functions/url_parser.php

   1 <?php
   2
   3 /**
   4  * url_parser.php
   5  *
   6  * This code provides various string manipulation functions that are
   7  * used by the rest of the SquirrelMail code.
   8  *
   9  * @copyright 1999-2024 The SquirrelMail Project Team
  10  * @license http://opensource.org/licenses/gpl-license.php GNU Public License
  11  * @version $Id$
  12  * @package squirrelmail
  13  */
  14
  15 /**
  16  * Undocumented - complain, then patch.
  17  */
  18 function replaceBlock (&$in, $replace, $start, $end) {
  19     $begin = substr($in,0,$start);
  20     $end   = substr($in,$end,strlen($in)-$end);
  21     $in    = $begin.$replace.$end;
  22 }
  23
  24 /* Having this defined in just one spot could help when changes need
  25  * to be made to the pattern
  26  * Make sure that the expression is evaluated case insensitively
  27  *
  28  * RFC2822 (and RFC822) defines the left side of an email address as (roughly):
  29  *  1*atext *("." 1*atext)
  30  * where atext is: a-zA-Z0-9!#$%&'*+-/=?^_`{|}~
  31  *
  32  * Here's pretty sophisticated IP matching:
  33  * $IPMatch = '(2[0-5][0-9]|1?[0-9]{1,2})';
  34  * $IPMatch = '\[?' . $IPMatch . '(\.' . $IPMatch . '){3}\]?';
  35  */
  36 /* Here's enough: */
  37 global $IP_RegExp_Match, $Host_RegExp_Match, $Email_RegExp_Match;
  38 //FIXME: these were written for use in an ereg().... they are now being used in preg()... we need to run some tests to make sure they are fully working still
  39 $IP_RegExp_Match = '\\[?[0-9]{1,3}(\\.[0-9]{1,3}){3}\\]?';
  40 $Host_RegExp_Match = '(' . $IP_RegExp_Match .
  41     '|[0-9a-z]([-.]?[0-9a-z])*\\.[a-z][a-z]+)';
  42 // NB: the backslash in the following line escapes the forward slash, which assumes that the regular expression will be enclosed in /.../
  43 $atext = '([a-z0-9!#$&%*+\/=?^_`{|}~-]|&amp;)';
  44 $dot_atom = $atext . '+(\.' . $atext . '+)*';
  45 $Email_RegExp_Match = $dot_atom . '(%' . $Host_RegExp_Match . ')?@' .
  46                       $Host_RegExp_Match;
  47
  48 /**
  49  * Parses a body and converts all found email addresses to clickable links.
  50  *
  51  * @param string body the body to process, by ref
  52  * @return int the number of unique addresses found
  53  */
  54 function parseEmail (&$body) {
  55     global $Email_RegExp_Match;
  56     $sbody     = $body;
  57     $addresses = array();
  58
  59     /* Find all the email addresses in the body */
  60     while (preg_match('/' . $Email_RegExp_Match . '/i', $sbody, $regs)) {
  61         $addresses[$regs[0]] = strtr($regs[0], array('&amp;' => '&'));
  62         $start = strpos($sbody, $regs[0]) + strlen($regs[0]);
  63         $sbody = substr($sbody, $start);
  64     }
  65
  66     /* Replace each email address with a compose URL */
  67     foreach ($addresses as $text => $email) {
  68         $comp_uri = makeComposeLink('src/compose.php?send_to='.urlencode($email), $text);
  69         $body = str_replace($text, $comp_uri, $body);
  70     }
  71
  72     /* Return number of unique addresses found */
  73     return count($addresses);
  74 }
  75
  76
  77 /* We don't want to re-initialize this stuff for every line.  Save work
  78  * and just do it once here.
  79  */
  80 global $url_parser_url_tokens;
  81 $url_parser_url_tokens = array(
  82     'http://',
  83     'https://',
  84     'ftp://',
  85     'telnet:',  // Special case -- doesn't need the slashes
  86     'mailto:',  // Special case -- doesn't use the slashes
  87     'gopher://',
  88     'news://');
  89
  90 global $url_parser_poss_ends;
  91 $url_parser_poss_ends = array(' ', "\n", "\r", '<', '>', ".\r", ".\n",
  92     '.&nbsp;', '&nbsp;', ')', '(', '&quot;', '&lt;', '&gt;', '.<',
  93     ']', '[', '{', '}', "\240", ', ', '. ', ",\n", ",\r");
  94
  95
  96 /**
  97  * rfc 2368 (mailto URL) preg_match() regexp
  98  * @link http://www.ietf.org/rfc/rfc2368.txt
  99  * @global string MailTo_PReg_Match the encapsulated regexp for preg_match()
 100  */
 101 global $MailTo_PReg_Match;
 102 $Mailto_Email_RegExp = '[0-9a-z%]([-_.+%]?[0-9a-z])*(%' . $Host_RegExp_Match . ')?@' . $Host_RegExp_Match;
 103 $MailTo_PReg_Match = '/((?:' . $Mailto_Email_RegExp . ')*)((?:\?(?:to|cc|bcc|subject|body)=[^\s\?&=,()]+)?(?:&amp;(?:to|cc|bcc|subject|body)=[^\s\?&=,()]+)*)/i';
 104
 105 /**
 106  * Parses a body and converts all found URLs to clickable links.
 107  *
 108  * @param string body the body to process, by ref
 109  * @return void
 110  */
 111 function parseUrl (&$body) {
 112     global $url_parser_poss_ends, $url_parser_url_tokens;
 113     $start      = 0;
 114     $blength    = strlen($body);
 115
 116     while ($start < $blength) {
 117         $target_token = '';
 118         $target_pos = $blength;
 119
 120         /* Find the first token to replace */
 121         foreach ($url_parser_url_tokens as $the_token) {
 122             $pos = strpos(strtolower($body), $the_token, $start);
 123             if (is_int($pos) && $pos < $target_pos) {
 124                 $target_pos   = $pos;
 125                 $target_token = $the_token;
 126             }
 127         }
 128
 129         /* Look for email addresses between $start and $target_pos */
 130         $check_str = substr($body, $start, $target_pos-$start);
 131
 132         if (parseEmail($check_str)) {
 133             replaceBlock($body, $check_str, $start, $target_pos);
 134             $blength    = strlen($body);
 135             $target_pos = strlen($check_str) + $start;
 136         }
 137
 138         // rfc 2368 (mailto URL)
 139         if ($target_token == 'mailto:') {
 140             $target_pos += 7;    //skip mailto:
 141             $end = $blength;
 142
 143             $mailto = substr($body, $target_pos, $end-$target_pos);
 144
 145             global $MailTo_PReg_Match;
 146             if ((preg_match($MailTo_PReg_Match, $mailto, $regs)) && ($regs[0] != '')) {
 147                 //sm_print_r($regs);
 148                 $mailto_before = $target_token . $regs[0];
 149                 /**
 150                  * '+' characters in a mailto URI don't need to be percent-encoded.
 151                  * However, when mailto URI data is transported via HTTP, '+' must
 152                  * be percent-encoded as %2B so that when the HTTP data is
 153                  * percent-decoded, you get '+' back and not a space.
 154                  */
 155                 $mailto_params = str_replace("+", "%2B", $regs[10]);
 156                 if ($regs[1]) {    //if there is an email addr before '?', we need to merge it with the params
 157                     $to = 'to=' . str_replace("+", "%2B", $regs[1]);
 158                     if (strpos($mailto_params, 'to=') > -1)    //already a 'to='
 159                         $mailto_params = str_replace('to=', $to . '%2C%20', $mailto_params);
 160                     else {
 161                         if ($mailto_params)    //already some params, append to them
 162                             $mailto_params .= '&amp;' . $to;
 163                         else
 164                             $mailto_params .= '?' . $to;
 165                     }
 166                 }
 167                 $url_str = preg_replace(array('/to=/i', '/(?<!b)cc=/i', '/bcc=/i'), array('send_to=', 'send_to_cc=', 'send_to_bcc='), $mailto_params);
 168                 $comp_uri = makeComposeLink('src/compose.php' . $url_str, $mailto_before);
 169                 replaceBlock($body, $comp_uri, $target_pos - 7, $target_pos + strlen($regs[0]));
 170                 $target_pos += strlen($comp_uri) - 7;
 171             }
 172         }
 173         else
 174         /* If there was a token to replace, replace it */
 175         if ($target_token != '') {
 176             /* Find the end of the URL */
 177             $end = $blength;
 178             foreach ($url_parser_poss_ends as $val) {
 179                 $enda = strpos($body, $val, $target_pos);
 180                 if (is_int($enda) && $enda < $end) {
 181                     $end = $enda;
 182                 }
 183             }
 184
 185             /* make sure that there are no 8bit chars between $target_pos and suspected end of URL */
 186             if (!is_bool($first8bit=sq_strpos_8bit($body,$target_pos,$end))) {
 187                 $end = $first8bit;
 188             }
 189
 190             /* Extract URL */
 191             $url = substr($body, $target_pos, $end-$target_pos);
 192
 193             /* Needed since lines are not passed with \n or \r */
 194             while ( preg_match('/[,.]$/', $url) ) {
 195                 $url = substr( $url, 0, -1 );
 196                 $end--;
 197             }
 198
 199             /* Replace URL with HyperLinked Url, requires 1 char in link */
 200             if ($url != '' && $url != $target_token) {
 201                 $url_str = "<a href=\"$url\" target=\"_blank\">$url</a>";
 202                 replaceBlock($body,$url_str,$target_pos,$end);
 203                 $target_pos += strlen($url_str);
 204             }
 205             else {
 206                 // Not quite a valid link, skip ahead to next chance
 207                 $target_pos += strlen($target_token);
 208             }
 209         }
 210
 211         /* Move forward */
 212         $start   = $target_pos;
 213         $blength = strlen($body);
 214     }
 215 }
 216
 217 /**
 218  * Parses a string and returns the first e-mail address found.
 219  *
 220  * @param string string the string to process
 221  * @return string the first e-mail address found
 222  */
 223 function getEmail($string) {
 224     global $Email_RegExp_Match;
 225     $addresses = array();
 226
 227     /* Find all the email addresses in the body */
 228     while (preg_match('/' . $Email_RegExp_Match . '/i', $string, $regs)) {
 229         $addresses[$regs[0]] = strtr($regs[0], array('&amp;' => '&'));
 230         $start = strpos($string, $regs[0]) + strlen($regs[0]);
 231         $string = substr($string, $start);
 232     }
 233
 234     /* Return the first address, or an empty string if no address was found */
 235     $addresses = array_values($addresses);
 236     return (array_key_exists(0, $addresses) ? $addresses[0] : '');
 237 }
 238
 239 /**
 240  * Finds first occurrence of 8bit data in the string
 241  *
 242  * Function finds first 8bit symbol or html entity that represents 8bit character.
 243  * Search start is defined by $offset argument. Search ends at $maxlength position.
 244  * If $maxlength is not defined or bigger than provided string, search ends when
 245  * string ends.
 246  *
 247  * Check returned data type in order to avoid confusion between bool(false)
 248  * (not found) and int(0) (first char in the string).
 249  * @param string $haystack
 250  * @param integer $offset
 251  * @param integer $maxlength
 252  * @return mixed integer with first 8bit character position or boolean false
 253  * @since 1.5.2
 254  */
 255 function sq_strpos_8bit($haystack,$offset=0,$maxlength=false) {
 256     $ret = false;
 257
 258     if ($maxlength===false || strlen($haystack) < $maxlength) {
 259         $maxlength=strlen($haystack);
 260     }
 261
 262     for($i=$offset;$i<$maxlength;$i++) {
 263         /* rh7-8 compatibility. don't use full 8bit range in regexp */
 264         if (preg_match('/[\200-\237]|\240|[\241-\377]/',$haystack[$i])) {
 265             /* we have 8bit char. stop here and return position */
 266             $ret = $i;
 267             break;
 268         } elseif ($haystack[$i]=='&') {
 269             $substring = substr($haystack,$i);
 270             /**
 271              * 1. look for "&#(decimal number);" where decimal_number is bigger than 127
 272              * 2. look for "&x(hexadecimal number);", where hex number is bigger than x7f
 273              * 3. look for any html character entity that is not 7bit html special char. Use
 274              * own sq_get_html_translation_table() function with 'utf-8' character set in
 275              * order to get all html entities.
 276              */
 277             if ((preg_match('/^&#(\d+);/',$substring,$match) && $match[1]>127) ||
 278                 (preg_match('/^&x([0-9a-f]+);/i',$substring,$match) && $match[1]>"\x7f") ||
 279                 (preg_match('/^&([a-z]+);/i',$substring,$match) &&
 280                  !in_array($match[0],get_html_translation_table(HTML_SPECIALCHARS)) &&
 281                  in_array($match[0],sq_get_html_translation_table(HTML_ENTITIES,ENT_COMPAT,'utf-8')))) {
 282                 $ret = $i;
 283                 break;
 284             }
 285         }
 286     }
 287     return $ret;
 288 }