From bfebb51a4223d7595ba402e059cc1067fd9a460d Mon Sep 17 00:00:00 2001
From: Zhi Guan <guanzhi1980@gmail.com>
Date: Mon, 15 Jun 2020 15:48:00 +0800
Subject: [PATCH] add javascript rng

---
 js/rand.js | 66 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 66 insertions(+)
 create mode 100644 js/rand.js

diff --git a/js/rand.js b/js/rand.js
new file mode 100644
index 00000000..2a89391f
--- /dev/null
+++ b/js/rand.js
@@ -0,0 +1,66 @@
+/*
+ * Copyright (c) 2014 - 2020 The GmSSL Project.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * 3. All advertising materials mentioning features or use of this
+ *    software must display the following acknowledgment:
+ *    "This product includes software developed by the GmSSL Project.
+ *    (http://gmssl.org/)"
+ *
+ * 4. The name "GmSSL Project" must not be used to endorse or promote
+ *    products derived from this software without prior written
+ *    permission. For written permission, please contact
+ *    guanzhi1980@gmail.com.
+ *
+ * 5. Products derived from this software may not be called "GmSSL"
+ *    nor may "GmSSL" appear in their names without prior written
+ *    permission of the GmSSL Project.
+ *
+ * 6. Redistributions of any form whatsoever must retain the following
+ *    acknowledgment:
+ *    "This product includes software developed by the GmSSL Project
+ *    (http://gmssl.org/)"
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE GmSSL PROJECT ``AS IS'' AND ANY
+ * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE GmSSL PROJECT OR
+ * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+function rand_bytes(data, len) {
+	var buf = new Uint8Array(len);
+	window.crypto.getRandomValues(buf);
+	for (var i = 0; i < len; i++) {
+		data[i] = buf[i];
+		buf[i] = 0;
+	}
+	delete buf;
+}
+
+function bn_rand_range(a, n) {
+	var t = new Uint16Array(16);
+	do {
+		window.crypto.getRandomValues(t);
+	} while (bn_cmp(t, n) >= 0);
+	bn_copy(a, t);
+	bn_free(t);
+}