src/external/heimdal/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 #include <config.h>
  35
  36 #ifdef KRB5
  37 #include <krb5-types.h>
  38 #endif
  39
  40 #include <stdio.h>
  41 #include <stdlib.h>
  42
  43 #include <evp.h>
  44 #include <hmac.h>
  45
  46 #include <roken.h>
  47
  48 /**
  49  * As descriped in PKCS5, convert a password, salt, and iteration counter into a crypto key.
  50  *
  51  * @param password Password.
  52  * @param password_len Length of password.
  53  * @param salt Salt
  54  * @param salt_len Length of salt.
  55  * @param iter iteration counter.
  56  * @param keylen the output key length.
  57  * @param key the output key.
  58  *
  59  * @return 1 on success, non 1 on failure.
  60  *
  61  * @ingroup hcrypto_misc
  62  */
  63
  64 int
  65 PKCS5_PBKDF2_HMAC_SHA1(const void * password, size_t password_len,
  66                        const void * salt, size_t salt_len,
  67                        unsigned long iter,
  68                        size_t keylen, void *key)
  69 {
  70     size_t datalen, leftofkey, checksumsize;
  71     char *data, *tmpcksum;
  72     uint32_t keypart;
  73     const EVP_MD *md;
  74     unsigned long i;
  75     int j;
  76     char *p;
  77     unsigned int hmacsize;
  78
  79     md = EVP_sha1();
  80     checksumsize = EVP_MD_size(md);
  81     datalen = salt_len + 4;
  82
  83     tmpcksum = malloc(checksumsize + datalen);
  84     if (tmpcksum == NULL)
  85         return 0;
  86
  87     data = &tmpcksum[checksumsize];
  88
  89     memcpy(data, salt, salt_len);
  90
  91     keypart = 1;
  92     leftofkey = keylen;
  93     p = key;
  94
  95     while (leftofkey) {
  96         int len;
  97
  98         if (leftofkey > checksumsize)
  99             len = checksumsize;
 100         else
 101             len = leftofkey;
 102
 103         data[datalen - 4] = (keypart >> 24) & 0xff;
 104         data[datalen - 3] = (keypart >> 16) & 0xff;
 105         data[datalen - 2] = (keypart >> 8)  & 0xff;
 106         data[datalen - 1] = (keypart)       & 0xff;
 107
 108         HMAC(md, password, password_len, data, datalen,
 109              tmpcksum, &hmacsize);
 110
 111         memcpy(p, tmpcksum, len);
 112         for (i = 1; i < iter; i++) {
 113             HMAC(md, password, password_len, tmpcksum, checksumsize,
 114                  tmpcksum, &hmacsize);
 115
 116             for (j = 0; j < len; j++)
 117                 p[j] ^= tmpcksum[j];
 118         }
 119
 120         p += len;
 121         leftofkey -= len;
 122         keypart++;
 123     }
 124
 125     free(tmpcksum);
 126
 127     return 1;
 128 }