first commit -> move some files from one-api

vendor/aws_sdk/Aws/Crypto/Polyfill/Key.php

@@ -0,0 +1,77 @@
+<?php
+namespace Aws\Crypto\Polyfill;
+
+/**
+ * Class Key
+ *
+ * Wraps a string to keep it hidden from stack traces.
+ *
+ * @package Aws\Crypto\Polyfill
+ */
+class Key
+{
+    /**
+     * @var string $internalString
+     */
+    private $internalString;
+
+    /**
+     * Hide contents of 
+     *
+     * @return array
+     */
+    public function __debugInfo()
+    {
+        return [];
+    }
+
+    /**
+     * Key constructor.
+     * @param string $str
+     */
+    public function __construct($str)
+    {
+        $this->internalString = $str;
+    }
+
+    /**
+     * Defense in depth:
+     *
+     * PHP 7.2 includes the Sodium cryptography library, which (among other things)
+     * exposes a function called sodium_memzero() that we can use to zero-fill strings
+     * to minimize the risk of sensitive cryptographic materials persisting in memory.
+     *
+     * If this function is not available, we XOR the string in-place with itself as a
+     * best-effort attempt.
+     */
+    public function __destruct()
+    {
+        if (extension_loaded('sodium') && function_exists('sodium_memzero')) {
+            try {
+                \sodium_memzero($this->internalString);
+            } catch (\SodiumException $ex) {
+                // This is a best effort, but does not provide the same guarantees as sodium_memzero():
+                $this->internalString ^= $this->internalString;
+            }
+        }
+    }
+
+    /**
+     * @return string
+     */
+    public function get()
+    {
+        return $this->internalString;
+    }
+
+    /**
+     * @return int
+     */
+    public function length()
+    {
+        if (\is_callable('\\mb_strlen')) {
+            return (int) \mb_strlen($this->internalString, '8bit');
+        }
+        return (int) \strlen($this->internalString);
+    }
+}