From 6e4d243897cdaefde0ccca2a0e65bb45e4c992f9 Mon Sep 17 00:00:00 2001
From: Andrey Antukh <niwi@niwi.nz>
Date: Sun, 24 Apr 2016 21:49:14 +0300
Subject: [PATCH] Add uuid generation functions that uses high quality RNG.

---
 vendor/uuid/core.cljs | 25 +++++++++++++++++++++++
 vendor/uuid/impl.js   | 47 +++++++++++++++++++++++++++++++++++++++++++
 vendor/uuid/rng.js    | 44 ++++++++++++++++++++++++++++++++++++++++
 3 files changed, 116 insertions(+)
 create mode 100644 vendor/uuid/core.cljs
 create mode 100644 vendor/uuid/impl.js
 create mode 100644 vendor/uuid/rng.js

diff --git a/vendor/uuid/core.cljs b/vendor/uuid/core.cljs
new file mode 100644
index 000000000..d81b5df17
--- /dev/null
+++ b/vendor/uuid/core.cljs
@@ -0,0 +1,25 @@
+;; This Source Code Form is subject to the terms of the Mozilla Public
+;; License, v. 2.0. If a copy of the MPL was not distributed with this
+;; file, You can obtain one at http://mozilla.org/MPL/2.0/.
+;;
+;; Copyright (c) 2016 Andrey Antukh <niwi@niwi.nz>
+
+(ns uuid.core
+  "Provides a UUID v4 uuid generation.
+
+  In difference with builtin `random-uuid` function this
+  implementation tries to use high quality RNG if is
+  available (browser crypto object or nodejs crypto module).
+
+  If no high qualiry RNG, switches to the default Math based
+  RNG with proper waring in the console."
+  (:require [uuid.impl :as impl]))
+
+(defn v4
+  "Generate a v4 (random) UUID."
+  []
+  (uuid (impl/v4)))
+
+(def random
+  "Alias for `uuid.core/v4`."
+  v4)
diff --git a/vendor/uuid/impl.js b/vendor/uuid/impl.js
new file mode 100644
index 000000000..b79b2f4d3
--- /dev/null
+++ b/vendor/uuid/impl.js
@@ -0,0 +1,47 @@
+/*
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ *
+ * Copyright (c) 2016 Andrey Antukh <niwi@niwi.nz>
+*/
+"use strict";
+
+goog.provide("uuid.impl");
+goog.require("uuid.rng");
+
+goog.scope(function() {
+  const rng = uuid.rng;
+  const hexMap = [];
+
+  for (let i = 0; i < 256; i++) {
+    hexMap[i] = (i + 0x100).toString(16).substr(1);
+  }
+
+  function toHexString(buf) {
+    let i = 0;
+    return  (hexMap[buf[i++]] +
+             hexMap[buf[i++]] +
+             hexMap[buf[i++]] +
+             hexMap[buf[i++]] + '-' +
+             hexMap[buf[i++]] +
+             hexMap[buf[i++]] + '-' +
+             hexMap[buf[i++]] +
+             hexMap[buf[i++]] + '-' +
+             hexMap[buf[i++]] +
+             hexMap[buf[i++]] + '-' +
+             hexMap[buf[i++]] +
+             hexMap[buf[i++]] +
+             hexMap[buf[i++]] +
+             hexMap[buf[i++]] +
+             hexMap[buf[i++]] +
+             hexMap[buf[i++]]);
+  }
+
+  uuid.impl.v4 = function() {
+    const buf = rng.getBytes(16);
+    buf[6] = (buf[6] & 0x0f) | 0x40;
+    buf[8] = (buf[8] & 0x3f) | 0x80;
+    return cljs.core.uuid(toHexString(buf));
+  };
+})
diff --git a/vendor/uuid/rng.js b/vendor/uuid/rng.js
new file mode 100644
index 000000000..be1c73ac7
--- /dev/null
+++ b/vendor/uuid/rng.js
@@ -0,0 +1,44 @@
+/*
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ *
+ * Copyright (c) 2016 Andrey Antukh <niwi@niwi.nz>
+*/
+
+"use strict";
+
+goog.provide("uuid.rng");
+
+goog.scope(function() {
+  uuid.rng.getBytes = null;
+
+  // Check if nodejs rng is available (high quality);
+  if (goog.global.require !== undefined) {
+    const crypto = goog.global.require("crypto");
+
+    uuid.rng.getBytes = function(n) {
+      return crypto.randomBytes(n);
+    };
+  }
+  // Check if whatwg rng is available (high quality);
+  else if (goog.global.crypto.getRandomValues !== undefined) {
+    uuid.rng.getBytes = function(n) {
+      const buf = new Uint8Array(16);
+      goog.global.crypto.getRandomValues(buf);
+      return buf;
+    };
+  }
+  // Switch Back to the Math.random (low quality);
+  else {
+    console.warn("No high quality RNG available, switching back to Math.random.");
+    uuid.rng.getBytes = function(n) {
+      const buf = new Array(16);
+      for (let i = 0, r; i < 16; i++) {
+        if ((i & 0x03) === 0) { r = Math.random() * 0x100000000; }
+        buf[i] = r >>> ((i & 0x03) << 3) & 0xff;
+      }
+      return buf;
+    };
+  }
+});