diff options
author | Linus Torvalds <torvalds@evo.osdl.org> | 2005-09-02 00:48:33 -0700 |
---|---|---|
committer | Linus Torvalds <torvalds@evo.osdl.org> | 2005-09-02 00:48:33 -0700 |
commit | 5d8c397f304e1363f8ff9749b08172eb59e6534a (patch) | |
tree | 57ff502553918aa7309b7375e983f27f719e7b28 /net/ieee80211/ieee80211_crypt_tkip.c | |
parent | 44757223cd77f6e332dfa0b043c67df7b665bc19 (diff) | |
parent | ceeec3dc375e3b0618f16b34efc56fe093918f8b (diff) |
Merge refs/heads/ieee80211-wifi from master.kernel.org:/pub/scm/linux/kernel/git/jgarzik/netdev-2.6
Diffstat (limited to 'net/ieee80211/ieee80211_crypt_tkip.c')
-rw-r--r-- | net/ieee80211/ieee80211_crypt_tkip.c | 708 |
1 files changed, 708 insertions, 0 deletions
diff --git a/net/ieee80211/ieee80211_crypt_tkip.c b/net/ieee80211/ieee80211_crypt_tkip.c new file mode 100644 index 00000000000..f91d92c6df2 --- /dev/null +++ b/net/ieee80211/ieee80211_crypt_tkip.c @@ -0,0 +1,708 @@ +/* + * Host AP crypt: host-based TKIP encryption implementation for Host AP driver + * + * Copyright (c) 2003-2004, Jouni Malinen <jkmaline@cc.hut.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/config.h> +#include <linux/version.h> +#include <linux/module.h> +#include <linux/init.h> +#include <linux/slab.h> +#include <linux/random.h> +#include <linux/skbuff.h> +#include <linux/netdevice.h> +#include <linux/if_ether.h> +#include <linux/if_arp.h> +#include <asm/string.h> + +#include <net/ieee80211.h> + + +#include <linux/crypto.h> +#include <asm/scatterlist.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_tfm *tfm_arc4; + struct crypto_tfm *tfm_michael; + + /* scratch buffers for virt_to_page() (crypto API) */ + u8 rx_hdr[16], tx_hdr[16]; +}; + +static void * ieee80211_tkip_init(int key_idx) +{ + struct ieee80211_tkip_data *priv; + + priv = kmalloc(sizeof(*priv), GFP_ATOMIC); + if (priv == NULL) + goto fail; + memset(priv, 0, sizeof(*priv)); + priv->key_idx = key_idx; + + priv->tfm_arc4 = crypto_alloc_tfm("arc4", 0); + if (priv->tfm_arc4 == NULL) { + printk(KERN_DEBUG "ieee80211_crypt_tkip: could not allocate " + "crypto API arc4\n"); + goto fail; + } + + priv->tfm_michael = crypto_alloc_tfm("michael_mic", 0); + if (priv->tfm_michael == NULL) { + printk(KERN_DEBUG "ieee80211_crypt_tkip: could not allocate " + "crypto API michael_mic\n"); + goto fail; + } + + return priv; + +fail: + if (priv) { + if (priv->tfm_michael) + crypto_free_tfm(priv->tfm_michael); + if (priv->tfm_arc4) + crypto_free_tfm(priv->tfm_arc4); + kfree(priv); + } + + return NULL; +} + + +static void ieee80211_tkip_deinit(void *priv) +{ + struct ieee80211_tkip_data *_priv = priv; + if (_priv && _priv->tfm_michael) + crypto_free_tfm(_priv->tfm_michael); + if (_priv && _priv->tfm_arc4) + crypto_free_tfm(_priv->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(u16 *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((u16 *) &TK[0])); + PPK[1] += _S_(PPK[0] ^ Mk16_le((u16 *) &TK[2])); + PPK[2] += _S_(PPK[1] ^ Mk16_le((u16 *) &TK[4])); + PPK[3] += _S_(PPK[2] ^ Mk16_le((u16 *) &TK[6])); + PPK[4] += _S_(PPK[3] ^ Mk16_le((u16 *) &TK[8])); + PPK[5] += _S_(PPK[4] ^ Mk16_le((u16 *) &TK[10])); + + PPK[0] += RotR1(PPK[5] ^ Mk16_le((u16 *) &TK[12])); + PPK[1] += RotR1(PPK[0] ^ Mk16_le((u16 *) &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((u16 *) &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_encrypt(struct sk_buff *skb, int hdr_len, void *priv) +{ + struct ieee80211_tkip_data *tkey = priv; + int len; + u8 rc4key[16], *pos, *icv; + struct ieee80211_hdr *hdr; + u32 crc; + struct scatterlist sg; + + if (skb_headroom(skb) < 8 || skb_tailroom(skb) < 4 || + skb->len < hdr_len) + return -1; + + hdr = (struct ieee80211_hdr *) skb->data; + 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; + icv = skb_put(skb, 4); + + *pos++ = rc4key[0]; + *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; + + crc = ~crc32_le(~0, pos, len); + icv[0] = crc; + icv[1] = crc >> 8; + icv[2] = crc >> 16; + icv[3] = crc >> 24; + + crypto_cipher_setkey(tkey->tfm_arc4, rc4key, 16); + sg.page = virt_to_page(pos); + sg.offset = offset_in_page(pos); + sg.length = len + 4; + crypto_cipher_encrypt(tkey->tfm_arc4, &sg, &sg, len + 4); + + tkey->tx_iv16++; + if (tkey->tx_iv16 == 0) { + tkey->tx_phase1_done = 0; + tkey->tx_iv32++; + } + + return 0; +} + +static int ieee80211_tkip_decrypt(struct sk_buff *skb, int hdr_len, void *priv) +{ + struct ieee80211_tkip_data *tkey = priv; + u8 rc4key[16]; + u8 keyidx, *pos; + u32 iv32; + u16 iv16; + struct ieee80211_hdr *hdr; + u8 icv[4]; + u32 crc; + struct scatterlist sg; + int plen; + + if (skb->len < hdr_len + 8 + 4) + return -1; + + hdr = (struct ieee80211_hdr *) skb->data; + 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 " MAC_FMT "\n", MAC_ARG(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 " MAC_FMT + " with keyid=%d that does not have a configured" + " key\n", MAC_ARG(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 (iv32 < tkey->rx_iv32 || + (iv32 == tkey->rx_iv32 && iv16 <= tkey->rx_iv16)) { + if (net_ratelimit()) { + printk(KERN_DEBUG "TKIP: replay detected: STA=" MAC_FMT + " previous TSC %08x%04x received TSC " + "%08x%04x\n", MAC_ARG(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_cipher_setkey(tkey->tfm_arc4, rc4key, 16); + sg.page = virt_to_page(pos); + sg.offset = offset_in_page(pos); + sg.length = plen + 4; + crypto_cipher_decrypt(tkey->tfm_arc4, &sg, &sg, plen + 4); + + 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 (net_ratelimit()) { + printk(KERN_DEBUG "TKIP: ICV error detected: STA=" + MAC_FMT "\n", MAC_ARG(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 ieee80211_tkip_data *tkey, u8 *key, u8 *hdr, + u8 *data, size_t data_len, u8 *mic) +{ + struct scatterlist sg[2]; + + if (tkey->tfm_michael == NULL) { + printk(KERN_WARNING "michael_mic: tfm_michael == NULL\n"); + return -1; + } + sg[0].page = virt_to_page(hdr); + sg[0].offset = offset_in_page(hdr); + sg[0].length = 16; + + sg[1].page = virt_to_page(data); + sg[1].offset = offset_in_page(data); + sg[1].length = data_len; + + crypto_digest_init(tkey->tfm_michael); + crypto_digest_setkey(tkey->tfm_michael, key, 8); + crypto_digest_update(tkey->tfm_michael, sg, 2); + crypto_digest_final(tkey->tfm_michael, mic); + + return 0; +} + +static void michael_mic_hdr(struct sk_buff *skb, u8 *hdr) +{ + struct ieee80211_hdr *hdr11; + + hdr11 = (struct ieee80211_hdr *) skb->data; + 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; + } + + 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, &tkey->key[16], tkey->tx_hdr, + skb->data + hdr_len, skb->len - 8 - hdr_len, pos)) + return -1; + + return 0; +} + + +#if WIRELESS_EXT >= 18 +static void ieee80211_michael_mic_failure(struct net_device *dev, + struct ieee80211_hdr *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); +} +#elif WIRELESS_EXT >= 15 +static void ieee80211_michael_mic_failure(struct net_device *dev, + struct ieee80211_hdr *hdr, + int keyidx) +{ + union iwreq_data wrqu; + char buf[128]; + + /* TODO: needed parameters: count, keyid, key type, TSC */ + sprintf(buf, "MLME-MICHAELMICFAILURE.indication(keyid=%d %scast addr=" + MAC_FMT ")", keyidx, hdr->addr1[0] & 0x01 ? "broad" : "uni", + MAC_ARG(hdr->addr2)); + memset(&wrqu, 0, sizeof(wrqu)); + wrqu.data.length = strlen(buf); + wireless_send_event(dev, IWEVCUSTOM, &wrqu, buf); +} +#else /* WIRELESS_EXT >= 15 */ +static inline void ieee80211_michael_mic_failure(struct net_device *dev, + struct ieee80211_hdr *hdr, + int keyidx) +{ +} +#endif /* WIRELESS_EXT >= 15 */ + + +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]; + + if (!tkey->key_set) + return -1; + + michael_mic_hdr(skb, tkey->rx_hdr); + if (michael_mic(tkey, &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 *hdr; + hdr = (struct ieee80211_hdr *) skb->data; + printk(KERN_DEBUG "%s: Michael MIC verification failed for " + "MSDU from " MAC_FMT " keyidx=%d\n", + skb->dev ? skb->dev->name : "N/A", MAC_ARG(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_tfm *tfm = tkey->tfm_michael; + struct crypto_tfm *tfm2 = tkey->tfm_arc4; + + keyidx = tkey->key_idx; + memset(tkey, 0, sizeof(*tkey)); + tkey->key_idx = keyidx; + tkey->tfm_michael = tfm; + tkey->tfm_arc4 = tfm2; + 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, + .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_prefix_len = 4 + 4, /* IV + ExtIV */ + .extra_postfix_len = 8 + 4, /* MIC + ICV */ + .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); |