PHP BigInteger::modPow方法代碼示例

//.........這裏部分代碼省略.........
             // see http://tools.ietf.org/html/rfc3526#section-3
             case 'diffie-hellman-group14-sha1':
                 $prime = 'FFFFFFFFFFFFFFFFC90FDAA22168C234C4C6628B80DC1CD129024E088A67CC74' . '020BBEA63B139B22514A08798E3404DDEF9519B3CD3A431B302B0A6DF25F1437' . '4FE1356D6D51C245E485B576625E7EC6F44C42E9A637ED6B0BFF5CB6F406B7ED' . 'EE386BFB5A899FA5AE9F24117C4B1FE649286651ECE45B3DC2007CB8A163BF05' . '98DA48361C55D39A69163FA8FD24CF5F83655D23DCA3AD961C62F356208552BB' . '9ED529077096966D670C354E4ABC9804F1746C08CA18217C32905E462E36CE3B' . 'E39E772C180E86039B2783A2EC07A28FB5C55DF06F4C52C9DE2BCBF695581718' . '3995497CEA956AE515D2261898FA051015728E5A8AACAA68FFFFFFFFFFFFFFFF';
                 break;
         }
         // For both diffie-hellman-group1-sha1 and diffie-hellman-group14-sha1
         // the generator field element is 2 (decimal) and the hash function is sha1.
         $g = new BigInteger(2);
         $prime = new BigInteger($prime, 16);
         $exchange_hash_rfc4419 = '';
         $clientKexInitMessage = NET_SSH2_MSG_KEXDH_INIT;
         $serverKexReplyMessage = NET_SSH2_MSG_KEXDH_REPLY;
     }
     switch ($kex_algorithm) {
         case 'diffie-hellman-group-exchange-sha256':
             $kexHash = new Hash('sha256');
             break;
         default:
             $kexHash = new Hash('sha1');
     }
     /* To increase the speed of the key exchange, both client and server may
                reduce the size of their private exponents.  It should be at least
                twice as long as the key material that is generated from the shared
                secret.  For more details, see the paper by van Oorschot and Wiener
                [VAN-OORSCHOT].
     
                -- http://tools.ietf.org/html/rfc4419#section-6.2 */
     $one = new BigInteger(1);
     $keyLength = min($keyLength, $kexHash->getLength());
     $max = $one->bitwise_leftShift(16 * $keyLength);
     // 2 * 8 * $keyLength
     $max = $max->subtract($one);
     $x = $one->random($one, $max);
     $e = $g->modPow($x, $prime);
     $eBytes = $e->toBytes(true);
     $data = pack('CNa*', $clientKexInitMessage, strlen($eBytes), $eBytes);
     if (!$this->_send_binary_packet($data)) {
         user_error('Connection closed by server');
         return false;
     }
     $response = $this->_get_binary_packet();
     if ($response === false) {
         user_error('Connection closed by server');
         return false;
     }
     extract(unpack('Ctype', $this->_string_shift($response, 1)));
     if ($type != $serverKexReplyMessage) {
         user_error('Expected SSH_MSG_KEXDH_REPLY');
         return false;
     }
     $temp = unpack('Nlength', $this->_string_shift($response, 4));
     $this->server_public_host_key = $server_public_host_key = $this->_string_shift($response, $temp['length']);
     $temp = unpack('Nlength', $this->_string_shift($server_public_host_key, 4));
     $public_key_format = $this->_string_shift($server_public_host_key, $temp['length']);
     $temp = unpack('Nlength', $this->_string_shift($response, 4));
     $fBytes = $this->_string_shift($response, $temp['length']);
     $f = new BigInteger($fBytes, -256);
     $temp = unpack('Nlength', $this->_string_shift($response, 4));
     $this->signature = $this->_string_shift($response, $temp['length']);
     $temp = unpack('Nlength', $this->_string_shift($this->signature, 4));
     $this->signature_format = $this->_string_shift($this->signature, $temp['length']);
     $key = $f->modPow($x, $prime);
     $keyBytes = $key->toBytes(true);
     $this->exchange_hash = pack('Na*Na*Na*Na*Na*a*Na*Na*Na*', strlen($this->identifier), $this->identifier, strlen($this->server_identifier), $this->server_identifier, strlen($kexinit_payload_client), $kexinit_payload_client, strlen($kexinit_payload_server), $kexinit_payload_server, strlen($this->server_public_host_key), $this->server_public_host_key, $exchange_hash_rfc4419, strlen($eBytes), $eBytes, strlen($fBytes), $fBytes, strlen($keyBytes), $keyBytes);
     $this->exchange_hash = $kexHash->hash($this->exchange_hash);
     if ($this->session_id === false) {

 /**
  * DSA verify.
  *
  * @param string $message            Message.
  * @param string $hash_alg           Hash algorithm.
  * @param \phpseclib\Math\BigInteger $r  r.
  * @param \phpseclib\Math\BigInteger $s  s.
  *
  * @return bool  True if verified.
  */
 public function verify($message, $hash_alg, $r, $s)
 {
     $hash = new Crypt\Hash($hash_alg);
     $hash_m = new BigInteger($hash->hash($message), 256);
     $g = new BigInteger($this->_key->key['g'], 256);
     $p = new BigInteger($this->_key->key['p'], 256);
     $q = new BigInteger($this->_key->key['q'], 256);
     $y = new BigInteger($this->_key->key['y'], 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;
 }

 /**
  * Performs RSA Blinding
  *
  * Protects against timing attacks by employing RSA Blinding.
  * Returns $x->modPow($this->exponents[$i], $this->primes[$i])
  *
  * @access private
  * @param BigInteger $x        	
  * @param BigInteger $r        	
  * @param Integer $i        	
  * @return BigInteger
  */
 function _blind($x, $r, $i)
 {
     $x = $x->multiply($r->modPow($this->publicExponent, $this->primes[$i]));
     $x = $x->modPow($this->exponents[$i], $this->primes[$i]);
     $r = $r->modInverse($this->primes[$i]);
     $x = $x->multiply($r);
     list(, $x) = $x->divide($this->primes[$i]);
     return $x;
 }

 /**
  * Decrypt data.
  *
  * @param string $text  PKCS1-v1_5 encoded text.
  *
  * @return string  Plaintext.
  */
 public function decrypt($text)
 {
     $out = '';
     $p_len = strlen($this->_key->key['p']);
     $text = str_split($text, $p_len);
     $text[count($text) - 1] = str_pad($text[count($text) - 1], $p_len, chr(0), STR_PAD_LEFT);
     $p = new BigInteger($this->_key->key['p'], 256);
     $x = new BigInteger($this->_key->key['x'], 256);
     for ($i = 0, $j = count($text); $i < $j; $i += 2) {
         $c1 = new BigInteger($text[$i], 256);
         $c2 = new BigInteger($text[$i + 1], 256);
         $s = $c1->modPow($x, $p);
         $m_prime = $s->modInverse($p)->multiply($c2)->divide($p);
         $em = str_pad($m_prime[1]->toBytes(), $p_len, chr(0), STR_PAD_LEFT);
         // EME-PKCS1-v1_5 decoding
         if (ord($em[0]) !== 0 || ord($em[1]) !== 2) {
             throw new RuntimeException();
         }
         $out .= substr($em, strpos($em, chr(0), 2) + 1);
     }
     return $out;
 }