![[golang]使用mTLS双向加密认证http通信](/0.jpg)
前言
假设一个场景，服务端部署在内网，客户端需要通过暴露在公网的nginx与服务端进行通信。为了避免在公网进行 http 明文通信造成的信息泄露，nginx与客户端之间的通信应当使用 https 协议，并且nginx也要验证客户端的身份，也就是mTLS双向加密认证通信。
这条通信链路有三个角色：服务端、Nginx、客户端。
服务端部署在内网，与nginx使用http通信。
客户端在公网，与nginx使用https通信，且双向加密认证。
服务端
服务端只使用http，所以这里用gin框架写个简单的示例，返回客户端一些基本的http信息，比如客户端IP、请求方法、host等。
package main
import (
"log"
"net/http"
"time"
"github.com/gin-gonic/gin"
)
/* 中间件: 获取api处理时长 */
func midElapsed(c *gin.Context) {
start := time.Now()
c.Next()
elapsed := time.Since(start)
log.Printf("API: %s, elapsed: %s", c.Request.URL.Path, elapsed)
}
/* 处理 GET / 请求 */
func f1(c *gin.Context) {
// 获取客户端IP
clientIP := c.ClientIP()
// 获取请求方法
method := c.Request.Method
// 获取协议
proto := c.Request.Proto
// 获取host
host := c.Request.Host
// 请求Path
path := c.Request.URL.Path
log.Printf("客户端IP: %s, 请求方法: %s, 协议: %s, host: %s, path: %s", clientIP, method, proto, host, path)
// 获取请求头
headers := c.Request.Header
for hk, hv := range headers {
log.Printf("header key: %s, value: %s", hk, hv)
}
// 获取名为"mycookie"的cookie
var cookies []string
cookie, err := c.Cookie("mycookie")
if err != nil {
log.Printf("get cookie [mycookie] error: %s", err)
} else {
log.Printf("get cookie [mycookie]: %s", cookie)
cookies = append(cookies, cookie)
}
c.JSON(http.StatusOK, gin.H{
"clientIP": clientIP,
"method": method,
"proto": proto,
"host": host,
"headers": headers,
"cookies": cookies,
"path": path,
})
}
func main() {
r := gin.Default()
r.Use(midElapsed) // 全局引用计算耗时的中间件
r.GET("/", f1)
r.Run("0.0.0.0:8080")
}
生成证书
生成ca根证书。生成过程会要求填写密码、CN、ON、OU等信息，记住密码，填写的信息也要和下一步openssl.cnf文件内容一致。
openssl req -x509 -newkey rsa:4096 -keyout ca.key -out ca.crt -days 3650
新建并编辑文件openssl.cnf文件。req_distinguished_name中内容按需填写，DNS.1要替换成实际域名。
[req]
req_extensions = v3_req
distinguished_name = req_distinguished_name
prompt = no
[req_distinguished_name]
countryName = CN
stateOrProvinceName = Anhui
localityName = Hefei
organizationName = zhangsan
commonName = qw.er.com
[v3_req]
subjectAltName = @alt_names
[alt_names]
DNS.1 = qw.er.com
生成服务端证书
openssl req -newkey rsa:2048 -nodes -keyout server.key -out server.csr -subj "/CN=qw.er.com" -config openssl.cnf
# 提示输入ca私钥的密码
openssl x509 -req -in server.csr -out server.crt -CA ca.crt -CAkey ca.key -CAcreateserial -days 365 -extensions v3_req -extfile openssl.cnf
生成客户端证书
openssl req -newkey rsa:2048 -nodes -keyout client.key -out client.csr -subj "/CN=qw.er.com" -config openssl.cnf
# 提示输入ca私钥的密码
openssl x509 -req -in client.csr -out client.crt -CA ca.crt -CAkey ca.key -CAcreateserial -days 365 -extensions v3_req -extfile openssl.cnf
Nginx配置
nginx反向代理服务端的配置示例如下
server {
listen 80 ssl;
server_name qw.er.com;
ssl_certificate /home/atlas/apps/nginx/certs/qwer/server.crt;
ssl_certificate_key /home/atlas/apps/nginx/certs/qwer/server.key;
# 校验客户端证书
ssl_verify_client on;
ssl_client_certificate /home/atlas/apps/nginx/certs/qwer/ca.crt;
location / {
proxy_set_header Host $host;
proxy_set_header X-real-ip $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_pass http://192.168.0.10:8080; # 服务端地址
}
}
客户端
以下示例使用命令行传参的方式，指定tls证书文件和是否使用tls通信。
package main
import (
"crypto/tls"
"crypto/x509"
"flag"
"io"
"log"
"net/http"
"os"
"time"
)
var (
cafile = flag.String("cafile", "ca.crt", "ca 证书文件")
crtfile = flag.String("crtfile", "client.crt", "客户端tls证书")
keyfile = flag.String("keyfile", "client.key", "客户端tls私钥")
url = flag.String("url", "http://127.0.0.1:8080", "url")
isTls = flag.Bool("tls", false, "是否使用tls")
)
func tlsClient(cafile, crtfile, keyfile string) *http.Transport {
// 加载证书和私钥
clientCert, err := tls.LoadX509KeyPair(crtfile, keyfile)
if err != nil {
log.Fatalf("load key pair error: %s", err)
}
// 加载ca证书
clientCA, err := os.ReadFile(cafile)
if err != nil {
log.Fatalf("load ca cert error: %s", err)
}
// 创建根证书池并添加ca证书
caCertPool := x509.NewCertPool()
caCertPool.AppendCertsFromPEM(clientCA)
// 创建transport
tr := &http.Transport{
TLSClientConfig: &tls.Config{
Certificates: []tls.Certificate{clientCert},
RootCAs: caCertPool,
},
}
return tr
}
func main() {
flag.Parse()
req, err := http.NewRequest("GET", *url, nil)
if err != nil {
log.Fatalf("new request error: %s", err)
}
// 自定义HTTP请求头
req.Header.Set("myheader1", "myheader1value123")
// 自定义一个cookie对象
cookie := &http.Cookie{
Name: "mycookie",
Value: "mycookievalue",
}
req.AddCookie(cookie)
client := &http.Client{
Timeout: time.Second * 5,
}
if *isTls {
client.Transport = tlsClient(*cafile, *crtfile, *keyfile)
}
resp, err := client.Do(req)
if err != nil {
log.Fatalf("get error: %s", err)
}
defer resp.Body.Close()
body, err := io.ReadAll(resp.Body)
if err != nil {
log.Fatalf("read error: %s", err)
}
log.Printf("body: %+v", string(body))
}
Nginx配置
server {
listen 80 ssl;
server_name qw.er.com;
ssl_certificate /home/elifen/apps/nginx/certs/qwer/server.crt;
ssl_certificate_key /home/elifen/apps/nginx/certs/qwer/server.key;
ssl_verify_client on;
ssl_client_certificate /home/elifen/apps/nginx/qwer/ca.crt;
location / {
proxy_set_header Host $host;
proxy_set_header X-real-ip $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_pass http://192.168.0.10:8080;
}
}
测试
这里需要先确保qw.er.com能被正常解析到nginx服务器，比如配置hosts文件或dns解析记录。
go run main.go -cafile ./ca.crt -crtfile ./client.crt -keyfile ./client.key -url 'https://qw.er.com:80/' -tls
输出示例
2023/08/07 17:34:51 body: {"clientIP":"192.168.0.11","cookies":["mycookievalue"],"headers":{"Accept-Encoding":["gzip"],"Connection":["close"],"Cookie":["mycookie=mycookievalue"],"Myheader1":["myheader1value123"],"User-Agent":["Go-http-client/1.1"],"X-Forwarded-For":["192.168.0.11"],"X-Real-Ip":["192.168.0.11"]},"host":"qw.er.com","method":"GET","path":"/","proto":"HTTP/1.0"}