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; 1999-2006 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  * If this doesnt work correctly for you (although it should), you can
 464  * remove all this code except the last two lines, and have it return
 465  * the right URL for your site, something like:
 466  *
 467  *   http://www.example.com/squirrelmail/
 468  *
 469  * @return string the base url for this SquirrelMail installation
 470  * @since 1.0
 471  */
 472 function get_location () {
 473
 474     global $imap_server_type;
 475
 476     /* Get the path, handle virtual directories */
 477     if(strpos(php_self(), '?')) {
 478         $path = substr(php_self(), 0, strpos(php_self(), '?'));
 479     } else {
 480         $path = php_self();
 481     }
 482     $path = substr($path, 0, strrpos($path, '/'));
 483     if ( sqgetGlobalVar('sq_base_url', $full_url, SQ_SESSION) ) {
 484       return $full_url . $path;
 485     }
 486
 487     /* Check if this is a HTTPS or regular HTTP request. */
 488     $proto = 'http://';
 489
 490     /*
 491      * If you have 'SSLOptions +StdEnvVars' in your apache config
 492      *     OR if you have HTTPS=on in your HTTP_SERVER_VARS
 493      *     OR if you are on port 443
 494      */
 495     $getEnvVar = getenv('HTTPS');
 496     if ((isset($getEnvVar) && !strcasecmp($getEnvVar, 'on')) ||
 497         (sqgetGlobalVar('HTTPS', $https_on, SQ_SERVER) && !strcasecmp($https_on, 'on')) ||
 498         (sqgetGlobalVar('SERVER_PORT', $server_port, SQ_SERVER) &&  $server_port == 443)) {
 499         $proto = 'https://';
 500     }
 501
 502     /* Get the hostname from the Host header or server config. */
 503     if ( !sqgetGlobalVar('HTTP_HOST', $host, SQ_SERVER) || empty($host) ) {
 504       if ( !sqgetGlobalVar('SERVER_NAME', $host, SQ_SERVER) || empty($host) ) {
 505         $host = '';
 506       }
 507     }
 508
 509     $port = '';
 510     if (! strstr($host, ':')) {
 511         if (sqgetGlobalVar('SERVER_PORT', $server_port, SQ_SERVER)) {
 512             if (($server_port != 80 && $proto == 'http://') ||
 513                 ($server_port != 443 && $proto == 'https://')) {
 514                 $port = sprintf(':%d', $server_port);
 515             }
 516         }
 517     }
 518
 519    /* this is a workaround for the weird macosx caching that
 520       causes Apache to return 16080 as the port number, which causes
 521       SM to bail */
 522
 523    if ($imap_server_type == 'macosx' && $port == ':16080') {
 524         $port = '';
 525    }
 526
 527    /* Fallback is to omit the server name and use a relative */
 528    /* URI, although this is not RFC 2616 compliant.          */
 529    $full_url = ($host ? $proto . $host . $port : '');
 530    sqsession_register($full_url, 'sq_base_url');
 531    return $full_url . $path;
 532 }
 533
 534
 535 /**
 536  * Encrypts password
 537  *
 538  * These functions are used to encrypt the password before it is
 539  * stored in a cookie. The encryption key is generated by
 540  * OneTimePadCreate();
 541  *
 542  * @param string $string the (password)string to encrypt
 543  * @param string $epad the encryption key
 544  * @return string the base64-encoded encrypted password
 545  * @since 1.0
 546  */
 547 function OneTimePadEncrypt ($string, $epad) {
 548     $pad = base64_decode($epad);
 549
 550     if (strlen($pad)>0) {
 551         // make sure that pad is longer than string
 552         while (strlen($string)>strlen($pad)) {
 553             $pad.=$pad;
 554         }
 555     } else {
 556         // FIXME: what should we do when $epad is not base64 encoded or empty.
 557     }
 558
 559     $encrypted = '';
 560     for ($i = 0; $i < strlen ($string); $i++) {
 561         $encrypted .= chr (ord($string[$i]) ^ ord($pad[$i]));
 562     }
 563
 564     return base64_encode($encrypted);
 565 }
 566
 567 /**
 568  * Decrypts a password from the cookie
 569  *
 570  * Decrypts a password from the cookie, encrypted by OneTimePadEncrypt.
 571  * This uses the encryption key that is stored in the session.
 572  *
 573  * @param string $string the string to decrypt
 574  * @param string $epad the encryption key from the session
 575  * @return string the decrypted password
 576  * @since 1.0
 577  */
 578 function OneTimePadDecrypt ($string, $epad) {
 579     $pad = base64_decode($epad);
 580
 581     if (strlen($pad)>0) {
 582         // make sure that pad is longer than string
 583         while (strlen($string)>strlen($pad)) {
 584             $pad.=$pad;
 585         }
 586     } else {
 587         // FIXME: what should we do when $epad is not base64 encoded or empty.
 588     }
 589
 590     $encrypted = base64_decode ($string);
 591     $decrypted = '';
 592     for ($i = 0; $i < strlen ($encrypted); $i++) {
 593         $decrypted .= chr (ord($encrypted[$i]) ^ ord($pad[$i]));
 594     }
 595
 596     return $decrypted;
 597 }
 598
 599
 600 /**
 601  * Randomizes the mt_rand() function.
 602  *
 603  * Toss this in strings or integers and it will seed the generator
 604  * appropriately. With strings, it is better to get them long.
 605  * Use md5() to lengthen smaller strings.
 606  *
 607  * @param mixed $val a value to seed the random number generator. mixed = integer or string.
 608  * @return void
 609  * @since 1.0
 610  */
 611 function sq_mt_seed($Val) {
 612     /* if mt_getrandmax() does not return a 2^n - 1 number,
 613        this might not work well.  This uses $Max as a bitmask. */
 614     $Max = mt_getrandmax();
 615
 616     if (! is_int($Val)) {
 617             $Val = crc32($Val);
 618     }
 619
 620     if ($Val < 0) {
 621         $Val *= -1;
 622     }
 623
 624     if ($Val == 0) {
 625         return;
 626     }
 627
 628     mt_srand(($Val ^ mt_rand(0, $Max)) & $Max);
 629 }
 630
 631
 632 /**
 633  * Init random number generator
 634  *
 635  * This function initializes the random number generator fairly well.
 636  * It also only initializes it once, so you don't accidentally get
 637  * the same 'random' numbers twice in one session.
 638  *
 639  * @return void
 640  * @since 1.0
 641  */
 642 function sq_mt_randomize() {
 643     static $randomized;
 644
 645     if ($randomized) {
 646         return;
 647     }
 648
 649     /* Global. */
 650     sqgetGlobalVar('REMOTE_PORT', $remote_port, SQ_SERVER);
 651     sqgetGlobalVar('REMOTE_ADDR', $remote_addr, SQ_SERVER);
 652     sq_mt_seed((int)((double) microtime() * 1000000));
 653     sq_mt_seed(md5($remote_port . $remote_addr . getmypid()));
 654
 655     /* getrusage */
 656     if (function_exists('getrusage')) {
 657         /* Avoid warnings with Win32 */
 658         $dat = @getrusage();
 659         if (isset($dat) && is_array($dat)) {
 660             $Str = '';
 661             foreach ($dat as $k => $v)
 662                 {
 663                     $Str .= $k . $v;
 664                 }
 665             sq_mt_seed(md5($Str));
 666         }
 667     }
 668
 669     if(sqgetGlobalVar('UNIQUE_ID', $unique_id, SQ_SERVER)) {
 670         sq_mt_seed(md5($unique_id));
 671     }
 672
 673     $randomized = 1;
 674 }
 675
 676 /**
 677  * Creates encryption key
 678  *
 679  * Creates an encryption key for encrypting the password stored in the cookie.
 680  * The encryption key itself is stored in the session.
 681  *
 682  * Pad must be longer or equal to encoded string length in 1.4.4/1.5.0 and older.
 683  * @param int $length optional, length of the string to generate
 684  * @return string the encryption key
 685  * @since 1.0
 686  */
 687 function OneTimePadCreate ($length=100) {
 688     sq_mt_randomize();
 689
 690     $pad = '';
 691     for ($i = 0; $i < $length; $i++) {
 692         $pad .= chr(mt_rand(0,255));
 693     }
 694
 695     return base64_encode($pad);
 696 }
 697
 698 /**
 699  * Returns a string showing the size of the message/attachment.
 700  *
 701  * @param int $bytes the filesize in bytes
 702  * @return string the filesize in human readable format
 703  * @since 1.0
 704  */
 705 function show_readable_size($bytes) {
 706     $bytes /= 1024;
 707     $type = 'k';
 708
 709     if ($bytes / 1024 > 1) {
 710         $bytes /= 1024;
 711         $type = 'M';
 712     }
 713
 714     if ($bytes < 10) {
 715         $bytes *= 10;
 716         settype($bytes, 'integer');
 717         $bytes /= 10;
 718     } else {
 719         settype($bytes, 'integer');
 720     }
 721
 722     return $bytes . '&nbsp;' . $type;
 723 }
 724
 725 /**
 726  * Generates a random string from the character set you pass in
 727  *
 728  * @param int $size the length of the string to generate
 729  * @param string $chars a string containing the characters to use
 730  * @param int $flags a flag to add a specific set to the characters to use:
 731  *     Flags:
 732  *       1 = add lowercase a-z to $chars
 733  *       2 = add uppercase A-Z to $chars
 734  *       4 = add numbers 0-9 to $chars
 735  * @return string the random string
 736  * @since 1.0
 737  */
 738 function GenerateRandomString($size, $chars, $flags = 0) {
 739     if ($flags & 0x1) {
 740         $chars .= 'abcdefghijklmnopqrstuvwxyz';
 741     }
 742     if ($flags & 0x2) {
 743         $chars .= 'ABCDEFGHIJKLMNOPQRSTUVWXYZ';
 744     }
 745     if ($flags & 0x4) {
 746         $chars .= '0123456789';
 747     }
 748
 749     if (($size < 1) || (strlen($chars) < 1)) {
 750         return '';
 751     }
 752
 753     sq_mt_randomize(); /* Initialize the random number generator */
 754
 755     $String = '';
 756     $j = strlen( $chars ) - 1;
 757     while (strlen($String) < $size) {
 758         $String .= $chars{mt_rand(0, $j)};
 759     }
 760
 761     return $String;
 762 }
 763
 764 /**
 765  * Escapes special characters for use in IMAP commands.
 766  *
 767  * @param string $str the string to escape
 768  * @return string the escaped string
 769  * @since 1.0.3
 770  */
 771 function quoteimap($str) {
 772     return preg_replace("/([\"\\\\])/", "\\\\$1", $str);
 773 }
 774
 775 /**
 776  * Trims array
 777  *
 778  * Trims every element in the array, ie. remove the first char of each element
 779  * @param array $array the array to trim
 780  * @since 1.2.0
 781  */
 782 function TrimArray(&$array) {
 783     foreach ($array as $k => $v) {
 784         global $$k;
 785         if (is_array($$k)) {
 786             foreach ($$k as $k2 => $v2) {
 787                 $$k[$k2] = substr($v2, 1);
 788             }
 789         } else {
 790             $$k = substr($v, 1);
 791         }
 792
 793         /* Re-assign back to array. */
 794         $array[$k] = $$k;
 795     }
 796 }
 797
 798 /**
 799  * Create compose link
 800  *
 801  * Returns a link to the compose-page, taking in consideration
 802  * the compose_in_new and javascript settings.
 803  * @param string $url the URL to the compose page
 804  * @param string $text the link text, default "Compose"
 805  * @param string $target (since 1.4.3) url target
 806  * @return string a link to the compose page
 807  * @since 1.4.2
 808  */
 809 function makeComposeLink($url, $text = null, $target='') {
 810     global $compose_new_win,$javascript_on, $compose_width, $compose_height;
 811
 812     if(!$text) {
 813         $text = _("Compose");
 814     }
 815
 816     // if not using "compose in new window", make
 817     // regular link and be done with it
 818     if($compose_new_win != '1') {
 819         return makeInternalLink($url, $text, $target);
 820     }
 821
 822     // build the compose in new window link...
 823
 824
 825     // if javascript is on, use onclick event to handle it
 826     if($javascript_on) {
 827         sqgetGlobalVar('base_uri', $base_uri, SQ_SESSION);
 828         $compuri = $base_uri.$url;
 829         return "<a href=\"javascript:void(0)\" onclick=\"comp_in_new('$compuri','$compose_width','$compose_height')\">$text</a>";
 830     }
 831
 832     // otherwise, just open new window using regular HTML
 833     return makeInternalLink($url, $text, '_blank');
 834 }
 835
 836 /**
 837  * Print variable
 838  *
 839  * sm_print_r($some_variable, [$some_other_variable [, ...]]);
 840  *
 841  * Debugging function - does the same as print_r, but makes sure special
 842  * characters are converted to htmlentities first.  This will allow
 843  * values like <some@email.address> to be displayed.
 844  * The output is wrapped in <<pre>> and <</pre>> tags.
 845  * Since 1.4.2 accepts unlimited number of arguments.
 846  * @since 1.4.1
 847  * @return void
 848  */
 849 function sm_print_r() {
 850     ob_start();  // Buffer output
 851     foreach(func_get_args() as $var) {
 852         print_r($var);
 853         echo "\n";
 854         // php has get_class_methods function that can print class methods
 855         if (is_object($var)) {
 856             // get class methods if $var is object
 857             $aMethods=get_class_methods(get_class($var));
 858             // make sure that $aMethods is array and array is not empty
 859             if (is_array($aMethods) && $aMethods!=array()) {
 860                 echo "Object methods:\n";
 861                 foreach($aMethods as $method) {
 862                     echo '* ' . $method . "\n";
 863                 }
 864             }
 865             echo "\n";
 866         }
 867     }
 868     $buffer = ob_get_contents(); // Grab the print_r output
 869     ob_end_clean();  // Silently discard the output & stop buffering
 870     print '<div align="left"><pre>';
 871     print htmlentities($buffer);
 872     print '</pre></div>';
 873 }
 874
 875 /**
 876  * version of fwrite which checks for failure
 877  * @param resource $fp
 878  * @param string $string
 879  * @return number of written bytes. false on failure
 880  * @since 1.4.3
 881  */
 882 function sq_fwrite($fp, $string) {
 883         // write to file
 884         $count = @fwrite($fp,$string);
 885         // the number of bytes written should be the length of the string
 886         if($count != strlen($string)) {
 887                 return FALSE;
 888         }
 889
 890         return $count;
 891 }
 892
 893 /**
 894  * sq_get_html_translation_table
 895  *
 896  * Returns the translation table used by sq_htmlentities()
 897  *
 898  * @param integer $table html translation table. Possible values (without quotes):
 899  *             <ul>
 900  *                <li>HTML_ENTITIES - full html entities table defined by charset</li>
 901  *                <li>HTML_SPECIALCHARS - html special characters table</li>
 902  *             </ul>
 903  * @param integer $quote_style quote encoding style. Possible values (without quotes):
 904  *              <ul>
 905  *                <li>ENT_COMPAT - (default) encode double quotes</li>
 906  *                <li>ENT_NOQUOTES -  don't encode double or single quotes</li>
 907  *                <li>ENT_QUOTES - encode double and single quotes</li>
 908  *              </ul>
 909  * @param string $charset charset used for encoding. default to us-ascii, 'auto' uses $default_charset global value.
 910  * @return array html translation array
 911  * @since 1.5.1
 912  */
 913 function sq_get_html_translation_table($table,$quote_style=ENT_COMPAT,$charset='us-ascii') {
 914   global $default_charset;
 915
 916   if ($table == HTML_SPECIALCHARS) $charset='us-ascii';
 917
 918   // Start array with ampersand
 919   $sq_html_ent_table = array( "&" => '&amp;' );
 920
 921   // < and >
 922   $sq_html_ent_table = array_merge($sq_html_ent_table,
 923                         array("<" => '&lt;',
 924                               ">" => '&gt;')
 925                         );
 926   // double quotes
 927   if ($quote_style == ENT_COMPAT)
 928      $sq_html_ent_table = array_merge($sq_html_ent_table,
 929                             array("\"" => '&quot;')
 930                             );
 931
 932   // double and single quotes
 933   if ($quote_style == ENT_QUOTES)
 934      $sq_html_ent_table = array_merge($sq_html_ent_table,
 935                             array("\"" => '&quot;',
 936                               "'" => '&#39;')
 937                             );
 938
 939   if ($charset=='auto') $charset=$default_charset;
 940
 941   // add entities that depend on charset
 942   switch($charset){
 943   case 'iso-8859-1':
 944     include_once(SM_PATH . 'functions/htmlentities/iso-8859-1.php');
 945     break;
 946   case 'utf-8':
 947     include_once(SM_PATH . 'functions/htmlentities/utf-8.php');
 948     break;
 949   case 'us-ascii':
 950   default:
 951     break;
 952   }
 953   // return table
 954   return $sq_html_ent_table;
 955 }
 956
 957 /**
 958  * sq_htmlentities
 959  *
 960  * Convert all applicable characters to HTML entities.
 961  * Minimal php requirement - v.4.0.5.
 962  *
 963  * Function is designed for people that want to use full power of htmlentities() in
 964  * i18n environment.
 965  *
 966  * @param string $string string that has to be sanitized
 967  * @param integer $quote_style quote encoding style. Possible values (without quotes):
 968  *              <ul>
 969  *                <li>ENT_COMPAT - (default) encode double quotes</li>
 970  *                <li>ENT_NOQUOTES - don't encode double or single quotes</li>
 971  *                <li>ENT_QUOTES - encode double and single quotes</li>
 972  *              </ul>
 973  * @param string $charset charset used for encoding. defaults to 'us-ascii', 'auto' uses $default_charset global value.
 974  * @return string sanitized string
 975  * @since 1.5.1
 976  */
 977 function sq_htmlentities($string,$quote_style=ENT_COMPAT,$charset='us-ascii') {
 978   // get translation table
 979   $sq_html_ent_table=sq_get_html_translation_table(HTML_ENTITIES,$quote_style,$charset);
 980   // convert characters
 981   return str_replace(array_keys($sq_html_ent_table),array_values($sq_html_ent_table),$string);
 982 }
 983
 984 /**
 985  * Tests if string contains 8bit symbols.
 986  *
 987  * If charset is not set, function defaults to default_charset.
 988  * $default_charset global must be set correctly if $charset is
 989  * not used.
 990  * @param string $string tested string
 991  * @param string $charset charset used in a string
 992  * @return bool true if 8bit symbols are detected
 993  * @since 1.5.1 and 1.4.4
 994  */
 995 function sq_is8bit($string,$charset='') {
 996     global $default_charset;
 997
 998     if ($charset=='') $charset=$default_charset;
 999
1000     /**
1001      * Don't use \240 in ranges. Sometimes RH 7.2 doesn't like it.
1002      * Don't use \200-\237 for iso-8859-x charsets. This range
1003      * stores control symbols in those charsets.
1004      * Use preg_match instead of ereg in order to avoid problems
1005      * with mbstring overloading
1006      */
1007     if (preg_match("/^iso-8859/i",$charset)) {
1008         $needle='/\240|[\241-\377]/';
1009     } else {
1010         $needle='/[\200-\237]|\240|[\241-\377]/';
1011     }
1012     return preg_match("$needle",$string);
1013 }
1014
1015 /**
1016  * Replacement of mb_list_encodings function
1017  *
1018  * This function provides replacement for function that is available only
1019  * in php 5.x. Function does not test all mbstring encodings. Only the ones
1020  * that might be used in SM translations.
1021  *
1022  * Supported strings are stored in session in order to reduce number of
1023  * mb_internal_encoding function calls.
1024  *
1025  * If you want to test all mbstring encodings - fill $list_of_encodings
1026  * array.
1027  * @return array list of encodings supported by php mbstring extension
1028  * @since 1.5.1 and 1.4.6
1029  */
1030 function sq_mb_list_encodings() {
1031     if (! function_exists('mb_internal_encoding'))
1032         return array();
1033
1034     // php 5+ function
1035     if (function_exists('mb_list_encodings')) {
1036         $ret = mb_list_encodings();
1037         array_walk($ret,'sq_lowercase_array_vals');
1038         return $ret;
1039     }
1040
1041     // don't try to test encodings, if they are already stored in session
1042     if (sqgetGlobalVar('mb_supported_encodings',$mb_supported_encodings,SQ_SESSION))
1043         return $mb_supported_encodings;
1044
1045     // save original encoding
1046     $orig_encoding=mb_internal_encoding();
1047
1048     $list_of_encoding=array(
1049         'pass',
1050         'auto',
1051         'ascii',
1052         'jis',
1053         'utf-8',
1054         'sjis',
1055         'euc-jp',
1056         'iso-8859-1',
1057         'iso-8859-2',
1058         'iso-8859-7',
1059         'iso-8859-9',
1060         'iso-8859-15',
1061         'koi8-r',
1062         'koi8-u',
1063         'big5',
1064         'gb2312',
1065         'gb18030',
1066         'windows-1251',
1067         'windows-1255',
1068         'windows-1256',
1069         'tis-620',
1070         'iso-2022-jp',
1071         'euc-cn',
1072         'euc-kr',
1073         'euc-tw',
1074         'uhc',
1075         'utf7-imap');
1076
1077     $supported_encodings=array();
1078
1079     foreach ($list_of_encoding as $encoding) {
1080         // try setting encodings. suppress warning messages
1081         if (@mb_internal_encoding($encoding))
1082             $supported_encodings[]=$encoding;
1083     }
1084
1085     // restore original encoding
1086     mb_internal_encoding($orig_encoding);
1087
1088     // register list in session
1089     sqsession_register($supported_encodings,'mb_supported_encodings');
1090
1091     return $supported_encodings;
1092 }
1093
1094 /**
1095  * Callback function used to lowercase array values.
1096  * @param string $val array value
1097  * @param mixed $key array key
1098  * @since 1.5.1 and 1.4.6
1099  */
1100 function sq_lowercase_array_vals(&$val,$key) {
1101     $val = strtolower($val);
1102 }
1103
1104
1105 /**
1106  * Function returns number of characters in string.
1107  *
1108  * Returned number might be different from number of bytes in string,
1109  * if $charset is multibyte charset. Detection depends on mbstring
1110  * functions. If mbstring does not support tested multibyte charset,
1111  * vanilla string length function is used.
1112  * @param string $str string
1113  * @param string $charset charset
1114  * @since 1.5.1 and 1.4.6
1115  * @return integer number of characters in string
1116  */
1117 function sq_strlen($str, $charset=null){
1118     // default option
1119     if (is_null($charset)) return strlen($str);
1120
1121     // lowercase charset name
1122     $charset=strtolower($charset);
1123
1124     // use automatic charset detection, if function call asks for it
1125     if ($charset=='auto') {
1126         global $default_charset, $squirrelmail_language;
1127         set_my_charset();
1128         $charset=$default_charset;
1129         if ($squirrelmail_language=='ja_JP') $charset='euc-jp';
1130     }
1131
1132     // Use mbstring only with listed charsets
1133     $aList_of_mb_charsets=array('utf-8','big5','gb2312','gb18030','euc-jp','euc-cn','euc-tw','euc-kr');
1134
1135     // calculate string length according to charset
1136     if (in_array($charset,$aList_of_mb_charsets) && in_array($charset,sq_mb_list_encodings())) {
1137         $real_length = mb_strlen($str,$charset);
1138     } else {
1139         // own strlen detection code is removed because missing strpos,
1140         // strtoupper and substr implementations break string wrapping.
1141         $real_length=strlen($str);
1142     }
1143     return $real_length;
1144 }
1145
1146 /**
1147  * string padding with multibyte support
1148  *
1149  * @link http://www.php.net/str_pad
1150  * @param string $string original string
1151  * @param integer $width padded string width
1152  * @param string $pad padding symbols
1153  * @param integer $padtype padding type
1154  *  (internal php defines, see str_pad() description)
1155  * @param string $charset charset used in original string
1156  * @return string padded string
1157  */
1158 function sq_str_pad($string, $width, $pad, $padtype, $charset='') {
1159
1160     $charset = strtolower($charset);
1161     $padded_string = '';
1162
1163     switch ($charset) {
1164     case 'utf-8':
1165     case 'big5':
1166     case 'gb2312':
1167     case 'euc-kr':
1168         /*
1169          * all multibyte charsets try to increase width value by
1170          * adding difference between number of bytes and real length
1171          */
1172         $width = $width - sq_strlen($string,$charset) + strlen($string);
1173     default:
1174         $padded_string=str_pad($string,$width,$pad,$padtype);
1175     }
1176     return $padded_string;
1177 }
1178
1179 /**
1180  * Wrapper that is used to switch between vanilla and multibyte substr
1181  * functions.
1182  * @param string $string
1183  * @param integer $start
1184  * @param integer $length
1185  * @param string $charset
1186  * @return string
1187  * @since 1.5.1
1188  * @link http://www.php.net/substr
1189  * @link http://www.php.net/mb_substr
1190  */
1191 function sq_substr($string,$start,$length,$charset='auto') {
1192     // use automatic charset detection, if function call asks for it
1193     if ($charset=='auto') {
1194         global $default_charset, $squirrelmail_language;
1195         set_my_charset();
1196         $charset=$default_charset;
1197         if ($squirrelmail_language=='ja_JP') $charset='euc-jp';
1198     }
1199     $charset = strtolower($charset);
1200     if (function_exists('mb_internal_encoding') &&
1201         in_array($charset,sq_mb_list_encodings())) {
1202         return mb_substr($string,$start,$length,$charset);
1203     }
1204     // TODO: add mbstring independent code
1205
1206     // use vanilla string functions as last option
1207     return substr($string,$start,$length);
1208 }
1209
1210 /**
1211  * Wrapper that is used to switch between vanilla and multibyte strpos
1212  * functions.
1213  * @param string $haystack
1214  * @param mixed $needle
1215  * @param integer $offset
1216  * @param string $charset
1217  * @return string
1218  * @since 1.5.1
1219  * @link http://www.php.net/strpos
1220  * @link http://www.php.net/mb_strpos
1221  */
1222 function sq_strpos($haystack,$needle,$offset,$charset='auto') {
1223     // use automatic charset detection, if function call asks for it
1224     if ($charset=='auto') {
1225         global $default_charset, $squirrelmail_language;
1226         set_my_charset();
1227         $charset=$default_charset;
1228         if ($squirrelmail_language=='ja_JP') $charset='euc-jp';
1229     }
1230     $charset = strtolower($charset);
1231     if (function_exists('mb_internal_encoding') &&
1232         in_array($charset,sq_mb_list_encodings())) {
1233         return mb_strpos($haystack,$needle,$offset,$charset);
1234     }
1235     // TODO: add mbstring independent code
1236
1237     // use vanilla string functions as last option
1238     return strpos($haystack,$needle,$offset);
1239 }
1240
1241 /**
1242  * Wrapper that is used to switch between vanilla and multibyte strtoupper
1243  * functions.
1244  * @param string $string
1245  * @param string $charset
1246  * @return string
1247  * @since 1.5.1
1248  * @link http://www.php.net/strtoupper
1249  * @link http://www.php.net/mb_strtoupper
1250  */
1251 function sq_strtoupper($string,$charset='auto') {
1252     // use automatic charset detection, if function call asks for it
1253     if ($charset=='auto') {
1254         global $default_charset,$squirrelmail_language;
1255         set_my_charset();
1256         $charset=$default_charset;
1257         if ($squirrelmail_language=='ja_JP') $charset='euc-jp';
1258     }
1259     $charset = strtolower($charset);
1260     if (function_exists('mb_strtoupper') &&
1261         in_array($charset,sq_mb_list_encodings())) {
1262         return mb_strtoupper($string,$charset);
1263     }
1264     // TODO: add mbstring independent code
1265
1266     // use vanilla string functions as last option
1267     return strtoupper($string);
1268 }
1269
1270 /**
1271  * Counts 8bit bytes in string
1272  * @param string $string tested string
1273  * @return integer number of 8bit bytes
1274  */
1275 function sq_count8bit($string) {
1276     $count=0;
1277     for ($i=0; $i<strlen($string); $i++) {
1278         if (ord($string[$i]) > 127) $count++;
1279     }
1280     return $count;
1281 }
1282
1283 ?>