diff options
Diffstat (limited to 'net/mac80211/wpa.c')
| -rw-r--r-- | net/mac80211/wpa.c | 276 |
1 files changed, 215 insertions, 61 deletions
diff --git a/net/mac80211/wpa.c b/net/mac80211/wpa.c index b758350919f..9b3dcc20114 100644 --- a/net/mac80211/wpa.c +++ b/net/mac80211/wpa.c @@ -62,10 +62,10 @@ ieee80211_tx_h_michael_mic_add(struct ieee80211_tx_data *tx) tail = MICHAEL_MIC_LEN; if (!info->control.hw_key) - tail += TKIP_ICV_LEN; + tail += IEEE80211_TKIP_ICV_LEN; if (WARN_ON(skb_tailroom(skb) < tail || - skb_headroom(skb) < TKIP_IV_LEN)) + skb_headroom(skb) < IEEE80211_TKIP_IV_LEN)) return TX_DROP; key = &tx->key->conf.key[NL80211_TKIP_DATA_OFFSET_TX_MIC_KEY]; @@ -104,9 +104,10 @@ ieee80211_rx_h_michael_mic_verify(struct ieee80211_rx_data *rx) */ if (status->flag & (RX_FLAG_MMIC_STRIPPED | RX_FLAG_IV_STRIPPED)) { if (status->flag & RX_FLAG_MMIC_ERROR) - goto mic_fail; + goto mic_fail_no_key; - if (!(status->flag & RX_FLAG_IV_STRIPPED) && rx->key) + if (!(status->flag & RX_FLAG_IV_STRIPPED) && rx->key && + rx->key->conf.cipher == WLAN_CIPHER_SUITE_TKIP) goto update_iv; return RX_CONTINUE; @@ -126,7 +127,7 @@ ieee80211_rx_h_michael_mic_verify(struct ieee80211_rx_data *rx) * APs with pairwise keys should never receive Michael MIC * errors for non-zero keyidx because these are reserved for * group keys and only the AP is sending real multicast - * frames in the BSS. ( + * frames in the BSS. */ return RX_DROP_UNUSABLE; } @@ -138,6 +139,10 @@ ieee80211_rx_h_michael_mic_verify(struct ieee80211_rx_data *rx) if (skb->len < hdrlen + MICHAEL_MIC_LEN) return RX_DROP_UNUSABLE; + if (skb_linearize(rx->skb)) + return RX_DROP_UNUSABLE; + hdr = (void *)skb->data; + data = skb->data + hdrlen; data_len = skb->len - hdrlen - MICHAEL_MIC_LEN; key = &rx->key->conf.key[NL80211_TKIP_DATA_OFFSET_RX_MIC_KEY]; @@ -156,6 +161,9 @@ update_iv: return RX_CONTINUE; mic_fail: + rx->key->u.tkip.mic_failures++; + +mic_fail_no_key: /* * In some cases the key can be unset - e.g. a multicast packet, in * a driver that supports HW encryption. Send up the key idx only if @@ -173,13 +181,13 @@ static int tkip_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); - unsigned long flags; unsigned int hdrlen; int len, tail; u8 *pos; if (info->control.hw_key && - !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_IV)) { + !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_IV) && + !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE)) { /* hwaccel - with no need for software-generated IV */ return 0; } @@ -190,30 +198,37 @@ static int tkip_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb) if (info->control.hw_key) tail = 0; else - tail = TKIP_ICV_LEN; + tail = IEEE80211_TKIP_ICV_LEN; if (WARN_ON(skb_tailroom(skb) < tail || - skb_headroom(skb) < TKIP_IV_LEN)) + skb_headroom(skb) < IEEE80211_TKIP_IV_LEN)) return -1; - pos = skb_push(skb, TKIP_IV_LEN); - memmove(pos, pos + TKIP_IV_LEN, hdrlen); + pos = skb_push(skb, IEEE80211_TKIP_IV_LEN); + memmove(pos, pos + IEEE80211_TKIP_IV_LEN, hdrlen); + skb_set_network_header(skb, skb_network_offset(skb) + + IEEE80211_TKIP_IV_LEN); pos += hdrlen; + /* 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; + /* Increase IV for the frame */ - spin_lock_irqsave(&key->u.tkip.txlock, flags); + spin_lock(&key->u.tkip.txlock); key->u.tkip.tx.iv16++; if (key->u.tkip.tx.iv16 == 0) key->u.tkip.tx.iv32++; pos = ieee80211_tkip_add_iv(pos, key); - spin_unlock_irqrestore(&key->u.tkip.txlock, flags); + spin_unlock(&key->u.tkip.txlock); /* hwaccel - with software IV */ if (info->control.hw_key) return 0; /* Add room for ICV */ - skb_put(skb, TKIP_ICV_LEN); + skb_put(skb, IEEE80211_TKIP_ICV_LEN); return ieee80211_tkip_encrypt_data(tx->local->wep_tx_tfm, key, skb, pos, len); @@ -253,6 +268,11 @@ ieee80211_crypto_tkip_decrypt(struct ieee80211_rx_data *rx) if (!rx->sta || skb->len - hdrlen < 12) return RX_DROP_UNUSABLE; + /* it may be possible to optimize this a bit more */ + if (skb_linearize(rx->skb)) + return RX_DROP_UNUSABLE; + hdr = (void *)skb->data; + /* * Let TKIP code verify IV, but skip decryption. * In the case where hardware checks the IV as well, @@ -271,32 +291,25 @@ ieee80211_crypto_tkip_decrypt(struct ieee80211_rx_data *rx) return RX_DROP_UNUSABLE; /* Trim ICV */ - skb_trim(skb, skb->len - TKIP_ICV_LEN); + skb_trim(skb, skb->len - IEEE80211_TKIP_ICV_LEN); /* Remove IV */ - memmove(skb->data + TKIP_IV_LEN, skb->data, hdrlen); - skb_pull(skb, TKIP_IV_LEN); + memmove(skb->data + IEEE80211_TKIP_IV_LEN, skb->data, hdrlen); + skb_pull(skb, IEEE80211_TKIP_IV_LEN); return RX_CONTINUE; } -static void ccmp_special_blocks(struct sk_buff *skb, u8 *pn, u8 *scratch, - int encrypted) +static void ccmp_special_blocks(struct sk_buff *skb, u8 *pn, u8 *b_0, u8 *aad) { __le16 mask_fc; int a4_included, mgmt; u8 qos_tid; - u8 *b_0, *aad; - u16 data_len, len_a; + u16 len_a; unsigned int hdrlen; struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data; - memset(scratch, 0, 6 * AES_BLOCK_SIZE); - - b_0 = scratch + 3 * AES_BLOCK_SIZE; - aad = scratch + 4 * AES_BLOCK_SIZE; - /* * Mask FC: zero subtype b4 b5 b6 (if not mgmt) * Retry, PwrMgt, MoreData; set Protected @@ -318,20 +331,21 @@ static void ccmp_special_blocks(struct sk_buff *skb, u8 *pn, u8 *scratch, else qos_tid = 0; - data_len = skb->len - hdrlen - CCMP_HDR_LEN; - if (encrypted) - data_len -= CCMP_MIC_LEN; + /* In CCM, the initial vectors (IV) used for CTR mode encryption and CBC + * mode authentication are not allowed to collide, yet both are derived + * from this vector b_0. We only set L := 1 here to indicate that the + * data size can be represented in (L+1) bytes. The CCM layer will take + * care of storing the data length in the top (L+1) bytes and setting + * and clearing the other bits as is required to derive the two IVs. + */ + b_0[0] = 0x1; - /* First block, b_0 */ - b_0[0] = 0x59; /* flags: Adata: 1, M: 011, L: 001 */ /* Nonce: Nonce Flags | A2 | PN * Nonce Flags: Priority (b0..b3) | Management (b4) | Reserved (b5..b7) */ b_0[1] = qos_tid | (mgmt << 4); memcpy(&b_0[2], hdr->addr2, ETH_ALEN); - memcpy(&b_0[8], pn, CCMP_PN_LEN); - /* l(m) */ - put_unaligned_be16(data_len, &b_0[14]); + memcpy(&b_0[8], pn, IEEE80211_CCMP_PN_LEN); /* AAD (extra authenticate-only data) / masked 802.11 header * FC | A1 | A2 | A3 | SC | [A4] | [QC] */ @@ -387,11 +401,15 @@ static int ccmp_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb) u8 *pos; u8 pn[6]; u64 pn64; - u8 scratch[6 * AES_BLOCK_SIZE]; + u8 aad[2 * AES_BLOCK_SIZE]; + u8 b_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_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 CCMP * header or MIC fields @@ -405,14 +423,16 @@ static int ccmp_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb) if (info->control.hw_key) tail = 0; else - tail = CCMP_MIC_LEN; + tail = IEEE80211_CCMP_MIC_LEN; if (WARN_ON(skb_tailroom(skb) < tail || - skb_headroom(skb) < CCMP_HDR_LEN)) + skb_headroom(skb) < IEEE80211_CCMP_HDR_LEN)) return -1; - pos = skb_push(skb, CCMP_HDR_LEN); - memmove(pos, pos + CCMP_HDR_LEN, hdrlen); + pos = skb_push(skb, IEEE80211_CCMP_HDR_LEN); + memmove(pos, pos + IEEE80211_CCMP_HDR_LEN, hdrlen); + skb_set_network_header(skb, skb_network_offset(skb) + + IEEE80211_CCMP_HDR_LEN); /* the HW only needs room for the IV, but not the actual IV */ if (info->control.hw_key && @@ -437,10 +457,10 @@ static int ccmp_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb) if (info->control.hw_key) return 0; - pos += CCMP_HDR_LEN; - ccmp_special_blocks(skb, pn, scratch, 0); - ieee80211_aes_ccm_encrypt(key->u.ccmp.tfm, scratch, pos, len, - pos, skb_put(skb, CCMP_MIC_LEN)); + pos += IEEE80211_CCMP_HDR_LEN; + ccmp_special_blocks(skb, pn, b_0, aad); + ieee80211_aes_ccm_encrypt(key->u.ccmp.tfm, b_0, aad, pos, len, + skb_put(skb, IEEE80211_CCMP_MIC_LEN)); return 0; } @@ -470,63 +490,179 @@ ieee80211_crypto_ccmp_decrypt(struct ieee80211_rx_data *rx) struct ieee80211_key *key = rx->key; struct sk_buff *skb = rx->skb; struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb); - u8 pn[CCMP_PN_LEN]; + u8 pn[IEEE80211_CCMP_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(hdr)) + !ieee80211_is_robust_mgmt_frame(skb)) return RX_CONTINUE; - data_len = skb->len - hdrlen - CCMP_HDR_LEN - CCMP_MIC_LEN; + data_len = skb->len - hdrlen - IEEE80211_CCMP_HDR_LEN - + IEEE80211_CCMP_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_CCMP_HDR_LEN)) + return RX_DROP_UNUSABLE; + } else { + if (skb_linearize(rx->skb)) + return RX_DROP_UNUSABLE; + } + ccmp_hdr2pn(pn, skb->data + hdrlen); queue = rx->security_idx; - if (memcmp(pn, key->u.ccmp.rx_pn[queue], CCMP_PN_LEN) <= 0) { + if (memcmp(pn, key->u.ccmp.rx_pn[queue], IEEE80211_CCMP_PN_LEN) <= 0) { key->u.ccmp.replays++; return RX_DROP_UNUSABLE; } if (!(status->flag & RX_FLAG_DECRYPTED)) { - u8 scratch[6 * AES_BLOCK_SIZE]; + u8 aad[2 * AES_BLOCK_SIZE]; + u8 b_0[AES_BLOCK_SIZE]; /* hardware didn't decrypt/verify MIC */ - ccmp_special_blocks(skb, pn, scratch, 1); + ccmp_special_blocks(skb, pn, b_0, aad); if (ieee80211_aes_ccm_decrypt( - key->u.ccmp.tfm, scratch, - skb->data + hdrlen + CCMP_HDR_LEN, data_len, - skb->data + skb->len - CCMP_MIC_LEN, - skb->data + hdrlen + CCMP_HDR_LEN)) + key->u.ccmp.tfm, b_0, aad, + skb->data + hdrlen + IEEE80211_CCMP_HDR_LEN, + data_len, + skb->data + skb->len - IEEE80211_CCMP_MIC_LEN)) return RX_DROP_UNUSABLE; } - memcpy(key->u.ccmp.rx_pn[queue], pn, CCMP_PN_LEN); + memcpy(key->u.ccmp.rx_pn[queue], pn, IEEE80211_CCMP_PN_LEN); /* Remove CCMP header and MIC */ - skb_trim(skb, skb->len - CCMP_MIC_LEN); - memmove(skb->data + CCMP_HDR_LEN, skb->data, hdrlen); - skb_pull(skb, CCMP_HDR_LEN); + if (pskb_trim(skb, skb->len - IEEE80211_CCMP_MIC_LEN)) + return RX_DROP_UNUSABLE; + memmove(skb->data + IEEE80211_CCMP_HDR_LEN, skb->data, hdrlen); + skb_pull(skb, IEEE80211_CCMP_HDR_LEN); return RX_CONTINUE; } +static ieee80211_tx_result +ieee80211_crypto_cs_encrypt(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); + const struct ieee80211_cipher_scheme *cs = key->sta->cipher_scheme; + int hdrlen; + u8 *pos; + + if (info->control.hw_key && + !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE)) { + /* hwaccel has no need for preallocated head room */ + return TX_CONTINUE; + } + + if (unlikely(skb_headroom(skb) < cs->hdr_len && + pskb_expand_head(skb, cs->hdr_len, 0, GFP_ATOMIC))) + return TX_DROP; + + hdrlen = ieee80211_hdrlen(hdr->frame_control); + + pos = skb_push(skb, cs->hdr_len); + memmove(pos, pos + cs->hdr_len, hdrlen); + skb_set_network_header(skb, skb_network_offset(skb) + cs->hdr_len); + + return TX_CONTINUE; +} + +static inline int ieee80211_crypto_cs_pn_compare(u8 *pn1, u8 *pn2, int len) +{ + int i; + + /* pn is little endian */ + for (i = len - 1; i >= 0; i--) { + if (pn1[i] < pn2[i]) + return -1; + else if (pn1[i] > pn2[i]) + return 1; + } + + return 0; +} + +static ieee80211_rx_result +ieee80211_crypto_cs_decrypt(struct ieee80211_rx_data *rx) +{ + struct ieee80211_key *key = rx->key; + struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data; + const struct ieee80211_cipher_scheme *cs = NULL; + int hdrlen = ieee80211_hdrlen(hdr->frame_control); + struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb); + int data_len; + u8 *rx_pn; + u8 *skb_pn; + u8 qos_tid; + + if (!rx->sta || !rx->sta->cipher_scheme || + !(status->flag & RX_FLAG_DECRYPTED)) + return RX_DROP_UNUSABLE; + + if (!ieee80211_is_data(hdr->frame_control)) + return RX_CONTINUE; + + cs = rx->sta->cipher_scheme; + + data_len = rx->skb->len - hdrlen - cs->hdr_len; + + if (data_len < 0) + return RX_DROP_UNUSABLE; + + 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 (skb_linearize(rx->skb)) + return RX_DROP_UNUSABLE; + + hdr = (struct ieee80211_hdr *)rx->skb->data; + + rx_pn = key->u.gen.rx_pn[qos_tid]; + skb_pn = rx->skb->data + hdrlen + cs->pn_off; + + if (ieee80211_crypto_cs_pn_compare(skb_pn, rx_pn, cs->pn_len) <= 0) + return RX_DROP_UNUSABLE; + + memcpy(rx_pn, skb_pn, cs->pn_len); + + /* remove security header and MIC */ + if (pskb_trim(rx->skb, rx->skb->len - cs->mic_len)) + return RX_DROP_UNUSABLE; + + memmove(rx->skb->data + cs->hdr_len, rx->skb->data, hdrlen); + skb_pull(rx->skb, cs->hdr_len); + + return RX_CONTINUE; +} static void bip_aad(struct sk_buff *skb, u8 *aad) { + __le16 mask_fc; + struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; + /* BIP AAD: FC(masked) || A1 || A2 || A3 */ /* FC type/subtype */ - aad[0] = skb->data[0]; /* Mask FC Retry, PwrMgt, MoreData flags to zero */ - aad[1] = skb->data[1] & ~(BIT(4) | BIT(5) | BIT(6)); + mask_fc = hdr->frame_control; + mask_fc &= ~cpu_to_le16(IEEE80211_FCTL_RETRY | IEEE80211_FCTL_PM | + IEEE80211_FCTL_MOREDATA); + put_unaligned(mask_fc, (__le16 *) &aad[0]); /* A1 || A2 || A3 */ - memcpy(aad + 2, skb->data + 4, 3 * ETH_ALEN); + memcpy(aad + 2, &hdr->addr1, 3 * ETH_ALEN); } @@ -609,6 +745,8 @@ ieee80211_crypto_aes_cmac_decrypt(struct ieee80211_rx_data *rx) if (!ieee80211_is_mgmt(hdr->frame_control)) return RX_CONTINUE; + /* management frames are already linear */ + if (skb->len < 24 + sizeof(*mmie)) return RX_DROP_UNUSABLE; @@ -649,6 +787,7 @@ ieee80211_crypto_hw_encrypt(struct ieee80211_tx_data *tx) { struct sk_buff *skb; struct ieee80211_tx_info *info = NULL; + ieee80211_tx_result res; skb_queue_walk(&tx->skbs, skb) { info = IEEE80211_SKB_CB(skb); @@ -656,9 +795,24 @@ ieee80211_crypto_hw_encrypt(struct ieee80211_tx_data *tx) /* handle hw-only algorithm */ if (!info->control.hw_key) return TX_DROP; + + if (tx->key->sta->cipher_scheme) { + res = ieee80211_crypto_cs_encrypt(tx, skb); + if (res != TX_CONTINUE) + return res; + } } ieee80211_tx_set_protected(tx); return TX_CONTINUE; } + +ieee80211_rx_result +ieee80211_crypto_hw_decrypt(struct ieee80211_rx_data *rx) +{ + if (rx->sta->cipher_scheme) + return ieee80211_crypto_cs_decrypt(rx); + + return RX_DROP_UNUSABLE; +} |
