diff options
Diffstat (limited to 'net/mac80211/tkip.c')
-rw-r--r-- | net/mac80211/tkip.c | 282 |
1 files changed, 106 insertions, 176 deletions
diff --git a/net/mac80211/tkip.c b/net/mac80211/tkip.c index 09093da24af..995f7af3d25 100644 --- a/net/mac80211/tkip.c +++ b/net/mac80211/tkip.c @@ -6,25 +6,23 @@ * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. */ - #include <linux/kernel.h> +#include <linux/bitops.h> #include <linux/types.h> #include <linux/netdevice.h> +#include <asm/unaligned.h> #include <net/mac80211.h> #include "key.h" #include "tkip.h" #include "wep.h" - -/* TKIP key mixing functions */ - - #define PHASE1_LOOP_COUNT 8 - -/* 2-byte by 2-byte subset of the full AES S-box table; second part of this - * table is identical to first part but byte-swapped */ +/* + * 2-byte by 2-byte subset of the full AES S-box table; second part of this + * table is identical to first part but byte-swapped + */ static const u16 tkip_sbox[256] = { 0xC6A5, 0xF884, 0xEE99, 0xF68D, 0xFF0D, 0xD6BD, 0xDEB1, 0x9154, @@ -61,84 +59,54 @@ static const u16 tkip_sbox[256] = 0x82C3, 0x29B0, 0x5A77, 0x1E11, 0x7BCB, 0xA8FC, 0x6DD6, 0x2C3A, }; - -static inline u16 Mk16(u8 x, u8 y) +static u16 tkipS(u16 val) { - return ((u16) x << 8) | (u16) y; + return tkip_sbox[val & 0xff] ^ swab16(tkip_sbox[val >> 8]); } - -static inline u8 Hi8(u16 v) -{ - return v >> 8; -} - - -static inline u8 Lo8(u16 v) -{ - return v & 0xff; -} - - -static inline u16 Hi16(u32 v) -{ - return v >> 16; -} - - -static inline u16 Lo16(u32 v) -{ - return v & 0xffff; -} - - -static inline u16 RotR1(u16 v) -{ - return (v >> 1) | ((v & 0x0001) << 15); -} - - -static inline u16 tkip_S(u16 val) +static u8 *write_tkip_iv(u8 *pos, u16 iv16) { - u16 a = tkip_sbox[Hi8(val)]; - - return tkip_sbox[Lo8(val)] ^ Hi8(a) ^ (Lo8(a) << 8); + *pos++ = iv16 >> 8; + *pos++ = ((iv16 >> 8) | 0x20) & 0x7f; + *pos++ = iv16 & 0xFF; + return pos; } - - -/* P1K := Phase1(TA, TK, TSC) +/* + * P1K := Phase1(TA, TK, TSC) * TA = transmitter address (48 bits) * TK = dot11DefaultKeyValue or dot11KeyMappingValue (128 bits) * TSC = TKIP sequence counter (48 bits, only 32 msb bits used) * P1K: 80 bits */ -static void tkip_mixing_phase1(const u8 *ta, const u8 *tk, u32 tsc_IV32, - u16 *p1k) +static void tkip_mixing_phase1(const u8 *tk, struct tkip_ctx *ctx, + const u8 *ta, u32 tsc_IV32) { int i, j; + u16 *p1k = ctx->p1k; - p1k[0] = Lo16(tsc_IV32); - p1k[1] = Hi16(tsc_IV32); - p1k[2] = Mk16(ta[1], ta[0]); - p1k[3] = Mk16(ta[3], ta[2]); - p1k[4] = Mk16(ta[5], ta[4]); + p1k[0] = tsc_IV32 & 0xFFFF; + p1k[1] = tsc_IV32 >> 16; + p1k[2] = get_unaligned_le16(ta + 0); + p1k[3] = get_unaligned_le16(ta + 2); + p1k[4] = get_unaligned_le16(ta + 4); for (i = 0; i < PHASE1_LOOP_COUNT; i++) { j = 2 * (i & 1); - p1k[0] += tkip_S(p1k[4] ^ Mk16(tk[ 1 + j], tk[ 0 + j])); - p1k[1] += tkip_S(p1k[0] ^ Mk16(tk[ 5 + j], tk[ 4 + j])); - p1k[2] += tkip_S(p1k[1] ^ Mk16(tk[ 9 + j], tk[ 8 + j])); - p1k[3] += tkip_S(p1k[2] ^ Mk16(tk[13 + j], tk[12 + j])); - p1k[4] += tkip_S(p1k[3] ^ Mk16(tk[ 1 + j], tk[ 0 + j])) + i; + p1k[0] += tkipS(p1k[4] ^ get_unaligned_le16(tk + 0 + j)); + p1k[1] += tkipS(p1k[0] ^ get_unaligned_le16(tk + 4 + j)); + p1k[2] += tkipS(p1k[1] ^ get_unaligned_le16(tk + 8 + j)); + p1k[3] += tkipS(p1k[2] ^ get_unaligned_le16(tk + 12 + j)); + p1k[4] += tkipS(p1k[3] ^ get_unaligned_le16(tk + 0 + j)) + i; } + ctx->initialized = 1; } - -static void tkip_mixing_phase2(const u16 *p1k, const u8 *tk, u16 tsc_IV16, - u8 *rc4key) +static void tkip_mixing_phase2(const u8 *tk, struct tkip_ctx *ctx, + u16 tsc_IV16, u8 *rc4key) { u16 ppk[6]; + const u16 *p1k = ctx->p1k; int i; ppk[0] = p1k[0]; @@ -148,70 +116,35 @@ static void tkip_mixing_phase2(const u16 *p1k, const u8 *tk, u16 tsc_IV16, ppk[4] = p1k[4]; ppk[5] = p1k[4] + tsc_IV16; - ppk[0] += tkip_S(ppk[5] ^ Mk16(tk[ 1], tk[ 0])); - ppk[1] += tkip_S(ppk[0] ^ Mk16(tk[ 3], tk[ 2])); - ppk[2] += tkip_S(ppk[1] ^ Mk16(tk[ 5], tk[ 4])); - ppk[3] += tkip_S(ppk[2] ^ Mk16(tk[ 7], tk[ 6])); - ppk[4] += tkip_S(ppk[3] ^ Mk16(tk[ 9], tk[ 8])); - ppk[5] += tkip_S(ppk[4] ^ Mk16(tk[11], tk[10])); - ppk[0] += RotR1(ppk[5] ^ Mk16(tk[13], tk[12])); - ppk[1] += RotR1(ppk[0] ^ Mk16(tk[15], tk[14])); - ppk[2] += RotR1(ppk[1]); - ppk[3] += RotR1(ppk[2]); - ppk[4] += RotR1(ppk[3]); - ppk[5] += RotR1(ppk[4]); - - rc4key[0] = Hi8(tsc_IV16); - rc4key[1] = (Hi8(tsc_IV16) | 0x20) & 0x7f; - rc4key[2] = Lo8(tsc_IV16); - rc4key[3] = Lo8((ppk[5] ^ Mk16(tk[1], tk[0])) >> 1); - - for (i = 0; i < 6; i++) { - rc4key[4 + 2 * i] = Lo8(ppk[i]); - rc4key[5 + 2 * i] = Hi8(ppk[i]); - } + ppk[0] += tkipS(ppk[5] ^ get_unaligned_le16(tk + 0)); + ppk[1] += tkipS(ppk[0] ^ get_unaligned_le16(tk + 2)); + ppk[2] += tkipS(ppk[1] ^ get_unaligned_le16(tk + 4)); + ppk[3] += tkipS(ppk[2] ^ get_unaligned_le16(tk + 6)); + ppk[4] += tkipS(ppk[3] ^ get_unaligned_le16(tk + 8)); + ppk[5] += tkipS(ppk[4] ^ get_unaligned_le16(tk + 10)); + ppk[0] += ror16(ppk[5] ^ get_unaligned_le16(tk + 12), 1); + ppk[1] += ror16(ppk[0] ^ get_unaligned_le16(tk + 14), 1); + ppk[2] += ror16(ppk[1], 1); + ppk[3] += ror16(ppk[2], 1); + ppk[4] += ror16(ppk[3], 1); + ppk[5] += ror16(ppk[4], 1); + + rc4key = write_tkip_iv(rc4key, tsc_IV16); + *rc4key++ = ((ppk[5] ^ get_unaligned_le16(tk)) >> 1) & 0xFF; + + for (i = 0; i < 6; i++) + put_unaligned_le16(ppk[i], rc4key + 2 * i); } - /* Add TKIP IV and Ext. IV at @pos. @iv0, @iv1, and @iv2 are the first octets * of the IV. Returns pointer to the octet following IVs (i.e., beginning of * the packet payload). */ -u8 * ieee80211_tkip_add_iv(u8 *pos, struct ieee80211_key *key, - u8 iv0, u8 iv1, u8 iv2) +u8 *ieee80211_tkip_add_iv(u8 *pos, struct ieee80211_key *key, u16 iv16) { - *pos++ = iv0; - *pos++ = iv1; - *pos++ = iv2; + pos = write_tkip_iv(pos, iv16); *pos++ = (key->conf.keyidx << 6) | (1 << 5) /* Ext IV */; - *pos++ = key->u.tkip.iv32 & 0xff; - *pos++ = (key->u.tkip.iv32 >> 8) & 0xff; - *pos++ = (key->u.tkip.iv32 >> 16) & 0xff; - *pos++ = (key->u.tkip.iv32 >> 24) & 0xff; - return pos; -} - - -void ieee80211_tkip_gen_phase1key(struct ieee80211_key *key, u8 *ta, - u16 *phase1key) -{ - tkip_mixing_phase1(ta, &key->conf.key[ALG_TKIP_TEMP_ENCR_KEY], - key->u.tkip.iv32, phase1key); -} - -void ieee80211_tkip_gen_rc4key(struct ieee80211_key *key, u8 *ta, - u8 *rc4key) -{ - /* Calculate per-packet key */ - if (key->u.tkip.iv16 == 0 || !key->u.tkip.tx_initialized) { - /* IV16 wrapped around - perform TKIP phase 1 */ - tkip_mixing_phase1(ta, &key->conf.key[ALG_TKIP_TEMP_ENCR_KEY], - key->u.tkip.iv32, key->u.tkip.p1k); - key->u.tkip.tx_initialized = 1; - } - - tkip_mixing_phase2(key->u.tkip.p1k, - &key->conf.key[ALG_TKIP_TEMP_ENCR_KEY], - key->u.tkip.iv16, rc4key); + put_unaligned_le32(key->u.tkip.tx.iv32, pos); + return pos + 4; } void ieee80211_get_tkip_key(struct ieee80211_key_conf *keyconf, @@ -220,48 +153,44 @@ void ieee80211_get_tkip_key(struct ieee80211_key_conf *keyconf, { struct ieee80211_key *key = (struct ieee80211_key *) container_of(keyconf, struct ieee80211_key, conf); - struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; - u8 *data = (u8 *) hdr; - u16 fc = le16_to_cpu(hdr->frame_control); - int hdr_len = ieee80211_get_hdrlen(fc); - u8 *ta = hdr->addr2; + struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data; + u8 *data; + const u8 *tk; + struct tkip_ctx *ctx; u16 iv16; u32 iv32; - iv16 = data[hdr_len] << 8; - iv16 += data[hdr_len + 2]; - iv32 = data[hdr_len + 4] | (data[hdr_len + 5] << 8) | - (data[hdr_len + 6] << 16) | (data[hdr_len + 7] << 24); + data = (u8 *)hdr + ieee80211_hdrlen(hdr->frame_control); + iv16 = data[2] | (data[0] << 8); + iv32 = get_unaligned_le32(&data[4]); + + tk = &key->conf.key[NL80211_TKIP_DATA_OFFSET_ENCR_KEY]; + ctx = &key->u.tkip.tx; -#ifdef CONFIG_TKIP_DEBUG +#ifdef CONFIG_MAC80211_TKIP_DEBUG printk(KERN_DEBUG "TKIP encrypt: iv16 = 0x%04x, iv32 = 0x%08x\n", iv16, iv32); - if (iv32 != key->u.tkip.iv32) { + if (iv32 != ctx->iv32) { printk(KERN_DEBUG "skb: iv32 = 0x%08x key: iv32 = 0x%08x\n", - iv32, key->u.tkip.iv32); + iv32, ctx->iv32); printk(KERN_DEBUG "Wrap around of iv16 in the middle of a " "fragmented packet\n"); } -#endif /* CONFIG_TKIP_DEBUG */ +#endif /* Update the p1k only when the iv16 in the packet wraps around, this * might occur after the wrap around of iv16 in the key in case of * fragmented packets. */ - if (iv16 == 0 || !key->u.tkip.tx_initialized) { - /* IV16 wrapped around - perform TKIP phase 1 */ - tkip_mixing_phase1(ta, &key->conf.key[ALG_TKIP_TEMP_ENCR_KEY], - iv32, key->u.tkip.p1k); - key->u.tkip.tx_initialized = 1; - } + if (iv16 == 0 || !ctx->initialized) + tkip_mixing_phase1(tk, ctx, hdr->addr2, iv32); if (type == IEEE80211_TKIP_P1_KEY) { - memcpy(outkey, key->u.tkip.p1k, sizeof(u16) * 5); + memcpy(outkey, ctx->p1k, sizeof(u16) * 5); return; } - tkip_mixing_phase2(key->u.tkip.p1k, - &key->conf.key[ALG_TKIP_TEMP_ENCR_KEY], iv16, outkey); + tkip_mixing_phase2(tk, ctx, iv16, outkey); } EXPORT_SYMBOL(ieee80211_get_tkip_key); @@ -275,13 +204,19 @@ void ieee80211_tkip_encrypt_data(struct crypto_blkcipher *tfm, u8 *pos, size_t payload_len, u8 *ta) { u8 rc4key[16]; + struct tkip_ctx *ctx = &key->u.tkip.tx; + const u8 *tk = &key->conf.key[NL80211_TKIP_DATA_OFFSET_ENCR_KEY]; + + /* Calculate per-packet key */ + if (ctx->iv16 == 0 || !ctx->initialized) + tkip_mixing_phase1(tk, ctx, ta, ctx->iv32); + + tkip_mixing_phase2(tk, ctx, ctx->iv16, rc4key); - ieee80211_tkip_gen_rc4key(key, ta, rc4key); - pos = ieee80211_tkip_add_iv(pos, key, rc4key[0], rc4key[1], rc4key[2]); + pos = ieee80211_tkip_add_iv(pos, key, key->u.tkip.tx.iv16); ieee80211_wep_encrypt_data(tfm, rc4key, 16, pos, payload_len); } - /* Decrypt packet payload with TKIP using @key. @pos is a pointer to the * beginning of the buffer containing IEEE 802.11 header payload, i.e., * including IV, Ext. IV, real data, Michael MIC, ICV. @payload_len is the @@ -296,15 +231,16 @@ int ieee80211_tkip_decrypt_data(struct crypto_blkcipher *tfm, u32 iv16; u8 rc4key[16], keyid, *pos = payload; int res; + const u8 *tk = &key->conf.key[NL80211_TKIP_DATA_OFFSET_ENCR_KEY]; if (payload_len < 12) return -1; iv16 = (pos[0] << 8) | pos[2]; keyid = pos[3]; - iv32 = pos[4] | (pos[5] << 8) | (pos[6] << 16) | (pos[7] << 24); + iv32 = get_unaligned_le32(pos + 4); pos += 8; -#ifdef CONFIG_TKIP_DEBUG +#ifdef CONFIG_MAC80211_TKIP_DEBUG { int i; printk(KERN_DEBUG "TKIP decrypt: data(len=%zd)", payload_len); @@ -314,7 +250,7 @@ int ieee80211_tkip_decrypt_data(struct crypto_blkcipher *tfm, printk(KERN_DEBUG "TKIP decrypt: iv16=%04x iv32=%08x\n", iv16, iv32); } -#endif /* CONFIG_TKIP_DEBUG */ +#endif if (!(keyid & (1 << 5))) return TKIP_DECRYPT_NO_EXT_IV; @@ -322,50 +258,48 @@ int ieee80211_tkip_decrypt_data(struct crypto_blkcipher *tfm, if ((keyid >> 6) != key->conf.keyidx) return TKIP_DECRYPT_INVALID_KEYIDX; - if (key->u.tkip.rx_initialized[queue] && - (iv32 < key->u.tkip.iv32_rx[queue] || - (iv32 == key->u.tkip.iv32_rx[queue] && - iv16 <= key->u.tkip.iv16_rx[queue]))) { -#ifdef CONFIG_TKIP_DEBUG + if (key->u.tkip.rx[queue].initialized && + (iv32 < key->u.tkip.rx[queue].iv32 || + (iv32 == key->u.tkip.rx[queue].iv32 && + iv16 <= key->u.tkip.rx[queue].iv16))) { +#ifdef CONFIG_MAC80211_TKIP_DEBUG DECLARE_MAC_BUF(mac); printk(KERN_DEBUG "TKIP replay detected for RX frame from " "%s (RX IV (%04x,%02x) <= prev. IV (%04x,%02x)\n", print_mac(mac, ta), - iv32, iv16, key->u.tkip.iv32_rx[queue], - key->u.tkip.iv16_rx[queue]); -#endif /* CONFIG_TKIP_DEBUG */ + iv32, iv16, key->u.tkip.rx[queue].iv32, + key->u.tkip.rx[queue].iv16); +#endif return TKIP_DECRYPT_REPLAY; } if (only_iv) { res = TKIP_DECRYPT_OK; - key->u.tkip.rx_initialized[queue] = 1; + key->u.tkip.rx[queue].initialized = 1; goto done; } - if (!key->u.tkip.rx_initialized[queue] || - key->u.tkip.iv32_rx[queue] != iv32) { - key->u.tkip.rx_initialized[queue] = 1; + if (!key->u.tkip.rx[queue].initialized || + key->u.tkip.rx[queue].iv32 != iv32) { /* IV16 wrapped around - perform TKIP phase 1 */ - tkip_mixing_phase1(ta, &key->conf.key[ALG_TKIP_TEMP_ENCR_KEY], - iv32, key->u.tkip.p1k_rx[queue]); -#ifdef CONFIG_TKIP_DEBUG + tkip_mixing_phase1(tk, &key->u.tkip.rx[queue], ta, iv32); +#ifdef CONFIG_MAC80211_TKIP_DEBUG { int i; + u8 key_offset = NL80211_TKIP_DATA_OFFSET_ENCR_KEY; DECLARE_MAC_BUF(mac); printk(KERN_DEBUG "TKIP decrypt: Phase1 TA=%s" " TK=", print_mac(mac, ta)); for (i = 0; i < 16; i++) printk("%02x ", - key->conf.key[ - ALG_TKIP_TEMP_ENCR_KEY + i]); + key->conf.key[key_offset + i]); printk("\n"); printk(KERN_DEBUG "TKIP decrypt: P1K="); for (i = 0; i < 5; i++) - printk("%04x ", key->u.tkip.p1k_rx[queue][i]); + printk("%04x ", key->u.tkip.rx[queue].p1k[i]); printk("\n"); } -#endif /* CONFIG_TKIP_DEBUG */ +#endif if (key->local->ops->update_tkip_key && key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) { u8 bcast[ETH_ALEN] = @@ -377,14 +311,12 @@ int ieee80211_tkip_decrypt_data(struct crypto_blkcipher *tfm, key->local->ops->update_tkip_key( local_to_hw(key->local), &key->conf, - sta_addr, iv32, key->u.tkip.p1k_rx[queue]); + sta_addr, iv32, key->u.tkip.rx[queue].p1k); } } - tkip_mixing_phase2(key->u.tkip.p1k_rx[queue], - &key->conf.key[ALG_TKIP_TEMP_ENCR_KEY], - iv16, rc4key); -#ifdef CONFIG_TKIP_DEBUG + tkip_mixing_phase2(tk, &key->u.tkip.rx[queue], iv16, rc4key); +#ifdef CONFIG_MAC80211_TKIP_DEBUG { int i; printk(KERN_DEBUG "TKIP decrypt: Phase2 rc4key="); @@ -392,7 +324,7 @@ int ieee80211_tkip_decrypt_data(struct crypto_blkcipher *tfm, printk("%02x ", rc4key[i]); printk("\n"); } -#endif /* CONFIG_TKIP_DEBUG */ +#endif res = ieee80211_wep_decrypt_data(tfm, rc4key, 16, pos, payload_len - 12); done: @@ -409,5 +341,3 @@ int ieee80211_tkip_decrypt_data(struct crypto_blkcipher *tfm, return res; } - - |