passwd: shrink by ~10 bytes, use PRNG instead of usleep.

1 files changed, 10 insertions, 17 deletions

diff --git a/loginutils/passwd.c b/loginutils/passwd.c
index 1f488290a..a062596b4 100644
--- a/loginutils/passwd.c
+++ b/loginutils/passwd.c
@@ -5,7 +5,6 @@
 
 #include "busybox.h"
 #include <syslog.h>
-#include <sys/times.h> /* times() */
 
 
 static void nuke_str(char *str)
@@ -16,7 +15,8 @@ static void nuke_str(char *str)
 
 static int i64c(int i)
 {
-        if (i <= 0)
+        i &= 0x3f;
+        if (i == 0)
                 return '.';
         if (i == 1)
                 return '/';
@@ -30,23 +30,16 @@ static int i64c(int i)
 
 static void crypt_make_salt(char *p, int cnt)
 {
-#if !defined(__GLIBC__)
-        struct tms t;
-#define TIMES times(&t)
-#else
-/* glibc allows for times(NULL) a-la time() */
-#define TIMES times(NULL)
-#endif
-        unsigned long x = x; /* it's pointless to initialize it anyway :) */
+        unsigned x = x; /* it's pointless to initialize it anyway :) */
 
-        x += getpid();
+        x += getpid() + time(NULL) + clock();
         do {
-        /* clock() and times() variability is different between systems */
-        /* hopefully at least one is good enough */
-                x += time(NULL) + clock() + TIMES;
-                *p++ = i64c(((x >> 18) ^ (x >> 6)) & 0x3f);
-                *p++ = i64c(((x >> 12) ^ x) & 0x3f);
-                usleep(100); /* or else time() etc won't change */
+                /* x = (x*1664525 + 1013904223) mod 2^32 generator is lame
+                 * (low-order bit is not "random", etc...),
+                 * but for our purposes it is good enough */
+                x = x*1664525 + 1013904223;
+                *p++ = i64c(x >> 16);
+                *p++ = i64c(x >> 22);
         } while (--cnt);
         *p = '\0';
 }