keyexchange/isakmpd-20041012/hash.c

   1 /* $OpenBSD: hash.c,v 1.17 2004/06/14 09:55:41 ho Exp $  */
   2 /* $EOM: hash.c,v 1.10 1999/04/17 23:20:34 niklas Exp $  */
   3
   4 /*
   5  * Copyright (c) 1998 Niels Provos.  All rights reserved.
   6  * Copyright (c) 1999 Niklas Hallqvist.  All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27  */
  28
  29 /*
  30  * This code was written under funding by Ericsson Radio Systems.
  31  */
  32
  33 #include <sys/param.h>
  34 #include <string.h>
  35 #if defined (__APPLE__)
  36 #include <openssl/md5.h>
  37 #include <openssl/sha.h>
  38 #else
  39 #include <md5.h>
  40 #include <sha1.h>
  41 #endif                          /* __APPLE__ */
  42
  43 #include "sysdep.h"
  44
  45 #include "hash.h"
  46 #include "log.h"
  47
  48 void    hmac_init(struct hash *, unsigned char *, unsigned int);
  49 void    hmac_final(unsigned char *, struct hash *);
  50
  51 /* Temporary hash contexts.  */
  52 static union {
  53         MD5_CTX         md5ctx;
  54         SHA1_CTX        sha1ctx;
  55 } Ctx, Ctx2;
  56
  57 /* Temporary hash digest.  */
  58 static unsigned char digest[HASH_MAX];
  59
  60 /* Encapsulation of hash functions.  */
  61
  62 static struct hash hashes[] = {
  63     {
  64         HASH_MD5, 5, MD5_SIZE, (void *)&Ctx.md5ctx, digest,
  65         sizeof(MD5_CTX), (void *)&Ctx2.md5ctx,
  66         (void (*)(void *))MD5Init,
  67         (void (*)(void *, unsigned char *, unsigned int))MD5Update,
  68         (void (*)(unsigned char *, void *))MD5Final,
  69         hmac_init,
  70         hmac_final
  71     }, {
  72         HASH_SHA1, 6, SHA1_SIZE, (void *)&Ctx.sha1ctx, digest,
  73         sizeof(SHA1_CTX), (void *)&Ctx2.sha1ctx,
  74         (void (*)(void *))SHA1Init,
  75         (void (*)(void *, unsigned char *, unsigned int))SHA1Update,
  76         (void (*)(unsigned char *, void *))SHA1Final,
  77         hmac_init,
  78         hmac_final
  79     },
  80 };
  81
  82 struct hash *
  83 hash_get(enum hashes hashtype)
  84 {
  85         size_t  i;
  86
  87         LOG_DBG((LOG_CRYPTO, 60, "hash_get: requested algorithm %d",
  88             hashtype));
  89
  90         for (i = 0; i < sizeof hashes / sizeof hashes[0]; i++)
  91                 if (hashtype == hashes[i].type)
  92                         return &hashes[i];
  93
  94         return 0;
  95 }
  96
  97 /*
  98  * Initial a hash for HMAC usage this requires a special init function.
  99  * ctx, ctx2 hold the contexts, if you want to use the hash object for
 100  * something else in the meantime, be sure to store the contexts somewhere.
 101  */
 102
 103 void
 104 hmac_init(struct hash *hash, unsigned char *okey, unsigned int len)
 105 {
 106         unsigned int    i, blocklen = HMAC_BLOCKLEN;
 107         unsigned char   key[HMAC_BLOCKLEN];
 108
 109         memset(key, 0, blocklen);
 110         if (len > blocklen) {
 111                 /* Truncate key down to blocklen */
 112                 hash->Init(hash->ctx);
 113                 hash->Update(hash->ctx, okey, len);
 114                 hash->Final(key, hash->ctx);
 115         } else {
 116                 memcpy(key, okey, len);
 117         }
 118
 119         /* HMAC I and O pad computation */
 120         for (i = 0; i < blocklen; i++)
 121                 key[i] ^= HMAC_IPAD_VAL;
 122
 123         hash->Init(hash->ctx);
 124         hash->Update(hash->ctx, key, blocklen);
 125
 126         for (i = 0; i < blocklen; i++)
 127                 key[i] ^= (HMAC_IPAD_VAL ^ HMAC_OPAD_VAL);
 128
 129         hash->Init(hash->ctx2);
 130         hash->Update(hash->ctx2, key, blocklen);
 131
 132         memset(key, 0, blocklen);
 133 }
 134
 135 /*
 136  * HMAC Final function
 137  */
 138
 139 void
 140 hmac_final(unsigned char *dgst, struct hash *hash)
 141 {
 142         hash->Final(dgst, hash->ctx);
 143         hash->Update(hash->ctx2, dgst, hash->hashsize);
 144         hash->Final(dgst, hash->ctx2);
 145 }