From 64807ba686860bbb9447d31bb0c7c7d705969939 Mon Sep 17 00:00:00 2001
From: Nikita Sinelnikov <nsinelnikov.work@gmail.com>
Date: Sat, 24 Nov 2018 17:56:47 +0200
Subject: [PATCH] added alternative random_bytes()

added alternative random_bytes() instead deprecated in PHP 7.2 mcrypt_create_iv()
---
 .../McryptPseudoRandomStringGenerator.php     | 27 ++++++++++++++-----
 1 file changed, 20 insertions(+), 7 deletions(-)

diff --git a/src/Facebook/PseudoRandomString/McryptPseudoRandomStringGenerator.php b/src/Facebook/PseudoRandomString/McryptPseudoRandomStringGenerator.php
index bf5737453..228af9843 100644
--- a/src/Facebook/PseudoRandomString/McryptPseudoRandomStringGenerator.php
+++ b/src/Facebook/PseudoRandomString/McryptPseudoRandomStringGenerator.php
@@ -39,11 +39,20 @@ class McryptPseudoRandomStringGenerator implements PseudoRandomStringGeneratorIn
      */
     public function __construct()
     {
-        if (!function_exists('mcrypt_create_iv')) {
-            throw new FacebookSDKException(
-                static::ERROR_MESSAGE .
-                'The function mcrypt_create_iv() does not exist.'
-            );
+        if (version_compare( PHP_VERSION, '7.1', '>=' )) {
+            if (!function_exists('random_bytes')) {
+                throw new FacebookSDKException(
+                    static::ERROR_MESSAGE .
+                    'The function random_bytes() does not exist.'
+                );
+            }   
+        } else {
+            if (!function_exists('mcrypt_create_iv')) {
+                throw new FacebookSDKException(
+                    static::ERROR_MESSAGE .
+                    'The function mcrypt_create_iv() does not exist.'
+                );
+            } 
         }
     }
 
@@ -54,12 +63,16 @@ public function getPseudoRandomString($length)
     {
         $this->validateLength($length);
 
-        $binaryString = mcrypt_create_iv($length, MCRYPT_DEV_URANDOM);
+        if (version_compare( PHP_VERSION, '7.1', '>=' )) {
+            $binaryString = random_bytes($length);
+        } else {
+            $binaryString = mcrypt_create_iv($length, MCRYPT_DEV_URANDOM);
+        }
 
         if ($binaryString === false) {
             throw new FacebookSDKException(
                 static::ERROR_MESSAGE .
-                'mcrypt_create_iv() returned an error.'
+                'mcrypt_create_iv() or random_bytes() returned an error.'
             );
         }