实现消息解密

server/server.go

@@ -0,0 +1,99 @@
+package server
+
+import (
+	"encoding/xml"
+	"fmt"
+	"io/ioutil"
+
+	"github.com/silenceper/wechat/context"
+	"github.com/silenceper/wechat/message"
+	"github.com/silenceper/wechat/util"
+)
+
+//Server struct
+type Server struct {
+	*context.Context
+	isSafeMode bool
+	rawXMLMsg  string
+}
+
+//NewServer init
+func NewServer(context *context.Context) *Server {
+	srv := new(Server)
+	srv.Context = context
+	return srv
+}
+
+//Serve 处理微信的请求消息
+func (srv *Server) Serve() error {
+
+	if !srv.Validate() {
+		return fmt.Errorf("请求校验失败")
+	}
+
+	echostr, exists := srv.GetQuery("echostr")
+	if exists {
+		return srv.String(echostr)
+	}
+
+	srv.handleRequest()
+
+	return nil
+}
+
+//Validate 校验请求是否合法
+func (srv *Server) Validate() bool {
+	timestamp := srv.Query("timestamp")
+	nonce := srv.Query("nonce")
+	signature := srv.Query("signature")
+	return signature == util.Signature(srv.Token, timestamp, nonce)
+}
+
+//HandleRequest 处理微信的请求
+func (srv *Server) handleRequest() {
+	srv.isSafeMode = false
+	encryptType := srv.Query("encrypt_type")
+	if encryptType == "aes" {
+		srv.isSafeMode = true
+	}
+
+	_, err := srv.getMessage()
+	if err != nil {
+		fmt.Printf("%v", err)
+	}
+}
+
+func (srv *Server) getMessage() (interface{}, error) {
+	var rawXMLMsgBytes []byte
+	var err error
+	if srv.isSafeMode {
+		var encryptedXMLMsg message.EncryptedXMLMsg
+		if err := xml.NewDecoder(srv.Request.Body).Decode(&encryptedXMLMsg); err != nil {
+			return nil, fmt.Errorf("从body中解析xml失败,err=%v", err)
+		}
+
+		//验证消息签名
+		timestamp := srv.Query("timestamp")
+		nonce := srv.Query("nonce")
+		msgSignature := srv.Query("msg_signature")
+		msgSignatureCreate := util.Signature(srv.Token, timestamp, nonce, encryptedXMLMsg.EncryptedMsg)
+		if msgSignature != msgSignatureCreate {
+			return nil, fmt.Errorf("消息不合法，验证签名失败")
+		}
+
+		//解密
+		rawXMLMsgBytes, err = util.DecryptMsg(srv.AppID, encryptedXMLMsg.EncryptedMsg, srv.EncodingAESKey)
+		if err != nil {
+			return nil, fmt.Errorf("消息解密失败,err=%v", err)
+		}
+	} else {
+		rawXMLMsgBytes, err = ioutil.ReadAll(srv.Request.Body)
+		if err != nil {
+			return nil, fmt.Errorf("从body中解析xml失败,err=%v", err)
+		}
+	}
+
+	srv.rawXMLMsg = string(rawXMLMsgBytes)
+	fmt.Println(srv.rawXMLMsg)
+	return nil, nil
+}