diff --git a/wp-includes/pluggable.php b/wp-includes/pluggable.php
index 6a19509c55..0bbd91b6b7 100644
--- a/wp-includes/pluggable.php
+++ b/wp-includes/pluggable.php
@@ -2188,7 +2188,7 @@ function wp_rand( $min = 0, $max = 0 ) {
 			} else {
 				$use_random_int_functionality = false;
 			}
-		} catch ( Throwable $t ) {
+		} catch ( Error $e ) {
 			$use_random_int_functionality = false;
 		} catch ( Exception $e ) {
 			$use_random_int_functionality = false;
diff --git a/wp-includes/random_compat/byte_safe_strings.php b/wp-includes/random_compat/byte_safe_strings.php
index c6dc2a865a..a3cc90b146 100644
--- a/wp-includes/random_compat/byte_safe_strings.php
+++ b/wp-includes/random_compat/byte_safe_strings.php
@@ -27,7 +27,10 @@
  */
 
 if (!function_exists('RandomCompat_strlen')) {
-    if (defined('MB_OVERLOAD_STRING') && ini_get('mbstring.func_overload') & MB_OVERLOAD_STRING) {
+    if (
+        defined('MB_OVERLOAD_STRING') &&
+        ini_get('mbstring.func_overload') & MB_OVERLOAD_STRING
+    ) {
         /**
          * strlen() implementation that isn't brittle to mbstring.func_overload
          *
@@ -74,7 +77,10 @@ if (!function_exists('RandomCompat_strlen')) {
 }
 
 if (!function_exists('RandomCompat_substr')) {
-    if (defined('MB_OVERLOAD_STRING') && ini_get('mbstring.func_overload') & MB_OVERLOAD_STRING) {
+    if (
+        defined('MB_OVERLOAD_STRING') &&
+        ini_get('mbstring.func_overload') & MB_OVERLOAD_STRING
+    ) {
         /**
          * substr() implementation that isn't brittle to mbstring.func_overload
          *
diff --git a/wp-includes/random_compat/cast_to_int.php b/wp-includes/random_compat/cast_to_int.php
new file mode 100644
index 0000000000..474ce64008
--- /dev/null
+++ b/wp-includes/random_compat/cast_to_int.php
@@ -0,0 +1,64 @@
+<?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_intval')) {
+    
+    /**
+     * Cast to an integer if we can, safely.
+     * 
+     * If you pass it a float in the range (~PHP_INT_MAX, PHP_INT_MAX)
+     * (non-inclusive), it will sanely cast it to an int. If you it's equal to
+     * ~PHP_INT_MAX or PHP_INT_MAX, we let it fail as not an integer. Floats 
+     * lose precision, so the <= and => operators might accidentally let a float
+     * through.
+     * 
+     * @param numeric $number The number we want to convert to an int
+     * @param boolean $fail_open Set to true to not throw an exception
+     * 
+     * @return int (or float if $fail_open)
+     */
+    function RandomCompat_intval($number, $fail_open = false)
+    {
+        if (is_numeric($number)) {
+            $number += 0;
+        }
+        if (
+            is_float($number) &&
+            $number > ~PHP_INT_MAX &&
+            $number < PHP_INT_MAX
+        ) {
+            $number = (int) $number;
+        }
+        if (is_int($number) || $fail_open) {
+            return $number;
+        }
+        throw new TypeError(
+            'Expected an integer.'
+        );
+    }
+}
diff --git a/wp-includes/random_compat/error_polyfill.php b/wp-includes/random_compat/error_polyfill.php
index 9c73649289..57cfefdcd1 100644
--- a/wp-includes/random_compat/error_polyfill.php
+++ b/wp-includes/random_compat/error_polyfill.php
@@ -26,15 +26,9 @@
  * SOFTWARE.
  */
 
-if (!interface_exists('Throwable', false)) {
-    interface Throwable
-    {
-    }
-}
-
 if (!class_exists('Error', false)) {
     // We can't really avoid making this extend Exception in PHP 5.
-    class Error extends Exception implements Throwable
+    class Error extends Exception
     {
         
     }
diff --git a/wp-includes/random_compat/random.php b/wp-includes/random_compat/random.php
index 1530f7ee25..1a4b326ed4 100644
--- a/wp-includes/random_compat/random.php
+++ b/wp-includes/random_compat/random.php
@@ -28,15 +28,18 @@
 
 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]));
+    $RandomCompatversion = explode('.', PHP_VERSION);
+    define('PHP_VERSION_ID', ($RandomCompatversion[0] * 10000 + $RandomCompatversion[1] * 100 + $RandomCompatversion[2]));
+    unset($RandomCompatversion);
 }
 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";
+    $__DIR__ = dirname(__FILE__);
+    require_once $__DIR__.'/byte_safe_strings.php';
+    require_once $__DIR__.'/cast_to_int.php';
+    require_once $__DIR__.'/error_polyfill.php';
     if (!function_exists('random_bytes')) {
         /**
          * PHP 5.2.0 - 5.6.x way to implement random_bytes()
@@ -45,26 +48,68 @@ if (PHP_VERSION_ID < 70000) {
          * to the operating environment. It's a micro-optimization.
          * 
          * In order of preference:
-         *   1. fread() /dev/urandom if available
-         *   2. mcrypt_create_iv($bytes, MCRYPT_CREATE_IV)
-         *   3. COM('CAPICOM.Utilities.1')->GetRandom()
-         *   4. openssl_random_pseudo_bytes()
+         *   1. Use libsodium if available.
+         *   2. fread() /dev/urandom if available (never on Windows)
+         *   3. mcrypt_create_iv($bytes, MCRYPT_CREATE_IV)
+         *   4. COM('CAPICOM.Utilities.1')->GetRandom()
+         *   5. openssl_random_pseudo_bytes() (absolute last resort)
          * 
          * See ERRATA.md for our reasoning behind this particular order
          */
-        if (!ini_get('open_basedir') && is_readable('/dev/urandom')) {
+        if (extension_loaded('libsodium')) {
+            // See random_bytes_libsodium.php
+            require_once $__DIR__.'/random_bytes_libsodium.php';
+        }
+        if (
+            !function_exists('random_bytes') && 
+            DIRECTORY_SEPARATOR === '/' &&
+            @is_readable('/dev/urandom')
+        ) {
+            // DIRECTORY_SEPARATOR === '/' on Unix-like OSes -- this is a fast
+            // way to exclude Windows.
+            // 
+            // Error suppression on is_readable() in case of an open_basedir or 
+            // safe_mode failure. All we care about is whether or not we can 
+            // read it at this point. If the PHP environment is going to panic 
+            // over trying to see if the file can be read in the first place,
+            // that is not helpful to us here.
+            
             // See random_bytes_dev_urandom.php
-            require_once "random_bytes_dev_urandom.php";
-        } elseif (PHP_VERSION_ID >= 50307 && function_exists('mcrypt_create_iv')) {
+            require_once $__DIR__.'/random_bytes_dev_urandom.php';
+        }
+        if (
+            !function_exists('random_bytes') &&
+            PHP_VERSION_ID >= 50307 &&
+            extension_loaded('mcrypt')
+        ) {
             // 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')) {
+            require_once $__DIR__.'/random_bytes_mcrypt.php';
+        }
+        if (
+            !function_exists('random_bytes') && 
+            extension_loaded('com_dotnet') &&
+            class_exists('COM')
+        ) {
+            try {
+                $RandomCompatCOMtest = new COM('CAPICOM.Utilities.1');
+                if (method_exists($RandomCompatCOMtest, 'GetRandom')) {
+                    // See random_bytes_com_dotnet.php
+                    require_once $__DIR__.'/random_bytes_com_dotnet.php';
+                }
+            } catch (com_exception $e) {
+                // Don't try to use it.
+            }
+            unset($RandomCompatCOMtest);
+        }
+        if (
+            !function_exists('random_bytes') && 
+            extension_loaded('openssl') &&
+            PHP_VERSION_ID >= 50300
+        ) {
             // See random_bytes_openssl.php
-            require_once "random_bytes_openssl.php";
-        } else {
+            require_once $__DIR__.'/random_bytes_openssl.php';
+        }
+        if (!function_exists('random_bytes')) {
             /**
              * 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.
@@ -78,6 +123,7 @@ if (PHP_VERSION_ID < 70000) {
         }
     }
     if (!function_exists('random_int')) {
-        require_once "random_int.php";
+        require_once $__DIR__.'/random_int.php';
     }
+    unset($__DIR__);
 }
diff --git a/wp-includes/random_compat/random_bytes_com_dotnet.php b/wp-includes/random_compat/random_bytes_com_dotnet.php
index cebe616ab2..c0ae639a8d 100644
--- a/wp-includes/random_compat/random_bytes_com_dotnet.php
+++ b/wp-includes/random_compat/random_bytes_com_dotnet.php
@@ -39,9 +39,11 @@
  */
 function random_bytes($bytes)
 {
-    if (!is_int($bytes)) {
+    try {
+        $bytes = RandomCompat_intval($bytes);
+    } catch (TypeError $ex) {
         throw new TypeError(
-            'Length must be an integer'
+            'random_bytes(): $bytes must be an integer'
         );
     }
     if ($bytes < 1) {
diff --git a/wp-includes/random_compat/random_bytes_dev_urandom.php b/wp-includes/random_compat/random_bytes_dev_urandom.php
index 09bd49f551..5606dbbec9 100644
--- a/wp-includes/random_compat/random_bytes_dev_urandom.php
+++ b/wp-includes/random_compat/random_bytes_dev_urandom.php
@@ -74,9 +74,11 @@ function random_bytes($bytes)
             stream_set_read_buffer($fp, RANDOM_COMPAT_READ_BUFFER);
         }
     }
-    if (!is_int($bytes)) {
+    try {
+        $bytes = RandomCompat_intval($bytes);
+    } catch (TypeError $ex) {
         throw new TypeError(
-            'Length must be an integer'
+            'random_bytes(): $bytes must be an integer'
         );
     }
     if ($bytes < 1) {
diff --git a/wp-includes/random_compat/random_bytes_libsodium.php b/wp-includes/random_compat/random_bytes_libsodium.php
new file mode 100644
index 0000000000..796ba6a626
--- /dev/null
+++ b/wp-includes/random_compat/random_bytes_libsodium.php
@@ -0,0 +1,84 @@
+<?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 the libsodium PHP extension is loaded, we'll use it above any other
+ * solution.
+ *
+ * libsodium-php project:
+ * @ref https://github.com/jedisct1/libsodium-php
+ *
+ * @param int $bytes
+ *
+ * @throws Exception
+ *
+ * @return string
+ */
+function random_bytes($bytes)
+{
+    try {
+        $bytes = RandomCompat_intval($bytes);
+    } catch (TypeError $ex) {
+        throw new TypeError(
+            'random_bytes(): $bytes must be an integer'
+        );
+    }
+    if ($bytes < 1) {
+        throw new Error(
+            'Length must be greater than 0'
+        );
+    }
+    /**
+     * \Sodium\randombytes_buf() doesn't allow more than 2147483647 bytes to be
+     * generated in one invocation.
+     */
+    if ($bytes > 2147483647) {
+        $buf = '';
+        for ($i = 0; $i < $bytes; $i += 1073741824) {
+            $n = ($bytes - $i) > 1073741824
+                ? 1073741824
+                : $bytes - $i;
+            $buf .= \Sodium\randombytes_buf($n);
+        }
+    } else {
+        $buf = \Sodium\randombytes_buf($bytes);
+    }
+
+    if ($buf !== false) {
+        if (RandomCompat_strlen($buf) === $bytes) {
+            return $buf;
+        }
+    }
+
+    /**
+     * If we reach here, PHP has failed us.
+     */
+    throw new Exception(
+        'PHP failed to generate random data.'
+    );
+}
diff --git a/wp-includes/random_compat/random_bytes_mcrypt.php b/wp-includes/random_compat/random_bytes_mcrypt.php
index 8d3b728371..8524c52245 100644
--- a/wp-includes/random_compat/random_bytes_mcrypt.php
+++ b/wp-includes/random_compat/random_bytes_mcrypt.php
@@ -41,9 +41,11 @@
  */
 function random_bytes($bytes)
 {
-    if (!is_int($bytes)) {
+    try {
+        $bytes = RandomCompat_intval($bytes);
+    } catch (TypeError $ex) {
         throw new TypeError(
-            'Length must be an integer'
+            'random_bytes(): $bytes must be an integer'
         );
     }
     if ($bytes < 1) {
@@ -52,7 +54,7 @@ function random_bytes($bytes)
         );
     }
 
-    $buf = mcrypt_create_iv($bytes, MCRYPT_DEV_URANDOM);
+    $buf = @mcrypt_create_iv($bytes, MCRYPT_DEV_URANDOM);
     if ($buf !== false) {
         if (RandomCompat_strlen($buf) === $bytes) {
             /**
diff --git a/wp-includes/random_compat/random_bytes_openssl.php b/wp-includes/random_compat/random_bytes_openssl.php
index 075fd8d89b..db05e1fe3c 100644
--- a/wp-includes/random_compat/random_bytes_openssl.php
+++ b/wp-includes/random_compat/random_bytes_openssl.php
@@ -41,9 +41,11 @@
  */
 function random_bytes($bytes)
 {
-    if (!is_int($bytes)) {
+    try {
+        $bytes = RandomCompat_intval($bytes);
+    } catch (TypeError $ex) {
         throw new TypeError(
-            'Length must be an integer'
+            'random_bytes(): $bytes must be an integer'
         );
     }
     if ($bytes < 1) {
diff --git a/wp-includes/random_compat/random_int.php b/wp-includes/random_compat/random_int.php
index 7fd50e7efd..6c91dbc516 100644
--- a/wp-includes/random_compat/random_int.php
+++ b/wp-includes/random_compat/random_int.php
@@ -40,21 +40,34 @@ function random_int($min, $max)
 {
     /**
      * Type and input logic checks
+     * 
+     * If you pass it a float in the range (~PHP_INT_MAX, PHP_INT_MAX)
+     * (non-inclusive), it will sanely cast it to an int. If you it's equal to
+     * ~PHP_INT_MAX or PHP_INT_MAX, we let it fail as not an integer. Floats 
+     * lose precision, so the <= and => operators might accidentally let a float
+     * through.
      */
-    if (!is_numeric($min)) {
+    
+    try {
+        $min = RandomCompat_intval($min);
+    } catch (TypeError $ex) {
         throw new TypeError(
             'random_int(): $min must be an integer'
         );
     }
-    if (!is_numeric($max)) {
+    try {
+        $max = RandomCompat_intval($max);
+    } catch (TypeError $ex) {
         throw new TypeError(
             'random_int(): $max must be an integer'
         );
     }
-
-    $min = (int) $min;
-    $max = (int) $max;
-
+    
+    /**
+     * Now that we've verified our weak typing system has given us an integer,
+     * let's validate the logic then we can move forward with generating random
+     * integers along a given range.
+     */
     if ($min > $max) {
         throw new Error(
             'Minimum value must be less than or equal to the maximum value'
@@ -164,7 +177,7 @@ function random_int($min, $max)
         /**
          * If $val overflows to a floating point number,
          * ... or is larger than $max,
-         * ... or smaller than $int,
+         * ... or smaller than $min,
          * then try again.
          */
     } while (!is_int($val) || $val > $max || $val < $min);