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 #include <roken.h>
  36
  37 #ifdef KRB5
  38 #include <krb5-types.h>
  39 #endif
  40
  41 #include "rijndael-alg-fst.h"
  42 #include "aes.h"
  43
  44 int
  45 AES_set_encrypt_key(const unsigned char *userkey, const int bits, AES_KEY *key)
  46 {
  47     key->rounds = rijndaelKeySetupEnc(key->key, userkey, bits);
  48     if (key->rounds == 0)
  49         return -1;
  50     return 0;
  51 }
  52
  53 int
  54 AES_set_decrypt_key(const unsigned char *userkey, const int bits, AES_KEY *key)
  55 {
  56     key->rounds = rijndaelKeySetupDec(key->key, userkey, bits);
  57     if (key->rounds == 0)
  58         return -1;
  59     return 0;
  60 }
  61
  62 void
  63 AES_encrypt(const unsigned char *in, unsigned char *out, const AES_KEY *key)
  64 {
  65     rijndaelEncrypt(key->key, key->rounds, in, out);
  66 }
  67
  68 void
  69 AES_decrypt(const unsigned char *in, unsigned char *out, const AES_KEY *key)
  70 {
  71     rijndaelDecrypt(key->key, key->rounds, in, out);
  72 }
  73
  74 void
  75 AES_cbc_encrypt(const unsigned char *in, unsigned char *out,
  76                 unsigned long size, const AES_KEY *key,
  77                 unsigned char *iv, int forward_encrypt)
  78 {
  79     unsigned char tmp[AES_BLOCK_SIZE];
  80     int i;
  81
  82     if (forward_encrypt) {
  83         while (size >= AES_BLOCK_SIZE) {
  84             for (i = 0; i < AES_BLOCK_SIZE; i++)
  85                 tmp[i] = in[i] ^ iv[i];
  86             AES_encrypt(tmp, out, key);
  87             memcpy(iv, out, AES_BLOCK_SIZE);
  88             size -= AES_BLOCK_SIZE;
  89             in += AES_BLOCK_SIZE;
  90             out += AES_BLOCK_SIZE;
  91         }
  92         if (size) {
  93             for (i = 0; i < size; i++)
  94                 tmp[i] = in[i] ^ iv[i];
  95             for (i = size; i < AES_BLOCK_SIZE; i++)
  96                 tmp[i] = iv[i];
  97             AES_encrypt(tmp, out, key);
  98             memcpy(iv, out, AES_BLOCK_SIZE);
  99         }
 100     } else {
 101         while (size >= AES_BLOCK_SIZE) {
 102             memcpy(tmp, in, AES_BLOCK_SIZE);
 103             AES_decrypt(tmp, out, key);
 104             for (i = 0; i < AES_BLOCK_SIZE; i++)
 105                 out[i] ^= iv[i];
 106             memcpy(iv, tmp, AES_BLOCK_SIZE);
 107             size -= AES_BLOCK_SIZE;
 108             in += AES_BLOCK_SIZE;
 109             out += AES_BLOCK_SIZE;
 110         }
 111         if (size) {
 112             memcpy(tmp, in, AES_BLOCK_SIZE);
 113             AES_decrypt(tmp, out, key);
 114             for (i = 0; i < size; i++)
 115                 out[i] ^= iv[i];
 116             memcpy(iv, tmp, AES_BLOCK_SIZE);
 117         }
 118     }
 119 }
 120
 121 void
 122 AES_cfb8_encrypt(const unsigned char *in, unsigned char *out,
 123                  unsigned long size, const AES_KEY *key,
 124                  unsigned char *iv, int forward_encrypt)
 125 {
 126     int i;
 127
 128     for (i = 0; i < size; i++) {
 129         unsigned char tmp[AES_BLOCK_SIZE + 1];
 130
 131         memcpy(tmp, iv, AES_BLOCK_SIZE);
 132         AES_encrypt(iv, iv, key);
 133         if (!forward_encrypt) {
 134             tmp[AES_BLOCK_SIZE] = in[i];
 135         }
 136         out[i] = in[i] ^ iv[0];
 137         if (forward_encrypt) {
 138             tmp[AES_BLOCK_SIZE] = out[i];
 139         }
 140         memcpy(iv, &tmp[1], AES_BLOCK_SIZE);
 141     }
 142 }