From 60d3db8e6bafa21d807ea31690eddf44bb7ef020 Mon Sep 17 00:00:00 2001
From: wkj <devnull@localhost>
Date: Wed, 21 Apr 2004 03:06:03 +0000
Subject: Try to gather entropy from /dev/random.

---
 src/lib9/truerand.c | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)
 create mode 100644 src/lib9/truerand.c

(limited to 'src')

diff --git a/src/lib9/truerand.c b/src/lib9/truerand.c
new file mode 100644
index 00000000..aaf10f0a
--- /dev/null
+++ b/src/lib9/truerand.c
@@ -0,0 +1,21 @@
+#include <u.h>
+#include <libc.h>
+
+ulong
+truerand(void)
+{
+	int i, n;
+	uchar buf[sizeof(ulong)];
+	static int randfd = -1;
+
+	if(randfd < 0){
+		randfd = open("/dev/random", OREAD);
+		fcntl(randfd, F_SETFD, FD_CLOEXEC);
+	}
+	if(randfd < 0)
+		sysfatal("can't open /dev/random: %r");
+	for(i=0; i<sizeof(buf); i += n)
+		if((n = readn(randfd, buf+i, sizeof(buf)-i)) < 0)
+			sysfatal("can't read /dev/random: %r");
+	return *((ulong*)buf);
+}
-- 
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