From 8c046c8c64ba81dd87468ddaf2db4a5d926b988b Mon Sep 17 00:00:00 2001 From: Harvey Harrison Date: Fri, 2 May 2008 13:47:45 -0700 Subject: [PATCH] mac80211: tkip.c use kernel-provided infrastructure Use kernel-provided bit rotation and unaligned access infrastructure rather than opencoding it. Some minor spacing adjustments as well. Signed-off-by: Harvey Harrison Cc: "John W. Linville" Signed-off-by: Andrew Morton Signed-off-by: John W. Linville --- net/mac80211/tkip.c | 145 ++++++++++++++------------------------------ 1 file changed, 46 insertions(+), 99 deletions(-) diff --git a/net/mac80211/tkip.c b/net/mac80211/tkip.c index 09093da24a..a7c3febc5a 100644 --- a/net/mac80211/tkip.c +++ b/net/mac80211/tkip.c @@ -8,23 +8,22 @@ */ #include +#include #include #include +#include #include #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, @@ -61,53 +60,13 @@ static const u16 tkip_sbox[256] = 0x82C3, 0x29B0, 0x5A77, 0x1E11, 0x7BCB, 0xA8FC, 0x6DD6, 0x2C3A, }; - -static inline u16 Mk16(u8 x, u8 y) -{ - return ((u16) x << 8) | (u16) y; -} - - -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) +static u16 tkipS(u16 val) { - return (v >> 1) | ((v & 0x0001) << 15); -} - - -static inline u16 tkip_S(u16 val) -{ - u16 a = tkip_sbox[Hi8(val)]; - - return tkip_sbox[Lo8(val)] ^ Hi8(a) ^ (Lo8(a) << 8); + return tkip_sbox[val & 0xff] ^ swab16(tkip_sbox[val >> 8]); } - - -/* 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) @@ -118,23 +77,22 @@ static void tkip_mixing_phase1(const u8 *ta, const u8 *tk, u32 tsc_IV32, { int i, j; - 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; } } - static void tkip_mixing_phase2(const u16 *p1k, const u8 *tk, u16 tsc_IV16, u8 *rc4key) { @@ -148,31 +106,29 @@ 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[0] = tsc_IV16 >> 8; + rc4key[1] = ((tsc_IV16 >> 8) | 0x20) & 0x7f; + rc4key[2] = tsc_IV16 & 0xFF; + rc4key[3] = ((ppk[5] ^ get_unaligned_le16(tk)) >> 1) & 0xFF; + + rc4key += 4; + 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). */ @@ -183,14 +139,10 @@ u8 * ieee80211_tkip_add_iv(u8 *pos, struct ieee80211_key *key, *pos++ = iv1; *pos++ = iv2; *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; + put_unaligned_le32(key->u.tkip.iv32, pos); + return pos + 4; } - void ieee80211_tkip_gen_phase1key(struct ieee80211_key *key, u8 *ta, u16 *phase1key) { @@ -228,10 +180,8 @@ void ieee80211_get_tkip_key(struct ieee80211_key_conf *keyconf, 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); + iv16 = data[hdr_len + 2] | (data[hdr_len] << 8); + iv32 = get_unaligned_le32(data + hdr_len + 4); #ifdef CONFIG_TKIP_DEBUG printk(KERN_DEBUG "TKIP encrypt: iv16 = 0x%04x, iv32 = 0x%08x\n", @@ -281,7 +231,6 @@ void ieee80211_tkip_encrypt_data(struct crypto_blkcipher *tfm, 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 @@ -302,7 +251,7 @@ int ieee80211_tkip_decrypt_data(struct crypto_blkcipher *tfm, 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 { @@ -409,5 +358,3 @@ int ieee80211_tkip_decrypt_data(struct crypto_blkcipher *tfm, return res; } - - -- 2.39.5