Subversion Repositories oidplus

Rev

Rev 1042 | Show entire file | Regard whitespace | Details | Blame | Last modification | View Log | RSS feed

Rev 1042 Rev 1439
Line 46... Line 46...
46 
     * Default constructor
 46 
     * Default constructor
47 
     */
 47 
     */
48 
    public function __construct(...$indices)
 48 
    public function __construct(...$indices)
49 
    {
 49 
    {
50 
        $m = array_shift($indices);
 50 
        $m = array_shift($indices);
- 
 
 51 
        if ($m > 571) {
- 
 
 52 
            /* sect571r1 and sect571k1 are the largest binary curves that https://www.secg.org/sec2-v2.pdf defines
- 
 
 53 
               altho theoretically there may be legit reasons to use binary finite fields with larger degrees
- 
 
 54 
               imposing a limit on the maximum size is both reasonable and precedented. in particular,
- 
 
 55 
               http://tools.ietf.org/html/rfc4253#section-6.1 (The Secure Shell (SSH) Transport Layer Protocol) says
- 
 
 56 
               "implementations SHOULD check that the packet length is reasonable in order for the implementation to
- 
 
 57 
                avoid denial of service and/or buffer overflow attacks" */
- 
 
 58 
            throw new \OutOfBoundsException('Degrees larger than 571 are not supported');
- 
 
 59 
        }
51 
        $val = str_repeat('0', $m) . '1';
 60 
        $val = str_repeat('0', $m) . '1';
52 
        foreach ($indices as $index) {
 61 
        foreach ($indices as $index) {
53 
            $val[$index] = '1';
 62 
            $val[$index] = '1';
54 
        }
 63 
        }
55 
        $modulo = static::base2ToBase256(strrev($val));
 64 
        $modulo = static::base2ToBase256(strrev($val));