1 /*
2 * Copyright (c) 2024 Nordic Semiconductor ASA
3 *
4 * SPDX-License-Identifier: Apache-2.0
5 */
6
7 #include <zephyr/kernel.h>
8 #include <zephyr/logging/log.h>
9 #include "psa/crypto.h"
10
11 #include "wifi_credentials_internal.h"
12
13 LOG_MODULE_REGISTER(wifi_credentials_backend, CONFIG_WIFI_CREDENTIALS_LOG_LEVEL);
14
15 #define WIFI_CREDENTIALS_BACKEND_PSA_KEY_ID_USER_MIN \
16 (PSA_KEY_ID_USER_MIN + CONFIG_WIFI_CREDENTIALS_BACKEND_PSA_OFFSET)
17
18 BUILD_ASSERT((WIFI_CREDENTIALS_BACKEND_PSA_KEY_ID_USER_MIN + CONFIG_WIFI_CREDENTIALS_MAX_ENTRIES) <=
19 PSA_KEY_ID_USER_MAX,
20 "WIFI credentials management PSA key id range exceeds PSA_KEY_ID_USER_MAX.");
21
wifi_credentials_backend_init(void)22 int wifi_credentials_backend_init(void)
23 {
24 psa_status_t ret;
25 uint8_t buf[ENTRY_MAX_LEN];
26
27 for (size_t i = 0; i < CONFIG_WIFI_CREDENTIALS_MAX_ENTRIES; ++i) {
28 size_t length_read = 0;
29 size_t key_id = i + WIFI_CREDENTIALS_BACKEND_PSA_KEY_ID_USER_MIN;
30
31 ret = psa_export_key(key_id, buf, ARRAY_SIZE(buf), &length_read);
32 if (ret == PSA_SUCCESS && length_read == ENTRY_MAX_LEN) {
33 wifi_credentials_cache_ssid(i, (struct wifi_credentials_header *)buf);
34 } else if (ret != PSA_ERROR_INVALID_HANDLE) {
35 LOG_ERR("psa_export_key failed, err: %d", ret);
36 return -EFAULT;
37 }
38 }
39
40 return 0;
41 }
42
wifi_credentials_store_entry(size_t idx,const void * buf,size_t buf_len)43 int wifi_credentials_store_entry(size_t idx, const void *buf, size_t buf_len)
44 {
45 psa_status_t ret;
46 psa_key_attributes_t key_attributes = {0};
47 psa_key_id_t key_id;
48
49 psa_set_key_id(&key_attributes, idx + WIFI_CREDENTIALS_BACKEND_PSA_KEY_ID_USER_MIN);
50 psa_set_key_usage_flags(&key_attributes, PSA_KEY_USAGE_EXPORT);
51 psa_set_key_lifetime(&key_attributes, PSA_KEY_LIFETIME_PERSISTENT);
52 psa_set_key_algorithm(&key_attributes, PSA_ALG_NONE);
53 psa_set_key_type(&key_attributes, PSA_KEY_TYPE_RAW_DATA);
54 psa_set_key_bits(&key_attributes, buf_len * 8);
55
56 ret = psa_import_key(&key_attributes, buf, buf_len, &key_id);
57 if (ret == PSA_ERROR_ALREADY_EXISTS) {
58 LOG_ERR("psa_import_key failed, duplicate key: %d", ret);
59 return -EEXIST;
60 } else if (ret != PSA_SUCCESS) {
61 LOG_ERR("psa_import_key failed, err: %d", ret);
62 return -EFAULT;
63 }
64
65 return 0;
66 }
67
wifi_credentials_delete_entry(size_t idx)68 int wifi_credentials_delete_entry(size_t idx)
69 {
70 psa_status_t ret = psa_destroy_key(idx + WIFI_CREDENTIALS_BACKEND_PSA_KEY_ID_USER_MIN);
71
72 if (ret != PSA_SUCCESS) {
73 LOG_ERR("psa_destroy_key failed, err: %d", ret);
74 return -EFAULT;
75 }
76
77 return 0;
78 }
79
wifi_credentials_load_entry(size_t idx,void * buf,size_t buf_len)80 int wifi_credentials_load_entry(size_t idx, void *buf, size_t buf_len)
81 {
82 size_t length_read = 0;
83 size_t key_id = idx + WIFI_CREDENTIALS_BACKEND_PSA_KEY_ID_USER_MIN;
84 psa_status_t ret;
85
86 ret = psa_export_key(key_id, buf, buf_len, &length_read);
87 if (ret != PSA_SUCCESS) {
88 LOG_ERR("psa_export_key failed, err: %d", ret);
89 return -EFAULT;
90 }
91
92 if (buf_len != length_read) {
93 return -EIO;
94 }
95
96 return 0;
97 }
98
