460 lines
10 KiB
C
460 lines
10 KiB
C
/* $NetBSD: esp_aesctr.c,v 1.7 2007/05/23 17:15:00 christos Exp $ */
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/* $KAME: esp_aesctr.c,v 1.2 2003/07/20 00:29:37 itojun Exp $ */
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/*
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* Copyright (C) 1995, 1996, 1997, 1998 and 2003 WIDE Project.
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Neither the name of the project nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#include <sys/cdefs.h>
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__KERNEL_RCSID(0, "$NetBSD: esp_aesctr.c,v 1.7 2007/05/23 17:15:00 christos Exp $");
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/socket.h>
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#include <sys/queue.h>
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#include <sys/syslog.h>
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#include <sys/mbuf.h>
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#include <net/if.h>
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#include <net/route.h>
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#include <netinet/in.h>
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#include <netinet6/ipsec.h>
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#include <netinet6/esp.h>
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#include <netinet6/esp_aesctr.h>
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#include <netkey/key.h>
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#include <crypto/rijndael/rijndael.h>
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#include <net/net_osdep.h>
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#define AES_BLOCKSIZE 16
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#define NONCESIZE 4
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union cblock {
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struct {
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u_int8_t nonce[4];
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u_int8_t iv[8];
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u_int32_t ctr;
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} v __attribute__((__packed__));
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u_int8_t cblock[16];
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};
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typedef struct {
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u_int32_t r_ek[(RIJNDAEL_MAXNR+1)*4];
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int r_nr; /* key-length-dependent number of rounds */
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} aesctr_ctx;
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int
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esp_aesctr_mature(struct secasvar *sav)
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{
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int keylen;
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const struct esp_algorithm *algo;
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algo = esp_algorithm_lookup(sav->alg_enc);
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if (!algo) {
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ipseclog((LOG_ERR,
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"esp_aeesctr_mature %s: unsupported algorithm.\n",
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algo->name));
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return 1;
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}
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keylen = sav->key_enc->sadb_key_bits;
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if (keylen < algo->keymin || algo->keymax < keylen) {
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ipseclog((LOG_ERR,
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"esp_aesctr_mature %s: invalid key length %d.\n",
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algo->name, sav->key_enc->sadb_key_bits));
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return 1;
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}
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/* rijndael key + nonce */
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if (!(keylen == 128 + 32 || keylen == 192 + 32 || keylen == 256 + 32)) {
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ipseclog((LOG_ERR,
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"esp_aesctr_mature %s: invalid key length %d.\n",
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algo->name, keylen));
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return 1;
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}
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return 0;
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}
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size_t
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esp_aesctr_schedlen(const struct esp_algorithm *algo)
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{
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return sizeof(aesctr_ctx);
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}
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int
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esp_aesctr_schedule(const struct esp_algorithm *algo,
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struct secasvar *sav)
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{
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aesctr_ctx *ctx;
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int keylen;
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/* SA key = AES key + nonce */
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keylen = _KEYLEN(sav->key_enc) * 8 - NONCESIZE * 8;
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ctx = (aesctr_ctx *)sav->sched;
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if ((ctx->r_nr = rijndaelKeySetupEnc(ctx->r_ek,
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(char *)_KEYBUF(sav->key_enc), keylen)) == 0)
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return -1;
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return 0;
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}
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int
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esp_aesctr_decrypt(struct mbuf *m, size_t off, struct secasvar *sav,
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const struct esp_algorithm *algo, int ivlen)
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{
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struct mbuf *s;
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struct mbuf *d, *d0 = NULL, *dp;
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int soff, doff; /* offset from the head of chain, to head of this mbuf */
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int sn, dn; /* offset from the head of the mbuf, to meat */
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size_t ivoff, bodyoff;
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union cblock cblock;
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u_int8_t keystream[AES_BLOCKSIZE], *nonce;
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u_int32_t ctr;
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u_int8_t *ivp;
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u_int8_t sbuf[AES_BLOCKSIZE], *sp, *dst;
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struct mbuf *scut;
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int scutoff;
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int i;
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int blocklen;
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aesctr_ctx *ctx;
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if (ivlen != sav->ivlen) {
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ipseclog((LOG_ERR, "esp_aesctr_decrypt %s: "
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"unsupported ivlen %d\n", algo->name, ivlen));
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goto fail;
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}
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/* assumes blocklen == padbound */
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blocklen = algo->padbound;
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ivoff = off + sizeof(struct newesp);
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bodyoff = off + sizeof(struct newesp) + ivlen;
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/* setup counter block */
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nonce = _KEYBUF(sav->key_enc) + _KEYLEN(sav->key_enc) - NONCESIZE;
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bcopy(nonce, cblock.v.nonce, NONCESIZE);
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m_copydata(m, ivoff, ivlen, cblock.v.iv);
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ctr = 1;
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if (m->m_pkthdr.len < bodyoff) {
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ipseclog((LOG_ERR, "esp_aesctr_decrypt %s: bad len %d/%lu\n",
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algo->name, m->m_pkthdr.len, (unsigned long)bodyoff));
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goto fail;
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}
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if ((m->m_pkthdr.len - bodyoff) % blocklen) {
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ipseclog((LOG_ERR, "esp_aesctr_decrypt %s: "
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"payload length must be multiple of %d\n",
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algo->name, blocklen));
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goto fail;
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}
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s = m;
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d = d0 = dp = NULL;
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soff = doff = sn = dn = 0;
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ivp = sp = NULL;
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/* skip bodyoff */
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while (soff < bodyoff) {
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if (soff + s->m_len > bodyoff) {
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sn = bodyoff - soff;
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break;
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}
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soff += s->m_len;
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s = s->m_next;
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}
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scut = s;
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scutoff = sn;
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/* skip over empty mbuf */
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while (s && s->m_len == 0)
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s = s->m_next;
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while (soff < m->m_pkthdr.len) {
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/* source */
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if (sn + blocklen <= s->m_len) {
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/* body is continuous */
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sp = mtod(s, u_int8_t *) + sn;
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} else {
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/* body is non-continuous */
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m_copydata(s, sn, blocklen, (void *)sbuf);
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sp = sbuf;
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}
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/* destination */
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if (!d || dn + blocklen > d->m_len) {
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if (d)
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dp = d;
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MGET(d, M_DONTWAIT, MT_DATA);
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i = m->m_pkthdr.len - (soff + sn);
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if (d && i > MLEN) {
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MCLGET(d, M_DONTWAIT);
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if ((d->m_flags & M_EXT) == 0) {
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m_free(d);
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d = NULL;
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}
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}
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if (!d) {
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goto nomem;
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}
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if (!d0)
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d0 = d;
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if (dp)
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dp->m_next = d;
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d->m_len = 0;
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d->m_len = (M_TRAILINGSPACE(d) / blocklen) * blocklen;
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if (d->m_len > i)
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d->m_len = i;
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dn = 0;
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}
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/* put counter into counter block */
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cblock.v.ctr = htonl(ctr);
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/* setup keystream */
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ctx = (aesctr_ctx *)sav->sched;
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rijndaelEncrypt(ctx->r_ek, ctx->r_nr, cblock.cblock, keystream);
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bcopy(sp, mtod(d, u_int8_t *) + dn, blocklen);
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dst = mtod(d, u_int8_t *) + dn;
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for (i = 0; i < blocklen; i++)
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dst[i] ^= keystream[i];
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ctr++;
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sn += blocklen;
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dn += blocklen;
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/* find the next source block */
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while (s && sn >= s->m_len) {
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sn -= s->m_len;
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soff += s->m_len;
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s = s->m_next;
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}
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/* skip over empty mbuf */
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while (s && s->m_len == 0)
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s = s->m_next;
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}
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m_freem(scut->m_next);
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scut->m_len = scutoff;
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scut->m_next = d0;
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/* just in case */
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bzero(&cblock, sizeof(cblock));
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bzero(keystream, sizeof(keystream));
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return 0;
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fail:
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m_freem(m);
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if (d0)
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m_freem(d0);
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return EINVAL;
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nomem:
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m_freem(m);
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if (d0)
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m_freem(d0);
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return ENOBUFS;
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}
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int
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esp_aesctr_encrypt(
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struct mbuf *m,
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size_t off,
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size_t plen,
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struct secasvar *sav,
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const struct esp_algorithm *algo,
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int ivlen
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)
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{
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struct mbuf *s;
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struct mbuf *d, *d0, *dp;
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int soff, doff; /* offset from the head of chain, to head of this mbuf */
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int sn, dn; /* offset from the head of the mbuf, to meat */
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size_t ivoff, bodyoff;
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union cblock cblock;
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u_int8_t keystream[AES_BLOCKSIZE], *nonce;
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u_int32_t ctr;
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u_int8_t sbuf[AES_BLOCKSIZE], *sp, *dst;
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struct mbuf *scut;
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int scutoff;
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int i;
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int blocklen;
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aesctr_ctx *ctx;
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if (ivlen != sav->ivlen) {
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ipseclog((LOG_ERR, "esp_aesctr_encrypt %s: "
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"unsupported ivlen %d\n", algo->name, ivlen));
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m_freem(m);
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return EINVAL;
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}
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/* assumes blocklen == padbound */
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blocklen = algo->padbound;
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ivoff = off + sizeof(struct newesp);
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bodyoff = off + sizeof(struct newesp) + ivlen;
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/* put iv into the packet. */
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/* maybe it is better to overwrite dest, not source */
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m_copyback(m, ivoff, ivlen, sav->iv);
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/* setup counter block */
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nonce = _KEYBUF(sav->key_enc) + _KEYLEN(sav->key_enc) - NONCESIZE;
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bcopy(nonce, cblock.v.nonce, NONCESIZE);
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m_copydata(m, ivoff, ivlen, cblock.v.iv);
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ctr = 1;
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if (m->m_pkthdr.len < bodyoff) {
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ipseclog((LOG_ERR, "esp_aesctr_encrypt %s: bad len %d/%lu\n",
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algo->name, m->m_pkthdr.len, (unsigned long)bodyoff));
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m_freem(m);
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return EINVAL;
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}
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if ((m->m_pkthdr.len - bodyoff) % blocklen) {
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ipseclog((LOG_ERR, "esp_aesctr_encrypt %s: "
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"payload length must be multiple of %lu\n",
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algo->name, (unsigned long)algo->padbound));
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m_freem(m);
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return EINVAL;
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}
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s = m;
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d = d0 = dp = NULL;
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soff = doff = sn = dn = 0;
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sp = NULL;
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/* skip bodyoff */
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while (soff < bodyoff) {
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if (soff + s->m_len > bodyoff) {
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sn = bodyoff - soff;
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break;
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}
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soff += s->m_len;
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s = s->m_next;
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}
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scut = s;
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scutoff = sn;
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/* skip over empty mbuf */
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while (s && s->m_len == 0)
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s = s->m_next;
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while (soff < m->m_pkthdr.len) {
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/* source */
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if (sn + blocklen <= s->m_len) {
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/* body is continuous */
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sp = mtod(s, u_int8_t *) + sn;
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} else {
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/* body is non-continuous */
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m_copydata(s, sn, blocklen, (void *)sbuf);
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sp = sbuf;
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}
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/* destination */
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if (!d || dn + blocklen > d->m_len) {
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if (d)
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dp = d;
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MGET(d, M_DONTWAIT, MT_DATA);
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i = m->m_pkthdr.len - (soff + sn);
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if (d && i > MLEN) {
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MCLGET(d, M_DONTWAIT);
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if ((d->m_flags & M_EXT) == 0) {
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m_free(d);
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d = NULL;
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}
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}
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if (!d) {
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m_freem(m);
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if (d0)
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m_freem(d0);
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return ENOBUFS;
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}
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if (!d0)
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d0 = d;
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if (dp)
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dp->m_next = d;
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d->m_len = 0;
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d->m_len = (M_TRAILINGSPACE(d) / blocklen) * blocklen;
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if (d->m_len > i)
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d->m_len = i;
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dn = 0;
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}
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/* put counter into counter block */
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cblock.v.ctr = htonl(ctr);
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/* setup keystream */
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ctx = (aesctr_ctx *)sav->sched;
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rijndaelEncrypt(ctx->r_ek, ctx->r_nr, cblock.cblock, keystream);
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bcopy(sp, mtod(d, u_int8_t *) + dn, blocklen);
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dst = mtod(d, u_int8_t *) + dn;
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for (i = 0; i < blocklen; i++)
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dst[i] ^= keystream[i];
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ctr++;
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sn += blocklen;
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dn += blocklen;
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/* find the next source block */
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while (s && sn >= s->m_len) {
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sn -= s->m_len;
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soff += s->m_len;
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s = s->m_next;
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}
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/* skip over empty mbuf */
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while (s && s->m_len == 0)
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s = s->m_next;
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}
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m_freem(scut->m_next);
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scut->m_len = scutoff;
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scut->m_next = d0;
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/* just in case */
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bzero(&cblock, sizeof(cblock));
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bzero(keystream, sizeof(keystream));
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key_sa_stir_iv(sav);
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return 0;
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}
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