function __construct($name, DH $dh)
{
$this->name = $name;
$this->dh = $dh;
$this->priv = $dh->generatePrivate();
$this->pub = $dh->generatePublic($this->priv);
}
}
function generateShared($private, $public)
{
return gmp_powm($public, $private, $this->p);
}
function p()
{
return gmp_strval($this->p, 16);
}
function g($val = null)
{
if (is_string($val)) {
$this->g = gmp_init($val, 16);
}
return gmp_strval($this->g, 16);
}
}
// don't output if we're included into another script.
if (!debug_backtrace()) {
$dh = new DH();
$a = $dh->generatePrivate();
$b = $dh->generatePrivate();
$A = $dh->generatePublic($a);
$B = $dh->generatePublic($b);
$s = $dh->generateShared($a, $B);
$s2 = $dh->generateShared($b, $A);
print "A and B shared secrets match:\n";
print gmp_cmp($s, $s2) === 0 ? "Yes!\n\n" : "No :(\n\n";
print "Shared secret:\n";
print gmp_strval($s, 16) . "\n\n";
}