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 */
13class 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