crypto/dist/heimdal/lib/hcrypto/aes.c

   1 /*
   2  * Copyright (c) 2003 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
  37 __RCSID("$Heimdal: aes.c 15495 2005-06-18 22:47:33Z lha $"
  38         "$NetBSD$");
  39 #endif
  40
  41 #ifdef KRB5
  42 #include <krb5-types.h>
  43 #endif
  44
  45 #include <string.h>
  46
  47 #include "rijndael-alg-fst.h"
  48 #include "aes.h"
  49
  50 int
  51 AES_set_encrypt_key(const unsigned char *userkey, const int bits, AES_KEY *key)
  52 {
  53     key->rounds = rijndaelKeySetupEnc(key->key, userkey, bits);
  54     if (key->rounds == 0)
  55         return -1;
  56     return 0;
  57 }
  58
  59 int
  60 AES_set_decrypt_key(const unsigned char *userkey, const int bits, AES_KEY *key)
  61 {
  62     key->rounds = rijndaelKeySetupDec(key->key, userkey, bits);
  63     if (key->rounds == 0)
  64         return -1;
  65     return 0;
  66 }
  67
  68 void
  69 AES_encrypt(const unsigned char *in, unsigned char *out, const AES_KEY *key)
  70 {
  71     rijndaelEncrypt(key->key, key->rounds, in, out);
  72 }
  73
  74 void
  75 AES_decrypt(const unsigned char *in, unsigned char *out, const AES_KEY *key)
  76 {
  77     rijndaelDecrypt(key->key, key->rounds, in, out);
  78 }
  79
  80 void
  81 AES_cbc_encrypt(const unsigned char *in, unsigned char *out,
  82                 unsigned long size, const AES_KEY *key,
  83                 unsigned char *iv, int forward_encrypt)
  84 {
  85     unsigned char tmp[AES_BLOCK_SIZE];
  86     int i;
  87
  88     if (forward_encrypt) {
  89         while (size >= AES_BLOCK_SIZE) {
  90             for (i = 0; i < AES_BLOCK_SIZE; i++)
  91                 tmp[i] = in[i] ^ iv[i];
  92             AES_encrypt(tmp, out, key);
  93             memcpy(iv, out, AES_BLOCK_SIZE);
  94             size -= AES_BLOCK_SIZE;
  95             in += AES_BLOCK_SIZE;
  96             out += AES_BLOCK_SIZE;
  97         }
  98         if (size) {
  99             for (i = 0; i < size; i++)
 100                 tmp[i] = in[i] ^ iv[i];
 101             for (i = size; i < AES_BLOCK_SIZE; i++)
 102                 tmp[i] = iv[i];
 103             AES_encrypt(tmp, out, key);
 104             memcpy(iv, out, AES_BLOCK_SIZE);
 105         }
 106     } else {
 107         while (size >= AES_BLOCK_SIZE) {
 108             memcpy(tmp, in, AES_BLOCK_SIZE);
 109             AES_decrypt(tmp, out, key);
 110             for (i = 0; i < AES_BLOCK_SIZE; i++)
 111                 out[i] ^= iv[i];
 112             memcpy(iv, tmp, AES_BLOCK_SIZE);
 113             size -= AES_BLOCK_SIZE;
 114             in += AES_BLOCK_SIZE;
 115             out += AES_BLOCK_SIZE;
 116         }
 117         if (size) {
 118             memcpy(tmp, in, AES_BLOCK_SIZE);
 119             AES_decrypt(tmp, out, key);
 120             for (i = 0; i < size; i++)
 121                 out[i] ^= iv[i];
 122             memcpy(iv, tmp, AES_BLOCK_SIZE);
 123         }
 124     }
 125 }