lib/crypto/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 "replace.h"
  35 #include "aes.h"
  36
  37 #ifdef SAMBA_RIJNDAEL
  38 #include "rijndael-alg-fst.h"
  39
  40 int
  41 AES_set_encrypt_key(const unsigned char *userkey, const int bits, AES_KEY *key)
  42 {
  43     key->rounds = rijndaelKeySetupEnc(key->key, userkey, bits);
  44     if (key->rounds == 0)
  45         return -1;
  46     return 0;
  47 }
  48
  49 int
  50 AES_set_decrypt_key(const unsigned char *userkey, const int bits, AES_KEY *key)
  51 {
  52     key->rounds = rijndaelKeySetupDec(key->key, userkey, bits);
  53     if (key->rounds == 0)
  54         return -1;
  55     return 0;
  56 }
  57
  58 void
  59 AES_encrypt(const unsigned char *in, unsigned char *out, const AES_KEY *key)
  60 {
  61     rijndaelEncrypt(key->key, key->rounds, in, out);
  62 }
  63
  64 void
  65 AES_decrypt(const unsigned char *in, unsigned char *out, const AES_KEY *key)
  66 {
  67     rijndaelDecrypt(key->key, key->rounds, in, out);
  68 }
  69 #endif /* SAMBA_RIJNDAEL */
  70
  71 #ifdef SAMBA_AES_CBC_ENCRYPT
  72 void
  73 AES_cbc_encrypt(const unsigned char *in, unsigned char *out,
  74                 unsigned long size, const AES_KEY *key,
  75                 unsigned char *iv, int forward_encrypt)
  76 {
  77     unsigned char tmp[AES_BLOCK_SIZE];
  78     int i;
  79
  80     if (forward_encrypt) {
  81         while (size >= AES_BLOCK_SIZE) {
  82             for (i = 0; i < AES_BLOCK_SIZE; i++)
  83                 tmp[i] = in[i] ^ iv[i];
  84             AES_encrypt(tmp, out, key);
  85             memcpy(iv, out, AES_BLOCK_SIZE);
  86             size -= AES_BLOCK_SIZE;
  87             in += AES_BLOCK_SIZE;
  88             out += AES_BLOCK_SIZE;
  89         }
  90         if (size) {
  91             for (i = 0; i < size; i++)
  92                 tmp[i] = in[i] ^ iv[i];
  93             for (i = size; i < AES_BLOCK_SIZE; i++)
  94                 tmp[i] = iv[i];
  95             AES_encrypt(tmp, out, key);
  96             memcpy(iv, out, AES_BLOCK_SIZE);
  97         }
  98     } else {
  99         while (size >= AES_BLOCK_SIZE) {
 100             memcpy(tmp, in, AES_BLOCK_SIZE);
 101             AES_decrypt(tmp, out, key);
 102             for (i = 0; i < AES_BLOCK_SIZE; i++)
 103                 out[i] ^= iv[i];
 104             memcpy(iv, tmp, AES_BLOCK_SIZE);
 105             size -= AES_BLOCK_SIZE;
 106             in += AES_BLOCK_SIZE;
 107             out += AES_BLOCK_SIZE;
 108         }
 109         if (size) {
 110             memcpy(tmp, in, AES_BLOCK_SIZE);
 111             AES_decrypt(tmp, out, key);
 112             for (i = 0; i < size; i++)
 113                 out[i] ^= iv[i];
 114             memcpy(iv, tmp, AES_BLOCK_SIZE);
 115         }
 116     }
 117 }
 118 #endif /* SAMBA_AES_CBC_ENCRYPT */
 119
 120 #ifdef SAMBA_AES_CFB8_ENCRYPT
 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 }
 143 #endif /* SAMBA_AES_CFB8_ENCRYPT */