| /* |
| * 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/bitops.h> |
| #include <linux/types.h> |
| #include <linux/netdevice.h> |
| #include <asm/unaligned.h> |
| |
| #include <net/mac80211.h> |
| #include "driver-ops.h" |
| #include "key.h" |
| #include "tkip.h" |
| #include "wep.h" |
| |
| #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 u16 tkipS(u16 val) |
| { |
| return tkip_sbox[val & 0xff] ^ swab16(tkip_sbox[val >> 8]); |
| } |
| |
| static u8 *write_tkip_iv(u8 *pos, u16 iv16) |
| { |
| *pos++ = iv16 >> 8; |
| *pos++ = ((iv16 >> 8) | 0x20) & 0x7f; |
| *pos++ = iv16 & 0xFF; |
| return pos; |
| } |
| |
| /* |
| * 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 *tk, struct tkip_ctx *ctx, |
| const u8 *ta, u32 tsc_IV32) |
| { |
| int i, j; |
| u16 *p1k = ctx->p1k; |
| |
| 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] += 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 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]; |
| ppk[1] = p1k[1]; |
| ppk[2] = p1k[2]; |
| ppk[3] = p1k[3]; |
| ppk[4] = p1k[4]; |
| ppk[5] = p1k[4] + tsc_IV16; |
| |
| 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, u16 iv16) |
| { |
| pos = write_tkip_iv(pos, iv16); |
| *pos++ = (key->conf.keyidx << 6) | (1 << 5) /* Ext IV */; |
| put_unaligned_le32(key->u.tkip.tx.iv32, pos); |
| return pos + 4; |
| } |
| |
| void ieee80211_get_tkip_key(struct ieee80211_key_conf *keyconf, |
| struct sk_buff *skb, enum ieee80211_tkip_key_type type, |
| u8 *outkey) |
| { |
| 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; |
| const u8 *tk; |
| struct tkip_ctx *ctx; |
| u16 iv16; |
| u32 iv32; |
| |
| 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_MAC80211_TKIP_DEBUG |
| printk(KERN_DEBUG "TKIP encrypt: iv16 = 0x%04x, iv32 = 0x%08x\n", |
| iv16, iv32); |
| |
| if (iv32 != ctx->iv32) { |
| printk(KERN_DEBUG "skb: iv32 = 0x%08x key: iv32 = 0x%08x\n", |
| iv32, ctx->iv32); |
| printk(KERN_DEBUG "Wrap around of iv16 in the middle of a " |
| "fragmented packet\n"); |
| } |
| #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 || !ctx->initialized) |
| tkip_mixing_phase1(tk, ctx, hdr->addr2, iv32); |
| |
| if (type == IEEE80211_TKIP_P1_KEY) { |
| memcpy(outkey, ctx->p1k, sizeof(u16) * 5); |
| return; |
| } |
| |
| tkip_mixing_phase2(tk, ctx, iv16, outkey); |
| } |
| EXPORT_SYMBOL(ieee80211_get_tkip_key); |
| |
| /* 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]; |
| 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); |
| |
| 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 |
| * 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, |
| u8 *ra, int only_iv, int queue, |
| u32 *out_iv32, u16 *out_iv16) |
| { |
| u32 iv32; |
| 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 = get_unaligned_le32(pos + 4); |
| pos += 8; |
| #ifdef CONFIG_MAC80211_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 |
| |
| if (!(keyid & (1 << 5))) |
| return TKIP_DECRYPT_NO_EXT_IV; |
| |
| if ((keyid >> 6) != key->conf.keyidx) |
| return TKIP_DECRYPT_INVALID_KEYIDX; |
| |
| 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 |
| printk(KERN_DEBUG "TKIP replay detected for RX frame from " |
| "%pM (RX IV (%04x,%02x) <= prev. IV (%04x,%02x)\n", |
| ta, |
| 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[queue].initialized = 1; |
| goto done; |
| } |
| |
| if (!key->u.tkip.rx[queue].initialized || |
| key->u.tkip.rx[queue].iv32 != iv32) { |
| /* IV16 wrapped around - perform TKIP phase 1 */ |
| 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; |
| printk(KERN_DEBUG "TKIP decrypt: Phase1 TA=%pM" |
| " TK=", ta); |
| for (i = 0; i < 16; i++) |
| printk("%02x ", |
| 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.rx[queue].p1k[i]); |
| printk("\n"); |
| } |
| #endif |
| if (key->local->ops->update_tkip_key && |
| key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) { |
| static const u8 bcast[ETH_ALEN] = |
| {0xff, 0xff, 0xff, 0xff, 0xff, 0xff}; |
| const u8 *sta_addr = key->sta->sta.addr; |
| |
| if (is_multicast_ether_addr(ra)) |
| sta_addr = bcast; |
| |
| drv_update_tkip_key(key->local, &key->conf, sta_addr, |
| iv32, key->u.tkip.rx[queue].p1k); |
| } |
| } |
| |
| 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="); |
| for (i = 0; i < 16; i++) |
| printk("%02x ", rc4key[i]); |
| printk("\n"); |
| } |
| #endif |
| |
| res = ieee80211_wep_decrypt_data(tfm, rc4key, 16, pos, payload_len - 12); |
| done: |
| if (res == TKIP_DECRYPT_OK) { |
| /* |
| * Record previously received IV, will be copied into the |
| * key information after MIC verification. It is possible |
| * that we don't catch replays of fragments but that's ok |
| * because the Michael MIC verication will then fail. |
| */ |
| *out_iv32 = iv32; |
| *out_iv16 = iv16; |
| } |
| |
| return res; |
| } |