1
|
|
|
<?php |
2
|
|
|
|
3
|
|
|
declare(strict_types=1); |
4
|
|
|
|
5
|
|
|
namespace EmailValidator\Validator\Domain; |
6
|
|
|
|
7
|
|
|
/** |
8
|
|
|
* Validates domain names according to RFC 5322 standards |
9
|
|
|
*/ |
10
|
|
|
class DomainNameValidator |
11
|
|
|
{ |
12
|
|
|
private const MAX_DOMAIN_LABEL_LENGTH = 63; |
13
|
|
|
private const MAX_DOMAIN_LENGTH = 255; |
14
|
|
|
|
15
|
|
|
/** |
16
|
|
|
* Validates a domain name |
17
|
|
|
* |
18
|
|
|
* @param string $domain The domain name to validate |
19
|
|
|
* @return bool True if the domain name is valid |
20
|
|
|
*/ |
21
|
|
|
public function validate(string $domain): bool |
22
|
|
|
{ |
23
|
|
|
// Check for empty domain |
24
|
|
|
if ($domain === '') { |
25
|
|
|
return false; |
26
|
|
|
} |
27
|
|
|
|
28
|
|
|
// Check total length |
29
|
|
|
if (!$this->validateLength($domain)) { |
30
|
|
|
return false; |
31
|
|
|
} |
32
|
|
|
|
33
|
|
|
// Split into labels |
34
|
|
|
$labels = explode('.', $domain); |
35
|
|
|
|
36
|
|
|
// Must have at least two labels |
37
|
|
|
if (count($labels) < 2) { |
38
|
|
|
return false; |
39
|
|
|
} |
40
|
|
|
|
41
|
|
|
// Validate each label |
42
|
|
|
foreach ($labels as $label) { |
43
|
|
|
if (!$this->validateLabel($label)) { |
44
|
|
|
return false; |
45
|
|
|
} |
46
|
|
|
} |
47
|
|
|
|
48
|
|
|
return true; |
49
|
|
|
} |
50
|
|
|
|
51
|
|
|
/** |
52
|
|
|
* Validates the length of a domain |
53
|
|
|
* |
54
|
|
|
* @param string $domain The domain to validate |
55
|
|
|
* @return bool True if the length is valid |
56
|
|
|
*/ |
57
|
|
|
private function validateLength(string $domain): bool |
58
|
|
|
{ |
59
|
|
|
return strlen($domain) <= self::MAX_DOMAIN_LENGTH; |
60
|
|
|
} |
61
|
|
|
|
62
|
|
|
/** |
63
|
|
|
* Validates a single domain label |
64
|
|
|
* |
65
|
|
|
* @param string $label The domain label to validate |
66
|
|
|
* @return bool True if the domain label is valid |
67
|
|
|
*/ |
68
|
|
|
private function validateLabel(string $label): bool |
69
|
|
|
{ |
70
|
|
|
// Check length |
71
|
|
|
if (!$this->validateLabelLength($label)) { |
72
|
|
|
return false; |
73
|
|
|
} |
74
|
|
|
|
75
|
|
|
// Handle IDN labels (starting with 'xn--') |
76
|
|
|
if (substr($label, 0, 4) === 'xn--') { |
77
|
|
|
return $this->validateIDNLabel($label); |
78
|
|
|
} |
79
|
|
|
|
80
|
|
|
// Single character labels are allowed if they're alphanumeric |
81
|
|
|
if (strlen($label) === 1) { |
82
|
|
|
return ctype_alnum($label); |
83
|
|
|
} |
84
|
|
|
|
85
|
|
|
// Must start and end with alphanumeric |
86
|
|
|
if (!$this->hasValidLabelBoundaries($label)) { |
87
|
|
|
return false; |
88
|
|
|
} |
89
|
|
|
|
90
|
|
|
// Check for valid characters and format |
91
|
|
|
if (!$this->hasValidLabelFormat($label)) { |
92
|
|
|
return false; |
93
|
|
|
} |
94
|
|
|
|
95
|
|
|
// Check for consecutive hyphens |
96
|
|
|
return !$this->hasConsecutiveHyphens($label); |
97
|
|
|
} |
98
|
|
|
|
99
|
|
|
/** |
100
|
|
|
* Validates the length of a domain label |
101
|
|
|
* |
102
|
|
|
* @param string $label The domain label to validate |
103
|
|
|
* @return bool True if the length is valid |
104
|
|
|
*/ |
105
|
|
|
private function validateLabelLength(string $label): bool |
106
|
|
|
{ |
107
|
|
|
return strlen($label) <= self::MAX_DOMAIN_LABEL_LENGTH && $label !== ''; |
108
|
|
|
} |
109
|
|
|
|
110
|
|
|
/** |
111
|
|
|
* Validates an IDN (Internationalized Domain Name) label |
112
|
|
|
* |
113
|
|
|
* @param string $label The IDN label to validate |
114
|
|
|
* @return bool True if the IDN label is valid |
115
|
|
|
*/ |
116
|
|
|
private function validateIDNLabel(string $label): bool |
117
|
|
|
{ |
118
|
|
|
// Must be at least 5 characters (xn-- plus at least one character) |
119
|
|
|
if (strlen($label) < 5) { |
120
|
|
|
return false; |
121
|
|
|
} |
122
|
|
|
|
123
|
|
|
// Rest of the label must be alphanumeric or hyphen |
124
|
|
|
$rest = substr($label, 4); |
125
|
|
|
return (bool)preg_match('/^[a-zA-Z0-9-]+$/', $rest); |
126
|
|
|
} |
127
|
|
|
|
128
|
|
|
/** |
129
|
|
|
* Checks if a domain label has valid start and end characters |
130
|
|
|
* |
131
|
|
|
* @param string $label The domain label to validate |
132
|
|
|
* @return bool True if the boundaries are valid |
133
|
|
|
*/ |
134
|
|
|
private function hasValidLabelBoundaries(string $label): bool |
135
|
|
|
{ |
136
|
|
|
return ctype_alnum($label[0]) && ctype_alnum(substr($label, -1)); |
137
|
|
|
} |
138
|
|
|
|
139
|
|
|
/** |
140
|
|
|
* Checks if a domain label has valid format |
141
|
|
|
* |
142
|
|
|
* @param string $label The domain label to validate |
143
|
|
|
* @return bool True if the format is valid |
144
|
|
|
*/ |
145
|
|
|
private function hasValidLabelFormat(string $label): bool |
146
|
|
|
{ |
147
|
|
|
return (bool)preg_match('/^[a-zA-Z0-9][a-zA-Z0-9-]*[a-zA-Z0-9]$/', $label); |
148
|
|
|
} |
149
|
|
|
|
150
|
|
|
/** |
151
|
|
|
* Checks if a domain label has consecutive hyphens |
152
|
|
|
* |
153
|
|
|
* @param string $label The domain label to validate |
154
|
|
|
* @return bool True if the label has consecutive hyphens |
155
|
|
|
*/ |
156
|
|
|
private function hasConsecutiveHyphens(string $label): bool |
157
|
|
|
{ |
158
|
|
|
return strpos($label, '--') !== false; |
159
|
|
|
} |
160
|
|
|
} |