1 /* ecc.h - ECDH helpers */ 2 3 /* 4 * Copyright (c) 2016 Intel Corporation 5 * 6 * SPDX-License-Identifier: Apache-2.0 7 */ 8 9 /** Key size used in Bluetooth's ECC domain. */ 10 #define BT_ECC_KEY_SIZE 32 11 /** Length of a Bluetooth ECC public key coordinate. */ 12 #define BT_PUB_KEY_COORD_LEN (BT_ECC_KEY_SIZE) 13 /** Length of a Bluetooth ECC public key. */ 14 #define BT_PUB_KEY_LEN (2 * (BT_PUB_KEY_COORD_LEN)) 15 /** Length of a Bluetooth ECC private key. */ 16 #define BT_PRIV_KEY_LEN (BT_ECC_KEY_SIZE) 17 /** Length of a Bluetooth Diffie-Hellman key. */ 18 #define BT_DH_KEY_LEN (BT_ECC_KEY_SIZE) 19 20 /* @brief Container for public key callback */ 21 struct bt_pub_key_cb { 22 /** @brief Callback type for Public Key generation. 23 * 24 * Used to notify of the local public key or that the local key is not 25 * available (either because of a failure to read it or because it is 26 * being regenerated). 27 * 28 * @param key The local public key, or NULL in case of no key. 29 */ 30 void (*func)(const uint8_t key[BT_PUB_KEY_LEN]); 31 32 /* Internal */ 33 sys_snode_t node; 34 }; 35 36 /* @brief Check if public key is equal to the debug public key. 37 * 38 * Compare the Public key to the Bluetooth specification defined debug public 39 * key. 40 * 41 * @param cmp_pub_key The public key to compare. 42 * 43 * @return True if the public key is the debug public key. 44 */ 45 bool bt_pub_key_is_debug(uint8_t *cmp_pub_key); 46 47 /* @brief Check if public key is valid. 48 * 49 * Verify that the public key is valid, e.g. that its coordinates lie on the eliptic curve. 50 * 51 * @param key The public key to validate. 52 * 53 * @return True if the public key is valid. 54 */ 55 bool bt_pub_key_is_valid(const uint8_t key[BT_PUB_KEY_LEN]); 56 57 /* @brief Generate a new Public Key. 58 * 59 * Generate a new ECC Public Key. Provided cb must persists until callback 60 * is called. Callee adds the callback structure to a linked list. Registering 61 * multiple callbacks requires multiple calls to bt_pub_key_gen() and separate 62 * callback structures. This method cannot be called directly from result 63 * callback. After calling all the registered callbacks the linked list 64 * is cleared. 65 * 66 * @param cb Callback to notify the new key. 67 * 68 * @return Zero on success or negative error code otherwise 69 */ 70 int bt_pub_key_gen(struct bt_pub_key_cb *cb); 71 72 /* @brief Cleanup public key callbacks when HCI is disrupted. 73 * 74 * Clear the pub_key_cb_slist and clear the BT_DEV_PUB_KEY_BUSY flag. 75 */ 76 void bt_pub_key_hci_disrupted(void); 77 78 /* @brief Get the current Public Key. 79 * 80 * Get the current ECC Public Key. 81 * 82 * @return Current key, or NULL if not available. 83 */ 84 const uint8_t *bt_pub_key_get(void); 85 86 /* @typedef bt_dh_key_cb_t 87 * @brief Callback type for DH Key calculation. 88 * 89 * Used to notify of the calculated DH Key. 90 * 91 * @param key The DH Key, or NULL in case of failure. 92 */ 93 typedef void (*bt_dh_key_cb_t)(const uint8_t key[BT_DH_KEY_LEN]); 94 95 /* @brief Calculate a DH Key from a remote Public Key. 96 * 97 * Calculate a DH Key from the remote Public Key. 98 * 99 * @param remote_pk Remote Public Key. 100 * @param cb Callback to notify the calculated key. 101 * 102 * @return Zero on success or negative error code otherwise 103 */ 104 int bt_dh_key_gen(const uint8_t remote_pk[BT_PUB_KEY_LEN], bt_dh_key_cb_t cb); 105
