Key.php — Transferito: WP Migration trunk

transferito / vendor / aws / aws-sdk-php / src / Crypto / Polyfill / Key.php

transferito / vendor / aws / aws-sdk-php / src / Crypto / Polyfill Last commit date

Key.php

78 lines

1	<?php
2	namespace Aws\Crypto\Polyfill;
3
4	/**
5	* Class Key
6	*
7	* Wraps a string to keep it hidden from stack traces.
8	*
9	* @package Aws\Crypto\Polyfill
10	*/
11	class Key
12	{
13	/**
14	* @var string $internalString
15	*/
16	private $internalString;
17
18	/**
19	* Hide contents of
20	*
21	* @return array
22	*/
23	public function __debugInfo()
24	{
25	return [];
26	}
27
28	/**
29	* Key constructor.
30	* @param string $str
31	*/
32	public function __construct($str)
33	{
34	$this->internalString = $str;
35	}
36
37	/**
38	* Defense in depth:
39	*
40	* PHP 7.2 includes the Sodium cryptography library, which (among other things)
41	* exposes a function called sodium_memzero() that we can use to zero-fill strings
42	* to minimize the risk of sensitive cryptographic materials persisting in memory.
43	*
44	* If this function is not available, we XOR the string in-place with itself as a
45	* best-effort attempt.
46	*/
47	public function __destruct()
48	{
49	if (extension_loaded('sodium') && function_exists('sodium_memzero')) {
50	try {
51	\sodium_memzero($this->internalString);
52	} catch (\SodiumException $ex) {
53	// This is a best effort, but does not provide the same guarantees as sodium_memzero():
54	$this->internalString ^= $this->internalString;
55	}
56	}
57	}
58
59	/**
60	* @return string
61	*/
62	public function get()
63	{
64	return $this->internalString;
65	}
66
67	/**
68	* @return int
69	*/
70	public function length()
71	{
72	if (\is_callable('\\mb_strlen')) {
73	return (int) \mb_strlen($this->internalString, '8bit');
74	}
75	return (int) \strlen($this->internalString);
76	}
77	}
78