ieee80211_rx_result ieee80211_crypto_aes_cmac_decrypt(struct ieee80211_rx_data *rx) { struct sk_buff *skb = rx->skb; struct ieee80211_key *key = rx->key; struct ieee80211_mmie *mmie; u8 aad[20], mic[8], ipn[6]; struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; if (!ieee80211_is_mgmt(hdr->frame_control)) return RX_CONTINUE; if ((rx->status->flag & RX_FLAG_DECRYPTED) && (rx->status->flag & RX_FLAG_IV_STRIPPED)) return RX_CONTINUE; if (skb->len < 24 + sizeof(*mmie)) return RX_DROP_UNUSABLE; mmie = (struct ieee80211_mmie *) (skb->data + skb->len - sizeof(*mmie)); if (mmie->element_id != WLAN_EID_MMIE || mmie->length != sizeof(*mmie) - 2) return RX_DROP_UNUSABLE; /* Invalid MMIE */ bip_ipn_swap(ipn, mmie->sequence_number); if (memcmp(ipn, key->u.aes_cmac.rx_pn, 6) <= 0) { key->u.aes_cmac.replays++; return RX_DROP_UNUSABLE; } if (!(rx->status->flag & RX_FLAG_DECRYPTED)) { /* hardware didn't decrypt/verify MIC */ bip_aad(skb, aad); ieee80211_aes_cmac(key->u.aes_cmac.tfm, key->u.aes_cmac.rx_crypto_buf, aad, skb->data + 24, skb->len - 24, mic); if (memcmp(mic, mmie->mic, sizeof(mmie->mic)) != 0) { key->u.aes_cmac.icverrors++; return RX_DROP_UNUSABLE; } } memcpy(key->u.aes_cmac.rx_pn, ipn, 6); /* Remove MMIE */ skb_trim(skb, skb->len - sizeof(*mmie)); return RX_CONTINUE; }
ieee80211_tx_result ieee80211_crypto_aes_cmac_encrypt(struct ieee80211_tx_data *tx) { struct sk_buff *skb = tx->skb; struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); struct ieee80211_key *key = tx->key; struct ieee80211_mmie *mmie; u8 *pn, aad[20]; int i; if (tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) { /* hwaccel */ info->control.hw_key = &tx->key->conf; return 0; } if (WARN_ON(skb_tailroom(skb) < sizeof(*mmie))) return TX_DROP; mmie = (struct ieee80211_mmie *) skb_put(skb, sizeof(*mmie)); mmie->element_id = WLAN_EID_MMIE; mmie->length = sizeof(*mmie) - 2; mmie->key_id = cpu_to_le16(key->conf.keyidx); /* PN = PN + 1 */ pn = key->u.aes_cmac.tx_pn; for (i = sizeof(key->u.aes_cmac.tx_pn) - 1; i >= 0; i--) { pn[i]++; if (pn[i]) break; } bip_ipn_swap(mmie->sequence_number, pn); bip_aad(skb, aad); /* * MIC = AES-128-CMAC(IGTK, AAD || Management Frame Body || MMIE, 64) */ ieee80211_aes_cmac(key->u.aes_cmac.tfm, key->u.aes_cmac.tx_crypto_buf, aad, skb->data + 24, skb->len - 24, mmie->mic); return TX_CONTINUE; }
ieee80211_tx_result ieee80211_crypto_aes_cmac_encrypt(struct ieee80211_tx_data *tx) { struct sk_buff *skb = tx->skb; struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); struct ieee80211_key *key = tx->key; struct ieee80211_mmie *mmie; u8 aad[20]; u64 pn64; if (info->control.hw_key) return 0; if (WARN_ON(skb_tailroom(skb) < sizeof(*mmie))) return TX_DROP; mmie = (struct ieee80211_mmie *) skb_put(skb, sizeof(*mmie)); mmie->element_id = WLAN_EID_MMIE; mmie->length = sizeof(*mmie) - 2; mmie->key_id = cpu_to_le16(key->conf.keyidx); /* PN = PN + 1 */ pn64 = atomic64_inc_return(&key->u.aes_cmac.tx_pn); bip_ipn_set64(mmie->sequence_number, pn64); bip_aad(skb, aad); /* * MIC = AES-128-CMAC(IGTK, AAD || Management Frame Body || MMIE, 64) */ ieee80211_aes_cmac(key->u.aes_cmac.tfm, aad, skb->data + 24, skb->len - 24, mmie->mic); return TX_CONTINUE; }