| /* |
| * Copyright 2002-2004, Instant802 Networks, Inc. |
| * |
| * 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/slab.h> |
| #include <linux/skbuff.h> |
| #include <linux/compiler.h> |
| #include <net/mac80211.h> |
| |
| #include "ieee80211_i.h" |
| #include "michael.h" |
| #include "tkip.h" |
| #include "aes_ccm.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) |
| { |
| struct ieee80211_hdr *hdr; |
| size_t hdrlen; |
| __le16 fc; |
| |
| hdr = (struct ieee80211_hdr *)skb->data; |
| fc = hdr->frame_control; |
| |
| hdrlen = ieee80211_hdrlen(fc); |
| |
| *sa = ieee80211_get_SA(hdr); |
| *da = ieee80211_get_DA(hdr); |
| |
| *data = skb->data + hdrlen; |
| *data_len = skb->len - hdrlen; |
| |
| if (ieee80211_is_data_qos(fc)) |
| *qos_tid = (*ieee80211_get_qos_ctl(hdr) & 0x0f) | 0x80; |
| else |
| *qos_tid = 0; |
| |
| return skb->len < hdrlen ? -1 : 0; |
| } |
| |
| |
| ieee80211_tx_result |
| ieee80211_tx_h_michael_mic_add(struct ieee80211_tx_data *tx) |
| { |
| u8 *data, *sa, *da, *key, *mic, qos_tid; |
| size_t data_len; |
| u16 fc; |
| struct sk_buff *skb = tx->skb; |
| int authenticator; |
| int wpa_test = 0; |
| int tail; |
| |
| fc = tx->fc; |
| |
| if (!tx->key || tx->key->conf.alg != ALG_TKIP || skb->len < 24 || |
| !WLAN_FC_DATA_PRESENT(fc)) |
| return TX_CONTINUE; |
| |
| if (ieee80211_get_hdr_info(skb, &sa, &da, &qos_tid, &data, &data_len)) |
| return TX_DROP; |
| |
| if ((tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) && |
| !(tx->flags & IEEE80211_TX_FRAGMENTED) && |
| !(tx->key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC) && |
| !wpa_test) { |
| /* hwaccel - with no need for preallocated room for Michael MIC |
| */ |
| return TX_CONTINUE; |
| } |
| |
| tail = MICHAEL_MIC_LEN; |
| if (!(tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE)) |
| tail += TKIP_ICV_LEN; |
| |
| if (WARN_ON(skb_tailroom(skb) < tail || |
| skb_headroom(skb) < TKIP_IV_LEN)) |
| return TX_DROP; |
| |
| #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]; |
| mic = skb_put(skb, MICHAEL_MIC_LEN); |
| michael_mic(key, da, sa, qos_tid & 0x0f, data, data_len, mic); |
| |
| return TX_CONTINUE; |
| } |
| |
| |
| ieee80211_rx_result |
| ieee80211_rx_h_michael_mic_verify(struct ieee80211_rx_data *rx) |
| { |
| u8 *data, *sa, *da, *key = NULL, qos_tid; |
| size_t data_len; |
| u16 fc; |
| u8 mic[MICHAEL_MIC_LEN]; |
| struct sk_buff *skb = rx->skb; |
| int authenticator = 1, wpa_test = 0; |
| DECLARE_MAC_BUF(mac); |
| |
| fc = rx->fc; |
| |
| /* |
| * No way to verify the MIC if the hardware stripped it |
| */ |
| if (rx->status->flag & RX_FLAG_MMIC_STRIPPED) |
| return RX_CONTINUE; |
| |
| if (!rx->key || rx->key->conf.alg != ALG_TKIP || |
| !(rx->fc & IEEE80211_FCTL_PROTECTED) || !WLAN_FC_DATA_PRESENT(fc)) |
| return RX_CONTINUE; |
| |
| if (ieee80211_get_hdr_info(skb, &sa, &da, &qos_tid, &data, &data_len) |
| || data_len < MICHAEL_MIC_LEN) |
| return RX_DROP_UNUSABLE; |
| |
| 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_RX_RA_MATCH)) |
| return RX_DROP_UNUSABLE; |
| |
| 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 RX_DROP_UNUSABLE; |
| } |
| |
| /* remove Michael MIC from payload */ |
| skb_trim(skb, skb->len - MICHAEL_MIC_LEN); |
| |
| /* 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; |
| |
| return RX_CONTINUE; |
| } |
| |
| |
| 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; |
| |
| info->control.icv_len = TKIP_ICV_LEN; |
| info->control.iv_len = TKIP_IV_LEN; |
| |
| 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 IV/ICV */ |
| info->control.hw_key = &tx->key->conf; |
| return 0; |
| } |
| |
| hdrlen = ieee80211_hdrlen(hdr->frame_control); |
| len = skb->len - hdrlen; |
| |
| if (tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) |
| tail = 0; |
| else |
| tail = TKIP_ICV_LEN; |
| |
| if (WARN_ON(skb_tailroom(skb) < tail || |
| skb_headroom(skb) < TKIP_IV_LEN)) |
| return -1; |
| |
| pos = skb_push(skb, TKIP_IV_LEN); |
| memmove(pos, pos + TKIP_IV_LEN, hdrlen); |
| pos += hdrlen; |
| |
| /* Increase IV for the frame */ |
| key->u.tkip.tx.iv16++; |
| if (key->u.tkip.tx.iv16 == 0) |
| key->u.tkip.tx.iv32++; |
| |
| if (tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) { |
| /* hwaccel - with preallocated room for IV */ |
| ieee80211_tkip_add_iv(pos, key, key->u.tkip.tx.iv16); |
| |
| info->control.hw_key = &tx->key->conf; |
| return 0; |
| } |
| |
| /* Add room for ICV */ |
| skb_put(skb, 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; |
| } |
| |
| |
| ieee80211_tx_result |
| ieee80211_crypto_tkip_encrypt(struct ieee80211_tx_data *tx) |
| { |
| struct sk_buff *skb = tx->skb; |
| |
| ieee80211_tx_set_protected(tx); |
| |
| if (tkip_encrypt_skb(tx, skb) < 0) |
| return TX_DROP; |
| |
| if (tx->extra_frag) { |
| int i; |
| for (i = 0; i < tx->num_extra_frag; i++) { |
| if (tkip_encrypt_skb(tx, tx->extra_frag[i]) < 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, wpa_test = 0; |
| struct ieee80211_key *key = rx->key; |
| struct sk_buff *skb = rx->skb; |
| DECLARE_MAC_BUF(mac); |
| |
| hdrlen = ieee80211_hdrlen(hdr->frame_control); |
| |
| if ((rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA) |
| return RX_CONTINUE; |
| |
| if (!rx->sta || skb->len - hdrlen < 12) |
| return RX_DROP_UNUSABLE; |
| |
| if (rx->status->flag & RX_FLAG_DECRYPTED) { |
| if (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 RX_CONTINUE; |
| } |
| |
| /* let TKIP code verify IV, but skip decryption */ |
| hwaccel = 1; |
| } |
| |
| res = ieee80211_tkip_decrypt_data(rx->local->wep_rx_tfm, |
| key, skb->data + hdrlen, |
| skb->len - hdrlen, rx->sta->addr, |
| hdr->addr1, hwaccel, rx->queue, |
| &rx->tkip_iv32, |
| &rx->tkip_iv16); |
| if (res != TKIP_DECRYPT_OK || wpa_test) { |
| #ifdef CONFIG_MAC80211_DEBUG |
| if (net_ratelimit()) |
| 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); |
| #endif /* CONFIG_MAC80211_DEBUG */ |
| return RX_DROP_UNUSABLE; |
| } |
| |
| /* Trim ICV */ |
| skb_trim(skb, skb->len - TKIP_ICV_LEN); |
| |
| /* Remove IV */ |
| memmove(skb->data + TKIP_IV_LEN, skb->data, hdrlen); |
| skb_pull(skb, TKIP_IV_LEN); |
| |
| return RX_CONTINUE; |
| } |
| |
| |
| static void ccmp_special_blocks(struct sk_buff *skb, u8 *pn, u8 *b_0, u8 *aad, |
| int encrypted) |
| { |
| 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; |
| |
| 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; |
| |
| |
| /* 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); |
| |
| /* 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; |
| 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; |
| } |
| } |
| |
| |
| 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 int 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]; |
| return (hdr[3] >> 6) & 0x03; |
| } |
| |
| |
| 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; |
| struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); |
| int hdrlen, len, tail; |
| u8 *pos, *pn, *b_0, *aad, *scratch; |
| int i; |
| |
| info->control.icv_len = CCMP_MIC_LEN; |
| info->control.iv_len = CCMP_HDR_LEN; |
| |
| 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 */ |
| info->control.hw_key = &tx->key->conf; |
| return 0; |
| } |
| |
| scratch = key->u.ccmp.tx_crypto_buf; |
| b_0 = scratch + 3 * AES_BLOCK_LEN; |
| aad = scratch + 4 * AES_BLOCK_LEN; |
| |
| hdrlen = ieee80211_hdrlen(hdr->frame_control); |
| len = skb->len - hdrlen; |
| |
| if (key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) |
| tail = 0; |
| else |
| tail = CCMP_MIC_LEN; |
| |
| if (WARN_ON(skb_tailroom(skb) < tail || |
| skb_headroom(skb) < CCMP_HDR_LEN)) |
| return -1; |
| |
| 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; |
| |
| for (i = CCMP_PN_LEN - 1; i >= 0; i--) { |
| pn[i]++; |
| if (pn[i]) |
| break; |
| } |
| |
| ccmp_pn2hdr(pos, pn, key->conf.keyidx); |
| |
| if (key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) { |
| /* hwaccel - with preallocated room for CCMP header */ |
| info->control.hw_key = &tx->key->conf; |
| 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)); |
| |
| return 0; |
| } |
| |
| |
| ieee80211_tx_result |
| ieee80211_crypto_ccmp_encrypt(struct ieee80211_tx_data *tx) |
| { |
| struct sk_buff *skb = tx->skb; |
| |
| ieee80211_tx_set_protected(tx); |
| |
| if (ccmp_encrypt_skb(tx, skb) < 0) |
| return TX_DROP; |
| |
| if (tx->extra_frag) { |
| int i; |
| for (i = 0; i < tx->num_extra_frag; i++) { |
| if (ccmp_encrypt_skb(tx, tx->extra_frag[i]) < 0) |
| return TX_DROP; |
| } |
| } |
| |
| return TX_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; |
| u8 pn[CCMP_PN_LEN]; |
| int data_len; |
| DECLARE_MAC_BUF(mac); |
| |
| hdrlen = ieee80211_hdrlen(hdr->frame_control); |
| |
| if ((rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA) |
| return RX_CONTINUE; |
| |
| data_len = skb->len - hdrlen - CCMP_HDR_LEN - CCMP_MIC_LEN; |
| if (!rx->sta || data_len < 0) |
| return RX_DROP_UNUSABLE; |
| |
| if ((rx->status->flag & RX_FLAG_DECRYPTED) && |
| (rx->status->flag & RX_FLAG_IV_STRIPPED)) |
| return RX_CONTINUE; |
| |
| (void) ccmp_hdr2pn(pn, skb->data + hdrlen); |
| |
| if (memcmp(pn, key->u.ccmp.rx_pn[rx->queue], CCMP_PN_LEN) <= 0) { |
| #ifdef CONFIG_MAC80211_DEBUG |
| u8 *ppn = key->u.ccmp.rx_pn[rx->queue]; |
| |
| 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 RX_DROP_UNUSABLE; |
| } |
| |
| if (!(rx->status->flag & RX_FLAG_DECRYPTED)) { |
| /* hardware didn't decrypt/verify MIC */ |
| u8 *scratch, *b_0, *aad; |
| |
| scratch = key->u.ccmp.rx_crypto_buf; |
| b_0 = scratch + 3 * AES_BLOCK_LEN; |
| aad = scratch + 4 * AES_BLOCK_LEN; |
| |
| ccmp_special_blocks(skb, pn, b_0, aad, 1); |
| |
| 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)) { |
| #ifdef CONFIG_MAC80211_DEBUG |
| if (net_ratelimit()) |
| printk(KERN_DEBUG "%s: CCMP decrypt failed " |
| "for RX frame from %s\n", rx->dev->name, |
| print_mac(mac, rx->sta->addr)); |
| #endif /* CONFIG_MAC80211_DEBUG */ |
| return RX_DROP_UNUSABLE; |
| } |
| } |
| |
| memcpy(key->u.ccmp.rx_pn[rx->queue], pn, 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); |
| |
| return RX_CONTINUE; |
| } |