/* * Copyright (C) 2014 Fraunhofer ITWM * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 * as published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * Written by: * Phoebe Buckheister <phoebe.buckheister@itwm.fraunhofer.de> */ #include <linux/err.h> #include <linux/bug.h> #include <linux/completion.h> #include <linux/ieee802154.h> #include <crypto/aead.h> #include <crypto/skcipher.h> #include "ieee802154_i.h" #include "llsec.h" static void llsec_key_put(struct mac802154_llsec_key *key); static bool llsec_key_id_equal(const struct ieee802154_llsec_key_id *a, const struct ieee802154_llsec_key_id *b); static void llsec_dev_free(struct mac802154_llsec_device *dev); void mac802154_llsec_init(struct mac802154_llsec *sec) { memset(sec, 0, sizeof(*sec)); memset(&sec->params.default_key_source, 0xFF, IEEE802154_ADDR_LEN); INIT_LIST_HEAD(&sec->table.security_levels); INIT_LIST_HEAD(&sec->table.devices); INIT_LIST_HEAD(&sec->table.keys); hash_init(sec->devices_short); hash_init(sec->devices_hw); rwlock_init(&sec->lock); } void mac802154_llsec_destroy(struct mac802154_llsec *sec) { struct ieee802154_llsec_seclevel *sl, *sn; struct ieee802154_llsec_device *dev, *dn; struct ieee802154_llsec_key_entry *key, *kn; list_for_each_entry_safe(sl, sn, &sec->table.security_levels, list) { struct mac802154_llsec_seclevel *msl; msl = container_of(sl, struct mac802154_llsec_seclevel, level); list_del(&sl->list); kzfree(msl); } list_for_each_entry_safe(dev, dn, &sec->table.devices, list) { struct mac802154_llsec_device *mdev; mdev = container_of(dev, struct mac802154_llsec_device, dev); list_del(&dev->list); llsec_dev_free(mdev); } list_for_each_entry_safe(key, kn, &sec->table.keys, list) { struct mac802154_llsec_key *mkey; mkey = container_of(key->key, struct mac802154_llsec_key, key); list_del(&key->list); llsec_key_put(mkey); kzfree(key); } } int mac802154_llsec_get_params(struct mac802154_llsec *sec, struct ieee802154_llsec_params *params) { read_lock_bh(&sec->lock); *params = sec->params; read_unlock_bh(&sec->lock); return 0; } int mac802154_llsec_set_params(struct mac802154_llsec *sec, const struct ieee802154_llsec_params *params, int changed) { write_lock_bh(&sec->lock); if (changed & IEEE802154_LLSEC_PARAM_ENABLED) sec->params.enabled = params->enabled; if (changed & IEEE802154_LLSEC_PARAM_FRAME_COUNTER) sec->params.frame_counter = params->frame_counter; if (changed & IEEE802154_LLSEC_PARAM_OUT_LEVEL) sec->params.out_level = params->out_level; if (changed & IEEE802154_LLSEC_PARAM_OUT_KEY) sec->params.out_key = params->out_key; if (changed & IEEE802154_LLSEC_PARAM_KEY_SOURCE) sec->params.default_key_source = params->default_key_source; if (changed & IEEE802154_LLSEC_PARAM_PAN_ID) sec->params.pan_id = params->pan_id; if (changed & IEEE802154_LLSEC_PARAM_HWADDR) sec->params.hwaddr = params->hwaddr; if (changed & IEEE802154_LLSEC_PARAM_COORD_HWADDR) sec->params.coord_hwaddr = params->coord_hwaddr; if (changed & IEEE802154_LLSEC_PARAM_COORD_SHORTADDR) sec->params.coord_shortaddr = params->coord_shortaddr; write_unlock_bh(&sec->lock); return 0; } static struct mac802154_llsec_key* llsec_key_alloc(const struct ieee802154_llsec_key *template) { const int authsizes[3] = { 4, 8, 16 }; struct mac802154_llsec_key *key; int i; key = kzalloc(sizeof(*key), GFP_KERNEL); if (!key) return NULL; kref_init(&key->ref); key->key = *template; BUILD_BUG_ON(ARRAY_SIZE(authsizes) != ARRAY_SIZE(key->tfm)); for (i = 0; i < ARRAY_SIZE(key->tfm); i++) { key->tfm[i] = crypto_alloc_aead("ccm(aes)", 0, CRYPTO_ALG_ASYNC); if (IS_ERR(key->tfm[i])) goto err_tfm; if (crypto_aead_setkey(key->tfm[i], template->key, IEEE802154_LLSEC_KEY_SIZE)) goto err_tfm; if (crypto_aead_setauthsize(key->tfm[i], authsizes[i])) goto err_tfm; } key->tfm0 = crypto_alloc_skcipher("ctr(aes)", 0, CRYPTO_ALG_ASYNC); if (IS_ERR(key->tfm0)) goto err_tfm; if (crypto_skcipher_setkey(key->tfm0, template->key, IEEE802154_LLSEC_KEY_SIZE)) goto err_tfm0; return key; err_tfm0: crypto_free_skcipher(key->tfm0); err_tfm: for (i = 0; i < ARRAY_SIZE(key->tfm); i++) if (key->tfm[i]) crypto_free_aead(key->tfm[i]); kzfree(key); return NULL; } static void llsec_key_release(struct kref *ref) { struct mac802154_llsec_key *key; int i; key = container_of(ref, struct mac802154_llsec_key, ref); for (i = 0; i < ARRAY_SIZE(key->tfm); i++) crypto_free_aead(key->tfm[i]); crypto_free_skcipher(key->tfm0); kzfree(key); } static struct mac802154_llsec_key* llsec_key_get(struct mac802154_llsec_key *key) { kref_get(&key->ref); return key; } static void llsec_key_put(struct mac802154_llsec_key *key) { kref_put(&key->ref, llsec_key_release); } static bool llsec_key_id_equal(const struct ieee802154_llsec_key_id *a, const struct ieee802154_llsec_key_id *b) { if (a->mode != b->mode) return false; if (a->mode == IEEE802154_SCF_KEY_IMPLICIT) return ieee802154_addr_equal(&a->device_addr, &b->device_addr); if (a->id != b->id) return false; switch (a->mode) { case IEEE802154_SCF_KEY_INDEX: return true; case IEEE802154_SCF_KEY_SHORT_INDEX: return a->short_source == b->short_source; case IEEE802154_SCF_KEY_HW_INDEX: return a->extended_source == b->extended_source; } return false; } int mac802154_llsec_key_add(struct mac802154_llsec *sec, const struct ieee802154_llsec_key_id *id, const struct ieee802154_llsec_key *key) { struct mac802154_llsec_key *mkey = NULL; struct ieee802154_llsec_key_entry *pos, *new; if (!(key->frame_types & (1 << IEEE802154_FC_TYPE_MAC_CMD)) && key->cmd_frame_ids) return -EINVAL; list_for_each_entry(pos, &sec->table.keys, list) { if (llsec_key_id_equal(&pos->id, id)) return -EEXIST; if (memcmp(pos->key->key, key->key, IEEE802154_LLSEC_KEY_SIZE)) continue; mkey = container_of(pos->key, struct mac802154_llsec_key, key); /* Don't allow multiple instances of the same AES key to have * different allowed frame types/command frame ids, as this is * not possible in the 802.15.4 PIB. */ if (pos->key->frame_types != key->frame_types || pos->key->cmd_frame_ids != key->cmd_frame_ids) return -EEXIST; break; } new = kzalloc(sizeof(*new), GFP_KERNEL); if (!new) return -ENOMEM; if (!mkey) mkey = llsec_key_alloc(key); else mkey = llsec_key_get(mkey); if (!mkey) goto fail; new->id = *id; new->key = &mkey->key; list_add_rcu(&new->list, &sec->table.keys); return 0; fail: kzfree(new); return -ENOMEM; } int mac802154_llsec_key_del(struct mac802154_llsec *sec, const struct ieee802154_llsec_key_id *key) { struct ieee802154_llsec_key_entry *pos; list_for_each_entry(pos, &sec->table.keys, list) { struct mac802154_llsec_key *mkey; mkey = container_of(pos->key, struct mac802154_llsec_key, key); if (llsec_key_id_equal(&pos->id, key)) { list_del_rcu(&pos->list); llsec_key_put(mkey); return 0; } } return -ENOENT; } static bool llsec_dev_use_shortaddr(__le16 short_addr) { return short_addr != cpu_to_le16(IEEE802154_ADDR_UNDEF) && short_addr != cpu_to_le16(0xffff); } static u32 llsec_dev_hash_short(__le16 short_addr, __le16 pan_id) { return ((__force u16)short_addr) << 16 | (__force u16)pan_id; } static u64 llsec_dev_hash_long(__le64 hwaddr) { return (__force u64)hwaddr; } static struct mac802154_llsec_device* llsec_dev_find_short(struct mac802154_llsec *sec, __le16 short_addr, __le16 pan_id) { struct mac802154_llsec_device *dev; u32 key = llsec_dev_hash_short(short_addr, pan_id); hash_for_each_possible_rcu(sec->devices_short, dev, bucket_s, key) { if (dev->dev.short_addr == short_addr && dev->dev.pan_id == pan_id) return dev; } return NULL; } static struct mac802154_llsec_device* llsec_dev_find_long(struct mac802154_llsec *sec, __le64 hwaddr) { struct mac802154_llsec_device *dev; u64 key = llsec_dev_hash_long(hwaddr); hash_for_each_possible_rcu(sec->devices_hw, dev, bucket_hw, key) { if (dev->dev.hwaddr == hwaddr) return dev; } return NULL; } static void llsec_dev_free(struct mac802154_llsec_device *dev) { struct ieee802154_llsec_device_key *pos, *pn; struct mac802154_llsec_device_key *devkey; list_for_each_entry_safe(pos, pn, &dev->dev.keys, list) { devkey = container_of(pos, struct mac802154_llsec_device_key, devkey); list_del(&pos->list); kzfree(devkey); } kzfree(dev); } int mac802154_llsec_dev_add(struct mac802154_llsec *sec, const struct ieee802154_llsec_device *dev) { struct mac802154_llsec_device *entry; u32 skey = llsec_dev_hash_short(dev->short_addr, dev->pan_id); u64 hwkey = llsec_dev_hash_long(dev->hwaddr); BUILD_BUG_ON(sizeof(hwkey) != IEEE802154_ADDR_LEN); if ((llsec_dev_use_shortaddr(dev->short_addr) && llsec_dev_find_short(sec, dev->short_addr, dev->pan_id)) || llsec_dev_find_long(sec, dev->hwaddr)) return -EEXIST; entry = kmalloc(sizeof(*entry), GFP_KERNEL); if (!entry) return -ENOMEM; entry->dev = *dev; spin_lock_init(&entry->lock); INIT_LIST_HEAD(&entry->dev.keys); if (llsec_dev_use_shortaddr(dev->short_addr)) hash_add_rcu(sec->devices_short, &entry->bucket_s, skey); else INIT_HLIST_NODE(&entry->bucket_s); hash_add_rcu(sec->devices_hw, &entry->bucket_hw, hwkey); list_add_tail_rcu(&entry->dev.list, &sec->table.devices); return 0; } static void llsec_dev_free_rcu(struct rcu_head *rcu) { llsec_dev_free(container_of(rcu, struct mac802154_llsec_device, rcu)); } int mac802154_llsec_dev_del(struct mac802154_llsec *sec, __le64 device_addr) { struct mac802154_llsec_device *pos; pos = llsec_dev_find_long(sec, device_addr); if (!pos) return -ENOENT; hash_del_rcu(&pos->bucket_s); hash_del_rcu(&pos->bucket_hw); list_del_rcu(&pos->dev.list); call_rcu(&pos->rcu, llsec_dev_free_rcu); return 0; } static struct mac802154_llsec_device_key* llsec_devkey_find(struct mac802154_llsec_device *dev, const struct ieee802154_llsec_key_id *key) { struct ieee802154_llsec_device_key *devkey; list_for_each_entry_rcu(devkey, &dev->dev.keys, list) { if (!llsec_key_id_equal(key, &devkey->key_id)) continue; return container_of(devkey, struct mac802154_llsec_device_key, devkey); } return NULL; } int mac802154_llsec_devkey_add(struct mac802154_llsec *sec, __le64 dev_addr, const struct ieee802154_llsec_device_key *key) { struct mac802154_llsec_device *dev; struct mac802154_llsec_device_key *devkey; dev = llsec_dev_find_long(sec, dev_addr); if (!dev) return -ENOENT; if (llsec_devkey_find(dev, &key->key_id)) return -EEXIST; devkey = kmalloc(sizeof(*devkey), GFP_KERNEL); if (!devkey) return -ENOMEM; devkey->devkey = *key; list_add_tail_rcu(&devkey->devkey.list, &dev->dev.keys); return 0; } int mac802154_llsec_devkey_del(struct mac802154_llsec *sec, __le64 dev_addr, const struct ieee802154_llsec_device_key *key) { struct mac802154_llsec_device *dev; struct mac802154_llsec_device_key *devkey; dev = llsec_dev_find_long(sec, dev_addr); if (!dev) return -ENOENT; devkey = llsec_devkey_find(dev, &key->key_id); if (!devkey) return -ENOENT; list_del_rcu(&devkey->devkey.list); kfree_rcu(devkey, rcu); return 0; } static struct mac802154_llsec_seclevel* llsec_find_seclevel(const struct mac802154_llsec *sec, const struct ieee802154_llsec_seclevel *sl) { struct ieee802154_llsec_seclevel *pos; list_for_each_entry(pos, &sec->table.security_levels, list) { if (pos->frame_type != sl->frame_type || (pos->frame_type == IEEE802154_FC_TYPE_MAC_CMD && pos->cmd_frame_id != sl->cmd_frame_id) || pos->device_override != sl->device_override || pos->sec_levels != sl->sec_levels) continue; return container_of(pos, struct mac802154_llsec_seclevel, level); } return NULL; } int mac802154_llsec_seclevel_add(struct mac802154_llsec *sec, const struct ieee802154_llsec_seclevel *sl) { struct mac802154_llsec_seclevel *entry; if (llsec_find_seclevel(sec, sl)) return -EEXIST; entry = kmalloc(sizeof(*entry), GFP_KERNEL); if (!entry) return -ENOMEM; entry->level = *sl; list_add_tail_rcu(&entry->level.list, &sec->table.security_levels); return 0; } int mac802154_llsec_seclevel_del(struct mac802154_llsec *sec, const struct ieee802154_llsec_seclevel *sl) { struct mac802154_llsec_seclevel *pos; pos = llsec_find_seclevel(sec, sl); if (!pos) return -ENOENT; list_del_rcu(&pos->level.list); kfree_rcu(pos, rcu); 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; SKCIPHER_REQUEST_ON_STACK(req, key->tfm0); int err; llsec_geniv(iv, sec->params.hwaddr, &hdr->sec); sg_init_one(&src, skb->data, skb->len); skcipher_request_set_tfm(req, key->tfm0); skcipher_request_set_callback(req, 0, NULL, NULL); skcipher_request_set_crypt(req, &src, &src, skb->len, iv); err = crypto_skcipher_encrypt(req); skcipher_request_zero(req); return err; } 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 sg; 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; assoclen = skb->mac_len; data = skb_mac_header(skb) + skb->mac_len; datalen = skb_tail_pointer(skb) - data; skb_put(skb, authlen); sg_init_one(&sg, skb_mac_header(skb), assoclen + datalen + authlen); if (!(hdr->sec.level & IEEE802154_SCF_SECLEVEL_ENC)) { assoclen += datalen; datalen = 0; } aead_request_set_callback(req, 0, NULL, NULL); aead_request_set_crypt(req, &sg, &sg, datalen, iv); aead_request_set_ad(req, assoclen); rc = crypto_aead_encrypt(req); kzfree(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; fail_read: read_unlock_bh(&sec->lock); fail: rcu_read_unlock(); return rc; } static struct mac802154_llsec_device* llsec_lookup_dev(struct mac802154_llsec *sec, const struct ieee802154_addr *addr) { struct ieee802154_addr devaddr = *addr; struct mac802154_llsec_device *dev = NULL; if (devaddr.mode == IEEE802154_ADDR_NONE && llsec_recover_addr(sec, &devaddr) < 0) return NULL; if (devaddr.mode == IEEE802154_ADDR_SHORT) { u32 key = llsec_dev_hash_short(devaddr.short_addr, devaddr.pan_id); hash_for_each_possible_rcu(sec->devices_short, dev, bucket_s, key) { if (dev->dev.pan_id == devaddr.pan_id && dev->dev.short_addr == devaddr.short_addr) return dev; } } else { u64 key = llsec_dev_hash_long(devaddr.extended_addr); hash_for_each_possible_rcu(sec->devices_hw, dev, bucket_hw, key) { if (dev->dev.hwaddr == devaddr.extended_addr) return dev; } } return NULL; } static int llsec_lookup_seclevel(const struct mac802154_llsec *sec, u8 frame_type, u8 cmd_frame_id, struct ieee802154_llsec_seclevel *rlevel) { struct ieee802154_llsec_seclevel *level; list_for_each_entry_rcu(level, &sec->table.security_levels, list) { if (level->frame_type == frame_type && (frame_type != IEEE802154_FC_TYPE_MAC_CMD || level->cmd_frame_id == cmd_frame_id)) { *rlevel = *level; return 0; } } return -EINVAL; } static int llsec_do_decrypt_unauth(struct sk_buff *skb, const struct mac802154_llsec *sec, const struct ieee802154_hdr *hdr, struct mac802154_llsec_key *key, __le64 dev_addr) { u8 iv[16]; unsigned char *data; int datalen; struct scatterlist src; SKCIPHER_REQUEST_ON_STACK(req, key->tfm0); int err; llsec_geniv(iv, dev_addr, &hdr->sec); data = skb_mac_header(skb) + skb->mac_len; datalen = skb_tail_pointer(skb) - data; sg_init_one(&src, data, datalen); skcipher_request_set_tfm(req, key->tfm0); skcipher_request_set_callback(req, 0, NULL, NULL); skcipher_request_set_crypt(req, &src, &src, datalen, iv); err = crypto_skcipher_decrypt(req); skcipher_request_zero(req); return err; } static int llsec_do_decrypt_auth(struct sk_buff *skb, const struct mac802154_llsec *sec, const struct ieee802154_hdr *hdr, struct mac802154_llsec_key *key, __le64 dev_addr) { u8 iv[16]; unsigned char *data; int authlen, datalen, assoclen, rc; struct scatterlist sg; struct aead_request *req; authlen = ieee802154_sechdr_authtag_len(&hdr->sec); llsec_geniv(iv, dev_addr, &hdr->sec); req = aead_request_alloc(llsec_tfm_by_len(key, authlen), GFP_ATOMIC); if (!req) return -ENOMEM; assoclen = skb->mac_len; data = skb_mac_header(skb) + skb->mac_len; datalen = skb_tail_pointer(skb) - data; sg_init_one(&sg, skb_mac_header(skb), assoclen + datalen); if (!(hdr->sec.level & IEEE802154_SCF_SECLEVEL_ENC)) { assoclen += datalen - authlen; datalen = authlen; } aead_request_set_callback(req, 0, NULL, NULL); aead_request_set_crypt(req, &sg, &sg, datalen, iv); aead_request_set_ad(req, assoclen); rc = crypto_aead_decrypt(req); kzfree(req); skb_trim(skb, skb->len - authlen); return rc; } static int llsec_do_decrypt(struct sk_buff *skb, const struct mac802154_llsec *sec, const struct ieee802154_hdr *hdr, struct mac802154_llsec_key *key, __le64 dev_addr) { if (hdr->sec.level == IEEE802154_SCF_SECLEVEL_ENC) return llsec_do_decrypt_unauth(skb, sec, hdr, key, dev_addr); else return llsec_do_decrypt_auth(skb, sec, hdr, key, dev_addr); } static int llsec_update_devkey_record(struct mac802154_llsec_device *dev, const struct ieee802154_llsec_key_id *in_key) { struct mac802154_llsec_device_key *devkey; devkey = llsec_devkey_find(dev, in_key); if (!devkey) { struct mac802154_llsec_device_key *next; next = kzalloc(sizeof(*devkey), GFP_ATOMIC); if (!next) return -ENOMEM; next->devkey.key_id = *in_key; spin_lock_bh(&dev->lock); devkey = llsec_devkey_find(dev, in_key); if (!devkey) list_add_rcu(&next->devkey.list, &dev->dev.keys); else kzfree(next); spin_unlock_bh(&dev->lock); } return 0; } static int llsec_update_devkey_info(struct mac802154_llsec_device *dev, const struct ieee802154_llsec_key_id *in_key, u32 frame_counter) { struct mac802154_llsec_device_key *devkey = NULL; if (dev->dev.key_mode == IEEE802154_LLSEC_DEVKEY_RESTRICT) { devkey = llsec_devkey_find(dev, in_key); if (!devkey) return -ENOENT; } if (dev->dev.key_mode == IEEE802154_LLSEC_DEVKEY_RECORD) { int rc = llsec_update_devkey_record(dev, in_key); if (rc < 0) return rc; } spin_lock_bh(&dev->lock); if ((!devkey && frame_counter < dev->dev.frame_counter) || (devkey && frame_counter < devkey->devkey.frame_counter)) { spin_unlock_bh(&dev->lock); return -EINVAL; } if (devkey) devkey->devkey.frame_counter = frame_counter + 1; else dev->dev.frame_counter = frame_counter + 1; spin_unlock_bh(&dev->lock); return 0; } int mac802154_llsec_decrypt(struct mac802154_llsec *sec, struct sk_buff *skb) { struct ieee802154_hdr hdr; struct mac802154_llsec_key *key; struct ieee802154_llsec_key_id key_id; struct mac802154_llsec_device *dev; struct ieee802154_llsec_seclevel seclevel; int err; __le64 dev_addr; u32 frame_ctr; if (ieee802154_hdr_peek(skb, &hdr) < 0) return -EINVAL; if (!hdr.fc.security_enabled) return 0; if (hdr.fc.version == 0) return -EINVAL; read_lock_bh(&sec->lock); if (!sec->params.enabled) { read_unlock_bh(&sec->lock); return -EINVAL; } read_unlock_bh(&sec->lock); rcu_read_lock(); key = llsec_lookup_key(sec, &hdr, &hdr.source, &key_id); if (!key) { err = -ENOKEY; goto fail; } dev = llsec_lookup_dev(sec, &hdr.source); if (!dev) { err = -EINVAL; goto fail_dev; } if (llsec_lookup_seclevel(sec, hdr.fc.type, 0, &seclevel) < 0) { err = -EINVAL; goto fail_dev; } if (!(seclevel.sec_levels & BIT(hdr.sec.level)) && (hdr.sec.level == 0 && seclevel.device_override && !dev->dev.seclevel_exempt)) { err = -EINVAL; goto fail_dev; } frame_ctr = le32_to_cpu(hdr.sec.frame_counter); if (frame_ctr == 0xffffffff) { err = -EOVERFLOW; goto fail_dev; } err = llsec_update_devkey_info(dev, &key_id, frame_ctr); if (err) goto fail_dev; dev_addr = dev->dev.hwaddr; rcu_read_unlock(); err = llsec_do_decrypt(skb, sec, &hdr, key, dev_addr); llsec_key_put(key); return err; fail_dev: llsec_key_put(key); fail: rcu_read_unlock(); return err; }