phpseclib\Crypt\Twofish::setKey PHP Method

    function setKey($key)
    {
        switch (strlen($key)) {
            case 16:
            case 24:
            case 32:
                break;
            default:
                throw new \LengthException('Key of size ' . strlen($key) . ' not supported by this algorithm. Only keys of sizes 16, 24 or 32 supported');
        }
        parent::setKey($key);
    }

 public function testVectors()
 {
     $engines = array(Base::ENGINE_INTERNAL => 'internal', Base::ENGINE_MCRYPT => 'mcrypt', Base::ENGINE_OPENSSL => 'OpenSSL');
     foreach ($engines as $engine => $name) {
         $tf = new Twofish();
         $tf->disablePadding();
         // tests from https://www.schneier.com/code/ecb_ival.txt
         // key size = 128
         $key = pack('H*', '00000000000000000000000000000000');
         $tf->setKey($key);
         if (!$tf->isValidEngine($engine)) {
             self::markTestSkipped('Unable to initialize ' . $name . ' engine');
         }
         $plaintext = pack('H*', '00000000000000000000000000000000');
         $ciphertext = $tf->encrypt($plaintext);
         $expected = strtolower('9F589F5CF6122C32B6BFEC2F2AE8C35A');
         $this->assertEquals(bin2hex($ciphertext), $expected, "Failed asserting that {$plaintext} yielded expected output in {$name} engine");
         $expected = bin2hex($plaintext);
         $plaintext = bin2hex($tf->decrypt($ciphertext));
         $this->assertEquals($plaintext, $expected, "Failed asserting that {$plaintext} yielded expected output in {$name} engine");
         // key size = 192
         $key = pack('H*', '0123456789ABCDEFFEDCBA98765432100011223344556677');
         $tf->setKey($key);
         if (!$tf->isValidEngine($engine)) {
             self::markTestSkipped('Unable to initialize ' . $name . ' engine');
         }
         $plaintext = pack('H*', '00000000000000000000000000000000');
         $ciphertext = $tf->encrypt($plaintext);
         $expected = strtolower('CFD1D2E5A9BE9CDF501F13B892BD2248');
         $this->assertEquals(bin2hex($ciphertext), $expected, "Failed asserting that {$plaintext} yielded expected output in {$name} engine");
         $expected = bin2hex($plaintext);
         $plaintext = bin2hex($tf->decrypt($ciphertext));
         $this->assertEquals($plaintext, $expected, "Failed asserting that {$plaintext} yielded expected output in {$name} engine");
         // key size = 256
         $key = pack('H*', '0123456789ABCDEFFEDCBA987654321000112233445566778899AABBCCDDEEFF');
         $tf->setKey($key);
         if (!$tf->isValidEngine($engine)) {
             self::markTestSkipped('Unable to initialize ' . $name . ' engine');
         }
         $plaintext = pack('H*', '00000000000000000000000000000000');
         $ciphertext = $tf->encrypt($plaintext);
         $expected = strtolower('37527BE0052334B89F0CFCCAE87CFA20');
         $this->assertEquals(bin2hex($ciphertext), $expected, "Failed asserting that {$plaintext} yielded expected output in {$name} engine");
         $expected = bin2hex($plaintext);
         $plaintext = bin2hex($tf->decrypt($ciphertext));
         $this->assertEquals($plaintext, $expected, "Failed asserting that {$plaintext} yielded expected output in {$name} engine");
     }
 }