1 <?php
2 
3 /**
4  * Class EmailAddressValidator
5  *
6  * @link https://github.com/aziraphale/email-address-validator
7  * @link http://code.google.com/p/php-email-address-validation/
8  * @license New BSD license http://www.opensource.org/licenses/bsd-license.php
9  * @example if (EmailAddressValidator::checkEmailAddress('test@example.org')) {
10  * @example     // Email address is technically valid
11  * @example }
12  */
13 class EmailAddressValidator
14 {
15     /**
16      * Check email address validity
17      * @param string $emailAddress Email address to be checked
18      * @param bool $allowLocal allow local domains
19      * @return bool Whether email is valid
20      */
21     public static function checkEmailAddress($emailAddress, $allowLocal = false)
22     {
23         // If magic quotes is "on", email addresses with quote marks will
24         // fail validation because of added escape characters. Uncommenting
25         // the next three lines will allow for this issue.
26         //if (get_magic_quotes_gpc()) {
27         //    $emailAddress = stripslashes($emailAddress);
28         //}
29 
30         // Control characters are not allowed
31         if (preg_match('/[\x00-\x1F\x7F-\xFF]/', $emailAddress)) {
32             return false;
33         }
34 
35         // Check email length - min 3 (a@a), max 256
36         if (!self::checkTextLength($emailAddress, 3, 256)) {
37             return false;
38         }
39 
40         // Split it into sections using last instance of "@"
41         $atSymbol = strrpos($emailAddress, '@');
42         if ($atSymbol === false) {
43             // No "@" symbol in email.
44             return false;
45         }
46         $emailAddressParts[0] = substr($emailAddress, 0, $atSymbol);
47         $emailAddressParts[1] = substr($emailAddress, $atSymbol + 1);
48 
49         // Count the "@" symbols. Only one is allowed, except where
50         // contained in quote marks in the local part. Quickest way to
51         // check this is to remove anything in quotes. We also remove
52         // characters escaped with backslash, and the backslash
53         // character.
54         $tempAddressParts[0] = preg_replace('/\./', '', $emailAddressParts[0]);
55         $tempAddressParts[0] = preg_replace('/"[^"]+"/', '', $tempAddressParts[0]);
56         $tempAddressParts[1] = $emailAddressParts[1];
57         $tempAddress = $tempAddressParts[0] . $tempAddressParts[1];
58         // Then check - should be no "@" symbols.
59         if (strrpos($tempAddress, '@') !== false) {
60             // "@" symbol found
61             return false;
62         }
63 
64         // Check local portion
65         if (!self::checkLocalPortion($emailAddressParts[0])) {
66             return false;
67         }
68 
69         // Check domain portion
70         if (!self::checkDomainPortion($emailAddressParts[1], $allowLocal)) {
71             return false;
72         }
73 
74         // If we're still here, all checks above passed. Email is valid.
75         return true;
76     }
77 
78     /**
79      * Checks email section before "@" symbol for validity
80      * @param string $localPortion Text to be checked
81      * @return bool Whether local portion is valid
82      */
83     public static function checkLocalPortion($localPortion)
84     {
85         // Local portion can only be from 1 to 64 characters, inclusive.
86         // Please note that servers are encouraged to accept longer local
87         // parts than 64 characters.
88         if (!self::checkTextLength($localPortion, 1, 64)) {
89             return false;
90         }
91         // Local portion must be:
92         // 1) a dot-atom (strings separated by periods)
93         // 2) a quoted string
94         // 3) an obsolete format string (combination of the above)
95         $localPortionParts = explode('.', $localPortion);
96         for ($i = 0, $max = sizeof($localPortionParts); $i < $max; $i++) {
97              if (!preg_match('.^('
98                             .    '([A-Za-z0-9!#$%&\'*+/=?^_`{|}~-]'
99                             .    '[A-Za-z0-9!#$%&\'*+/=?^_`{|}~-]{0,63})'
100                             .'|'
101                             .    '("[^\\\"]{0,62}")'
102                             .')$.'
103                             ,$localPortionParts[$i])) {
104                 return false;
105             }
106         }
107         return true;
108     }
109 
110     /**
111      * Checks email section after "@" symbol for validity
112      * @param string $domainPortion Text to be checked
113      * @param bool $allowLocal allow local domains?
114      * @return bool Whether domain portion is valid
115      */
116     public static function checkDomainPortion($domainPortion, $allowLocal = false)
117     {
118         // Total domain can only be from 1 to 255 characters, inclusive
119         if (!self::checkTextLength($domainPortion, 1, 255)) {
120             return false;
121         }
122 
123         // some IPv4/v6 regexps borrowed from Feyd
124         // see: http://forums.devnetwork.net/viewtopic.php?f=38&t=53479
125         $dec_octet = '(?:25[0-5]|2[0-4]\d|1\d\d|[1-9]\d|[0-9])';
126         $hex_digit = '[A-Fa-f0-9]';
127         $h16 = "{$hex_digit}{1,4}";
128         $IPv4Address = "$dec_octet\\.$dec_octet\\.$dec_octet\\.$dec_octet";
129         $ls32 = "(?:$h16:$h16|$IPv4Address)";
130         $IPv6Address =
131             "(?:(?:{$IPv4Address})|(?:" .
132             "(?:$h16:){6}$ls32" .
133             "|::(?:$h16:){5}$ls32" .
134             "|(?:$h16)?::(?:$h16:){4}$ls32" .
135             "|(?:(?:$h16:){0,1}$h16)?::(?:$h16:){3}$ls32" .
136             "|(?:(?:$h16:){0,2}$h16)?::(?:$h16:){2}$ls32" .
137             "|(?:(?:$h16:){0,3}$h16)?::(?:$h16:){1}$ls32" .
138             "|(?:(?:$h16:){0,4}$h16)?::$ls32" .
139             "|(?:(?:$h16:){0,5}$h16)?::$h16" .
140             "|(?:(?:$h16:){0,6}$h16)?::" .
141             ")(?:\\/(?:12[0-8]|1[0-1][0-9]|[1-9][0-9]|[0-9]))?)";
142 
143         if (preg_match("/^($IPv4Address|\\[$IPv4Address\\]|\\[$IPv6Address\\])$/",
144                             $domainPortion)){
145             return true;
146         } else {
147             $domainPortionParts = explode('.', $domainPortion);
148             if (!$allowLocal && sizeof($domainPortionParts) < 2) {
149                 return false; // Not enough parts to domain
150             }
151             for ($i = 0, $max = sizeof($domainPortionParts); $i < $max; $i++) {
152                 // Each portion must be between 1 and 63 characters, inclusive
153                 if (!self::checkTextLength($domainPortionParts[$i], 1, 63)) {
154                     return false;
155                 }
156                 if (!preg_match('/^(([A-Za-z0-9][A-Za-z0-9-]{0,61}[A-Za-z0-9])|'
157                    .'([A-Za-z0-9]+))$/', $domainPortionParts[$i])) {
158                     return false;
159                 }
160                 if ($i == $max - 1) { // TLD cannot be only numbers
161                     if (strlen(preg_replace('/[0-9]/', '', $domainPortionParts[$i])) <= 0) {
162                         return false;
163                     }
164                 }
165             }
166         }
167         return true;
168     }
169 
170     /**
171      * Check given text length is between defined bounds
172      * @param string $text Text to be checked
173      * @param int $minimum Minimum acceptable length
174      * @param int $maximum Maximum acceptable length
175      * @return bool Whether string is within bounds (inclusive)
176      */
177     protected static function checkTextLength($text, $minimum, $maximum)
178     {
179         // Minimum and maximum are both inclusive
180         $textLength = strlen($text);
181         return ($textLength >= $minimum && $textLength <= $maximum);
182     }
183 }
184