light-apiengine/third/wx/verify.go

package wx

import (
	"crypto/md5"
	"encoding/hex"
	"encoding/xml"
	"errors"
	"io"
	"net/url"
	"sort"
	"strings"
)

type XMLMap url.Values

type xmlMapEntry struct {
	XMLName xml.Name
	Value   string `xml:",chardata"`
}

func (m XMLMap) UnmarshalXML(d *xml.Decoder, start xml.StartElement) error {
	for {
		var e xmlMapEntry
		err := d.Decode(&e)
		if err == io.EOF {
			break
		} else if err != nil {
			return err
		}
		(m)[e.XMLName.Local] = []string{e.Value}
	}
	return nil
}

func (v XMLMap) Get(key string) string {
	if v == nil {
		return ""
	}
	vs := v[key]
	if len(vs) == 0 {
		return ""
	}
	return vs[0]
}

func (v XMLMap) Set(key, value string) {
	v[key] = []string{value}
}

func (v XMLMap) Add(key, value string) {
	v[key] = append(v[key], value)
}

func (v XMLMap) Del(key string) {
	delete(v, key)
}

func VerifyResponseData(data []byte, key string) (ok bool, err error) {
	var param = make(XMLMap)
	err = xml.Unmarshal(data, &param)
	if err != nil {
		return false, err
	}

	return VerifyResponseValues(url.Values(param), key)
}

func VerifyResponseValues(param url.Values, key string) (bool, error) {
	// 验证签名
	var sign = param.Get("sign")
	delete(param, "sign")
	if sign == "" {
		return false, errors.New("签名验证失败")
	}

	var sign2 = SignMD5(param, key)
	if sign == sign2 {
		return true, nil
	}
	return false, errors.New("签名验证失败")
}

func SignMD5(param url.Values, key string) (sign string) {
	var pList = make([]string, 0, 0)
	for key := range param {
		var value = param.Get(key)
		if len(value) > 0 {
			pList = append(pList, key+"="+value)
		}
	}
	sort.Strings(pList)
	if key != "" {
		pList = append(pList, "key="+key)
	}

	var src = strings.Join(pList, "&")
	md5Ctx := md5.New()
	md5Ctx.Write([]byte(src))
	cipherStr := md5Ctx.Sum(nil)

	sign = strings.ToUpper(hex.EncodeToString(cipherStr))
	return sign
}