golang实现openssl自签名双向认证

第一步：生成CA、服务端、客户端证书

1. 生成CA根证书

生成CA证书私钥

openssl genrsa -out ca.key 4096

创建ca.conf 文件

[ req ]
default_bits       = 4096
distinguished_name = req_distinguished_name

[ req_distinguished_name ]
countryName                 = Country Name (2 letter code)
countryName_default         = CN
stateOrProvinceName         = State or Province Name (full name)
stateOrProvinceName_default = JiangSu
localityName                = Locality Name (eg, city)
localityName_default        = NanJing
organizationName            = Organization Name (eg, company)
organizationName_default    = Sheld
commonName                  = Common Name (e.g. server FQDN or YOUR name)
commonName_max              = 64
commonName_default          = localhost

生成根证书签发申请文件(csr文件)

openssl req \
  -new \
  -sha256 \
  -out ca.csr \
  -key ca.key \
  -config ca.conf

生成自签发根证书(crt文件)

openssl x509 \
    -req \
    -days 3650 \
    -in ca.csr \
    -signkey ca.key \
    -out ca.pem

2. 生成服务端证书

生成服务端私钥

openssl genrsa -out server.key 2048

创建 server.conf 文件

[ req ]
default_bits       = 2048
distinguished_name = req_distinguished_name
req_extensions     = req_ext

[ req_distinguished_name ]
countryName                 = Country Name (2 letter code)
countryName_default         = CN
stateOrProvinceName         = State or Province Name (full name)
stateOrProvinceName_default = JiangSu
localityName                = Locality Name (eg, city)
localityName_default        = NanJing
organizationName            = Organization Name (eg, company)
organizationName_default    = Sheld
commonName                  = Common Name (e.g. server FQDN or YOUR name)
commonName_max              = 64
commonName_default          = localhost    # 此处尤为重要，需要用该服务名字填写到客户端的代码中

[ req_ext ]
subjectAltName = @alt_names

[alt_names]
DNS.1   = localhost
IP.1      = 127.0.0.1

生成服务端签发申请文件(csr文件)

openssl req \
  -new \
  -sha256 \
  -out server.csr \
  -key server.key \
  -config server.conf

使用CA证书签署服务器证书

openssl x509 \
  -req \
  -days 3650 \
  -CA ca.pem \
  -CAkey ca.key \
  -CAcreateserial \
  -in server.csr \
  -out server.pem \
  -extensions req_ext \
  -extfile server.conf

3. 生成客户端证书

生成客户端私钥

openssl genrsa -out client.key 2048

创建 client.conf 文件

[ req ]
default_bits       = 2048
distinguished_name = req_distinguished_name

[ req_distinguished_name ]
countryName                 = Country Name (2 letter code)
countryName_default         = CN
stateOrProvinceName         = State or Province Name (full name)
stateOrProvinceName_default = JiangSu
localityName                = Locality Name (eg, city)
localityName_default        = NanJing
organizationName            = Organization Name (eg, company)
organizationName_default    = Sheld
commonName                  = Common Name (e.g. server FQDN or YOUR name)
commonName_max              = 64
commonName_default          = localhost

生成客户端端签发申请文件(csr文件)

openssl req \
  -new \
  -sha256 \
  -out client.csr \
  -key client.key \
  -config client.conf

使用CA证书签署客户端器证书

openssl x509 \
    -req \
    -days 3650 \
    -CA ca.pem \
    -CAkey ca.key \
    -CAcreateserial \
    -in client.csr \
    -out client.pem

第二步：golang 服务端、客户端代码编写

1. 项目目录结构

在这里插入图片描述

2. 服务端代码：server.go

package main

import (
	"crypto/tls"
	"crypto/x509"
	"fmt"
	"net/http"
	"os"
)

type MyHandler struct {
}

func (h *MyHandler) ServeHTTP(w http.ResponseWriter,
	r *http.Request) {
	fmt.Fprint(w, "Hello, HTTPS!")
}

func main() {
	pool := x509.NewCertPool() // 创建证书池

	caCertPath := "./cert/ca.pem"
	caCrt, err := os.ReadFile(caCertPath) // 读取本地CA证书文件
	if err != nil {
		fmt.Println("ReadFile err:", err)
		return
	}

	pool.AppendCertsFromPEM(caCrt) // 将证书添加到证书池中

	s := &http.Server{ // 创建 HTTP服务器实例，并设置服务器的监听地址（本例中是127.0.0.1:8088）、处理器（即上面定义的myhandler结构体）、以及TLS配置。
		Addr:    "127.0.0.1:8088",
		Handler: &MyHandler{},
		TLSConfig: &tls.Config{
			ClientCAs:  pool,                           // 指定客户端需要验证的CA证书池（即上面创建的pool）
			ClientAuth: tls.RequireAndVerifyClientCert, // 要求客户端在发送请求时必须携带证书
		},
	}

	err = s.ListenAndServeTLS("./cert/server.pem", "./cert/server.key")
	if err != nil {
		fmt.Println("ListenAndServeTLS err:", err)
	}
}

3. 客户端代码：client.go

package main

import (
	"crypto/tls"
	"crypto/x509"
	"fmt"
	"io"
	"net/http"
	"os"
)

func main() {
	pool := x509.NewCertPool()    // 创建 x509.CertPool，用于存储CA证书
	caCertPath := "./cert/ca.pem" // 从文件中读取CA证书的内容
	caCrt, err := os.ReadFile(caCertPath)
	if err != nil {
		fmt.Println("ReadFile err:", err)
		return
	}
	pool.AppendCertsFromPEM(caCrt)                                               // 将CA证书添加到CertPool中
	cliCrt, err := tls.LoadX509KeyPair("./cert/client.pem", "./cert/client.key") //加载客户端证书和私钥
	if err != nil {
		fmt.Println("Loadx509keypair err:", err)
		return
	}
	tr := &http.Transport{ // 创建一个http.Transport，并配置TLS相关信息
		TLSClientConfig: &tls.Config{
			RootCAs:      pool,                      // 设置根证书池
			Certificates: []tls.Certificate{cliCrt}, // 设置客户端证书和私钥
		},
	}
	client := &http.Client{Transport: tr}             // 创建一个http.Client，并设置Transport为上面创建的Transport对象
	resp, err := client.Get("https://127.0.0.1:8088") // 使用创建的Client发送GET请求
	if err != nil {
		fmt.Println("Http Get error:", err)
		return
	}
	defer resp.Body.Close()
	body, err := io.ReadAll(resp.Body) // 读取并打印响应体的内容
	fmt.Println(string(body))
}