1 <?php

     2 

     3 define('CHARSET_HEX', '0123456789abcdef');

     4 define('CHARSET_MODHEX', 'cbdefghijklnrtuv');

     5 define('CHARSET_BASE64', 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=');

     6 

     7 function yms_modhex_encode($str)

     8 {

     9   if ( !preg_match('/^[' . CHARSET_HEX . ']+$/', $str) )

    10     $str = yms_hex_encode($str);

    11   

    12   return strtr($str, '0123456789abcdef', 'cbdefghijklnrtuv');

    13 }

    14 

    15 function yms_modhex_decode($str)

    16 {

    17   if ( !preg_match('/^[' . CHARSET_MODHEX . ']+$/', $str) )

    18     return false;

    19   

    20   return strtr($str, 'cbdefghijklnrtuv', '0123456789abcdef');

    21 }

    22 

    23 function yms_hex_decode($str)

    24 {

    25   if ( !preg_match('/^[' . CHARSET_HEX . ']+$/', $str) )

    26     return false;

    27   

    28   if ( strlen($str) % 2 != 0 )

    29     return '';

    30   

    31   $return = '';

    32   for ( $i = 0; $i < strlen($str); $i+=2 )

    33   {

    34     $chr = substr($str, $i, 2);

    35     $return .= chr(intval(hexdec($chr)));

    36   }

    37   return $return;

    38 }

    39 

    40 function yms_hex_encode($str)

    41 {

    42   $return = '';

    43   for ( $i = 0; $i < strlen($str); $i++ )

    44   {

    45     $chr = dechex(ord($str{$i}));

    46     if ( strlen($chr) < 2 )

    47       $chr = "0$chr";

    48     $return .= $chr;

    49   }

    50   return $return;

    51 }

    52 

    53 function yms_tobinary($str)

    54 {

    55   if ( preg_match('/^[' . CHARSET_HEX . ']+$/', $str) )

    56   {

    57     return yms_hex_decode($str);

    58   }

    59   else if ( preg_match('/^[' . CHARSET_MODHEX . ']+$/', $str) )

    60   {

    61     return yms_hex_decode(yms_modhex_decode($str));

    62   }

    63   else if ( preg_match('#^[' . CHARSET_BASE64 . ']+$#', $str) )

    64   {

    65     return base64_decode($str);

    66   }

    67   return $str;

    68 }

    69 

    70 function yms_randbin($len)

    71 {

    72   $ret = '';

    73   for ( $i = 0; $i < $len; $i++ )

    74   {

    75     $ret .= chr(mt_rand(0, 255));

    76   }

    77   return $ret;

    78 }

    79