diff options
Diffstat (limited to 'net/mac80211/wpa.c')
| -rw-r--r-- | net/mac80211/wpa.c | 1030 |
1 files changed, 618 insertions, 412 deletions
diff --git a/net/mac80211/wpa.c b/net/mac80211/wpa.c index 6695efba57e..9b3dcc20114 100644 --- a/net/mac80211/wpa.c +++ b/net/mac80211/wpa.c @@ -1,5 +1,6 @@ /* * Copyright 2002-2004, Instant802 Networks, Inc. + * Copyright 2008, Jouni Malinen <j@w1.fi> * * 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 @@ -8,402 +9,361 @@ #include <linux/netdevice.h> #include <linux/types.h> -#include <linux/slab.h> #include <linux/skbuff.h> #include <linux/compiler.h> +#include <linux/ieee80211.h> +#include <linux/gfp.h> +#include <asm/unaligned.h> #include <net/mac80211.h> +#include <crypto/aes.h> #include "ieee80211_i.h" #include "michael.h" #include "tkip.h" #include "aes_ccm.h" +#include "aes_cmac.h" #include "wpa.h" -static int ieee80211_get_hdr_info(const struct sk_buff *skb, u8 **sa, u8 **da, - u8 *qos_tid, u8 **data, size_t *data_len) +ieee80211_tx_result +ieee80211_tx_h_michael_mic_add(struct ieee80211_tx_data *tx) { - struct ieee80211_hdr *hdr; - size_t hdrlen; - u16 fc; - int a4_included; - u8 *pos; - - hdr = (struct ieee80211_hdr *) skb->data; - fc = le16_to_cpu(hdr->frame_control); - - hdrlen = 24; - if ((fc & (IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS)) == - (IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS)) { - hdrlen += ETH_ALEN; - *sa = hdr->addr4; - *da = hdr->addr3; - } else if (fc & IEEE80211_FCTL_FROMDS) { - *sa = hdr->addr3; - *da = hdr->addr1; - } else if (fc & IEEE80211_FCTL_TODS) { - *sa = hdr->addr2; - *da = hdr->addr3; - } else { - *sa = hdr->addr2; - *da = hdr->addr1; - } - - if (fc & 0x80) - hdrlen += 2; - - *data = skb->data + hdrlen; - *data_len = skb->len - hdrlen; - - a4_included = (fc & (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) == - (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS); - if ((fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA && - fc & IEEE80211_STYPE_QOS_DATA) { - pos = (u8 *) &hdr->addr4; - if (a4_included) - pos += 6; - *qos_tid = pos[0] & 0x0f; - *qos_tid |= 0x80; /* qos_included flag */ - } else - *qos_tid = 0; - - return skb->len < hdrlen ? -1 : 0; -} - - -ieee80211_txrx_result -ieee80211_tx_h_michael_mic_add(struct ieee80211_txrx_data *tx) -{ - u8 *data, *sa, *da, *key, *mic, qos_tid; + u8 *data, *key, *mic; size_t data_len; - u16 fc; + unsigned int hdrlen; + struct ieee80211_hdr *hdr; struct sk_buff *skb = tx->skb; - int authenticator; - int wpa_test = 0; + struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); + int tail; - fc = tx->fc; + hdr = (struct ieee80211_hdr *)skb->data; + if (!tx->key || tx->key->conf.cipher != WLAN_CIPHER_SUITE_TKIP || + skb->len < 24 || !ieee80211_is_data_present(hdr->frame_control)) + return TX_CONTINUE; - if (!tx->key || tx->key->conf.alg != ALG_TKIP || skb->len < 24 || - !WLAN_FC_DATA_PRESENT(fc)) - return TXRX_CONTINUE; + hdrlen = ieee80211_hdrlen(hdr->frame_control); + if (skb->len < hdrlen) + return TX_DROP; - if (ieee80211_get_hdr_info(skb, &sa, &da, &qos_tid, &data, &data_len)) - return TXRX_DROP; + data = skb->data + hdrlen; + data_len = skb->len - hdrlen; - if ((tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) && - !(tx->flags & IEEE80211_TXRXD_FRAGMENTED) && - !(tx->key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC) && - !wpa_test) { - /* hwaccel - with no need for preallocated room for Michael MIC - */ - return TXRX_CONTINUE; + if (unlikely(info->flags & IEEE80211_TX_INTFL_TKIP_MIC_FAILURE)) { + /* Need to use software crypto for the test */ + info->control.hw_key = NULL; } - if (skb_tailroom(skb) < MICHAEL_MIC_LEN) { - I802_DEBUG_INC(tx->local->tx_expand_skb_head); - if (unlikely(pskb_expand_head(skb, TKIP_IV_LEN, - MICHAEL_MIC_LEN + TKIP_ICV_LEN, - GFP_ATOMIC))) { - printk(KERN_DEBUG "%s: failed to allocate more memory " - "for Michael MIC\n", tx->dev->name); - return TXRX_DROP; - } + if (info->control.hw_key && + (info->flags & IEEE80211_TX_CTL_DONTFRAG || + tx->local->ops->set_frag_threshold) && + !(tx->key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC)) { + /* hwaccel - with no need for SW-generated MMIC */ + return TX_CONTINUE; } -#if 0 - authenticator = fc & IEEE80211_FCTL_FROMDS; /* FIX */ -#else - authenticator = 1; -#endif - key = &tx->key->conf.key[authenticator ? ALG_TKIP_TEMP_AUTH_TX_MIC_KEY : - ALG_TKIP_TEMP_AUTH_RX_MIC_KEY]; + tail = MICHAEL_MIC_LEN; + if (!info->control.hw_key) + tail += IEEE80211_TKIP_ICV_LEN; + + if (WARN_ON(skb_tailroom(skb) < tail || + skb_headroom(skb) < IEEE80211_TKIP_IV_LEN)) + return TX_DROP; + + key = &tx->key->conf.key[NL80211_TKIP_DATA_OFFSET_TX_MIC_KEY]; mic = skb_put(skb, MICHAEL_MIC_LEN); - michael_mic(key, da, sa, qos_tid & 0x0f, data, data_len, mic); + michael_mic(key, hdr, data, data_len, mic); + if (unlikely(info->flags & IEEE80211_TX_INTFL_TKIP_MIC_FAILURE)) + mic[0]++; - return TXRX_CONTINUE; + return TX_CONTINUE; } -ieee80211_txrx_result -ieee80211_rx_h_michael_mic_verify(struct ieee80211_txrx_data *rx) +ieee80211_rx_result +ieee80211_rx_h_michael_mic_verify(struct ieee80211_rx_data *rx) { - u8 *data, *sa, *da, *key = NULL, qos_tid; + u8 *data, *key = NULL; size_t data_len; - u16 fc; + unsigned int hdrlen; u8 mic[MICHAEL_MIC_LEN]; struct sk_buff *skb = rx->skb; - int authenticator = 1, wpa_test = 0; - DECLARE_MAC_BUF(mac); + struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb); + struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data; + + /* + * it makes no sense to check for MIC errors on anything other + * than data frames. + */ + if (!ieee80211_is_data_present(hdr->frame_control)) + return RX_CONTINUE; + + /* + * No way to verify the MIC if the hardware stripped it or + * the IV with the key index. In this case we have solely rely + * on the driver to set RX_FLAG_MMIC_ERROR in the event of a + * MIC failure report. + */ + if (status->flag & (RX_FLAG_MMIC_STRIPPED | RX_FLAG_IV_STRIPPED)) { + if (status->flag & RX_FLAG_MMIC_ERROR) + goto mic_fail_no_key; + + if (!(status->flag & RX_FLAG_IV_STRIPPED) && rx->key && + rx->key->conf.cipher == WLAN_CIPHER_SUITE_TKIP) + goto update_iv; - fc = rx->fc; + return RX_CONTINUE; + } /* - * No way to verify the MIC if the hardware stripped it + * Some hardware seems to generate Michael MIC failure reports; even + * though, the frame was not encrypted with TKIP and therefore has no + * MIC. Ignore the flag them to avoid triggering countermeasures. */ - if (rx->u.rx.status->flag & RX_FLAG_MMIC_STRIPPED) - return TXRX_CONTINUE; - - if (!rx->key || rx->key->conf.alg != ALG_TKIP || - !(rx->fc & IEEE80211_FCTL_PROTECTED) || !WLAN_FC_DATA_PRESENT(fc)) - return TXRX_CONTINUE; - - if (ieee80211_get_hdr_info(skb, &sa, &da, &qos_tid, &data, &data_len) - || data_len < MICHAEL_MIC_LEN) - return TXRX_DROP; - - data_len -= MICHAEL_MIC_LEN; - -#if 0 - authenticator = fc & IEEE80211_FCTL_TODS; /* FIX */ -#else - authenticator = 1; -#endif - key = &rx->key->conf.key[authenticator ? ALG_TKIP_TEMP_AUTH_RX_MIC_KEY : - ALG_TKIP_TEMP_AUTH_TX_MIC_KEY]; - michael_mic(key, da, sa, qos_tid & 0x0f, data, data_len, mic); - if (memcmp(mic, data + data_len, MICHAEL_MIC_LEN) != 0 || wpa_test) { - if (!(rx->flags & IEEE80211_TXRXD_RXRA_MATCH)) - return TXRX_DROP; - - printk(KERN_DEBUG "%s: invalid Michael MIC in data frame from " - "%s\n", rx->dev->name, print_mac(mac, sa)); - - mac80211_ev_michael_mic_failure(rx->dev, rx->key->conf.keyidx, - (void *) skb->data); - return TXRX_DROP; + if (!rx->key || rx->key->conf.cipher != WLAN_CIPHER_SUITE_TKIP || + !(status->flag & RX_FLAG_DECRYPTED)) + return RX_CONTINUE; + + if (rx->sdata->vif.type == NL80211_IFTYPE_AP && rx->key->conf.keyidx) { + /* + * 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. + */ + return RX_DROP_UNUSABLE; } + if (status->flag & RX_FLAG_MMIC_ERROR) + goto mic_fail; + + hdrlen = ieee80211_hdrlen(hdr->frame_control); + 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]; + michael_mic(key, hdr, data, data_len, mic); + if (memcmp(mic, data + data_len, MICHAEL_MIC_LEN) != 0) + goto mic_fail; + /* remove Michael MIC from payload */ skb_trim(skb, skb->len - MICHAEL_MIC_LEN); +update_iv: /* update IV in key information to be able to detect replays */ - rx->key->u.tkip.iv32_rx[rx->u.rx.queue] = rx->u.rx.tkip_iv32; - rx->key->u.tkip.iv16_rx[rx->u.rx.queue] = rx->u.rx.tkip_iv16; + rx->key->u.tkip.rx[rx->security_idx].iv32 = rx->tkip_iv32; + rx->key->u.tkip.rx[rx->security_idx].iv16 = rx->tkip_iv16; + + return RX_CONTINUE; - return TXRX_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 + * the key is set. + */ + mac80211_ev_michael_mic_failure(rx->sdata, + rx->key ? rx->key->conf.keyidx : -1, + (void *) skb->data, NULL, GFP_ATOMIC); + return RX_DROP_UNUSABLE; } -static int tkip_encrypt_skb(struct ieee80211_txrx_data *tx, - struct sk_buff *skb, int test) +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; - int hdrlen, len, tailneed; - u16 fc; + struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); + unsigned int hdrlen; + int len, tail; u8 *pos; - fc = le16_to_cpu(hdr->frame_control); - hdrlen = ieee80211_get_hdrlen(fc); + 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)) { + /* hwaccel - with no need for software-generated IV */ + return 0; + } + + hdrlen = ieee80211_hdrlen(hdr->frame_control); len = skb->len - hdrlen; - if (tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) - tailneed = 0; + if (info->control.hw_key) + tail = 0; else - tailneed = TKIP_ICV_LEN; + tail = IEEE80211_TKIP_ICV_LEN; - if ((skb_headroom(skb) < TKIP_IV_LEN || - skb_tailroom(skb) < tailneed)) { - I802_DEBUG_INC(tx->local->tx_expand_skb_head); - if (unlikely(pskb_expand_head(skb, TKIP_IV_LEN, tailneed, - GFP_ATOMIC))) - return -1; - } + if (WARN_ON(skb_tailroom(skb) < tail || + 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; - /* Increase IV for the frame */ - key->u.tkip.iv16++; - if (key->u.tkip.iv16 == 0) - key->u.tkip.iv32++; - - if (tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) { - hdr = (struct ieee80211_hdr *)skb->data; - - /* hwaccel - with preallocated room for IV */ - ieee80211_tkip_add_iv(pos, key, - (u8) (key->u.tkip.iv16 >> 8), - (u8) (((key->u.tkip.iv16 >> 8) | 0x20) & - 0x7f), - (u8) key->u.tkip.iv16); + /* 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; - tx->u.tx.control->key_idx = tx->key->conf.hw_key_idx; + /* Increase IV for the frame */ + 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(&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); - hdr = (struct ieee80211_hdr *) skb->data; - ieee80211_tkip_encrypt_data(tx->local->wep_tx_tfm, - key, pos, len, hdr->addr2); - return 0; + return ieee80211_tkip_encrypt_data(tx->local->wep_tx_tfm, + key, skb, pos, len); } -ieee80211_txrx_result -ieee80211_crypto_tkip_encrypt(struct ieee80211_txrx_data *tx) +ieee80211_tx_result +ieee80211_crypto_tkip_encrypt(struct ieee80211_tx_data *tx) { - struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) tx->skb->data; - u16 fc; - struct sk_buff *skb = tx->skb; - int wpa_test = 0, test = 0; - - fc = le16_to_cpu(hdr->frame_control); - - if (!WLAN_FC_DATA_PRESENT(fc)) - return TXRX_CONTINUE; - - tx->u.tx.control->icv_len = TKIP_ICV_LEN; - tx->u.tx.control->iv_len = TKIP_IV_LEN; - ieee80211_tx_set_iswep(tx); - - if ((tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) && - !(tx->key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_IV) && - !wpa_test) { - /* hwaccel - with no need for preallocated room for IV/ICV */ - tx->u.tx.control->key_idx = tx->key->conf.hw_key_idx; - return TXRX_CONTINUE; - } + struct sk_buff *skb; - if (tkip_encrypt_skb(tx, skb, test) < 0) - return TXRX_DROP; + ieee80211_tx_set_protected(tx); - if (tx->u.tx.extra_frag) { - int i; - for (i = 0; i < tx->u.tx.num_extra_frag; i++) { - if (tkip_encrypt_skb(tx, tx->u.tx.extra_frag[i], test) - < 0) - return TXRX_DROP; - } + skb_queue_walk(&tx->skbs, skb) { + if (tkip_encrypt_skb(tx, skb) < 0) + return TX_DROP; } - return TXRX_CONTINUE; + return TX_CONTINUE; } -ieee80211_txrx_result -ieee80211_crypto_tkip_decrypt(struct ieee80211_txrx_data *rx) +ieee80211_rx_result +ieee80211_crypto_tkip_decrypt(struct ieee80211_rx_data *rx) { struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data; - u16 fc; - int hdrlen, res, hwaccel = 0, wpa_test = 0; + int hdrlen, res, hwaccel = 0; struct ieee80211_key *key = rx->key; struct sk_buff *skb = rx->skb; - DECLARE_MAC_BUF(mac); + struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb); - fc = le16_to_cpu(hdr->frame_control); - hdrlen = ieee80211_get_hdrlen(fc); + hdrlen = ieee80211_hdrlen(hdr->frame_control); - if ((rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA) - return TXRX_CONTINUE; + if (!ieee80211_is_data(hdr->frame_control)) + return RX_CONTINUE; if (!rx->sta || skb->len - hdrlen < 12) - return TXRX_DROP; - - if (rx->u.rx.status->flag & RX_FLAG_DECRYPTED) { - if (rx->u.rx.status->flag & RX_FLAG_IV_STRIPPED) { - /* - * Hardware took care of all processing, including - * replay protection, and stripped the ICV/IV so - * we cannot do any checks here. - */ - return TXRX_CONTINUE; - } + return RX_DROP_UNUSABLE; - /* let TKIP code verify IV, but skip decryption */ + /* 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, + * we don't even get here, see ieee80211_rx_h_decrypt() + */ + if (status->flag & RX_FLAG_DECRYPTED) hwaccel = 1; - } res = ieee80211_tkip_decrypt_data(rx->local->wep_rx_tfm, key, skb->data + hdrlen, - skb->len - hdrlen, rx->sta->addr, - hwaccel, rx->u.rx.queue, - &rx->u.rx.tkip_iv32, - &rx->u.rx.tkip_iv16); - if (res != TKIP_DECRYPT_OK || wpa_test) { - printk(KERN_DEBUG "%s: TKIP decrypt failed for RX frame from " - "%s (res=%d)\n", - rx->dev->name, print_mac(mac, rx->sta->addr), res); - return TXRX_DROP; - } + skb->len - hdrlen, rx->sta->sta.addr, + hdr->addr1, hwaccel, rx->security_idx, + &rx->tkip_iv32, + &rx->tkip_iv16); + if (res != TKIP_DECRYPT_OK) + 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 TXRX_CONTINUE; + return RX_CONTINUE; } -static void ccmp_special_blocks(struct sk_buff *skb, u8 *pn, u8 *b_0, u8 *aad, - int encrypted) +static void ccmp_special_blocks(struct sk_buff *skb, u8 *pn, u8 *b_0, u8 *aad) { - u16 fc; - int a4_included, qos_included; - u8 qos_tid, *fc_pos, *data, *sa, *da; - int len_a; - size_t data_len; - struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; + __le16 mask_fc; + int a4_included, mgmt; + u8 qos_tid; + u16 len_a; + unsigned int hdrlen; + struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data; - fc_pos = (u8 *) &hdr->frame_control; - fc = fc_pos[0] ^ (fc_pos[1] << 8); - a4_included = (fc & (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) == - (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS); - - ieee80211_get_hdr_info(skb, &sa, &da, &qos_tid, &data, &data_len); - data_len -= CCMP_HDR_LEN + (encrypted ? CCMP_MIC_LEN : 0); - if (qos_tid & 0x80) { - qos_included = 1; - qos_tid &= 0x0f; - } else - qos_included = 0; - /* First block, b_0 */ - - b_0[0] = 0x59; /* flags: Adata: 1, M: 011, L: 001 */ - /* Nonce: QoS Priority | A2 | PN */ - b_0[1] = qos_tid; - memcpy(&b_0[2], hdr->addr2, 6); - memcpy(&b_0[8], pn, CCMP_PN_LEN); - /* l(m) */ - b_0[14] = (data_len >> 8) & 0xff; - b_0[15] = data_len & 0xff; + /* + * Mask FC: zero subtype b4 b5 b6 (if not mgmt) + * Retry, PwrMgt, MoreData; set Protected + */ + mgmt = ieee80211_is_mgmt(hdr->frame_control); + mask_fc = hdr->frame_control; + mask_fc &= ~cpu_to_le16(IEEE80211_FCTL_RETRY | + IEEE80211_FCTL_PM | IEEE80211_FCTL_MOREDATA); + if (!mgmt) + mask_fc &= ~cpu_to_le16(0x0070); + mask_fc |= cpu_to_le16(IEEE80211_FCTL_PROTECTED); + + hdrlen = ieee80211_hdrlen(hdr->frame_control); + len_a = hdrlen - 2; + a4_included = ieee80211_has_a4(hdr->frame_control); + + if (ieee80211_is_data_qos(hdr->frame_control)) + qos_tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK; + else + qos_tid = 0; + + /* 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; + /* 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, IEEE80211_CCMP_PN_LEN); /* AAD (extra authenticate-only data) / masked 802.11 header * FC | A1 | A2 | A3 | SC | [A4] | [QC] */ - - len_a = a4_included ? 28 : 22; - if (qos_included) - len_a += 2; - - aad[0] = 0; /* (len_a >> 8) & 0xff; */ - aad[1] = len_a & 0xff; - /* Mask FC: zero subtype b4 b5 b6 */ - aad[2] = fc_pos[0] & ~(BIT(4) | BIT(5) | BIT(6)); - /* Retry, PwrMgt, MoreData; set Protected */ - aad[3] = (fc_pos[1] & ~(BIT(3) | BIT(4) | BIT(5))) | BIT(6); - memcpy(&aad[4], &hdr->addr1, 18); + put_unaligned_be16(len_a, &aad[0]); + 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 (a4_included) { - memcpy(&aad[24], hdr->addr4, 6); - aad[30] = 0; + memcpy(&aad[24], hdr->addr4, ETH_ALEN); + aad[30] = qos_tid; aad[31] = 0; - } else - memset(&aad[24], 0, 8); - if (qos_included) { - u8 *dpos = &aad[a4_included ? 30 : 24]; - - /* Mask QoS Control field */ - dpos[0] = qos_tid; - dpos[1] = 0; + } else { + memset(&aad[24], 0, ETH_ALEN + IEEE80211_QOS_CTL_LEN); + aad[24] = qos_tid; } } @@ -421,7 +381,7 @@ static inline void ccmp_pn2hdr(u8 *hdr, u8 *pn, int key_id) } -static inline int ccmp_hdr2pn(u8 *pn, u8 *hdr) +static inline void ccmp_hdr2pn(u8 *pn, u8 *hdr) { pn[0] = hdr[7]; pn[1] = hdr[6]; @@ -429,184 +389,430 @@ static inline int ccmp_hdr2pn(u8 *pn, u8 *hdr) pn[3] = hdr[4]; pn[4] = hdr[1]; pn[5] = hdr[0]; - return (hdr[3] >> 6) & 0x03; } -static int ccmp_encrypt_skb(struct ieee80211_txrx_data *tx, - struct sk_buff *skb, int test) +static int ccmp_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; - int hdrlen, len, tailneed; - u16 fc; - u8 *pos, *pn, *b_0, *aad, *scratch; - int i; - - scratch = key->u.ccmp.tx_crypto_buf; - b_0 = scratch + 3 * AES_BLOCK_LEN; - aad = scratch + 4 * AES_BLOCK_LEN; + 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 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_GENERATE_IV_MGMT) && + ieee80211_is_mgmt(hdr->frame_control))) { + /* + * hwaccel has no need for preallocated room for CCMP + * header or MIC fields + */ + return 0; + } - fc = le16_to_cpu(hdr->frame_control); - hdrlen = ieee80211_get_hdrlen(fc); + hdrlen = ieee80211_hdrlen(hdr->frame_control); len = skb->len - hdrlen; - if (key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) - tailneed = 0; + if (info->control.hw_key) + tail = 0; else - tailneed = CCMP_MIC_LEN; + tail = IEEE80211_CCMP_MIC_LEN; - if ((skb_headroom(skb) < CCMP_HDR_LEN || - skb_tailroom(skb) < tailneed)) { - I802_DEBUG_INC(tx->local->tx_expand_skb_head); - if (unlikely(pskb_expand_head(skb, CCMP_HDR_LEN, tailneed, - GFP_ATOMIC))) - return -1; - } + if (WARN_ON(skb_tailroom(skb) < tail || + skb_headroom(skb) < IEEE80211_CCMP_HDR_LEN)) + return -1; + + 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 && + (info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE)) + return 0; - pos = skb_push(skb, CCMP_HDR_LEN); - memmove(pos, pos + CCMP_HDR_LEN, hdrlen); hdr = (struct ieee80211_hdr *) pos; pos += hdrlen; - /* PN = PN + 1 */ - pn = key->u.ccmp.tx_pn; + pn64 = atomic64_inc_return(&key->u.ccmp.tx_pn); - for (i = CCMP_PN_LEN - 1; i >= 0; i--) { - pn[i]++; - if (pn[i]) - break; - } + pn[5] = pn64; + pn[4] = pn64 >> 8; + pn[3] = pn64 >> 16; + pn[2] = pn64 >> 24; + pn[1] = pn64 >> 32; + pn[0] = pn64 >> 40; ccmp_pn2hdr(pos, pn, key->conf.keyidx); - if (key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) { - /* hwaccel - with preallocated room for CCMP header */ - tx->u.tx.control->key_idx = key->conf.hw_key_idx; + /* hwaccel - with software CCMP header */ + if (info->control.hw_key) return 0; - } - pos += CCMP_HDR_LEN; - ccmp_special_blocks(skb, pn, b_0, aad, 0); - ieee80211_aes_ccm_encrypt(key->u.ccmp.tfm, scratch, b_0, aad, 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; } -ieee80211_txrx_result -ieee80211_crypto_ccmp_encrypt(struct ieee80211_txrx_data *tx) +ieee80211_tx_result +ieee80211_crypto_ccmp_encrypt(struct ieee80211_tx_data *tx) { - struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) tx->skb->data; - u16 fc; - struct sk_buff *skb = tx->skb; - int test = 0; + struct sk_buff *skb; + + ieee80211_tx_set_protected(tx); - fc = le16_to_cpu(hdr->frame_control); + skb_queue_walk(&tx->skbs, skb) { + if (ccmp_encrypt_skb(tx, skb) < 0) + return TX_DROP; + } - if (!WLAN_FC_DATA_PRESENT(fc)) - return TXRX_CONTINUE; + return TX_CONTINUE; +} - tx->u.tx.control->icv_len = CCMP_MIC_LEN; - tx->u.tx.control->iv_len = CCMP_HDR_LEN; - ieee80211_tx_set_iswep(tx); - if ((tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) && - !(tx->key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_IV)) { - /* hwaccel - with no need for preallocated room for CCMP " - * header or MIC fields */ - tx->u.tx.control->key_idx = tx->key->conf.hw_key_idx; - return TXRX_CONTINUE; +ieee80211_rx_result +ieee80211_crypto_ccmp_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_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(skb)) + return RX_CONTINUE; + + 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; } - if (ccmp_encrypt_skb(tx, skb, test) < 0) - return TXRX_DROP; + ccmp_hdr2pn(pn, skb->data + hdrlen); - if (tx->u.tx.extra_frag) { - int i; - for (i = 0; i < tx->u.tx.num_extra_frag; i++) { - if (ccmp_encrypt_skb(tx, tx->u.tx.extra_frag[i], test) - < 0) - return TXRX_DROP; - } + queue = rx->security_idx; + + if (memcmp(pn, key->u.ccmp.rx_pn[queue], IEEE80211_CCMP_PN_LEN) <= 0) { + key->u.ccmp.replays++; + return RX_DROP_UNUSABLE; } - return TXRX_CONTINUE; -} + if (!(status->flag & RX_FLAG_DECRYPTED)) { + u8 aad[2 * AES_BLOCK_SIZE]; + u8 b_0[AES_BLOCK_SIZE]; + /* hardware didn't decrypt/verify MIC */ + ccmp_special_blocks(skb, pn, b_0, aad); + if (ieee80211_aes_ccm_decrypt( + 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, IEEE80211_CCMP_PN_LEN); + + /* Remove CCMP header and MIC */ + 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); -ieee80211_txrx_result -ieee80211_crypto_ccmp_decrypt(struct ieee80211_txrx_data *rx) + 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 *) rx->skb->data; - u16 fc; + 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 sk_buff *skb = rx->skb; - u8 pn[CCMP_PN_LEN]; + 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; - DECLARE_MAC_BUF(mac); + u8 *rx_pn; + u8 *skb_pn; + u8 qos_tid; - fc = le16_to_cpu(hdr->frame_control); - hdrlen = ieee80211_get_hdrlen(fc); + if (!rx->sta || !rx->sta->cipher_scheme || + !(status->flag & RX_FLAG_DECRYPTED)) + return RX_DROP_UNUSABLE; - if ((rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA) - return TXRX_CONTINUE; + if (!ieee80211_is_data(hdr->frame_control)) + return RX_CONTINUE; - data_len = skb->len - hdrlen - CCMP_HDR_LEN - CCMP_MIC_LEN; - if (!rx->sta || data_len < 0) - return TXRX_DROP; + cs = rx->sta->cipher_scheme; - if ((rx->u.rx.status->flag & RX_FLAG_DECRYPTED) && - (rx->u.rx.status->flag & RX_FLAG_IV_STRIPPED)) - return TXRX_CONTINUE; + data_len = rx->skb->len - hdrlen - cs->hdr_len; - (void) ccmp_hdr2pn(pn, skb->data + hdrlen); + if (data_len < 0) + return RX_DROP_UNUSABLE; - if (memcmp(pn, key->u.ccmp.rx_pn[rx->u.rx.queue], CCMP_PN_LEN) <= 0) { -#ifdef CONFIG_MAC80211_DEBUG - u8 *ppn = key->u.ccmp.rx_pn[rx->u.rx.queue]; + if (ieee80211_is_data_qos(hdr->frame_control)) + qos_tid = *ieee80211_get_qos_ctl(hdr) & + IEEE80211_QOS_CTL_TID_MASK; + else + qos_tid = 0; - printk(KERN_DEBUG "%s: CCMP replay detected for RX frame from " - "%s (RX PN %02x%02x%02x%02x%02x%02x <= prev. PN " - "%02x%02x%02x%02x%02x%02x)\n", rx->dev->name, - print_mac(mac, rx->sta->addr), - pn[0], pn[1], pn[2], pn[3], pn[4], pn[5], - ppn[0], ppn[1], ppn[2], ppn[3], ppn[4], ppn[5]); -#endif /* CONFIG_MAC80211_DEBUG */ - key->u.ccmp.replays++; - return TXRX_DROP; + 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 */ + /* Mask FC Retry, PwrMgt, MoreData flags to zero */ + 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, &hdr->addr1, 3 * ETH_ALEN); +} + + +static inline void bip_ipn_set64(u8 *d, u64 pn) +{ + *d++ = pn; + *d++ = pn >> 8; + *d++ = pn >> 16; + *d++ = pn >> 24; + *d++ = pn >> 32; + *d = pn >> 40; +} + +static inline void bip_ipn_swap(u8 *d, const u8 *s) +{ + *d++ = s[5]; + *d++ = s[4]; + *d++ = s[3]; + *d++ = s[2]; + *d++ = s[1]; + *d = s[0]; +} + + +ieee80211_tx_result +ieee80211_crypto_aes_cmac_encrypt(struct ieee80211_tx_data *tx) +{ + struct sk_buff *skb; + struct ieee80211_tx_info *info; + struct ieee80211_key *key = tx->key; + struct ieee80211_mmie *mmie; + u8 aad[20]; + u64 pn64; + + if (WARN_ON(skb_queue_len(&tx->skbs) != 1)) + return TX_DROP; + + skb = skb_peek(&tx->skbs); + + info = IEEE80211_SKB_CB(skb); + + if (info->control.hw_key) + return TX_CONTINUE; + + 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; +} + + +ieee80211_rx_result +ieee80211_crypto_aes_cmac_decrypt(struct ieee80211_rx_data *rx) +{ + struct sk_buff *skb = rx->skb; + struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(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; + + /* management frames are already linear */ + + 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->u.rx.status->flag & RX_FLAG_DECRYPTED)) { + if (!(status->flag & RX_FLAG_DECRYPTED)) { /* hardware didn't decrypt/verify MIC */ - u8 *scratch, *b_0, *aad; + bip_aad(skb, aad); + ieee80211_aes_cmac(key->u.aes_cmac.tfm, 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; + } + } - scratch = key->u.ccmp.rx_crypto_buf; - b_0 = scratch + 3 * AES_BLOCK_LEN; - aad = scratch + 4 * AES_BLOCK_LEN; + memcpy(key->u.aes_cmac.rx_pn, ipn, 6); - ccmp_special_blocks(skb, pn, b_0, aad, 1); + /* Remove MMIE */ + skb_trim(skb, skb->len - sizeof(*mmie)); - if (ieee80211_aes_ccm_decrypt( - key->u.ccmp.tfm, scratch, b_0, aad, - skb->data + hdrlen + CCMP_HDR_LEN, data_len, - skb->data + skb->len - CCMP_MIC_LEN, - skb->data + hdrlen + CCMP_HDR_LEN)) { - printk(KERN_DEBUG "%s: CCMP decrypt failed for RX " - "frame from %s\n", rx->dev->name, - print_mac(mac, rx->sta->addr)); - return TXRX_DROP; + return RX_CONTINUE; +} + +ieee80211_tx_result +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); + + /* 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; } } - memcpy(key->u.ccmp.rx_pn[rx->u.rx.queue], pn, CCMP_PN_LEN); + ieee80211_tx_set_protected(tx); - /* 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); + 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 TXRX_CONTINUE; + return RX_DROP_UNUSABLE; } |