def verify_share_password(uk, shareid, pwd, vcode=''):
    '''验证共享文件的密码.

    如果密码正确, 会在返回的请求头里加入一个cookie: BDCLND
    
    pwd - 四位的明文密码
    vcode - 验证码; 目前还不支持
    '''
    url = ''.join([
        const.PAN_URL,
        'share/verify?&clienttype=0&web=1&channel=chunlei',
        '&shareid=', shareid,
        '&uk=', uk,
    ])
    data = 'pwd={0}&vcode={1}'.format(pwd, vcode)

    req = net.urlopen(url, data=data.encode())
    if req:
        content = req.data.decode()
        info = json.loads(content)
        errno = info.get('errno', 1)
        if errno == 0:
            return req.headers.get_all('Set-Cookie')
        elif errno in (-19, -62, -63):
            pass  # TODO: need verify code
    return None