1#include <stdint.h>
2#include <stdlib.h>
3#include <unistd.h>
4
5struct expanded_key {
6        uint32_t l[16], r[16];
7};
8
9void __des_setkey(const unsigned char *key, struct expanded_key *ekey);
10void __do_des(uint32_t l_in, uint32_t r_in,
11    uint32_t *l_out, uint32_t *r_out,
12    uint32_t count, uint32_t saltbits, const struct expanded_key *ekey);
13
14
15static struct expanded_key __encrypt_key;
16
17void setkey(const char *key)
18{
19	unsigned char bkey[8];
20	int i, j;
21
22	for (i = 0; i < 8; i++) {
23		bkey[i] = 0;
24		for (j = 7; j >= 0; j--, key++)
25			bkey[i] |= (uint32_t)(*key & 1) << j;
26	}
27
28	__des_setkey(bkey, &__encrypt_key);
29}
30
31void encrypt(char *block, int edflag)
32{
33	struct expanded_key decrypt_key, *key;
34	uint32_t b[2];
35	int i, j;
36	char *p;
37
38	p = block;
39	for (i = 0; i < 2; i++) {
40		b[i] = 0;
41		for (j = 31; j >= 0; j--, p++)
42			b[i] |= (uint32_t)(*p & 1) << j;
43	}
44
45	key = &__encrypt_key;
46	if (edflag) {
47		key = &decrypt_key;
48		for (i = 0; i < 16; i++) {
49			decrypt_key.l[i] = __encrypt_key.l[15-i];
50			decrypt_key.r[i] = __encrypt_key.r[15-i];
51		}
52	}
53
54	__do_des(b[0], b[1], b, b + 1, 1, 0, key);
55
56	p = block;
57	for (i = 0; i < 2; i++)
58		for (j = 31; j >= 0; j--)
59			*p++ = b[i]>>j & 1;
60}
61