diff options
Diffstat (limited to 'net/mac802154/llsec.c')
| -rw-r--r-- | net/mac802154/llsec.c | 247 |
1 files changed, 247 insertions, 0 deletions
diff --git a/net/mac802154/llsec.c b/net/mac802154/llsec.c index 2a4b68e2a93..392653b1b5a 100644 --- a/net/mac802154/llsec.c +++ b/net/mac802154/llsec.c @@ -18,6 +18,7 @@ #include <linux/bug.h> #include <linux/completion.h> #include <net/ieee802154.h> +#include <crypto/algapi.h> #include "mac802154.h" #include "llsec.h" @@ -780,3 +781,249 @@ 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; + struct blkcipher_desc req = { + .tfm = key->tfm0, + .info = iv, + .flags = 0, + }; + + 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); + + return crypto_blkcipher_decrypt_iv(&req, &src, &src, datalen); +} + +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 src, assoc[2]; + 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; + + 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 - authlen); + assoclen += datalen - authlen; + data += datalen - authlen; + datalen = authlen; + } + + sg_init_one(&src, data, datalen); + + aead_request_set_callback(req, 0, NULL, NULL); + aead_request_set_assoc(req, assoc, assoclen); + aead_request_set_crypt(req, &src, &src, datalen, iv); + + rc = crypto_aead_decrypt(req); + + kfree(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_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; + } + + 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; +} |