mirror of https://github.com/mabam/CAP.git
525 lines
13 KiB
C
525 lines
13 KiB
C
#ifdef __alpha
|
|
#define long int
|
|
#endif /* __alpha */
|
|
|
|
/*
|
|
* Sofware DES functions
|
|
* written 12 Dec 1986 by Phil Karn, KA9Q; large sections adapted from
|
|
* the 1977 public-domain program by Jim Gillogly
|
|
*/
|
|
|
|
#define NULL 0
|
|
|
|
#ifdef BYTESWAPPED
|
|
unsigned long byteswap();
|
|
#endif BYTESWAPPED
|
|
|
|
/* Tables defined in the Data Encryption Standard documents */
|
|
|
|
/* initial permutation IP */
|
|
static char 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 */
|
|
static char fp[] = {
|
|
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
|
|
*/
|
|
#ifdef notdef
|
|
static char ei[] = {
|
|
32, 1, 2, 3, 4, 5,
|
|
4, 5, 6, 7, 8, 9,
|
|
8, 9, 10, 11, 12, 13,
|
|
12, 13, 14, 15, 16, 17,
|
|
16, 17, 18, 19, 20, 21,
|
|
20, 21, 22, 23, 24, 25,
|
|
24, 25, 26, 27, 28, 29,
|
|
28, 29, 30, 31, 32, 1
|
|
};
|
|
#endif
|
|
|
|
/* permuted choice table (key) */
|
|
static char pc1[] = {
|
|
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,
|
|
21, 13, 5, 28, 20, 12, 4
|
|
};
|
|
|
|
/* number left rotations of pc1 */
|
|
static char totrot[] = {
|
|
1,2,4,6,8,10,12,14,15,17,19,21,23,25,27,28
|
|
};
|
|
|
|
/* permuted choice key (table) */
|
|
static char pc2[] = {
|
|
14, 17, 11, 24, 1, 5,
|
|
3, 28, 15, 6, 21, 10,
|
|
23, 19, 12, 4, 26, 8,
|
|
16, 7, 27, 20, 13, 2,
|
|
41, 52, 31, 37, 47, 55,
|
|
30, 40, 51, 45, 33, 48,
|
|
44, 49, 39, 56, 34, 53,
|
|
46, 42, 50, 36, 29, 32
|
|
};
|
|
|
|
/* The (in)famous S-boxes */
|
|
static char si[8][64] = {
|
|
/* S1 */
|
|
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,
|
|
|
|
/* S2 */
|
|
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,
|
|
|
|
/* S3 */
|
|
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,
|
|
|
|
/* S4 */
|
|
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,
|
|
|
|
/* S5 */
|
|
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,
|
|
|
|
/* S6 */
|
|
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,
|
|
|
|
/* S7 */
|
|
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,
|
|
|
|
/* S8 */
|
|
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 */
|
|
static char p32i[] = {
|
|
16, 7, 20, 21,
|
|
29, 12, 28, 17,
|
|
1, 15, 23, 26,
|
|
5, 18, 31, 10,
|
|
2, 8, 24, 14,
|
|
32, 27, 3, 9,
|
|
19, 13, 30, 6,
|
|
22, 11, 4, 25
|
|
};
|
|
/* 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 dessetkey() */
|
|
static unsigned char (*kn)[8];
|
|
|
|
/* bit 0 is left-most in byte */
|
|
static int bytebit[] = {
|
|
0200,0100,040,020,010,04,02,01
|
|
};
|
|
|
|
static int nibblebit[] = {
|
|
010,04,02,01
|
|
};
|
|
static int desmode;
|
|
static permute(), round(), perminit(), spinit();
|
|
static long f();
|
|
|
|
/* 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)
|
|
*/
|
|
desinit(mode)
|
|
int mode;
|
|
{
|
|
char *malloc();
|
|
|
|
if(sp != NULL){
|
|
/* Already initialized */
|
|
return 0;
|
|
}
|
|
desmode = mode;
|
|
|
|
if((sp = (long (*)[64])malloc(sizeof(long) * 8 * 64)) == NULL){
|
|
return -1;
|
|
}
|
|
spinit();
|
|
kn = (unsigned char (*)[8])malloc(sizeof(char) * 8 * 16);
|
|
if(kn == NULL){
|
|
free((char *)sp);
|
|
return -1;
|
|
}
|
|
if(mode == 1 || mode == 2) /* No permutations */
|
|
return 0;
|
|
|
|
iperm = (char (*)[16][8])malloc(sizeof(char) * 16 * 16 * 8);
|
|
if(iperm == NULL){
|
|
free((char *)sp);
|
|
free((char *)kn);
|
|
return -1;
|
|
}
|
|
perminit(iperm,ip);
|
|
|
|
fperm = (char (*)[16][8])malloc(sizeof(char) * 16 * 16 * 8);
|
|
if(fperm == NULL){
|
|
free((char *)sp);
|
|
free((char *)kn);
|
|
free((char *)iperm);
|
|
return -1;
|
|
}
|
|
perminit(fperm,fp);
|
|
|
|
return 0;
|
|
}
|
|
/* Free up storage used by DES */
|
|
desdone()
|
|
{
|
|
if(sp == NULL)
|
|
return; /* Already done */
|
|
|
|
free((char *)sp);
|
|
free((char *)kn);
|
|
if(iperm != NULL)
|
|
free((char *)iperm);
|
|
if(fperm != NULL)
|
|
free((char *)fperm);
|
|
|
|
sp = NULL;
|
|
iperm = NULL;
|
|
fperm = NULL;
|
|
kn = NULL;
|
|
}
|
|
/* Set key (initialize key schedule array) */
|
|
dessetkey(key)
|
|
char *key; /* 64 bits (will use only 56) */
|
|
{
|
|
char pc1m[56]; /* place to modify pc1 into */
|
|
char pcr[56]; /* place to rotate pc1 into */
|
|
register int i,j,l;
|
|
int m;
|
|
|
|
/* 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
|
|
* full 128 bytes.
|
|
*
|
|
* I would like to think that this technique gives the NSA a real
|
|
* headache, but I'm not THAT naive.
|
|
*/
|
|
if(desmode == 2){
|
|
for(i=0;i<16;i++)
|
|
for(j=0;j<8;j++)
|
|
kn[i][j] = *key++;
|
|
return;
|
|
}
|
|
/* Clear key schedule */
|
|
for (i=0; i<16; i++)
|
|
for (j=0; j<8; j++)
|
|
kn[i][j]=0;
|
|
|
|
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] */
|
|
if (pcr[pc2[j]-1]){
|
|
/* mask it in if it's there */
|
|
l= j % 6;
|
|
kn[i][j/6] |= bytebit[l] >> 2;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
/* In-place encryption of 64-bit block */
|
|
endes(block)
|
|
char *block;
|
|
{
|
|
register int i;
|
|
unsigned long work[2]; /* Working data storage */
|
|
long tmp;
|
|
|
|
permute(block,iperm,(char *)work); /* Initial Permutation */
|
|
#ifdef BYTESWAPPED
|
|
work[0] = byteswap(work[0]);
|
|
work[1] = byteswap(work[1]);
|
|
#endif BYTESWAPPED
|
|
|
|
/* Do the 16 rounds */
|
|
for (i=0; i<16; i++)
|
|
round(i,work);
|
|
|
|
/* Left/right half swap */
|
|
tmp = work[0];
|
|
work[0] = work[1];
|
|
work[1] = tmp;
|
|
|
|
#ifdef BYTESWAPPED
|
|
work[0] = byteswap(work[0]);
|
|
work[1] = byteswap(work[1]);
|
|
#endif BYTESWAPPED
|
|
permute((char *)work,fperm,block); /* Inverse initial permutation */
|
|
}
|
|
/* In-place decryption of 64-bit block */
|
|
dedes(block)
|
|
char *block;
|
|
{
|
|
register int i;
|
|
unsigned long work[2]; /* Working data storage */
|
|
long tmp;
|
|
|
|
permute(block,iperm,(char *)work); /* Initial permutation */
|
|
|
|
#ifdef BYTESWAPPED
|
|
work[0] = byteswap(work[0]);
|
|
work[1] = byteswap(work[1]);
|
|
#endif BYTESWAPPED
|
|
|
|
/* Left/right half swap */
|
|
tmp = work[0];
|
|
work[0] = work[1];
|
|
work[1] = tmp;
|
|
|
|
/* Do the 16 rounds in reverse order */
|
|
for (i=15; i >= 0; i--)
|
|
round(i,work);
|
|
|
|
#ifdef BYTESWAPPED
|
|
work[0] = byteswap(work[0]);
|
|
work[1] = byteswap(work[1]);
|
|
#endif BYTESWAPPED
|
|
|
|
permute((char *)work,fperm,block); /* Inverse initial permutation */
|
|
}
|
|
|
|
/* Permute inblock with perm */
|
|
static
|
|
permute(inblock,perm,outblock)
|
|
char *inblock, *outblock; /* result into outblock,64 bits */
|
|
char perm[16][16][8]; /* 2K bytes defining perm. */
|
|
{
|
|
register int i,j;
|
|
register char *ib, *ob; /* ptr to input or output block */
|
|
register char *p, *q;
|
|
|
|
if(perm == NULL){
|
|
/* No permutation, just copy */
|
|
for(i=8; i!=0; i--)
|
|
*outblock++ = *inblock++;
|
|
return;
|
|
}
|
|
/* Clear output block */
|
|
for (i=8, ob = outblock; i != 0; i--)
|
|
*ob++ = 0;
|
|
|
|
ib = inblock;
|
|
for (j = 0; j < 16; j += 2, ib++) { /* for each input nibble */
|
|
ob = outblock;
|
|
p = perm[j][(*ib >> 4) & 017];
|
|
q = perm[j + 1][*ib & 017];
|
|
for (i = 8; i != 0; i--){ /* and each output byte */
|
|
*ob++ |= *p++ | *q++; /* OR the masks together*/
|
|
}
|
|
}
|
|
}
|
|
|
|
/* Do one DES cipher round */
|
|
static
|
|
round(num,block)
|
|
int num; /* i.e. the num-th one */
|
|
unsigned long *block;
|
|
{
|
|
/* 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.
|
|
*/
|
|
if(num & 1){
|
|
block[1] ^= f(block[0],kn[num]);
|
|
} else {
|
|
block[0] ^= f(block[1],kn[num]);
|
|
}
|
|
}
|
|
/* The nonlinear function f(r,k), the heart of DES */
|
|
static
|
|
long
|
|
f(r,subkey)
|
|
unsigned long r; /* 32 bits */
|
|
unsigned char subkey[8]; /* 48-bit key for this round */
|
|
{
|
|
register unsigned long rval,rt;
|
|
#ifdef TRACE
|
|
unsigned char *cp;
|
|
int i;
|
|
|
|
printf("f(%08lx, %02x %02x %02x %02x %02x %02x %02x %02x) = ",
|
|
r,
|
|
subkey[0], subkey[1], subkey[2],
|
|
subkey[3], subkey[4], subkey[5],
|
|
subkey[6], subkey[7]);
|
|
#endif TRACE
|
|
/* 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.
|
|
*/
|
|
rt = (r >> 1) | ((r & 1) ? 0x80000000 : 0);
|
|
rval = 0;
|
|
rval |= sp[0][((rt >> 26) ^ *subkey++) & 0x3f];
|
|
rval |= sp[1][((rt >> 22) ^ *subkey++) & 0x3f];
|
|
rval |= sp[2][((rt >> 18) ^ *subkey++) & 0x3f];
|
|
rval |= sp[3][((rt >> 14) ^ *subkey++) & 0x3f];
|
|
rval |= sp[4][((rt >> 10) ^ *subkey++) & 0x3f];
|
|
rval |= sp[5][((rt >> 6) ^ *subkey++) & 0x3f];
|
|
rval |= sp[6][((rt >> 2) ^ *subkey++) & 0x3f];
|
|
rt = (r << 1) | ((r & 0x80000000) ? 1 : 0);
|
|
rval |= sp[7][(rt ^ *subkey) & 0x3f];
|
|
#ifdef TRACE
|
|
printf(" %08lx\n",rval);
|
|
#endif TRACE
|
|
return rval;
|
|
}
|
|
/* initialize a perm array */
|
|
static
|
|
perminit(perm,p)
|
|
char perm[16][16][8]; /* 64-bit, either init or final */
|
|
char p[64];
|
|
{
|
|
register int l, j, k;
|
|
int i,m;
|
|
|
|
/* Clear the permutation array */
|
|
for (i=0; i<16; i++)
|
|
for (j=0; j<16; j++)
|
|
for (k=0; k<8; k++)
|
|
perm[i][j][k]=0;
|
|
|
|
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 */
|
|
static int
|
|
spinit()
|
|
{
|
|
char pbox[32];
|
|
int p,i,s,j,rowcol;
|
|
long val;
|
|
|
|
/* Compute pbox, the inverse of p32i.
|
|
* This is easier to work with
|
|
*/
|
|
for(p=0;p<32;p++){
|
|
for(i=0;i<32;i++){
|
|
if(p32i[i]-1 == p){
|
|
pbox[p] = i;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
for(s = 0; s < 8; s++){ /* For each S-box */
|
|
for(i=0; i<64; i++){ /* For each possible input */
|
|
val = 0;
|
|
/* 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]);
|
|
}
|
|
}
|
|
sp[s][i] = val;
|
|
|
|
#ifdef DEBUG
|
|
printf("sp[%d][%2d] = %08lx\n",s,i,sp[s][i]);
|
|
#endif DEBUG
|
|
}
|
|
}
|
|
}
|
|
#ifdef BYTESWAPPED
|
|
/* Byte swap a long */
|
|
static
|
|
unsigned long
|
|
byteswap(x)
|
|
unsigned long x;
|
|
{
|
|
register char *cp,tmp;
|
|
|
|
cp = (char *)&x;
|
|
tmp = cp[3];
|
|
cp[3] = cp[0];
|
|
cp[0] = tmp;
|
|
|
|
tmp = cp[2];
|
|
cp[2] = cp[1];
|
|
cp[1] = tmp;
|
|
|
|
return x;
|
|
}
|
|
#endif BYTESWAPPED
|