ref es_security_unlock_prepare to the input * unlock token and unlocks the beacon if matching. * * @param[in] p_unlock_token The unlock token written by the client. */ void es_security_unlock_verify(uint8_t * p_unlock_token); /**@brief Function for generating a random challenge for the unlock characteristic. * * @param[out] p_rand_chlg_buff Pointer to a buffer to which the random challenge is copied. * * @return See @ref sd_rand_application_vector_get for possible return values. */ ret_code_t es_security_random_challenge_generate(uint8_t * p_rand_chlg_buff); /**@brief Function for storing the public ECDH key from the client in the beacon registration process. * * @details This function starts a series of cryptographic activities, including the generation of temporary keys and EIDs. * * @param[in] slot_no The index of the slot whose public ECDH key is retrieved. * @param[in] p_pub_ecdh Pointer to the public ECDH. * @param[in] scaler_k K rotation scaler. */ void es_security_client_pub_ecdh_receive(uint8_t slot_no, uint8_t * p_pub_ecdh, uint8_t scaler_k); /**@brief Function for storing the shared IK from the client in the beacon registration process. * * @details This function starts a series of cryptographic activities, including the generation of temporary keys and EIDs. * * @param[in] slot_no The index of the slot whose public ECDH key is retrieved. * @param[in] p_encrypted_ik Pointer to the received IK. * @param[in] scaler_k K rotation scaler. */ void es_security_shared_ik_receive(uint8_t slot_no, uint8_t * p_encrypted_ik, uint8_t scaler_k); /**@brief Function for copying the 32-byte ECDH key into the provided buffer. * * @param[in] slot_no The index of the slot whose public ECDH key is retrieved. * @param[out] p_edch_buffer Pointer to the buffer. */ void es_security_pub_ecdh_get(uint8_t slot_no, uint8_t * p_edch_buffer); /**@brief Function for returning the beacon clock value (in little endian). * * @param[in] slot_no The index of the slot. * * @return 32-bit clock value. */ uint32_t es_security_clock_get(uint8_t slot_no); /**@brief Function for updating the beacon time counter. * * @details This function checks how much time has passed since the last * invocation and, if required, updates the EID, the temporary key, or both. * The function generates an @ref ES_SECURITY_MSG_STORE_TIME event * for each active security slot every 24 hours. */ void es_security_update_time(void); /**@brief Function for returning the rotation exponent scaler value. * * @param[in] slot_no The index of the slot. * * @return K rotation scaler. */ uint8_t es_security_scaler_get(uint8_t slot_no); /**@brief Function for copying the 8-byte EID into the provided buffer. * * @param[in] slot_no The index of the slot whose EID is retrieved. * @param[out] p_eid_buffer Pointer to the buffer. */ void es_security_eid_get(uint8_t slot_no, uint8_t * p_eid_buffer); /**@brief Function for restoring an EID slot. * * @param[in] slot_no The index of the slot to restore. * @param[in] k_scaler K rotation scaler. * @param[in] time_counter EID slot time counter value (in seconds). * @param[in] p_ik Pointer to the identity key of the specified slot. */ void es_security_eid_slots_restore(uint8_t slot_no, uint8_t k_scaler, uint32_t time_counter, const uint8_t * p_ik); /**@brief Function for destroying stored EID states. * * @details This function should be called when the slot is either overwritten as another slot or * cleared by writing an empty byte or a single 0. * * @param[in] slot_no The index of the slot to destroy. */ void es_security_eid_slot_destroy(uint8_t slot_no); /**@brief Function for copying the 16-byte EID ID key into the provided buffer. * * @param[in] slot_no The index of the EID slot whose IK is retrieved. * @param[out] p_key_buffer Buffer for the key. */ void es_security_plain_eid_id_key_get(uint8_t slot_no, uint8_t * p_key_buffer); /**@brief Function for copying the 16-byte LK encrypted EID ID key into the provided buffer. * * @param[in] slot_no The index of the EID slot whose encrypted IK is retrieved. * @param[out] p_key_buffer Buffer for the key. */ void es_security_encrypted_eid_id_key_get(uint8_t slot_no, uint8_t * p_key_buffer); /**@brief Function for converting a TLM frame into an eTLM frame using the EIK of the specified slot. * * @param[in] ik_slot_no The index of the EID slot whose IK is paired with the eTLM. * @param[in] p_tlm Pointer to the TLM frame buffer. * @param[out] p_etlm Pointer to the eTLM frame buffer. */ void es_security_tlm_to_etlm(uint8_t ik_slot_no, es_tlm_frame_t * p_tlm, es_etlm_frame_t * p_etlm); /** * @} */ #endif // ES_SECURITY_H__