悬赏现金50！！！将PHP的mcrypt_generic转化为golang，求将下面的翻译为golang

Question

 <?php
class CryptAES {
    protected $cipher = MCRYPT_RIJNDAEL_128;
    protected $mode = MCRYPT_MODE_ECB;
    protected $pad_method = NULL;
    protected $secret_key = '';
    protected $iv = '';

    public function set_cipher($cipher) {
        $this->cipher = $cipher;
    }

    public function set_mode($mode) {
        $this->mode = $mode;
    }

    public function set_iv($iv) {
        $this->iv = $iv;
    }

    public function set_key($key) {
        $this->secret_key = $key;
    }

    public function require_pkcs5() {
        $this->pad_method = 'pkcs5';
    }

    protected function pad_or_unpad($str, $ext) {
        if (is_null($this->pad_method)) {
            return $str;
        } else {
            $func_name = __CLASS__ . '::' . $this->pad_method . '_' . $ext . 'pad';
            if (is_callable($func_name)) {
                $size = mcrypt_get_block_size($this->cipher, $this->mode);
                return call_user_func($func_name, $str, $size);
            }
        }
        return $str;
    }

    protected function pad($str) {
        return $this->pad_or_unpad($str, '');
    }

    protected function unpad($str) {
        return $this->pad_or_unpad($str, 'un');
    }

    public function encrypt($str) {
        $str = $this->pad($str);
        $td = mcrypt_module_open($this->cipher, '', $this->mode, '');

        if (empty($this->iv)) {
            $iv = @mcrypt_create_iv(mcrypt_enc_get_iv_size($td), MCRYPT_RAND);
        } else {
            $iv = $this->iv;
        }

        mcrypt_generic_init($td, hex2bin($this->secret_key), $iv);
        $cyper_text = mcrypt_generic($td, $str);
        $rt = strtoupper(bin2hex($cyper_text));
        mcrypt_generic_deinit($td);
        mcrypt_module_close($td);

        return $rt;
    }

    public function decrypt($str) {
        $td = mcrypt_module_open($this->cipher, '', $this->mode, '');

        if (empty($this->iv)) {
            $iv = @mcrypt_create_iv(mcrypt_enc_get_iv_size($td), MCRYPT_RAND);
        } else {
            $iv = $this->iv;
        }

        mcrypt_generic_init($td, $this->secret_key, $iv);
        //$decrypted_text = mdecrypt_generic($td, self::hex2bin($str));
        $decrypted_text = mdecrypt_generic($td, base64_decode($str));
        $rt = $decrypted_text;
        mcrypt_generic_deinit($td);
        mcrypt_module_close($td);

        return $this->unpad($rt);
    }

    public static function hex2bin($hexdata) {
        $bindata = '';
        $length = strlen($hexdata);
        for ($i = 0; $i < $length; $i += 2) {
            $bindata .= chr(hexdec(substr($hexdata, $i, 2)));
        }
        return $bindata;
    }

    public static function pkcs5_pad($text, $blocksize) {
        $pad = $blocksize - (strlen($text) % $blocksize);
        return $text . str_repeat(chr($pad), $pad);
    }

    public static function pkcs5_unpad($text) {
        $pad = ord($text{strlen($text) - 1});
        if ($pad > strlen($text)) {
            return false;
        }

        if (strspn($text, chr($pad), strlen($text) - $pad) != $pad) {
            return false;
        }

        return substr($text, 0, -1 * $pad);
    }
}

$keyStr = '6D6A39C7078F6783E561B0D1A9EB2E68';
$plainText = 'test';

$aes = new CryptAES();
$aes->set_key($keyStr);
$aes->require_pkcs5();
$encText = $aes->encrypt($plainText);

echo $encText;

?>

Answer 1

<?php
class CryptAES {
protected $cipher = MCRYPT_RIJNDAEL_128;
protected $mode = MCRYPT_MODE_ECB;
protected $pad_method = NULL;
protected $secret_key = '';
protected $iv = '';

public function set_cipher($cipher) {
    $this->cipher = $cipher;
}

public function set_mode($mode) {
    $this->mode = $mode;
}

public function set_iv($iv) {
    $this->iv = $iv;
}

public function set_key($key) {
    $this->secret_key = $key;
}

public function require_pkcs5() {
    $this->pad_method = 'pkcs5';
}

protected function pad_or_unpad($str, $ext) {
    if (is_null($this->pad_method)) {
        return $str;
    } else {
        $func_name = __CLASS__ . '::' . $this->pad_method . '_' . $ext . 'pad';
        if (is_callable($func_name)) {
            $size = mcrypt_get_block_size($this->cipher, $this->mode);
            return call_user_func($func_name, $str, $size);
        }
    }
    return $str;
}

protected function pad($str) {
    return $this->pad_or_unpad($str, '');
}

protected function unpad($str) {
    return $this->pad_or_unpad($str, 'un');
}

public function encrypt($str) {
    $str = $this->pad($str);
    $td = mcrypt_module_open($this->cipher, '', $this->mode, '');

    if (empty($this->iv)) {
        $iv = @mcrypt_create_iv(mcrypt_enc_get_iv_size($td), MCRYPT_RAND);
    } else {
        $iv = $this->iv;
    }

    mcrypt_generic_init($td, hex2bin($this->secret_key), $iv);
    $cyper_text = mcrypt_generic($td, $str);
    $rt = strtoupper(bin2hex($cyper_text));
    mcrypt_generic_deinit($td);
    mcrypt_module_close($td);

    return $rt;
}

public function decrypt($str) {
    $td = mcrypt_module_open($this->cipher, '', $this->mode, '');

    if (empty($this->iv)) {
        $iv = @mcrypt_create_iv(mcrypt_enc_get_iv_size($td), MCRYPT_RAND);
    } else {
        $iv = $this->iv;
    }

    mcrypt_generic_init($td, $this->secret_key, $iv);
    //$decrypted_text = mdecrypt_generic($td, self::hex2bin($str));
    $decrypted_text = mdecrypt_generic($td, base64_decode($str));
    $rt = $decrypted_text;
    mcrypt_generic_deinit($td);
    mcrypt_module_close($td);

    return $this->unpad($rt);
}

public static function hex2bin($hexdata) {
    $bindata = '';
    $length = strlen($hexdata);
    for ($i = 0; $i < $length; $i += 2) {
        $bindata .= chr(hexdec(substr($hexdata, $i, 2)));
    }
    return $bindata;
}

public static function pkcs5_pad($text, $blocksize) {
    $pad = $blocksize - (strlen($text) % $blocksize);
    return $text . str_repeat(chr($pad), $pad);
}

public static function pkcs5_unpad($text) {
    $pad = ord($text{strlen($text) - 1});
    if ($pad > strlen($text)) {
        return false;
    }

    if (strspn($text, chr($pad), strlen($text) - $pad) != $pad) {
        return false;
    }

    return substr($text, 0, -1 * $pad);
}

}

$keyStr = '6D6A39C7078F6783E561B0D1A9EB2E68';
$plainText = 'test';

$aes = new CryptAES();
$aes->set_key($keyStr);
$aes->require_pkcs5();
$encText = $aes->encrypt($plainText);

echo $encText;

?>