From a087ebf512dafe626179070d4c77e3e69473e424 Mon Sep 17 00:00:00 2001
From: Simon Rettberg
Date: Sat, 10 Jun 2017 16:02:25 +0200
Subject: [inc/Util] Add randomUuid() function

---
 inc/util.inc.php | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

(limited to 'inc')

diff --git a/inc/util.inc.php b/inc/util.inc.php
index 5d1a4563..697ae3f9 100644
--- a/inc/util.inc.php
+++ b/inc/util.inc.php
@@ -434,4 +434,32 @@ SADFACE;
 		return $bytes;
 	}
 
+	/**
+	 * @return string a random UUID, v4.
+	 */
+	public static function randomUuid()
+	{
+		$b = unpack('h8a/h4b/h12c', self::randomBytes(12));
+		return sprintf('%08s-%04s-%04x-%04x-%012s',
+
+			// 32 bits for "time_low"
+			$b['a'],
+
+			// 16 bits for "time_mid"
+			$b['b'],
+
+			// 16 bits for "time_hi_and_version",
+			// four most significant bits holds version number 4
+			mt_rand(0, 0x0fff) | 0x4000,
+
+			// 16 bits, 8 bits for "clk_seq_hi_res",
+			// 8 bits for "clk_seq_low",
+			// two most significant bits holds zero and one for variant DCE1.1
+			mt_rand(0, 0x3fff) | 0x8000,
+
+			// 48 bits for "node"
+			$b['c']
+		);
+	}
+
 }
-- 
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