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 /*
  60  * From "Message Authentication" R.R. Jueneman, S.M. Matyas, C.H. Meyer IEEE
  61  * Communications Magazine Sept 1985 Vol. 23 No. 9 p 29-40 This module in
  62  * only based on the code in this paper and is almost definitely not the same
  63  * as the MIT implementation.
  64  */
  65 #include "des_locl.h"
  66
  67 /* bug fix for dos - 7/6/91 - Larry hughes@logos.ucs.indiana.edu */
  68 #define Q_B0(a) (((DES_LONG)(a)))
  69 #define Q_B1(a) (((DES_LONG)(a))<<8)
  70 #define Q_B2(a) (((DES_LONG)(a))<<16)
  71 #define Q_B3(a) (((DES_LONG)(a))<<24)
  72
  73 /* used to scramble things a bit */
  74 /* Got the value MIT uses via brute force :-) 2/10/90 eay */
  75 #define NOISE   ((DES_LONG)83653421L)
  76
  77 DES_LONG DES_quad_cksum(const unsigned char *input, DES_cblock output[],
  78                         long length, int out_count, DES_cblock *seed)
  79 {
  80     DES_LONG z0, z1, t0, t1;
  81     int i;
  82     long l;
  83     const unsigned char *cp;
  84     DES_LONG *lp;
  85
  86     if (out_count < 1)
  87         out_count = 1;
  88     lp = (DES_LONG *)&(output[0])[0];
  89
  90     z0 = Q_B0((*seed)[0]) | Q_B1((*seed)[1]) | Q_B2((*seed)[2]) |
  91         Q_B3((*seed)[3]);
  92     z1 = Q_B0((*seed)[4]) | Q_B1((*seed)[5]) | Q_B2((*seed)[6]) |
  93         Q_B3((*seed)[7]);
  94
  95     for (i = 0; ((i < 4) && (i < out_count)); i++) {
  96         cp = input;
  97         l = length;
  98         while (l > 0) {
  99             if (l > 1) {
 100                 t0 = (DES_LONG)(*(cp++));
 101                 t0 |= (DES_LONG)Q_B1(*(cp++));
 102                 l--;
 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) %
 114                 0x7fffffffL;
 115         }
 116         if (lp != NULL) {
 117             /*
 118              * The MIT library assumes that the checksum is composed of
 119              * 2*out_count 32 bit ints
 120              */
 121             *lp++ = z0;
 122             *lp++ = z1;
 123         }
 124     }
 125     return (z0);
 126 }