1/* vi: set sw=4 ts=4: */
2/*
3 * crypt_make_salt
4 *
5 * i64c was also put here, this is the only function that uses it.
6 *
7 * Lifted from loginutils/passwd.c by Thomas Lundquist <thomasez@zelow.no>
8 *
9 */
10
11#include "libbb.h"
12
13static int i64c(int i)
14{
15	i &= 0x3f;
16	if (i == 0)
17		return '.';
18	if (i == 1)
19		return '/';
20	if (i < 12)
21		return ('0' - 2 + i);
22	if (i < 38)
23		return ('A' - 12 + i);
24	return ('a' - 38 + i);
25}
26
27int crypt_make_salt(char *p, int cnt, int x)
28{
29	x += getpid() + time(NULL);
30	do {
31		/* x = (x*1664525 + 1013904223) % 2^32 generator is lame
32		 * (low-order bit is not "random", etc...),
33		 * but for our purposes it is good enough */
34		x = x*1664525 + 1013904223;
35		/* BTW, Park and Miller's "minimal standard generator" is
36		 * x = x*16807 % ((2^31)-1)
37		 * It has no problem with visibly alternating lowest bit
38		 * but is also weak in cryptographic sense + needs div,
39		 * which needs more code (and slower) on many CPUs */
40		*p++ = i64c(x >> 16);
41		*p++ = i64c(x >> 22);
42	} while (--cnt);
43	*p = '\0';
44	return x;
45}
46