/*- * SPDX-License-Identifier: BSD-2-Clause * * Copyright (c) 2002-2008 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. * * 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 /* * IEEE 802.11i AES-CCMP 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 "opt_wlan.h" #include #include #include #include #include #include #include #include #include #include #include #include #define AES_BLOCK_LEN 16 #define CCMP_128_MIC_LEN 8 #define CCMP_256_MIC_LEN 16 struct ccmp_ctx { struct ieee80211vap *cc_vap; /* for diagnostics+statistics */ struct ieee80211com *cc_ic; rijndael_ctx cc_aes; }; static void *ccmp_attach(struct ieee80211vap *, struct ieee80211_key *); static void ccmp_detach(struct ieee80211_key *); static int ccmp_setkey(struct ieee80211_key *); static void ccmp_setiv(struct ieee80211_key *, uint8_t *); static int ccmp_encap(struct ieee80211_key *, struct mbuf *); static int ccmp_decap(struct ieee80211_key *, struct mbuf *, int); static int ccmp_enmic(struct ieee80211_key *, struct mbuf *, int); static int ccmp_demic(struct ieee80211_key *, struct mbuf *, int); static const struct ieee80211_cipher ccmp = { .ic_name = "AES-CCM", .ic_cipher = IEEE80211_CIPHER_AES_CCM, .ic_header = IEEE80211_WEP_IVLEN + IEEE80211_WEP_KIDLEN + IEEE80211_WEP_EXTIVLEN, .ic_trailer = CCMP_128_MIC_LEN, .ic_miclen = 0, .ic_attach = ccmp_attach, .ic_detach = ccmp_detach, .ic_setkey = ccmp_setkey, .ic_setiv = ccmp_setiv, .ic_encap = ccmp_encap, .ic_decap = ccmp_decap, .ic_enmic = ccmp_enmic, .ic_demic = ccmp_demic, }; static const struct ieee80211_cipher ccmp_256 = { .ic_name = "AES-CCM-256", .ic_cipher = IEEE80211_CIPHER_AES_CCM_256, .ic_header = IEEE80211_WEP_IVLEN + IEEE80211_WEP_KIDLEN + IEEE80211_WEP_EXTIVLEN, .ic_trailer = CCMP_256_MIC_LEN, .ic_miclen = 0, .ic_attach = ccmp_attach, .ic_detach = ccmp_detach, .ic_setkey = ccmp_setkey, .ic_setiv = ccmp_setiv, .ic_encap = ccmp_encap, .ic_decap = ccmp_decap, .ic_enmic = ccmp_enmic, .ic_demic = ccmp_demic, }; static int ccmp_encrypt(struct ieee80211_key *, struct mbuf *, int hdrlen); static int ccmp_decrypt(struct ieee80211_key *, u_int64_t pn, struct mbuf *, int hdrlen); /* number of references from net80211 layer */ static int nrefs = 0; static void * ccmp_attach(struct ieee80211vap *vap, struct ieee80211_key *k) { struct ccmp_ctx *ctx; ctx = (struct ccmp_ctx *) IEEE80211_MALLOC(sizeof(struct ccmp_ctx), M_80211_CRYPTO, IEEE80211_M_NOWAIT | IEEE80211_M_ZERO); if (ctx == NULL) { vap->iv_stats.is_crypto_nomem++; return NULL; } ctx->cc_vap = vap; ctx->cc_ic = vap->iv_ic; nrefs++; /* NB: we assume caller locking */ return ctx; } static void ccmp_detach(struct ieee80211_key *k) { struct ccmp_ctx *ctx = k->wk_private; IEEE80211_FREE(ctx, M_80211_CRYPTO); KASSERT(nrefs > 0, ("imbalanced attach/detach")); nrefs--; /* NB: we assume caller locking */ } static int ccmp_get_trailer_len(struct ieee80211_key *k) { return (k->wk_cipher->ic_trailer); } static int ccmp_get_header_len(struct ieee80211_key *k) { return (k->wk_cipher->ic_header); } /** * @brief Return the M parameter to use for CCMP block0 initialisation. * * M is defined as the number of bytes in the authentication * field. * * See RFC3610, Section 2 (CCM Mode Specification) for more * information. * * The MIC size is defined in 802.11-2020 12.5.3 * (CTR with CBC-MAC Protocol (CCMP)). * * CCM-128 - M=8, MIC is 8 octets. * CCM-256 - M=16, MIC is 16 octets. * * @param key ieee80211_key to calculate M for * @retval the number of bytes in the authentication field */ static int ccmp_get_ccm_m(struct ieee80211_key *k) { if (k->wk_cipher->ic_cipher == IEEE80211_CIPHER_AES_CCM) return (8); if (k->wk_cipher->ic_cipher == IEEE80211_CIPHER_AES_CCM_256) return (16); return (8); /* XXX default */ } static int ccmp_setkey(struct ieee80211_key *k) { uint32_t keylen; struct ccmp_ctx *ctx = k->wk_private; switch (k->wk_cipher->ic_cipher) { case IEEE80211_CIPHER_AES_CCM: keylen = 128; break; case IEEE80211_CIPHER_AES_CCM_256: keylen = 256; break; default: IEEE80211_DPRINTF(ctx->cc_vap, IEEE80211_MSG_CRYPTO, "%s: Unexpected cipher (%u)", __func__, k->wk_cipher->ic_cipher); return (0); } if (k->wk_keylen != (keylen/NBBY)) { IEEE80211_DPRINTF(ctx->cc_vap, IEEE80211_MSG_CRYPTO, "%s: Invalid key length %u, expecting %u\n", __func__, k->wk_keylen, keylen/NBBY); return 0; } if (k->wk_flags & IEEE80211_KEY_SWENCRYPT) rijndael_set_key(&ctx->cc_aes, k->wk_key, k->wk_keylen*NBBY); return 1; } static void ccmp_setiv(struct ieee80211_key *k, uint8_t *ivp) { struct ccmp_ctx *ctx = k->wk_private; struct ieee80211vap *vap = ctx->cc_vap; uint8_t keyid; keyid = ieee80211_crypto_get_keyid(vap, k) << 6; k->wk_keytsc++; ivp[0] = k->wk_keytsc >> 0; /* PN0 */ ivp[1] = k->wk_keytsc >> 8; /* PN1 */ ivp[2] = 0; /* Reserved */ ivp[3] = keyid | IEEE80211_WEP_EXTIV; /* KeyID | ExtID */ ivp[4] = k->wk_keytsc >> 16; /* PN2 */ ivp[5] = k->wk_keytsc >> 24; /* PN3 */ ivp[6] = k->wk_keytsc >> 32; /* PN4 */ ivp[7] = k->wk_keytsc >> 40; /* PN5 */ } /* * Add privacy headers appropriate for the specified key. */ static int ccmp_encap(struct ieee80211_key *k, struct mbuf *m) { const struct ieee80211_frame *wh; struct ccmp_ctx *ctx = k->wk_private; struct ieee80211com *ic = ctx->cc_ic; uint8_t *ivp; int hdrlen; int is_mgmt; hdrlen = ieee80211_hdrspace(ic, mtod(m, void *)); wh = mtod(m, const struct ieee80211_frame *); is_mgmt = IEEE80211_IS_MGMT(wh); /* * Check to see if we need to insert IV/MIC. * * Some offload devices don't require the IV to be inserted * as part of the hardware encryption. */ if (is_mgmt && (k->wk_flags & IEEE80211_KEY_NOIVMGT)) return 1; if ((! is_mgmt) && (k->wk_flags & IEEE80211_KEY_NOIV)) return 1; /* * Copy down 802.11 header and add the IV, KeyID, and ExtIV. */ M_PREPEND(m, ccmp_get_header_len(k), IEEE80211_M_NOWAIT); if (m == NULL) return 0; ivp = mtod(m, uint8_t *); ovbcopy(ivp + ccmp_get_header_len(k), ivp, hdrlen); ivp += hdrlen; ccmp_setiv(k, ivp); /* * Finally, do software encrypt if needed. */ if ((k->wk_flags & IEEE80211_KEY_SWENCRYPT) && !ccmp_encrypt(k, m, hdrlen)) return 0; return 1; } /* * Add MIC to the frame as needed. */ static int ccmp_enmic(struct ieee80211_key *k, struct mbuf *m, int force) { 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. The specified key should be correct but * is also verified. */ static int ccmp_decap(struct ieee80211_key *k, struct mbuf *m, int hdrlen) { const struct ieee80211_rx_stats *rxs; struct ccmp_ctx *ctx = k->wk_private; struct ieee80211vap *vap = ctx->cc_vap; struct ieee80211_frame *wh; uint8_t *ivp, tid; uint64_t pn; bool noreplaycheck; rxs = ieee80211_get_rx_params_ptr(m); if ((rxs != NULL) && (rxs->c_pktflags & IEEE80211_RX_F_IV_STRIP) != 0) goto finish; /* * 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_NOTE_MAC(vap, IEEE80211_MSG_CRYPTO, wh->i_addr2, "%s", "missing ExtIV for AES-CCM cipher"); vap->iv_stats.is_rx_ccmpformat++; return 0; } tid = ieee80211_gettid(wh); pn = READ_6(ivp[0], ivp[1], ivp[4], ivp[5], ivp[6], ivp[7]); noreplaycheck = (k->wk_flags & IEEE80211_KEY_NOREPLAY) != 0; noreplaycheck |= (rxs != NULL) && (rxs->c_pktflags & IEEE80211_RX_F_PN_VALIDATED) != 0; if (pn <= k->wk_keyrsc[tid] && !noreplaycheck) { /* * Replay violation. */ ieee80211_notify_replay_failure(vap, wh, k, pn, tid); vap->iv_stats.is_rx_ccmpreplay++; return 0; } /* * 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. Note that for the * latter we leave the header in place for use in the * decryption work. */ if ((k->wk_flags & IEEE80211_KEY_SWDECRYPT) && !ccmp_decrypt(k, pn, m, hdrlen)) return 0; finish: /* * Copy up 802.11 header and strip crypto bits. */ if (! ((rxs != NULL) && (rxs->c_pktflags & IEEE80211_RX_F_IV_STRIP))) { ovbcopy(mtod(m, void *), mtod(m, uint8_t *) + ccmp_get_header_len(k), hdrlen); m_adj(m, ccmp_get_header_len(k)); } if ((rxs == NULL) || (rxs->c_pktflags & IEEE80211_RX_F_MIC_STRIP) == 0) m_adj(m, -ccmp_get_trailer_len(k)); /* * Ok to update rsc now. */ if ((rxs == NULL) || (rxs->c_pktflags & IEEE80211_RX_F_IV_STRIP) == 0) { /* * Do not go backwards in the IEEE80211_KEY_NOREPLAY cases * or in case hardware has checked but frames are arriving * reordered (e.g., LinuxKPI drivers doing RSS which we are * not prepared for at all). */ if (pn > k->wk_keyrsc[tid]) k->wk_keyrsc[tid] = pn; } return 1; } /* * Verify and strip MIC from the frame. */ static int ccmp_demic(struct ieee80211_key *k, struct mbuf *m, int force) { return 1; } static __inline void xor_block(uint8_t *b, const uint8_t *a, size_t len) { int i; for (i = 0; i < len; i++) b[i] ^= a[i]; } /** * @brief Initialise the AES-CCM nonce flag field in the b0 CCMP block. * * The B_0 block is defined in RFC 3610 section 2.2 (Authentication). * b0[0] is the CCM flags field, so the nonce used for B_0 starts at * b0[1]. Amusingly, b0[1] is also flags, but it's the 802.11 AES-CCM * nonce flags field, NOT the CCM flags field. * * The AES-CCM nonce flags field is defined in 802.11-2020 12.5.3.3.4 * (Construct CCM nonce). * * TODO: net80211 currently doesn't support MFP (management frame protection) * and so bit 4 is never set. This routine and ccmp_init_blocks() will * need a pointer to the ieee80211_node or a flag that explicitly states * the frame will be sent w/ MFP encryption / received w/ MFP decryption. * * @param wh the 802.11 header to populate * @param b0 the CCM nonce to update (remembering b0[0] is the CCM * nonce flags, and b0[1] is the AES-CCM nonce flags). */ static void ieee80211_crypto_ccmp_init_nonce_flags(const struct ieee80211_frame *wh, char *b0) { if (IEEE80211_IS_DSTODS(wh)) { /* * 802.11-2020 12.5.33.3.4 (Construct CCM nonce) mentions * that the low four bits of this byte are the "MPDU priority." * This is defined in 5.1.1.2 (Determination of UP) and * 5.1.1.3 (Interpretation of Priority Parameter in MAC * service primitives). * * The former says "The QoS facility supports eight priority * values, referred to as UPs. The values a UP may take are * the integer values from 0 to 7 and are identical to the * 802.11D priority tags." * * The latter specifically calls out that "Priority parameter * and TID subfield values 0 to 7 are interpreted aas UPs for * the MSDUs" .. and " .. TID subfield values 8 to 15 specify * TIDs that are TS identifiers (TSIDs)" which are used for * TSPEC. There's a bunch of extra work to be done with frames * received in TIDs 8..15 with no TSPEC, "then the MSDU shall * be sent with priority parameter set to 0." * * All QoS frames (not just QoS data) have TID fields and * thus priorities. However, the code straight up * copies the 4 bit TID field, rather than a 3 bit MPDU * priority value. For now, as net80211 doesn't specifically * support TSPEC negotiation, this likely never gets checked. * However as part of any future TSPEC work, this will likely * need to be looked at and checked with interoperability * with other stacks. */ if (IEEE80211_IS_QOS_ANY(wh)) { const struct ieee80211_qosframe_addr4 *qwh4 = (const struct ieee80211_qosframe_addr4 *) wh; b0[1] = qwh4->i_qos[0] & 0x0f; /* prio bits */ } else { b0[1] = 0; } } else { if (IEEE80211_IS_QOS_ANY(wh)) { const struct ieee80211_qosframe *qwh = (const struct ieee80211_qosframe *) wh; b0[1] = qwh->i_qos[0] & 0x0f; /* prio bits */ } else { b0[1] = 0; } } /* TODO: populate MFP flag */ } /* * Host AP crypt: host-based CCMP 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 void ccmp_init_blocks(rijndael_ctx *ctx, struct ieee80211_frame *wh, uint32_t m, u_int64_t pn, size_t dlen, uint8_t b0[AES_BLOCK_LEN], uint8_t aad[2 * AES_BLOCK_LEN], uint8_t auth[AES_BLOCK_LEN], uint8_t s0[AES_BLOCK_LEN]) { /* * Map M parameter to encoding * RFC3610, Section 2 (CCM Mode Specification) */ m = (m - 2) / 2; /* CCM Initial Block: * * Flag (Include authentication header, * M=3 or 7 (8 or 16 octet auth field), * L=1 (2-octet Dlen)) * Adata=1 (one or more auth blocks present) * Nonce: 0x00 | A2 | PN * Dlen */ b0[0] = 0x40 | 0x01 | (m << 3); /* Init b0[1] (CCM nonce flags) */ ieee80211_crypto_ccmp_init_nonce_flags(wh, b0); IEEE80211_ADDR_COPY(b0 + 2, wh->i_addr2); b0[8] = pn >> 40; b0[9] = pn >> 32; b0[10] = pn >> 24; b0[11] = pn >> 16; b0[12] = pn >> 8; b0[13] = pn >> 0; b0[14] = (dlen >> 8) & 0xff; b0[15] = dlen & 0xff; /* Init AAD */ (void) ieee80211_crypto_init_aad(wh, aad, 2 * AES_BLOCK_LEN); /* Start with the first block and AAD */ rijndael_encrypt(ctx, b0, auth); xor_block(auth, aad, AES_BLOCK_LEN); rijndael_encrypt(ctx, auth, auth); xor_block(auth, &aad[AES_BLOCK_LEN], AES_BLOCK_LEN); rijndael_encrypt(ctx, auth, auth); b0[0] &= 0x07; b0[14] = b0[15] = 0; rijndael_encrypt(ctx, b0, s0); } #define CCMP_ENCRYPT(_i, _b, _b0, _pos, _e, _len) do { \ /* Authentication */ \ xor_block(_b, _pos, _len); \ rijndael_encrypt(&ctx->cc_aes, _b, _b); \ /* Encryption, with counter */ \ _b0[14] = (_i >> 8) & 0xff; \ _b0[15] = _i & 0xff; \ rijndael_encrypt(&ctx->cc_aes, _b0, _e); \ xor_block(_pos, _e, _len); \ } while (0) static int ccmp_encrypt(struct ieee80211_key *key, struct mbuf *m0, int hdrlen) { struct ccmp_ctx *ctx = key->wk_private; struct ieee80211_frame *wh; struct mbuf *m = m0; int data_len, i, space; uint8_t aad[2 * AES_BLOCK_LEN], b0[AES_BLOCK_LEN], b[AES_BLOCK_LEN], e[AES_BLOCK_LEN], s0[AES_BLOCK_LEN]; uint8_t *pos; ctx->cc_vap->iv_stats.is_crypto_ccmp++; wh = mtod(m, struct ieee80211_frame *); data_len = m->m_pkthdr.len - (hdrlen + ccmp_get_header_len(key)); ccmp_init_blocks(&ctx->cc_aes, wh, ccmp_get_ccm_m(key), key->wk_keytsc, data_len, b0, aad, b, s0); i = 1; pos = mtod(m, uint8_t *) + hdrlen + ccmp_get_header_len(key); /* NB: assumes header is entirely in first mbuf */ space = m->m_len - (hdrlen + ccmp_get_header_len(key)); for (;;) { if (space > data_len) space = data_len; /* * Do full blocks. */ while (space >= AES_BLOCK_LEN) { CCMP_ENCRYPT(i, b, b0, pos, e, AES_BLOCK_LEN); pos += AES_BLOCK_LEN, space -= AES_BLOCK_LEN; data_len -= AES_BLOCK_LEN; i++; } if (data_len <= 0) /* no more data */ break; m = m->m_next; if (m == NULL) { /* last buffer */ if (space != 0) { /* * Short last block. */ CCMP_ENCRYPT(i, b, b0, pos, e, space); } break; } if (space != 0) { uint8_t *pos_next; int space_next; int len, dl, sp; struct mbuf *n; /* * Block straddles one or more mbufs, gather data * into the block buffer b, apply the cipher, then * scatter the results back into the mbuf chain. * The buffer will automatically get space bytes * of data at offset 0 copied in+out by the * CCMP_ENCRYPT request so we must take care of * the remaining data. */ n = m; dl = data_len; sp = space; for (;;) { pos_next = mtod(n, uint8_t *); len = min(dl, AES_BLOCK_LEN); space_next = len > sp ? len - sp : 0; if (n->m_len >= space_next) { /* * This mbuf has enough data; just grab * what we need and stop. */ xor_block(b+sp, pos_next, space_next); break; } /* * This mbuf's contents are insufficient, * take 'em all and prepare to advance to * the next mbuf. */ xor_block(b+sp, pos_next, n->m_len); sp += n->m_len, dl -= n->m_len; n = n->m_next; if (n == NULL) break; } CCMP_ENCRYPT(i, b, b0, pos, e, space); /* NB: just like above, but scatter data to mbufs */ dl = data_len; sp = space; for (;;) { pos_next = mtod(m, uint8_t *); len = min(dl, AES_BLOCK_LEN); space_next = len > sp ? len - sp : 0; if (m->m_len >= space_next) { xor_block(pos_next, e+sp, space_next); break; } xor_block(pos_next, e+sp, m->m_len); sp += m->m_len, dl -= m->m_len; m = m->m_next; if (m == NULL) goto done; } /* * Do bookkeeping. m now points to the last mbuf * we grabbed data from. We know we consumed a * full block of data as otherwise we'd have hit * the end of the mbuf chain, so deduct from data_len. * Otherwise advance the block number (i) and setup * pos+space to reflect contents of the new mbuf. */ data_len -= AES_BLOCK_LEN; i++; pos = pos_next + space_next; space = m->m_len - space_next; } else { /* * Setup for next buffer. */ pos = mtod(m, uint8_t *); space = m->m_len; } } done: /* tack on MIC */ xor_block(b, s0, ccmp_get_trailer_len(key)); return m_append(m0, ccmp_get_trailer_len(key), b); } #undef CCMP_ENCRYPT #define CCMP_DECRYPT(_i, _b, _b0, _pos, _a, _len) do { \ /* Decrypt, with counter */ \ _b0[14] = (_i >> 8) & 0xff; \ _b0[15] = _i & 0xff; \ rijndael_encrypt(&ctx->cc_aes, _b0, _b); \ xor_block(_pos, _b, _len); \ /* Authentication */ \ xor_block(_a, _pos, _len); \ rijndael_encrypt(&ctx->cc_aes, _a, _a); \ } while (0) static int ccmp_decrypt(struct ieee80211_key *key, u_int64_t pn, struct mbuf *m, int hdrlen) { const struct ieee80211_rx_stats *rxs; struct ccmp_ctx *ctx = key->wk_private; struct ieee80211vap *vap = ctx->cc_vap; struct ieee80211_frame *wh; uint8_t aad[2 * AES_BLOCK_LEN]; uint8_t b0[AES_BLOCK_LEN], b[AES_BLOCK_LEN], a[AES_BLOCK_LEN]; uint8_t mic[AES_BLOCK_LEN]; size_t data_len; int i; uint8_t *pos; u_int space; rxs = ieee80211_get_rx_params_ptr(m); if ((rxs != NULL) && (rxs->c_pktflags & IEEE80211_RX_F_DECRYPTED) != 0) return (1); ctx->cc_vap->iv_stats.is_crypto_ccmp++; wh = mtod(m, struct ieee80211_frame *); data_len = m->m_pkthdr.len - (hdrlen + ccmp_get_header_len(key) + ccmp_get_trailer_len(key)); ccmp_init_blocks(&ctx->cc_aes, wh, ccmp_get_ccm_m(key), pn, data_len, b0, aad, a, b); m_copydata(m, m->m_pkthdr.len - ccmp_get_trailer_len(key), ccmp_get_trailer_len(key), mic); xor_block(mic, b, ccmp_get_trailer_len(key)); i = 1; pos = mtod(m, uint8_t *) + hdrlen + ccmp_get_header_len(key); space = m->m_len - (hdrlen + ccmp_get_header_len(key)); for (;;) { if (space > data_len) space = data_len; while (space >= AES_BLOCK_LEN) { CCMP_DECRYPT(i, b, b0, pos, a, AES_BLOCK_LEN); pos += AES_BLOCK_LEN, space -= AES_BLOCK_LEN; data_len -= AES_BLOCK_LEN; i++; } if (data_len <= 0) /* no more data */ break; m = m->m_next; if (m == NULL) { /* last buffer */ if (space != 0) /* short last block */ CCMP_DECRYPT(i, b, b0, pos, a, space); break; } if (space != 0) { uint8_t *pos_next; u_int space_next; u_int len; /* * Block straddles buffers, split references. We * do not handle splits that require >2 buffers * since rx'd frames are never badly fragmented * because drivers typically recv in clusters. */ pos_next = mtod(m, uint8_t *); len = min(data_len, AES_BLOCK_LEN); space_next = len > space ? len - space : 0; KASSERT(m->m_len >= space_next, ("not enough data in following buffer, " "m_len %u need %u\n", m->m_len, space_next)); xor_block(b+space, pos_next, space_next); CCMP_DECRYPT(i, b, b0, pos, a, space); xor_block(pos_next, b+space, space_next); data_len -= len; i++; pos = pos_next + space_next; space = m->m_len - space_next; } else { /* * Setup for next buffer. */ pos = mtod(m, uint8_t *); space = m->m_len; } } /* * If the MIC was stripped by HW/driver we are done. */ if ((rxs != NULL) && (rxs->c_pktflags & IEEE80211_RX_F_MIC_STRIP) != 0) return (1); if (memcmp(mic, a, ccmp_get_trailer_len(key)) != 0) { IEEE80211_NOTE_MAC(vap, IEEE80211_MSG_CRYPTO, wh->i_addr2, "%s", "AES-CCM decrypt failed; MIC mismatch"); vap->iv_stats.is_rx_ccmpmic++; return 0; } return 1; } #undef CCMP_DECRYPT /* * Module glue. */ IEEE80211_CRYPTO_MODULE(ccmp, 1); IEEE80211_CRYPTO_MODULE_ADD(ccmp_256);