/**
* @see AbstractKeyInstance::deserializeFromObject($obj)
*/
protected function deserializeFromObject($obj)
{
$n = new MathBigInteger($obj["n"]);
$e = new MathBigInteger($obj["e"]);
$array = array("n" => $n, "e" => $e);
$this->rsa->loadKey($array, CRYPT_RSA_PUBLIC_FORMAT_RAW);
$this->rsa->setPublicKey($array, CRYPT_RSA_PUBLIC_FORMAT_RAW);
$this->keysize = RSAKeyPair::_getKeySizeFromRSAKeySize(strlen($n->toBits()));
$this->rsa->setHash(RSAKeyPair::$KEYSIZES[$this->keysize]["hashAlg"]);
return $this;
}
/**
* @see AbstractKeyInstance::serializeToObject($obj)
*/
protected function serializeToObject(&$obj)
{
$obj["p"] = $this->key_p->toHex();
$obj["q"] = $this->key_q->toHex();
$obj["g"] = $this->key_g->toHex();
$obj["x"] = $this->key_x->toHex();
}
/**
* RSAVP1
*
* See {@link http://tools.ietf.org/html/rfc3447#section-5.2.2 RFC3447#section-5.2.2}.
*
* @access private
* @param MathBigInteger $s
* @return MathBigInteger
*/
function _rsavp1($s)
{
if ($s->compare($this->zero) < 0 || $s->compare($this->modulus) > 0) {
user_error('Signature representative out of range', E_USER_NOTICE);
return false;
}
return $this->_exponentiate($s);
}
/**
* @see AbstractPublicKey::verify($message, $signature)
*/
public function verify($message, $signature)
{
$params = DSAKeyPair::$KEYSIZES[$this->keysize];
$hash_alg = $params["hashAlg"];
$hexlength = $params["q_bitlength"] / 4;
// we pre-pad with 0s because encoding may have gotten rid of some
$signature = Utils::hex_lpad(bin2hex($signature), $hexlength * 2);
// now this should only happen if the signature was longer
if (strlen($signature) != $hexlength * 2) {
throw new \Exception("problem with r/s combo: " . sizeof($signature) . "/" . $hexlength . " - " . $signature);
}
$r = new MathBigInteger(substr($signature, 0, $hexlength), 16);
$s = new MathBigInteger(substr($signature, $hexlength, $hexlength), 16);
// check rangeconstraints
if ($r->compare(DSAKeyPair::$zero) < 0 || $r->compare($this->key_q) > 0) {
throw new \Exception("problem with r: " . $r->toString());
}
if ($s->compare(DSAKeyPair::$zero) < 0 || $s->compare($this->key_q) > 0) {
throw new \Exception("problem with s: " . $r->toString());
}
return CryptDSA::verify($message, $hash_alg, $r, $s, $this->key_p, $this->key_q, $this->key_g, $this->key_y);
}
/**
* DSA verify
*
* @param string $message message
* @param string $hash_alg hash algorithm
* @param MathBigInteger $r r
* @param MathBigInteger $s s
* @param MathBigInteger $p p
* @param MathBigInteger $q q
* @param MathBigInteger $g g
* @param MathBigInteger $y public key
* @return bool
*/
public static function verify($message, $hash_alg, $r, $s, $p, $q, $g, $y)
{
$hash = new CryptHash($hash_alg);
$hash_m = new MathBigInteger($hash->hash($message), 256);
$w = $s->modInverse($q);
$hash_m_mul = $hash_m->multiply($w);
$u1_base = $hash_m_mul->divide($q);
$u1 = $u1_base[1];
$r_mul = $r->multiply($w);
$u2_base = $r_mul->divide($q);
$u2 = $u2_base[1];
$g_pow = $g->modPow($u1, $p);
$y_pow = $y->modPow($u2, $p);
$g_pow_mul = $g_pow->multiply($y_pow);
$g_pow_mul_mod_base = $g_pow_mul->divide($p);
$g_pow_mul_mod = $g_pow_mul_mod_base[1];
$v_base = $g_pow_mul_mod->divide($q);
$v = $v_base[1];
return $v->compare($r) == 0;
}
