functions/strings.php

   1 <?php
   2
   3 /**
   4  * strings.php
   5  *
   6  * This code provides various string manipulation functions that are
   7  * used by the rest of the SquirrelMail code.
   8  *
   9  * @copyright &copy; 1999-2007 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  * Appends citation markers to the string.
  17  * Also appends a trailing space.
  18  *
  19  * @author Justus Pendleton
  20  * @param string $str The string to append to
  21  * @param int $citeLevel the number of markers to append
  22  * @return null
  23  * @since 1.5.1
  24  */
  25 function sqMakeCite (&$str, $citeLevel) {
  26     for ($i = 0; $i < $citeLevel; $i++) {
  27         $str .= '>';
  28     }
  29     if ($citeLevel != 0) {
  30         $str .= ' ';
  31     }
  32 }
  33
  34 /**
  35  * Create a newline in the string, adding citation
  36  * markers to the newline as necessary.
  37  *
  38  * @author Justus Pendleton
  39  * @param string $str the string to make a newline in
  40  * @param int $citeLevel the citation level the newline is at
  41  * @param int $column starting column of the newline
  42  * @return null
  43  * @since 1.5.1
  44  */
  45 function sqMakeNewLine (&$str, $citeLevel, &$column) {
  46     $str .= "\n";
  47     $column = 0;
  48     if ($citeLevel > 0) {
  49         sqMakeCite ($str, $citeLevel);
  50         $column = $citeLevel + 1;
  51     } else {
  52         $column = 0;
  53     }
  54 }
  55
  56 /**
  57  * Checks for spaces in strings - only used if PHP doesn't have native ctype support
  58  *
  59  * You might be able to rewrite the function by adding short evaluation form.
  60  *
  61  * possible problems:
  62  *  - iso-2022-xx charsets  - hex 20 might be part of other symbol. I might
  63  * be wrong. 0x20 is not used in iso-2022-jp. I haven't checked iso-2022-kr
  64  * and iso-2022-cn mappings.
  65  *
  66  *  - no-break space (&nbsp;) - it is 8bit symbol, that depends on charset.
  67  * there are at least three different charset groups that have nbsp in
  68  * different places.
  69  *
  70  * I don't see any charset/nbsp options in php ctype either.
  71  *
  72  * @param string $string tested string
  73  * @return bool true when only whitespace symbols are present in test string
  74  * @since 1.5.1
  75  */
  76 function sm_ctype_space($string) {
  77     if ( preg_match('/^[\x09-\x0D]|^\x20/', $string) || $string=='') {
  78         return true;
  79     } else {
  80         return false;
  81     }
  82 }
  83
  84 /**
  85  * Wraps text at $wrap characters.  While sqWordWrap takes
  86  * a single line of text and wraps it, this function works
  87  * on the entire corpus at once, this allows it to be a little
  88  * bit smarter and when and how to wrap.
  89  *
  90  * @author Justus Pendleton
  91  * @param string $body the entire body of text
  92  * @param int $wrap the maximum line length
  93  * @return string the wrapped text
  94  * @since 1.5.1
  95  */
  96 function &sqBodyWrap (&$body, $wrap) {
  97     //check for ctype support, and fake it if it doesn't exist
  98     if (!function_exists('ctype_space')) {
  99         function ctype_space ($string) {
 100             return sm_ctype_space($string);
 101         }
 102     }
 103
 104     // the newly wrapped text
 105     $outString = '';
 106     // current column since the last newline in the outstring
 107     $outStringCol = 0;
 108     $length = sq_strlen($body);
 109     // where we are in the original string
 110     $pos = 0;
 111     // the number of >>> citation markers we are currently at
 112     $citeLevel = 0;
 113
 114     // the main loop, whenever we start a newline of input text
 115     // we start from here
 116     while ($pos < $length) {
 117        // we're at the beginning of a line, get the new cite level
 118        $newCiteLevel = 0;
 119
 120        while (($pos < $length) && (sq_substr($body,$pos,1) == '>')) {
 121            $newCiteLevel++;
 122            $pos++;
 123
 124            // skip over any spaces interleaved among the cite markers
 125            while (($pos < $length) && (sq_substr($body,$pos,1) == ' ')) {
 126
 127                $pos++;
 128
 129            }
 130            if ($pos >= $length) {
 131                break;
 132            }
 133        }
 134
 135        // special case: if this is a blank line then maintain it
 136        // (i.e. try to preserve original paragraph breaks)
 137        // unless they occur at the very beginning of the text
 138        if ((sq_substr($body,$pos,1) == "\n" ) && (sq_strlen($outString) != 0)) {
 139            $outStringLast = $outString{sq_strlen($outString) - 1};
 140            if ($outStringLast != "\n") {
 141                $outString .= "\n";
 142            }
 143            sqMakeCite ($outString, $newCiteLevel);
 144            $outString .= "\n";
 145            $pos++;
 146            $outStringCol = 0;
 147            continue;
 148        }
 149
 150        // if the cite level has changed, then start a new line
 151        // with the new cite level.
 152        if (($citeLevel != $newCiteLevel) && ($pos > ($newCiteLevel + 1)) && ($outStringCol != 0)) {
 153            sqMakeNewLine ($outString, 0, $outStringCol);
 154        }
 155
 156        $citeLevel = $newCiteLevel;
 157
 158        // prepend the quote level if necessary
 159        if ($outStringCol == 0) {
 160            sqMakeCite ($outString, $citeLevel);
 161            // if we added a citation then move the column
 162            // out by citelevel + 1 (the cite markers + the space)
 163            $outStringCol = $citeLevel + ($citeLevel ? 1 : 0);
 164        } else if ($outStringCol > $citeLevel) {
 165            // not a cite and we're not at the beginning of a line
 166            // in the output.  add a space to separate the new text
 167            // from previous text.
 168            $outString .= ' ';
 169            $outStringCol++;
 170        }
 171
 172        // find the next newline -- we don't want to go further than that
 173        $nextNewline = sq_strpos ($body, "\n", $pos);
 174        if ($nextNewline === FALSE) {
 175            $nextNewline = $length;
 176        }
 177
 178        // Don't wrap unquoted lines at all.  For now the textarea
 179        // will work fine for this.  Maybe revisit this later though
 180        // (for completeness more than anything else, I think)
 181        if ($citeLevel == 0) {
 182            $outString .= sq_substr ($body, $pos, ($nextNewline - $pos));
 183            $outStringCol = $nextNewline - $pos;
 184            if ($nextNewline != $length) {
 185                sqMakeNewLine ($outString, 0, $outStringCol);
 186            }
 187            $pos = $nextNewline + 1;
 188            continue;
 189        }
 190        /**
 191         * Set this to false to stop appending short strings to previous lines
 192         */
 193        $smartwrap = true;
 194        // inner loop, (obviously) handles wrapping up to
 195        // the next newline
 196        while ($pos < $nextNewline) {
 197            // skip over initial spaces
 198            while (($pos < $nextNewline) && (ctype_space (sq_substr($body,$pos,1)))) {
 199                $pos++;
 200            }
 201            // if this is a short line then just append it and continue outer loop
 202            if (($outStringCol + $nextNewline - $pos) <= ($wrap - $citeLevel - 1) ) {
 203                // if this is the final line in the input string then include
 204                // any trailing newlines
 205                //      echo substr($body,$pos,$wrap). "<br />";
 206                if (($nextNewline + 1 == $length) && (sq_substr($body,$nextNewline,1) == "\n")) {
 207                    $nextNewline++;
 208                }
 209
 210                // trim trailing spaces
 211                $lastRealChar = $nextNewline;
 212                while (($lastRealChar > $pos && $lastRealChar < $length) && (ctype_space (sq_substr($body,$lastRealChar,1)))) {
 213                    $lastRealChar--;
 214                }
 215                // decide if appending the short string is what we want
 216                if (($nextNewline < $length && sq_substr($body,$nextNewline,1) == "\n") &&
 217                      isset($lastRealChar)) {
 218                    $mypos = $pos;
 219                    //check the first word:
 220                    while (($mypos < $length) && (sq_substr($body,$mypos,1) == '>')) {
 221                        $mypos++;
 222                        // skip over any spaces interleaved among the cite markers
 223                        while (($mypos < $length) && (sq_substr($body,$mypos,1) == ' ')) {
 224                            $mypos++;
 225                        }
 226                    }
 227 /*
 228                      $ldnspacecnt = 0;
 229                      if ($mypos == $nextNewline+1) {
 230                         while (($mypos < $length) && ($body{$mypos} == ' ')) {
 231                          $ldnspacecnt++;
 232                         }
 233                      }
 234 */
 235
 236                    $firstword = sq_substr($body,$mypos,sq_strpos($body,' ',$mypos) - $mypos);
 237                    //if ($dowrap || $ldnspacecnt > 1 || ($firstword && (
 238                    if (!$smartwrap || $firstword && (
 239                                         $firstword{0} == '-' ||
 240                                         $firstword{0} == '+' ||
 241                                         $firstword{0} == '*' ||
 242                                         sq_substr($firstword,0,1) == sq_strtoupper(sq_substr($firstword,0,1)) ||
 243                                         strpos($firstword,':'))) {
 244                         $outString .= sq_substr($body,$pos,($lastRealChar - $pos+1));
 245                         $outStringCol += ($lastRealChar - $pos);
 246                         sqMakeNewLine($outString,$citeLevel,$outStringCol);
 247                         $nextNewline++;
 248                         $pos = $nextNewline;
 249                         $outStringCol--;
 250                         continue;
 251                    }
 252
 253                }
 254
 255                $outString .= sq_substr ($body, $pos, ($lastRealChar - $pos + 1));
 256                $outStringCol += ($lastRealChar - $pos);
 257                $pos = $nextNewline + 1;
 258                continue;
 259            }
 260
 261            $eol = $pos + $wrap - $citeLevel - $outStringCol;
 262            // eol is the tentative end of line.
 263            // look backwards for there for a whitespace to break at.
 264            // if it's already less than our current position then
 265            // our current line is already too long, break immediately
 266            // and restart outer loop
 267            if ($eol <= $pos) {
 268                sqMakeNewLine ($outString, $citeLevel, $outStringCol);
 269                continue;
 270            }
 271
 272            // start looking backwards for whitespace to break at.
 273            $breakPoint = $eol;
 274            while (($breakPoint > $pos) && (! ctype_space (sq_substr($body,$breakPoint,1)))) {
 275                $breakPoint--;
 276            }
 277
 278            // if we didn't find a breakpoint by looking backward then we
 279            // need to figure out what to do about that
 280            if ($breakPoint == $pos) {
 281                // if we are not at the beginning then end this line
 282                // and start a new loop
 283                if ($outStringCol > ($citeLevel + 1)) {
 284                    sqMakeNewLine ($outString, $citeLevel, $outStringCol);
 285                    continue;
 286                } else {
 287                    // just hard break here.  most likely we are breaking
 288                    // a really long URL.  could also try searching
 289                    // forward for a break point, which is what Mozilla
 290                    // does.  don't bother for now.
 291                    $breakPoint = $eol;
 292                }
 293            }
 294
 295            // special case: maybe we should have wrapped last
 296            // time.  if the first breakpoint here makes the
 297            // current line too long and there is already text on
 298            // the current line, break and loop again if at
 299            // beginning of current line, don't force break
 300            $SLOP = 6;
 301            if ((($outStringCol + ($breakPoint - $pos)) > ($wrap + $SLOP)) && ($outStringCol > ($citeLevel + 1))) {
 302                sqMakeNewLine ($outString, $citeLevel, $outStringCol);
 303                continue;
 304            }
 305
 306            // skip newlines or whitespace at the beginning of the string
 307            $substring = sq_substr ($body, $pos, ($breakPoint - $pos));
 308            $substring = rtrim ($substring); // do rtrim and ctype_space have the same ideas about whitespace?
 309            $outString .= $substring;
 310            $outStringCol += sq_strlen ($substring);
 311            // advance past the whitespace which caused the wrap
 312            $pos = $breakPoint;
 313            while (($pos < $length) && (ctype_space (sq_substr($body,$pos,1)))) {
 314                $pos++;
 315            }
 316            if ($pos < $length) {
 317                sqMakeNewLine ($outString, $citeLevel, $outStringCol);
 318            }
 319        }
 320     }
 321
 322     return $outString;
 323 }
 324
 325 /**
 326  * Wraps text at $wrap characters
 327  *
 328  * Has a problem with special HTML characters, so call this before
 329  * you do character translation.
 330  *
 331  * Specifically, &amp;#039; comes up as 5 characters instead of 1.
 332  * This should not add newlines to the end of lines.
 333  *
 334  * @param string $line the line of text to wrap, by ref
 335  * @param int $wrap the maximum line lenth
 336  * @param string $charset name of charset used in $line string. Available since v.1.5.1.
 337  * @return void
 338  * @since 1.0
 339  */
 340 function sqWordWrap(&$line, $wrap, $charset='') {
 341     global $languages, $squirrelmail_language;
 342
 343     // Use custom wrapping function, if translation provides it
 344     if (isset($languages[$squirrelmail_language]['XTRA_CODE']) &&
 345         function_exists($languages[$squirrelmail_language]['XTRA_CODE'] . '_wordwrap')) {
 346         if (mb_detect_encoding($line) != 'ASCII') {
 347             $line = call_user_func($languages[$squirrelmail_language]['XTRA_CODE'] . '_wordwrap', $line, $wrap);
 348             return;
 349         }
 350     }
 351
 352     ereg("^([\t >]*)([^\t >].*)?$", $line, $regs);
 353     $beginning_spaces = $regs[1];
 354     if (isset($regs[2])) {
 355         $words = explode(' ', $regs[2]);
 356     } else {
 357         $words = '';
 358     }
 359
 360     $i = 0;
 361     $line = $beginning_spaces;
 362
 363     while ($i < count($words)) {
 364         /* Force one word to be on a line (minimum) */
 365         $line .= $words[$i];
 366         $line_len = strlen($beginning_spaces) + sq_strlen($words[$i],$charset) + 2;
 367         if (isset($words[$i + 1]))
 368             $line_len += sq_strlen($words[$i + 1],$charset);
 369         $i ++;
 370
 371         /* Add more words (as long as they fit) */
 372         while ($line_len < $wrap && $i < count($words)) {
 373             $line .= ' ' . $words[$i];
 374             $i++;
 375             if (isset($words[$i]))
 376                 $line_len += sq_strlen($words[$i],$charset) + 1;
 377             else
 378                 $line_len += 1;
 379         }
 380
 381         /* Skip spaces if they are the first thing on a continued line */
 382         while (!isset($words[$i]) && $i < count($words)) {
 383             $i ++;
 384         }
 385
 386         /* Go to the next line if we have more to process */
 387         if ($i < count($words)) {
 388             $line .= "\n";
 389         }
 390     }
 391 }
 392
 393 /**
 394  * Does the opposite of sqWordWrap()
 395  * @param string $body the text to un-wordwrap
 396  * @return void
 397  * @since 1.0
 398  */
 399 function sqUnWordWrap(&$body) {
 400     global $squirrelmail_language;
 401
 402     if ($squirrelmail_language == 'ja_JP') {
 403         return;
 404     }
 405
 406     $lines = explode("\n", $body);
 407     $body = '';
 408     $PreviousSpaces = '';
 409     $cnt = count($lines);
 410     for ($i = 0; $i < $cnt; $i ++) {
 411         preg_match("/^([\t >]*)([^\t >].*)?$/", $lines[$i], $regs);
 412         $CurrentSpaces = $regs[1];
 413         if (isset($regs[2])) {
 414             $CurrentRest = $regs[2];
 415         } else {
 416             $CurrentRest = '';
 417         }
 418
 419         if ($i == 0) {
 420             $PreviousSpaces = $CurrentSpaces;
 421             $body = $lines[$i];
 422         } else if (($PreviousSpaces == $CurrentSpaces) /* Do the beginnings match */
 423                    && (strlen($lines[$i - 1]) > 65)    /* Over 65 characters long */
 424                    && strlen($CurrentRest)) {          /* and there's a line to continue with */
 425             $body .= ' ' . $CurrentRest;
 426         } else {
 427             $body .= "\n" . $lines[$i];
 428             $PreviousSpaces = $CurrentSpaces;
 429         }
 430     }
 431     $body .= "\n";
 432 }
 433
 434 /**
 435  * If $haystack is a full mailbox name and $needle is the mailbox
 436  * separator character, returns the last part of the mailbox name.
 437  *
 438  * @param string haystack full mailbox name to search
 439  * @param string needle the mailbox separator character
 440  * @return string the last part of the mailbox name
 441  * @since 1.0
 442  */
 443 function readShortMailboxName($haystack, $needle) {
 444
 445     if ($needle == '') {
 446         $elem = $haystack;
 447     } else {
 448         $parts = explode($needle, $haystack);
 449         $elem = array_pop($parts);
 450         while ($elem == '' && count($parts)) {
 451             $elem = array_pop($parts);
 452         }
 453     }
 454     return( $elem );
 455 }
 456
 457
 458 /**
 459  * get_location
 460  *
 461  * Determines the location to forward to, relative to your server.
 462  * This is used in HTTP Location: redirects.
 463  *
 464  * If set, it uses $config_location_base as the first part of the URL,
 465  * specifically, the protocol, hostname and port parts. The path is
 466  * always autodetected.
 467  *
 468  * @return string the base url for this SquirrelMail installation
 469  * @since 1.0
 470  */
 471 function get_location () {
 472
 473     global $imap_server_type, $config_location_base;
 474
 475     /* Get the path, handle virtual directories */
 476     if(strpos(php_self(), '?')) {
 477         $path = substr(php_self(), 0, strpos(php_self(), '?'));
 478     } else {
 479         $path = php_self();
 480     }
 481     $path = substr($path, 0, strrpos($path, '/'));
 482
 483     // proto+host+port are already set in config:
 484     if ( !empty($config_location_base) ) {
 485         return $config_location_base . $path ;
 486     }
 487     // we computed it before, get it from the session:
 488     if ( sqgetGlobalVar('sq_base_url', $full_url, SQ_SESSION) ) {
 489       return $full_url . $path;
 490     }
 491     // else: autodetect
 492
 493     /* Check if this is a HTTPS or regular HTTP request. */
 494     $proto = 'http://';
 495
 496     /*
 497      * If you have 'SSLOptions +StdEnvVars' in your apache config
 498      *     OR if you have HTTPS=on in your HTTP_SERVER_VARS
 499      *     OR if you have HTTP_X_FORWARDED_PROTO=https in your HTTP_SERVER_VARS
 500      *     OR if you are on port 443
 501      */
 502     $getEnvVar = getenv('HTTPS');
 503     if (!sqgetGlobalVar('HTTP_X_FORWARDED_PROTO', $forwarded_proto, SQ_SERVER))
 504         $forwarded_proto = '';
 505     if ((isset($getEnvVar) && strcasecmp($getEnvVar, 'on') === 0) ||
 506         (sqgetGlobalVar('HTTPS', $https_on, SQ_SERVER) && strcasecmp($https_on, 'on') === 0) ||
 507         (strcasecmp($forwarded_proto, 'https') === 0) ||
 508         (sqgetGlobalVar('SERVER_PORT', $server_port, SQ_SERVER) &&  $server_port == 443)) {
 509         $proto = 'https://';
 510     }
 511
 512     /* Get the hostname from the Host header or server config. */
 513     if ( !sqgetGlobalVar('HTTP_X_FORWARDED_HOST', $host, SQ_SERVER) || empty($host) ) {
 514         if ( !sqgetGlobalVar('HTTP_HOST', $host, SQ_SERVER) || empty($host) ) {
 515             if ( !sqgetGlobalVar('SERVER_NAME', $host, SQ_SERVER) || empty($host) ) {
 516                 $host = '';
 517             }
 518         }
 519     }
 520
 521     $port = '';
 522     if (! strstr($host, ':')) {
 523         if (sqgetGlobalVar('SERVER_PORT', $server_port, SQ_SERVER)) {
 524             if (($server_port != 80 && $proto == 'http://') ||
 525                 ($server_port != 443 && $proto == 'https://' &&
 526                  strcasecmp($forwarded_proto, 'https') !== 0)) {
 527                 $port = sprintf(':%d', $server_port);
 528             }
 529         }
 530     }
 531
 532     /* this is a workaround for the weird macosx caching that
 533      * causes Apache to return 16080 as the port number, which causes
 534      * SM to bail */
 535
 536     if ($imap_server_type == 'macosx' && $port == ':16080') {
 537         $port = '';
 538     }
 539
 540     /* Fallback is to omit the server name and use a relative */
 541     /* URI, although this is not RFC 2616 compliant.          */
 542     $full_url = ($host ? $proto . $host . $port : '');
 543     sqsession_register($full_url, 'sq_base_url');
 544     return $full_url . $path;
 545 }
 546
 547
 548 /**
 549  * Get Message List URI
 550  *
 551  * @param string $mailbox      Current mailbox name (unencoded/raw)
 552  * @param string $startMessage The mailbox page offset
 553  * @param string $what         Any current search parameters (OPTIONAL;
 554  *                             default empty string)
 555  *
 556  * @return string The message list URI
 557  *
 558  * @since 1.5.2
 559  *
 560  */
 561 function get_message_list_uri($mailbox, $startMessage, $what='') {
 562
 563     global $base_uri;
 564
 565     $urlMailbox = urlencode($mailbox);
 566
 567     $list_xtra = "?where=read_body.php&what=$what&mailbox=" . $urlMailbox.
 568                  "&startMessage=$startMessage";
 569
 570     return $base_uri .'src/right_main.php'. $list_xtra;
 571 }
 572
 573
 574 /**
 575  * Encrypts password
 576  *
 577  * These functions are used to encrypt the password before it is
 578  * stored in a cookie. The encryption key is generated by
 579  * OneTimePadCreate();
 580  *
 581  * @param string $string the (password)string to encrypt
 582  * @param string $epad the encryption key
 583  * @return string the base64-encoded encrypted password
 584  * @since 1.0
 585  */
 586 function OneTimePadEncrypt ($string, $epad) {
 587     $pad = base64_decode($epad);
 588
 589     if (strlen($pad)>0) {
 590         // make sure that pad is longer than string
 591         while (strlen($string)>strlen($pad)) {
 592             $pad.=$pad;
 593         }
 594     } else {
 595         // FIXME: what should we do when $epad is not base64 encoded or empty.
 596     }
 597
 598     $encrypted = '';
 599     for ($i = 0; $i < strlen ($string); $i++) {
 600         $encrypted .= chr (ord($string[$i]) ^ ord($pad[$i]));
 601     }
 602
 603     return base64_encode($encrypted);
 604 }
 605
 606 /**
 607  * Decrypts a password from the cookie
 608  *
 609  * Decrypts a password from the cookie, encrypted by OneTimePadEncrypt.
 610  * This uses the encryption key that is stored in the session.
 611  *
 612  * @param string $string the string to decrypt
 613  * @param string $epad the encryption key from the session
 614  * @return string the decrypted password
 615  * @since 1.0
 616  */
 617 function OneTimePadDecrypt ($string, $epad) {
 618     $pad = base64_decode($epad);
 619
 620     if (strlen($pad)>0) {
 621         // make sure that pad is longer than string
 622         while (strlen($string)>strlen($pad)) {
 623             $pad.=$pad;
 624         }
 625     } else {
 626         // FIXME: what should we do when $epad is not base64 encoded or empty.
 627     }
 628
 629     $encrypted = base64_decode ($string);
 630     $decrypted = '';
 631     for ($i = 0; $i < strlen ($encrypted); $i++) {
 632         $decrypted .= chr (ord($encrypted[$i]) ^ ord($pad[$i]));
 633     }
 634
 635     return $decrypted;
 636 }
 637
 638
 639 /**
 640  * Randomizes the mt_rand() function.
 641  *
 642  * Toss this in strings or integers and it will seed the generator
 643  * appropriately. With strings, it is better to get them long.
 644  * Use md5() to lengthen smaller strings.
 645  *
 646  * @param mixed $val a value to seed the random number generator. mixed = integer or string.
 647  * @return void
 648  * @since 1.0
 649  */
 650 function sq_mt_seed($Val) {
 651     /* if mt_getrandmax() does not return a 2^n - 1 number,
 652        this might not work well.  This uses $Max as a bitmask. */
 653     $Max = mt_getrandmax();
 654
 655     if (! is_int($Val)) {
 656             $Val = crc32($Val);
 657     }
 658
 659     if ($Val < 0) {
 660         $Val *= -1;
 661     }
 662
 663     if ($Val == 0) {
 664         return;
 665     }
 666
 667     mt_srand(($Val ^ mt_rand(0, $Max)) & $Max);
 668 }
 669
 670
 671 /**
 672  * Init random number generator
 673  *
 674  * This function initializes the random number generator fairly well.
 675  * It also only initializes it once, so you don't accidentally get
 676  * the same 'random' numbers twice in one session.
 677  *
 678  * @return void
 679  * @since 1.0
 680  */
 681 function sq_mt_randomize() {
 682     static $randomized;
 683
 684     if ($randomized) {
 685         return;
 686     }
 687
 688     /* Global. */
 689     sqgetGlobalVar('REMOTE_PORT', $remote_port, SQ_SERVER);
 690     sqgetGlobalVar('REMOTE_ADDR', $remote_addr, SQ_SERVER);
 691     sq_mt_seed((int)((double) microtime() * 1000000));
 692     sq_mt_seed(md5($remote_port . $remote_addr . getmypid()));
 693
 694     /* getrusage */
 695     if (function_exists('getrusage')) {
 696         /* Avoid warnings with Win32 */
 697         $dat = @getrusage();
 698         if (isset($dat) && is_array($dat)) {
 699             $Str = '';
 700             foreach ($dat as $k => $v)
 701                 {
 702                     $Str .= $k . $v;
 703                 }
 704             sq_mt_seed(md5($Str));
 705         }
 706     }
 707
 708     if(sqgetGlobalVar('UNIQUE_ID', $unique_id, SQ_SERVER)) {
 709         sq_mt_seed(md5($unique_id));
 710     }
 711
 712     $randomized = 1;
 713 }
 714
 715 /**
 716  * Creates encryption key
 717  *
 718  * Creates an encryption key for encrypting the password stored in the cookie.
 719  * The encryption key itself is stored in the session.
 720  *
 721  * Pad must be longer or equal to encoded string length in 1.4.4/1.5.0 and older.
 722  * @param int $length optional, length of the string to generate
 723  * @return string the encryption key
 724  * @since 1.0
 725  */
 726 function OneTimePadCreate ($length=100) {
 727     sq_mt_randomize();
 728
 729     $pad = '';
 730     for ($i = 0; $i < $length; $i++) {
 731         $pad .= chr(mt_rand(0,255));
 732     }
 733
 734     return base64_encode($pad);
 735 }
 736
 737 /**
 738  * Returns a string showing the size of the message/attachment.
 739  *
 740  * @param int $bytes the filesize in bytes
 741  * @return string the filesize in human readable format
 742  * @since 1.0
 743  */
 744 function show_readable_size($bytes) {
 745     $bytes /= 1024;
 746     $type = 'KiB';
 747
 748     if ($bytes / 1024 > 1) {
 749         $bytes /= 1024;
 750         $type = 'MiB';
 751     }
 752
 753     if ($bytes < 10) {
 754         $bytes *= 10;
 755         settype($bytes, 'integer');
 756         $bytes /= 10;
 757     } else {
 758         settype($bytes, 'integer');
 759     }
 760
 761     return $bytes . '&nbsp;' . $type;
 762 }
 763
 764 /**
 765  * Generates a random string from the character set you pass in
 766  *
 767  * @param int $size the length of the string to generate
 768  * @param string $chars a string containing the characters to use
 769  * @param int $flags a flag to add a specific set to the characters to use:
 770  *     Flags:
 771  *       1 = add lowercase a-z to $chars
 772  *       2 = add uppercase A-Z to $chars
 773  *       4 = add numbers 0-9 to $chars
 774  * @return string the random string
 775  * @since 1.0
 776  */
 777 function GenerateRandomString($size, $chars, $flags = 0) {
 778     if ($flags & 0x1) {
 779         $chars .= 'abcdefghijklmnopqrstuvwxyz';
 780     }
 781     if ($flags & 0x2) {
 782         $chars .= 'ABCDEFGHIJKLMNOPQRSTUVWXYZ';
 783     }
 784     if ($flags & 0x4) {
 785         $chars .= '0123456789';
 786     }
 787
 788     if (($size < 1) || (strlen($chars) < 1)) {
 789         return '';
 790     }
 791
 792     sq_mt_randomize(); /* Initialize the random number generator */
 793
 794     $String = '';
 795     $j = strlen( $chars ) - 1;
 796     while (strlen($String) < $size) {
 797         $String .= $chars{mt_rand(0, $j)};
 798     }
 799
 800     return $String;
 801 }
 802
 803 /**
 804  * Escapes special characters for use in IMAP commands.
 805  *
 806  * @param string $str the string to escape
 807  * @return string the escaped string
 808  * @since 1.0.3
 809  */
 810 function quoteimap($str) {
 811     return preg_replace("/([\"\\\\])/", "\\\\$1", $str);
 812 }
 813
 814 /**
 815  * Create compose link
 816  *
 817  * Returns a link to the compose-page, taking in consideration
 818  * the compose_in_new and javascript settings.
 819  * @param string $url the URL to the compose page
 820  * @param string $text the link text, default "Compose"
 821  * @param string $target (since 1.4.3) url target
 822  * @return string a link to the compose page
 823  * @since 1.4.2
 824  */
 825 function makeComposeLink($url, $text = null, $target='') {
 826     global $compose_new_win, $compose_width,
 827            $compose_height, $oTemplate;
 828
 829     if(!$text) {
 830         $text = _("Compose");
 831     }
 832
 833     // if not using "compose in new window", make
 834     // regular link and be done with it
 835     if($compose_new_win != '1') {
 836         return makeInternalLink($url, $text, $target);
 837     }
 838
 839     // build the compose in new window link...
 840
 841
 842     // if javascript is on, use onclick event to handle it
 843     if(checkForJavascript()) {
 844         sqgetGlobalVar('base_uri', $base_uri, SQ_SESSION);
 845         $compuri = SM_BASE_URI.$url;
 846
 847         return create_hyperlink('javascript:void(0)', $text, '', "comp_in_new('$compuri','$compose_width','$compose_height')");
 848     }
 849
 850     // otherwise, just open new window using regular HTML
 851     return makeInternalLink($url, $text, '_blank');
 852 }
 853
 854 /**
 855  * version of fwrite which checks for failure
 856  * @param resource $fp
 857  * @param string $string
 858  * @return number of written bytes. false on failure
 859  * @since 1.4.3
 860  */
 861 function sq_fwrite($fp, $string) {
 862         // write to file
 863         $count = @fwrite($fp,$string);
 864         // the number of bytes written should be the length of the string
 865         if($count != strlen($string)) {
 866                 return FALSE;
 867         }
 868
 869         return $count;
 870 }
 871
 872 /**
 873  * sq_get_html_translation_table
 874  *
 875  * Returns the translation table used by sq_htmlentities()
 876  *
 877  * @param integer $table html translation table. Possible values (without quotes):
 878  *             <ul>
 879  *                <li>HTML_ENTITIES - full html entities table defined by charset</li>
 880  *                <li>HTML_SPECIALCHARS - html special characters table</li>
 881  *             </ul>
 882  * @param integer $quote_style quote encoding style. Possible values (without quotes):
 883  *              <ul>
 884  *                <li>ENT_COMPAT - (default) encode double quotes</li>
 885  *                <li>ENT_NOQUOTES -  don't encode double or single quotes</li>
 886  *                <li>ENT_QUOTES - encode double and single quotes</li>
 887  *              </ul>
 888  * @param string $charset charset used for encoding. default to us-ascii, 'auto' uses $default_charset global value.
 889  * @return array html translation array
 890  * @since 1.5.1
 891  */
 892 function sq_get_html_translation_table($table,$quote_style=ENT_COMPAT,$charset='us-ascii') {
 893   global $default_charset;
 894
 895   if ($table == HTML_SPECIALCHARS) $charset='us-ascii';
 896
 897   // Start array with ampersand
 898   $sq_html_ent_table = array( "&" => '&amp;' );
 899
 900   // < and >
 901   $sq_html_ent_table = array_merge($sq_html_ent_table,
 902                         array("<" => '&lt;',
 903                               ">" => '&gt;')
 904                         );
 905   // double quotes
 906   if ($quote_style == ENT_COMPAT)
 907      $sq_html_ent_table = array_merge($sq_html_ent_table,
 908                             array("\"" => '&quot;')
 909                             );
 910
 911   // double and single quotes
 912   if ($quote_style == ENT_QUOTES)
 913      $sq_html_ent_table = array_merge($sq_html_ent_table,
 914                             array("\"" => '&quot;',
 915                               "'" => '&#39;')
 916                             );
 917
 918   if ($charset=='auto') $charset=$default_charset;
 919
 920   // add entities that depend on charset
 921   switch($charset){
 922   case 'iso-8859-1':
 923     include_once(SM_PATH . 'functions/htmlentities/iso-8859-1.php');
 924     break;
 925   case 'utf-8':
 926     include_once(SM_PATH . 'functions/htmlentities/utf-8.php');
 927     break;
 928   case 'us-ascii':
 929   default:
 930     break;
 931   }
 932   // return table
 933   return $sq_html_ent_table;
 934 }
 935
 936 /**
 937  * sq_htmlentities
 938  *
 939  * Convert all applicable characters to HTML entities.
 940  * Minimal php requirement - v.4.0.5.
 941  *
 942  * Function is designed for people that want to use full power of htmlentities() in
 943  * i18n environment.
 944  *
 945  * @param string $string string that has to be sanitized
 946  * @param integer $quote_style quote encoding style. Possible values (without quotes):
 947  *              <ul>
 948  *                <li>ENT_COMPAT - (default) encode double quotes</li>
 949  *                <li>ENT_NOQUOTES - don't encode double or single quotes</li>
 950  *                <li>ENT_QUOTES - encode double and single quotes</li>
 951  *              </ul>
 952  * @param string $charset charset used for encoding. defaults to 'us-ascii', 'auto' uses $default_charset global value.
 953  * @return string sanitized string
 954  * @since 1.5.1
 955  */
 956 function sq_htmlentities($string,$quote_style=ENT_COMPAT,$charset='us-ascii') {
 957   // get translation table
 958   $sq_html_ent_table=sq_get_html_translation_table(HTML_ENTITIES,$quote_style,$charset);
 959   // convert characters
 960   return str_replace(array_keys($sq_html_ent_table),array_values($sq_html_ent_table),$string);
 961 }
 962
 963 /**
 964  * Tests if string contains 8bit symbols.
 965  *
 966  * If charset is not set, function defaults to default_charset.
 967  * $default_charset global must be set correctly if $charset is
 968  * not used.
 969  * @param string $string tested string
 970  * @param string $charset charset used in a string
 971  * @return bool true if 8bit symbols are detected
 972  * @since 1.5.1 and 1.4.4
 973  */
 974 function sq_is8bit($string,$charset='') {
 975     global $default_charset;
 976
 977     if ($charset=='') $charset=$default_charset;
 978
 979     /**
 980      * Don't use \240 in ranges. Sometimes RH 7.2 doesn't like it.
 981      * Don't use \200-\237 for iso-8859-x charsets. This range
 982      * stores control symbols in those charsets.
 983      * Use preg_match instead of ereg in order to avoid problems
 984      * with mbstring overloading
 985      */
 986     if (preg_match("/^iso-8859/i",$charset)) {
 987         $needle='/\240|[\241-\377]/';
 988     } else {
 989         $needle='/[\200-\237]|\240|[\241-\377]/';
 990     }
 991     return preg_match("$needle",$string);
 992 }
 993
 994 /**
 995  * Replacement of mb_list_encodings function
 996  *
 997  * This function provides replacement for function that is available only
 998  * in php 5.x. Function does not test all mbstring encodings. Only the ones
 999  * that might be used in SM translations.
1000  *
1001  * Supported strings are stored in session in order to reduce number of
1002  * mb_internal_encoding function calls.
1003  *
1004  * If you want to test all mbstring encodings - fill $list_of_encodings
1005  * array.
1006  * @return array list of encodings supported by php mbstring extension
1007  * @since 1.5.1 and 1.4.6
1008  */
1009 function sq_mb_list_encodings() {
1010     if (! function_exists('mb_internal_encoding'))
1011         return array();
1012
1013     // php 5+ function
1014     if (function_exists('mb_list_encodings')) {
1015         $ret = mb_list_encodings();
1016         array_walk($ret,'sq_lowercase_array_vals');
1017         return $ret;
1018     }
1019
1020     // don't try to test encodings, if they are already stored in session
1021     if (sqgetGlobalVar('mb_supported_encodings',$mb_supported_encodings,SQ_SESSION))
1022         return $mb_supported_encodings;
1023
1024     // save original encoding
1025     $orig_encoding=mb_internal_encoding();
1026
1027     $list_of_encoding=array(
1028         'pass',
1029         'auto',
1030         'ascii',
1031         'jis',
1032         'utf-8',
1033         'sjis',
1034         'euc-jp',
1035         'iso-8859-1',
1036         'iso-8859-2',
1037         'iso-8859-7',
1038         'iso-8859-9',
1039         'iso-8859-15',
1040         'koi8-r',
1041         'koi8-u',
1042         'big5',
1043         'gb2312',
1044         'gb18030',
1045         'windows-1251',
1046         'windows-1255',
1047         'windows-1256',
1048         'tis-620',
1049         'iso-2022-jp',
1050         'euc-cn',
1051         'euc-kr',
1052         'euc-tw',
1053         'uhc',
1054         'utf7-imap');
1055
1056     $supported_encodings=array();
1057
1058     foreach ($list_of_encoding as $encoding) {
1059         // try setting encodings. suppress warning messages
1060         if (@mb_internal_encoding($encoding))
1061             $supported_encodings[]=$encoding;
1062     }
1063
1064     // restore original encoding
1065     mb_internal_encoding($orig_encoding);
1066
1067     // register list in session
1068     sqsession_register($supported_encodings,'mb_supported_encodings');
1069
1070     return $supported_encodings;
1071 }
1072
1073 /**
1074  * Callback function used to lowercase array values.
1075  * @param string $val array value
1076  * @param mixed $key array key
1077  * @since 1.5.1 and 1.4.6
1078  */
1079 function sq_lowercase_array_vals(&$val,$key) {
1080     $val = strtolower($val);
1081 }
1082
1083
1084 /**
1085  * Function returns number of characters in string.
1086  *
1087  * Returned number might be different from number of bytes in string,
1088  * if $charset is multibyte charset. Detection depends on mbstring
1089  * functions. If mbstring does not support tested multibyte charset,
1090  * vanilla string length function is used.
1091  * @param string $str string
1092  * @param string $charset charset
1093  * @since 1.5.1 and 1.4.6
1094  * @return integer number of characters in string
1095  */
1096 function sq_strlen($str, $charset=null){
1097     // default option
1098     if (is_null($charset)) return strlen($str);
1099
1100     // lowercase charset name
1101     $charset=strtolower($charset);
1102
1103     // use automatic charset detection, if function call asks for it
1104     if ($charset=='auto') {
1105         global $default_charset, $squirrelmail_language;
1106         set_my_charset();
1107         $charset=$default_charset;
1108         if ($squirrelmail_language=='ja_JP') $charset='euc-jp';
1109     }
1110
1111     // Use mbstring only with listed charsets
1112     $aList_of_mb_charsets=array('utf-8','big5','gb2312','gb18030','euc-jp','euc-cn','euc-tw','euc-kr');
1113
1114     // calculate string length according to charset
1115     if (in_array($charset,$aList_of_mb_charsets) && in_array($charset,sq_mb_list_encodings())) {
1116         $real_length = mb_strlen($str,$charset);
1117     } else {
1118         // own strlen detection code is removed because missing strpos,
1119         // strtoupper and substr implementations break string wrapping.
1120         $real_length=strlen($str);
1121     }
1122     return $real_length;
1123 }
1124
1125 /**
1126  * string padding with multibyte support
1127  *
1128  * @link http://www.php.net/str_pad
1129  * @param string $string original string
1130  * @param integer $width padded string width
1131  * @param string $pad padding symbols
1132  * @param integer $padtype padding type
1133  *  (internal php defines, see str_pad() description)
1134  * @param string $charset charset used in original string
1135  * @return string padded string
1136  */
1137 function sq_str_pad($string, $width, $pad, $padtype, $charset='') {
1138
1139     $charset = strtolower($charset);
1140     $padded_string = '';
1141
1142     switch ($charset) {
1143     case 'utf-8':
1144     case 'big5':
1145     case 'gb2312':
1146     case 'euc-kr':
1147         /*
1148          * all multibyte charsets try to increase width value by
1149          * adding difference between number of bytes and real length
1150          */
1151         $width = $width - sq_strlen($string,$charset) + strlen($string);
1152     default:
1153         $padded_string=str_pad($string,$width,$pad,$padtype);
1154     }
1155     return $padded_string;
1156 }
1157
1158 /**
1159  * Wrapper that is used to switch between vanilla and multibyte substr
1160  * functions.
1161  * @param string $string
1162  * @param integer $start
1163  * @param integer $length
1164  * @param string $charset
1165  * @return string
1166  * @since 1.5.1
1167  * @link http://www.php.net/substr
1168  * @link http://www.php.net/mb_substr
1169  */
1170 function sq_substr($string,$start,$length,$charset='auto') {
1171     // use automatic charset detection, if function call asks for it
1172     static $charset_auto, $bUse_mb;
1173
1174     if ($charset=='auto') {
1175         if (!isset($charset_auto)) {
1176             global $default_charset, $squirrelmail_language;
1177             set_my_charset();
1178             $charset=$default_charset;
1179             if ($squirrelmail_language=='ja_JP') $charset='euc-jp';
1180             $charset_auto = $charset;
1181         } else {
1182             $charset = $charset_auto;
1183         }
1184     }
1185     $charset = strtolower($charset);
1186
1187     // in_array call is expensive => do it once and use a static var for
1188     // storing the results
1189     if (!isset($bUse_mb)) {
1190         if (in_array($charset,sq_mb_list_encodings())) {
1191             $bUse_mb = true;
1192         } else {
1193             $bUse_mb = false;
1194         }
1195     }
1196
1197     if ($bUse_mb) {
1198         return mb_substr($string,$start,$length,$charset);
1199     }
1200     // TODO: add mbstring independent code
1201
1202     // use vanilla string functions as last option
1203     return substr($string,$start,$length);
1204 }
1205
1206 /**
1207  * Wrapper that is used to switch between vanilla and multibyte strpos
1208  * functions.
1209  * @param string $haystack
1210  * @param mixed $needle
1211  * @param integer $offset
1212  * @param string $charset
1213  * @return string
1214  * @since 1.5.1
1215  * @link http://www.php.net/strpos
1216  * @link http://www.php.net/mb_strpos
1217  */
1218 function sq_strpos($haystack,$needle,$offset,$charset='auto') {
1219     // use automatic charset detection, if function call asks for it
1220     static $charset_auto, $bUse_mb;
1221
1222     if ($charset=='auto') {
1223         if (!isset($charset_auto)) {
1224             global $default_charset, $squirrelmail_language;
1225             set_my_charset();
1226             $charset=$default_charset;
1227             if ($squirrelmail_language=='ja_JP') $charset='euc-jp';
1228             $charset_auto = $charset;
1229         } else {
1230             $charset = $charset_auto;
1231         }
1232     }
1233     $charset = strtolower($charset);
1234
1235     // in_array call is expensive => do it once and use a static var for
1236     // storing the results
1237     if (!isset($bUse_mb)) {
1238         if (in_array($charset,sq_mb_list_encodings())) {
1239             $bUse_mb = true;
1240         } else {
1241             $bUse_mb = false;
1242         }
1243     }
1244     if ($bUse_mb) {
1245         return mb_strpos($haystack,$needle,$offset,$charset);
1246     }
1247     // TODO: add mbstring independent code
1248
1249     // use vanilla string functions as last option
1250     return strpos($haystack,$needle,$offset);
1251 }
1252
1253 /**
1254  * Wrapper that is used to switch between vanilla and multibyte strtoupper
1255  * functions.
1256  * @param string $string
1257  * @param string $charset
1258  * @return string
1259  * @since 1.5.1
1260  * @link http://www.php.net/strtoupper
1261  * @link http://www.php.net/mb_strtoupper
1262  */
1263 function sq_strtoupper($string,$charset='auto') {
1264     // use automatic charset detection, if function call asks for it
1265     static $charset_auto, $bUse_mb;
1266
1267     if ($charset=='auto') {
1268         if (!isset($charset_auto)) {
1269             global $default_charset, $squirrelmail_language;
1270             set_my_charset();
1271             $charset=$default_charset;
1272             if ($squirrelmail_language=='ja_JP') $charset='euc-jp';
1273             $charset_auto = $charset;
1274         } else {
1275             $charset = $charset_auto;
1276         }
1277     }
1278     $charset = strtolower($charset);
1279
1280     // in_array call is expensive => do it once and use a static var for
1281     // storing the results
1282     if (!isset($bUse_mb)) {
1283         if (function_exists('mb_strtoupper') &&
1284             in_array($charset,sq_mb_list_encodings())) {
1285             $bUse_mb = true;
1286         } else {
1287             $bUse_mb = false;
1288         }
1289     }
1290
1291     if ($bUse_mb) {
1292         return mb_strtoupper($string,$charset);
1293     }
1294     // TODO: add mbstring independent code
1295
1296     // use vanilla string functions as last option
1297     return strtoupper($string);
1298 }
1299
1300 /**
1301  * Counts 8bit bytes in string
1302  * @param string $string tested string
1303  * @return integer number of 8bit bytes
1304  */
1305 function sq_count8bit($string) {
1306     $count=0;
1307     for ($i=0; $i<strlen($string); $i++) {
1308         if (ord($string[$i]) > 127) $count++;
1309     }
1310     return $count;
1311 }
1312
1313 /**
1314  * Callback function to trim whitespace from a value, to be used in array_walk
1315  * @param string $value value to trim
1316  * @since 1.5.2 and 1.4.7
1317  */
1318 function sq_trim_value ( &$value ) {
1319     $value = trim($value);
1320 }