There existed about a 1 in 4 billion chance that reading from /dev/urandom
authorMark Michelson <mmichelson@digium.com>
Wed, 21 Nov 2007 18:19:22 +0000 (18:19 +0000)
committerMark Michelson <mmichelson@digium.com>
Wed, 21 Nov 2007 18:19:22 +0000 (18:19 +0000)
would return LONG_MIN (1 in 9 quintillion if using 64-bit longs). Since there
is no positive equivalent of LONG_MIN, the result of labs() in this case is
unpredictable. This fixes that situation.

(closes issue #11336, reported and patched by sperreault)

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@89487 65c4cc65-6c06-0410-ace0-fbb531ad65f3

main/utils.c

index 8b3448f..83ab65a 100644 (file)
@@ -1140,7 +1140,7 @@ long int ast_random(void)
        if (dev_urandom_fd >= 0) {
                int read_res = read(dev_urandom_fd, &res, sizeof(res));
                if (read_res > 0)
-                       return labs(res);
+                       return res < 0 ? ~res : res;
        }
 #endif
 #ifdef linux