* Copyright (c) 1989 The Regents of the University of California.
* This code is derived from software contributed to Berkeley by
* Phil Karn, derived from original work by Jim Gillogly and
* Redistribution and use in source and binary forms are permitted
* provided that: (1) source distributions retain this entire copyright
* notice and comment, and (2) distributions including binaries display
* the following acknowledgement: ``This product includes software
* developed by the University of California, Berkeley and its contributors''
* in the documentation or other materials provided with the distribution
* and in all advertising materials mentioning features or use of this
* software. Neither the name of the University nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
static char sccsid
[] = "@(#)des.c 5.3 (Berkeley) 6/1/90";
* written 12 Dec 1986 by Phil Karn, KA9Q; large sections adapted from
* the 1977 public-domain program by Jim Gillogly
#include <machine/endian.h>
#if BYTE_ORDER == LITTLE_ENDIAN
static void permute(),perminit(),spinit();
/* Tables defined in the Data Encryption Standard documents */
/* initial permutation IP */
58, 50, 42, 34, 26, 18, 10, 2,
60, 52, 44, 36, 28, 20, 12, 4,
62, 54, 46, 38, 30, 22, 14, 6,
64, 56, 48, 40, 32, 24, 16, 8,
57, 49, 41, 33, 25, 17, 9, 1,
59, 51, 43, 35, 27, 19, 11, 3,
61, 53, 45, 37, 29, 21, 13, 5,
63, 55, 47, 39, 31, 23, 15, 7
/* final permutation IP^-1 */
40, 8, 48, 16, 56, 24, 64, 32,
39, 7, 47, 15, 55, 23, 63, 31,
38, 6, 46, 14, 54, 22, 62, 30,
37, 5, 45, 13, 53, 21, 61, 29,
36, 4, 44, 12, 52, 20, 60, 28,
35, 3, 43, 11, 51, 19, 59, 27,
34, 2, 42, 10, 50, 18, 58, 26,
33, 1, 41, 9, 49, 17, 57, 25
/* expansion operation matrix
* This is for reference only; it is unused in the code
* as the f() function performs it implicitly for speed
/* permuted choice table (key) */
57, 49, 41, 33, 25, 17, 9,
1, 58, 50, 42, 34, 26, 18,
10, 2, 59, 51, 43, 35, 27,
19, 11, 3, 60, 52, 44, 36,
63, 55, 47, 39, 31, 23, 15,
7, 62, 54, 46, 38, 30, 22,
14, 6, 61, 53, 45, 37, 29,
/* number left rotations of pc1 */
1,2,4,6,8,10,12,14,15,17,19,21,23,25,27,28
/* permuted choice key (table) */
/* The (in)famous S-boxes */
static char si
[8][64] = {
14, 4, 13, 1, 2, 15, 11, 8, 3, 10, 6, 12, 5, 9, 0, 7,
0, 15, 7, 4, 14, 2, 13, 1, 10, 6, 12, 11, 9, 5, 3, 8,
4, 1, 14, 8, 13, 6, 2, 11, 15, 12, 9, 7, 3, 10, 5, 0,
15, 12, 8, 2, 4, 9, 1, 7, 5, 11, 3, 14, 10, 0, 6, 13,
15, 1, 8, 14, 6, 11, 3, 4, 9, 7, 2, 13, 12, 0, 5, 10,
3, 13, 4, 7, 15, 2, 8, 14, 12, 0, 1, 10, 6, 9, 11, 5,
0, 14, 7, 11, 10, 4, 13, 1, 5, 8, 12, 6, 9, 3, 2, 15,
13, 8, 10, 1, 3, 15, 4, 2, 11, 6, 7, 12, 0, 5, 14, 9,
10, 0, 9, 14, 6, 3, 15, 5, 1, 13, 12, 7, 11, 4, 2, 8,
13, 7, 0, 9, 3, 4, 6, 10, 2, 8, 5, 14, 12, 11, 15, 1,
13, 6, 4, 9, 8, 15, 3, 0, 11, 1, 2, 12, 5, 10, 14, 7,
1, 10, 13, 0, 6, 9, 8, 7, 4, 15, 14, 3, 11, 5, 2, 12,
7, 13, 14, 3, 0, 6, 9, 10, 1, 2, 8, 5, 11, 12, 4, 15,
13, 8, 11, 5, 6, 15, 0, 3, 4, 7, 2, 12, 1, 10, 14, 9,
10, 6, 9, 0, 12, 11, 7, 13, 15, 1, 3, 14, 5, 2, 8, 4,
3, 15, 0, 6, 10, 1, 13, 8, 9, 4, 5, 11, 12, 7, 2, 14,
2, 12, 4, 1, 7, 10, 11, 6, 8, 5, 3, 15, 13, 0, 14, 9,
14, 11, 2, 12, 4, 7, 13, 1, 5, 0, 15, 10, 3, 9, 8, 6,
4, 2, 1, 11, 10, 13, 7, 8, 15, 9, 12, 5, 6, 3, 0, 14,
11, 8, 12, 7, 1, 14, 2, 13, 6, 15, 0, 9, 10, 4, 5, 3,
12, 1, 10, 15, 9, 2, 6, 8, 0, 13, 3, 4, 14, 7, 5, 11,
10, 15, 4, 2, 7, 12, 9, 5, 6, 1, 13, 14, 0, 11, 3, 8,
9, 14, 15, 5, 2, 8, 12, 3, 7, 0, 4, 10, 1, 13, 11, 6,
4, 3, 2, 12, 9, 5, 15, 10, 11, 14, 1, 7, 6, 0, 8, 13,
4, 11, 2, 14, 15, 0, 8, 13, 3, 12, 9, 7, 5, 10, 6, 1,
13, 0, 11, 7, 4, 9, 1, 10, 14, 3, 5, 12, 2, 15, 8, 6,
1, 4, 11, 13, 12, 3, 7, 14, 10, 15, 6, 8, 0, 5, 9, 2,
6, 11, 13, 8, 1, 4, 10, 7, 9, 5, 0, 15, 14, 2, 3, 12,
13, 2, 8, 4, 6, 15, 11, 1, 10, 9, 3, 14, 5, 0, 12, 7,
1, 15, 13, 8, 10, 3, 7, 4, 12, 5, 6, 11, 0, 14, 9, 2,
7, 11, 4, 1, 9, 12, 14, 2, 0, 6, 10, 13, 15, 3, 5, 8,
2, 1, 14, 7, 4, 10, 8, 13, 15, 12, 9, 0, 3, 5, 6, 11
/* 32-bit permutation function P used on the output of the S-boxes */
/* End of DES-defined tables */
/* Lookup tables initialized once only at startup by desinit() */
static long (*sp
)[64]; /* Combined S and P boxes */
static char (*iperm
)[16][8]; /* Initial and final permutations */
static char (*fperm
)[16][8];
/* 8 6-bit subkeys for each of 16 rounds, initialized by setkey() */
/* bit 0 is left-most in byte */
0200,0100,040,020,010,04,02,01
static int nibblebit
[] = {
/* Allocate space and initialize DES lookup arrays
* mode == 0: standard Data Encryption Algorithm
* mode == 1: DEA without initial and final permutations for speed
* mode == 2: DEA without permutations and with 128-byte key (completely
* independent subkeys for each round)
/* Already initialized */
if((sp
= (long (*)[64])malloc(sizeof(long) * 8 * 64)) == NULL
){
kn
= (char (*)[8])malloc(sizeof(char) * 8 * 16);
if(mode
== 1 || mode
== 2) /* No permutations */
iperm
= (char (*)[16][8])malloc(sizeof(char) * 16 * 16 * 8);
fperm
= (char (*)[16][8])malloc(sizeof(char) * 16 * 16 * 8);
/* Free up storage used by DES */
return; /* Already done */
/* Set key (initialize key schedule array) */
char *key
; /* 64 bits (will use only 56) */
char pc1m
[56]; /* place to modify pc1 into */
char pcr
[56]; /* place to rotate pc1 into */
/* In mode 2, the 128 bytes of subkey are set directly from the
* user's key, allowing him to use completely independent
* subkeys for each round. Note that the user MUST specify a
* I would like to think that this technique gives the NSA a real
* headache, but I'm not THAT naive.
memset((char *)kn
,0,16*8);
for (j
=0; j
<56; j
++) { /* convert pc1 to bits of key */
l
=pc1
[j
]-1; /* integer bit location */
m
= l
& 07; /* find bit */
pc1m
[j
]=(key
[l
>>3] & /* find which key byte l is in */
bytebit
[m
]) /* and which bit of that byte */
? 1 : 0; /* and store 1-bit result */
for (i
=0; i
<16; i
++) { /* key chunk for each iteration */
for (j
=0; j
<56; j
++) /* rotate pc1 the right amount */
pcr
[j
] = pc1m
[(l
=j
+totrot
[i
])<(j
<28? 28 : 56) ? l
: l
-28];
/* rotate left and right halves independently */
for (j
=0; j
<48; j
++){ /* select bits individually */
/* check bit that goes to kn[j] */
/* mask it in if it's there */
kn
[i
][j
/6] |= bytebit
[l
] >> 2;
/* In-place encryption of 64-bit block */
register long left
,right
;
long work
[2]; /* Working data storage */
permute(block
,iperm
,(char *)work
); /* Initial Permutation */
#if BYTE_ORDER == LITTLE_ENDIAN
left
= byteswap(work
[0]);
right
= byteswap(work
[1]);
* The rounds are numbered from 0 to 15. On even rounds
* the right half is fed to f() and the result exclusive-ORs
* the left half; on odd rounds the reverse is done.
/* Left/right half swap, plus byte swap if little-endian */
#if BYTE_ORDER == LITTLE_ENDIAN
work
[1] = byteswap(left
);
work
[0] = byteswap(right
);
permute((char *)work
,fperm
,block
); /* Inverse initial permutation */
/* In-place decryption of 64-bit block. This function is the mirror
* image of encryption; exactly the same steps are taken, but in
register long left
,right
;
long work
[2]; /* Working data storage */
permute(block
,iperm
,(char *)work
); /* Initial permutation */
/* Left/right half swap, plus byte swap if little-endian */
#if BYTE_ORDER == LITTLE_ENDIAN
right
= byteswap(work
[0]);
left
= byteswap(work
[1]);
/* Do the 16 rounds in reverse order.
* The rounds are numbered from 15 to 0. On even rounds
* the right half is fed to f() and the result exclusive-ORs
* the left half; on odd rounds the reverse is done.
#if BYTE_ORDER == LITTLE_ENDIAN
work
[0] = byteswap(left
);
work
[1] = byteswap(right
);
permute((char *)work
,fperm
,block
); /* Inverse initial permutation */
/* Permute inblock with perm */
permute(inblock
,perm
,outblock
)
char *inblock
, *outblock
; /* result into outblock,64 bits */
char perm
[16][16][8]; /* 2K bytes defining perm. */
register char *ib
, *ob
; /* ptr to input or output block */
/* No permutation, just copy */
memcpy(outblock
,inblock
,8);
for (j
= 0; j
< 16; j
+= 2, ib
++) { /* for each input nibble */
p
= perm
[j
][(*ib
>> 4) & 0xf];
q
= perm
[j
+ 1][*ib
& 0xf];
/* and each output byte, OR the masks together */
/* The nonlinear function f(r,k), the heart of DES */
register long r
; /* 32 bits */
register char *subkey
; /* 48-bit key for this round */
printf("f(%08lx, %02x %02x %02x %02x %02x %02x %02x %02x) = ",
subkey
[0], subkey
[1], subkey
[2],
subkey
[3], subkey
[4], subkey
[5],
/* Run E(R) ^ K through the combined S & P boxes.
* This code takes advantage of a convenient regularity in
* E, namely that each group of 6 bits in E(R) feeding
* a single S-box is a contiguous segment of R.
/* Compute E(R) for each block of 6 bits, and run thru boxes */
er
= ((int)r
<< 1) | ((r
& 0x80000000) ? 1 : 0);
rval
= spp
[(er
^ *subkey
--) & 0x3f];
rt
= (unsigned long)r
>> 3;
rval
|= spp
[((int)rt
^ *subkey
--) & 0x3f];
rval
|= spp
[((int)rt
^ *subkey
--) & 0x3f];
rval
|= spp
[((int)rt
^ *subkey
--) & 0x3f];
rval
|= spp
[((int)rt
^ *subkey
--) & 0x3f];
rval
|= spp
[((int)rt
^ *subkey
--) & 0x3f];
rval
|= spp
[((int)rt
^ *subkey
--) & 0x3f];
rval
|= spp
[((int)rt
^ *subkey
) & 0x3f];
/* initialize a perm array */
char perm
[16][16][8]; /* 64-bit, either init or final */
/* Clear the permutation array */
memset((char *)perm
,0,16*16*8);
for (i
=0; i
<16; i
++) /* each input nibble position */
for (j
= 0; j
< 16; j
++)/* each possible input nibble */
for (k
= 0; k
< 64; k
++)/* each output bit position */
{ l
= p
[k
] - 1; /* where does this bit come from*/
if ((l
>> 2) != i
) /* does it come from input posn?*/
continue; /* if not, bit k is 0 */
if (!(j
& nibblebit
[l
& 3]))
continue; /* any such bit in input? */
m
= k
& 07; /* which bit is this in the byte*/
perm
[i
][j
][k
>>3] |= bytebit
[m
];
/* Initialize the lookup table for the combined S and P boxes */
/* Compute pbox, the inverse of p32i.
* This is easier to work with
for(s
= 0; s
< 8; s
++){ /* For each S-box */
for(i
=0; i
<64; i
++){ /* For each possible input */
/* The row number is formed from the first and last
* bits; the column number is from the middle 4
rowcol
= (i
& 32) | ((i
& 1) ? 16 : 0) | ((i
>> 1) & 0xf);
for(j
=0;j
<4;j
++){ /* For each output bit */
if(si
[s
][rowcol
] & (8 >> j
)){
val
|= 1L << (31 - pbox
[4*s
+ j
]);
printf("sp[%d][%2d] = %08lx\n",s
,i
,sp
[s
][i
]);
#if BYTE_ORDER == LITTLE_ENDIAN