附件为将制定的字符串进行Base64加密,然后对加密后的结果通过指定的key和value进行HMAC-SHA1签名,并将签名后的值赋值给sign,例如:encodeparam=Base64(approvestatus=1&channelid=dingding&doctorid=1&doctorname=张三医生&doctortel=13233322323&patientid=12&servertime=201602181454)sign=hmac_sha1(key,encodeparam)