formidable / classes / helpers / FrmSerializedStringParserHelper.php

FrmSerializedStringParserHelper.php in Formidable Forms – WordPress Form Builder for Contact Forms, Calculators, Quizzes & More 6.8.3, at classes/helpers/FrmSerializedStringParserHelper.php

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1	<?php
2
3	if ( ! defined( 'ABSPATH' ) ) {
4	die( 'You are not allowed to call this page directly.' );
5	}
6
7	/**
8	* Parses serialized strings without using the unsafe unserialize function.
9	*
10	* @since 6.2
11	*/
12	class FrmSerializedStringParserHelper {
13
14	/**
15	* @var FrmSerializedStringParserHelper\|null
16	*/
17	private static $instance;
18
19	/**
20	* Get a singleton instance of the parser.
21	*
22	* @return FrmSerializedStringParserHelper
23	*/
24	public static function get() {
25	if ( ! isset( self::$instance ) ) {
26	self::$instance = new self();
27	}
28	return self::$instance;
29	}
30
31	/**
32	* Private constructor to enforce the use of FrmSerializedStringParserHelper::get.
33	*/
34	private function __construct() {}
35
36	/**
37	* Parse a string containing a serialized data structure.
38	* This is the initial entry point into the recursive parser.
39	*
40	* @param string $string
41	* @return mixed
42	*/
43	public function parse( $string ) {
44	return $this->do_parse( new FrmStringReaderHelper( $string ) );
45	}
46
47	/**
48	* This is the recursive parser.
49	*
50	* @param FrmStringReaderHelper $string
51	* @return mixed
52	*/
53	private function do_parse( $string ) {
54	$val = null;
55
56	// May be : or ; as a terminator, depending on what the data type is.
57	$type = substr( $string->read( 2 ), 0, 1 );
58
59	switch ( $type ) {
60	case 'a':
61	// Associative array: a:length:{[index][value]...}
62	$count = (int) $string->read_until( ':' );
63
64	// Eat the opening "{" of the array.
65	$string->read( 1 );
66
67	$val = array();
68	for ( $i = 0; $i < $count; $i++ ) {
69	$array_key = $this->do_parse( $string );
70	$array_value = $this->do_parse( $string );
71
72	if ( ! is_array( $array_key ) ) {
73	$val[ $array_key ] = $array_value;
74	}
75	}
76
77	// Eat "}" terminating the array.
78	$string->read( 1 );
79	break;
80
81	case 's':
82	$len = (int) $string->read_until( ':' );
83	$val = $string->read( $len + 2 );
84
85	// Eat the separator.
86	$string->read( 1 );
87	break;
88
89	case 'i':
90	$val = (int) $string->read_until( ';' );
91	break;
92
93	case 'd':
94	$val = (float) $string->read_until( ';' );
95	break;
96
97	case 'b':
98	// Boolean is 0 or 1.
99	$bool = $string->read( 2 );
100	$val = substr( $bool, 0, 1 ) == '1';
101	break;
102
103	default:
104	// Includes case 'N' and case 'O'.
105	// Treat a serialized object or anything unexpected as Null.
106	$val = null;
107	break;
108	}//end switch
109
110	return $val;
111	}
112	}
113