Extends yii\base\Security::generateRandomKey() to use suspicious OpenSSL setups

Security.php

<?php

namespace yourapp;

use yii\helpers\StringHelper;

class Security extends \yii\base\Security
{
    /**
     * Extends yii\base\Security::generateRandomKey() to use suspicious OpenSSL setups if
     * all else fails.
     *
     * @inheritdoc
     */
    public function generateRandomKey($length = 32)
    {
        try {
            $key = parent::generateRandomKey($length);

            if (!empty($key) && StringHelper::byteLength($key) === $length) {
                return $key;
            }
        } catch (\Exception $ignore) {
            $key = openssl_random_pseudo_bytes($length, $cryptoStrong);
            if ($cryptoStrong === false) {
                throw new \Exception(
                    'openssl_random_pseudo_bytes() set $crypto_strong false. Your PHP setup is insecure.'
                );
            }

            if ($key !== false && StringHelper::byteLength($key) === $length) {
                return $key;
            }
        }

        throw new \Exception('Unable to generate a random key');
    }
}