| /* keys.c - Bluetooth key handling */ |
| |
| /* |
| * Copyright (c) 2015-2016 Intel Corporation |
| * |
| * SPDX-License-Identifier: Apache-2.0 |
| */ |
| |
| #include <zephyr.h> |
| #include <string.h> |
| #include <stdlib.h> |
| #include <sys/atomic.h> |
| #include <sys/util.h> |
| |
| #include <settings/settings.h> |
| |
| #include <bluetooth/bluetooth.h> |
| #include <bluetooth/conn.h> |
| #include <bluetooth/hci.h> |
| |
| #define BT_DBG_ENABLED IS_ENABLED(CONFIG_BT_DEBUG_KEYS) |
| #define LOG_MODULE_NAME bt_keys |
| #include "common/log.h" |
| |
| #include "common/rpa.h" |
| #include "gatt_internal.h" |
| #include "hci_core.h" |
| #include "smp.h" |
| #include "settings.h" |
| #include "keys.h" |
| |
| static struct bt_keys key_pool[CONFIG_BT_MAX_PAIRED]; |
| |
| #define BT_KEYS_STORAGE_LEN_COMPAT (BT_KEYS_STORAGE_LEN - sizeof(uint32_t)) |
| |
| #if IS_ENABLED(CONFIG_BT_KEYS_OVERWRITE_OLDEST) |
| static u32_t aging_counter_val; |
| static struct bt_keys *last_keys_updated; |
| #endif /* CONFIG_BT_KEYS_OVERWRITE_OLDEST */ |
| |
| struct bt_keys *bt_keys_get_addr(u8_t id, const bt_addr_le_t *addr) |
| { |
| struct bt_keys *keys; |
| int i; |
| size_t first_free_slot = ARRAY_SIZE(key_pool); |
| |
| BT_DBG("%s", bt_addr_le_str(addr)); |
| |
| for (i = 0; i < ARRAY_SIZE(key_pool); i++) { |
| keys = &key_pool[i]; |
| |
| if (keys->id == id && !bt_addr_le_cmp(&keys->addr, addr)) { |
| return keys; |
| } |
| |
| if (first_free_slot == ARRAY_SIZE(key_pool) && |
| !bt_addr_le_cmp(&keys->addr, BT_ADDR_LE_ANY)) { |
| first_free_slot = i; |
| } |
| } |
| |
| #if IS_ENABLED(CONFIG_BT_KEYS_OVERWRITE_OLDEST) |
| if (first_free_slot == ARRAY_SIZE(key_pool)) { |
| struct bt_keys *oldest = &key_pool[0]; |
| |
| for (i = 1; i < ARRAY_SIZE(key_pool); i++) { |
| struct bt_keys *current = &key_pool[i]; |
| |
| if (current->aging_counter < oldest->aging_counter) { |
| oldest = current; |
| } |
| } |
| |
| bt_unpair(oldest->id, &oldest->addr); |
| if (!bt_addr_le_cmp(&oldest->addr, BT_ADDR_LE_ANY)) { |
| first_free_slot = oldest - &key_pool[0]; |
| } |
| } |
| |
| #endif /* CONFIG_BT_KEYS_OVERWRITE_OLDEST */ |
| if (first_free_slot < ARRAY_SIZE(key_pool)) { |
| keys = &key_pool[first_free_slot]; |
| keys->id = id; |
| bt_addr_le_copy(&keys->addr, addr); |
| #if IS_ENABLED(CONFIG_BT_KEYS_OVERWRITE_OLDEST) |
| keys->aging_counter = ++aging_counter_val; |
| last_keys_updated = keys; |
| #endif /* CONFIG_BT_KEYS_OVERWRITE_OLDEST */ |
| BT_DBG("created %p for %s", keys, bt_addr_le_str(addr)); |
| return keys; |
| } |
| |
| BT_DBG("unable to create keys for %s", bt_addr_le_str(addr)); |
| |
| return NULL; |
| } |
| |
| void bt_foreach_bond(u8_t id, void (*func)(const struct bt_bond_info *info, |
| void *user_data), |
| void *user_data) |
| { |
| int i; |
| |
| for (i = 0; i < ARRAY_SIZE(key_pool); i++) { |
| struct bt_keys *keys = &key_pool[i]; |
| |
| if (keys->keys && keys->id == id) { |
| struct bt_bond_info info; |
| |
| bt_addr_le_copy(&info.addr, &keys->addr); |
| func(&info, user_data); |
| } |
| } |
| } |
| |
| void bt_keys_foreach(int type, void (*func)(struct bt_keys *keys, void *data), |
| void *data) |
| { |
| int i; |
| |
| for (i = 0; i < ARRAY_SIZE(key_pool); i++) { |
| if ((key_pool[i].keys & type)) { |
| func(&key_pool[i], data); |
| } |
| } |
| } |
| |
| struct bt_keys *bt_keys_find(int type, u8_t id, const bt_addr_le_t *addr) |
| { |
| int i; |
| |
| BT_DBG("type %d %s", type, bt_addr_le_str(addr)); |
| |
| for (i = 0; i < ARRAY_SIZE(key_pool); i++) { |
| if ((key_pool[i].keys & type) && key_pool[i].id == id && |
| !bt_addr_le_cmp(&key_pool[i].addr, addr)) { |
| return &key_pool[i]; |
| } |
| } |
| |
| return NULL; |
| } |
| |
| struct bt_keys *bt_keys_get_type(int type, u8_t id, const bt_addr_le_t *addr) |
| { |
| struct bt_keys *keys; |
| |
| BT_DBG("type %d %s", type, bt_addr_le_str(addr)); |
| |
| keys = bt_keys_find(type, id, addr); |
| if (keys) { |
| return keys; |
| } |
| |
| keys = bt_keys_get_addr(id, addr); |
| if (!keys) { |
| return NULL; |
| } |
| |
| bt_keys_add_type(keys, type); |
| |
| return keys; |
| } |
| |
| struct bt_keys *bt_keys_find_irk(u8_t id, const bt_addr_le_t *addr) |
| { |
| int i; |
| |
| BT_DBG("%s", bt_addr_le_str(addr)); |
| |
| if (!bt_addr_le_is_rpa(addr)) { |
| return NULL; |
| } |
| |
| for (i = 0; i < ARRAY_SIZE(key_pool); i++) { |
| if (!(key_pool[i].keys & BT_KEYS_IRK)) { |
| continue; |
| } |
| |
| if (key_pool[i].id == id && |
| !bt_addr_cmp(&addr->a, &key_pool[i].irk.rpa)) { |
| BT_DBG("cached RPA %s for %s", |
| bt_addr_str(&key_pool[i].irk.rpa), |
| bt_addr_le_str(&key_pool[i].addr)); |
| return &key_pool[i]; |
| } |
| } |
| |
| for (i = 0; i < ARRAY_SIZE(key_pool); i++) { |
| if (!(key_pool[i].keys & BT_KEYS_IRK)) { |
| continue; |
| } |
| |
| if (key_pool[i].id != id) { |
| continue; |
| } |
| |
| if (bt_rpa_irk_matches(key_pool[i].irk.val, &addr->a)) { |
| BT_DBG("RPA %s matches %s", |
| bt_addr_str(&key_pool[i].irk.rpa), |
| bt_addr_le_str(&key_pool[i].addr)); |
| |
| bt_addr_copy(&key_pool[i].irk.rpa, &addr->a); |
| |
| return &key_pool[i]; |
| } |
| } |
| |
| BT_DBG("No IRK for %s", bt_addr_le_str(addr)); |
| |
| return NULL; |
| } |
| |
| struct bt_keys *bt_keys_find_addr(u8_t id, const bt_addr_le_t *addr) |
| { |
| int i; |
| |
| BT_DBG("%s", bt_addr_le_str(addr)); |
| |
| for (i = 0; i < ARRAY_SIZE(key_pool); i++) { |
| if (key_pool[i].id == id && |
| !bt_addr_le_cmp(&key_pool[i].addr, addr)) { |
| return &key_pool[i]; |
| } |
| } |
| |
| return NULL; |
| } |
| |
| void bt_keys_add_type(struct bt_keys *keys, int type) |
| { |
| keys->keys |= type; |
| } |
| |
| void bt_keys_clear(struct bt_keys *keys) |
| { |
| BT_DBG("%s (keys 0x%04x)", bt_addr_le_str(&keys->addr), keys->keys); |
| |
| if (keys->state & BT_KEYS_ID_ADDED) { |
| bt_id_del(keys); |
| } |
| |
| if (IS_ENABLED(CONFIG_BT_SETTINGS)) { |
| char key[BT_SETTINGS_KEY_MAX]; |
| |
| /* Delete stored keys from flash */ |
| if (keys->id) { |
| char id[4]; |
| |
| u8_to_dec(id, sizeof(id), keys->id); |
| bt_settings_encode_key(key, sizeof(key), "keys", |
| &keys->addr, id); |
| } else { |
| bt_settings_encode_key(key, sizeof(key), "keys", |
| &keys->addr, NULL); |
| } |
| |
| BT_DBG("Deleting key %s", log_strdup(key)); |
| settings_delete(key); |
| } |
| |
| (void)memset(keys, 0, sizeof(*keys)); |
| } |
| |
| #if defined(CONFIG_BT_SETTINGS) |
| int bt_keys_store(struct bt_keys *keys) |
| { |
| char key[BT_SETTINGS_KEY_MAX]; |
| int err; |
| |
| if (keys->id) { |
| char id[4]; |
| |
| u8_to_dec(id, sizeof(id), keys->id); |
| bt_settings_encode_key(key, sizeof(key), "keys", &keys->addr, |
| id); |
| } else { |
| bt_settings_encode_key(key, sizeof(key), "keys", &keys->addr, |
| NULL); |
| } |
| |
| err = settings_save_one(key, keys->storage_start, BT_KEYS_STORAGE_LEN); |
| if (err) { |
| BT_ERR("Failed to save keys (err %d)", err); |
| return err; |
| } |
| |
| BT_DBG("Stored keys for %s (%s)", bt_addr_le_str(&keys->addr), |
| log_strdup(key)); |
| |
| return 0; |
| } |
| |
| static int keys_set(const char *name, size_t len_rd, settings_read_cb read_cb, |
| void *cb_arg) |
| { |
| struct bt_keys *keys; |
| bt_addr_le_t addr; |
| u8_t id; |
| ssize_t len; |
| int err; |
| char val[BT_KEYS_STORAGE_LEN]; |
| const char *next; |
| |
| if (!name) { |
| BT_ERR("Insufficient number of arguments"); |
| return -EINVAL; |
| } |
| |
| len = read_cb(cb_arg, val, sizeof(val)); |
| if (len < 0) { |
| BT_ERR("Failed to read value (err %zd)", len); |
| return -EINVAL; |
| } |
| |
| BT_DBG("name %s val %s", log_strdup(name), |
| (len) ? bt_hex(val, sizeof(val)) : "(null)"); |
| |
| err = bt_settings_decode_key(name, &addr); |
| if (err) { |
| BT_ERR("Unable to decode address %s", name); |
| return -EINVAL; |
| } |
| |
| settings_name_next(name, &next); |
| |
| if (!next) { |
| id = BT_ID_DEFAULT; |
| } else { |
| id = strtol(next, NULL, 10); |
| } |
| |
| if (!len) { |
| keys = bt_keys_find(BT_KEYS_ALL, id, &addr); |
| if (keys) { |
| (void)memset(keys, 0, sizeof(*keys)); |
| BT_DBG("Cleared keys for %s", bt_addr_le_str(&addr)); |
| } else { |
| BT_WARN("Unable to find deleted keys for %s", |
| bt_addr_le_str(&addr)); |
| } |
| |
| return 0; |
| } |
| |
| keys = bt_keys_get_addr(id, &addr); |
| if (!keys) { |
| BT_ERR("Failed to allocate keys for %s", bt_addr_le_str(&addr)); |
| return -ENOMEM; |
| } |
| if (len != BT_KEYS_STORAGE_LEN) { |
| do { |
| /* Load shorter structure for compatibility with old |
| * records format with no counter. |
| */ |
| if (IS_ENABLED(CONFIG_BT_KEYS_OVERWRITE_OLDEST) && |
| len == BT_KEYS_STORAGE_LEN_COMPAT) { |
| BT_WARN("Keys for %s have no aging counter", |
| bt_addr_le_str(&addr)); |
| memcpy(keys->storage_start, val, len); |
| continue; |
| } |
| |
| BT_ERR("Invalid key length %zd != %zu", len, |
| BT_KEYS_STORAGE_LEN); |
| bt_keys_clear(keys); |
| |
| return -EINVAL; |
| } while (0); |
| } else { |
| memcpy(keys->storage_start, val, len); |
| } |
| |
| BT_DBG("Successfully restored keys for %s", bt_addr_le_str(&addr)); |
| #if IS_ENABLED(CONFIG_BT_KEYS_OVERWRITE_OLDEST) |
| if (aging_counter_val < keys->aging_counter) { |
| aging_counter_val = keys->aging_counter; |
| } |
| #endif /* CONFIG_BT_KEYS_OVERWRITE_OLDEST */ |
| return 0; |
| } |
| |
| static void id_add(struct bt_keys *keys, void *user_data) |
| { |
| bt_id_add(keys); |
| } |
| |
| static int keys_commit(void) |
| { |
| BT_DBG(""); |
| |
| /* We do this in commit() rather than add() since add() may get |
| * called multiple times for the same address, especially if |
| * the keys were already removed. |
| */ |
| if (IS_ENABLED(CONFIG_BT_CENTRAL) && IS_ENABLED(CONFIG_BT_PRIVACY)) { |
| bt_keys_foreach(BT_KEYS_ALL, id_add, NULL); |
| } else { |
| bt_keys_foreach(BT_KEYS_IRK, id_add, NULL); |
| } |
| |
| return 0; |
| } |
| |
| SETTINGS_STATIC_HANDLER_DEFINE(bt_keys, "bt/keys", NULL, keys_set, keys_commit, |
| NULL); |
| |
| #endif /* CONFIG_BT_SETTINGS */ |
| |
| #if IS_ENABLED(CONFIG_BT_KEYS_OVERWRITE_OLDEST) |
| void bt_keys_update_usage(u8_t id, const bt_addr_le_t *addr) |
| { |
| struct bt_keys *keys = bt_keys_find_addr(id, addr); |
| |
| if (!keys) { |
| return; |
| } |
| |
| if (last_keys_updated == keys) { |
| return; |
| } |
| |
| keys->aging_counter = ++aging_counter_val; |
| last_keys_updated = keys; |
| |
| BT_DBG("Aging counter for %s is set to %u", bt_addr_le_str(addr), |
| keys->aging_counter); |
| |
| if (IS_ENABLED(CONFIG_BT_KEYS_SAVE_AGING_COUNTER_ON_PAIRING)) { |
| bt_keys_store(keys); |
| } |
| } |
| |
| #endif /* CONFIG_BT_KEYS_OVERWRITE_OLDEST */ |