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#include "DES_std.h"
#include "DES_bs.h"
DES_bs_combined DES_bs_all;
int DES_bs_mem_saving = 0;
extern void DES_bs_body();
void DES_bs_init()
{
int index, bit;
for (index = 0; index < 0x300; index++) {
bit = DES_K_bits[index];
bit -= bit >> 3;
DES_bs_all.Kp[index] = &DES_bs_all.K[55 - bit];
}
}
void DES_bs_set_salt(ARCH_WORD salt)
{
register int src, dst;
register ARCH_WORD mask;
mask = 1;
for (dst = 0; dst < 48; dst++) {
if (dst == 24) mask = 1;
if (salt & mask) {
if (dst < 24) src = dst + 24; else src = dst - 24;
} else src = dst;
DES_bs_all.E[dst] = &DES_bs_all.B[DES_E[src]];
DES_bs_all.E[dst + 48] = &DES_bs_all.B[DES_E[src] + 32];
mask <<= 1;
}
}
void DES_bs_clear_keys()
{
memset(DES_bs_all.K, 0, sizeof(DES_bs_all.K));
}
void DES_bs_set_key(char *key, int index)
{
register char *ptr;
register int ofs, bit;
register ARCH_WORD value;
ofs = 56;
for (ptr = key; *ptr && ofs; ptr++) {
bit = (ofs -= 7);
value = *ptr & 0x7F;
do {
DES_bs_all.K[bit++] |= (value & 1) << index;
} while (value >>= 1);
}
}
void DES_bs_crypt(int count)
{
register int bit;
register ARCH_WORD R, L;
memset(DES_bs_all.B, 0, sizeof(DES_bs_all.B));
do {
DES_bs_body();
if (!--count) break;
for (bit = 0; bit < 32; bit++) {
R = DES_bs_all.B[bit];
L = DES_bs_all.B[bit + 32];
DES_bs_all.B[bit + 32] = R;
DES_bs_all.B[bit] = L;
}
} while (1);
}
ARCH_WORD *DES_bs_get_binary(char *ciphertext)
{
static ARCH_WORD out[64];
ARCH_WORD *raw;
int bit;
int index, shift;
int value;
raw = DES_raw_get_binary(ciphertext);
out[1] = out[0] = 0;
for (bit = 0; bit < 64; bit++) {
index = bit >> 4;
/* Swap L and R here instead of doing it one more time in DES_bs_crypt() */
index ^= 2;
/* Calculate the number of one of the 16 data bits in raw[index] */
shift = ((bit & 0xC) << 1) + (bit & 3) + 1;
/* Get the bit */
value = (raw[index] >> shift) & 1;
if (DES_bs_mem_saving)
/* Memory saving: pack the bits into two words */
out[bit >> 5] |= value << (bit & 0x1F);
else
/* We either set or clear all the bits in every word */
out[bit] = value ? ~(ARCH_WORD)0 : 0;
}
return out;
}
int DES_bs_binary_hash(ARCH_WORD *binary, int count)
{
int bit, result;
if (DES_bs_mem_saving)
return (int)*binary & ((1 << count) - 1);
result = 0;
for (bit = 0; bit < count; bit++)
if (binary[bit]) result |= 1 << bit;
return result;
}
int DES_bs_get_hash(int index, int count)
{
register int bit, result;
register ARCH_WORD mask;
mask = (ARCH_WORD)1 << index;
result = 0;
for (bit = 0; bit < count; bit++)
if (DES_bs_all.B[bit] & mask) result |= 1 << bit;
return result;
}
/*
* The trick I used here allows to compare one ciphertext against all the
* DES_bs_crypt() outputs in just O(log2(ARCH_BITS)) operations.
*/
int DES_bs_cmp_all(ARCH_WORD *binary, int count)
{
register int bit;
register ARCH_WORD mask;
mask = 0;
if (DES_bs_mem_saving)
for (bit = 0; bit < ((count < 32) ? count : 32); bit++) {
mask |= DES_bs_all.B[bit] ^
((binary[0] & (1 << bit)) ? ~(ARCH_WORD)0 : 0);
if (mask == ~(ARCH_WORD)0) return 0;
}
else
for (bit = 0; bit < count; bit++) {
mask |= DES_bs_all.B[bit] ^ binary[bit];
if (mask == ~(ARCH_WORD)0) return 0;
}
return 1;
}
int DES_bs_cmp_one(ARCH_WORD *binary, int count, int index)
{
register int bit;
register ARCH_WORD mask;
if (DES_bs_mem_saving) {
for (bit = 0; bit < count; bit++)
if (((DES_bs_all.B[bit] >> index) ^
Реферат опубликован: 25/10/2008