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     ctx = EVP_MD_CTX_create();
  63     if (ctx == NULL)
  64         return 0;
  65
  66     vlen = EVP_MD_block_size(md);
  67     v = malloc(vlen + 1);
  68     if (v == NULL) {
  69         EVP_MD_CTX_destroy(ctx);
  70         return 0;
  71     }
  72
  73     I = calloc(1, vlen * 2);
  74     if (I == NULL) {
  75         EVP_MD_CTX_destroy(ctx);
  76         free(v);
  77         return 0;
  78     }
  79
  80     if (salt && saltlen > 0) {
  81         for (i = 0; i < vlen; i++)
  82             I[i] = ((unsigned char*)salt)[i % saltlen];
  83         size_I += vlen;
  84     }
  85     /*
  86      * There is a diffrence between the no password string and the
  87      * empty string, in the empty string the UTF16 NUL terminator is
  88      * included into the string.
  89      */
  90     if (key && keylen >= 0) {
  91         for (i = 0; i < vlen / 2; i++) {
  92             I[(i * 2) + size_I] = 0;
  93             I[(i * 2) + size_I + 1] = ((unsigned char*)key)[i % (keylen + 1)];
  94         }
  95         size_I += vlen;
  96     }
  97
  98     while (1) {
  99         BIGNUM *bnB, *bnOne;
 100
 101         if (!EVP_DigestInit_ex(ctx, md, NULL)) {
 102             EVP_MD_CTX_destroy(ctx);
 103             free(I);
 104             free(v);
 105             return 0;
 106         }
 107         for (i = 0; i < vlen; i++)
 108             EVP_DigestUpdate(ctx, &idc, 1);
 109         EVP_DigestUpdate(ctx, I, size_I);
 110         EVP_DigestFinal_ex(ctx, hash, &size);
 111
 112         for (i = 1; i < iteration; i++)
 113             EVP_Digest(hash, size, hash, &size, md, NULL);
 114
 115         memcpy(outp, hash, min(outkeysize, size));
 116         if (outkeysize < size)
 117             break;
 118         outkeysize -= size;
 119         outp += size;
 120
 121         for (i = 0; i < vlen; i++)
 122             v[i] = hash[i % size];
 123
 124         bnB = BN_bin2bn(v, vlen, NULL);
 125         bnOne = BN_new();
 126         BN_set_word(bnOne, 1);
 127
 128         BN_uadd(bnB, bnB, bnOne);
 129
 130         for (i = 0; i < vlen * 2; i += vlen) {
 131             BIGNUM *bnI;
 132             int j;
 133
 134             bnI = BN_bin2bn(I + i, vlen, NULL);
 135
 136             BN_uadd(bnI, bnI, bnB);
 137
 138             j = BN_num_bytes(bnI);
 139             if (j > vlen) {
 140                 assert(j == vlen + 1);
 141                 BN_bn2bin(bnI, v);
 142                 memcpy(I + i, v + 1, vlen);
 143             } else {
 144                 memset(I + i, 0, vlen - j);
 145                 BN_bn2bin(bnI, I + i + vlen - j);
 146             }
 147             BN_free(bnI);
 148         }
 149         BN_free(bnB);
 150         BN_free(bnOne);
 151         size_I = vlen * 2;
 152     }
 153
 154     EVP_MD_CTX_destroy(ctx);
 155     free(I);
 156     free(v);
 157
 158     return 1;
 159 }