src/libstrongswan/plugins/blowfish/blowfish_crypter.c

   1 /*
   2  * Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
   3  *
   4  * This package is an SSL implementation written
   5  * by Eric Young (eay@cryptsoft.com).
   6  * The implementation was written so as to conform with Netscapes SSL.
   7  *
   8  * This library is free for commercial and non-commercial use as long as
   9  * the following conditions are aheared to.  The following conditions
  10  * apply to all code found in this distribution, be it the RC4, RSA,
  11  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
  12  * included with this distribution is covered by the same copyright terms
  13  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
  14  *
  15  * Copyright remains Eric Young's, and as such any Copyright notices in
  16  * the code are not to be removed.
  17  * If this package is used in a product, Eric Young should be given attribution
  18  * as the author of the parts of the library used.
  19  * This can be in the form of a textual message at program startup or
  20  * in documentation (online or textual) provided with the package.
  21  *
  22  * Redistribution and use in source and binary forms, with or without
  23  * modification, are permitted provided that the following conditions
  24  * are met:
  25  * 1. Redistributions of source code must retain the copyright
  26  *    notice, this list of conditions and the following disclaimer.
  27  * 2. Redistributions in binary form must reproduce the above copyright
  28  *    notice, this list of conditions and the following disclaimer in the
  29  *    documentation and/or other materials provided with the distribution.
  30  * 3. All advertising materials mentioning features or use of this software
  31  *    must display the following acknowledgement:
  32  *    "This product includes cryptographic software written by
  33  *     Eric Young (eay@cryptsoft.com)"
  34  *    The word 'cryptographic' can be left out if the rouines from the library
  35  *    being used are not cryptographic related :-).
  36  * 4. If you include any Windows specific code (or a derivative thereof) from
  37  *    the apps directory (application code) you must include an acknowledgement:
  38  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
  39  *
  40  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
  41  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  42  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  43  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  44  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  45  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  46  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  47  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  48  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  49  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  50  * SUCH DAMAGE.
  51  *
  52  * The licence and distribution terms for any publically available version or
  53  * derivative of this code cannot be changed.  i.e. this code cannot simply be
  54  * copied and put under another distribution licence
  55  * [including the GNU Public Licence.]
  56  */
  57
  58 #include "blowfish.h"
  59
  60 /* Blowfish as implemented from 'Blowfish: Springer-Verlag paper'
  61  * (From LECTURE NOTES IN COMPUTER SCIENCE 809, FAST SOFTWARE ENCRYPTION,
  62  * CAMBRIDGE SECURITY WORKSHOP, CAMBRIDGE, U.K., DECEMBER 9-11, 1993)
  63  */
  64
  65 #include "blowfish_crypter.h"
  66
  67 #define BLOWFISH_BLOCK_SIZE             16
  68
  69 typedef struct private_blowfish_crypter_t private_blowfish_crypter_t;
  70
  71 /**
  72  * Class implementing the Blowfish symmetric encryption algorithm.
  73  *
  74  * @ingroup crypters
  75  */
  76 struct private_blowfish_crypter_t {
  77
  78         /**
  79          * Public part of this class.
  80          */
  81         blowfish_crypter_t public;
  82
  83         /**
  84          * Blowfish key schedule
  85          */
  86         BF_KEY schedule;
  87
  88         /**
  89         * Key size of this Blowfish cipher object.
  90         */
  91         u_int32_t key_size;
  92 };
  93
  94 /**
  95  * Implementation of crypter_t.decrypt.
  96  */
  97 static void decrypt(private_blowfish_crypter_t *this, chunk_t data, chunk_t iv,
  98                                         chunk_t *decrypted)
  99 {
 100         u_int8_t *in, *out;
 101
 102         if (decrypted)
 103         {
 104                 *decrypted = chunk_alloc(data.len);
 105                 out = decrypted->ptr;
 106         }
 107         else
 108         {
 109                 out = data.ptr;
 110         }
 111         in = data.ptr;
 112
 113    BF_cbc_encrypt(in, out, data.len, &this->schedule, iv.ptr, FALSE);
 114 }
 115
 116 /**
 117  * Implementation of crypter_t.decrypt.
 118  */
 119 static void encrypt (private_blowfish_crypter_t *this, chunk_t data, chunk_t iv,
 120                                          chunk_t *encrypted)
 121 {
 122         u_int8_t *in, *out;
 123
 124         if (encrypted)
 125         {
 126                 *encrypted = chunk_alloc(data.len);
 127                 out = encrypted->ptr;
 128         }
 129         else
 130         {
 131                 out = data.ptr;
 132         }
 133         in = data.ptr;
 134
 135    BF_cbc_encrypt(in, out, data.len, &this->schedule, iv.ptr, TRUE);
 136 }
 137
 138 /**
 139  * Implementation of crypter_t.get_block_size.
 140  */
 141 static size_t get_block_size (private_blowfish_crypter_t *this)
 142 {
 143         return BLOWFISH_BLOCK_SIZE;
 144 }
 145
 146 /**
 147  * Implementation of crypter_t.get_key_size.
 148  */
 149 static size_t get_key_size (private_blowfish_crypter_t *this)
 150 {
 151         return this->key_size;
 152 }
 153
 154 /**
 155  * Implementation of crypter_t.set_key.
 156  */
 157 static void set_key (private_blowfish_crypter_t *this, chunk_t key)
 158 {
 159         BF_set_key(&this->schedule, key.len , key.ptr);
 160 }
 161
 162 /**
 163  * Implementation of crypter_t.destroy and blowfish_crypter_t.destroy.
 164  */
 165 static void destroy (private_blowfish_crypter_t *this)
 166 {
 167         free(this);
 168 }
 169
 170 /*
 171  * Described in header
 172  */
 173 blowfish_crypter_t *blowfish_crypter_create(encryption_algorithm_t algo, size_t key_size)
 174 {
 175         private_blowfish_crypter_t *this;
 176
 177         if (algo != ENCR_BLOWFISH)
 178         {
 179                 return NULL;
 180         }
 181
 182         this = malloc_thing(private_blowfish_crypter_t);
 183
 184         this->key_size = key_size;
 185         this->public.crypter_interface.encrypt = (void (*) (crypter_t *, chunk_t,chunk_t, chunk_t *)) encrypt;
 186         this->public.crypter_interface.decrypt = (void (*) (crypter_t *, chunk_t , chunk_t, chunk_t *)) decrypt;
 187         this->public.crypter_interface.get_block_size = (size_t (*) (crypter_t *)) get_block_size;
 188         this->public.crypter_interface.get_key_size = (size_t (*) (crypter_t *)) get_key_size;
 189         this->public.crypter_interface.set_key = (void (*) (crypter_t *,chunk_t)) set_key;
 190         this->public.crypter_interface.destroy = (void (*) (crypter_t *)) destroy;
 191
 192         return &(this->public);
 193 }