File: //proc/self/cwd/wp-content/plugins/sendgrid-email-delivery-simplified/vendor/is_mail.php
<?php
/**
* To validate an email address according to RFCs 5321, 5322 and others
*
* Copyright © 2008-2011, Dominic Sayers <br>
* Test schema documentation Copyright © 2011, Daniel Marschall <br>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification,
* are permitted provided that the following conditions are met:
*
* - Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* - Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
* - Neither the name of Dominic Sayers nor the names of its contributors may be
* used to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
* ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
* ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* @package is_email
* @author Dominic Sayers <dominic@sayers.cc>
* @copyright 2008-2011 Dominic Sayers
* @license http://www.opensource.org/licenses/bsd-license.php BSD License
* @link http://www.dominicsayers.com/isemail
* @version 3.04.1 - Changed my link to http://isemail.info throughout
*/
// The quality of this code has been improved greatly by using PHPLint
// Copyright (c) 2010 Umberto Salsi
// This is free software; see the license for copying conditions.
// More info: http://www.icosaedro.it/phplint/
/*.
require_module 'standard';
require_module 'pcre';
.*/
if (!defined('ISEMAIL_VALID')) {
/*:diagnostic constants start:*/
// This part of the code is generated using data from test/meta.xml. Beware of making manual alterations
// Categories
define('ISEMAIL_VALID_CATEGORY', 1);
define('ISEMAIL_DNSWARN', 7);
define('ISEMAIL_RFC5321', 15);
define('ISEMAIL_CFWS', 31);
define('ISEMAIL_DEPREC', 63);
define('ISEMAIL_RFC5322', 127);
define('ISEMAIL_ERR', 255);
// Diagnoses
// Address is valid
define('ISEMAIL_VALID', 0);
// Address is valid but a DNS check was not successful
define('ISEMAIL_DNSWARN_NO_MX_RECORD', 5);
define('ISEMAIL_DNSWARN_NO_RECORD', 6);
// Address is valid for SMTP but has unusual elements
define('ISEMAIL_RFC5321_TLD', 9);
define('ISEMAIL_RFC5321_TLDNUMERIC', 10);
define('ISEMAIL_RFC5321_QUOTEDSTRING', 11);
define('ISEMAIL_RFC5321_ADDRESSLITERAL', 12);
define('ISEMAIL_RFC5321_IPV6DEPRECATED', 13);
// Address is valid within the message but cannot be used unmodified for the envelope
define('ISEMAIL_CFWS_COMMENT', 17);
define('ISEMAIL_CFWS_FWS', 18);
// Address contains deprecated elements but may still be valid in restricted contexts
define('ISEMAIL_DEPREC_LOCALPART', 33);
define('ISEMAIL_DEPREC_FWS', 34);
define('ISEMAIL_DEPREC_QTEXT', 35);
define('ISEMAIL_DEPREC_QP', 36);
define('ISEMAIL_DEPREC_COMMENT', 37);
define('ISEMAIL_DEPREC_CTEXT', 38);
define('ISEMAIL_DEPREC_CFWS_NEAR_AT', 49);
// The address is only valid according to the broad definition of RFC 5322. It is otherwise invalid.
define('ISEMAIL_RFC5322_DOMAIN', 65);
define('ISEMAIL_RFC5322_TOOLONG', 66);
define('ISEMAIL_RFC5322_LOCAL_TOOLONG', 67);
define('ISEMAIL_RFC5322_DOMAIN_TOOLONG', 68);
define('ISEMAIL_RFC5322_LABEL_TOOLONG', 69);
define('ISEMAIL_RFC5322_DOMAINLITERAL', 70);
define('ISEMAIL_RFC5322_DOMLIT_OBSDTEXT', 71);
define('ISEMAIL_RFC5322_IPV6_GRPCOUNT', 72);
define('ISEMAIL_RFC5322_IPV6_2X2XCOLON', 73);
define('ISEMAIL_RFC5322_IPV6_BADCHAR', 74);
define('ISEMAIL_RFC5322_IPV6_MAXGRPS', 75);
define('ISEMAIL_RFC5322_IPV6_COLONSTRT', 76);
define('ISEMAIL_RFC5322_IPV6_COLONEND', 77);
// Address is invalid for any purpose
define('ISEMAIL_ERR_EXPECTING_DTEXT', 129);
define('ISEMAIL_ERR_NOLOCALPART', 130);
define('ISEMAIL_ERR_NODOMAIN', 131);
define('ISEMAIL_ERR_CONSECUTIVEDOTS', 132);
define('ISEMAIL_ERR_ATEXT_AFTER_CFWS', 133);
define('ISEMAIL_ERR_ATEXT_AFTER_QS', 134);
define('ISEMAIL_ERR_ATEXT_AFTER_DOMLIT', 135);
define('ISEMAIL_ERR_EXPECTING_QPAIR', 136);
define('ISEMAIL_ERR_EXPECTING_ATEXT', 137);
define('ISEMAIL_ERR_EXPECTING_QTEXT', 138);
define('ISEMAIL_ERR_EXPECTING_CTEXT', 139);
define('ISEMAIL_ERR_BACKSLASHEND', 140);
define('ISEMAIL_ERR_DOT_START', 141);
define('ISEMAIL_ERR_DOT_END', 142);
define('ISEMAIL_ERR_DOMAINHYPHENSTART', 143);
define('ISEMAIL_ERR_DOMAINHYPHENEND', 144);
define('ISEMAIL_ERR_UNCLOSEDQUOTEDSTR', 145);
define('ISEMAIL_ERR_UNCLOSEDCOMMENT', 146);
define('ISEMAIL_ERR_UNCLOSEDDOMLIT', 147);
define('ISEMAIL_ERR_FWS_CRLF_X2', 148);
define('ISEMAIL_ERR_FWS_CRLF_END', 149);
define('ISEMAIL_ERR_CR_NO_LF', 150);
// End of generated code
/*:diagnostic constants end:*/
// function control
define('ISEMAIL_THRESHOLD' , 16);
// Email parts
define('ISEMAIL_COMPONENT_LOCALPART' , 0);
define('ISEMAIL_COMPONENT_DOMAIN' , 1);
define('ISEMAIL_COMPONENT_LITERAL' , 2);
define('ISEMAIL_CONTEXT_COMMENT' , 3);
define('ISEMAIL_CONTEXT_FWS' , 4);
define('ISEMAIL_CONTEXT_QUOTEDSTRING' , 5);
define('ISEMAIL_CONTEXT_QUOTEDPAIR' , 6);
// Miscellaneous string constants
define('ISEMAIL_STRING_AT' , '@');
define('ISEMAIL_STRING_BACKSLASH' , '\\');
define('ISEMAIL_STRING_DOT' , '.');
define('ISEMAIL_STRING_DQUOTE' , '"');
define('ISEMAIL_STRING_OPENPARENTHESIS' , '(');
define('ISEMAIL_STRING_CLOSEPARENTHESIS', ')');
define('ISEMAIL_STRING_OPENSQBRACKET' , '[');
define('ISEMAIL_STRING_CLOSESQBRACKET' , ']');
define('ISEMAIL_STRING_HYPHEN' , '-');
define('ISEMAIL_STRING_COLON' , ':');
define('ISEMAIL_STRING_DOUBLECOLON' , '::');
define('ISEMAIL_STRING_SP' , ' ');
define('ISEMAIL_STRING_HTAB' , "\t");
define('ISEMAIL_STRING_CR' , "\r");
define('ISEMAIL_STRING_LF' , "\n");
define('ISEMAIL_STRING_IPV6TAG' , 'IPv6:');
// US-ASCII visible characters not valid for atext (http://tools.ietf.org/html/rfc5322#section-3.2.3)
define('ISEMAIL_STRING_SPECIALS' , '()<>[]:;@\\,."');
}
class SendGrid_ThirdParty {
/**
* Check that an email address conforms to RFCs 5321, 5322 and others
*
* As of Version 3.0, we are now distinguishing clearly between a Mailbox
* as defined by RFC 5321 and an addr-spec as defined by RFC 5322. Depending
* on the context, either can be regarded as a valid email address. The
* RFC 5321 Mailbox specification is more restrictive (comments, white space
* and obsolete forms are not allowed)
*
* @param string $email The email address to check
* @param boolean $checkDNS If true then a DNS check for MX records will be made
* @param mixed $errorlevel Determines the boundary between valid and invalid addresses.
* Status codes above this number will be returned as-is,
* status codes below will be returned as ISEMAIL_VALID. Thus the
* calling program can simply look for ISEMAIL_VALID if it is
* only interested in whether an address is valid or not. The
* errorlevel will determine how "picky" is_email() is about
* the address.
*
* If omitted or passed as false then is_email() will return
* true or false rather than an integer error or warning.
*
* NB Note the difference between $errorlevel = false and
* $errorlevel = 0
* @param array $parsedata If passed, returns the parsed address components
*/
/*.mixed.*/
public static function is_email($email, $checkDNS = false, $errorlevel = false, &$parsedata = array()) {
// Check that $email is a valid address. Read the following RFCs to understand the constraints:
// (http://tools.ietf.org/html/rfc5321)
// (http://tools.ietf.org/html/rfc5322)
// (http://tools.ietf.org/html/rfc4291#section-2.2)
// (http://tools.ietf.org/html/rfc1123#section-2.1)
// (http://tools.ietf.org/html/rfc3696) (guidance only)
// version 2.0: Enhance $diagnose parameter to $errorlevel
// version 3.0: Introduced status categories
// revision 3.1: BUG: $parsedata was passed by value instead of by reference
if (is_bool($errorlevel)) {
$threshold = ISEMAIL_VALID;
$diagnose = (bool) $errorlevel;
} else {
$diagnose = true;
switch ((int) $errorlevel) {
case E_WARNING: $threshold = ISEMAIL_THRESHOLD; break; // For backward compatibility
case E_ERROR: $threshold = ISEMAIL_VALID; break; // For backward compatibility
default: $threshold = (int) $errorlevel;
}
}
$return_status = array(ISEMAIL_VALID);
// Parse the address into components, character by character
$raw_length = strlen($email);
$context = ISEMAIL_COMPONENT_LOCALPART; // Where we are
$context_stack = array($context); // Where we have been
$context_prior = ISEMAIL_COMPONENT_LOCALPART; // Where we just came from
$token = ''; // The current character
$token_prior = ''; // The previous character
$parsedata = array(
ISEMAIL_COMPONENT_LOCALPART => '',
ISEMAIL_COMPONENT_DOMAIN => ''
); // For the components of the address
$atomlist = array(
ISEMAIL_COMPONENT_LOCALPART => array(''),
ISEMAIL_COMPONENT_DOMAIN => array('')
); // For the dot-atom elements of the address
$element_count = 0;
$element_len = 0;
$hyphen_flag = false; // Hyphen cannot occur at the end of a subdomain
$end_or_die = false; // CFWS can only appear at the end of the element
//-echo "<table style=\"clear:left;\">"; // debug
for ($i = 0; $i < $raw_length; $i++) {
$token = $email[$i];
//-echo "<tr><td><strong>$context|",(($end_or_die) ? 'true' : 'false'),"|$token|" . max($return_status) . "</strong></td>"; // debug
switch ($context) {
//-------------------------------------------------------------
// local-part
//-------------------------------------------------------------
case ISEMAIL_COMPONENT_LOCALPART:
// http://tools.ietf.org/html/rfc5322#section-3.4.1
// local-part = dot-atom / quoted-string / obs-local-part
//
// dot-atom = [CFWS] dot-atom-text [CFWS]
//
// dot-atom-text = 1*atext *("." 1*atext)
//
// quoted-string = [CFWS]
// DQUOTE *([FWS] qcontent) [FWS] DQUOTE
// [CFWS]
//
// obs-local-part = word *("." word)
//
// word = atom / quoted-string
//
// atom = [CFWS] 1*atext [CFWS]
switch ($token) {
// Comment
case ISEMAIL_STRING_OPENPARENTHESIS:
if ($element_len === 0)
// Comments are OK at the beginning of an element
$return_status[] = ($element_count === 0) ? ISEMAIL_CFWS_COMMENT : ISEMAIL_DEPREC_COMMENT;
else {
$return_status[] = ISEMAIL_CFWS_COMMENT;
$end_or_die = true; // We can't start a comment in the middle of an element, so this better be the end
}
$context_stack[] = $context;
$context = ISEMAIL_CONTEXT_COMMENT;
break;
// Next dot-atom element
case ISEMAIL_STRING_DOT:
if ($element_len === 0)
// Another dot, already?
$return_status[] = ($element_count === 0) ? ISEMAIL_ERR_DOT_START : ISEMAIL_ERR_CONSECUTIVEDOTS; // Fatal error
else
// The entire local-part can be a quoted string for RFC 5321
// If it's just one atom that is quoted then it's an RFC 5322 obsolete form
if ($end_or_die) $return_status[] = ISEMAIL_DEPREC_LOCALPART;
$end_or_die = false; // CFWS & quoted strings are OK again now we're at the beginning of an element (although they are obsolete forms)
$element_len = 0;
$element_count++;
$parsedata[ISEMAIL_COMPONENT_LOCALPART] .= $token;
$atomlist[ISEMAIL_COMPONENT_LOCALPART][$element_count] = '';
break;
// Quoted string
case ISEMAIL_STRING_DQUOTE:
if ($element_len === 0) {
// The entire local-part can be a quoted string for RFC 5321
// If it's just one atom that is quoted then it's an RFC 5322 obsolete form
$return_status[] = ($element_count === 0) ? ISEMAIL_RFC5321_QUOTEDSTRING : ISEMAIL_DEPREC_LOCALPART;
$parsedata[ISEMAIL_COMPONENT_LOCALPART] .= $token;
$atomlist[ISEMAIL_COMPONENT_LOCALPART][$element_count] .= $token;
$element_len++;
$end_or_die = true; // Quoted string must be the entire element
$context_stack[] = $context;
$context = ISEMAIL_CONTEXT_QUOTEDSTRING;
} else {
$return_status[] = ISEMAIL_ERR_EXPECTING_ATEXT; // Fatal error
}
break;
// Folding White Space
case ISEMAIL_STRING_CR:
case ISEMAIL_STRING_SP:
case ISEMAIL_STRING_HTAB:
if (($token === ISEMAIL_STRING_CR) && ((++$i === $raw_length) || ($email[$i] !== ISEMAIL_STRING_LF))) {$return_status[] = ISEMAIL_ERR_CR_NO_LF; break;} // Fatal error
if ($element_len === 0)
$return_status[] = ($element_count === 0) ? ISEMAIL_CFWS_FWS : ISEMAIL_DEPREC_FWS;
else
$end_or_die = true; // We can't start FWS in the middle of an element, so this better be the end
$context_stack[] = $context;
$context = ISEMAIL_CONTEXT_FWS;
$token_prior = $token;
break;
// @
case ISEMAIL_STRING_AT:
// At this point we should have a valid local-part
if (count($context_stack) !== 1) die('Unexpected item on context stack');
if ($parsedata[ISEMAIL_COMPONENT_LOCALPART] === '')
$return_status[] = ISEMAIL_ERR_NOLOCALPART; // Fatal error
elseif ($element_len === 0) $return_status[] = ISEMAIL_ERR_DOT_END; // Fatal error
// http://tools.ietf.org/html/rfc5321#section-4.5.3.1.1
// The maximum total length of a user name or other local-part is 64
// octets.
elseif (strlen($parsedata[ISEMAIL_COMPONENT_LOCALPART]) > 64)
$return_status[] = ISEMAIL_RFC5322_LOCAL_TOOLONG;
// http://tools.ietf.org/html/rfc5322#section-3.4.1
// Comments and folding white space
// SHOULD NOT be used around the "@" in the addr-spec.
//
// http://tools.ietf.org/html/rfc2119
// 4. SHOULD NOT This phrase, or the phrase "NOT RECOMMENDED" mean that
// there may exist valid reasons in particular circumstances when the
// particular behavior is acceptable or even useful, but the full
// implications should be understood and the case carefully weighed
// before implementing any behavior described with this label.
elseif (($context_prior === ISEMAIL_CONTEXT_COMMENT) || ($context_prior === ISEMAIL_CONTEXT_FWS))
$return_status[] = ISEMAIL_DEPREC_CFWS_NEAR_AT;
// Clear everything down for the domain parsing
$context = ISEMAIL_COMPONENT_DOMAIN; // Where we are
$context_stack = array($context); // Where we have been
$element_count = 0;
$element_len = 0;
$end_or_die = false; // CFWS can only appear at the end of the element
break;
// atext
default:
// http://tools.ietf.org/html/rfc5322#section-3.2.3
// atext = ALPHA / DIGIT / ; Printable US-ASCII
// "!" / "#" / ; characters not including
// "$" / "%" / ; specials. Used for atoms.
// "&" / "'" /
// "*" / "+" /
// "-" / "/" /
// "=" / "?" /
// "^" / "_" /
// "`" / "{" /
// "|" / "}" /
// "~"
if ($end_or_die) {
// We have encountered atext where it is no longer valid
switch ($context_prior) {
case ISEMAIL_CONTEXT_COMMENT:
case ISEMAIL_CONTEXT_FWS:
$return_status[] = ISEMAIL_ERR_ATEXT_AFTER_CFWS;
break;
case ISEMAIL_CONTEXT_QUOTEDSTRING:
$return_status[] = ISEMAIL_ERR_ATEXT_AFTER_QS;
break;
default:
die ("More atext found where none is allowed, but unrecognised prior context: $context_prior");
}
} else {
$context_prior = $context;
$ord = ord($token);
if (($ord < 33) || ($ord > 126) || ($ord === 10) || (!is_bool(strpos(ISEMAIL_STRING_SPECIALS, $token))))
$return_status[] = ISEMAIL_ERR_EXPECTING_ATEXT; // Fatal error
$parsedata[ISEMAIL_COMPONENT_LOCALPART] .= $token;
$atomlist[ISEMAIL_COMPONENT_LOCALPART][$element_count] .= $token;
$element_len++;
}
}
break;
//-------------------------------------------------------------
// Domain
//-------------------------------------------------------------
case ISEMAIL_COMPONENT_DOMAIN:
// http://tools.ietf.org/html/rfc5322#section-3.4.1
// domain = dot-atom / domain-literal / obs-domain
//
// dot-atom = [CFWS] dot-atom-text [CFWS]
//
// dot-atom-text = 1*atext *("." 1*atext)
//
// domain-literal = [CFWS] "[" *([FWS] dtext) [FWS] "]" [CFWS]
//
// dtext = %d33-90 / ; Printable US-ASCII
// %d94-126 / ; characters not including
// obs-dtext ; "[", "]", or "\"
//
// obs-domain = atom *("." atom)
//
// atom = [CFWS] 1*atext [CFWS]
// http://tools.ietf.org/html/rfc5321#section-4.1.2
// Mailbox = Local-part "@" ( Domain / address-literal )
//
// Domain = sub-domain *("." sub-domain)
//
// address-literal = "[" ( IPv4-address-literal /
// IPv6-address-literal /
// General-address-literal ) "]"
// ; See Section 4.1.3
// http://tools.ietf.org/html/rfc5322#section-3.4.1
// Note: A liberal syntax for the domain portion of addr-spec is
// given here. However, the domain portion contains addressing
// information specified by and used in other protocols (e.g.,
// [RFC1034], [RFC1035], [RFC1123], [RFC5321]). It is therefore
// incumbent upon implementations to conform to the syntax of
// addresses for the context in which they are used.
// is_email() author's note: it's not clear how to interpret this in
// the context of a general email address validator. The conclusion I
// have reached is this: "addressing information" must comply with
// RFC 5321 (and in turn RFC 1035), anything that is "semantically
// invisible" must comply only with RFC 5322.
switch ($token) {
// Comment
case ISEMAIL_STRING_OPENPARENTHESIS:
if ($element_len === 0)
// Comments at the start of the domain are deprecated in the text
// Comments at the start of a subdomain are obs-domain
// (http://tools.ietf.org/html/rfc5322#section-3.4.1)
$return_status[] = ($element_count === 0) ? ISEMAIL_DEPREC_CFWS_NEAR_AT : ISEMAIL_DEPREC_COMMENT;
else {
$return_status[] = ISEMAIL_CFWS_COMMENT;
$end_or_die = true; // We can't start a comment in the middle of an element, so this better be the end
}
$context_stack[] = $context;
$context = ISEMAIL_CONTEXT_COMMENT;
break;
// Next dot-atom element
case ISEMAIL_STRING_DOT:
if ($element_len === 0)
// Another dot, already?
$return_status[] = ($element_count === 0) ? ISEMAIL_ERR_DOT_START : ISEMAIL_ERR_CONSECUTIVEDOTS; // Fatal error
elseif ($hyphen_flag)
// Previous subdomain ended in a hyphen
$return_status[] = ISEMAIL_ERR_DOMAINHYPHENEND; // Fatal error
else
// Nowhere in RFC 5321 does it say explicitly that the
// domain part of a Mailbox must be a valid domain according
// to the DNS standards set out in RFC 1035, but this *is*
// implied in several places. For instance, wherever the idea
// of host routing is discussed the RFC says that the domain
// must be looked up in the DNS. This would be nonsense unless
// the domain was designed to be a valid DNS domain. Hence we
// must conclude that the RFC 1035 restriction on label length
// also applies to RFC 5321 domains.
//
// http://tools.ietf.org/html/rfc1035#section-2.3.4
// labels 63 octets or less
if ($element_len > 63) $return_status[] = ISEMAIL_RFC5322_LABEL_TOOLONG;
$end_or_die = false; // CFWS is OK again now we're at the beginning of an element (although it may be obsolete CFWS)
$element_len = 0;
$element_count++;
$atomlist[ISEMAIL_COMPONENT_DOMAIN][$element_count] = '';
$parsedata[ISEMAIL_COMPONENT_DOMAIN] .= $token;
break;
// Domain literal
case ISEMAIL_STRING_OPENSQBRACKET:
if ($parsedata[ISEMAIL_COMPONENT_DOMAIN] === '') {
$end_or_die = true; // Domain literal must be the only component
$element_len++;
$context_stack[] = $context;
$context = ISEMAIL_COMPONENT_LITERAL;
$parsedata[ISEMAIL_COMPONENT_DOMAIN] .= $token;
$atomlist[ISEMAIL_COMPONENT_DOMAIN][$element_count] .= $token;
$parsedata[ISEMAIL_COMPONENT_LITERAL] = '';
} else {
$return_status[] = ISEMAIL_ERR_EXPECTING_ATEXT; // Fatal error
}
break;
// Folding White Space
case ISEMAIL_STRING_CR:
case ISEMAIL_STRING_SP:
case ISEMAIL_STRING_HTAB:
if (($token === ISEMAIL_STRING_CR) && ((++$i === $raw_length) || ($email[$i] !== ISEMAIL_STRING_LF))) {$return_status[] = ISEMAIL_ERR_CR_NO_LF; break;} // Fatal error
if ($element_len === 0)
$return_status[] = ($element_count === 0) ? ISEMAIL_DEPREC_CFWS_NEAR_AT : ISEMAIL_DEPREC_FWS;
else {
$return_status[] = ISEMAIL_CFWS_FWS;
$end_or_die = true; // We can't start FWS in the middle of an element, so this better be the end
}
$context_stack[] = $context;
$context = ISEMAIL_CONTEXT_FWS;
$token_prior = $token;
break;
// atext
default:
// RFC 5322 allows any atext...
// http://tools.ietf.org/html/rfc5322#section-3.2.3
// atext = ALPHA / DIGIT / ; Printable US-ASCII
// "!" / "#" / ; characters not including
// "$" / "%" / ; specials. Used for atoms.
// "&" / "'" /
// "*" / "+" /
// "-" / "/" /
// "=" / "?" /
// "^" / "_" /
// "`" / "{" /
// "|" / "}" /
// "~"
// But RFC 5321 only allows letter-digit-hyphen to comply with DNS rules (RFCs 1034 & 1123)
// http://tools.ietf.org/html/rfc5321#section-4.1.2
// sub-domain = Let-dig [Ldh-str]
//
// Let-dig = ALPHA / DIGIT
//
// Ldh-str = *( ALPHA / DIGIT / "-" ) Let-dig
//
if ($end_or_die) {
// We have encountered atext where it is no longer valid
switch ($context_prior) {
case ISEMAIL_CONTEXT_COMMENT:
case ISEMAIL_CONTEXT_FWS:
$return_status[] = ISEMAIL_ERR_ATEXT_AFTER_CFWS;
break;
case ISEMAIL_COMPONENT_LITERAL:
$return_status[] = ISEMAIL_ERR_ATEXT_AFTER_DOMLIT;
break;
default:
die ("More atext found where none is allowed, but unrecognised prior context: $context_prior");
}
}
$ord = ord($token);
$hyphen_flag = false; // Assume this token isn't a hyphen unless we discover it is
if (($ord < 33) || ($ord > 126) || (!is_bool(strpos(ISEMAIL_STRING_SPECIALS, $token)))) {
$return_status[] = ISEMAIL_ERR_EXPECTING_ATEXT; // Fatal error
} elseif ($token === ISEMAIL_STRING_HYPHEN) {
if ($element_len === 0) {
// Hyphens can't be at the beginning of a subdomain
$return_status[] = ISEMAIL_ERR_DOMAINHYPHENSTART; // Fatal error
}
$hyphen_flag = true;
} elseif (!(($ord > 47 && $ord < 58) || ($ord > 64 && $ord < 91) || ($ord > 96 && $ord < 123))) {
// Not an RFC 5321 subdomain, but still OK by RFC 5322
$return_status[] = ISEMAIL_RFC5322_DOMAIN;
}
$parsedata[ISEMAIL_COMPONENT_DOMAIN] .= $token;
$atomlist[ISEMAIL_COMPONENT_DOMAIN][$element_count] .= $token;
$element_len++;
}
break;
//-------------------------------------------------------------
// Domain literal
//-------------------------------------------------------------
case ISEMAIL_COMPONENT_LITERAL:
// http://tools.ietf.org/html/rfc5322#section-3.4.1
// domain-literal = [CFWS] "[" *([FWS] dtext) [FWS] "]" [CFWS]
//
// dtext = %d33-90 / ; Printable US-ASCII
// %d94-126 / ; characters not including
// obs-dtext ; "[", "]", or "\"
//
// obs-dtext = obs-NO-WS-CTL / quoted-pair
switch ($token) {
// End of domain literal
case ISEMAIL_STRING_CLOSESQBRACKET:
if ((int) max($return_status) < ISEMAIL_DEPREC) {
// Could be a valid RFC 5321 address literal, so let's check
// http://tools.ietf.org/html/rfc5321#section-4.1.2
// address-literal = "[" ( IPv4-address-literal /
// IPv6-address-literal /
// General-address-literal ) "]"
// ; See Section 4.1.3
//
// http://tools.ietf.org/html/rfc5321#section-4.1.3
// IPv4-address-literal = Snum 3("." Snum)
//
// IPv6-address-literal = "IPv6:" IPv6-addr
//
// General-address-literal = Standardized-tag ":" 1*dcontent
//
// Standardized-tag = Ldh-str
// ; Standardized-tag MUST be specified in a
// ; Standards-Track RFC and registered with IANA
//
// dcontent = %d33-90 / ; Printable US-ASCII
// %d94-126 ; excl. "[", "\", "]"
//
// Snum = 1*3DIGIT
// ; representing a decimal integer
// ; value in the range 0 through 255
//
// IPv6-addr = IPv6-full / IPv6-comp / IPv6v4-full / IPv6v4-comp
//
// IPv6-hex = 1*4HEXDIG
//
// IPv6-full = IPv6-hex 7(":" IPv6-hex)
//
// IPv6-comp = [IPv6-hex *5(":" IPv6-hex)] "::"
// [IPv6-hex *5(":" IPv6-hex)]
// ; The "::" represents at least 2 16-bit groups of
// ; zeros. No more than 6 groups in addition to the
// ; "::" may be present.
//
// IPv6v4-full = IPv6-hex 5(":" IPv6-hex) ":" IPv4-address-literal
//
// IPv6v4-comp = [IPv6-hex *3(":" IPv6-hex)] "::"
// [IPv6-hex *3(":" IPv6-hex) ":"]
// IPv4-address-literal
// ; The "::" represents at least 2 16-bit groups of
// ; zeros. No more than 4 groups in addition to the
// ; "::" and IPv4-address-literal may be present.
//
// is_email() author's note: We can't use ip2long() to validate
// IPv4 addresses because it accepts abbreviated addresses
// (xxx.xxx.xxx), expanding the last group to complete the address.
// filter_var() validates IPv6 address inconsistently (up to PHP 5.3.3
// at least) -- see http://bugs.php.net/bug.php?id=53236 for example
$max_groups = 8;
$matchesIP = array();
/*.mixed.*/ $index = false;
$addressliteral = $parsedata[ISEMAIL_COMPONENT_LITERAL];
// Extract IPv4 part from the end of the address-literal (if there is one)
if (preg_match('/\\b(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)$/', $addressliteral, $matchesIP) > 0) {
$index = strrpos($addressliteral, $matchesIP[0]);
if ($index !== 0) $addressliteral = substr($addressliteral, 0, $index) . '0:0'; // Convert IPv4 part to IPv6 format for further testing
}
if ($index === 0) {
// Nothing there except a valid IPv4 address, so...
$return_status[] = ISEMAIL_RFC5321_ADDRESSLITERAL;
} elseif (strncasecmp($addressliteral, ISEMAIL_STRING_IPV6TAG, 5) !== 0) {
$return_status[] = ISEMAIL_RFC5322_DOMAINLITERAL;
} else {
$IPv6 = substr($addressliteral, 5);
$matchesIP = explode(ISEMAIL_STRING_COLON, $IPv6); // Revision 2.7: Daniel Marschall's new IPv6 testing strategy
$groupCount = count($matchesIP);
$index = strpos($IPv6,ISEMAIL_STRING_DOUBLECOLON);
if ($index === false) {
// We need exactly the right number of groups
if ($groupCount !== $max_groups)
$return_status[] = ISEMAIL_RFC5322_IPV6_GRPCOUNT;
} else {
if ($index !== strrpos($IPv6,ISEMAIL_STRING_DOUBLECOLON))
$return_status[] = ISEMAIL_RFC5322_IPV6_2X2XCOLON;
else {
if ($index === 0 || $index === (strlen($IPv6) - 2)) $max_groups++; // RFC 4291 allows :: at the start or end of an address with 7 other groups in addition
if ($groupCount > $max_groups)
$return_status[] = ISEMAIL_RFC5322_IPV6_MAXGRPS;
elseif ($groupCount === $max_groups)
$return_status[] = ISEMAIL_RFC5321_IPV6DEPRECATED; // Eliding a single "::"
}
}
// Revision 2.7: Daniel Marschall's new IPv6 testing strategy
if ((substr($IPv6, 0, 1) === ISEMAIL_STRING_COLON) && (substr($IPv6, 1, 1) !== ISEMAIL_STRING_COLON))
$return_status[] = ISEMAIL_RFC5322_IPV6_COLONSTRT; // Address starts with a single colon
elseif ((substr($IPv6, -1) === ISEMAIL_STRING_COLON) && (substr($IPv6, -2, 1) !== ISEMAIL_STRING_COLON))
$return_status[] = ISEMAIL_RFC5322_IPV6_COLONEND; // Address ends with a single colon
elseif (count(preg_grep('/^[0-9A-Fa-f]{0,4}$/', $matchesIP, PREG_GREP_INVERT)) !== 0)
$return_status[] = ISEMAIL_RFC5322_IPV6_BADCHAR; // Check for unmatched characters
else
$return_status[] = ISEMAIL_RFC5321_ADDRESSLITERAL;
}
} else
$return_status[] = ISEMAIL_RFC5322_DOMAINLITERAL;
$parsedata[ISEMAIL_COMPONENT_DOMAIN] .= $token;
$atomlist[ISEMAIL_COMPONENT_DOMAIN][$element_count] .= $token;
$element_len++;
$context_prior = $context;
$context = (int) array_pop($context_stack);
break;
case ISEMAIL_STRING_BACKSLASH:
$return_status[] = ISEMAIL_RFC5322_DOMLIT_OBSDTEXT;
$context_stack[] = $context;
$context = ISEMAIL_CONTEXT_QUOTEDPAIR;
break;
// Folding White Space
case ISEMAIL_STRING_CR:
case ISEMAIL_STRING_SP:
case ISEMAIL_STRING_HTAB:
if (($token === ISEMAIL_STRING_CR) && ((++$i === $raw_length) || ($email[$i] !== ISEMAIL_STRING_LF))) {$return_status[] = ISEMAIL_ERR_CR_NO_LF; break;} // Fatal error
$return_status[] = ISEMAIL_CFWS_FWS;
$context_stack[] = $context;
$context = ISEMAIL_CONTEXT_FWS;
$token_prior = $token;
break;
// dtext
default:
// http://tools.ietf.org/html/rfc5322#section-3.4.1
// dtext = %d33-90 / ; Printable US-ASCII
// %d94-126 / ; characters not including
// obs-dtext ; "[", "]", or "\"
//
// obs-dtext = obs-NO-WS-CTL / quoted-pair
//
// obs-NO-WS-CTL = %d1-8 / ; US-ASCII control
// %d11 / ; characters that do not
// %d12 / ; include the carriage
// %d14-31 / ; return, line feed, and
// %d127 ; white space characters
$ord = ord($token);
// CR, LF, SP & HTAB have already been parsed above
if (($ord > 127) || ($ord === 0) || ($token === ISEMAIL_STRING_OPENSQBRACKET)) {
$return_status[] = ISEMAIL_ERR_EXPECTING_DTEXT; // Fatal error
break;
} elseif (($ord < 33) || ($ord === 127)) {
$return_status[] = ISEMAIL_RFC5322_DOMLIT_OBSDTEXT;
}
$parsedata[ISEMAIL_COMPONENT_LITERAL] .= $token;
$parsedata[ISEMAIL_COMPONENT_DOMAIN] .= $token;
$atomlist[ISEMAIL_COMPONENT_DOMAIN][$element_count] .= $token;
$element_len++;
}
break;
//-------------------------------------------------------------
// Quoted string
//-------------------------------------------------------------
case ISEMAIL_CONTEXT_QUOTEDSTRING:
// http://tools.ietf.org/html/rfc5322#section-3.2.4
// quoted-string = [CFWS]
// DQUOTE *([FWS] qcontent) [FWS] DQUOTE
// [CFWS]
//
// qcontent = qtext / quoted-pair
switch ($token) {
// Quoted pair
case ISEMAIL_STRING_BACKSLASH:
$context_stack[] = $context;
$context = ISEMAIL_CONTEXT_QUOTEDPAIR;
break;
// Folding White Space
// Inside a quoted string, spaces are allowed as regular characters.
// It's only FWS if we include HTAB or CRLF
case ISEMAIL_STRING_CR:
case ISEMAIL_STRING_HTAB:
if (($token === ISEMAIL_STRING_CR) && ((++$i === $raw_length) || ($email[$i] !== ISEMAIL_STRING_LF))) {$return_status[] = ISEMAIL_ERR_CR_NO_LF; break;} // Fatal error
// http://tools.ietf.org/html/rfc5322#section-3.2.2
// Runs of FWS, comment, or CFWS that occur between lexical tokens in a
// structured header field are semantically interpreted as a single
// space character.
// http://tools.ietf.org/html/rfc5322#section-3.2.4
// the CRLF in any FWS/CFWS that appears within the quoted-string [is]
// semantically "invisible" and therefore not part of the quoted-string
$parsedata[ISEMAIL_COMPONENT_LOCALPART] .= ISEMAIL_STRING_SP;
$atomlist[ISEMAIL_COMPONENT_LOCALPART][$element_count] .= ISEMAIL_STRING_SP;
$element_len++;
$return_status[] = ISEMAIL_CFWS_FWS;
$context_stack[] = $context;
$context = ISEMAIL_CONTEXT_FWS;
$token_prior = $token;
break;
// End of quoted string
case ISEMAIL_STRING_DQUOTE:
$parsedata[ISEMAIL_COMPONENT_LOCALPART] .= $token;
$atomlist[ISEMAIL_COMPONENT_LOCALPART][$element_count] .= $token;
$element_len++;
$context_prior = $context;
$context = (int) array_pop($context_stack);
break;
// qtext
default:
// http://tools.ietf.org/html/rfc5322#section-3.2.4
// qtext = %d33 / ; Printable US-ASCII
// %d35-91 / ; characters not including
// %d93-126 / ; "\" or the quote character
// obs-qtext
//
// obs-qtext = obs-NO-WS-CTL
//
// obs-NO-WS-CTL = %d1-8 / ; US-ASCII control
// %d11 / ; characters that do not
// %d12 / ; include the carriage
// %d14-31 / ; return, line feed, and
// %d127 ; white space characters
$ord = ord($token);
if (($ord > 127) || ($ord === 0) || ($ord === 10)) {
$return_status[] = ISEMAIL_ERR_EXPECTING_QTEXT; // Fatal error
} elseif (($ord < 32) || ($ord === 127))
$return_status[] = ISEMAIL_DEPREC_QTEXT;
$parsedata[ISEMAIL_COMPONENT_LOCALPART] .= $token;
$atomlist[ISEMAIL_COMPONENT_LOCALPART][$element_count] .= $token;
$element_len++;
}
// http://tools.ietf.org/html/rfc5322#section-3.4.1
// If the
// string can be represented as a dot-atom (that is, it contains no
// characters other than atext characters or "." surrounded by atext
// characters), then the dot-atom form SHOULD be used and the quoted-
// string form SHOULD NOT be used.
// To do
break;
//-------------------------------------------------------------
// Quoted pair
//-------------------------------------------------------------
case ISEMAIL_CONTEXT_QUOTEDPAIR:
// http://tools.ietf.org/html/rfc5322#section-3.2.1
// quoted-pair = ("\" (VCHAR / WSP)) / obs-qp
//
// VCHAR = %d33-126 ; visible (printing) characters
// WSP = SP / HTAB ; white space
//
// obs-qp = "\" (%d0 / obs-NO-WS-CTL / LF / CR)
//
// obs-NO-WS-CTL = %d1-8 / ; US-ASCII control
// %d11 / ; characters that do not
// %d12 / ; include the carriage
// %d14-31 / ; return, line feed, and
// %d127 ; white space characters
//
// i.e. obs-qp = "\" (%d0-8, %d10-31 / %d127)
$ord = ord($token);
if ($ord > 127)
$return_status[] = ISEMAIL_ERR_EXPECTING_QPAIR; // Fatal error
elseif ((($ord < 31) && ($ord !== 9)) || ($ord === 127)) // SP & HTAB are allowed
$return_status[] = ISEMAIL_DEPREC_QP;
// At this point we know where this qpair occurred so
// we could check to see if the character actually
// needed to be quoted at all.
// http://tools.ietf.org/html/rfc5321#section-4.1.2
// the sending system SHOULD transmit the
// form that uses the minimum quoting possible.
// To do: check whether the character needs to be quoted (escaped) in this context
$context_prior = $context;
$context = (int) array_pop($context_stack); // End of qpair
$token = ISEMAIL_STRING_BACKSLASH . $token;
switch ($context) {
case ISEMAIL_CONTEXT_COMMENT:
break;
case ISEMAIL_CONTEXT_QUOTEDSTRING:
$parsedata[ISEMAIL_COMPONENT_LOCALPART] .= $token;
$atomlist[ISEMAIL_COMPONENT_LOCALPART][$element_count] .= $token;
$element_len += 2; // The maximum sizes specified by RFC 5321 are octet counts, so we must include the backslash
break;
case ISEMAIL_COMPONENT_LITERAL:
$parsedata[ISEMAIL_COMPONENT_DOMAIN] .= $token;
$atomlist[ISEMAIL_COMPONENT_DOMAIN][$element_count] .= $token;
$element_len += 2; // The maximum sizes specified by RFC 5321 are octet counts, so we must include the backslash
break;
default:
die("Quoted pair logic invoked in an invalid context: $context");
}
break;
//-------------------------------------------------------------
// Comment
//-------------------------------------------------------------
case ISEMAIL_CONTEXT_COMMENT:
// http://tools.ietf.org/html/rfc5322#section-3.2.2
// comment = "(" *([FWS] ccontent) [FWS] ")"
//
// ccontent = ctext / quoted-pair / comment
switch ($token) {
// Nested comment
case ISEMAIL_STRING_OPENPARENTHESIS:
// Nested comments are OK
$context_stack[] = $context;
$context = ISEMAIL_CONTEXT_COMMENT;
break;
// End of comment
case ISEMAIL_STRING_CLOSEPARENTHESIS:
$context_prior = $context;
$context = (int) array_pop($context_stack);
// http://tools.ietf.org/html/rfc5322#section-3.2.2
// Runs of FWS, comment, or CFWS that occur between lexical tokens in a
// structured header field are semantically interpreted as a single
// space character.
//
// is_email() author's note: This *cannot* mean that we must add a
// space to the address wherever CFWS appears. This would result in
// any addr-spec that had CFWS outside a quoted string being invalid
// for RFC 5321.
// if (($context === ISEMAIL_COMPONENT_LOCALPART) || ($context === ISEMAIL_COMPONENT_DOMAIN)) {
// $parsedata[$context] .= ISEMAIL_STRING_SP;
// $atomlist[$context][$element_count] .= ISEMAIL_STRING_SP;
// $element_len++;
// }
break;
// Quoted pair
case ISEMAIL_STRING_BACKSLASH:
$context_stack[] = $context;
$context = ISEMAIL_CONTEXT_QUOTEDPAIR;
break;
// Folding White Space
case ISEMAIL_STRING_CR:
case ISEMAIL_STRING_SP:
case ISEMAIL_STRING_HTAB:
if (($token === ISEMAIL_STRING_CR) && ((++$i === $raw_length) || ($email[$i] !== ISEMAIL_STRING_LF))) {$return_status[] = ISEMAIL_ERR_CR_NO_LF; break;} // Fatal error
$return_status[] = ISEMAIL_CFWS_FWS;
$context_stack[] = $context;
$context = ISEMAIL_CONTEXT_FWS;
$token_prior = $token;
break;
// ctext
default:
// http://tools.ietf.org/html/rfc5322#section-3.2.3
// ctext = %d33-39 / ; Printable US-ASCII
// %d42-91 / ; characters not including
// %d93-126 / ; "(", ")", or "\"
// obs-ctext
//
// obs-ctext = obs-NO-WS-CTL
//
// obs-NO-WS-CTL = %d1-8 / ; US-ASCII control
// %d11 / ; characters that do not
// %d12 / ; include the carriage
// %d14-31 / ; return, line feed, and
// %d127 ; white space characters
$ord = ord($token);
if (($ord > 127) || ($ord === 0) || ($ord === 10)) {
$return_status[] = ISEMAIL_ERR_EXPECTING_CTEXT; // Fatal error
break;
} elseif (($ord < 32) || ($ord === 127)) {
$return_status[] = ISEMAIL_DEPREC_CTEXT;
}
}
break;
//-------------------------------------------------------------
// Folding White Space
//-------------------------------------------------------------
case ISEMAIL_CONTEXT_FWS:
// http://tools.ietf.org/html/rfc5322#section-3.2.2
// FWS = ([*WSP CRLF] 1*WSP) / obs-FWS
// ; Folding white space
// But note the erratum:
// http://www.rfc-editor.org/errata_search.php?rfc=5322&eid=1908:
// In the obsolete syntax, any amount of folding white space MAY be
// inserted where the obs-FWS rule is allowed. This creates the
// possibility of having two consecutive "folds" in a line, and
// therefore the possibility that a line which makes up a folded header
// field could be composed entirely of white space.
//
// obs-FWS = 1*([CRLF] WSP)
if ($token_prior === ISEMAIL_STRING_CR) {
if ($token === ISEMAIL_STRING_CR) {
$return_status[] = ISEMAIL_ERR_FWS_CRLF_X2; // Fatal error
break;
}
if (isset($crlf_count)) {
if (++$crlf_count > 1)
$return_status[] = ISEMAIL_DEPREC_FWS; // Multiple folds = obsolete FWS
} else $crlf_count = 1;
}
switch ($token) {
case ISEMAIL_STRING_CR:
if ((++$i === $raw_length) || ($email[$i] !== ISEMAIL_STRING_LF))
$return_status[] = ISEMAIL_ERR_CR_NO_LF; // Fatal error
break;
case ISEMAIL_STRING_SP:
case ISEMAIL_STRING_HTAB:
break;
default:
if ($token_prior === ISEMAIL_STRING_CR) {
$return_status[] = ISEMAIL_ERR_FWS_CRLF_END; // Fatal error
break;
}
if (isset($crlf_count)) unset($crlf_count);
$context_prior = $context;
$context = (int) array_pop($context_stack); // End of FWS
// http://tools.ietf.org/html/rfc5322#section-3.2.2
// Runs of FWS, comment, or CFWS that occur between lexical tokens in a
// structured header field are semantically interpreted as a single
// space character.
//
// is_email() author's note: This *cannot* mean that we must add a
// space to the address wherever CFWS appears. This would result in
// any addr-spec that had CFWS outside a quoted string being invalid
// for RFC 5321.
// if (($context === ISEMAIL_COMPONENT_LOCALPART) || ($context === ISEMAIL_COMPONENT_DOMAIN)) {
// $parsedata[$context] .= ISEMAIL_STRING_SP;
// $atomlist[$context][$element_count] .= ISEMAIL_STRING_SP;
// $element_len++;
// }
$i--; // Look at this token again in the parent context
}
$token_prior = $token;
break;
//-------------------------------------------------------------
// A context we aren't expecting
//-------------------------------------------------------------
default:
die("Unknown context: $context");
}
//-echo "<td>$context|",(($end_or_die) ? 'true' : 'false'),"|$token|" . max($return_status) . "</td></tr>"; // debug
if ((int) max($return_status) > ISEMAIL_RFC5322) break; // No point going on if we've got a fatal error
}
// Some simple final tests
if ((int) max($return_status) < ISEMAIL_RFC5322) {
if ($context === ISEMAIL_CONTEXT_QUOTEDSTRING) $return_status[] = ISEMAIL_ERR_UNCLOSEDQUOTEDSTR; // Fatal error
elseif ($context === ISEMAIL_CONTEXT_QUOTEDPAIR) $return_status[] = ISEMAIL_ERR_BACKSLASHEND; // Fatal error
elseif ($context === ISEMAIL_CONTEXT_COMMENT) $return_status[] = ISEMAIL_ERR_UNCLOSEDCOMMENT; // Fatal error
elseif ($context === ISEMAIL_COMPONENT_LITERAL) $return_status[] = ISEMAIL_ERR_UNCLOSEDDOMLIT; // Fatal error
elseif ($token === ISEMAIL_STRING_CR) $return_status[] = ISEMAIL_ERR_FWS_CRLF_END; // Fatal error
elseif ($parsedata[ISEMAIL_COMPONENT_DOMAIN] === '') $return_status[] = ISEMAIL_ERR_NODOMAIN; // Fatal error
elseif ($element_len === 0) $return_status[] = ISEMAIL_ERR_DOT_END; // Fatal error
elseif ($hyphen_flag) $return_status[] = ISEMAIL_ERR_DOMAINHYPHENEND; // Fatal error
// http://tools.ietf.org/html/rfc5321#section-4.5.3.1.2
// The maximum total length of a domain name or number is 255 octets.
elseif (strlen($parsedata[ISEMAIL_COMPONENT_DOMAIN]) > 255)
$return_status[] = ISEMAIL_RFC5322_DOMAIN_TOOLONG;
// http://tools.ietf.org/html/rfc5321#section-4.1.2
// Forward-path = Path
//
// Path = "<" [ A-d-l ":" ] Mailbox ">"
//
// http://tools.ietf.org/html/rfc5321#section-4.5.3.1.3
// The maximum total length of a reverse-path or forward-path is 256
// octets (including the punctuation and element separators).
//
// Thus, even without (obsolete) routing information, the Mailbox can
// only be 254 characters long. This is confirmed by this verified
// erratum to RFC 3696:
//
// http://www.rfc-editor.org/errata_search.php?rfc=3696&eid=1690
// However, there is a restriction in RFC 2821 on the length of an
// address in MAIL and RCPT commands of 254 characters. Since addresses
// that do not fit in those fields are not normally useful, the upper
// limit on address lengths should normally be considered to be 254.
elseif (strlen($parsedata[ISEMAIL_COMPONENT_LOCALPART] . ISEMAIL_STRING_AT . $parsedata[ISEMAIL_COMPONENT_DOMAIN]) > 254)
$return_status[] = ISEMAIL_RFC5322_TOOLONG;
// http://tools.ietf.org/html/rfc1035#section-2.3.4
// labels 63 octets or less
elseif ($element_len > 63) $return_status[] = ISEMAIL_RFC5322_LABEL_TOOLONG;
}
// Check DNS?
$dns_checked = false;
if ($checkDNS && ((int) max($return_status) < ISEMAIL_DNSWARN) && function_exists('dns_get_record')) {
// http://tools.ietf.org/html/rfc5321#section-2.3.5
// Names that can
// be resolved to MX RRs or address (i.e., A or AAAA) RRs (as discussed
// in Section 5) are permitted, as are CNAME RRs whose targets can be
// resolved, in turn, to MX or address RRs.
//
// http://tools.ietf.org/html/rfc5321#section-5.1
// The lookup first attempts to locate an MX record associated with the
// name. If a CNAME record is found, the resulting name is processed as
// if it were the initial name. ... If an empty list of MXs is returned,
// the address is treated as if it was associated with an implicit MX
// RR, with a preference of 0, pointing to that host.
//
// is_email() author's note: We will regard the existence of a CNAME to be
// sufficient evidence of the domain's existence. For performance reasons
// we will not repeat the DNS lookup for the CNAME's target, but we will
// raise a warning because we didn't immediately find an MX record.
if ($element_count === 0) $parsedata[ISEMAIL_COMPONENT_DOMAIN] .= '.'; // Checking TLD DNS seems to work only if you explicitly check from the root
$result = @dns_get_record($parsedata[ISEMAIL_COMPONENT_DOMAIN], DNS_MX); // Not using checkdnsrr because of a suspected bug in PHP 5.3 (http://bugs.php.net/bug.php?id=51844)
if ((is_bool($result) && !(bool) $result))
$return_status[] = ISEMAIL_DNSWARN_NO_RECORD; // Domain can't be found in DNS
else {
if (count($result) === 0) {
$return_status[] = ISEMAIL_DNSWARN_NO_MX_RECORD; // MX-record for domain can't be found
$result = @dns_get_record($parsedata[ISEMAIL_COMPONENT_DOMAIN], DNS_A + DNS_CNAME);
if (count($result) === 0)
$return_status[] = ISEMAIL_DNSWARN_NO_RECORD; // No usable records for the domain can be found
} else $dns_checked = true;
}
}
// Check for TLD addresses
// -----------------------
// TLD addresses are specifically allowed in RFC 5321 but they are
// unusual to say the least. We will allocate a separate
// status to these addresses on the basis that they are more likely
// to be typos than genuine addresses (unless we've already
// established that the domain does have an MX record)
//
// http://tools.ietf.org/html/rfc5321#section-2.3.5
// In the case
// of a top-level domain used by itself in an email address, a single
// string is used without any dots. This makes the requirement,
// described in more detail below, that only fully-qualified domain
// names appear in SMTP transactions on the public Internet,
// particularly important where top-level domains are involved.
//
// TLD format
// ----------
// The format of TLDs has changed a number of times. The standards
// used by IANA have been largely ignored by ICANN, leading to
// confusion over the standards being followed. These are not defined
// anywhere, except as a general component of a DNS host name (a label).
// However, this could potentially lead to 123.123.123.123 being a
// valid DNS name (rather than an IP address) and thereby creating
// an ambiguity. The most authoritative statement on TLD formats that
// the author can find is in a (rejected!) erratum to RFC 1123
// submitted by John Klensin, the author of RFC 5321:
//
// http://www.rfc-editor.org/errata_search.php?rfc=1123&eid=1353
// However, a valid host name can never have the dotted-decimal
// form #.#.#.#, since this change does not permit the highest-level
// component label to start with a digit even if it is not all-numeric.
if (!$dns_checked && ((int) max($return_status) < ISEMAIL_DNSWARN)) {
if ($element_count === 0) $return_status[] = ISEMAIL_RFC5321_TLD;
if (is_numeric($atomlist[ISEMAIL_COMPONENT_DOMAIN][$element_count][0]))
$return_status[] = ISEMAIL_RFC5321_TLDNUMERIC;
}
$return_status = array_unique($return_status);
$final_status = (int) max($return_status);
if (count($return_status) !== 1) array_shift($return_status); // remove redundant ISEMAIL_VALID
$parsedata['status'] = $return_status;
if ($final_status < $threshold) $final_status = ISEMAIL_VALID;
return ($diagnose) ? $final_status : ($final_status < ISEMAIL_THRESHOLD);
}
}
?>