/* lib/des/des_locl.h */
/* Copyright (C) 1995 Eric Young (eay@mincom.oz.au)
 * All rights reserved.
 * 
 * This file is part of an SSL implementation written
 * by Eric Young (eay@mincom.oz.au).
 * The implementation was written so as to conform with Netscapes SSL
 * specification.  This library and applications are
 * FREE FOR COMMERCIAL AND NON-COMMERCIAL USE
 * as long as the following conditions are aheared to.
 * 
 * Copyright remains Eric Young's, and as such any Copyright notices in
 * the code are not to be removed.  If this code is used in a product,
 * Eric Young should be given attribution as the author of the parts used.
 * This can be in the form of a textual message at program startup or
 * in documentation (online or textual) provided with the package.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *    This product includes software developed by Eric Young (eay@mincom.oz.au)
 * 
 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * 
 * The licence and distribution terms for any publically available version or
 * derivative of this code cannot be changed.  i.e. this code cannot simply be
 * copied and put under another distribution licence
 * [including the GNU Public Licence.]
 */

#ifndef HEADER_DES_LOCL_H
#define HEADER_DES_LOCL_H
#include <stdio.h>
#include <stdlib.h>
#ifdef WIN32
#define MSDOS
#define _fstrlen strlen
#define _fmemset memset
#endif
#ifndef MSDOS
#include <unistd.h>
#endif
#include "des.h"

/* the following is tweaked from a config script, that is why it is a
 * protected undef/define */
#ifndef DES_USE_PTR
#undef DES_USE_PTR
#endif

#ifdef MSDOS            /* Visual C++ 2.1 (Windows NT/95) */
#include <stdlib.h>
#include <time.h>
#include <io.h>
#define RAND
#undef PROTO
#define PROTO
#endif

#if defined(__STDC__) || defined(VMS) || defined(M_XENIX) || defined(MSDOS)
#include <string.h>
#endif

#ifndef RAND
#define RAND
#endif

#ifdef MSDOS
#define getpid() 2
#ifdef WIN32
#define FAR
#else
#define FAR __far
#endif
//extern int errno;
#define RAND
#undef PROTO
#define PROTO
#endif

#if defined(NOCONST)
#define const
#endif

#ifdef __STDC__
#undef PROTO
#define PROTO
#endif

#ifdef RAND
#define srandom(s) srand(s)
#define random rand
#endif

#define ITERATIONS 16
#define HALF_ITERATIONS 8

/* used in des_read and des_write */
#define MAXWRITE        (1024*16)
#define BSIZE           (MAXWRITE+4)

#define c2l(c,l)        (l =((unsigned long)(*((c)++)))    , \
                         l|=((unsigned long)(*((c)++)))<< 8L, \
                         l|=((unsigned long)(*((c)++)))<<16L, \
                         l|=((unsigned long)(*((c)++)))<<24L)

/* NOTE - c is not incremented as per c2l */
#define c2ln(c,l1,l2,n) { \
                        c+=n; \
                        l1=l2=0; \
                        switch (n) { \
                        case 8: l2 =((unsigned long)(*(--(c))))<<24L; \
                        case 7: l2|=((unsigned long)(*(--(c))))<<16L; \
                        case 6: l2|=((unsigned long)(*(--(c))))<< 8L; \
                        case 5: l2|=((unsigned long)(*(--(c))));     \
                        case 4: l1 =((unsigned long)(*(--(c))))<<24L; \
                        case 3: l1|=((unsigned long)(*(--(c))))<<16L; \
                        case 2: l1|=((unsigned long)(*(--(c))))<< 8L; \
                        case 1: l1|=((unsigned long)(*(--(c))));     \
                                } \
                        }

#define l2c(l,c)        (*((c)++)=(unsigned char)(((l)     )&0xff), \
                         *((c)++)=(unsigned char)(((l)>> 8L)&0xff), \
                         *((c)++)=(unsigned char)(((l)>>16L)&0xff), \
                         *((c)++)=(unsigned char)(((l)>>24L)&0xff))

/* replacements for htonl and ntohl since I have no idea what to do
 * when faced with machines with 8 byte longs. */
#define HDRSIZE 4

#define n2l(c,l)        (l =((unsigned long)(*((c)++)))<<24L, \
                         l|=((unsigned long)(*((c)++)))<<16L, \
                         l|=((unsigned long)(*((c)++)))<< 8L, \
                         l|=((unsigned long)(*((c)++))))

#define l2n(l,c)        (*((c)++)=(unsigned char)(((l)>>24L)&0xff), \
                         *((c)++)=(unsigned char)(((l)>>16L)&0xff), \
                         *((c)++)=(unsigned char)(((l)>> 8L)&0xff), \
                         *((c)++)=(unsigned char)(((l)     )&0xff))

/* NOTE - c is not incremented as per l2c */
#define l2cn(l1,l2,c,n) { \
                        c+=n; \
                        switch (n) { \
                        case 8: *(--(c))=(unsigned char)(((l2)>>24L)&0xff); \
                        case 7: *(--(c))=(unsigned char)(((l2)>>16L)&0xff); \
                        case 6: *(--(c))=(unsigned char)(((l2)>> 8L)&0xff); \
                        case 5: *(--(c))=(unsigned char)(((l2)     )&0xff); \
                        case 4: *(--(c))=(unsigned char)(((l1)>>24L)&0xff); \
                        case 3: *(--(c))=(unsigned char)(((l1)>>16L)&0xff); \
                        case 2: *(--(c))=(unsigned char)(((l1)>> 8L)&0xff); \
                        case 1: *(--(c))=(unsigned char)(((l1)     )&0xff); \
                                } \
                        }

/* The changes to this macro may help or hinder, depending on the
 * compiler and the achitecture.  gcc2 always seems to do well :-).
 * Inspired by Dana How <how@isl.stanford.edu>
 * DO NOT use the alternative version on machines with 8 byte longs. */
#ifdef DES_USR_PTR
#define D_ENCRYPT(L,R,S) { \
        u=((R^s[S  ])<<2);      \
        t= R^s[S+1]; \
        t=((t>>2)+(t<<30)); \
        L^= \
        *(unsigned long *)(des_SP+0x0100+((t    )&0xfc))+ \
        *(unsigned long *)(des_SP+0x0300+((t>> 8)&0xfc))+ \
        *(unsigned long *)(des_SP+0x0500+((t>>16)&0xfc))+ \
        *(unsigned long *)(des_SP+0x0700+((t>>24)&0xfc))+ \
        *(unsigned long *)(des_SP+       ((u    )&0xfc))+ \
        *(unsigned long *)(des_SP+0x0200+((u>> 8)&0xfc))+ \
        *(unsigned long *)(des_SP+0x0400+((u>>16)&0xfc))+ \
        *(unsigned long *)(des_SP+0x0600+((u>>24)&0xfc)); }
#else /* original version */
#ifdef MSDOS
#define D_ENCRYPT(L,R,S)        \
        U.l=R^s[S+1]; \
        T.s[0]=((U.s[0]>>4)|(U.s[1]<<12))&0x3f3f; \
        T.s[1]=((U.s[1]>>4)|(U.s[0]<<12))&0x3f3f; \
        U.l=(R^s[S  ])&0x3f3f3f3fL; \
        L^=     des_SPtrans[1][(T.c[0])]| \
                des_SPtrans[3][(T.c[1])]| \
                des_SPtrans[5][(T.c[2])]| \
                des_SPtrans[7][(T.c[3])]| \
                des_SPtrans[0][(U.c[0])]| \
                des_SPtrans[2][(U.c[1])]| \
                des_SPtrans[4][(U.c[2])]| \
                des_SPtrans[6][(U.c[3])];
#else
#define D_ENCRYPT(Q,R,S) {\
        u=(R^s[S  ]); \
        t=R^s[S+1]; \
        t=((t>>4L)+(t<<28L)); \
        Q^=     des_SPtrans[1][(t     )&0x3f]| \
                des_SPtrans[3][(t>> 8L)&0x3f]| \
                des_SPtrans[5][(t>>16L)&0x3f]| \
                des_SPtrans[7][(t>>24L)&0x3f]| \
                des_SPtrans[0][(u     )&0x3f]| \
                des_SPtrans[2][(u>> 8L)&0x3f]| \
                des_SPtrans[4][(u>>16L)&0x3f]| \
                des_SPtrans[6][(u>>24L)&0x3f]; }
#endif
#endif

        /* IP and FP
         * The problem is more of a geometric problem that random bit fiddling.
         0  1  2  3  4  5  6  7      62 54 46 38 30 22 14  6
         8  9 10 11 12 13 14 15      60 52 44 36 28 20 12  4
        16 17 18 19 20 21 22 23      58 50 42 34 26 18 10  2
        24 25 26 27 28 29 30 31  to  56 48 40 32 24 16  8  0

        32 33 34 35 36 37 38 39      63 55 47 39 31 23 15  7
        40 41 42 43 44 45 46 47      61 53 45 37 29 21 13  5
        48 49 50 51 52 53 54 55      59 51 43 35 27 19 11  3
        56 57 58 59 60 61 62 63      57 49 41 33 25 17  9  1

        The output has been subject to swaps of the form
        0 1 -> 3 1 but the odd and even bits have been put into
        2 3    2 0
        different words.  The main trick is to remember that
        t=((l>>size)^r)&(mask);
        r^=t;
        l^=(t<<size);
        can be used to swap and move bits between words.

        So l =  0  1  2  3  r = 16 17 18 19
                4  5  6  7      20 21 22 23
                8  9 10 11      24 25 26 27
               12 13 14 15      28 29 30 31
        becomes (for size == 2 and mask == 0x3333)
           t =   2^16  3^17 -- --   l =  0  1 16 17  r =  2  3 18 19
                 6^20  7^21 -- --        4  5 20 21       6  7 22 23
                10^24 11^25 -- --        8  9 24 25      10 11 24 25
                14^28 15^29 -- --       12 13 28 29      14 15 28 29

        Thanks for hints from Richard Outerbridge - he told me IP&FP
        could be done in 15 xor, 10 shifts and 5 ands.
        When I finally started to think of the problem in 2D
        I first got ~42 operations without xors.  When I remembered
        how to use xors :-) I got it to its final state.
        */
#define PERM_OP(a,b,t,n,m) ((t)=((((a)>>(n))^(b))&(m)),\
        (b)^=(t),\
        (a)^=((t)<<(n)))

#define IP(l,r) \
        { \
        register unsigned long tt; \
        PERM_OP(r,l,tt, 4,0x0f0f0f0fL); \
        PERM_OP(l,r,tt,16,0x0000ffffL); \
        PERM_OP(r,l,tt, 2,0x33333333L); \
        PERM_OP(l,r,tt, 8,0x00ff00ffL); \
        PERM_OP(r,l,tt, 1,0x55555555L); \
        }

#define FP(l,r) \
        { \
        register unsigned long tt; \
        PERM_OP(l,r,tt, 1,0x55555555L); \
        PERM_OP(r,l,tt, 8,0x00ff00ffL); \
        PERM_OP(l,r,tt, 2,0x33333333L); \
        PERM_OP(r,l,tt,16,0x0000ffffL); \
        PERM_OP(l,r,tt, 4,0x0f0f0f0fL); \
        }
#endif
