From: Denis Vlasenko <vda.linux@googlemail.com>
Date: Tue, 12 Dec 2006 17:14:56 +0000 (-0000)
Subject: passwd: added comment
X-Git-Tag: 1_4_0~258
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=db2b52425dced7665cc33cc9fb6ade688fcbce4a;p=platform%2Fupstream%2Fbusybox.git

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 @@ static void crypt_make_salt(char *p, int cnt)
 
 	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);