From ebaeedead1062335aa18e7093f95b8e93e294a7e Mon Sep 17 00:00:00 2001
From: Leonid Evdokimov <leon@darkk.net.ru>
Date: Fri, 11 Feb 2011 01:28:51 +0200
Subject: [PATCH] Improve nonce generation: srand() should be called only
 during startup.

---
 http-connect.c | 1 -
 http-relay.c   | 1 -
 main.c         | 9 +++++++++
 3 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/http-connect.c b/http-connect.c
index 6df1a03..ce34c94 100644
--- a/http-connect.c
+++ b/http-connect.c
@@ -210,7 +210,6 @@ static struct evbuffer *httpc_mkconnect(redsocks_client *client)
 
 			/* prepare an random string for cnounce */
 			char cnounce[17];
-			srand(time(0));
 			for (int i = 0; i < 16; i += 4)
 				sprintf(cnounce + i, "%02x", rand() & 65535);
 
diff --git a/http-relay.c b/http-relay.c
index 7ad2c67..33c90c7 100644
--- a/http-relay.c
+++ b/http-relay.c
@@ -321,7 +321,6 @@ static void httpr_relay_write_cb(struct bufferevent *buffev, void *_arg)
 
 				/* prepare an random string for cnounce */
 				char cnounce[17];
-				srand(time(0));
 				for (int i = 0; i < 16; i += 4)
 					sprintf(cnounce + i, "%04x", rand() & 65535);
 
diff --git a/main.c b/main.c
index b8fb5a0..e375df8 100644
--- a/main.c
+++ b/main.c
@@ -46,6 +46,14 @@ static void terminate(int sig, short what, void *_arg)
 		log_error(LOG_WARNING, "event_loopbreak");
 }
 
+static void red_srand()
+{
+	struct timeval tv;
+	gettimeofday(&tv, NULL);
+	// using tv_usec is a bit less predictable than tv_sec
+	srand(tv.tv_sec*1000000+tv.tv_usec);
+}
+
 int main(int argc, char **argv)
 {
 	int error;
@@ -56,6 +64,7 @@ int main(int argc, char **argv)
 	int opt;
 	int i;
 
+	red_srand();
 	while ((opt = getopt(argc, argv, "tc:p:")) != -1) {
 		switch (opt) {
 		case 't':