Fix basic authentication for browsers (#3)

CHANGELOG.md

@@ -5,9 +5,12 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 Versioning](https://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased]
+### Fixed
+- Fixed issue with incorrect headers and response code for browser/system level proxy settings
+([#1](https://github.com/jthomperoo/simple-proxy/issues/1)).
 
 ## [v1.1.0] - 2022-04-08
-## Added
+### Added
 - Basic auth support, can provide `--basic-auth 'username:password'` which the proxy then checks for valid auth
 provided in the `Proxy-Authentication` header.
 - Can choose if auth should be logged with the `--log-auth` option.

README.md

@@ -98,6 +98,23 @@ Usage of simple-proxy:
     	comma-separated list of pattern=N settings for file-filtered logging
 ```
 
+## Checking the proxy is working
+
+You can use [cURL](https://curl.se/) on Linux/MacOS systems to check if your proxy is working:
+
+```bash
+curl --proxy 'http://localhost:8888' 'https://www.random.org/integers/?num=1&min=1&max=5&col=1&base=10&format=plain&rnd=new'
+```
+
+This will reach out to [random.org](https://www.random.org) to fetch a random number, using the default proxy address
+and port.
+
+On Windows you can use:
+
+```powershell
+curl.exe 'https://www.random.org/integers/?num=1&min=1&max=5&col=1&base=10&format=plain&rnd=new' --proxy 'http://localhost:8888'
+```
+
 ## Contributing
 
 See the [CONTRIBUTING](./CONTRIBUTING.md) and [CODE OF CONDUCT](./CODE_OF_CONDUCT.md) documents.

proxy/proxy.go

@@ -42,7 +42,8 @@ func (p *ProxyHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 			} else {
 				glog.Errorln("Unauthorized")
 			}
-			http.Error(w, "Unauthorized", http.StatusUnauthorized)
+			w.Header().Set("Proxy-Authenticate", "Basic")
+			http.Error(w, "Unauthorized", http.StatusProxyAuthRequired)
 			return
 		}
 	}