mirror of git://anongit.mindrot.org/openssh.git
126 lines
3.5 KiB
C
126 lines
3.5 KiB
C
/* $OpenBSD: mac.c,v 1.12 2006/08/03 03:34:42 deraadt Exp $ */
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/*
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* Copyright (c) 2001 Markus Friedl. 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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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#include "includes.h"
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#include <sys/types.h>
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#include <openssl/hmac.h>
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#include <stdarg.h>
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#include <string.h>
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#include <signal.h>
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#include "xmalloc.h"
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#include "log.h"
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#include "cipher.h"
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#include "buffer.h"
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#include "key.h"
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#include "kex.h"
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#include "mac.h"
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#include "misc.h"
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struct {
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char *name;
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const EVP_MD * (*mdfunc)(void);
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int truncatebits; /* truncate digest if != 0 */
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} macs[] = {
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{ "hmac-sha1", EVP_sha1, 0, },
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{ "hmac-sha1-96", EVP_sha1, 96 },
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{ "hmac-md5", EVP_md5, 0 },
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{ "hmac-md5-96", EVP_md5, 96 },
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{ "hmac-ripemd160", EVP_ripemd160, 0 },
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{ "hmac-ripemd160@openssh.com", EVP_ripemd160, 0 },
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{ NULL, NULL, 0 }
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};
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int
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mac_init(Mac *mac, char *name)
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{
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int i, evp_len;
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for (i = 0; macs[i].name; i++) {
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if (strcmp(name, macs[i].name) == 0) {
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if (mac != NULL) {
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mac->md = (*macs[i].mdfunc)();
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if ((evp_len = EVP_MD_size(mac->md)) <= 0)
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fatal("mac %s len %d", name, evp_len);
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mac->key_len = mac->mac_len = (u_int)evp_len;
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if (macs[i].truncatebits != 0)
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mac->mac_len = macs[i].truncatebits/8;
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}
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debug2("mac_init: found %s", name);
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return (0);
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}
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}
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debug2("mac_init: unknown %s", name);
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return (-1);
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}
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u_char *
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mac_compute(Mac *mac, u_int32_t seqno, u_char *data, int datalen)
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{
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HMAC_CTX c;
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static u_char m[EVP_MAX_MD_SIZE];
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u_char b[4];
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if (mac->key == NULL)
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fatal("mac_compute: no key");
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if (mac->mac_len > sizeof(m))
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fatal("mac_compute: mac too long");
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HMAC_Init(&c, mac->key, mac->key_len, mac->md);
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put_u32(b, seqno);
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HMAC_Update(&c, b, sizeof(b));
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HMAC_Update(&c, data, datalen);
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HMAC_Final(&c, m, NULL);
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HMAC_cleanup(&c);
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return (m);
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}
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/* XXX copied from ciphers_valid */
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#define MAC_SEP ","
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int
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mac_valid(const char *names)
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{
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char *maclist, *cp, *p;
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if (names == NULL || strcmp(names, "") == 0)
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return (0);
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maclist = cp = xstrdup(names);
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for ((p = strsep(&cp, MAC_SEP)); p && *p != '\0';
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(p = strsep(&cp, MAC_SEP))) {
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if (mac_init(NULL, p) < 0) {
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debug("bad mac %s [%s]", p, names);
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xfree(maclist);
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return (0);
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} else {
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debug3("mac ok: %s [%s]", p, names);
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}
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}
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debug3("macs ok: [%s]", names);
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xfree(maclist);
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return (1);
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}
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