diff options
Diffstat (limited to 'net/mac80211/wpa.c')
| -rw-r--r-- | net/mac80211/wpa.c | 487 |
1 files changed, 357 insertions, 130 deletions
diff --git a/net/mac80211/wpa.c b/net/mac80211/wpa.c index bee230d8fd1..9b3dcc20114 100644 --- a/net/mac80211/wpa.c +++ b/net/mac80211/wpa.c @@ -15,6 +15,7 @@ #include <linux/gfp.h> #include <asm/unaligned.h> #include <net/mac80211.h> +#include <crypto/aes.h> #include "ieee80211_i.h" #include "michael.h" @@ -26,13 +27,12 @@ ieee80211_tx_result ieee80211_tx_h_michael_mic_add(struct ieee80211_tx_data *tx) { - u8 *data, *key, *mic, key_offset; + u8 *data, *key, *mic; size_t data_len; unsigned int hdrlen; struct ieee80211_hdr *hdr; struct sk_buff *skb = tx->skb; struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); - int authenticator; int tail; hdr = (struct ieee80211_hdr *)skb->data; @@ -47,8 +47,14 @@ ieee80211_tx_h_michael_mic_add(struct ieee80211_tx_data *tx) data = skb->data + hdrlen; data_len = skb->len - hdrlen; + if (unlikely(info->flags & IEEE80211_TX_INTFL_TKIP_MIC_FAILURE)) { + /* Need to use software crypto for the test */ + info->control.hw_key = NULL; + } + if (info->control.hw_key && - !(tx->flags & IEEE80211_TX_FRAGMENTED) && + (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; @@ -56,23 +62,17 @@ 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; -#if 0 - authenticator = fc & IEEE80211_FCTL_FROMDS; /* FIX */ -#else - authenticator = 1; -#endif - key_offset = authenticator ? - NL80211_TKIP_DATA_OFFSET_TX_MIC_KEY : - NL80211_TKIP_DATA_OFFSET_RX_MIC_KEY; - key = &tx->key->conf.key[key_offset]; + key = &tx->key->conf.key[NL80211_TKIP_DATA_OFFSET_TX_MIC_KEY]; mic = skb_put(skb, MICHAEL_MIC_LEN); michael_mic(key, hdr, data, data_len, mic); + if (unlikely(info->flags & IEEE80211_TX_INTFL_TKIP_MIC_FAILURE)) + mic[0]++; return TX_CONTINUE; } @@ -81,59 +81,98 @@ ieee80211_tx_h_michael_mic_add(struct ieee80211_tx_data *tx) ieee80211_rx_result ieee80211_rx_h_michael_mic_verify(struct ieee80211_rx_data *rx) { - u8 *data, *key = NULL, key_offset; + u8 *data, *key = NULL; size_t data_len; unsigned int hdrlen; u8 mic[MICHAEL_MIC_LEN]; struct sk_buff *skb = rx->skb; struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb); struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data; - int authenticator = 1, wpa_test = 0; - /* No way to verify the MIC if the hardware stripped it */ - if (status->flag & RX_FLAG_MMIC_STRIPPED) + /* + * 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; + + return RX_CONTINUE; + } + + /* + * 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->key || rx->key->conf.cipher != WLAN_CIPHER_SUITE_TKIP || - !ieee80211_has_protected(hdr->frame_control) || - !ieee80211_is_data_present(hdr->frame_control)) + !(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; - -#if 0 - authenticator = fc & IEEE80211_FCTL_TODS; /* FIX */ -#else - authenticator = 1; -#endif - key_offset = authenticator ? - NL80211_TKIP_DATA_OFFSET_RX_MIC_KEY : - NL80211_TKIP_DATA_OFFSET_TX_MIC_KEY; - key = &rx->key->conf.key[key_offset]; + 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 || wpa_test) { - if (!(status->rx_flags & IEEE80211_RX_RA_MATCH)) - return RX_DROP_UNUSABLE; - - mac80211_ev_michael_mic_failure(rx->sdata, rx->key->conf.keyidx, - (void *) skb->data, NULL, - GFP_ATOMIC); - return RX_DROP_UNUSABLE; - } + 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.rx[rx->queue].iv32 = rx->tkip_iv32; - rx->key->u.tkip.rx[rx->queue].iv16 = 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; + +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; } @@ -147,7 +186,8 @@ static int tkip_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb) 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; } @@ -158,47 +198,54 @@ 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(&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, key->u.tkip.tx.iv16); + 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; return ieee80211_tkip_encrypt_data(tx->local->wep_tx_tfm, - key, pos, len, hdr->addr2); + key, skb, pos, len); } ieee80211_tx_result ieee80211_crypto_tkip_encrypt(struct ieee80211_tx_data *tx) { - struct sk_buff *skb = tx->skb; + struct sk_buff *skb; ieee80211_tx_set_protected(tx); - do { + skb_queue_walk(&tx->skbs, skb) { if (tkip_encrypt_skb(tx, skb) < 0) return TX_DROP; - } while ((skb = skb->next)); + } return TX_CONTINUE; } @@ -208,7 +255,7 @@ ieee80211_rx_result ieee80211_crypto_tkip_decrypt(struct ieee80211_rx_data *rx) { struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data; - 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; struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb); @@ -221,6 +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, @@ -232,37 +284,32 @@ ieee80211_crypto_tkip_decrypt(struct ieee80211_rx_data *rx) res = ieee80211_tkip_decrypt_data(rx->local->wep_rx_tfm, key, skb->data + hdrlen, skb->len - hdrlen, rx->sta->sta.addr, - hdr->addr1, hwaccel, rx->queue, + hdr->addr1, hwaccel, rx->security_idx, &rx->tkip_iv32, &rx->tkip_iv16); - if (res != TKIP_DECRYPT_OK || wpa_test) + 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 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; - b_0 = scratch + 3 * AES_BLOCK_LEN; - aad = scratch + 4 * AES_BLOCK_LEN; - /* * Mask FC: zero subtype b4 b5 b6 (if not mgmt) * Retry, PwrMgt, MoreData; set Protected @@ -284,20 +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] */ @@ -350,11 +398,18 @@ static int ccmp_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb) struct ieee80211_key *key = tx->key; struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); int hdrlen, len, tail; - u8 *pos, *pn; - int i; + 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_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 @@ -368,25 +423,33 @@ 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 && + (info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE)) + return 0; + 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); @@ -394,10 +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, key->u.ccmp.tx_crypto_buf, 0); - ieee80211_aes_ccm_encrypt(key->u.ccmp.tfm, key->u.ccmp.tx_crypto_buf, 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; } @@ -406,14 +469,14 @@ static int ccmp_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb) ieee80211_tx_result ieee80211_crypto_ccmp_encrypt(struct ieee80211_tx_data *tx) { - struct sk_buff *skb = tx->skb; + struct sk_buff *skb; ieee80211_tx_set_protected(tx); - do { + skb_queue_walk(&tx->skbs, skb) { if (ccmp_encrypt_skb(tx, skb) < 0) return TX_DROP; - } while ((skb = skb->next)); + } return TX_CONTINUE; } @@ -427,66 +490,192 @@ 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 = ieee80211_is_mgmt(hdr->frame_control) ? - NUM_RX_DATA_QUEUES : rx->queue; + 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 aad[2 * AES_BLOCK_SIZE]; + u8 b_0[AES_BLOCK_SIZE]; /* hardware didn't decrypt/verify MIC */ - ccmp_special_blocks(skb, pn, key->u.ccmp.rx_crypto_buf, 1); + ccmp_special_blocks(skb, pn, b_0, aad); if (ieee80211_aes_ccm_decrypt( - key->u.ccmp.tfm, key->u.ccmp.rx_crypto_buf, - 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); } +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]; @@ -501,15 +690,22 @@ static inline void bip_ipn_swap(u8 *d, const u8 *s) 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 sk_buff *skb; + struct ieee80211_tx_info *info; struct ieee80211_key *key = tx->key; struct ieee80211_mmie *mmie; - u8 *pn, aad[20]; - int i; + 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 0; + return TX_CONTINUE; if (WARN_ON(skb_tailroom(skb) < sizeof(*mmie))) return TX_DROP; @@ -520,22 +716,17 @@ ieee80211_crypto_aes_cmac_encrypt(struct ieee80211_tx_data *tx) mmie->key_id = cpu_to_le16(key->conf.keyidx); /* PN = PN + 1 */ - pn = key->u.aes_cmac.tx_pn; + pn64 = atomic64_inc_return(&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_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, key->u.aes_cmac.tx_crypto_buf, - aad, skb->data + 24, skb->len - 24, mmie->mic); + ieee80211_aes_cmac(key->u.aes_cmac.tfm, aad, + skb->data + 24, skb->len - 24, mmie->mic); return TX_CONTINUE; } @@ -554,6 +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; @@ -573,8 +766,7 @@ ieee80211_crypto_aes_cmac_decrypt(struct ieee80211_rx_data *rx) if (!(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, + 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++; @@ -589,3 +781,38 @@ ieee80211_crypto_aes_cmac_decrypt(struct ieee80211_rx_data *rx) 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; + } + } + + 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; +} |
