passwd: added comment
diff --git a/loginutils/passwd.c b/loginutils/passwd.c
index a062596..c28e9b8 100644
--- a/loginutils/passwd.c
+++ b/loginutils/passwd.c
@@ -34,10 +34,15 @@
x += getpid() + time(NULL) + clock();
do {
- /* x = (x*1664525 + 1013904223) mod 2^32 generator is lame
+ /* x = (x*1664525 + 1013904223) % 2^32 generator is lame
* (low-order bit is not "random", etc...),
* but for our purposes it is good enough */
x = x*1664525 + 1013904223;
+ /* BTW, Park and Miller's "minimal standard generator" is
+ * x = x*16807 % ((2^31)-1)
+ * It has no problem with visibly alternating lowest bit
+ * but is also weak in cryptographic sense + needs div,
+ * which needs more code (and slower) on many CPUs */
*p++ = i64c(x >> 16);
*p++ = i64c(x >> 22);
} while (--cnt);