/*- * Copyright (c) 2002-2005 Sam Leffler, Errno Consulting * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. The name of the author may not be used to endorse or promote products * derived from this software without specific prior written permission. * * Alternatively, this software may be distributed under the terms of the * GNU General Public License ("GPL") version 2 as published by the Free * Software Foundation. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ #include #ifdef __FreeBSD__ __FBSDID("$FreeBSD: src/sys/net80211/ieee80211_crypto_tkip.c,v 1.10 2005/08/08 18:46:35 sam Exp $"); #endif #ifdef __NetBSD__ __KERNEL_RCSID(0, "$NetBSD: ieee80211_crypto_tkip.c,v 1.5 2006/03/16 15:59:22 christos Exp $"); #endif /* * IEEE 802.11i TKIP crypto support. * * Part of this module is derived from similar code in the Host * AP driver. The code is used with the consent of the author and * it's license is included below. */ #include #include #include #include #include #include #include #include #include #include #include static void *tkip_attach(struct ieee80211com *, struct ieee80211_key *); static void tkip_detach(struct ieee80211_key *); static int tkip_setkey(struct ieee80211_key *); static int tkip_encap(struct ieee80211_key *, struct mbuf *m, u_int8_t keyid); static int tkip_enmic(struct ieee80211_key *, struct mbuf *, int); static int tkip_decap(struct ieee80211_key *, struct mbuf *, int); static int tkip_demic(struct ieee80211_key *, struct mbuf *, int); const struct ieee80211_cipher ieee80211_cipher_tkip = { .ic_name = "TKIP", .ic_cipher = IEEE80211_CIPHER_TKIP, .ic_header = IEEE80211_WEP_IVLEN + IEEE80211_WEP_KIDLEN + IEEE80211_WEP_EXTIVLEN, .ic_trailer = IEEE80211_WEP_CRCLEN, .ic_miclen = IEEE80211_WEP_MICLEN, .ic_attach = tkip_attach, .ic_detach = tkip_detach, .ic_setkey = tkip_setkey, .ic_encap = tkip_encap, .ic_decap = tkip_decap, .ic_enmic = tkip_enmic, .ic_demic = tkip_demic, }; #define tkip ieee80211_cipher_tkip typedef uint8_t u8; typedef uint16_t u16; typedef uint32_t __u32; typedef uint32_t u32; struct tkip_ctx { struct ieee80211com *tc_ic; /* for diagnostics */ u16 tx_ttak[5]; int tx_phase1_done; u8 tx_rc4key[16]; /* XXX for test module; make locals? */ u16 rx_ttak[5]; int rx_phase1_done; u8 rx_rc4key[16]; /* XXX for test module; make locals? */ uint64_t rx_rsc; /* held until MIC verified */ }; static void michael_mic(struct tkip_ctx *, const u8 *key, struct mbuf *m, u_int off, size_t data_len, u8 mic[IEEE80211_WEP_MICLEN]); static int tkip_encrypt(struct tkip_ctx *, struct ieee80211_key *, struct mbuf *, int hdr_len); static int tkip_decrypt(struct tkip_ctx *, struct ieee80211_key *, struct mbuf *, int hdr_len); static void * tkip_attach(struct ieee80211com *ic, struct ieee80211_key *k) { struct tkip_ctx *ctx; MALLOC(ctx, struct tkip_ctx *, sizeof(struct tkip_ctx), M_DEVBUF, M_NOWAIT | M_ZERO); if (ctx == NULL) { ic->ic_stats.is_crypto_nomem++; return NULL; } ctx->tc_ic = ic; return ctx; } static void tkip_detach(struct ieee80211_key *k) { struct tkip_ctx *ctx = k->wk_private; FREE(ctx, M_DEVBUF); } static int tkip_setkey(struct ieee80211_key *k) { struct tkip_ctx *ctx = k->wk_private; if (k->wk_keylen != (128/NBBY)) { (void) ctx; /* XXX */ IEEE80211_DPRINTF(ctx->tc_ic, IEEE80211_MSG_CRYPTO, "%s: Invalid key length %u, expecting %u\n", __func__, k->wk_keylen, 128/NBBY); return 0; } k->wk_keytsc = 1; /* TSC starts at 1 */ return 1; } /* * Add privacy headers and do any s/w encryption required. */ static int tkip_encap(struct ieee80211_key *k, struct mbuf *m, u_int8_t keyid) { struct tkip_ctx *ctx = k->wk_private; struct ieee80211com *ic = ctx->tc_ic; u_int8_t *ivp; int hdrlen; /* * Handle TKIP counter measures requirement. */ if (ic->ic_flags & IEEE80211_F_COUNTERM) { #ifdef IEEE80211_DEBUG struct ieee80211_frame *wh = mtod(m, struct ieee80211_frame *); #endif IEEE80211_DPRINTF(ic, IEEE80211_MSG_CRYPTO, "[%s] Discard frame due to countermeasures (%s)\n", ether_sprintf(wh->i_addr2), __func__); ic->ic_stats.is_crypto_tkipcm++; return 0; } hdrlen = ieee80211_hdrspace(ic, mtod(m, void *)); /* * Copy down 802.11 header and add the IV, KeyID, and ExtIV. */ M_PREPEND(m, tkip.ic_header, M_NOWAIT); if (m == NULL) return 0; ivp = mtod(m, u_int8_t *); memmove(ivp, ivp + tkip.ic_header, hdrlen); ivp += hdrlen; ivp[0] = k->wk_keytsc >> 8; /* TSC1 */ ivp[1] = (ivp[0] | 0x20) & 0x7f; /* WEP seed */ ivp[2] = k->wk_keytsc >> 0; /* TSC0 */ ivp[3] = keyid | IEEE80211_WEP_EXTIV; /* KeyID | ExtID */ ivp[4] = k->wk_keytsc >> 16; /* TSC2 */ ivp[5] = k->wk_keytsc >> 24; /* TSC3 */ ivp[6] = k->wk_keytsc >> 32; /* TSC4 */ ivp[7] = k->wk_keytsc >> 40; /* TSC5 */ /* * Finally, do software encrypt if neeed. */ if (k->wk_flags & IEEE80211_KEY_SWCRYPT) { if (!tkip_encrypt(ctx, k, m, hdrlen)) return 0; /* NB: tkip_encrypt handles wk_keytsc */ } else k->wk_keytsc++; return 1; } /* * Add MIC to the frame as needed. */ static int tkip_enmic(struct ieee80211_key *k, struct mbuf *m, int force) { struct tkip_ctx *ctx = k->wk_private; if (force || (k->wk_flags & IEEE80211_KEY_SWMIC)) { struct ieee80211_frame *wh = mtod(m, struct ieee80211_frame *); struct ieee80211com *ic = ctx->tc_ic; int hdrlen; uint8_t mic[IEEE80211_WEP_MICLEN]; ic->ic_stats.is_crypto_tkipenmic++; hdrlen = ieee80211_hdrspace(ic, wh); michael_mic(ctx, k->wk_txmic, m, hdrlen, m->m_pkthdr.len - hdrlen, mic); return m_append(m, tkip.ic_miclen, mic); } return 1; } static __inline uint64_t READ_6(uint8_t b0, uint8_t b1, uint8_t b2, uint8_t b3, uint8_t b4, uint8_t b5) { uint32_t iv32 = (b0 << 0) | (b1 << 8) | (b2 << 16) | (b3 << 24); uint16_t iv16 = (b4 << 0) | (b5 << 8); return (((uint64_t)iv16) << 32) | iv32; } /* * Validate and strip privacy headers (and trailer) for a * received frame. If necessary, decrypt the frame using * the specified key. */ static int tkip_decap(struct ieee80211_key *k, struct mbuf *m, int hdrlen) { struct tkip_ctx *ctx = k->wk_private; struct ieee80211com *ic = ctx->tc_ic; struct ieee80211_frame *wh; uint8_t *ivp; /* * Header should have extended IV and sequence number; * verify the former and validate the latter. */ wh = mtod(m, struct ieee80211_frame *); ivp = mtod(m, uint8_t *) + hdrlen; if ((ivp[IEEE80211_WEP_IVLEN] & IEEE80211_WEP_EXTIV) == 0) { /* * No extended IV; discard frame. */ IEEE80211_DPRINTF(ctx->tc_ic, IEEE80211_MSG_CRYPTO, "[%s] missing ExtIV for TKIP cipher\n", ether_sprintf(wh->i_addr2)); ctx->tc_ic->ic_stats.is_rx_tkipformat++; return 0; } /* * Handle TKIP counter measures requirement. */ if (ic->ic_flags & IEEE80211_F_COUNTERM) { IEEE80211_DPRINTF(ic, IEEE80211_MSG_CRYPTO, "[%s] discard frame due to countermeasures (%s)\n", ether_sprintf(wh->i_addr2), __func__); ic->ic_stats.is_crypto_tkipcm++; return 0; } ctx->rx_rsc = READ_6(ivp[2], ivp[0], ivp[4], ivp[5], ivp[6], ivp[7]); if (ctx->rx_rsc <= k->wk_keyrsc) { /* * Replay violation; notify upper layer. */ ieee80211_notify_replay_failure(ctx->tc_ic, wh, k, ctx->rx_rsc); ctx->tc_ic->ic_stats.is_rx_tkipreplay++; return 0; } /* * NB: We can't update the rsc in the key until MIC is verified. * * We assume we are not preempted between doing the check above * and updating wk_keyrsc when stripping the MIC in tkip_demic. * Otherwise we might process another packet and discard it as * a replay. */ /* * Check if the device handled the decrypt in hardware. * If so we just strip the header; otherwise we need to * handle the decrypt in software. */ if ((k->wk_flags & IEEE80211_KEY_SWCRYPT) && !tkip_decrypt(ctx, k, m, hdrlen)) return 0; /* * Copy up 802.11 header and strip crypto bits. */ memmove(mtod(m, uint8_t *) + tkip.ic_header, mtod(m, void *), hdrlen); m_adj(m, tkip.ic_header); m_adj(m, -tkip.ic_trailer); return 1; } /* * Verify and strip MIC from the frame. */ static int tkip_demic(struct ieee80211_key *k, struct mbuf *m, int force) { struct tkip_ctx *ctx = k->wk_private; if (force || (k->wk_flags & IEEE80211_KEY_SWMIC)) { struct ieee80211_frame *wh = mtod(m, struct ieee80211_frame *); struct ieee80211com *ic = ctx->tc_ic; int hdrlen = ieee80211_hdrspace(ic, wh); u8 mic[IEEE80211_WEP_MICLEN]; u8 mic0[IEEE80211_WEP_MICLEN]; ic->ic_stats.is_crypto_tkipdemic++; michael_mic(ctx, k->wk_rxmic, m, hdrlen, m->m_pkthdr.len - (hdrlen + tkip.ic_miclen), mic); m_copydata(m, m->m_pkthdr.len - tkip.ic_miclen, tkip.ic_miclen, mic0); if (memcmp(mic, mic0, tkip.ic_miclen)) { /* NB: 802.11 layer handles statistic and debug msg */ ieee80211_notify_michael_failure(ic, wh, k->wk_rxkeyix != IEEE80211_KEYIX_NONE ? k->wk_rxkeyix : k->wk_keyix); return 0; } } /* * Strip MIC from the tail. */ m_adj(m, -tkip.ic_miclen); /* * Ok to update rsc now that MIC has been verified. */ k->wk_keyrsc = ctx->rx_rsc; return 1; } /* * Host AP crypt: host-based TKIP encryption implementation for Host AP driver * * Copyright (c) 2003-2004, Jouni Malinen * * 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. * * Alternatively, this software may be distributed under the terms of BSD * license. */ static const __u32 crc32_table[256] = { 0x00000000L, 0x77073096L, 0xee0e612cL, 0x990951baL, 0x076dc419L, 0x706af48fL, 0xe963a535L, 0x9e6495a3L, 0x0edb8832L, 0x79dcb8a4L, 0xe0d5e91eL, 0x97d2d988L, 0x09b64c2bL, 0x7eb17cbdL, 0xe7b82d07L, 0x90bf1d91L, 0x1db71064L, 0x6ab020f2L, 0xf3b97148L, 0x84be41deL, 0x1adad47dL, 0x6ddde4ebL, 0xf4d4b551L, 0x83d385c7L, 0x136c9856L, 0x646ba8c0L, 0xfd62f97aL, 0x8a65c9ecL, 0x14015c4fL, 0x63066cd9L, 0xfa0f3d63L, 0x8d080df5L, 0x3b6e20c8L, 0x4c69105eL, 0xd56041e4L, 0xa2677172L, 0x3c03e4d1L, 0x4b04d447L, 0xd20d85fdL, 0xa50ab56bL, 0x35b5a8faL, 0x42b2986cL, 0xdbbbc9d6L, 0xacbcf940L, 0x32d86ce3L, 0x45df5c75L, 0xdcd60dcfL, 0xabd13d59L, 0x26d930acL, 0x51de003aL, 0xc8d75180L, 0xbfd06116L, 0x21b4f4b5L, 0x56b3c423L, 0xcfba9599L, 0xb8bda50fL, 0x2802b89eL, 0x5f058808L, 0xc60cd9b2L, 0xb10be924L, 0x2f6f7c87L, 0x58684c11L, 0xc1611dabL, 0xb6662d3dL, 0x76dc4190L, 0x01db7106L, 0x98d220bcL, 0xefd5102aL, 0x71b18589L, 0x06b6b51fL, 0x9fbfe4a5L, 0xe8b8d433L, 0x7807c9a2L, 0x0f00f934L, 0x9609a88eL, 0xe10e9818L, 0x7f6a0dbbL, 0x086d3d2dL, 0x91646c97L, 0xe6635c01L, 0x6b6b51f4L, 0x1c6c6162L, 0x856530d8L, 0xf262004eL, 0x6c0695edL, 0x1b01a57bL, 0x8208f4c1L, 0xf50fc457L, 0x65b0d9c6L, 0x12b7e950L, 0x8bbeb8eaL, 0xfcb9887cL, 0x62dd1ddfL, 0x15da2d49L, 0x8cd37cf3L, 0xfbd44c65L, 0x4db26158L, 0x3ab551ceL, 0xa3bc0074L, 0xd4bb30e2L, 0x4adfa541L, 0x3dd895d7L, 0xa4d1c46dL, 0xd3d6f4fbL, 0x4369e96aL, 0x346ed9fcL, 0xad678846L, 0xda60b8d0L, 0x44042d73L, 0x33031de5L, 0xaa0a4c5fL, 0xdd0d7cc9L, 0x5005713cL, 0x270241aaL, 0xbe0b1010L, 0xc90c2086L, 0x5768b525L, 0x206f85b3L, 0xb966d409L, 0xce61e49fL, 0x5edef90eL, 0x29d9c998L, 0xb0d09822L, 0xc7d7a8b4L, 0x59b33d17L, 0x2eb40d81L, 0xb7bd5c3bL, 0xc0ba6cadL, 0xedb88320L, 0x9abfb3b6L, 0x03b6e20cL, 0x74b1d29aL, 0xead54739L, 0x9dd277afL, 0x04db2615L, 0x73dc1683L, 0xe3630b12L, 0x94643b84L, 0x0d6d6a3eL, 0x7a6a5aa8L, 0xe40ecf0bL, 0x9309ff9dL, 0x0a00ae27L, 0x7d079eb1L, 0xf00f9344L, 0x8708a3d2L, 0x1e01f268L, 0x6906c2feL, 0xf762575dL, 0x806567cbL, 0x196c3671L, 0x6e6b06e7L, 0xfed41b76L, 0x89d32be0L, 0x10da7a5aL, 0x67dd4accL, 0xf9b9df6fL, 0x8ebeeff9L, 0x17b7be43L, 0x60b08ed5L, 0xd6d6a3e8L, 0xa1d1937eL, 0x38d8c2c4L, 0x4fdff252L, 0xd1bb67f1L, 0xa6bc5767L, 0x3fb506ddL, 0x48b2364bL, 0xd80d2bdaL, 0xaf0a1b4cL, 0x36034af6L, 0x41047a60L, 0xdf60efc3L, 0xa867df55L, 0x316e8eefL, 0x4669be79L, 0xcb61b38cL, 0xbc66831aL, 0x256fd2a0L, 0x5268e236L, 0xcc0c7795L, 0xbb0b4703L, 0x220216b9L, 0x5505262fL, 0xc5ba3bbeL, 0xb2bd0b28L, 0x2bb45a92L, 0x5cb36a04L, 0xc2d7ffa7L, 0xb5d0cf31L, 0x2cd99e8bL, 0x5bdeae1dL, 0x9b64c2b0L, 0xec63f226L, 0x756aa39cL, 0x026d930aL, 0x9c0906a9L, 0xeb0e363fL, 0x72076785L, 0x05005713L, 0x95bf4a82L, 0xe2b87a14L, 0x7bb12baeL, 0x0cb61b38L, 0x92d28e9bL, 0xe5d5be0dL, 0x7cdcefb7L, 0x0bdbdf21L, 0x86d3d2d4L, 0xf1d4e242L, 0x68ddb3f8L, 0x1fda836eL, 0x81be16cdL, 0xf6b9265bL, 0x6fb077e1L, 0x18b74777L, 0x88085ae6L, 0xff0f6a70L, 0x66063bcaL, 0x11010b5cL, 0x8f659effL, 0xf862ae69L, 0x616bffd3L, 0x166ccf45L, 0xa00ae278L, 0xd70dd2eeL, 0x4e048354L, 0x3903b3c2L, 0xa7672661L, 0xd06016f7L, 0x4969474dL, 0x3e6e77dbL, 0xaed16a4aL, 0xd9d65adcL, 0x40df0b66L, 0x37d83bf0L, 0xa9bcae53L, 0xdebb9ec5L, 0x47b2cf7fL, 0x30b5ffe9L, 0xbdbdf21cL, 0xcabac28aL, 0x53b39330L, 0x24b4a3a6L, 0xbad03605L, 0xcdd70693L, 0x54de5729L, 0x23d967bfL, 0xb3667a2eL, 0xc4614ab8L, 0x5d681b02L, 0x2a6f2b94L, 0xb40bbe37L, 0xc30c8ea1L, 0x5a05df1bL, 0x2d02ef8dL }; 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(const u16 *v) { return le16toh(*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; } } #ifndef _BYTE_ORDER #error "Don't know native byte order" #endif 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((const u16 *) &TK[0])); PPK[1] += _S_(PPK[0] ^ Mk16_le((const u16 *) &TK[2])); PPK[2] += _S_(PPK[1] ^ Mk16_le((const u16 *) &TK[4])); PPK[3] += _S_(PPK[2] ^ Mk16_le((const u16 *) &TK[6])); PPK[4] += _S_(PPK[3] ^ Mk16_le((const u16 *) &TK[8])); PPK[5] += _S_(PPK[4] ^ Mk16_le((const u16 *) &TK[10])); PPK[0] += RotR1(PPK[5] ^ Mk16_le((const u16 *) &TK[12])); PPK[1] += RotR1(PPK[0] ^ Mk16_le((const 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((const u16 *) &TK[0])) >> 1); #if _BYTE_ORDER == _BIG_ENDIAN { int i; for (i = 0; i < 6; i++) PPK[i] = (PPK[i] << 8) | (PPK[i] >> 8); } #endif } static void wep_encrypt(u8 *key, struct mbuf *m0, u_int off, size_t data_len, uint8_t icv[IEEE80211_WEP_CRCLEN]) { u32 i, j, k, crc; size_t buflen; u8 S[256]; u8 *pos; struct mbuf *m; #define S_SWAP(a,b) do { u8 t = S[a]; S[a] = S[b]; S[b] = t; } while(0) /* Setup RC4 state */ for (i = 0; i < 256; i++) S[i] = i; j = 0; for (i = 0; i < 256; i++) { j = (j + S[i] + key[i & 0x0f]) & 0xff; S_SWAP(i, j); } /* Compute CRC32 over unencrypted data and apply RC4 to data */ crc = ~0; i = j = 0; m = m0; pos = mtod(m, uint8_t *) + off; buflen = m->m_len - off; for (;;) { if (buflen > data_len) buflen = data_len; data_len -= buflen; for (k = 0; k < buflen; k++) { crc = crc32_table[(crc ^ *pos) & 0xff] ^ (crc >> 8); i = (i + 1) & 0xff; j = (j + S[i]) & 0xff; S_SWAP(i, j); *pos++ ^= S[(S[i] + S[j]) & 0xff]; } m = m->m_next; if (m == NULL) { IASSERT(data_len == 0, ("out of buffers with data_len %zu\n", data_len)); break; } pos = mtod(m, uint8_t *); buflen = m->m_len; } crc = ~crc; /* Append little-endian CRC32 and encrypt it to produce ICV */ icv[0] = crc; icv[1] = crc >> 8; icv[2] = crc >> 16; icv[3] = crc >> 24; for (k = 0; k < IEEE80211_WEP_CRCLEN; k++) { i = (i + 1) & 0xff; j = (j + S[i]) & 0xff; S_SWAP(i, j); icv[k] ^= S[(S[i] + S[j]) & 0xff]; } } static int wep_decrypt(u8 *key, struct mbuf *m, u_int off, size_t data_len) { u32 i, j, k, crc; u8 S[256]; u8 *pos, icv[4]; size_t buflen; /* Setup RC4 state */ for (i = 0; i < 256; i++) S[i] = i; j = 0; for (i = 0; i < 256; i++) { j = (j + S[i] + key[i & 0x0f]) & 0xff; S_SWAP(i, j); } /* Apply RC4 to data and compute CRC32 over decrypted data */ crc = ~0; i = j = 0; pos = mtod(m, uint8_t *) + off; buflen = m->m_len - off; for (;;) { if (buflen > data_len) buflen = data_len; data_len -= buflen; for (k = 0; k < buflen; k++) { i = (i + 1) & 0xff; j = (j + S[i]) & 0xff; S_SWAP(i, j); *pos ^= S[(S[i] + S[j]) & 0xff]; crc = crc32_table[(crc ^ *pos) & 0xff] ^ (crc >> 8); pos++; } m = m->m_next; if (m == NULL) { IASSERT(data_len == 0, ("out of buffers with data_len %zu\n", data_len)); break; } pos = mtod(m, uint8_t *); buflen = m->m_len; } crc = ~crc; /* Encrypt little-endian CRC32 and verify that it matches with the * received ICV */ icv[0] = crc; icv[1] = crc >> 8; icv[2] = crc >> 16; icv[3] = crc >> 24; for (k = 0; k < 4; k++) { i = (i + 1) & 0xff; j = (j + S[i]) & 0xff; S_SWAP(i, j); if ((icv[k] ^ S[(S[i] + S[j]) & 0xff]) != *pos++) { /* ICV mismatch - drop frame */ return -1; } } return 0; } static __inline u32 rotl(u32 val, int bits) { return (val << bits) | (val >> (32 - bits)); } static __inline u32 rotr(u32 val, int bits) { return (val >> bits) | (val << (32 - bits)); } static __inline u32 xswap(u32 val) { return ((val & 0x00ff00ff) << 8) | ((val & 0xff00ff00) >> 8); } #define michael_block(l, r) \ do { \ r ^= rotl(l, 17); \ l += r; \ r ^= xswap(l); \ l += r; \ r ^= rotl(l, 3); \ l += r; \ r ^= rotr(l, 2); \ l += r; \ } while (0) static __inline u32 get_le32_split(u8 b0, u8 b1, u8 b2, u8 b3) { return b0 | (b1 << 8) | (b2 << 16) | (b3 << 24); } static __inline u32 get_le32(const u8 *p) { return get_le32_split(p[0], p[1], p[2], p[3]); } static __inline void put_le32(u8 *p, u32 v) { p[0] = v; p[1] = v >> 8; p[2] = v >> 16; p[3] = v >> 24; } /* * Craft pseudo header used to calculate the MIC. */ static void michael_mic_hdr(const struct ieee80211_frame *wh0, uint8_t hdr[16]) { const struct ieee80211_frame_addr4 *wh = (const struct ieee80211_frame_addr4 *) wh0; switch (wh->i_fc[1] & IEEE80211_FC1_DIR_MASK) { case IEEE80211_FC1_DIR_NODS: IEEE80211_ADDR_COPY(hdr, wh->i_addr1); /* DA */ IEEE80211_ADDR_COPY(hdr + IEEE80211_ADDR_LEN, wh->i_addr2); break; case IEEE80211_FC1_DIR_TODS: IEEE80211_ADDR_COPY(hdr, wh->i_addr3); /* DA */ IEEE80211_ADDR_COPY(hdr + IEEE80211_ADDR_LEN, wh->i_addr2); break; case IEEE80211_FC1_DIR_FROMDS: IEEE80211_ADDR_COPY(hdr, wh->i_addr1); /* DA */ IEEE80211_ADDR_COPY(hdr + IEEE80211_ADDR_LEN, wh->i_addr3); break; case IEEE80211_FC1_DIR_DSTODS: IEEE80211_ADDR_COPY(hdr, wh->i_addr3); /* DA */ IEEE80211_ADDR_COPY(hdr + IEEE80211_ADDR_LEN, wh->i_addr4); break; } if (wh->i_fc[0] & IEEE80211_FC0_SUBTYPE_QOS) { const struct ieee80211_qosframe *qwh = (const struct ieee80211_qosframe *) wh; hdr[12] = qwh->i_qos[0] & IEEE80211_QOS_TID; } else hdr[12] = 0; hdr[13] = hdr[14] = hdr[15] = 0; /* reserved */ } static void michael_mic(struct tkip_ctx *ctx, const u8 *key, struct mbuf *m, u_int off, size_t data_len, u8 mic[IEEE80211_WEP_MICLEN]) { uint8_t hdr[16]; u32 l, r; const uint8_t *data; u_int space; michael_mic_hdr(mtod(m, struct ieee80211_frame *), hdr); l = get_le32(key); r = get_le32(key + 4); /* Michael MIC pseudo header: DA, SA, 3 x 0, Priority */ l ^= get_le32(hdr); michael_block(l, r); l ^= get_le32(&hdr[4]); michael_block(l, r); l ^= get_le32(&hdr[8]); michael_block(l, r); l ^= get_le32(&hdr[12]); michael_block(l, r); /* first buffer has special handling */ data = mtod(m, const uint8_t *) + off; space = m->m_len - off; for (;;) { if (space > data_len) space = data_len; /* collect 32-bit blocks from current buffer */ while (space >= sizeof(uint32_t)) { l ^= get_le32(data); michael_block(l, r); data += sizeof(uint32_t), space -= sizeof(uint32_t); data_len -= sizeof(uint32_t); } if (data_len < sizeof(uint32_t)) break; m = m->m_next; if (m == NULL) { IASSERT(0, ("out of data, data_len %zu\n", data_len)); break; } if (space != 0) { const uint8_t *data_next; /* * Block straddles buffers, split references. */ data_next = mtod(m, const uint8_t *); IASSERT(m->m_len >= sizeof(uint32_t) - space, ("not enough data in following buffer, " "m_len %u need %zu\n", m->m_len, sizeof(uint32_t) - space)); switch (space) { case 1: l ^= get_le32_split(data[0], data_next[0], data_next[1], data_next[2]); data = data_next + 3; space = m->m_len - 3; break; case 2: l ^= get_le32_split(data[0], data[1], data_next[0], data_next[1]); data = data_next + 2; space = m->m_len - 2; break; case 3: l ^= get_le32_split(data[0], data[1], data[2], data_next[0]); data = data_next + 1; space = m->m_len - 1; break; } michael_block(l, r); data_len -= sizeof(uint32_t); } else { /* * Setup for next buffer. */ data = mtod(m, const uint8_t *); space = m->m_len; } } /* Last block and padding (0x5a, 4..7 x 0) */ switch (data_len) { case 0: l ^= get_le32_split(0x5a, 0, 0, 0); break; case 1: l ^= get_le32_split(data[0], 0x5a, 0, 0); break; case 2: l ^= get_le32_split(data[0], data[1], 0x5a, 0); break; case 3: l ^= get_le32_split(data[0], data[1], data[2], 0x5a); break; } michael_block(l, r); /* l ^= 0; */ michael_block(l, r); put_le32(mic, l); put_le32(mic + 4, r); } static int tkip_encrypt(struct tkip_ctx *ctx, struct ieee80211_key *key, struct mbuf *m, int hdrlen) { struct ieee80211_frame *wh; uint8_t icv[IEEE80211_WEP_CRCLEN]; ctx->tc_ic->ic_stats.is_crypto_tkip++; wh = mtod(m, struct ieee80211_frame *); if (!ctx->tx_phase1_done) { tkip_mixing_phase1(ctx->tx_ttak, key->wk_key, wh->i_addr2, (u32)(key->wk_keytsc >> 16)); ctx->tx_phase1_done = 1; } tkip_mixing_phase2(ctx->tx_rc4key, key->wk_key, ctx->tx_ttak, (u16) key->wk_keytsc); wep_encrypt(ctx->tx_rc4key, m, hdrlen + tkip.ic_header, m->m_pkthdr.len - (hdrlen + tkip.ic_header), icv); (void) m_append(m, IEEE80211_WEP_CRCLEN, icv); /* XXX check return */ key->wk_keytsc++; if ((u16)(key->wk_keytsc) == 0) ctx->tx_phase1_done = 0; return 1; } static int tkip_decrypt(struct tkip_ctx *ctx, struct ieee80211_key *key, struct mbuf *m, int hdrlen) { struct ieee80211_frame *wh; u32 iv32; u16 iv16; ctx->tc_ic->ic_stats.is_crypto_tkip++; wh = mtod(m, struct ieee80211_frame *); /* NB: tkip_decap already verified header and left seq in rx_rsc */ iv16 = (u16) ctx->rx_rsc; iv32 = (u32) (ctx->rx_rsc >> 16); if (iv32 != (u32)(key->wk_keyrsc >> 16) || !ctx->rx_phase1_done) { tkip_mixing_phase1(ctx->rx_ttak, key->wk_key, wh->i_addr2, iv32); ctx->rx_phase1_done = 1; } tkip_mixing_phase2(ctx->rx_rc4key, key->wk_key, ctx->rx_ttak, iv16); /* NB: m is unstripped; deduct headers + ICV to get payload */ if (wep_decrypt(ctx->rx_rc4key, m, hdrlen + tkip.ic_header, m->m_pkthdr.len - (hdrlen + tkip.ic_header + tkip.ic_trailer))) { if (iv32 != (u32)(key->wk_keyrsc >> 16)) { /* Previously cached Phase1 result was already lost, so * it needs to be recalculated for the next packet. */ ctx->rx_phase1_done = 0; } IEEE80211_DPRINTF(ctx->tc_ic, IEEE80211_MSG_CRYPTO, "[%s] TKIP ICV mismatch on decrypt\n", ether_sprintf(wh->i_addr2)); ctx->tc_ic->ic_stats.is_rx_tkipicv++; return 0; } return 1; } IEEE80211_CRYPTO_SETUP(tkip_register) { ieee80211_crypto_register(&tkip); }