lib/hcrypto/pkcs12.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("$Id$");
  39
  40 #include <stdio.h>
  41 #include <stdlib.h>
  42 #include <assert.h>
  43
  44 #include <pkcs12.h>
  45 #include <bn.h>
  46
  47 #include <roken.h>
  48
  49 int
  50 PKCS12_key_gen(const void *key, size_t keylen,
  51                const void *salt, size_t saltlen,
  52                int id, int iteration, size_t outkeysize,
  53                void *out, const EVP_MD *md)
  54 {
  55     unsigned char *v, *I, hash[EVP_MAX_MD_SIZE];
  56     unsigned int size, size_I = 0;
  57     unsigned char idc = id;
  58     EVP_MD_CTX ctx;
  59     unsigned char *outp = out;
  60     int i, vlen;
  61
  62     EVP_MD_CTX_init(&ctx);
  63
  64     vlen = EVP_MD_block_size(md);
  65     v = malloc(vlen + 1);
  66     if (v == NULL)
  67         return 0;
  68
  69     I = calloc(1, vlen * 2);
  70     if (I == NULL) {
  71         free(v);
  72         return 0;
  73     }
  74
  75     if (salt && saltlen > 0) {
  76         for (i = 0; i < vlen; i++)
  77             I[i] = ((unsigned char*)salt)[i % saltlen];
  78         size_I += vlen;
  79     }
  80     /*
  81      * There is a diffrence between the no password string and the
  82      * empty string, in the empty string the UTF16 NUL terminator is
  83      * included into the string.
  84      */
  85     if (key && keylen >= 0) {
  86         for (i = 0; i < vlen / 2; i++) {
  87             I[(i * 2) + size_I] = 0;
  88             I[(i * 2) + size_I + 1] = ((unsigned char*)key)[i % (keylen + 1)];
  89         }
  90         size_I += vlen;
  91     }
  92
  93     while (1) {
  94         BIGNUM *bnB, *bnOne;
  95
  96         if (!EVP_DigestInit_ex(&ctx, md, NULL)) {
  97             free(I);
  98             free(v);
  99             return 0;
 100         }
 101         for (i = 0; i < vlen; i++)
 102             EVP_DigestUpdate(&ctx, &idc, 1);
 103         EVP_DigestUpdate(&ctx, I, size_I);
 104         EVP_DigestFinal_ex(&ctx, hash, &size);
 105
 106         for (i = 1; i < iteration; i++)
 107             EVP_Digest(hash, size, hash, &size, md, NULL);
 108
 109         memcpy(outp, hash, min(outkeysize, size));
 110         if (outkeysize < size)
 111             break;
 112         outkeysize -= size;
 113         outp += size;
 114
 115         for (i = 0; i < vlen; i++)
 116             v[i] = hash[i % size];
 117
 118         bnB = BN_bin2bn(v, vlen, NULL);
 119         bnOne = BN_new();
 120         BN_set_word(bnOne, 1);
 121
 122         BN_uadd(bnB, bnB, bnOne);
 123
 124         for (i = 0; i < vlen * 2; i += vlen) {
 125             BIGNUM *bnI;
 126             int j;
 127
 128             bnI = BN_bin2bn(I + i, vlen, NULL);
 129
 130             BN_uadd(bnI, bnI, bnB);
 131
 132             j = BN_num_bytes(bnI);
 133             if (j > vlen) {
 134                 assert(j == vlen + 1);
 135                 BN_bn2bin(bnI, v);
 136                 memcpy(I + i, v + 1, vlen);
 137             } else {
 138                 memset(I + i, 0, vlen - j);
 139                 BN_bn2bin(bnI, I + i + vlen - j);
 140             }
 141             BN_free(bnI);
 142         }
 143         BN_free(bnB);
 144         BN_free(bnOne);
 145         size_I = vlen * 2;
 146     }
 147
 148     EVP_MD_CTX_cleanup(&ctx);
 149     free(I);
 150     free(v);
 151
 152     return 1;
 153 }