xref: /linux/drivers/net/wireless/silabs/wfx/key.c (revision 4f2c0a4acffbec01079c28f839422e64ddeff004)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Key management related functions.
4  *
5  * Copyright (c) 2017-2020, Silicon Laboratories, Inc.
6  * Copyright (c) 2010, ST-Ericsson
7  */
8 #include <linux/etherdevice.h>
9 #include <net/mac80211.h>
10 
11 #include "key.h"
12 #include "wfx.h"
13 #include "hif_tx_mib.h"
14 
wfx_alloc_key(struct wfx_dev * wdev)15 static int wfx_alloc_key(struct wfx_dev *wdev)
16 {
17 	int idx;
18 
19 	idx = ffs(~wdev->key_map) - 1;
20 	if (idx < 0 || idx >= MAX_KEY_ENTRIES)
21 		return -1;
22 
23 	wdev->key_map |= BIT(idx);
24 	return idx;
25 }
26 
wfx_free_key(struct wfx_dev * wdev,int idx)27 static void wfx_free_key(struct wfx_dev *wdev, int idx)
28 {
29 	WARN(!(wdev->key_map & BIT(idx)), "inconsistent key allocation");
30 	wdev->key_map &= ~BIT(idx);
31 }
32 
fill_wep_pair(struct wfx_hif_wep_pairwise_key * msg,struct ieee80211_key_conf * key,u8 * peer_addr)33 static u8 fill_wep_pair(struct wfx_hif_wep_pairwise_key *msg,
34 			struct ieee80211_key_conf *key, u8 *peer_addr)
35 {
36 	WARN(key->keylen > sizeof(msg->key_data), "inconsistent data");
37 	msg->key_length = key->keylen;
38 	memcpy(msg->key_data, key->key, key->keylen);
39 	ether_addr_copy(msg->peer_address, peer_addr);
40 	return HIF_KEY_TYPE_WEP_PAIRWISE;
41 }
42 
fill_wep_group(struct wfx_hif_wep_group_key * msg,struct ieee80211_key_conf * key)43 static u8 fill_wep_group(struct wfx_hif_wep_group_key *msg,
44 			 struct ieee80211_key_conf *key)
45 {
46 	WARN(key->keylen > sizeof(msg->key_data), "inconsistent data");
47 	msg->key_id = key->keyidx;
48 	msg->key_length = key->keylen;
49 	memcpy(msg->key_data, key->key, key->keylen);
50 	return HIF_KEY_TYPE_WEP_DEFAULT;
51 }
52 
fill_tkip_pair(struct wfx_hif_tkip_pairwise_key * msg,struct ieee80211_key_conf * key,u8 * peer_addr)53 static u8 fill_tkip_pair(struct wfx_hif_tkip_pairwise_key *msg,
54 			 struct ieee80211_key_conf *key, u8 *peer_addr)
55 {
56 	u8 *keybuf = key->key;
57 
58 	WARN(key->keylen != sizeof(msg->tkip_key_data) + sizeof(msg->tx_mic_key) +
59 			    sizeof(msg->rx_mic_key), "inconsistent data");
60 	memcpy(msg->tkip_key_data, keybuf, sizeof(msg->tkip_key_data));
61 	keybuf += sizeof(msg->tkip_key_data);
62 	memcpy(msg->tx_mic_key, keybuf, sizeof(msg->tx_mic_key));
63 	keybuf += sizeof(msg->tx_mic_key);
64 	memcpy(msg->rx_mic_key, keybuf, sizeof(msg->rx_mic_key));
65 	ether_addr_copy(msg->peer_address, peer_addr);
66 	return HIF_KEY_TYPE_TKIP_PAIRWISE;
67 }
68 
fill_tkip_group(struct wfx_hif_tkip_group_key * msg,struct ieee80211_key_conf * key,struct ieee80211_key_seq * seq,enum nl80211_iftype iftype)69 static u8 fill_tkip_group(struct wfx_hif_tkip_group_key *msg, struct ieee80211_key_conf *key,
70 			  struct ieee80211_key_seq *seq, enum nl80211_iftype iftype)
71 {
72 	u8 *keybuf = key->key;
73 
74 	WARN(key->keylen != sizeof(msg->tkip_key_data) + 2 * sizeof(msg->rx_mic_key),
75 	     "inconsistent data");
76 	msg->key_id = key->keyidx;
77 	memcpy(msg->rx_sequence_counter, &seq->tkip.iv16, sizeof(seq->tkip.iv16));
78 	memcpy(msg->rx_sequence_counter + sizeof(u16), &seq->tkip.iv32, sizeof(seq->tkip.iv32));
79 	memcpy(msg->tkip_key_data, keybuf, sizeof(msg->tkip_key_data));
80 	keybuf += sizeof(msg->tkip_key_data);
81 	if (iftype == NL80211_IFTYPE_AP)
82 		/* Use Tx MIC Key */
83 		memcpy(msg->rx_mic_key, keybuf + 0, sizeof(msg->rx_mic_key));
84 	else
85 		/* Use Rx MIC Key */
86 		memcpy(msg->rx_mic_key, keybuf + 8, sizeof(msg->rx_mic_key));
87 	return HIF_KEY_TYPE_TKIP_GROUP;
88 }
89 
fill_ccmp_pair(struct wfx_hif_aes_pairwise_key * msg,struct ieee80211_key_conf * key,u8 * peer_addr)90 static u8 fill_ccmp_pair(struct wfx_hif_aes_pairwise_key *msg,
91 			 struct ieee80211_key_conf *key, u8 *peer_addr)
92 {
93 	WARN(key->keylen != sizeof(msg->aes_key_data), "inconsistent data");
94 	ether_addr_copy(msg->peer_address, peer_addr);
95 	memcpy(msg->aes_key_data, key->key, key->keylen);
96 	return HIF_KEY_TYPE_AES_PAIRWISE;
97 }
98 
fill_ccmp_group(struct wfx_hif_aes_group_key * msg,struct ieee80211_key_conf * key,struct ieee80211_key_seq * seq)99 static u8 fill_ccmp_group(struct wfx_hif_aes_group_key *msg,
100 			  struct ieee80211_key_conf *key, struct ieee80211_key_seq *seq)
101 {
102 	WARN(key->keylen != sizeof(msg->aes_key_data), "inconsistent data");
103 	memcpy(msg->aes_key_data, key->key, key->keylen);
104 	memcpy(msg->rx_sequence_counter, seq->ccmp.pn, sizeof(seq->ccmp.pn));
105 	memreverse(msg->rx_sequence_counter, sizeof(seq->ccmp.pn));
106 	msg->key_id = key->keyidx;
107 	return HIF_KEY_TYPE_AES_GROUP;
108 }
109 
fill_sms4_pair(struct wfx_hif_wapi_pairwise_key * msg,struct ieee80211_key_conf * key,u8 * peer_addr)110 static u8 fill_sms4_pair(struct wfx_hif_wapi_pairwise_key *msg,
111 			 struct ieee80211_key_conf *key, u8 *peer_addr)
112 {
113 	u8 *keybuf = key->key;
114 
115 	WARN(key->keylen != sizeof(msg->wapi_key_data) + sizeof(msg->mic_key_data),
116 	     "inconsistent data");
117 	ether_addr_copy(msg->peer_address, peer_addr);
118 	memcpy(msg->wapi_key_data, keybuf, sizeof(msg->wapi_key_data));
119 	keybuf += sizeof(msg->wapi_key_data);
120 	memcpy(msg->mic_key_data, keybuf, sizeof(msg->mic_key_data));
121 	msg->key_id = key->keyidx;
122 	return HIF_KEY_TYPE_WAPI_PAIRWISE;
123 }
124 
fill_sms4_group(struct wfx_hif_wapi_group_key * msg,struct ieee80211_key_conf * key)125 static u8 fill_sms4_group(struct wfx_hif_wapi_group_key *msg,
126 			  struct ieee80211_key_conf *key)
127 {
128 	u8 *keybuf = key->key;
129 
130 	WARN(key->keylen != sizeof(msg->wapi_key_data) + sizeof(msg->mic_key_data),
131 	     "inconsistent data");
132 	memcpy(msg->wapi_key_data, keybuf, sizeof(msg->wapi_key_data));
133 	keybuf += sizeof(msg->wapi_key_data);
134 	memcpy(msg->mic_key_data, keybuf, sizeof(msg->mic_key_data));
135 	msg->key_id = key->keyidx;
136 	return HIF_KEY_TYPE_WAPI_GROUP;
137 }
138 
fill_aes_cmac_group(struct wfx_hif_igtk_group_key * msg,struct ieee80211_key_conf * key,struct ieee80211_key_seq * seq)139 static u8 fill_aes_cmac_group(struct wfx_hif_igtk_group_key *msg,
140 			      struct ieee80211_key_conf *key, struct ieee80211_key_seq *seq)
141 {
142 	WARN(key->keylen != sizeof(msg->igtk_key_data), "inconsistent data");
143 	memcpy(msg->igtk_key_data, key->key, key->keylen);
144 	memcpy(msg->ipn, seq->aes_cmac.pn, sizeof(seq->aes_cmac.pn));
145 	memreverse(msg->ipn, sizeof(seq->aes_cmac.pn));
146 	msg->key_id = key->keyidx;
147 	return HIF_KEY_TYPE_IGTK_GROUP;
148 }
149 
wfx_add_key(struct wfx_vif * wvif,struct ieee80211_sta * sta,struct ieee80211_key_conf * key)150 static int wfx_add_key(struct wfx_vif *wvif, struct ieee80211_sta *sta,
151 		       struct ieee80211_key_conf *key)
152 {
153 	int ret;
154 	struct wfx_hif_req_add_key k = { };
155 	struct ieee80211_key_seq seq;
156 	struct wfx_dev *wdev = wvif->wdev;
157 	int idx = wfx_alloc_key(wvif->wdev);
158 	bool pairwise = key->flags & IEEE80211_KEY_FLAG_PAIRWISE;
159 	struct ieee80211_vif *vif = wvif_to_vif(wvif);
160 
161 	WARN(key->flags & IEEE80211_KEY_FLAG_PAIRWISE && !sta, "inconsistent data");
162 	ieee80211_get_key_rx_seq(key, 0, &seq);
163 	if (idx < 0)
164 		return -EINVAL;
165 	k.int_id = wvif->id;
166 	k.entry_index = idx;
167 	if (key->cipher == WLAN_CIPHER_SUITE_WEP40 ||
168 	    key->cipher == WLAN_CIPHER_SUITE_WEP104) {
169 		if (pairwise)
170 			k.type = fill_wep_pair(&k.key.wep_pairwise_key, key, sta->addr);
171 		else
172 			k.type = fill_wep_group(&k.key.wep_group_key, key);
173 	} else if (key->cipher == WLAN_CIPHER_SUITE_TKIP) {
174 		if (pairwise)
175 			k.type = fill_tkip_pair(&k.key.tkip_pairwise_key, key, sta->addr);
176 		else
177 			k.type = fill_tkip_group(&k.key.tkip_group_key, key, &seq,
178 						 vif->type);
179 	} else if (key->cipher == WLAN_CIPHER_SUITE_CCMP) {
180 		if (pairwise)
181 			k.type = fill_ccmp_pair(&k.key.aes_pairwise_key, key, sta->addr);
182 		else
183 			k.type = fill_ccmp_group(&k.key.aes_group_key, key, &seq);
184 	} else if (key->cipher == WLAN_CIPHER_SUITE_SMS4) {
185 		if (pairwise)
186 			k.type = fill_sms4_pair(&k.key.wapi_pairwise_key, key, sta->addr);
187 		else
188 			k.type = fill_sms4_group(&k.key.wapi_group_key, key);
189 	} else if (key->cipher == WLAN_CIPHER_SUITE_AES_CMAC) {
190 		k.type = fill_aes_cmac_group(&k.key.igtk_group_key, key, &seq);
191 		key->flags |= IEEE80211_KEY_FLAG_GENERATE_MMIE;
192 	} else {
193 		dev_warn(wdev->dev, "unsupported key type %d\n", key->cipher);
194 		wfx_free_key(wdev, idx);
195 		return -EOPNOTSUPP;
196 	}
197 	ret = wfx_hif_add_key(wdev, &k);
198 	if (ret) {
199 		wfx_free_key(wdev, idx);
200 		return -EOPNOTSUPP;
201 	}
202 	key->flags |= IEEE80211_KEY_FLAG_PUT_IV_SPACE | IEEE80211_KEY_FLAG_RESERVE_TAILROOM;
203 	key->hw_key_idx = idx;
204 	return 0;
205 }
206 
wfx_remove_key(struct wfx_vif * wvif,struct ieee80211_key_conf * key)207 static int wfx_remove_key(struct wfx_vif *wvif, struct ieee80211_key_conf *key)
208 {
209 	WARN(key->hw_key_idx >= MAX_KEY_ENTRIES, "corrupted hw_key_idx");
210 	wfx_free_key(wvif->wdev, key->hw_key_idx);
211 	return wfx_hif_remove_key(wvif->wdev, key->hw_key_idx);
212 }
213 
wfx_set_key(struct ieee80211_hw * hw,enum set_key_cmd cmd,struct ieee80211_vif * vif,struct ieee80211_sta * sta,struct ieee80211_key_conf * key)214 int wfx_set_key(struct ieee80211_hw *hw, enum set_key_cmd cmd, struct ieee80211_vif *vif,
215 		struct ieee80211_sta *sta, struct ieee80211_key_conf *key)
216 {
217 	int ret = -EOPNOTSUPP;
218 	struct wfx_vif *wvif = (struct wfx_vif *)vif->drv_priv;
219 
220 	mutex_lock(&wvif->wdev->conf_mutex);
221 	if (cmd == SET_KEY)
222 		ret = wfx_add_key(wvif, sta, key);
223 	if (cmd == DISABLE_KEY)
224 		ret = wfx_remove_key(wvif, key);
225 	mutex_unlock(&wvif->wdev->conf_mutex);
226 	return ret;
227 }
228