Drupal 8.0.0 beta 12. More info: https://www.drupal.org/node/2514176

core/lib/Drupal/Component/Uuid/Php.php

@@ -0,0 +1,50 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\Component\Uuid\Php.
+ */
+
+namespace Drupal\Component\Uuid;
+
+use Drupal\Component\Utility\Crypt;
+
+/**
+ * Generates a UUID v4 using PHP code.
+ *
+ * Loosely based on Ruby's UUIDTools generate_random logic.
+ *
+ * @see http://uuidtools.rubyforge.org/api/classes/UUIDTools/UUID.html
+ */
+class Php implements UuidInterface {
+
+  /**
+   * {@inheritdoc}
+   */
+  public function generate() {
+    $hex = substr(hash('sha256', Crypt::randomBytes(16)), 0, 32);
+
+    // The field names refer to RFC 4122 section 4.1.2.
+    $time_low = substr($hex, 0, 8);
+    $time_mid = substr($hex, 8, 4);
+
+    $time_hi_and_version = base_convert(substr($hex, 12, 4), 16, 10);
+    $time_hi_and_version &= 0x0FFF;
+    $time_hi_and_version |= (4 << 12);
+
+    $clock_seq_hi_and_reserved = base_convert(substr($hex, 16, 4), 16, 10);
+    $clock_seq_hi_and_reserved &= 0x3F;
+    $clock_seq_hi_and_reserved |= 0x80;
+
+    $clock_seq_low = substr($hex, 20, 2);
+    $nodes = substr($hex, 20);
+
+    $uuid = sprintf('%s-%s-%04x-%02x%02x-%s',
+      $time_low, $time_mid,
+      $time_hi_and_version, $clock_seq_hi_and_reserved,
+      $clock_seq_low, $nodes);
+
+    return $uuid;
+  }
+
+}