crypto/external/bsd/heimdal/dist/lib/krb5/crypto-evp.c

   1 /*      $NetBSD: crypto-evp.c,v 1.1.1.2 2014/04/24 12:45:49 pettai Exp $        */
   2
   3 /*
   4  * Copyright (c) 1997 - 2008 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 "krb5_locl.h"
  37
  38 void
  39 _krb5_evp_schedule(krb5_context context,
  40                    struct _krb5_key_type *kt,
  41                    struct _krb5_key_data *kd)
  42 {
  43     struct _krb5_evp_schedule *key = kd->schedule->data;
  44     const EVP_CIPHER *c = (*kt->evp)();
  45
  46     EVP_CIPHER_CTX_init(&key->ectx);
  47     EVP_CIPHER_CTX_init(&key->dctx);
  48
  49     EVP_CipherInit_ex(&key->ectx, c, NULL, kd->key->keyvalue.data, NULL, 1);
  50     EVP_CipherInit_ex(&key->dctx, c, NULL, kd->key->keyvalue.data, NULL, 0);
  51 }
  52
  53 void
  54 _krb5_evp_cleanup(krb5_context context, struct _krb5_key_data *kd)
  55 {
  56     struct _krb5_evp_schedule *key = kd->schedule->data;
  57     EVP_CIPHER_CTX_cleanup(&key->ectx);
  58     EVP_CIPHER_CTX_cleanup(&key->dctx);
  59 }
  60
  61 krb5_error_code
  62 _krb5_evp_encrypt(krb5_context context,
  63                 struct _krb5_key_data *key,
  64                 void *data,
  65                 size_t len,
  66                 krb5_boolean encryptp,
  67                 int usage,
  68                 void *ivec)
  69 {
  70     struct _krb5_evp_schedule *ctx = key->schedule->data;
  71     EVP_CIPHER_CTX *c;
  72     c = encryptp ? &ctx->ectx : &ctx->dctx;
  73     if (ivec == NULL) {
  74         /* alloca ? */
  75         size_t len2 = EVP_CIPHER_CTX_iv_length(c);
  76         void *loiv = malloc(len2);
  77         if (loiv == NULL) {
  78             krb5_clear_error_message(context);
  79             return ENOMEM;
  80         }
  81         memset(loiv, 0, len2);
  82         EVP_CipherInit_ex(c, NULL, NULL, NULL, loiv, -1);
  83         free(loiv);
  84     } else
  85         EVP_CipherInit_ex(c, NULL, NULL, NULL, ivec, -1);
  86     EVP_Cipher(c, data, data, len);
  87     return 0;
  88 }
  89
  90 static const unsigned char zero_ivec[EVP_MAX_BLOCK_LENGTH] = { 0 };
  91
  92 krb5_error_code
  93 _krb5_evp_encrypt_cts(krb5_context context,
  94                       struct _krb5_key_data *key,
  95                       void *data,
  96                       size_t len,
  97                       krb5_boolean encryptp,
  98                       int usage,
  99                       void *ivec)
 100 {
 101     size_t i, blocksize;
 102     struct _krb5_evp_schedule *ctx = key->schedule->data;
 103     unsigned char tmp[EVP_MAX_BLOCK_LENGTH], ivec2[EVP_MAX_BLOCK_LENGTH];
 104     EVP_CIPHER_CTX *c;
 105     unsigned char *p;
 106
 107     c = encryptp ? &ctx->ectx : &ctx->dctx;
 108
 109     blocksize = EVP_CIPHER_CTX_block_size(c);
 110
 111     if (len < blocksize) {
 112         krb5_set_error_message(context, EINVAL,
 113                                "message block too short");
 114         return EINVAL;
 115     } else if (len == blocksize) {
 116         EVP_CipherInit_ex(c, NULL, NULL, NULL, zero_ivec, -1);
 117         EVP_Cipher(c, data, data, len);
 118         return 0;
 119     }
 120
 121     if (ivec)
 122         EVP_CipherInit_ex(c, NULL, NULL, NULL, ivec, -1);
 123     else
 124         EVP_CipherInit_ex(c, NULL, NULL, NULL, zero_ivec, -1);
 125
 126     if (encryptp) {
 127
 128         p = data;
 129         i = ((len - 1) / blocksize) * blocksize;
 130         EVP_Cipher(c, p, p, i);
 131         p += i - blocksize;
 132         len -= i;
 133         memcpy(ivec2, p, blocksize);
 134
 135         for (i = 0; i < len; i++)
 136             tmp[i] = p[i + blocksize] ^ ivec2[i];
 137         for (; i < blocksize; i++)
 138             tmp[i] = 0 ^ ivec2[i];
 139
 140         EVP_CipherInit_ex(c, NULL, NULL, NULL, zero_ivec, -1);
 141         EVP_Cipher(c, p, tmp, blocksize);
 142
 143         memcpy(p + blocksize, ivec2, len);
 144         if (ivec)
 145             memcpy(ivec, p, blocksize);
 146     } else {
 147         unsigned char tmp2[EVP_MAX_BLOCK_LENGTH], tmp3[EVP_MAX_BLOCK_LENGTH];
 148
 149         p = data;
 150         if (len > blocksize * 2) {
 151             /* remove last two blocks and round up, decrypt this with cbc, then do cts dance */
 152             i = ((((len - blocksize * 2) + blocksize - 1) / blocksize) * blocksize);
 153             memcpy(ivec2, p + i - blocksize, blocksize);
 154             EVP_Cipher(c, p, p, i);
 155             p += i;
 156             len -= i + blocksize;
 157         } else {
 158             if (ivec)
 159                 memcpy(ivec2, ivec, blocksize);
 160             else
 161                 memcpy(ivec2, zero_ivec, blocksize);
 162             len -= blocksize;
 163         }
 164
 165         memcpy(tmp, p, blocksize);
 166         EVP_CipherInit_ex(c, NULL, NULL, NULL, zero_ivec, -1);
 167         EVP_Cipher(c, tmp2, p, blocksize);
 168
 169         memcpy(tmp3, p + blocksize, len);
 170         memcpy(tmp3 + len, tmp2 + len, blocksize - len); /* xor 0 */
 171
 172         for (i = 0; i < len; i++)
 173             p[i + blocksize] = tmp2[i] ^ tmp3[i];
 174
 175         EVP_CipherInit_ex(c, NULL, NULL, NULL, zero_ivec, -1);
 176         EVP_Cipher(c, p, tmp3, blocksize);
 177
 178         for (i = 0; i < blocksize; i++)
 179             p[i] ^= ivec2[i];
 180         if (ivec)
 181             memcpy(ivec, tmp, blocksize);
 182     }
 183     return 0;
 184 }