crypto/des/qud_cksm.c

   1 /* crypto/des/qud_cksm.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 /* From "Message Authentication"  R.R. Jueneman, S.M. Matyas, C.H. Meyer
  60  * IEEE Communications Magazine Sept 1985 Vol. 23 No. 9 p 29-40
  61  * This module in only based on the code in this paper and is
  62  * almost definitely not the same as the MIT implementation.
  63  */
  64 #include "des_locl.h"
  65
  66 /* bug fix for dos - 7/6/91 - Larry hughes@logos.ucs.indiana.edu */
  67 #define Q_B0(a) (((DES_LONG)(a)))
  68 #define Q_B1(a) (((DES_LONG)(a))<<8)
  69 #define Q_B2(a) (((DES_LONG)(a))<<16)
  70 #define Q_B3(a) (((DES_LONG)(a))<<24)
  71
  72 /* used to scramble things a bit */
  73 /* Got the value MIT uses via brute force :-) 2/10/90 eay */
  74 #define NOISE   ((DES_LONG)83653421L)
  75
  76 DES_LONG des_quad_cksum(const unsigned char *input, des_cblock output[],
  77              long length, int out_count, des_cblock *seed)
  78         {
  79         DES_LONG z0,z1,t0,t1;
  80         int i;
  81         long l;
  82         const unsigned char *cp;
  83         unsigned char *lp;
  84
  85         if (out_count < 1) out_count=1;
  86         lp = &(output[0])[0];
  87
  88         z0=Q_B0((*seed)[0])|Q_B1((*seed)[1])|Q_B2((*seed)[2])|Q_B3((*seed)[3]);
  89         z1=Q_B0((*seed)[4])|Q_B1((*seed)[5])|Q_B2((*seed)[6])|Q_B3((*seed)[7]);
  90
  91         for (i=0; ((i<4)&&(i<out_count)); i++)
  92                 {
  93                 cp=input;
  94                 l=length;
  95                 while (l > 0)
  96                         {
  97                         if (l > 1)
  98                                 {
  99                                 t0= (DES_LONG)(*(cp++));
 100                                 t0|=(DES_LONG)Q_B1(*(cp++));
 101                                 l--;
 102                                 }
 103                         else
 104                                 t0= (DES_LONG)(*(cp++));
 105                         l--;
 106                         /* add */
 107                         t0+=z0;
 108                         t0&=0xffffffffL;
 109                         t1=z1;
 110                         /* square, well sort of square */
 111                         z0=((((t0*t0)&0xffffffffL)+((t1*t1)&0xffffffffL))
 112                                 &0xffffffffL)%0x7fffffffL;
 113                         z1=((t0*((t1+NOISE)&0xffffffffL))&0xffffffffL)%0x7fffffffL;
 114                         }
 115                 if (lp != NULL)
 116                         {
 117                         /* I believe I finally have things worked out.
 118                          * The MIT library assumes that the checksum
 119                          * is one huge number and it is returned in a
 120                          * host dependant byte order.
 121                          */
 122                         static DES_LONG ltmp=1;
 123                         static unsigned char *c=(unsigned char *)&ltmp;
 124
 125                         if (c[0])
 126                                 {
 127                                 l2c(z0,lp);
 128                                 l2c(z1,lp);
 129                                 }
 130                         else
 131                                 {
 132                                 lp = &(output[out_count-i-1])[0];
 133                                 l2n(z1,lp);
 134                                 l2n(z0,lp);
 135                                 }
 136                         }
 137                 }
 138         return(z0);
 139         }
 140