首先通过下面的链接下载openSSL
https://slproweb.com/products...

下载完毕后，执行openssl进入交互式界面：

使用命令生成privatekey.pem 1024意思是1024位长度。

openssl genrsa -out privatekey.pem 1024

生成的privatekey.pem，打开看一看长啥样：

什么是pem文件？

.pem - Defined in RFCs 1421 through 1424, this is a container format that may include just the public certificate (such as with Apache installs, and CA certificate files /etc/ssl/certs), or may include an entire certificate chain including public key, private key, and root certificates. Confusingly, it may also encode a CSR (e.g. as used here) as the PKCS10 format can be translated into PEM. The name is from Privacy Enhanced Mail (PEM), a failed method for secure email but the container format it used lives on, and is a base64 translation of the x509 ASN.1 keys.

简单的说，就是一个密钥文件。

第二步，基于第一步生成的密钥文件生成一个证书请求：
openssl req -new -key privatekey.pem -out certrequest.csr

如果懒得维护证书明细，直接敲回车，会自动填入默认值：

最后基于第一步生成的密钥和证书请求生成一个数字证书：当然颁发机构就是自己了，仅用于测试目的。
openssl x509 -req -in certrequest.csr -signkey privatekey.pem -out certificate.pem

至此我们有了privatekey.pem和Certificate.pem两个证书了。

下面是我https服务器的代码，很简单，只有50几行：

var app = require('express')();var fs    = require('fs');var https = require('https');var httpOptions =  { key: fs.readFileSync("keys/privatekey.pem"), cert: fs.readFileSync("keys/certificate.pem")}var server = https.createServer(httpOptions, app);var io = require('socket.io')(server);console.log("https server listens on port 8080...");server.listen(8080);function print_env(){  console.log(process.env);}app.get('/', function (req, res) {  var response = "Hello World";  res.send(response);});app.get('/env', function (req, res) {  print_env();  // res.sendFile(__dirname + '/index.html');  var response = JSON.stringify(process.env);  res.send(response);});app.get('/redis', function (req, res) {  var redisClient = require("./redisClient");    function callback(response){    // var response = "ok";//JSON.stringify(process.env);    res.send(response);  }  redisClient.test(callback);});io.on('connection', function (socket) {  console.log("connect comming from client: " + socket.id);  socket.emit('messages_jerry', { hello: 'world greeting from Server!' });  socket.on('messages', function (data) {    console.log("data received from Client:" + JSON.stringify(data,2,2));  });});

从代码里不难理解这两个pem文件是如何用在https服务器里的。
最后在浏览器里测试。因为是自己颁发的证书，没有经过CA验证，所以浏览器会显示一个警告。

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