diff options
Diffstat (limited to 'net/mac80211/wpa.c')
| -rw-r--r-- | net/mac80211/wpa.c | 1238 |
1 files changed, 1238 insertions, 0 deletions
diff --git a/net/mac80211/wpa.c b/net/mac80211/wpa.c new file mode 100644 index 000000000..9d63d93c8 --- /dev/null +++ b/net/mac80211/wpa.c @@ -0,0 +1,1238 @@ +/* + * 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 + * published by the Free Software Foundation. + */ + +#include <linux/netdevice.h> +#include <linux/types.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 "aes_gmac.h" +#include "aes_gcm.h" +#include "wpa.h" + +ieee80211_tx_result +ieee80211_tx_h_michael_mic_add(struct ieee80211_tx_data *tx) +{ + 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 tail; + + 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; + + hdrlen = ieee80211_hdrlen(hdr->frame_control); + if (skb->len < hdrlen) + return TX_DROP; + + 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 && + (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; + } + + tail = MICHAEL_MIC_LEN; + if (!info->control.hw_key) + tail += IEEE80211_TKIP_ICV_LEN; + + if (WARN(skb_tailroom(skb) < tail || + skb_headroom(skb) < IEEE80211_TKIP_IV_LEN, + "mmic: not enough head/tail (%d/%d,%d/%d)\n", + skb_headroom(skb), IEEE80211_TKIP_IV_LEN, + skb_tailroom(skb), tail)) + 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, hdr, data, data_len, mic); + if (unlikely(info->flags & IEEE80211_TX_INTFL_TKIP_MIC_FAILURE)) + mic[0]++; + + return TX_CONTINUE; +} + + +ieee80211_rx_result +ieee80211_rx_h_michael_mic_verify(struct ieee80211_rx_data *rx) +{ + 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; + + /* + * 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 || + !(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.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; +} + + +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 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_PUT_IV_SPACE)) { + /* hwaccel - with no need for software-generated IV */ + return 0; + } + + hdrlen = ieee80211_hdrlen(hdr->frame_control); + len = skb->len - hdrlen; + + if (info->control.hw_key) + tail = 0; + else + tail = IEEE80211_TKIP_ICV_LEN; + + if (WARN_ON(skb_tailroom(skb) < tail || + skb_headroom(skb) < IEEE80211_TKIP_IV_LEN)) + return -1; + + pos = skb_push(skb, IEEE80211_TKIP_IV_LEN); + memmove(pos, pos + IEEE80211_TKIP_IV_LEN, hdrlen); + 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); + spin_unlock(&key->u.tkip.txlock); + + /* hwaccel - with software IV */ + if (info->control.hw_key) + return 0; + + /* Add room for ICV */ + skb_put(skb, IEEE80211_TKIP_ICV_LEN); + + return ieee80211_tkip_encrypt_data(tx->local->wep_tx_tfm, + key, skb, pos, len); +} + + +ieee80211_tx_result +ieee80211_crypto_tkip_encrypt(struct ieee80211_tx_data *tx) +{ + struct sk_buff *skb; + + ieee80211_tx_set_protected(tx); + + skb_queue_walk(&tx->skbs, skb) { + if (tkip_encrypt_skb(tx, skb) < 0) + return TX_DROP; + } + + return TX_CONTINUE; +} + + +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; + struct ieee80211_key *key = rx->key; + struct sk_buff *skb = rx->skb; + struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb); + + hdrlen = ieee80211_hdrlen(hdr->frame_control); + + if (!ieee80211_is_data(hdr->frame_control)) + return RX_CONTINUE; + + 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, + * 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->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 - IEEE80211_TKIP_ICV_LEN); + + /* Remove IV */ + 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 *b_0, u8 *aad) +{ + __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; + + /* + * 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] */ + 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, 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 ccmp_pn2hdr(u8 *hdr, 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 ccmp_hdr2pn(u8 *pn, 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 ccmp_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb, + unsigned int mic_len) +{ + 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 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; + } + + hdrlen = ieee80211_hdrlen(hdr->frame_control); + len = skb->len - hdrlen; + + if (info->control.hw_key) + tail = 0; + else + tail = mic_len; + + 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); + + /* 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.ccmp.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; + + ccmp_pn2hdr(pos, pn, key->conf.keyidx); + + /* hwaccel - with software CCMP header */ + if (info->control.hw_key) + return 0; + + 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, mic_len), mic_len); + + return 0; +} + + +ieee80211_tx_result +ieee80211_crypto_ccmp_encrypt(struct ieee80211_tx_data *tx, + unsigned int mic_len) +{ + struct sk_buff *skb; + + ieee80211_tx_set_protected(tx); + + skb_queue_walk(&tx->skbs, skb) { + if (ccmp_encrypt_skb(tx, skb, mic_len) < 0) + return TX_DROP; + } + + return TX_CONTINUE; +} + + +ieee80211_rx_result +ieee80211_crypto_ccmp_decrypt(struct ieee80211_rx_data *rx, + unsigned int mic_len) +{ + 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 - 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], 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, 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 - mic_len, 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 - 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 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) +{ + 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; + u8 *pos, iv_len = key->conf.iv_len; + + 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) < iv_len && + pskb_expand_head(skb, iv_len, 0, GFP_ATOMIC))) + return TX_DROP; + + hdrlen = ieee80211_hdrlen(hdr->frame_control); + + pos = skb_push(skb, iv_len); + memmove(pos, pos + iv_len, hdrlen); + + 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 */ + /* 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_tx_result +ieee80211_crypto_aes_cmac_256_encrypt(struct ieee80211_tx_data *tx) +{ + struct sk_buff *skb; + struct ieee80211_tx_info *info; + struct ieee80211_key *key = tx->key; + struct ieee80211_mmie_16 *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_16 *)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-256-CMAC(IGTK, AAD || Management Frame Body || MMIE, 128) + */ + ieee80211_aes_cmac_256(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 (!(status->flag & RX_FLAG_DECRYPTED)) { + /* hardware didn't decrypt/verify MIC */ + 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; + } + } + + memcpy(key->u.aes_cmac.rx_pn, ipn, 6); + + /* Remove MMIE */ + skb_trim(skb, skb->len - sizeof(*mmie)); + + return RX_CONTINUE; +} + +ieee80211_rx_result +ieee80211_crypto_aes_cmac_256_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_16 *mmie; + u8 aad[20], mic[16], 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_16 *) + (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 (!(status->flag & RX_FLAG_DECRYPTED)) { + /* hardware didn't decrypt/verify MIC */ + bip_aad(skb, aad); + ieee80211_aes_cmac_256(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; + } + } + + 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_gmac_encrypt(struct ieee80211_tx_data *tx) +{ + struct sk_buff *skb; + struct ieee80211_tx_info *info; + struct ieee80211_key *key = tx->key; + struct ieee80211_mmie_16 *mmie; + struct ieee80211_hdr *hdr; + u8 aad[20]; + u64 pn64; + u8 nonce[12]; + + 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_16 *)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_gmac.tx_pn); + + bip_ipn_set64(mmie->sequence_number, pn64); + + bip_aad(skb, aad); + + hdr = (struct ieee80211_hdr *)skb->data; + memcpy(nonce, hdr->addr2, ETH_ALEN); + bip_ipn_swap(nonce + ETH_ALEN, mmie->sequence_number); + + /* MIC = AES-GMAC(IGTK, AAD || Management Frame Body || MMIE, 128) */ + if (ieee80211_aes_gmac(key->u.aes_gmac.tfm, aad, nonce, + skb->data + 24, skb->len - 24, mmie->mic) < 0) + return TX_DROP; + + return TX_CONTINUE; +} + +ieee80211_rx_result +ieee80211_crypto_aes_gmac_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_16 *mmie; + u8 aad[20], mic[16], ipn[6], nonce[12]; + 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_16 *) + (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_gmac.rx_pn, 6) <= 0) { + key->u.aes_gmac.replays++; + return RX_DROP_UNUSABLE; + } + + if (!(status->flag & RX_FLAG_DECRYPTED)) { + /* hardware didn't decrypt/verify MIC */ + bip_aad(skb, aad); + + memcpy(nonce, hdr->addr2, ETH_ALEN); + memcpy(nonce + ETH_ALEN, ipn, 6); + + if (ieee80211_aes_gmac(key->u.aes_gmac.tfm, aad, nonce, + skb->data + 24, skb->len - 24, + mic) < 0 || + memcmp(mic, mmie->mic, sizeof(mmie->mic)) != 0) { + key->u.aes_gmac.icverrors++; + return RX_DROP_UNUSABLE; + } + } + + memcpy(key->u.aes_gmac.rx_pn, ipn, 6); + + /* Remove MMIE */ + skb_trim(skb, skb->len - sizeof(*mmie)); + + 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->flags & KEY_FLAG_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 && rx->sta->cipher_scheme) + return ieee80211_crypto_cs_decrypt(rx); + + return RX_DROP_UNUSABLE; +} |