return 0;
}
+
+
+
+static int llsec_recover_addr(struct mac802154_llsec *sec,
+ struct ieee802154_addr *addr)
+{
+ __le16 caddr = sec->params.coord_shortaddr;
+ addr->pan_id = sec->params.pan_id;
+
+ if (caddr == cpu_to_le16(IEEE802154_ADDR_BROADCAST)) {
+ return -EINVAL;
+ } else if (caddr == cpu_to_le16(IEEE802154_ADDR_UNDEF)) {
+ addr->extended_addr = sec->params.coord_hwaddr;
+ addr->mode = IEEE802154_ADDR_LONG;
+ } else {
+ addr->short_addr = sec->params.coord_shortaddr;
+ addr->mode = IEEE802154_ADDR_SHORT;
+ }
+
+ return 0;
+}
+
+static struct mac802154_llsec_key*
+llsec_lookup_key(struct mac802154_llsec *sec,
+ const struct ieee802154_hdr *hdr,
+ const struct ieee802154_addr *addr,
+ struct ieee802154_llsec_key_id *key_id)
+{
+ struct ieee802154_addr devaddr = *addr;
+ u8 key_id_mode = hdr->sec.key_id_mode;
+ struct ieee802154_llsec_key_entry *key_entry;
+ struct mac802154_llsec_key *key;
+
+ if (key_id_mode == IEEE802154_SCF_KEY_IMPLICIT &&
+ devaddr.mode == IEEE802154_ADDR_NONE) {
+ if (hdr->fc.type == IEEE802154_FC_TYPE_BEACON) {
+ devaddr.extended_addr = sec->params.coord_hwaddr;
+ devaddr.mode = IEEE802154_ADDR_LONG;
+ } else if (llsec_recover_addr(sec, &devaddr) < 0) {
+ return NULL;
+ }
+ }
+
+ list_for_each_entry_rcu(key_entry, &sec->table.keys, list) {
+ const struct ieee802154_llsec_key_id *id = &key_entry->id;
+
+ if (!(key_entry->key->frame_types & BIT(hdr->fc.type)))
+ continue;
+
+ if (id->mode != key_id_mode)
+ continue;
+
+ if (key_id_mode == IEEE802154_SCF_KEY_IMPLICIT) {
+ if (ieee802154_addr_equal(&devaddr, &id->device_addr))
+ goto found;
+ } else {
+ if (id->id != hdr->sec.key_id)
+ continue;
+
+ if ((key_id_mode == IEEE802154_SCF_KEY_INDEX) ||
+ (key_id_mode == IEEE802154_SCF_KEY_SHORT_INDEX &&
+ id->short_source == hdr->sec.short_src) ||
+ (key_id_mode == IEEE802154_SCF_KEY_HW_INDEX &&
+ id->extended_source == hdr->sec.extended_src))
+ goto found;
+ }
+ }
+
+ return NULL;
+
+found:
+ key = container_of(key_entry->key, struct mac802154_llsec_key, key);
+ if (key_id)
+ *key_id = key_entry->id;
+ return llsec_key_get(key);
+}
+
+
+static void llsec_geniv(u8 iv[16], __le64 addr,
+ const struct ieee802154_sechdr *sec)
+{
+ __be64 addr_bytes = (__force __be64) swab64((__force u64) addr);
+ __be32 frame_counter = (__force __be32) swab32((__force u32) sec->frame_counter);
+
+ iv[0] = 1; /* L' = L - 1 = 1 */
+ memcpy(iv + 1, &addr_bytes, sizeof(addr_bytes));
+ memcpy(iv + 9, &frame_counter, sizeof(frame_counter));
+ iv[13] = sec->level;
+ iv[14] = 0;
+ iv[15] = 1;
+}
+
+static int
+llsec_do_encrypt_unauth(struct sk_buff *skb, const struct mac802154_llsec *sec,
+ const struct ieee802154_hdr *hdr,
+ struct mac802154_llsec_key *key)
+{
+ u8 iv[16];
+ struct scatterlist src;
+ struct blkcipher_desc req = {
+ .tfm = key->tfm0,
+ .info = iv,
+ .flags = 0,
+ };
+
+ llsec_geniv(iv, sec->params.hwaddr, &hdr->sec);
+ sg_init_one(&src, skb->data, skb->len);
+ return crypto_blkcipher_encrypt_iv(&req, &src, &src, skb->len);
+}
+
+static struct crypto_aead*
+llsec_tfm_by_len(struct mac802154_llsec_key *key, int authlen)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(key->tfm); i++)
+ if (crypto_aead_authsize(key->tfm[i]) == authlen)
+ return key->tfm[i];
+
+ BUG();
+}
+
+static int
+llsec_do_encrypt_auth(struct sk_buff *skb, const struct mac802154_llsec *sec,
+ const struct ieee802154_hdr *hdr,
+ struct mac802154_llsec_key *key)
+{
+ u8 iv[16];
+ unsigned char *data;
+ int authlen, assoclen, datalen, rc;
+ struct scatterlist src, assoc[2], dst[2];
+ struct aead_request *req;
+
+ authlen = ieee802154_sechdr_authtag_len(&hdr->sec);
+ llsec_geniv(iv, sec->params.hwaddr, &hdr->sec);
+
+ req = aead_request_alloc(llsec_tfm_by_len(key, authlen), GFP_ATOMIC);
+ if (!req)
+ return -ENOMEM;
+
+ sg_init_table(assoc, 2);
+ sg_set_buf(&assoc[0], skb_mac_header(skb), skb->mac_len);
+ assoclen = skb->mac_len;
+
+ data = skb_mac_header(skb) + skb->mac_len;
+ datalen = skb_tail_pointer(skb) - data;
+
+ if (hdr->sec.level & IEEE802154_SCF_SECLEVEL_ENC) {
+ sg_set_buf(&assoc[1], data, 0);
+ } else {
+ sg_set_buf(&assoc[1], data, datalen);
+ assoclen += datalen;
+ datalen = 0;
+ }
+
+ sg_init_one(&src, data, datalen);
+
+ sg_init_table(dst, 2);
+ sg_set_buf(&dst[0], data, datalen);
+ sg_set_buf(&dst[1], skb_put(skb, authlen), authlen);
+
+ aead_request_set_callback(req, 0, NULL, NULL);
+ aead_request_set_assoc(req, assoc, assoclen);
+ aead_request_set_crypt(req, &src, dst, datalen, iv);
+
+ rc = crypto_aead_encrypt(req);
+
+ kfree(req);
+
+ return rc;
+}
+
+static int llsec_do_encrypt(struct sk_buff *skb,
+ const struct mac802154_llsec *sec,
+ const struct ieee802154_hdr *hdr,
+ struct mac802154_llsec_key *key)
+{
+ if (hdr->sec.level == IEEE802154_SCF_SECLEVEL_ENC)
+ return llsec_do_encrypt_unauth(skb, sec, hdr, key);
+ else
+ return llsec_do_encrypt_auth(skb, sec, hdr, key);
+}
+
+int mac802154_llsec_encrypt(struct mac802154_llsec *sec, struct sk_buff *skb)
+{
+ struct ieee802154_hdr hdr;
+ int rc, authlen, hlen;
+ struct mac802154_llsec_key *key;
+ u32 frame_ctr;
+
+ hlen = ieee802154_hdr_pull(skb, &hdr);
+
+ if (hlen < 0 || hdr.fc.type != IEEE802154_FC_TYPE_DATA)
+ return -EINVAL;
+
+ if (!hdr.fc.security_enabled || hdr.sec.level == 0) {
+ skb_push(skb, hlen);
+ return 0;
+ }
+
+ authlen = ieee802154_sechdr_authtag_len(&hdr.sec);
+
+ if (skb->len + hlen + authlen + IEEE802154_MFR_SIZE > IEEE802154_MTU)
+ return -EMSGSIZE;
+
+ rcu_read_lock();
+
+ read_lock_bh(&sec->lock);
+
+ if (!sec->params.enabled) {
+ rc = -EINVAL;
+ goto fail_read;
+ }
+
+ key = llsec_lookup_key(sec, &hdr, &hdr.dest, NULL);
+ if (!key) {
+ rc = -ENOKEY;
+ goto fail_read;
+ }
+
+ read_unlock_bh(&sec->lock);
+
+ write_lock_bh(&sec->lock);
+
+ frame_ctr = be32_to_cpu(sec->params.frame_counter);
+ hdr.sec.frame_counter = cpu_to_le32(frame_ctr);
+ if (frame_ctr == 0xFFFFFFFF) {
+ write_unlock_bh(&sec->lock);
+ llsec_key_put(key);
+ rc = -EOVERFLOW;
+ goto fail;
+ }
+
+ sec->params.frame_counter = cpu_to_be32(frame_ctr + 1);
+
+ write_unlock_bh(&sec->lock);
+
+ rcu_read_unlock();
+
+ skb->mac_len = ieee802154_hdr_push(skb, &hdr);
+ skb_reset_mac_header(skb);
+
+ rc = llsec_do_encrypt(skb, sec, &hdr, key);
+ llsec_key_put(key);
+
+ return rc < 0 ? rc : 0;
+
+fail_read:
+ read_unlock(&sec->lock);
+fail:
+ rcu_read_unlock();
+ return rc;
+}
projects / cascardo / linux.git / commitdiff