/* * Host AP crypt: host-based TKIP encryption implementation for Host AP driver * * Copyright (c) 2003-2004, 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. See README and COPYING for * more details. */ #include <linux/err.h> #include <linux/module.h> #include <linux/init.h> #include <linux/slab.h> #include <linux/random.h> #include <linux/scatterlist.h> #include <linux/skbuff.h> #include <linux/netdevice.h> #include <linux/mm.h> #include <linux/if_ether.h> #include <linux/if_arp.h> #include <asm/string.h> #include <net/ieee80211.h> #include <linux/crypto.h> #include <linux/crc32.h> MODULE_AUTHOR("Jouni Malinen"); MODULE_DESCRIPTION("Host AP crypt: TKIP"); MODULE_LICENSE("GPL"); struct ieee80211_tkip_data { #define TKIP_KEY_LEN 32 u8 key[TKIP_KEY_LEN]; int key_set; u32 tx_iv32; u16 tx_iv16; u16 tx_ttak[5]; int tx_phase1_done; u32 rx_iv32; u16 rx_iv16; u16 rx_ttak[5]; int rx_phase1_done; u32 rx_iv32_new; u16 rx_iv16_new; u32 dot11RSNAStatsTKIPReplays; u32 dot11RSNAStatsTKIPICVErrors; u32 dot11RSNAStatsTKIPLocalMICFailures; int key_idx; struct crypto_blkcipher *rx_tfm_arc4; struct crypto_hash *rx_tfm_michael; struct crypto_blkcipher *tx_tfm_arc4; struct crypto_hash *tx_tfm_michael; /* scratch buffers for virt_to_page() (crypto API) */ u8 rx_hdr[16], tx_hdr[16]; unsigned long flags; }; static unsigned long ieee80211_tkip_set_flags(unsigned long flags, void *priv) { struct ieee80211_tkip_data *_priv = priv; unsigned long old_flags = _priv->flags; _priv->flags = flags; return old_flags; } static unsigned long ieee80211_tkip_get_flags(void *priv) { struct ieee80211_tkip_data *_priv = priv; return _priv->flags; } static void *ieee80211_tkip_init(int key_idx) { struct ieee80211_tkip_data *priv; priv = kzalloc(sizeof(*priv), GFP_ATOMIC); if (priv == NULL) goto fail; priv->key_idx = key_idx; priv->tx_tfm_arc4 = crypto_alloc_blkcipher("ecb(arc4)", 0, CRYPTO_ALG_ASYNC); if (IS_ERR(priv->tx_tfm_arc4)) { printk(KERN_DEBUG "ieee80211_crypt_tkip: could not allocate " "crypto API arc4\n"); priv->tx_tfm_arc4 = NULL; goto fail; } priv->tx_tfm_michael = crypto_alloc_hash("michael_mic", 0, CRYPTO_ALG_ASYNC); if (IS_ERR(priv->tx_tfm_michael)) { printk(KERN_DEBUG "ieee80211_crypt_tkip: could not allocate " "crypto API michael_mic\n"); priv->tx_tfm_michael = NULL; goto fail; } priv->rx_tfm_arc4 = crypto_alloc_blkcipher("ecb(arc4)", 0, CRYPTO_ALG_ASYNC); if (IS_ERR(priv->rx_tfm_arc4)) { printk(KERN_DEBUG "ieee80211_crypt_tkip: could not allocate " "crypto API arc4\n"); priv->rx_tfm_arc4 = NULL; goto fail; } priv->rx_tfm_michael = crypto_alloc_hash("michael_mic", 0, CRYPTO_ALG_ASYNC); if (IS_ERR(priv->rx_tfm_michael)) { printk(KERN_DEBUG "ieee80211_crypt_tkip: could not allocate " "crypto API michael_mic\n"); priv->rx_tfm_michael = NULL; goto fail; } return priv; fail: if (priv) { if (priv->tx_tfm_michael) crypto_free_hash(priv->tx_tfm_michael); if (priv->tx_tfm_arc4) crypto_free_blkcipher(priv->tx_tfm_arc4); if (priv->rx_tfm_michael) crypto_free_hash(priv->rx_tfm_michael); if (priv->rx_tfm_arc4) crypto_free_blkcipher(priv->rx_tfm_arc4); kfree(priv); } return NULL; } static void ieee80211_tkip_deinit(void *priv) { struct ieee80211_tkip_data *_priv = priv; if (_priv) { if (_priv->tx_tfm_michael) crypto_free_hash(_priv->tx_tfm_michael); if (_priv->tx_tfm_arc4) crypto_free_blkcipher(_priv->tx_tfm_arc4); if (_priv->rx_tfm_michael) crypto_free_hash(_priv->rx_tfm_michael); if (_priv->rx_tfm_arc4) crypto_free_blkcipher(_priv->rx_tfm_arc4); } kfree(priv); } static inline u16 RotR1(u16 val) { return (val >> 1) | (val << 15); } static inline u8 Lo8(u16 val) { return val & 0xff; } static inline u8 Hi8(u16 val) { return val >> 8; } static inline u16 Lo16(u32 val) { return val & 0xffff; } static inline u16 Hi16(u32 val) { return val >> 16; } static inline u16 Mk16(u8 hi, u8 lo) { return lo | (((u16) hi) << 8); } static inline u16 Mk16_le(__le16 * v) { return le16_to_cpu(*v); } static const u16 Sbox[256] = { 0xC6A5, 0xF884, 0xEE99, 0xF68D, 0xFF0D, 0xD6BD, 0xDEB1, 0x9154, 0x6050, 0x0203, 0xCEA9, 0x567D, 0xE719, 0xB562, 0x4DE6, 0xEC9A, 0x8F45, 0x1F9D, 0x8940, 0xFA87, 0xEF15, 0xB2EB, 0x8EC9, 0xFB0B, 0x41EC, 0xB367, 0x5FFD, 0x45EA, 0x23BF, 0x53F7, 0xE496, 0x9B5B, 0x75C2, 0xE11C, 0x3DAE, 0x4C6A, 0x6C5A, 0x7E41, 0xF502, 0x834F, 0x685C, 0x51F4, 0xD134, 0xF908, 0xE293, 0xAB73, 0x6253, 0x2A3F, 0x080C, 0x9552, 0x4665, 0x9D5E, 0x3028, 0x37A1, 0x0A0F, 0x2FB5, 0x0E09, 0x2436, 0x1B9B, 0xDF3D, 0xCD26, 0x4E69, 0x7FCD, 0xEA9F, 0x121B, 0x1D9E, 0x5874, 0x342E, 0x362D, 0xDCB2, 0xB4EE, 0x5BFB, 0xA4F6, 0x764D, 0xB761, 0x7DCE, 0x527B, 0xDD3E, 0x5E71, 0x1397, 0xA6F5, 0xB968, 0x0000, 0xC12C, 0x4060, 0xE31F, 0x79C8, 0xB6ED, 0xD4BE, 0x8D46, 0x67D9, 0x724B, 0x94DE, 0x98D4, 0xB0E8, 0x854A, 0xBB6B, 0xC52A, 0x4FE5, 0xED16, 0x86C5, 0x9AD7, 0x6655, 0x1194, 0x8ACF, 0xE910, 0x0406, 0xFE81, 0xA0F0, 0x7844, 0x25BA, 0x4BE3, 0xA2F3, 0x5DFE, 0x80C0, 0x058A, 0x3FAD, 0x21BC, 0x7048, 0xF104, 0x63DF, 0x77C1, 0xAF75, 0x4263, 0x2030, 0xE51A, 0xFD0E, 0xBF6D, 0x814C, 0x1814, 0x2635, 0xC32F, 0xBEE1, 0x35A2, 0x88CC, 0x2E39, 0x9357, 0x55F2, 0xFC82, 0x7A47, 0xC8AC, 0xBAE7, 0x322B, 0xE695, 0xC0A0, 0x1998, 0x9ED1, 0xA37F, 0x4466, 0x547E, 0x3BAB, 0x0B83, 0x8CCA, 0xC729, 0x6BD3, 0x283C, 0xA779, 0xBCE2, 0x161D, 0xAD76, 0xDB3B, 0x6456, 0x744E, 0x141E, 0x92DB, 0x0C0A, 0x486C, 0xB8E4, 0x9F5D, 0xBD6E, 0x43EF, 0xC4A6, 0x39A8, 0x31A4, 0xD337, 0xF28B, 0xD532, 0x8B43, 0x6E59, 0xDAB7, 0x018C, 0xB164, 0x9CD2, 0x49E0, 0xD8B4, 0xACFA, 0xF307, 0xCF25, 0xCAAF, 0xF48E, 0x47E9, 0x1018, 0x6FD5, 0xF088, 0x4A6F, 0x5C72, 0x3824, 0x57F1, 0x73C7, 0x9751, 0xCB23, 0xA17C, 0xE89C, 0x3E21, 0x96DD, 0x61DC, 0x0D86, 0x0F85, 0xE090, 0x7C42, 0x71C4, 0xCCAA, 0x90D8, 0x0605, 0xF701, 0x1C12, 0xC2A3, 0x6A5F, 0xAEF9, 0x69D0, 0x1791, 0x9958, 0x3A27, 0x27B9, 0xD938, 0xEB13, 0x2BB3, 0x2233, 0xD2BB, 0xA970, 0x0789, 0x33A7, 0x2DB6, 0x3C22, 0x1592, 0xC920, 0x8749, 0xAAFF, 0x5078, 0xA57A, 0x038F, 0x59F8, 0x0980, 0x1A17, 0x65DA, 0xD731, 0x84C6, 0xD0B8, 0x82C3, 0x29B0, 0x5A77, 0x1E11, 0x7BCB, 0xA8FC, 0x6DD6, 0x2C3A, }; static inline u16 _S_(u16 v) { u16 t = Sbox[Hi8(v)]; return Sbox[Lo8(v)] ^ ((t << 8) | (t >> 8)); } #define PHASE1_LOOP_COUNT 8 static void tkip_mixing_phase1(u16 * TTAK, const u8 * TK, const u8 * TA, u32 IV32) { int i, j; /* Initialize the 80-bit TTAK from TSC (IV32) and TA[0..5] */ TTAK[0] = Lo16(IV32); TTAK[1] = Hi16(IV32); TTAK[2] = Mk16(TA[1], TA[0]); TTAK[3] = Mk16(TA[3], TA[2]); TTAK[4] = Mk16(TA[5], TA[4]); for (i = 0; i < PHASE1_LOOP_COUNT; i++) { j = 2 * (i & 1); TTAK[0] += _S_(TTAK[4] ^ Mk16(TK[1 + j], TK[0 + j])); TTAK[1] += _S_(TTAK[0] ^ Mk16(TK[5 + j], TK[4 + j])); TTAK[2] += _S_(TTAK[1] ^ Mk16(TK[9 + j], TK[8 + j])); TTAK[3] += _S_(TTAK[2] ^ Mk16(TK[13 + j], TK[12 + j])); TTAK[4] += _S_(TTAK[3] ^ Mk16(TK[1 + j], TK[0 + j])) + i; } } static void tkip_mixing_phase2(u8 * WEPSeed, const u8 * TK, const u16 * TTAK, u16 IV16) { /* Make temporary area overlap WEP seed so that the final copy can be * avoided on little endian hosts. */ u16 *PPK = (u16 *) & WEPSeed[4]; /* Step 1 - make copy of TTAK and bring in TSC */ PPK[0] = TTAK[0]; PPK[1] = TTAK[1]; PPK[2] = TTAK[2]; PPK[3] = TTAK[3]; PPK[4] = TTAK[4]; PPK[5] = TTAK[4] + IV16; /* Step 2 - 96-bit bijective mixing using S-box */ PPK[0] += _S_(PPK[5] ^ Mk16_le((__le16 *) & TK[0])); PPK[1] += _S_(PPK[0] ^ Mk16_le((__le16 *) & TK[2])); PPK[2] += _S_(PPK[1] ^ Mk16_le((__le16 *) & TK[4])); PPK[3] += _S_(PPK[2] ^ Mk16_le((__le16 *) & TK[6])); PPK[4] += _S_(PPK[3] ^ Mk16_le((__le16 *) & TK[8])); PPK[5] += _S_(PPK[4] ^ Mk16_le((__le16 *) & TK[10])); PPK[0] += RotR1(PPK[5] ^ Mk16_le((__le16 *) & TK[12])); PPK[1] += RotR1(PPK[0] ^ Mk16_le((__le16 *) & TK[14])); PPK[2] += RotR1(PPK[1]); PPK[3] += RotR1(PPK[2]); PPK[4] += RotR1(PPK[3]); PPK[5] += RotR1(PPK[4]); /* Step 3 - bring in last of TK bits, assign 24-bit WEP IV value * WEPSeed[0..2] is transmitted as WEP IV */ WEPSeed[0] = Hi8(IV16); WEPSeed[1] = (Hi8(IV16) | 0x20) & 0x7F; WEPSeed[2] = Lo8(IV16); WEPSeed[3] = Lo8((PPK[5] ^ Mk16_le((__le16 *) & TK[0])) >> 1); #ifdef __BIG_ENDIAN { int i; for (i = 0; i < 6; i++) PPK[i] = (PPK[i] << 8) | (PPK[i] >> 8); } #endif } static int ieee80211_tkip_hdr(struct sk_buff *skb, int hdr_len, u8 * rc4key, int keylen, void *priv) { struct ieee80211_tkip_data *tkey = priv; int len; u8 *pos; struct ieee80211_hdr_4addr *hdr; hdr = (struct ieee80211_hdr_4addr *)skb->data; if (skb_headroom(skb) < 8 || skb->len < hdr_len) return -1; if (rc4key == NULL || keylen < 16) return -1; if (!tkey->tx_phase1_done) { tkip_mixing_phase1(tkey->tx_ttak, tkey->key, hdr->addr2, tkey->tx_iv32); tkey->tx_phase1_done = 1; } tkip_mixing_phase2(rc4key, tkey->key, tkey->tx_ttak, tkey->tx_iv16); len = skb->len - hdr_len; pos = skb_push(skb, 8); memmove(pos, pos + 8, hdr_len); pos += hdr_len; *pos++ = *rc4key; *pos++ = *(rc4key + 1); *pos++ = *(rc4key + 2); *pos++ = (tkey->key_idx << 6) | (1 << 5) /* Ext IV included */ ; *pos++ = tkey->tx_iv32 & 0xff; *pos++ = (tkey->tx_iv32 >> 8) & 0xff; *pos++ = (tkey->tx_iv32 >> 16) & 0xff; *pos++ = (tkey->tx_iv32 >> 24) & 0xff; tkey->tx_iv16++; if (tkey->tx_iv16 == 0) { tkey->tx_phase1_done = 0; tkey->tx_iv32++; } return 8; } static int ieee80211_tkip_encrypt(struct sk_buff *skb, int hdr_len, void *priv) { struct ieee80211_tkip_data *tkey = priv; struct blkcipher_desc desc = { .tfm = tkey->tx_tfm_arc4 }; int len; u8 rc4key[16], *pos, *icv; u32 crc; struct scatterlist sg; DECLARE_MAC_BUF(mac); if (tkey->flags & IEEE80211_CRYPTO_TKIP_COUNTERMEASURES) { if (net_ratelimit()) { struct ieee80211_hdr_4addr *hdr = (struct ieee80211_hdr_4addr *)skb->data; printk(KERN_DEBUG ": TKIP countermeasures: dropped " "TX packet to %s\n", print_mac(mac, hdr->addr1)); } return -1; } if (skb_tailroom(skb) < 4 || skb->len < hdr_len) return -1; len = skb->len - hdr_len; pos = skb->data + hdr_len; if ((ieee80211_tkip_hdr(skb, hdr_len, rc4key, 16, priv)) < 0) return -1; icv = skb_put(skb, 4); crc = ~crc32_le(~0, pos, len); icv[0] = crc; icv[1] = crc >> 8; icv[2] = crc >> 16; icv[3] = crc >> 24; crypto_blkcipher_setkey(tkey->tx_tfm_arc4, rc4key, 16); sg_init_one(&sg, pos, len + 4); return crypto_blkcipher_encrypt(&desc, &sg, &sg, len + 4); } /* * deal with seq counter wrapping correctly. * refer to timer_after() for jiffies wrapping handling */ static inline int tkip_replay_check(u32 iv32_n, u16 iv16_n, u32 iv32_o, u16 iv16_o) { if ((s32)iv32_n - (s32)iv32_o < 0 || (iv32_n == iv32_o && iv16_n <= iv16_o)) return 1; return 0; } static int ieee80211_tkip_decrypt(struct sk_buff *skb, int hdr_len, void *priv) { struct ieee80211_tkip_data *tkey = priv; struct blkcipher_desc desc = { .tfm = tkey->rx_tfm_arc4 }; u8 rc4key[16]; u8 keyidx, *pos; u32 iv32; u16 iv16; struct ieee80211_hdr_4addr *hdr; u8 icv[4]; u32 crc; struct scatterlist sg; int plen; DECLARE_MAC_BUF(mac); hdr = (struct ieee80211_hdr_4addr *)skb->data; if (tkey->flags & IEEE80211_CRYPTO_TKIP_COUNTERMEASURES) { if (net_ratelimit()) { printk(KERN_DEBUG ": TKIP countermeasures: dropped " "received packet from %s\n", print_mac(mac, hdr->addr2)); } return -1; } if (skb->len < hdr_len + 8 + 4) return -1; pos = skb->data + hdr_len; keyidx = pos[3]; if (!(keyidx & (1 << 5))) { if (net_ratelimit()) { printk(KERN_DEBUG "TKIP: received packet without ExtIV" " flag from %s\n", print_mac(mac, hdr->addr2)); } return -2; } keyidx >>= 6; if (tkey->key_idx != keyidx) { printk(KERN_DEBUG "TKIP: RX tkey->key_idx=%d frame " "keyidx=%d priv=%p\n", tkey->key_idx, keyidx, priv); return -6; } if (!tkey->key_set) { if (net_ratelimit()) { printk(KERN_DEBUG "TKIP: received packet from %s" " with keyid=%d that does not have a configured" " key\n", print_mac(mac, hdr->addr2), keyidx); } return -3; } iv16 = (pos[0] << 8) | pos[2]; iv32 = pos[4] | (pos[5] << 8) | (pos[6] << 16) | (pos[7] << 24); pos += 8; if (tkip_replay_check(iv32, iv16, tkey->rx_iv32, tkey->rx_iv16)) { if (ieee80211_ratelimit_debug(IEEE80211_DL_DROP)) { IEEE80211_DEBUG_DROP("TKIP: replay detected: STA=%s" " previous TSC %08x%04x received TSC " "%08x%04x\n", print_mac(mac, hdr->addr2), tkey->rx_iv32, tkey->rx_iv16, iv32, iv16); } tkey->dot11RSNAStatsTKIPReplays++; return -4; } if (iv32 != tkey->rx_iv32 || !tkey->rx_phase1_done) { tkip_mixing_phase1(tkey->rx_ttak, tkey->key, hdr->addr2, iv32); tkey->rx_phase1_done = 1; } tkip_mixing_phase2(rc4key, tkey->key, tkey->rx_ttak, iv16); plen = skb->len - hdr_len - 12; crypto_blkcipher_setkey(tkey->rx_tfm_arc4, rc4key, 16); sg_init_one(&sg, pos, plen + 4); if (crypto_blkcipher_decrypt(&desc, &sg, &sg, plen + 4)) { if (net_ratelimit()) { printk(KERN_DEBUG ": TKIP: failed to decrypt " "received packet from %s\n", print_mac(mac, hdr->addr2)); } return -7; } crc = ~crc32_le(~0, pos, plen); icv[0] = crc; icv[1] = crc >> 8; icv[2] = crc >> 16; icv[3] = crc >> 24; if (memcmp(icv, pos + plen, 4) != 0) { if (iv32 != tkey->rx_iv32) { /* Previously cached Phase1 result was already lost, so * it needs to be recalculated for the next packet. */ tkey->rx_phase1_done = 0; } if (ieee80211_ratelimit_debug(IEEE80211_DL_DROP)) { IEEE80211_DEBUG_DROP("TKIP: ICV error detected: STA=" "%s\n", print_mac(mac, hdr->addr2)); } tkey->dot11RSNAStatsTKIPICVErrors++; return -5; } /* Update real counters only after Michael MIC verification has * completed */ tkey->rx_iv32_new = iv32; tkey->rx_iv16_new = iv16; /* Remove IV and ICV */ memmove(skb->data + 8, skb->data, hdr_len); skb_pull(skb, 8); skb_trim(skb, skb->len - 4); return keyidx; } static int michael_mic(struct crypto_hash *tfm_michael, u8 * key, u8 * hdr, u8 * data, size_t data_len, u8 * mic) { struct hash_desc desc; struct scatterlist sg[2]; if (tfm_michael == NULL) { printk(KERN_WARNING "michael_mic: tfm_michael == NULL\n"); return -1; } sg_init_table(sg, 2); sg_set_buf(&sg[0], hdr, 16); sg_set_buf(&sg[1], data, data_len); if (crypto_hash_setkey(tfm_michael, key, 8)) return -1; desc.tfm = tfm_michael; desc.flags = 0; return crypto_hash_digest(&desc, sg, data_len + 16, mic); } static void michael_mic_hdr(struct sk_buff *skb, u8 * hdr) { struct ieee80211_hdr_4addr *hdr11; u16 stype; hdr11 = (struct ieee80211_hdr_4addr *)skb->data; stype = WLAN_FC_GET_STYPE(le16_to_cpu(hdr11->frame_ctl)); switch (le16_to_cpu(hdr11->frame_ctl) & (IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS)) { case IEEE80211_FCTL_TODS: memcpy(hdr, hdr11->addr3, ETH_ALEN); /* DA */ memcpy(hdr + ETH_ALEN, hdr11->addr2, ETH_ALEN); /* SA */ break; case IEEE80211_FCTL_FROMDS: memcpy(hdr, hdr11->addr1, ETH_ALEN); /* DA */ memcpy(hdr + ETH_ALEN, hdr11->addr3, ETH_ALEN); /* SA */ break; case IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS: memcpy(hdr, hdr11->addr3, ETH_ALEN); /* DA */ memcpy(hdr + ETH_ALEN, hdr11->addr4, ETH_ALEN); /* SA */ break; case 0: memcpy(hdr, hdr11->addr1, ETH_ALEN); /* DA */ memcpy(hdr + ETH_ALEN, hdr11->addr2, ETH_ALEN); /* SA */ break; } if (stype & IEEE80211_STYPE_QOS_DATA) { const struct ieee80211_hdr_3addrqos *qoshdr = (struct ieee80211_hdr_3addrqos *)skb->data; hdr[12] = le16_to_cpu(qoshdr->qos_ctl) & IEEE80211_QCTL_TID; } else hdr[12] = 0; /* priority */ hdr[13] = hdr[14] = hdr[15] = 0; /* reserved */ } static int ieee80211_michael_mic_add(struct sk_buff *skb, int hdr_len, void *priv) { struct ieee80211_tkip_data *tkey = priv; u8 *pos; if (skb_tailroom(skb) < 8 || skb->len < hdr_len) { printk(KERN_DEBUG "Invalid packet for Michael MIC add " "(tailroom=%d hdr_len=%d skb->len=%d)\n", skb_tailroom(skb), hdr_len, skb->len); return -1; } michael_mic_hdr(skb, tkey->tx_hdr); pos = skb_put(skb, 8); if (michael_mic(tkey->tx_tfm_michael, &tkey->key[16], tkey->tx_hdr, skb->data + hdr_len, skb->len - 8 - hdr_len, pos)) return -1; return 0; } static void ieee80211_michael_mic_failure(struct net_device *dev, struct ieee80211_hdr_4addr *hdr, int keyidx) { union iwreq_data wrqu; struct iw_michaelmicfailure ev; /* TODO: needed parameters: count, keyid, key type, TSC */ memset(&ev, 0, sizeof(ev)); ev.flags = keyidx & IW_MICFAILURE_KEY_ID; if (hdr->addr1[0] & 0x01) ev.flags |= IW_MICFAILURE_GROUP; else ev.flags |= IW_MICFAILURE_PAIRWISE; ev.src_addr.sa_family = ARPHRD_ETHER; memcpy(ev.src_addr.sa_data, hdr->addr2, ETH_ALEN); memset(&wrqu, 0, sizeof(wrqu)); wrqu.data.length = sizeof(ev); wireless_send_event(dev, IWEVMICHAELMICFAILURE, &wrqu, (char *)&ev); } static int ieee80211_michael_mic_verify(struct sk_buff *skb, int keyidx, int hdr_len, void *priv) { struct ieee80211_tkip_data *tkey = priv; u8 mic[8]; DECLARE_MAC_BUF(mac); if (!tkey->key_set) return -1; michael_mic_hdr(skb, tkey->rx_hdr); if (michael_mic(tkey->rx_tfm_michael, &tkey->key[24], tkey->rx_hdr, skb->data + hdr_len, skb->len - 8 - hdr_len, mic)) return -1; if (memcmp(mic, skb->data + skb->len - 8, 8) != 0) { struct ieee80211_hdr_4addr *hdr; hdr = (struct ieee80211_hdr_4addr *)skb->data; printk(KERN_DEBUG "%s: Michael MIC verification failed for " "MSDU from %s keyidx=%d\n", skb->dev ? skb->dev->name : "N/A", print_mac(mac, hdr->addr2), keyidx); if (skb->dev) ieee80211_michael_mic_failure(skb->dev, hdr, keyidx); tkey->dot11RSNAStatsTKIPLocalMICFailures++; return -1; } /* Update TSC counters for RX now that the packet verification has * completed. */ tkey->rx_iv32 = tkey->rx_iv32_new; tkey->rx_iv16 = tkey->rx_iv16_new; skb_trim(skb, skb->len - 8); return 0; } static int ieee80211_tkip_set_key(void *key, int len, u8 * seq, void *priv) { struct ieee80211_tkip_data *tkey = priv; int keyidx; struct crypto_hash *tfm = tkey->tx_tfm_michael; struct crypto_blkcipher *tfm2 = tkey->tx_tfm_arc4; struct crypto_hash *tfm3 = tkey->rx_tfm_michael; struct crypto_blkcipher *tfm4 = tkey->rx_tfm_arc4; keyidx = tkey->key_idx; memset(tkey, 0, sizeof(*tkey)); tkey->key_idx = keyidx; tkey->tx_tfm_michael = tfm; tkey->tx_tfm_arc4 = tfm2; tkey->rx_tfm_michael = tfm3; tkey->rx_tfm_arc4 = tfm4; if (len == TKIP_KEY_LEN) { memcpy(tkey->key, key, TKIP_KEY_LEN); tkey->key_set = 1; tkey->tx_iv16 = 1; /* TSC is initialized to 1 */ if (seq) { tkey->rx_iv32 = (seq[5] << 24) | (seq[4] << 16) | (seq[3] << 8) | seq[2]; tkey->rx_iv16 = (seq[1] << 8) | seq[0]; } } else if (len == 0) tkey->key_set = 0; else return -1; return 0; } static int ieee80211_tkip_get_key(void *key, int len, u8 * seq, void *priv) { struct ieee80211_tkip_data *tkey = priv; if (len < TKIP_KEY_LEN) return -1; if (!tkey->key_set) return 0; memcpy(key, tkey->key, TKIP_KEY_LEN); if (seq) { /* Return the sequence number of the last transmitted frame. */ u16 iv16 = tkey->tx_iv16; u32 iv32 = tkey->tx_iv32; if (iv16 == 0) iv32--; iv16--; seq[0] = tkey->tx_iv16; seq[1] = tkey->tx_iv16 >> 8; seq[2] = tkey->tx_iv32; seq[3] = tkey->tx_iv32 >> 8; seq[4] = tkey->tx_iv32 >> 16; seq[5] = tkey->tx_iv32 >> 24; } return TKIP_KEY_LEN; } static char *ieee80211_tkip_print_stats(char *p, void *priv) { struct ieee80211_tkip_data *tkip = priv; p += sprintf(p, "key[%d] alg=TKIP key_set=%d " "tx_pn=%02x%02x%02x%02x%02x%02x " "rx_pn=%02x%02x%02x%02x%02x%02x " "replays=%d icv_errors=%d local_mic_failures=%d\n", tkip->key_idx, tkip->key_set, (tkip->tx_iv32 >> 24) & 0xff, (tkip->tx_iv32 >> 16) & 0xff, (tkip->tx_iv32 >> 8) & 0xff, tkip->tx_iv32 & 0xff, (tkip->tx_iv16 >> 8) & 0xff, tkip->tx_iv16 & 0xff, (tkip->rx_iv32 >> 24) & 0xff, (tkip->rx_iv32 >> 16) & 0xff, (tkip->rx_iv32 >> 8) & 0xff, tkip->rx_iv32 & 0xff, (tkip->rx_iv16 >> 8) & 0xff, tkip->rx_iv16 & 0xff, tkip->dot11RSNAStatsTKIPReplays, tkip->dot11RSNAStatsTKIPICVErrors, tkip->dot11RSNAStatsTKIPLocalMICFailures); return p; } static struct ieee80211_crypto_ops ieee80211_crypt_tkip = { .name = "TKIP", .init = ieee80211_tkip_init, .deinit = ieee80211_tkip_deinit, .build_iv = ieee80211_tkip_hdr, .encrypt_mpdu = ieee80211_tkip_encrypt, .decrypt_mpdu = ieee80211_tkip_decrypt, .encrypt_msdu = ieee80211_michael_mic_add, .decrypt_msdu = ieee80211_michael_mic_verify, .set_key = ieee80211_tkip_set_key, .get_key = ieee80211_tkip_get_key, .print_stats = ieee80211_tkip_print_stats, .extra_mpdu_prefix_len = 4 + 4, /* IV + ExtIV */ .extra_mpdu_postfix_len = 4, /* ICV */ .extra_msdu_postfix_len = 8, /* MIC */ .get_flags = ieee80211_tkip_get_flags, .set_flags = ieee80211_tkip_set_flags, .owner = THIS_MODULE, }; static int __init ieee80211_crypto_tkip_init(void) { return ieee80211_register_crypto_ops(&ieee80211_crypt_tkip); } static void __exit ieee80211_crypto_tkip_exit(void) { ieee80211_unregister_crypto_ops(&ieee80211_crypt_tkip); } module_init(ieee80211_crypto_tkip_init); module_exit(ieee80211_crypto_tkip_exit);