diff options
Diffstat (limited to 'package/d80211/src/tkip.c')
| -rw-r--r-- | package/d80211/src/tkip.c | 341 |
1 files changed, 341 insertions, 0 deletions
diff --git a/package/d80211/src/tkip.c b/package/d80211/src/tkip.c new file mode 100644 index 0000000000..11966e0e3c --- /dev/null +++ b/package/d80211/src/tkip.c @@ -0,0 +1,341 @@ +/* + * Copyright 2002-2004, Instant802 Networks, Inc. + * Copyright 2005, Devicescape Software, Inc. + * + * 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. + */ + +#include <linux/kernel.h> +#include <linux/types.h> +#include <linux/netdevice.h> + +#include <net/d80211.h> +#include "ieee80211_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 */ +static const u16 tkip_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 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) +{ + 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); +} + + + +/* 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) +{ + 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]); + + 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; + } +} + + +static void tkip_mixing_phase2(const u16 *p1k, const u8 *tk, u16 tsc_IV16, + u8 *rc4key) +{ + u16 ppk[6]; + int i; + + ppk[0] = p1k[0]; + ppk[1] = p1k[1]; + ppk[2] = p1k[2]; + ppk[3] = p1k[3]; + 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]); + } +} + + +/* 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) +{ + *pos++ = iv0; + *pos++ = iv1; + *pos++ = iv2; + *pos++ = (key->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->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->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->key[ALG_TKIP_TEMP_ENCR_KEY], + key->u.tkip.iv16, rc4key); +} + +/* Encrypt packet payload with TKIP using @key. @pos is a pointer to the + * beginning of the buffer containing payload. This payload must include + * headroom of eight octets for IV and Ext. IV and taildroom of four octets + * for ICV. @payload_len is the length of payload (_not_ including extra + * headroom and tailroom). @ta is the transmitter addresses. */ +void ieee80211_tkip_encrypt_data(struct crypto_blkcipher *tfm, + struct ieee80211_key *key, + u8 *pos, size_t payload_len, u8 *ta) +{ + u8 rc4key[16]; + + ieee80211_tkip_gen_rc4key(key, ta, rc4key); + pos = ieee80211_tkip_add_iv(pos, key, rc4key[0], rc4key[1], rc4key[2]); + 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 + * length of payload, including IV, Ext. IV, MIC, ICV. */ +int ieee80211_tkip_decrypt_data(struct crypto_blkcipher *tfm, + struct ieee80211_key *key, + u8 *payload, size_t payload_len, u8 *ta, + int only_iv, int queue) +{ + u32 iv32; + u32 iv16; + u8 rc4key[16], keyid, *pos = payload; + int res; + + 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); + pos += 8; +#ifdef CONFIG_TKIP_DEBUG + { + int i; + printk(KERN_DEBUG "TKIP decrypt: data(len=%zd)", payload_len); + for (i = 0; i < payload_len; i++) + printk(" %02x", payload[i]); + printk("\n"); + printk(KERN_DEBUG "TKIP decrypt: iv16=%04x iv32=%08x\n", + iv16, iv32); + } +#endif /* CONFIG_TKIP_DEBUG */ + + if (!(keyid & (1 << 5))) + return TKIP_DECRYPT_NO_EXT_IV; + + if ((keyid >> 6) != key->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 + printk(KERN_DEBUG "TKIP replay detected for RX frame from " + MAC_FMT " (RX IV (%04x,%02x) <= prev. IV (%04x,%02x)\n", + MAC_ARG(ta), + iv32, iv16, key->u.tkip.iv32_rx[queue], + key->u.tkip.iv16_rx[queue]); +#endif /* CONFIG_TKIP_DEBUG */ + return TKIP_DECRYPT_REPLAY; + } + + if (only_iv) { + res = TKIP_DECRYPT_OK; + key->u.tkip.rx_initialized[queue] = 1; + goto done; + } + + if (!key->u.tkip.rx_initialized[queue] || + key->u.tkip.iv32_rx[queue] != iv32) { + key->u.tkip.rx_initialized[queue] = 1; + /* IV16 wrapped around - perform TKIP phase 1 */ + tkip_mixing_phase1(ta, &key->key[ALG_TKIP_TEMP_ENCR_KEY], + iv32, key->u.tkip.p1k_rx[queue]); +#ifdef CONFIG_TKIP_DEBUG + { + int i; + printk(KERN_DEBUG "TKIP decrypt: Phase1 TA=" MAC_FMT + " TK=", MAC_ARG(ta)); + for (i = 0; i < 16; i++) + printk("%02x ", + key->key[ALG_TKIP_TEMP_ENCR_KEY + 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("\n"); + } +#endif /* CONFIG_TKIP_DEBUG */ + } + + tkip_mixing_phase2(key->u.tkip.p1k_rx[queue], + &key->key[ALG_TKIP_TEMP_ENCR_KEY], + iv16, rc4key); +#ifdef CONFIG_TKIP_DEBUG + { + int i; + printk(KERN_DEBUG "TKIP decrypt: Phase2 rc4key="); + for (i = 0; i < 16; i++) + printk("%02x ", rc4key[i]); + printk("\n"); + } +#endif /* CONFIG_TKIP_DEBUG */ + + res = ieee80211_wep_decrypt_data(tfm, rc4key, 16, pos, payload_len - 12); + done: + if (res == TKIP_DECRYPT_OK) { + /* FIX: these should be updated only after Michael MIC has been + * verified */ + /* Record previously received IV */ + key->u.tkip.iv32_rx[queue] = iv32; + key->u.tkip.iv16_rx[queue] = iv16; + } + + return res; +} + + |