2023

(macos, self-signed cert, https, ssl, tls, localhost, nginx, app server)

Create a fake backend:

mkdir <project-dir>  
cd <project-dir>  
echo "hello world" >> index.html  
python -m http.server  
:: visit http://localhost:8000 and verify I see "hello world"  

Create a self-signed TLS certificate:

openssl genrsa 4096 -out localhost.key  
openssl req -new -x509 -subj "/CN=localhost/" -addext "subjectAltName = DNS:localhost" -nodes -sha256 -key localhost.key -out localhost.pem  

Chrome and safari enforce TLS certs contain a subjectAltName.
Verify there is a section called “X509v3 extensions”, and that it contains “subjectAltName”:

openssl x509 -noout -text -in localhost.pem  

Tranform the cert for MacOS Keychain:

openssl x509 -in localhost.pem -inform pem -outform der -out localhost.cer  

Trust the cert in keychain:

sudo security add-trusted-cert -d -r trustRoot -k /Library/Keychains/System.keychain localhost.cer  
:: Open Keychain Access > System and double tap 'localhost'  
:: Tap the 'Trust' chevron and verify that SSL is set to "Always Trust"  

Install nginx

brew install nginx  

Add /opt/homebrew/etc/nginx/servers/localhost.conf with the contents (replace /path/to/<project-dir>):

upstream app-server {  
  server 127.0.0.1:8000;  
}  

server {  
    listen       443 ssl;  
    server_name  localhost;  

    ssl_certificate      /path/to/<project-dir>/localhost.pem;  
    ssl_certificate_key  /path/to/<project-dir>/localhost.key;  

    ssl_session_cache    shared:SSL:1m;  
    ssl_session_timeout  5m;  

    ssl_ciphers  HIGH:!aNULL:!MD5;  
    ssl_prefer_server_ciphers  on;  

    location / {  
      proxy_set_header X-Real-IP $remote_addr;  
      proxy_set_header X_FORWARDED_PROTO https;  
      proxy_set_header X_FORWARDED_HOST $http_host;  
      proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;  
      proxy_redirect off;  
      proxy_max_temp_file_size 0;  

      if (!-f $request_filename) {  
          proxy_pass http://app-server;  
          break;  
      }  
   }  
}  

Start nginx:

nginx  

Browse in Chrome or Safari to https://localhost (Firefox doesn’t trust self signed certs)

Stop nginx:

nginx -s stop