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

   1 /*      $NetBSD: pkcs5.c,v 1.1.1.1 2011/04/13 18:14:50 elric Exp $      */
   2
   3 /*
   4  * Copyright (c) 2006 Kungliga Tekniska Högskolan
   5  * (Royal Institute of Technology, Stockholm, Sweden).
   6  * 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  *
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  *
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  *
  19  * 3. Neither the name of the Institute nor the names of its contributors
  20  *    may be used to endorse or promote products derived from this software
  21  *    without specific prior written permission.
  22  *
  23  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
  24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
  27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  33  * SUCH DAMAGE.
  34  */
  35
  36 #include <config.h>
  37
  38 #ifdef KRB5
  39 #include <krb5/krb5-types.h>
  40 #endif
  41
  42 #include <stdio.h>
  43 #include <stdlib.h>
  44
  45 #include <evp.h>
  46 #include <hmac.h>
  47
  48 #include <krb5/roken.h>
  49
  50 /**
  51  * As descriped in PKCS5, convert a password, salt, and iteration counter into a crypto key.
  52  *
  53  * @param password Password.
  54  * @param password_len Length of password.
  55  * @param salt Salt
  56  * @param salt_len Length of salt.
  57  * @param iter iteration counter.
  58  * @param keylen the output key length.
  59  * @param key the output key.
  60  *
  61  * @return 1 on success, non 1 on failure.
  62  *
  63  * @ingroup hcrypto_misc
  64  */
  65
  66 int
  67 PKCS5_PBKDF2_HMAC_SHA1(const void * password, size_t password_len,
  68                        const void * salt, size_t salt_len,
  69                        unsigned long iter,
  70                        size_t keylen, void *key)
  71 {
  72     size_t datalen, leftofkey, checksumsize;
  73     char *data, *tmpcksum;
  74     uint32_t keypart;
  75     const EVP_MD *md;
  76     unsigned long i;
  77     int j;
  78     char *p;
  79     unsigned int hmacsize;
  80
  81     md = EVP_sha1();
  82     checksumsize = EVP_MD_size(md);
  83     datalen = salt_len + 4;
  84
  85     tmpcksum = malloc(checksumsize + datalen);
  86     if (tmpcksum == NULL)
  87         return 0;
  88
  89     data = &tmpcksum[checksumsize];
  90
  91     memcpy(data, salt, salt_len);
  92
  93     keypart = 1;
  94     leftofkey = keylen;
  95     p = key;
  96
  97     while (leftofkey) {
  98         int len;
  99
 100         if (leftofkey > checksumsize)
 101             len = checksumsize;
 102         else
 103             len = leftofkey;
 104
 105         data[datalen - 4] = (keypart >> 24) & 0xff;
 106         data[datalen - 3] = (keypart >> 16) & 0xff;
 107         data[datalen - 2] = (keypart >> 8)  & 0xff;
 108         data[datalen - 1] = (keypart)       & 0xff;
 109
 110         HMAC(md, password, password_len, data, datalen,
 111              tmpcksum, &hmacsize);
 112
 113         memcpy(p, tmpcksum, len);
 114         for (i = 1; i < iter; i++) {
 115             HMAC(md, password, password_len, tmpcksum, checksumsize,
 116                  tmpcksum, &hmacsize);
 117
 118             for (j = 0; j < len; j++)
 119                 p[j] ^= tmpcksum[j];
 120         }
 121
 122         p += len;
 123         leftofkey -= len;
 124         keypart++;
 125     }
 126
 127     free(tmpcksum);
 128
 129     return 1;
 130 }