asn.php

См. документацию.

<?
class CASNReader
{
    protected $value;
 
    public function __construct($value='')
    {
        $this->value = $value;
    }
 
    public function Read(&$buf)
    {
        self::ReadByte($buf);
        $size = self::ReadByte($buf);
    
        if($size > 127) 
        {
            $sizeLen = $size - 0x80;
            $size = self::ToInt(self::ReadBytes($buf, $sizeLen));
        }
    
        $this->value = self::ReadBytes($buf, $size);
    }
 
    protected static function ReadBytes(&$buf, $len)
    {
        $res = substr($buf, 0, $len);
        $buf = substr($buf, $len);
        
        return $res;
    }
    
    protected static function ReadByte(&$buf)
    {
        return ord(self::ReadBytes($buf, 1));
    }
 
    protected static function ToInt($bin)
    {
        $result = 0;
        $len = strlen($bin);
        for($i=0; $i<$len; $i++) 
        {
            $byte = self::ReadByte($bin);
            $result += $byte << (($len-$i-1)*8);
        }
        return $result;
    }
 
    public function GetValue()    
    {
        $result = $this->value;
        if(ord($result[0]) == 0x00)
            $result = substr($result, 1);
        return $result;
    }
 
    public function GetSequence()
    {
        $arResult = array();
        $val = $this->value;
        while($val <> '')
        {
            $sequence = new CASNReader();
            $sequence->Read($val);
            $arResult[] = $sequence;
        }  
        return $arResult;
    }
}
?>