crypto/dist/heimdal/lib/hcrypto/pkcs5.c

   1 /*
   2  * Copyright (c) 2006 Kungliga Tekniska Högskolan
   3  * (Royal Institute of Technology, Stockholm, Sweden).
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  *
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  *
  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  * 3. Neither the name of the Institute nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #ifdef HAVE_CONFIG_H
  35 #include <config.h>
  36 #endif
  37
  38 __RCSID("$Heimdal: pkcs5.c 17445 2006-05-05 10:37:46Z lha $"
  39         "$NetBSD$");
  40
  41 #ifdef KRB5
  42 #include <krb5-types.h>
  43 #endif
  44
  45 #include <stdio.h>
  46 #include <stdlib.h>
  47
  48 #include <evp.h>
  49 #include <hmac.h>
  50
  51 #include <roken.h>
  52
  53 int
  54 PKCS5_PBKDF2_HMAC_SHA1(const void * password, size_t password_len,
  55                        const void * salt, size_t salt_len,
  56                        unsigned long iter,
  57                        size_t keylen, void *key)
  58 {
  59     size_t datalen, leftofkey, checksumsize;
  60     char *data, *tmpcksum;
  61     uint32_t keypart;
  62     const EVP_MD *md;
  63     unsigned long i;
  64     int j;
  65     char *p;
  66     unsigned int hmacsize;
  67
  68     md = EVP_sha1();
  69     checksumsize = EVP_MD_size(md);
  70     datalen = salt_len + 4;
  71
  72     tmpcksum = malloc(checksumsize + datalen);
  73     if (tmpcksum == NULL)
  74         return 0;
  75
  76     data = &tmpcksum[checksumsize];
  77
  78     memcpy(data, salt, salt_len);
  79
  80     keypart = 1;
  81     leftofkey = keylen;
  82     p = key;
  83
  84     while (leftofkey) {
  85         int len;
  86
  87         if (leftofkey > checksumsize)
  88             len = checksumsize;
  89         else
  90             len = leftofkey;
  91
  92         data[datalen - 4] = (keypart >> 24) & 0xff;
  93         data[datalen - 3] = (keypart >> 16) & 0xff;
  94         data[datalen - 2] = (keypart >> 8)  & 0xff;
  95         data[datalen - 1] = (keypart)       & 0xff;
  96
  97         HMAC(md, password, password_len, data, datalen,
  98              tmpcksum, &hmacsize);
  99
 100         memcpy(p, tmpcksum, len);
 101         for (i = 1; i < iter; i++) {
 102             HMAC(md, password, password_len, tmpcksum, checksumsize,
 103                  tmpcksum, &hmacsize);
 104
 105             for (j = 0; j < len; j++)
 106                 p[j] ^= tmpcksum[j];
 107         }
 108
 109         p += len;
 110         leftofkey -= len;
 111         keypart++;
 112     }
 113
 114     free(tmpcksum);
 115
 116     return 1;
 117 }