diff options
Diffstat (limited to 'net/mac80211/wpa.c')
-rw-r--r-- | net/mac80211/wpa.c | 224 |
1 files changed, 224 insertions, 0 deletions
diff --git a/net/mac80211/wpa.c b/net/mac80211/wpa.c index 12398fde02e8..96b65c240109 100644 --- a/net/mac80211/wpa.c +++ b/net/mac80211/wpa.c @@ -22,6 +22,7 @@ #include "tkip.h" #include "aes_ccm.h" #include "aes_cmac.h" +#include "aes_gcm.h" #include "wpa.h" ieee80211_tx_result @@ -546,6 +547,229 @@ ieee80211_crypto_ccmp_decrypt(struct ieee80211_rx_data *rx) return RX_CONTINUE; } +static void gcmp_special_blocks(struct sk_buff *skb, u8 *pn, u8 *j_0, u8 *aad) +{ + __le16 mask_fc; + u8 qos_tid; + struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data; + + memcpy(j_0, hdr->addr2, ETH_ALEN); + memcpy(&j_0[ETH_ALEN], pn, IEEE80211_GCMP_PN_LEN); + j_0[13] = 0; + j_0[14] = 0; + j_0[AES_BLOCK_SIZE - 1] = 0x01; + + /* AAD (extra authenticate-only data) / masked 802.11 header + * FC | A1 | A2 | A3 | SC | [A4] | [QC] + */ + put_unaligned_be16(ieee80211_hdrlen(hdr->frame_control) - 2, &aad[0]); + /* Mask FC: zero subtype b4 b5 b6 (if not mgmt) + * Retry, PwrMgt, MoreData; set Protected + */ + mask_fc = hdr->frame_control; + mask_fc &= ~cpu_to_le16(IEEE80211_FCTL_RETRY | + IEEE80211_FCTL_PM | IEEE80211_FCTL_MOREDATA); + if (!ieee80211_is_mgmt(hdr->frame_control)) + mask_fc &= ~cpu_to_le16(0x0070); + mask_fc |= cpu_to_le16(IEEE80211_FCTL_PROTECTED); + + put_unaligned(mask_fc, (__le16 *)&aad[2]); + memcpy(&aad[4], &hdr->addr1, 3 * ETH_ALEN); + + /* Mask Seq#, leave Frag# */ + aad[22] = *((u8 *)&hdr->seq_ctrl) & 0x0f; + aad[23] = 0; + + if (ieee80211_is_data_qos(hdr->frame_control)) + qos_tid = *ieee80211_get_qos_ctl(hdr) & + IEEE80211_QOS_CTL_TID_MASK; + else + qos_tid = 0; + + if (ieee80211_has_a4(hdr->frame_control)) { + memcpy(&aad[24], hdr->addr4, ETH_ALEN); + aad[30] = qos_tid; + aad[31] = 0; + } else { + memset(&aad[24], 0, ETH_ALEN + IEEE80211_QOS_CTL_LEN); + aad[24] = qos_tid; + } +} + +static inline void gcmp_pn2hdr(u8 *hdr, const u8 *pn, int key_id) +{ + hdr[0] = pn[5]; + hdr[1] = pn[4]; + hdr[2] = 0; + hdr[3] = 0x20 | (key_id << 6); + hdr[4] = pn[3]; + hdr[5] = pn[2]; + hdr[6] = pn[1]; + hdr[7] = pn[0]; +} + +static inline void gcmp_hdr2pn(u8 *pn, const u8 *hdr) +{ + pn[0] = hdr[7]; + pn[1] = hdr[6]; + pn[2] = hdr[5]; + pn[3] = hdr[4]; + pn[4] = hdr[1]; + pn[5] = hdr[0]; +} + +static int gcmp_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb) +{ + struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data; + struct ieee80211_key *key = tx->key; + struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); + int hdrlen, len, tail; + u8 *pos; + u8 pn[6]; + u64 pn64; + u8 aad[2 * AES_BLOCK_SIZE]; + u8 j_0[AES_BLOCK_SIZE]; + + if (info->control.hw_key && + !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_IV) && + !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE) && + !((info->control.hw_key->flags & + IEEE80211_KEY_FLAG_GENERATE_IV_MGMT) && + ieee80211_is_mgmt(hdr->frame_control))) { + /* hwaccel has no need for preallocated room for GCMP + * header or MIC fields + */ + return 0; + } + + hdrlen = ieee80211_hdrlen(hdr->frame_control); + len = skb->len - hdrlen; + + if (info->control.hw_key) + tail = 0; + else + tail = IEEE80211_GCMP_MIC_LEN; + + if (WARN_ON(skb_tailroom(skb) < tail || + skb_headroom(skb) < IEEE80211_GCMP_HDR_LEN)) + return -1; + + pos = skb_push(skb, IEEE80211_GCMP_HDR_LEN); + memmove(pos, pos + IEEE80211_GCMP_HDR_LEN, hdrlen); + skb_set_network_header(skb, skb_network_offset(skb) + + IEEE80211_GCMP_HDR_LEN); + + /* the HW only needs room for the IV, but not the actual IV */ + if (info->control.hw_key && + (info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE)) + return 0; + + hdr = (struct ieee80211_hdr *)pos; + pos += hdrlen; + + pn64 = atomic64_inc_return(&key->u.gcmp.tx_pn); + + pn[5] = pn64; + pn[4] = pn64 >> 8; + pn[3] = pn64 >> 16; + pn[2] = pn64 >> 24; + pn[1] = pn64 >> 32; + pn[0] = pn64 >> 40; + + gcmp_pn2hdr(pos, pn, key->conf.keyidx); + + /* hwaccel - with software GCMP header */ + if (info->control.hw_key) + return 0; + + pos += IEEE80211_GCMP_HDR_LEN; + gcmp_special_blocks(skb, pn, j_0, aad); + ieee80211_aes_gcm_encrypt(key->u.gcmp.tfm, j_0, aad, pos, len, + skb_put(skb, IEEE80211_GCMP_MIC_LEN)); + + return 0; +} + +ieee80211_tx_result +ieee80211_crypto_gcmp_encrypt(struct ieee80211_tx_data *tx) +{ + struct sk_buff *skb; + + ieee80211_tx_set_protected(tx); + + skb_queue_walk(&tx->skbs, skb) { + if (gcmp_encrypt_skb(tx, skb) < 0) + return TX_DROP; + } + + return TX_CONTINUE; +} + +ieee80211_rx_result +ieee80211_crypto_gcmp_decrypt(struct ieee80211_rx_data *rx) +{ + struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data; + int hdrlen; + struct ieee80211_key *key = rx->key; + struct sk_buff *skb = rx->skb; + struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb); + u8 pn[IEEE80211_GCMP_PN_LEN]; + int data_len; + int queue; + + hdrlen = ieee80211_hdrlen(hdr->frame_control); + + if (!ieee80211_is_data(hdr->frame_control) && + !ieee80211_is_robust_mgmt_frame(skb)) + return RX_CONTINUE; + + data_len = skb->len - hdrlen - IEEE80211_GCMP_HDR_LEN - + IEEE80211_GCMP_MIC_LEN; + if (!rx->sta || data_len < 0) + return RX_DROP_UNUSABLE; + + if (status->flag & RX_FLAG_DECRYPTED) { + if (!pskb_may_pull(rx->skb, hdrlen + IEEE80211_GCMP_HDR_LEN)) + return RX_DROP_UNUSABLE; + } else { + if (skb_linearize(rx->skb)) + return RX_DROP_UNUSABLE; + } + + gcmp_hdr2pn(pn, skb->data + hdrlen); + + queue = rx->security_idx; + + if (memcmp(pn, key->u.gcmp.rx_pn[queue], IEEE80211_GCMP_PN_LEN) <= 0) { + key->u.gcmp.replays++; + return RX_DROP_UNUSABLE; + } + + if (!(status->flag & RX_FLAG_DECRYPTED)) { + u8 aad[2 * AES_BLOCK_SIZE]; + u8 j_0[AES_BLOCK_SIZE]; + /* hardware didn't decrypt/verify MIC */ + gcmp_special_blocks(skb, pn, j_0, aad); + + if (ieee80211_aes_gcm_decrypt( + key->u.gcmp.tfm, j_0, aad, + skb->data + hdrlen + IEEE80211_GCMP_HDR_LEN, + data_len, + skb->data + skb->len - IEEE80211_GCMP_MIC_LEN)) + return RX_DROP_UNUSABLE; + } + + memcpy(key->u.gcmp.rx_pn[queue], pn, IEEE80211_GCMP_PN_LEN); + + /* Remove GCMP header and MIC */ + if (pskb_trim(skb, skb->len - IEEE80211_GCMP_MIC_LEN)) + return RX_DROP_UNUSABLE; + memmove(skb->data + IEEE80211_GCMP_HDR_LEN, skb->data, hdrlen); + skb_pull(skb, IEEE80211_GCMP_HDR_LEN); + + return RX_CONTINUE; +} + static ieee80211_tx_result ieee80211_crypto_cs_encrypt(struct ieee80211_tx_data *tx, struct sk_buff *skb) |