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Php implements RFC-compatible email address verification

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Php implements RFC-compatible email address verification

  3. /*

  4. Copyright 2009 Dominic Sayers
  5. Dominic_sayers@hotmail.com)
  6. Http://www.dominicsayers.com)

  7. This source file is subject to the Common Public Attribution License Version 1.0 (CPAL) license.

  8. The license terms are available through the world-wide-web at http://www.opensource.org/licenses/cpal_1.0
  9. */
  10. Function is_email ($ email, $ checkDNS = false ){
  11. // Check that $ email is a valid address
  12. // (Http://tools.ietf.org/html/rfc3696)
  13. // (Http://tools.ietf.org/html/rfc5322#section-3.4.1)
  14. // (Http://tools.ietf.org/html/rfc5321#section-4.1.3)
  15. // (Http://tools.ietf.org/html/rfc4291#section-2.2)
  16. // (Http://tools.ietf.org/html/rfc1123#section-2.1)
  18. // Contemporary email addresses consist of a "local part" separated from
  19. // A "domain part" (a fully-qualified domain name) by an at-sign ("@").
  20. // (Http://tools.ietf.org/html/rfc3696#section-3)
  21. $ Index = strrpos ($ email ,'@');

  22. If ($ index = false) return false; // No at-sign

  23. If ($ index = 0) return false; // No local part
  24. If ($ index> 64) return false; // Local part too long

  25. $ LocalPart = substr ($ email, 0, $ index );

  26. $ Domain = substr ($ email, $ index + 1 );
  27. $ DomainLength = strlen ($ domain );
  29. If ($ domainLength = 0) return false; // No domain part
  30. If ($ domainLength> 255) return false; // Domain part too long

  31. // Let's check the local part for RFC compliance...

  32. //
  33. // Period (".") may... appear, but may not be used to start or end
  34. // Local part, nor may two or more consecutive periods appear.
  35. // (Http://tools.ietf.org/html/rfc3696#section-3)
  36. If (preg_match ('/^ \. | \. \. | \. $/', $ localPart)> 0) return false; // Dots in wrong place

  37. // Any ASCII graphic (printing) character other than

  38. // At-sign ("@"), backslash, double quote, comma, or square brackets may
  39. // Appear without quoting. If any of that list of excluded characters
  40. // Are to appear, they must be quoted
  41. // (Http://tools.ietf.org/html/rfc3696#section-3)
  42. If (preg_match ('/^ "(? :.) * "$/', $ LocalPart)> 0 ){
  43. // Local part is a quoted string
  44. If (preg_match ('/(? :.) + [^ \] "(? :.) +/', $ LocalPart)> 0) return false; // Unescaped quote character inside quoted string
  45. } Else {
  46. If (preg_match ('/[@ \ [\] \ ",]/', $ localPart)> 0)
  47. // Check all excluded characters are escaped
  48. $ Stripped = preg_replace ('/\\\ [\ [\\] \\\ ",]/','', $ localPart );
  49. If (preg_match ('/[@ \ [\] \ ",]/', $ stripped)> 0) return false; // Unquoted excluded characters
  50. }

  51. // Now let's check the domain part...

  52. // The domain name can also be replaced by an IP address in square brackets

  53. // (Http://tools.ietf.org/html/rfc3696#section-3)
  54. // (Http://tools.ietf.org/html/rfc5321#section-4.1.3)
  55. // (Http://tools.ietf.org/html/rfc4291#section-2.2)
  56. If (preg_match ('/^ \ [(.) +] $/', $ domain) === 1 ){
  57. // It's an address-literal
  58. $ AddressLiteral = substr ($ domain, 1, $ domainLength-2 );
  59. $ MatchesIP = array ();
  61. // Extract IPv4 part from the end of the address-literal (if there is one)
  62. 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 ){
  63. $ Index = strrpos ($ addressLiteral, $ matchesIP [0]);
  65. If ($ index = 0 ){
  66. // Nothing there handle T a valid IPv4 address, so...
  67. Return true;
  68. } Else {
  69. // Assume it's an attempt at a mixed address (IPv6 + IPv4)
  70. If ($ addressLiteral [$ index-1]! = ':') Return false; // Character preceding IPv4 address must be ':'
  71. If (substr ($ addressLiteral, 0, 5 )! = 'Ipv6: ') return false; // RFC5321 section 4.1.3

  72. $ IPv6 = substr ($ addressLiteral, 5, ($ index = 7 )? 2: $ index-6 );

  73. $ GroupMax = 6;
  74. }
  75. } Else {
  76. // It must be an attempt at pure IPv6
  77. If (substr ($ addressLiteral, 0, 5 )! = 'Ipv6: ') return false; // RFC5321 section 4.1.3
  78. $ IPv6 = substr ($ addressLiteral, 5 );
  79. $ GroupMax = 8;
  80. }

  81. $ GroupCount = preg_match_all ('/^ [0-9a-fA-F] {} |\\: [0-9a-fA-F] {} | (.)/', $ IPv6, $ matchesIP );

  82. $ Index = strpos ($ IPv6 ,'::');

  83. If ($ index = false ){

  84. // We need exactly the right number of groups
  85. If ($ groupCount! ==$ GroupMax) return false; // RFC5321 section 4.1.3
  86. } Else {
  87. If ($ index! = Strrpos ($ IPv6, ':') return false; // More than one '::'
  88. $ GroupMax = ($ index = 0 | $ index = (strlen ($ IPv6)-2 ))? $ GroupMax: $ groupMax-1;
  89. If ($ groupCount> $ groupMax) return false; // Too quota IPv6 groups in address
  90. }

  91. // Check for unmatched characters

  92. Array_multisort ($ matchesIP [1], SORT_DESC );
  93. If ($ matchesIP [1] [0]! = '') Return false; // Illegal characters in address

  94. // It's a valid IPv6 address, so...

  95. Return true;
  96. } Else {
  97. // It's a domain name...

  98. // The syntax of a legal Internet host name was specified in RFC-952

  99. // One aspect of host name syntax is hereby changed:
  100. // Restriction on the first character is relaxed to allow either
  101. // Letter or a digit.
  102. // (Http://tools.ietf.org/html/rfc1123#section-2.1)
  103. //
  104. // Nb rfc 1123 updates RFC 1035, but this is not currently apparent from reading RFC 1035.
  105. //
  106. // Most common applications, including email and the Web, will generally not permit... escaped strings
  107. // (Http://tools.ietf.org/html/rfc3696#section-2)
  108. //
  109. // Characters outside the set of alphabetic characters, digits, and hyphen must not appear in domain name
  110. // Labels for SMTP clients or servers
  111. // (Http://tools.ietf.org/html/rfc5321#section-4.1.2)
  112. //
  113. // RFC5321 precludes the use of a trailing dot in a domain name for SMTP purposes
  114. // (Http://tools.ietf.org/html/rfc5321#section-4.1.2)
  115. $ Matches = array ();
  116. $ GroupCount = preg_match_all ('/(? : [0-9a-zA-Z] [0-9a-zA-Z-] {0, 61} [0-9a-zA-Z] | [a-zA-Z]) (? : \. | $) | (.)/', $ Domain, $ matches );
  117. $ Level = count ($ matches [0]);

  118. If ($ level = 1) return false; // Mail host can't be a TLD

  119. $ TLD = $ matches [0] [$ level-1];

  120. If (substr ($ TLD, strlen ($ TLD)-1, 1) ==='. ') return false; // TLD can't end in a dot
  121. If (preg_match ('/^ [0-9] + $/', $ TLD)> 0) return false; // TLD can't be all-numeric

  122. // Check for unmatched characters

  123. Array_multisort ($ matches [1], SORT_DESC );
  124. If ($ matches [1] [0]! = '') Return false; // Illegal characters in domain, or label longer than 63 characters

  125. // Check DNS?

  126. If ($ checkDNS & function_exists ('checkdnsrr ')){
  127. If (! (Checkdnsrr ($ domain, 'A') | checkdnsrr ($ domain, 'MX '))){
  128. Return false; // Domain doesn' t actually exist
  129. }
  130. }

  131. // Eliminate all other factors, and the one which remains must be the truth.

  132. // (Sherlock Holmes, The Sign of Four)
  133. Return true;
  134. }
  135. }

  136. Function unitTest ($ email, $ reason = ''){

  137. $ Expected = ($ reason = '')? True: false;
  138. $ Valid = is_email ($ email );
  139. $ Not = ($ valid )? '': 'Not ';
  140. $ Unexpected = ($ valid! ==$ Expected )? 'This was unexpected!':'';
  141. $ Reason = ($ reason = '')? "": "Reason: $ reason ";
  143. Return "The address$ EmailIs $ not valid. $ unexpected $ reason
    \ N ";
  144. }

  145. // Email validator test cases (Dominic Sayers, January 2009)

  146. // Valid addresses
  147. Echo unitTest ('First. last@example.com ');
  148. Echo unitTest ('1970 @ example.com ');
  149. Echo unitTest ('"first last" @ example.com ');
  150. Echo unitTest ('"first \" last "@ example.com'); // Not totally sure whether this is valid or not
  151. Echo unitTest ('First \ @ last@example.com ');
  152. Echo unitTest ('"first @ last" @ example.com ');
  153. Echo unitTest ('First \ last@example.com '); // Note that \ is escaped even in single-quote strings, so this is testing "first \ last" @ example.com
  154. Echo unitTest ('first. last@x23456789.x23456789.x23456789.x23456789.x23456789.x23456789.x23456789.x23456789.x23456789.x23456789.x23456789.x23456789.x23456789.x23456789.
  155. Examples. x23456789.x23456789. x23456789.x23456789. x23456789.x23456789. x23456789.x23456789. x23456789.x2345 ');
  156. Echo unitTest ('First. last @ [12.34.56.78] ');
  157. Echo unitTest ('First. last @ [IPv6: 12.34.56.78] ');
  158. Echo unitTest ('First. last @ [IPv6: 1111: 2222: 3333: 12.34.56.78] ');
  159. Echo unitTest ('First. last @ [IPv6: 1111: 2222: 3333: 4444: 5555: 6666: 12.34.56.78] ');
  160. Echo unitTest ('First. last @ [IPv6: 1111: 2222: 3333: 4444: 5555: 6666] ');
  161. Echo unitTest ('First. last @ [IPv6: 1111: 2222: 3333: 4444: 5555] ');
  162. Echo unitTest ('First. last @ [IPv6: 1111: 2222: 3333: 4444: 5555: 6666:] ');
  163. Echo unitTest ('First. last @ [IPv6: 1111: 2222: 3333: 4444: 5555: 6666: 7777: 8888] ');
  164. Echo unitTest ('First. last@x23456789012345678901234567890123456789012345678901234567890123.example.com ');
  165. Echo unitTest ('First. last@1xample.com ');
  166. Echo unitTest ('First. last@123.example.com ');

  167. // Invalid addresses

  168. Echo unitTest ('First. la', "No @");
  169. Echo unitTest ('@ example.com', "No local part ");
  170. Echo unitTest ('1970 @ example.com ', "Local part more than 64 characters ");
  171. Echo unitTest ('. first.last@example.com', "Local part starts with a dot ");
  172. Echo unitTest ('First. last.@example.com ', "Local part ends with a dot ");
  173. Echo unitTest ('First .. ts ', "Local part has consecutive dots ");
  174. Echo unitTest ('"first" last "@ example.com'," Local part contains unescaped excluded characters ");
  175. Echo unitTest ('First \\\@ last@example.com ', "Local part contains unescaped excluded characters ");
  176. Echo unitTest ('First. last @ ', "No domain ");
  177. Echo unitTest ('first. last@x23456789.x23456789.x23456789.x23456789.x23456789.x23456789.x23456789.x23456789.x23456789.x23456789.x23456789.x23456789.x23456789.x23456789.
  178. Examples. Examples. x23456789.x23456789. x23456789.x23456789. x23456789.x23456789. x23456789.x23456', "Domain exceeds 255 chars ");
  179. Echo unitTest ('First. last @ [. 12.34.56.78] ', "Only char that can precede IPv4 address is ':'");
  180. Echo unitTest ('First. last @ [12.34.56.789] ', "Can't be interpreted as IPv4 so IPv6 tag is missing ");
  181. Echo unitTest ('First. last @ [: 12.34.56.78] ', "IPv6 tag is missing ");
  182. Echo unitTest ('First. last @ [Protocol 5: 12.34.56.78] ', "IPv6 tag is wrong ");
  183. Echo unitTest ('First. last @ [IPv6: 1111: 2222: 3333: 4444: 5555: 12.34.56.78] ', "Too ipvipv6 groups (4 max )");
  184. Echo unitTest ('First. last @ [IPv6: 1111: 2222: 3333: 4444: 5555: 12.34.56.78] ', "Not enough IPv6 groups ");
  185. Echo unitTest ('First. last @ [IPv6: 1111: 2222: 3333: 4444: 5555: 6666: 7777: 12.34.56.78] ', "Too ipvipv6 groups (6 max )");
  186. Echo unitTest ('First. last @ [IPv6: 1111: 2222: 3333: 4444: 5555: 6666] ', "Not enough IPv6 groups ");
  187. Echo unitTest ('First. last @ [IPv6: 1111: 2222: 3333: 4444: 5555: 6666: 7777: 8888: 9999] ', "Too ipvipv6 groups (8 max )");
  188. Echo unitTest ('First. last @ [IPv6: 1111: 2222: 3333: 4444: 5555] ', "Too comment': '(can be none or one )");
  189. Echo unitTest ('First. last @ [IPv6: 1111: 2222: 3333: 4444: 5555: 6666] ', "Too worker IPv6 groups (6 max )");
  190. Echo unitTest ('First. last @ [IPv6: 1111: 2222: 333x: 4444: 5555] ', "x is not valid in an IPv6 address ");
  191. Echo unitTest ('First. last @ [IPv6: 1111: 2222: 33333: 4444: 5555] ', "33333 is not a valid group in an IPv6 address ");
  192. Echo unitTest ('First. last@example.123 ', "TLD can't be all digits ");
  193. Echo unitTest ('First. last @ com ', "Mail host must be second-or lower level ");
  194. Echo unitTest ('First. last@-xample.com ', "Label can't begin with a hyphen ");
  195. Echo unitTest ('First. last@exampl-.com ', "Label can't end with a hyphen ");
  196. Echo unitTest ('First. last@x234567890123456789012345678901234567890123456789012345678901234.example.com ', "Label can't be longer than 63 ETS ");

  197. // Test cases from rfc00006 (February 2004, http://tools.ietf.org/html/rfc3696#section-3)

  198. Echo unitTest ('ABC \ @ def@example.com ');
  199. Echo unitTest ('Fred \ Bloggs@example.com ');
  200. Echo unitTest ('Joe. \\\ Blow@example.com ');
  201. Echo unitTest ('"Abc @ def" @ example.com ');
  202. Echo unitTest ('"Fred Bloggs" @ example.com ');
  203. Echo unitTest ('User + mailbox@example.com ');
  204. Echo unitTest ('customer/department = shipping@example.com ');
  205. Echo unitTest ('$ A12345@example.com ');
  206. Echo unitTest ('! Def! Xyz % abc@example.com ');
  207. Echo unitTest ('_ somename@example.com ');

  208. // Test cases from Doug Lovell (LinuxJournal, June 2007, http://www.linuxjournal.com/article/9585)

  209. Echo unitTest ("dclo@us.ibm.com ");
  210. Echo unitTest ("abc \ @ def@example.com ");
  211. Echo unitTest ("abc \\\\@ example.com ");
  212. Echo unitTest ("Fred \ Bloggs@example.com ");
  213. Echo unitTest ("Joe. \ Blow@example.com ");
  214. Echo unitTest ("\" Abc @ def \ "@ example.com ");
  215. Echo unitTest ("\" Fred Bloggs \ "@ example.com ");
  216. Echo unitTest ("customer/department = shipping@example.com ");
  217. Echo unitTest ("\ $ A12345@example.com ");
  218. Echo unitTest ("! Def! Xyz % abc@example.com ");
  219. Echo unitTest ("_ somename@example.com ");
  220. Echo unitTest ("user + mailbox@example.com ");
  221. Echo unitTest ("peter.piper@example.com ");
  222. Echo unitTest ("Doug \" Ace \ "\ Lovell@example.com ");
  223. Echo unitTest ("\" Doug \ "Ace \" L. \ "@ example.com ");
  224. Echo unitTest ("abc @ def@example.com", "Doug Lovell says this shocould fail ");
  225. Echo unitTest ("abc \\\\@ def@example.com", "Doug Lovell says this shoshould fail ");
  226. Echo unitTest ("abc \ @ example.com", "Doug Lovell says this shoshould fail ");
  227. Echo unitTest ("@ example.com", "Doug Lovell says this showould fail ");
  228. Echo unitTest ("doug @", "Doug Lovell says this shoshould fail ");
  229. Echo unitTest ("\" qu@example.com "," Doug Lovell says this shocould fail ");
  230. Echo unitTest ("ote \" @ example.com "," Doug Lovell says this shoshould fail ");
  231. Echo unitTest (". dot@example.com", "Doug Lovell says this shocould fail ");
  232. Echo unitTest ("dot.@example.com", "Doug Lovell says this shocould fail ");
  233. Echo unitTest ("two..dot@example.com", "Doug Lovell says this shocould fail ");
  234. Echo unitTest ("\" Doug \ "Ace \" L. \ "@ example.com", "Doug Lovell says this shoshould fail ");
  235. Echo unitTest ("Doug \" Ace \ "\ L \. @ example.com", "Doug Lovell says this shoshould fail ");
  236. Echo unitTest ("hello world@example.com", "Doug Lovell says this shocould fail ");
  237. Echo unitTest ("gatsby@f. SC .ot.t.f. I .tzg.era.l.d.", "Doug Lovell says this shocould fail ");
  238. ?>

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