From 0e322469a646f7fcb9c9884370aec1b40e663bcf Mon Sep 17 00:00:00 2001
From: Dion Hulse <wordpress@dd32.id.au>
Date: Thu, 8 Oct 2015 00:02:24 +0000
Subject: [PATCH] Use PHP7's `random_int()` CSPRNG functionality in `wp_rand()`
 with a fallback to the `random_compat` library for PHP 5.x. `random_compat`
 offers a set of compatible functions for older versions of PHP, filling in
 the gap by using other PHP extensions when available. We still include our
 existing `wp_rand()` functionality as a fallback for when no proper CSPRNG
 exists on the system.

Props sarciszewski
See #28633

Built from https://develop.svn.wordpress.org/trunk@34922


git-svn-id: http://core.svn.wordpress.org/trunk@34887 1a063a9b-81f0-0310-95a4-ce76da25c4cd
---
 wp-includes/compat.php                        |   5 +
 wp-includes/pluggable.php                     |  33 +++-
 .../random_compat/byte_safe_strings.php       | 154 ++++++++++++++++
 wp-includes/random_compat/error_polyfill.php  |  56 ++++++
 wp-includes/random_compat/random.php          |  83 +++++++++
 .../random_compat/random_bytes_com_dotnet.php |  75 ++++++++
 .../random_bytes_dev_urandom.php              | 135 ++++++++++++++
 .../random_compat/random_bytes_mcrypt.php     |  70 +++++++
 .../random_compat/random_bytes_openssl.php    |  74 ++++++++
 wp-includes/random_compat/random_int.php      | 172 ++++++++++++++++++
 wp-includes/version.php                       |   2 +-
 11 files changed, 855 insertions(+), 4 deletions(-)
 create mode 100644 wp-includes/random_compat/byte_safe_strings.php
 create mode 100644 wp-includes/random_compat/error_polyfill.php
 create mode 100644 wp-includes/random_compat/random.php
 create mode 100644 wp-includes/random_compat/random_bytes_com_dotnet.php
 create mode 100644 wp-includes/random_compat/random_bytes_dev_urandom.php
 create mode 100644 wp-includes/random_compat/random_bytes_mcrypt.php
 create mode 100644 wp-includes/random_compat/random_bytes_openssl.php
 create mode 100644 wp-includes/random_compat/random_int.php

diff --git a/wp-includes/compat.php b/wp-includes/compat.php
index 781e7a728f..24da0adc3e 100644
--- a/wp-includes/compat.php
+++ b/wp-includes/compat.php
@@ -332,3 +332,8 @@ if ( ! interface_exists( 'JsonSerializable' ) ) {
 		public function jsonSerialize();
 	}
 }
+
+// random_int was introduced in PHP 7.0
+if ( ! function_exists( 'random_int' ) ) {
+	require ABSPATH . WPINC . '/random_compat/random.php';
+}
diff --git a/wp-includes/pluggable.php b/wp-includes/pluggable.php
index d58f18940b..36e330be3a 100644
--- a/wp-includes/pluggable.php
+++ b/wp-includes/pluggable.php
@@ -2132,9 +2132,11 @@ if ( !function_exists('wp_rand') ) :
  * Generates a random number
  *
  * @since 2.6.2
+ * @since 4.4 Uses PHP7 random_int() or the random_compat library if avaialble.
  *
  * @global string $rnd_value
  * @staticvar string $seed
+ * @staticvar bool $external_rand_source_available
  *
  * @param int $min Lower limit for the generated number
  * @param int $max Upper limit for the generated number
@@ -2143,6 +2145,34 @@ if ( !function_exists('wp_rand') ) :
 function wp_rand( $min = 0, $max = 0 ) {
 	global $rnd_value;
 
+	// Some misconfigured 32bit environments (Entropy PHP, for example) truncate integers larger than PHP_INT_MAX to PHP_INT_MAX rather than overflowing them to floats.
+	$max_random_number = 3000000000 === 2147483647 ? (float) "4294967295" : 4294967295; // 4294967295 = 0xffffffff
+
+	// We only handle Ints, floats are truncated to their integer value.
+	$min = (int) $min;
+	$max = (int) $max;
+
+	// Use PHP's CSPRNG, or a compatible method
+	static $use_random_int_functionality = true;
+	if ( $use_random_int_functionality ) {
+		try {
+			$_max = ( 0 != $max ) ? $max : $max_random_number;
+			// wp_rand() can accept arguements in either order, PHP cannot.
+			$_max = max( $min, $_max );
+			$_min = min( $min, $_max );
+			$val = random_int( $_min, $_max );
+			if ( false !== $val ) {
+				return absint( $val );
+			} else {
+				$use_random_int_functionality = false;
+			}
+		} catch ( Throwable $t ) { 
+			$use_random_int_functionality = false;
+		} catch ( Exception $e ) {
+			$use_random_int_functionality = false;
+		}
+	}
+
 	// Reset $rnd_value after 14 uses
 	// 32(md5) + 40(sha1) + 40(sha1) / 8 = 14 random numbers from $rnd_value
 	if ( strlen($rnd_value) < 8 ) {
@@ -2167,9 +2197,6 @@ function wp_rand( $min = 0, $max = 0 ) {
 
 	$value = abs(hexdec($value));
 
-	// Some misconfigured 32bit environments (Entropy PHP, for example) truncate integers larger than PHP_INT_MAX to PHP_INT_MAX rather than overflowing them to floats.
-	$max_random_number = 3000000000 === 2147483647 ? (float) "4294967295" : 4294967295; // 4294967295 = 0xffffffff
-
 	// Reduce the value to be within the min - max range
 	if ( $max != 0 )
 		$value = $min + ( $max - $min + 1 ) * $value / ( $max_random_number + 1 );
diff --git a/wp-includes/random_compat/byte_safe_strings.php b/wp-includes/random_compat/byte_safe_strings.php
new file mode 100644
index 0000000000..c6dc2a865a
--- /dev/null
+++ b/wp-includes/random_compat/byte_safe_strings.php
@@ -0,0 +1,154 @@
+<?php
+/**
+ * Random_* Compatibility Library
+ * for using the new PHP 7 random_* API in PHP 5 projects
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2015 Paragon Initiative Enterprises
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+if (!function_exists('RandomCompat_strlen')) {
+    if (defined('MB_OVERLOAD_STRING') && ini_get('mbstring.func_overload') & MB_OVERLOAD_STRING) {
+        /**
+         * strlen() implementation that isn't brittle to mbstring.func_overload
+         *
+         * This version uses mb_strlen() in '8bit' mode to treat strings as raw
+         * binary rather than UTF-8, ISO-8859-1, etc
+         *
+         * @param string $binary_string
+         *
+         * @throws TypeError
+         *
+         * @return int
+         */
+        function RandomCompat_strlen($binary_string)
+        {
+            if (!is_string($binary_string)) {
+                throw new TypeError(
+                    'RandomCompat_strlen() expects a string'
+                );
+            }
+            return mb_strlen($binary_string, '8bit');
+        }
+    } else {
+        /**
+         * strlen() implementation that isn't brittle to mbstring.func_overload
+         *
+         * This version just used the default strlen()
+         *
+         * @param string $binary_string
+         *
+         * @throws TypeError
+         *
+         * @return int
+         */
+        function RandomCompat_strlen($binary_string)
+        {
+            if (!is_string($binary_string)) {
+                throw new TypeError(
+                    'RandomCompat_strlen() expects a string'
+                );
+            }
+            return strlen($binary_string);
+        }
+    }
+}
+
+if (!function_exists('RandomCompat_substr')) {
+    if (defined('MB_OVERLOAD_STRING') && ini_get('mbstring.func_overload') & MB_OVERLOAD_STRING) {
+        /**
+         * substr() implementation that isn't brittle to mbstring.func_overload
+         *
+         * This version uses mb_substr() in '8bit' mode to treat strings as raw
+         * binary rather than UTF-8, ISO-8859-1, etc
+         *
+         * @param string $binary_string
+         * @param int $start
+         * @param int $length (optional)
+         *
+         * @throws TypeError
+         *
+         * @return string
+         */
+        function RandomCompat_substr($binary_string, $start, $length = null)
+        {
+            if (!is_string($binary_string)) {
+                throw new TypeError(
+                    'RandomCompat_substr(): First argument should be a string'
+                );
+            }
+            if (!is_int($start)) {
+                throw new TypeError(
+                    'RandomCompat_substr(): Second argument should be an integer'
+                );
+            }
+            if ($length === null) {
+                /**
+                 * mb_substr($str, 0, NULL, '8bit') returns an empty string on
+                 * PHP 5.3, so we have to find the length ourselves.
+                 */
+                $length = RandomCompat_strlen($length) - $start;
+            } elseif (!is_int($length)) {
+                throw new TypeError(
+                    'RandomCompat_substr(): Third argument should be an integer, or omitted'
+                );
+            }
+            return mb_substr($binary_string, $start, $length, '8bit');
+        }
+    } else {
+        /**
+         * substr() implementation that isn't brittle to mbstring.func_overload
+         *
+         * This version just uses the default substr()
+         *
+         * @param string $binary_string
+         * @param int $start
+         * @param int $length (optional)
+         *
+         * @throws TypeError
+         *
+         * @return string
+         */
+        function RandomCompat_substr($binary_string, $start, $length = null)
+        {
+            if (!is_string($binary_string)) {
+                throw new TypeError(
+                    'RandomCompat_substr(): First argument should be a string'
+                );
+            }
+            if (!is_int($start)) {
+                throw new TypeError(
+                    'RandomCompat_substr(): Second argument should be an integer'
+                );
+            }
+            if ($length !== null) {
+                if (!is_int($length)) {
+                    throw new TypeError(
+                        'RandomCompat_substr(): Third argument should be an integer, or omitted'
+                    );
+                }
+                return substr($binary_string, $start, $length);
+            }
+            return substr($binary_string, $start);
+        }
+    }
+}
diff --git a/wp-includes/random_compat/error_polyfill.php b/wp-includes/random_compat/error_polyfill.php
new file mode 100644
index 0000000000..7253ff7245
--- /dev/null
+++ b/wp-includes/random_compat/error_polyfill.php
@@ -0,0 +1,56 @@
+<?php
+/**
+ * Random_* Compatibility Library 
+ * for using the new PHP 7 random_* API in PHP 5 projects
+ * 
+ * The MIT License (MIT)
+ * 
+ * Copyright (c) 2015 Paragon Initiative Enterprises
+ * 
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ * 
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+if (!interface_exists('Throwable', false)) {
+    interface Throwable
+    {
+        public function getMessage();
+        public function getCode();
+        public function getFile();
+        public function getLine();
+        public function getTrace();
+        public function getTraceAsString();
+        public function getPrevious();
+        public function __toString();
+    }
+}
+
+if (!class_exists('Error', false)) {
+    // We can't really avoid making this extend Exception in PHP 5.
+    class Error extends Exception implements Throwable
+    {
+        
+    }
+}
+
+if (!class_exists('TypeError', false)) {
+    class TypeError extends Error
+    {
+        
+    }
+}
\ No newline at end of file
diff --git a/wp-includes/random_compat/random.php b/wp-includes/random_compat/random.php
new file mode 100644
index 0000000000..1530f7ee25
--- /dev/null
+++ b/wp-includes/random_compat/random.php
@@ -0,0 +1,83 @@
+<?php
+/**
+ * Random_* Compatibility Library 
+ * for using the new PHP 7 random_* API in PHP 5 projects
+ * 
+ * The MIT License (MIT)
+ * 
+ * Copyright (c) 2015 Paragon Initiative Enterprises
+ * 
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ * 
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+if (!defined('PHP_VERSION_ID')) {
+    // This constant was introduced in PHP 5.2.7
+    $version = explode('.', PHP_VERSION);
+    define('PHP_VERSION_ID', ($version[0] * 10000 + $version[1] * 100 + $version[2]));
+}
+if (PHP_VERSION_ID < 70000) {
+    if (!defined('RANDOM_COMPAT_READ_BUFFER')) {
+        define('RANDOM_COMPAT_READ_BUFFER', 8);
+    }
+    require_once "byte_safe_strings.php";
+    require_once "error_polyfill.php";
+    if (!function_exists('random_bytes')) {
+        /**
+         * PHP 5.2.0 - 5.6.x way to implement random_bytes()
+         * 
+         * We use conditional statements here to define the function in accordance
+         * to the operating environment. It's a micro-optimization.
+         * 
+         * In order of preference:
+         *   1. fread() /dev/urandom if available
+         *   2. mcrypt_create_iv($bytes, MCRYPT_CREATE_IV)
+         *   3. COM('CAPICOM.Utilities.1')->GetRandom()
+         *   4. openssl_random_pseudo_bytes()
+         * 
+         * See ERRATA.md for our reasoning behind this particular order
+         */
+        if (!ini_get('open_basedir') && is_readable('/dev/urandom')) {
+            // See random_bytes_dev_urandom.php
+            require_once "random_bytes_dev_urandom.php";
+        } elseif (PHP_VERSION_ID >= 50307 && function_exists('mcrypt_create_iv')) {
+            // See random_bytes_mcrypt.php
+            require_once "random_bytes_mcrypt.php";
+        } elseif (extension_loaded('com_dotnet')) {
+            // See random_bytes_com_dotnet.php
+            require_once "random_bytes_com_dotnet.php";
+        } elseif (function_exists('openssl_random_pseudo_bytes')) {
+            // See random_bytes_openssl.php
+            require_once "random_bytes_openssl.php";
+        } else {
+            /**
+             * We don't have any more options, so let's throw an exception right now
+             * and hope the developer won't let it fail silently.
+             */
+            function random_bytes()
+            {
+                throw new Exception(
+                    'There is no suitable CSPRNG installed on your system'
+                );
+            }
+        }
+    }
+    if (!function_exists('random_int')) {
+        require_once "random_int.php";
+    }
+}
diff --git a/wp-includes/random_compat/random_bytes_com_dotnet.php b/wp-includes/random_compat/random_bytes_com_dotnet.php
new file mode 100644
index 0000000000..cebe616ab2
--- /dev/null
+++ b/wp-includes/random_compat/random_bytes_com_dotnet.php
@@ -0,0 +1,75 @@
+<?php
+/**
+ * Random_* Compatibility Library 
+ * for using the new PHP 7 random_* API in PHP 5 projects
+ * 
+ * The MIT License (MIT)
+ * 
+ * Copyright (c) 2015 Paragon Initiative Enterprises
+ * 
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ * 
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+/**
+ * Windows with PHP < 5.3.0 will not have the function
+ * openssl_random_pseudo_bytes() available, so let's use
+ * CAPICOM to work around this deficiency.
+ * 
+ * @param int $bytes
+ * 
+ * @throws Exception
+ * 
+ * @return string
+ */
+function random_bytes($bytes)
+{
+    if (!is_int($bytes)) {
+        throw new TypeError(
+            'Length must be an integer'
+        );
+    }
+    if ($bytes < 1) {
+        throw new Error(
+            'Length must be greater than 0'
+        );
+    }
+    $buf = '';
+    $util = new COM('CAPICOM.Utilities.1');
+    $execCount = 0;
+    /**
+     * Let's not let it loop forever. If we run N times and fail to
+     * get N bytes of random data, then CAPICOM has failed us.
+     */
+    do {
+        $buf .= base64_decode($util->GetRandom($bytes, 0));
+        if (RandomCompat_strlen($buf) >= $bytes) {
+            /**
+             * Return our random entropy buffer here:
+             */
+            return RandomCompat_substr($buf, 0, $bytes);
+        }
+        ++$execCount; 
+    } while ($execCount < $bytes);
+    /**
+     * If we reach here, PHP has failed us.
+     */
+    throw new Exception(
+        'PHP failed to generate random data.'
+    );
+}
diff --git a/wp-includes/random_compat/random_bytes_dev_urandom.php b/wp-includes/random_compat/random_bytes_dev_urandom.php
new file mode 100644
index 0000000000..09bd49f551
--- /dev/null
+++ b/wp-includes/random_compat/random_bytes_dev_urandom.php
@@ -0,0 +1,135 @@
+<?php
+/**
+ * Random_* Compatibility Library 
+ * for using the new PHP 7 random_* API in PHP 5 projects
+ * 
+ * The MIT License (MIT)
+ * 
+ * Copyright (c) 2015 Paragon Initiative Enterprises
+ * 
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ * 
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+if (!defined('RANDOM_COMPAT_READ_BUFFER')) {
+    define('RANDOM_COMPAT_READ_BUFFER', 8);
+}
+
+/**
+ * Unless open_basedir is enabled, use /dev/urandom for
+ * random numbers in accordance with best practices
+ * 
+ * Why we use /dev/urandom and not /dev/random
+ * @ref http://sockpuppet.org/blog/2014/02/25/safely-generate-random-numbers
+ * 
+ * @param int $bytes
+ * 
+ * @throws Exception
+ * 
+ * @return string
+ */
+function random_bytes($bytes)
+{
+    static $fp = null;
+    /**
+     * This block should only be run once
+     */
+    if (empty($fp)) {
+        /**
+         * We use /dev/urandom if it is a char device.
+         * We never fall back to /dev/random
+         */
+        $fp = fopen('/dev/urandom', 'rb');
+        if (!empty($fp)) {
+            $st = fstat($fp);
+            if (($st['mode'] & 0170000) !== 020000) {
+                fclose($fp);
+                $fp = false;
+            }
+        }
+        /**
+         * stream_set_read_buffer() does not exist in HHVM
+         * 
+         * If we don't set the stream's read buffer to 0, PHP will
+         * internally buffer 8192 bytes, which can waste entropy
+         * 
+         * stream_set_read_buffer returns 0 on success
+         */
+        if (!empty($fp) && function_exists('stream_set_read_buffer')) {
+            stream_set_read_buffer($fp, RANDOM_COMPAT_READ_BUFFER);
+        }
+    }
+    if (!is_int($bytes)) {
+        throw new TypeError(
+            'Length must be an integer'
+        );
+    }
+    if ($bytes < 1) {
+        throw new Error(
+            'Length must be greater than 0'
+        );
+    }
+    /**
+     * This if() block only runs if we managed to open a file handle
+     * 
+     * It does not belong in an else {} block, because the above 
+     * if (empty($fp)) line is logic that should only be run once per
+     * page load.
+     */
+    if (!empty($fp)) {
+        $remaining = $bytes;
+        $buf = '';
+        /**
+         * We use fread() in a loop to protect against partial reads
+         */
+        do {
+            $read = fread($fp, $remaining); 
+            if ($read === false) {
+                /**
+                 * We cannot safely read from the file. Exit the
+                 * do-while loop and trigger the exception condition
+                 */
+                $buf = false;
+                break;
+            }
+            /**
+             * Decrease the number of bytes returned from remaining
+             */
+            $remaining -= RandomCompat_strlen($read);
+            $buf .= $read;
+        } while ($remaining > 0);
+        
+        /**
+         * Is our result valid?
+         */
+        if ($buf !== false) {
+            if (RandomCompat_strlen($buf) === $bytes) {
+                /**
+                 * Return our random entropy buffer here:
+                 */
+                return $buf;
+            }
+        }
+    }
+    /**
+     * If we reach here, PHP has failed us.
+     */
+    throw new Exception(
+        'PHP failed to generate random data.'
+    );
+}
diff --git a/wp-includes/random_compat/random_bytes_mcrypt.php b/wp-includes/random_compat/random_bytes_mcrypt.php
new file mode 100644
index 0000000000..8d3b728371
--- /dev/null
+++ b/wp-includes/random_compat/random_bytes_mcrypt.php
@@ -0,0 +1,70 @@
+<?php
+/**
+ * Random_* Compatibility Library 
+ * for using the new PHP 7 random_* API in PHP 5 projects
+ * 
+ * The MIT License (MIT)
+ * 
+ * Copyright (c) 2015 Paragon Initiative Enterprises
+ * 
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ * 
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+
+/**
+ * Powered by ext/mcrypt (and thankfully NOT libmcrypt)
+ * 
+ * @ref https://bugs.php.net/bug.php?id=55169
+ * @ref https://github.com/php/php-src/blob/c568ffe5171d942161fc8dda066bce844bdef676/ext/mcrypt/mcrypt.c#L1321-L1386
+ * 
+ * @param int $bytes
+ * 
+ * @throws Exception
+ * 
+ * @return string
+ */
+function random_bytes($bytes)
+{
+    if (!is_int($bytes)) {
+        throw new TypeError(
+            'Length must be an integer'
+        );
+    }
+    if ($bytes < 1) {
+        throw new Error(
+            'Length must be greater than 0'
+        );
+    }
+
+    $buf = mcrypt_create_iv($bytes, MCRYPT_DEV_URANDOM);
+    if ($buf !== false) {
+        if (RandomCompat_strlen($buf) === $bytes) {
+            /**
+             * Return our random entropy buffer here:
+             */
+            return $buf;
+        }
+    }
+    /**
+     * If we reach here, PHP has failed us.
+     */
+    throw new Exception(
+        'PHP failed to generate random data.'
+    );
+}
diff --git a/wp-includes/random_compat/random_bytes_openssl.php b/wp-includes/random_compat/random_bytes_openssl.php
new file mode 100644
index 0000000000..075fd8d89b
--- /dev/null
+++ b/wp-includes/random_compat/random_bytes_openssl.php
@@ -0,0 +1,74 @@
+<?php
+/**
+ * Random_* Compatibility Library 
+ * for using the new PHP 7 random_* API in PHP 5 projects
+ * 
+ * The MIT License (MIT)
+ * 
+ * Copyright (c) 2015 Paragon Initiative Enterprises
+ * 
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ * 
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+/**
+ * Since openssl_random_pseudo_bytes() uses openssl's 
+ * RAND_pseudo_bytes() API, which has been marked as deprecated by the
+ * OpenSSL team, this is our last resort before failure.
+ * 
+ * @ref https://www.openssl.org/docs/crypto/RAND_bytes.html
+ * 
+ * @param int $bytes
+ * 
+ * @throws Exception
+ * 
+ * @return string
+ */
+function random_bytes($bytes)
+{
+    if (!is_int($bytes)) {
+        throw new TypeError(
+            'Length must be an integer'
+        );
+    }
+    if ($bytes < 1) {
+        throw new Error(
+            'Length must be greater than 0'
+        );
+    }
+    $secure = true;
+    /**
+     * $secure is passed by reference. If it's set to false, fail. Note
+     * that this will only return false if this function fails to return
+     * any data.
+     * 
+     * @ref https://github.com/paragonie/random_compat/issues/6#issuecomment-119564973
+     */
+    $buf = openssl_random_pseudo_bytes($bytes, $secure);
+    if ($buf !== false && $secure) {
+        if (RandomCompat_strlen($buf) === $bytes) {
+            return $buf;
+        }
+    }
+    /**
+     * If we reach here, PHP has failed us.
+     */
+    throw new Exception(
+        'PHP failed to generate random data.'
+    );
+}
diff --git a/wp-includes/random_compat/random_int.php b/wp-includes/random_compat/random_int.php
new file mode 100644
index 0000000000..7fd50e7efd
--- /dev/null
+++ b/wp-includes/random_compat/random_int.php
@@ -0,0 +1,172 @@
+<?php
+/**
+ * Random_* Compatibility Library 
+ * for using the new PHP 7 random_* API in PHP 5 projects
+ * 
+ * The MIT License (MIT)
+ * 
+ * Copyright (c) 2015 Paragon Initiative Enterprises
+ * 
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ * 
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+/**
+ * Fetch a random integer between $min and $max inclusive
+ * 
+ * @param int $min
+ * @param int $max
+ * 
+ * @throws Exception
+ * 
+ * @return int
+ */
+function random_int($min, $max)
+{
+    /**
+     * Type and input logic checks
+     */
+    if (!is_numeric($min)) {
+        throw new TypeError(
+            'random_int(): $min must be an integer'
+        );
+    }
+    if (!is_numeric($max)) {
+        throw new TypeError(
+            'random_int(): $max must be an integer'
+        );
+    }
+
+    $min = (int) $min;
+    $max = (int) $max;
+
+    if ($min > $max) {
+        throw new Error(
+            'Minimum value must be less than or equal to the maximum value'
+        );
+    }
+    if ($max === $min) {
+        return $min;
+    }
+
+    /**
+     * Initialize variables to 0
+     * 
+     * We want to store:
+     * $bytes => the number of random bytes we need
+     * $mask => an integer bitmask (for use with the &) operator
+     *          so we can minimize the number of discards
+     */
+    $attempts = $bits = $bytes = $mask = $valueShift = 0;
+
+    /**
+     * At this point, $range is a positive number greater than 0. It might
+     * overflow, however, if $max - $min > PHP_INT_MAX. PHP will cast it to
+     * a float and we will lose some precision.
+     */
+    $range = $max - $min;
+
+    /**
+     * Test for integer overflow:
+     */
+    if (!is_int($range)) {
+        /**
+         * Still safely calculate wider ranges.
+         * Provided by @CodesInChaos, @oittaa
+         * 
+         * @ref https://gist.github.com/CodesInChaos/03f9ea0b58e8b2b8d435
+         * 
+         * We use ~0 as a mask in this case because it generates all 1s
+         * 
+         * @ref https://eval.in/400356 (32-bit)
+         * @ref http://3v4l.org/XX9r5  (64-bit)
+         */
+        $bytes = PHP_INT_SIZE;
+        $mask = ~0;
+    } else {
+        /**
+         * $bits is effectively ceil(log($range, 2)) without dealing with 
+         * type juggling
+         */
+        while ($range > 0) {
+            if ($bits % 8 === 0) {
+               ++$bytes;
+            }
+            ++$bits;
+            $range >>= 1;
+            $mask = $mask << 1 | 1;
+        }
+        $valueShift = $min;
+    }
+
+    /**
+     * Now that we have our parameters set up, let's begin generating
+     * random integers until one falls between $min and $max
+     */
+    do {
+        /**
+         * The rejection probability is at most 0.5, so this corresponds
+         * to a failure probability of 2^-128 for a working RNG
+         */
+        if ($attempts > 128) {
+            throw new Exception(
+                'random_int: RNG is broken - too many rejections'
+            );
+        }
+
+        /**
+         * Let's grab the necessary number of random bytes
+         */
+        $randomByteString = random_bytes($bytes);
+        if ($randomByteString === false) {
+            throw new Exception(
+                'Random number generator failure'
+            );
+        }
+
+        /**
+         * Let's turn $randomByteString into an integer
+         * 
+         * This uses bitwise operators (<< and |) to build an integer
+         * out of the values extracted from ord()
+         * 
+         * Example: [9F] | [6D] | [32] | [0C] =>
+         *   159 + 27904 + 3276800 + 201326592 =>
+         *   204631455
+         */
+        $val = 0;
+        for ($i = 0; $i < $bytes; ++$i) {
+            $val |= ord($randomByteString[$i]) << ($i * 8);
+        }
+
+        /**
+         * Apply mask
+         */
+        $val &= $mask;
+        $val += $valueShift;
+
+        ++$attempts;
+        /**
+         * If $val overflows to a floating point number,
+         * ... or is larger than $max,
+         * ... or smaller than $int,
+         * then try again.
+         */
+    } while (!is_int($val) || $val > $max || $val < $min);
+    return (int) $val;
+}
diff --git a/wp-includes/version.php b/wp-includes/version.php
index 2c2d209929..66d6ccc671 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.4-alpha-34921';
+$wp_version = '4.4-alpha-34922';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.