google_auth_proxy ================= A reverse proxy that provides authentication using Google OAuth2 to validate individual accounts, or a whole google apps domain. [![Build Status](https://secure.travis-ci.org/bitly/google_auth_proxy.png?branch=master)](http://travis-ci.org/bitly/google_auth_proxy) ![sign_in_page](https://cloud.githubusercontent.com/assets/45028/4970624/7feb7dd8-6886-11e4-93e0-c9904af44ea8.png) ## Architecture ``` _______ ___________________ __________ |Nginx| ----> |google_auth_proxy| ----> |upstream| ------- ------------------- ---------- || \/ [google oauth2 api] ``` ## Installation 1. Download [Prebuilt Binary](https://github.com/bitly/google_auth_proxy/releases) or build from `master` with `$ go get github.com/bitly/google_auth_proxy` which should put the binary in `$GOROOT/bin` 2. Register an OAuth Application with Google 3. Configure Google Auth Proxy using config file, command line options, or environment variables 4. Deploy behind a SSL endpoint (example provided for Nginx) ## OAuth Configuration You will need to register an OAuth application with google, and configure it with Redirect URI(s) for the domain you intend to run `google_auth_proxy` on. 1. Create a new project: https://console.developers.google.com/project 2. Under "APIs & Auth", choose "Credentials" 3. Now, choose "Create new Client ID" * The Application Type should be **Web application** * Enter your domain in the Authorized Javascript Origins `https://internal.yourcompany.com` * Enter the correct Authorized Redirect URL `https://internal.yourcompany.com/oauth2/callback` * NOTE: `google_auth_proxy` will _only_ callback on the path `/oauth2/callback` 4. Under "APIs & Auth" choose "Consent Screen" * Fill in the necessary fields and Save (this is _required_) 5. Take note of the **Client ID** and **Client Secret** ## Configuration `google_auth_proxy` can be configured via [config file](#config-file), [command line options](#command-line-options) or [environment variables](#environment-variables). ### Config File An example [google_auth_proxy.cfg](contrib/google_auth_proxy.cfg.example) config file is in the contrib directory. It can be used by specifying `-config=/etc/google_auth_proxy.cfg` ### Command Line Options ``` Usage of google_auth_proxy: -authenticated-emails-file="": authenticate against emails via file (one per line) -client-id="": the Google OAuth Client ID: ie: "123456.apps.googleusercontent.com" -client-secret="": the OAuth Client Secret -config="": path to config file -cookie-domain="": an optional cookie domain to force cookies to (ie: .yourcompany.com) -cookie-expire=168h0m0s: expire timeframe for cookie -cookie-https-only=false: set HTTPS only cookie -cookie-secret="": the seed string for secure cookies -google-apps-domain=: authenticate against the given Google apps domain (may be given multiple times) -htpasswd-file="": additionally authenticate against a htpasswd file. Entries must be created with "htpasswd -s" for SHA encryption -http-address="127.0.0.1:4180": : to listen on for HTTP clients -pass-basic-auth=true: pass HTTP Basic Auth, X-Forwarded-User and X-Forwarded-Email information to upstream -redirect-url="": the OAuth Redirect URL. ie: "https://internalapp.yourcompany.com/oauth2/callback" -upstream=: the http url(s) of the upstream endpoint. If multiple, routing is based on path -version=false: print version string ``` ### Environment variables The environment variables `GOOGLE_AUTH_PROXY_CLIENT_ID`, `GOOGLE_AUTH_PROXY_CLIENT_SECRET`, `GOOGLE_AUTH_PROXY_COOKIE_SECRET`, `GOOGLE_AUTH_PROXY_COOKIE_DOMAIN` and `GOOGLE_AUTH_PROXY_COOKIE_EXPIRE` can be used in place of the corresponding command-line arguments. ### Example Nginx Configuration This example has a [Nginx](http://nginx.org/) SSL endpoint proxying to `google_auth_proxy` on port `4180`. `google_auth_proxy` then authenticates requests for an upstream application running on port `8080`. The external endpoint for this example would be `https://internal.yourcompany.com/`. An example Nginx config follows. Note the use of `Strict-Transport-Security` header to pin requests to SSL via [HSTS](http://en.wikipedia.org/wiki/HTTP_Strict_Transport_Security): ``` server { listen 443 default ssl; server_name internal.yourcompany.com; ssl_certificate /path/to/cert.pem; ssl_certificate_key /path/to/cert.key; add_header Strict-Transport-Security max-age=1209600; location / { proxy_pass http://127.0.0.1:4180; proxy_set_header Host $host; proxy_set_header X-Real-IP $remote_addr; proxy_set_header X-Scheme $scheme; proxy_connect_timeout 1; proxy_send_timeout 30; proxy_read_timeout 30; } } ``` The command line to run `google_auth_proxy` would look like this: ```bash ./google_auth_proxy \ --redirect-url="https://internal.yourcompany.com/oauth2/callback" \ --google-apps-domain="yourcompany.com" \ --upstream=http://127.0.0.1:8080/ \ --cookie-secret=... \ --cookie-https-only=true \ --client-id=... \ --client-secret=... ``` ## Endpoint Documentation Google Auth Proxy responds directly to the following endpoints. All other endpoints will be proxied upstream when authenticated. * /ping - returns an 200 OK response * /oauth2/sign_in - the login page, which also doubles as a sign out page (it clears cookies) * /oauth2/start - a URL that will redirect to start the OAuth cycle * /oauth2/callback - the URL used at the end of the OAuth cycle