本篇介绍如何使用golang对微信消息推送进行加解密,后续会补充,目前先写个原理,大概自己看一下,其他的自己应该也能写。老套路,分为三步,为啥写,教程,总结。懒得看的直接看第二步就行。
为什么突然写这个?
由于项目需要,需要用go做一个微服务,一个微信的授权中心,管理所有微信授权。在微信官方文档没有go的demo,本来想着搜一搜别人写的,直接用,一搜全是csdn里的文章,大概看了一下,都是差不多一致的,csdn目前的常态啊,不得不说,乱且不好用,看了看,还是自己来吧,完全跟着官方的demo逻辑,个人感觉自己写的还是挺清晰的,go自己也接触不久,有啥问题的也欢迎指出。
微信消息加解密
大概分为四个文件
wechat_err_code.go
package wechat
var SuccessCode = 0
var ValidateSignatureError = -40001
var ParseXmlError = -40002
var ComputeSignatureError = -40003
var IllegalAesKey = -40004
var ValidateAppidError = -40005
var EncryptAESError = -40006
var DecryptAESError = -40007
var IllegalBuffer = -40008
message.go(消息)
package wechat
import (
"bytes"
"encoding/binary"
"encoding/xml"
"errors"
"strconv"
"time"
)
var EventTicket = "component_verify_ticket" //ticket推送
var EventUnauthorized = "unauthorized" //取消授权
var EventUpdateAuthorized = "updateauthorized" //更新授权
var EventAuthorized = "authorized" //授权成功
var MsgTypeText = "text" //文本消息
var MsgTypeImage = "image" //文本消息
var MsgTypeVoice = "voice" //语音消息
var MsgTypeVideo = "Video" //视频消息
var MsgTypeMusic = "music" //音乐消息
var MsgTypeNews = "news" //图文消息
//EventMessageBody 事件推送
type EventMessageBody struct {
XMLName xml.Name `xml:"xml"`
AppId string `xml:"AppId" json:"app_id"`
CreateTime int `xml:"CreateTime" json:"create_time"`
InfoType string `xml:"InfoType" json:"info_type"`
ComponentVerifyTicket string `xml:"ComponentVerifyTicket" json:"component_verify_ticket"`
AuthorizerAppid string `xml:"AuthorizerAppid" json:"authorizer_appid"`
AuthorizationCode string `xml:"AuthorizationCode" json:"authorization_code"`
AuthorizationCodeExpiredTime string `xml:"AuthorizationCodeExpiredTime" json:"authorization_code_expired_time"`
PreAuthCode string `xml:"PreAuthCode" json:"pre_auth_code"`
}
//MessageBodyDecrypt 消息体
type MessageBodyDecrypt struct {
XMLName xml.Name `xml:"xml"`
ToUserName string `xml:"ToUserName"`
FromUserName string `xml:"FromUserName"`
CreateTime string `xml:"CreateTime"`
MsgType string `xml:"MsgType"`
Url string `xml:"Url"`
PicUrl string `xml:"PicUrl"`
MediaId string `xml:"MediaId"`
ThumbMediaId string `xml:"ThumbMediaId"`
Content string `xml:"Content"`
MsgId int `xml:"MsgId"`
Location_X string `xml:"Location_x"`
Location_Y string `xml:"Location_y"`
Label string `xml:"Label"`
}
type MessageEncryptBody struct {
XMLName xml.Name `xml:"xml"`
Encrypt CDATA `xml:"Encrypt"`
MsgSignature CDATA `xml:"MsgSignature"`
TimeStamp string `xml:"TimeStamp"`
Nonce CDATA `xml:"Nonce"`
}
type MessageText struct {
XMLName xml.Name `xml:"xml"`
ToUserName CDATA `xml:"ToUserName"`
FromUserName CDATA `xml:"FromUserName"`
CreateTime string `xml:"CreateTime"`
MsgType CDATA `xml:"MsgType"`
Content CDATA `xml:"Content"`
}
type MessageImage struct {
XMLName xml.Name `xml:"xml"`
ToUserName CDATA `xml:"ToUserName"`
FromUserName CDATA `xml:"FromUserName"`
CreateTime string `xml:"CreateTime"`
MsgType CDATA `xml:"MsgType"`
Image Media `xml:"Image"`
}
type MessageVoice struct {
XMLName xml.Name `xml:"xml"`
ToUserName CDATA `xml:"ToUserName"`
FromUserName CDATA `xml:"FromUserName"`
CreateTime string `xml:"CreateTime"`
MsgType CDATA `xml:"MsgType"`
Voice Media `xml:"Voice"`
}
type MessageVideo struct {
XMLName xml.Name `xml:"xml"`
ToUserName CDATA `xml:"ToUserName"`
FromUserName CDATA `xml:"FromUserName"`
CreateTime string `xml:"CreateTime"`
MsgType CDATA `xml:"MsgType"`
Video Video `xml:"Video"`
}
type MessageMusic struct {
XMLName xml.Name `xml:"xml"`
ToUserName CDATA `xml:"ToUserName"`
FromUserName CDATA `xml:"FromUserName"`
CreateTime string `xml:"CreateTime"`
MsgType CDATA `xml:"MsgType"`
Music Music `xml:"Music"`
}
type MessageArticle struct {
XMLName xml.Name `xml:"xml"`
ToUserName CDATA `xml:"ToUserName"`
FromUserName CDATA `xml:"FromUserName"`
CreateTime string `xml:"CreateTime"`
MsgType CDATA `xml:"MsgType"`
ArticleCount string `xml:"ArticleCount"`
Articles []ArticleItem `xml:"Articles"`
}
type CDATA struct {
Text string `xml:",innerxml"`
}
type Media struct {
MediaId CDATA `xml:"MediaId"`
}
type Video struct {
MediaId CDATA `xml:"MediaId"`
Title CDATA `xml:"Title"`
Description CDATA `xml:"Description"`
}
type Music struct {
Title CDATA `xml:"Title"`
Description CDATA `xml:"Description"`
MusicUrl CDATA `xml:"MusicUrl"`
HQMusicUrl CDATA `xml:"HQMusicUrl"`
ThumbMediaId CDATA `xml:"ThumbMediaId"`
}
type ArticleItem struct {
Title CDATA `xml:"Title"`
Description CDATA `xml:"Description"`
PicUrl CDATA `xml:"PicUrl"`
Url CDATA `xml:"Url"`
}
func FormatMessage(plainText []byte, data interface{}) (*interface{}, error) {
length := GetMessageLength(plainText)
err := xml.Unmarshal(plainText[20:20+length], data)
if err != nil {
return nil, errors.New("格式化消息失败:format message error")
}
return &data, nil
}
func GetMessageLength(plainText []byte) int32 {
// Read length
buf := bytes.NewBuffer(plainText[16:20])
var length int32
err := binary.Read(buf, binary.BigEndian, &length)
if err != nil {
panic("获取消息长度失败:read message length error")
}
return length
}
func ValueToCDATA(content string) CDATA {
return CDATA{"<![CDATA[" + content + "]]>"}
}
//FormatTextMessage 格式化文本消息
func FormatTextMessage(fromUserName string, toUserName string, content string) []byte {
timestamp := strconv.Itoa(int(time.Now().Unix()))
textMessage := MessageText{FromUserName: ValueToCDATA(fromUserName), ToUserName: ValueToCDATA(toUserName), Content: ValueToCDATA(content), CreateTime: timestamp, MsgType: ValueToCDATA(MsgTypeText)}
messageBytes, err := xml.MarshalIndent(textMessage, " ", " ")
if err != nil {
panic("格式化文本消息失败:xml marsha1 error;" + err.Error())
}
return messageBytes
}
//FormatImageMessage 格式化图片消息
func FormatImageMessage(fromUserName string, toUserName string, mediaId string) []byte {
timestamp := strconv.Itoa(int(time.Now().Unix()))
imageMessage := MessageImage{FromUserName: ValueToCDATA(fromUserName), ToUserName: ValueToCDATA(toUserName), CreateTime: timestamp, MsgType: ValueToCDATA(MsgTypeImage), Image: Media{ValueToCDATA(mediaId)}}
messageBytes, err := xml.MarshalIndent(imageMessage, " ", " ")
if err != nil {
panic("格式化图片消息失败:xml marsha1 error;" + err.Error())
}
return messageBytes
}
//FormatVoiceMessage 格式语音消息
func FormatVoiceMessage(fromUserName string, toUserName string, mediaId string) []byte {
timestamp := strconv.Itoa(int(time.Now().Unix()))
voiceMessage := MessageVoice{FromUserName: ValueToCDATA(fromUserName), ToUserName: ValueToCDATA(toUserName), CreateTime: timestamp, MsgType: ValueToCDATA(MsgTypeVoice), Voice: Media{ValueToCDATA(mediaId)}}
messageBytes, err := xml.MarshalIndent(voiceMessage, " ", " ")
if err != nil {
panic("格式化语音消息失败:xml marsha1 error;" + err.Error())
}
return messageBytes
}
//FormatVideoMessage 格式化视频消息
func FormatVideoMessage(fromUserName string, toUserName string, mediaId string, title string, description string) []byte {
timestamp := strconv.Itoa(int(time.Now().Unix()))
videoMessage := MessageVideo{FromUserName: ValueToCDATA(fromUserName), ToUserName: ValueToCDATA(toUserName), CreateTime: timestamp, MsgType: ValueToCDATA(MsgTypeVideo), Video: Video{
MediaId: ValueToCDATA(mediaId),
Title: ValueToCDATA(title),
Description: ValueToCDATA(description),
}}
messageBytes, err := xml.MarshalIndent(videoMessage, " ", " ")
if err != nil {
panic("格式化语音消息失败:xml marsha1 error;" + err.Error())
}
return messageBytes
}
//FormatMusicMessage 格式化音乐消息
func FormatMusicMessage(fromUserName string, toUserName string, thumbMediaId string, title string, description string, musicUrl string, hQMusicUrl string) []byte {
timestamp := strconv.Itoa(int(time.Now().Unix()))
musicMessage := MessageMusic{FromUserName: ValueToCDATA(fromUserName), ToUserName: ValueToCDATA(toUserName), CreateTime: timestamp, MsgType: ValueToCDATA(MsgTypeMusic), Music: Music{
Title: ValueToCDATA(title),
Description: ValueToCDATA(description),
MusicUrl: ValueToCDATA(musicUrl),
HQMusicUrl: ValueToCDATA(hQMusicUrl),
ThumbMediaId: ValueToCDATA(thumbMediaId),
}}
messageBytes, err := xml.MarshalIndent(musicMessage, " ", " ")
if err != nil {
panic("格式化音乐消息失败:xml marsha1 error;" + err.Error())
}
return messageBytes
}
//FormatArticlesMessage 格式化音乐消息
func FormatArticlesMessage(fromUserName string, toUserName string, items []ArticleItem) []byte {
timestamp := strconv.Itoa(int(time.Now().Unix()))
articleNum := strconv.Itoa(len(items))
musicMessage := MessageArticle{FromUserName: ValueToCDATA(fromUserName), ToUserName: ValueToCDATA(toUserName), CreateTime: timestamp, MsgType: ValueToCDATA(MsgTypeNews), Articles: items, ArticleCount: articleNum}
messageBytes, err := xml.MarshalIndent(musicMessage, " ", " ")
if err != nil {
panic("格式化图文消息失败:xml marsha1 error;" + err.Error())
}
return messageBytes
}
//FormatEncryptData 格式化微信加密数据
func FormatEncryptData(encrypted string, token string) MessageEncryptBody {
nonce := makeRandomString(16)
timestamp := strconv.Itoa(int(time.Now().Unix()))
data := MessageEncryptBody{Encrypt: ValueToCDATA(encrypted), Nonce: ValueToCDATA(nonce), MsgSignature: ValueToCDATA(GetSignature(timestamp, nonce, encrypted, token)), TimeStamp: timestamp}
return data
}
wechat_message.go
package wechat
import (
"bytes"
"encoding/base64"
"encoding/binary"
"encoding/xml"
"errors"
"fmt"
)
type msgCrypt struct {
token string
aesKey string
appid string
}
//EventEncryptRequest 微信事件推送结构体
type EventEncryptRequest struct {
XMLName xml.Name `xml:"xml"`
Encrypt string `xml:"Encrypt"`
Appid string `xml:"Appid"`
}
//MessageEncryptRequest 微信消息加密结构体
type MessageEncryptRequest struct {
XMLName xml.Name `xml:"xml"`
Encrypt string `xml:"Encrypt"`
MsgSignature string `xml:"MsgSignature"`
TimeStamp string `xml:"TimeStamp"`
Nonce string `xml:"Nonce"`
}
//NewWechatMsgCrypt 实例化微信加解密
func NewWechatMsgCrypt(token string, aesKey string, appid string) *msgCrypt {
instance := new(msgCrypt)
instance.token = token
instance.aesKey = aesKey
instance.appid = appid
return instance
}
//WechatEventDecrypt 微信事件推送解密
func (w *msgCrypt) WechatEventDecrypt(eventRequest EventEncryptRequest, msgSignature string, timestamp, nonce string) interface{} {
errCode, data := w.decryptMsg(msgSignature, timestamp, nonce, eventRequest.Encrypt)
if errCode != SuccessCode {
panic(fmt.Sprintf("消息解密失败,code:%d", errCode))
}
message := EventMessageBody{}
_, err := FormatMessage(data, &message)
if err != nil {
panic(fmt.Sprintf("消息格式化失败,%s", err.Error()))
}
return message
}
//WechatMessageDecrypt 微信消息解密
func (w *msgCrypt) WechatMessageDecrypt(messageEncryptRequest MessageEncryptRequest) interface{} {
errCode, data := w.decryptMsg(messageEncryptRequest.MsgSignature, messageEncryptRequest.TimeStamp, messageEncryptRequest.Nonce, messageEncryptRequest.Encrypt)
if errCode != SuccessCode {
panic(fmt.Sprintf("消息解密失败,code:%d", errCode))
}
message := MessageBodyDecrypt{}
_, err := FormatMessage(data, &message)
if err != nil {
panic(fmt.Sprintf("消息格式化失败,%s", err.Error()))
}
return message
}
//WechatTextMessage 微信文本消息加密
func (w *msgCrypt) WechatTextMessage(fromUserName string, toUserName string, content string) MessageEncryptBody {
message := FormatTextMessage(fromUserName, toUserName, content)
encrypted, err := w.encryptMsg(message)
if err != nil {
panic("消息加密失败:" + err.Error())
}
data := FormatEncryptData(encrypted, w.token)
return data
}
//WechatImageMessage 微信图片消息加密
func (w *msgCrypt) WechatImageMessage(fromUserName string, toUserName string, mediaId string) MessageEncryptBody {
message := FormatImageMessage(fromUserName, toUserName, mediaId)
encrypted, err := w.encryptMsg(message)
if err != nil {
panic("消息加密失败:" + err.Error())
}
data := FormatEncryptData(encrypted, w.token)
return data
}
//WechatVoiceMessage 微信语音消息加密
func (w *msgCrypt) WechatVoiceMessage(fromUserName string, toUserName string, mediaId string) MessageEncryptBody {
message := FormatVoiceMessage(fromUserName, toUserName, mediaId)
encrypted, err := w.encryptMsg(message)
if err != nil {
panic("消息加密失败:" + err.Error())
}
data := FormatEncryptData(encrypted, w.token)
return data
}
//WechatVideoMessage 微信视频消息加密
func (w *msgCrypt) WechatVideoMessage(fromUserName string, toUserName string, mediaId string, title string, description string) MessageEncryptBody {
message := FormatVideoMessage(fromUserName, toUserName, mediaId, title, description)
encrypted, err := w.encryptMsg(message)
if err != nil {
panic("消息加密失败:" + err.Error())
}
data := FormatEncryptData(encrypted, w.token)
return data
}
//WechatMusicMessage 微信音乐消息加密
func (w *msgCrypt) WechatMusicMessage(fromUserName string, toUserName string, thumbMediaId string, title string, description string, musicUrl string, hQMusicUrl string) MessageEncryptBody {
message := FormatMusicMessage(fromUserName, toUserName, thumbMediaId, title, description, musicUrl, hQMusicUrl)
encrypted, err := w.encryptMsg(message)
if err != nil {
panic("消息加密失败:" + err.Error())
}
data := FormatEncryptData(encrypted, w.token)
return data
}
//WechatArticlesMessage 微信图文消息加密
func (w *msgCrypt) WechatArticlesMessage(fromUserName string, toUserName string, items []ArticleItem) MessageEncryptBody {
message := FormatArticlesMessage(fromUserName, toUserName, items)
encrypted, err := w.encryptMsg(message)
if err != nil {
panic("消息加密失败:" + err.Error())
}
data := FormatEncryptData(encrypted, w.token)
return data
}
//decryptMsg aes消息解密
func (w *msgCrypt) decryptMsg(msgSignature string, timestamp, nonce string, encrypted string) (int, []byte) {
//验证aes
if len(w.aesKey) != 43 {
return IllegalAesKey, nil
}
//判断签名是否一致
if err := w.validSignature(msgSignature, timestamp, nonce, encrypted); err != nil {
return ValidateSignatureError, nil
}
//解密
prp := NewPrpCrypt(w.aesKey)
plainText, err := prp.decrypt(encrypted)
if err != nil {
return DecryptAESError, nil
}
//验证appid是否一致(消息来源是否一致)
if err := w.validMessageSource(plainText); err != nil {
return ValidateAppidError, nil
}
return SuccessCode, plainText
}
//encryptMsg aes消息加密
func (w *msgCrypt) encryptMsg(message []byte) (string, error) {
//计算消息长度
buf := new(bytes.Buffer)
err := binary.Write(buf, binary.BigEndian, int32(len(message)))
if err != nil {
return "", err
}
messageLength := buf.Bytes()
//生成随机字符串
randBytes := []byte(makeRandomString(16))
plainData := bytes.Join([][]byte{randBytes, messageLength, message, []byte(w.appid)}, nil)
prp := NewPrpCrypt(w.aesKey)
//消息加密
encrypted, err := prp.encrypt(plainData)
if err != nil {
return "", err
}
return base64.StdEncoding.EncodeToString(encrypted), nil
}
//validSignature 验证签名是否一致
func (w *msgCrypt) validSignature(msgSignature string, timestamp, nonce string, encrypted string) error {
validSignature := GetSignature(timestamp, nonce, encrypted, w.token)
if validSignature != msgSignature {
return errors.New("签名不一致:valid sign error")
}
return nil
}
//validMessageSource 验证消息来源
func (w *msgCrypt) validMessageSource(plainText []byte) error {
messageLength := GetMessageLength(plainText)
//获取appid位置
appIdStartPos := 20 + messageLength
id := plainText[appIdStartPos : int(appIdStartPos)+len(w.appid)]
if string(id) != w.appid {
return errors.New("消息来源不一致:Appid is invalid")
}
return nil
}
prpcrypt.go
package wechat
import (
"crypto/aes"
"crypto/cipher"
"crypto/rand"
"encoding/base64"
"io"
)
type prpCrypt struct {
Key []byte
Iv []byte
}
func NewPrpCrypt(aesKey string) *prpCrypt {
instance := new(prpCrypt)
//网络字节序
instance.Key, _ = base64.StdEncoding.DecodeString(aesKey + "=")
instance.Iv = randomIv()
return instance
}
func randomIv() []byte {
iv := make([]byte, aes.BlockSize)
if _, err := io.ReadFull(rand.Reader, iv); err != nil {
panic("random iv error")
}
return iv
}
func (prp *prpCrypt) decrypt(encrypted string) ([]byte, error) {
encryptedBytes, _ := base64.StdEncoding.DecodeString(encrypted)
k := len(prp.Key) //PKCS#7
if len(encryptedBytes)%k != 0 {
panic("ciphertext size is not multiple of aes key length")
}
block, err := aes.NewCipher(prp.Key)
if err != nil {
return nil, err
}
blockMode := cipher.NewCBCDecrypter(block, prp.Iv)
plainText := make([]byte, len(encryptedBytes))
blockMode.CryptBlocks(plainText, encryptedBytes)
return plainText, nil
}
func (prp *prpCrypt) encrypt(plainText []byte) ([]byte, error) {
k := len(prp.Key)
if len(plainText)%k != 0 {
plainText = pKCS7Pad(plainText, k)
}
block, err := aes.NewCipher(prp.Key)
if err != nil {
return nil, err
}
cipherData := make([]byte, len(plainText))
blockMode := cipher.NewCBCEncrypter(block, prp.Iv)
blockMode.CryptBlocks(cipherData, plainText)
return cipherData, nil
}
helpers.go(工具)
package wechat
import (
"bytes"
"crypto/sha1"
"fmt"
"io"
"math/rand"
"sort"
"strings"
)
//GetSignature 获取签名
func GetSignature(timestamp, nonce string, encrypted string, token string) string {
data := []string{
encrypted,
token,
timestamp,
nonce,
}
sort.Strings(data)
s := sha1.New()
_, err := io.WriteString(s, strings.Join(data, ""))
if err != nil {
panic("签名错误:sign error")
}
return fmt.Sprintf("%x", s.Sum(nil))
}
func makeRandomString(length int) string {
randStr := ""
strSource := "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyl"
maxLength := len(strSource) - 1
for i := 0; i < length; i++ {
randomNum := rand.Intn(maxLength)
randStr += strSource[randomNum : randomNum+1]
}
return randStr
}
func pKCS7Pad(plainText []byte, blockSize int) []byte {
// block size must be bigger or equal 2
if blockSize < 1<<1 {
panic("block size is too small (minimum is 2 bytes)")
}
// block size up to 255 requires 1 byte padding
if blockSize < 1<<8 {
// calculate padding length
padLen := padLength(len(plainText), blockSize)
// define PKCS7 padding block
padding := bytes.Repeat([]byte{byte(padLen)}, padLen)
// apply padding
padded := append(plainText, padding...)
return padded
}
// block size bigger or equal 256 is not currently supported
panic("unsupported block size")
}
func padLength(sliceLength, blockSize int) int {
padLen := blockSize - sliceLength%blockSize
if padLen == 0 {
padLen = blockSize
}
return padLen
}
最后加一个demo运行
instance := wechat.NewWechatMsgCrypt("token", "aesKey", "appid")
data := instance.WechatTextMessage("示例内容", "示例内容2", "你好")
fmt.Println("加密结果:", data)
bytes, _ := xml.Marshal(data)
xmlData := wechat.MessageEncryptRequest{}
_ = xml.Unmarshal(bytes, &xmlData)
fmt.Println("解析结果:", xmlData)
fmt.Println("解密结果:", instance.WechatMessageDecrypt(xmlData))
总结
思路还是挺清晰的,大概就这样,没啥特别,这样用起来清晰点,应该不难看懂,有问题再提出来,不想一搜全是那些,看着头疼,这样我还怎么面向百度编程。