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 #include "config.h"
  35
  36
  37 #ifdef KRB5
  38 #include <krb5-types.h>
  39 #endif
  40
  41 #include <string.h>
  42
  43 #include "rijndael-alg-fst.h"
  44 #include "aes.h"
  45
  46 int
  47 AES_set_encrypt_key(const unsigned char *userkey, const int bits, AES_KEY *key)
  48 {
  49     key->rounds = rijndaelKeySetupEnc(key->key, userkey, bits);
  50     if (key->rounds == 0)
  51         return -1;
  52     return 0;
  53 }
  54
  55 int
  56 AES_set_decrypt_key(const unsigned char *userkey, const int bits, AES_KEY *key)
  57 {
  58     key->rounds = rijndaelKeySetupDec(key->key, userkey, bits);
  59     if (key->rounds == 0)
  60         return -1;
  61     return 0;
  62 }
  63
  64 void
  65 AES_encrypt(const unsigned char *in, unsigned char *out, const AES_KEY *key)
  66 {
  67     rijndaelEncrypt(key->key, key->rounds, in, out);
  68 }
  69
  70 void
  71 AES_decrypt(const unsigned char *in, unsigned char *out, const AES_KEY *key)
  72 {
  73     rijndaelDecrypt(key->key, key->rounds, in, out);
  74 }
  75
  76 void
  77 AES_cbc_encrypt(const unsigned char *in, unsigned char *out,
  78                 unsigned long size, const AES_KEY *key,
  79                 unsigned char *iv, int forward_encrypt)
  80 {
  81     unsigned char tmp[AES_BLOCK_SIZE];
  82     int i;
  83
  84     if (forward_encrypt) {
  85         while (size >= AES_BLOCK_SIZE) {
  86             for (i = 0; i < AES_BLOCK_SIZE; i++)
  87                 tmp[i] = in[i] ^ iv[i];
  88             AES_encrypt(tmp, out, key);
  89             memcpy(iv, out, AES_BLOCK_SIZE);
  90             size -= AES_BLOCK_SIZE;
  91             in += AES_BLOCK_SIZE;
  92             out += AES_BLOCK_SIZE;
  93         }
  94         if (size) {
  95             for (i = 0; i < size; i++)
  96                 tmp[i] = in[i] ^ iv[i];
  97             for (i = size; i < AES_BLOCK_SIZE; i++)
  98                 tmp[i] = iv[i];
  99             AES_encrypt(tmp, out, key);
 100             memcpy(iv, out, AES_BLOCK_SIZE);
 101         }
 102     } else {
 103         while (size >= AES_BLOCK_SIZE) {
 104             memcpy(tmp, in, AES_BLOCK_SIZE);
 105             AES_decrypt(tmp, out, key);
 106             for (i = 0; i < AES_BLOCK_SIZE; i++)
 107                 out[i] ^= iv[i];
 108             memcpy(iv, tmp, AES_BLOCK_SIZE);
 109             size -= AES_BLOCK_SIZE;
 110             in += AES_BLOCK_SIZE;
 111             out += AES_BLOCK_SIZE;
 112         }
 113         if (size) {
 114             memcpy(tmp, in, AES_BLOCK_SIZE);
 115             AES_decrypt(tmp, out, key);
 116             for (i = 0; i < size; i++)
 117                 out[i] ^= iv[i];
 118             memcpy(iv, tmp, AES_BLOCK_SIZE);
 119         }
 120     }
 121 }