Worked with Samy Kamkar to improve LCG entropy.

php · Jan 8, 2010 · 00c5ca7 · 00c5ca7
1 parent 1cc974f
commit 00c5ca7
Showing 1 changed file with 6 additions and 1 deletion.
diff --git a/ext/standard/lcg.c b/ext/standard/lcg.c
@@ -78,7 +78,7 @@ static void lcg_seed(TSRMLS_D) /* {{{ */
 	struct timeval tv;
 
 	if (gettimeofday(&tv, NULL) == 0) {
-		LCG(s1) = tv.tv_sec ^ (~tv.tv_usec);
+		LCG(s1) = tv.tv_sec ^ (tv.tv_usec<<11);
 	} else {
 		LCG(s1) = 1;
 	}
@@ -88,6 +88,11 @@ static void lcg_seed(TSRMLS_D) /* {{{ */
 	LCG(s2) = (long) getpid();
 #endif
 
+	/* Add entropy to s2 by calling gettimeofday() again */
+	if (gettimeofday(&tv, NULL) == 0) {
+		LCG(s2) ^= (tv.tv_usec<<11);
+	}
+
 	LCG(seeded) = 1;
 }
 /* }}} */