crypto/openssl-0.9.7d/crypto/bf/bf_cfb64.c

   1 /* crypto/bf/bf_cfb64.c */
   2 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
   3  * All rights reserved.
   4  *
   5  * This package is an SSL implementation written
   6  * by Eric Young (eay@cryptsoft.com).
   7  * The implementation was written so as to conform with Netscapes SSL.
   8  *
   9  * This library is free for commercial and non-commercial use as long as
  10  * the following conditions are aheared to.  The following conditions
  11  * apply to all code found in this distribution, be it the RC4, RSA,
  12  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
  13  * included with this distribution is covered by the same copyright terms
  14  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
  15  *
  16  * Copyright remains Eric Young's, and as such any Copyright notices in
  17  * the code are not to be removed.
  18  * If this package is used in a product, Eric Young should be given attribution
  19  * as the author of the parts of the library used.
  20  * This can be in the form of a textual message at program startup or
  21  * in documentation (online or textual) provided with the package.
  22  *
  23  * Redistribution and use in source and binary forms, with or without
  24  * modification, are permitted provided that the following conditions
  25  * are met:
  26  * 1. Redistributions of source code must retain the copyright
  27  *    notice, this list of conditions and the following disclaimer.
  28  * 2. Redistributions in binary form must reproduce the above copyright
  29  *    notice, this list of conditions and the following disclaimer in the
  30  *    documentation and/or other materials provided with the distribution.
  31  * 3. All advertising materials mentioning features or use of this software
  32  *    must display the following acknowledgement:
  33  *    "This product includes cryptographic software written by
  34  *     Eric Young (eay@cryptsoft.com)"
  35  *    The word 'cryptographic' can be left out if the rouines from the library
  36  *    being used are not cryptographic related :-).
  37  * 4. If you include any Windows specific code (or a derivative thereof) from
  38  *    the apps directory (application code) you must include an acknowledgement:
  39  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
  40  *
  41  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
  42  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  43  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  44  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  45  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  46  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  47  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  48  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  49  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  50  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  51  * SUCH DAMAGE.
  52  *
  53  * The licence and distribution terms for any publically available version or
  54  * derivative of this code cannot be changed.  i.e. this code cannot simply be
  55  * copied and put under another distribution licence
  56  * [including the GNU Public Licence.]
  57  */
  58
  59 #include <openssl/blowfish.h>
  60 #include "bf_locl.h"
  61
  62 /* The input and output encrypted as though 64bit cfb mode is being
  63  * used.  The extra state information to record how much of the
  64  * 64bit block we have used is contained in *num;
  65  */
  66
  67 void BF_cfb64_encrypt(const unsigned char *in, unsigned char *out, long length,
  68              const BF_KEY *schedule, unsigned char *ivec, int *num, int encrypt)
  69         {
  70         register BF_LONG v0,v1,t;
  71         register int n= *num;
  72         register long l=length;
  73         BF_LONG ti[2];
  74         unsigned char *iv,c,cc;
  75
  76         iv=(unsigned char *)ivec;
  77         if (encrypt)
  78                 {
  79                 while (l--)
  80                         {
  81                         if (n == 0)
  82                                 {
  83                                 n2l(iv,v0); ti[0]=v0;
  84                                 n2l(iv,v1); ti[1]=v1;
  85                                 BF_encrypt((BF_LONG *)ti,schedule);
  86                                 iv=(unsigned char *)ivec;
  87                                 t=ti[0]; l2n(t,iv);
  88                                 t=ti[1]; l2n(t,iv);
  89                                 iv=(unsigned char *)ivec;
  90                                 }
  91                         c= *(in++)^iv[n];
  92                         *(out++)=c;
  93                         iv[n]=c;
  94                         n=(n+1)&0x07;
  95                         }
  96                 }
  97         else
  98                 {
  99                 while (l--)
 100                         {
 101                         if (n == 0)
 102                                 {
 103                                 n2l(iv,v0); ti[0]=v0;
 104                                 n2l(iv,v1); ti[1]=v1;
 105                                 BF_encrypt((BF_LONG *)ti,schedule);
 106                                 iv=(unsigned char *)ivec;
 107                                 t=ti[0]; l2n(t,iv);
 108                                 t=ti[1]; l2n(t,iv);
 109                                 iv=(unsigned char *)ivec;
 110                                 }
 111                         cc= *(in++);
 112                         c=iv[n];
 113                         iv[n]=cc;
 114                         *(out++)=c^cc;
 115                         n=(n+1)&0x07;
 116                         }
 117                 }
 118         v0=v1=ti[0]=ti[1]=t=c=cc=0;
 119         *num=n;
 120         }
 121