diff options
Diffstat (limited to 'net/mac80211/wpa.c')
| -rw-r--r-- | net/mac80211/wpa.c | 152 |
1 files changed, 144 insertions, 8 deletions
diff --git a/net/mac80211/wpa.c b/net/mac80211/wpa.c index 7aa63caf8d50..9101b48ec2ae 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 @@ -19,6 +20,7 @@ #include "michael.h" #include "tkip.h" #include "aes_ccm.h" +#include "aes_cmac.h" #include "wpa.h" ieee80211_tx_result @@ -266,7 +268,7 @@ static void ccmp_special_blocks(struct sk_buff *skb, u8 *pn, u8 *scratch, int encrypted) { __le16 mask_fc; - int a4_included; + int a4_included, mgmt; u8 qos_tid; u8 *b_0, *aad; u16 data_len, len_a; @@ -277,12 +279,15 @@ static void ccmp_special_blocks(struct sk_buff *skb, u8 *pn, u8 *scratch, aad = scratch + 4 * AES_BLOCK_LEN; /* - * Mask FC: zero subtype b4 b5 b6 + * 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(0x0070 | IEEE80211_FCTL_RETRY | + 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); @@ -300,8 +305,10 @@ static void ccmp_special_blocks(struct sk_buff *skb, u8 *pn, u8 *scratch, /* 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; + /* 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) */ @@ -360,9 +367,14 @@ static int ccmp_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb) int hdrlen, len, tail; u8 *pos, *pn; int i; + bool skip_hw; + + skip_hw = (tx->key->conf.flags & IEEE80211_KEY_FLAG_SW_MGMT) && + ieee80211_is_mgmt(hdr->frame_control); if ((tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) && - !(tx->key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_IV)) { + !(tx->key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_IV) && + !skip_hw) { /* hwaccel - with no need for preallocated room for CCMP * header or MIC fields */ info->control.hw_key = &tx->key->conf; @@ -397,7 +409,7 @@ static int ccmp_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb) ccmp_pn2hdr(pos, pn, key->conf.keyidx); - if (key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) { + if ((key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) && !skip_hw) { /* hwaccel - with preallocated room for CCMP header */ info->control.hw_key = &tx->key->conf; return 0; @@ -446,7 +458,8 @@ ieee80211_crypto_ccmp_decrypt(struct ieee80211_rx_data *rx) hdrlen = ieee80211_hdrlen(hdr->frame_control); - if (!ieee80211_is_data(hdr->frame_control)) + if (!ieee80211_is_data(hdr->frame_control) && + !ieee80211_is_robust_mgmt_frame(hdr)) return RX_CONTINUE; data_len = skb->len - hdrlen - CCMP_HDR_LEN - CCMP_MIC_LEN; @@ -485,3 +498,126 @@ ieee80211_crypto_ccmp_decrypt(struct ieee80211_rx_data *rx) return RX_CONTINUE; } + + +static void bip_aad(struct sk_buff *skb, u8 *aad) +{ + /* 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)); + /* A1 || A2 || A3 */ + memcpy(aad + 2, skb->data + 4, 3 * ETH_ALEN); +} + + +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 = tx->skb; + struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); + struct ieee80211_key *key = tx->key; + struct ieee80211_mmie *mmie; + u8 *pn, aad[20]; + int i; + + if (tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) { + /* hwaccel */ + info->control.hw_key = &tx->key->conf; + return 0; + } + + 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 */ + pn = 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_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); + + return TX_CONTINUE; +} + + +ieee80211_rx_result +ieee80211_crypto_aes_cmac_decrypt(struct ieee80211_rx_data *rx) +{ + struct sk_buff *skb = rx->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; + + if ((rx->status->flag & RX_FLAG_DECRYPTED) && + (rx->status->flag & RX_FLAG_IV_STRIPPED)) + return RX_CONTINUE; + + 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->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, + 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; +} |