oauth2-proxy/docs/2_auth.md

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default	Auth Configuration	/auth-configuration	2

OAuth Provider Configuration

You will need to register an OAuth application with a Provider (Google, GitHub or another provider), and configure it with Redirect URI(s) for the domain you intend to run oauth2-proxy on.

Valid providers are :

• Google default
• Azure
• Facebook
• GitHub
• Keycloak
• GitLab
• LinkedIn
• Microsoft Azure AD
• OpenID Connect
• login.gov
• Nextcloud
• DigitalOcean
• Bitbucket
• Gitea

The provider can be selected using the provider configuration value.

Please note that not all providers support all claims. The preferred_username claim is currently only supported by the OpenID Connect provider.

Google Auth Provider

For Google, the registration steps are:

1. Create a new project: https://console.developers.google.com/project
2. Choose the new project from the top right project dropdown (only if another project is selected)
3. In the project Dashboard center pane, choose "API Manager"
4. In the left Nav pane, choose "Credentials"
5. In the center pane, choose "OAuth consent screen" tab. Fill in "Product name shown to users" and hit save.
6. In the center pane, choose "Credentials" tab.
   • Open the "New credentials" drop down
   • Choose "OAuth client ID"
   • Choose "Web application"
   • Application name is freeform, choose something appropriate
   • Authorized JavaScript origins is your domain ex: https://internal.yourcompany.com
   • Authorized redirect URIs is the location of oauth2/callback ex: https://internal.yourcompany.com/oauth2/callback
   • Choose "Create"
7. Take note of the Client ID and Client Secret

It's recommended to refresh sessions on a short interval (1h) with cookie-refresh setting which validates that the account is still authorized.

Restrict auth to specific Google groups on your domain. (optional)

1. Create a service account: https://developers.google.com/identity/protocols/OAuth2ServiceAccount and make sure to download the json file.
2. Make note of the Client ID for a future step.
3. Under "APIs & Auth", choose APIs.
4. Click on Admin SDK and then Enable API.
5. Follow the steps on https://developers.google.com/admin-sdk/directory/v1/guides/delegation#delegate_domain-wide_authority_to_your_service_account and give the client id from step 2 the following oauth scopes:

https://www.googleapis.com/auth/admin.directory.group.readonly
https://www.googleapis.com/auth/admin.directory.user.readonly

6. Follow the steps on https://support.google.com/a/answer/60757 to enable Admin API access.
7. Create or choose an existing administrative email address on the Gmail domain to assign to the google-admin-email flag. This email will be impersonated by this client to make calls to the Admin SDK. See the note on the link from step 5 for the reason why.
8. Create or choose an existing email group and set that email to the google-group flag. You can pass multiple instances of this flag with different groups and the user will be checked against all the provided groups.
9. Lock down the permissions on the json file downloaded from step 1 so only oauth2-proxy is able to read the file and set the path to the file in the google-service-account-json flag.
10. Restart oauth2-proxy.

Note: The user is checked against the group members list on initial authentication and every time the token is refreshed ( about once an hour ).

Azure Auth Provider

1. Add an application: go to https://portal.azure.com, choose "Azure Active Directory" in the left menu, select "App registrations" and then click on "New app registration".
2. Pick a name and choose "Webapp / API" as application type. Use https://internal.yourcompany.com as Sign-on URL. Click "Create".
3. On the "Settings" / "Properties" page of the app, pick a logo and select "Multi-tenanted" if you want to allow users from multiple organizations to access your app. Note down the application ID. Click "Save".
4. On the "Settings" / "Required Permissions" page of the app, click on "Windows Azure Active Directory" and then on "Access the directory as the signed in user". Hit "Save" and then then on "Grant permissions" (you might need another admin to do this).
5. On the "Settings" / "Reply URLs" page of the app, add https://internal.yourcompanycom/oauth2/callback for each host that you want to protect by the oauth2 proxy. Click "Save".
6. On the "Settings" / "Keys" page of the app, add a new key and note down the value after hitting "Save".
7. Configure the proxy with

   --provider=azure
   --client-id=<application ID from step 3>
   --client-secret=<value from step 6>

Note: When using the Azure Auth provider with nginx and the cookie session store you may find the cookie is too large and doesn't get passed through correctly. Increasing the proxy_buffer_size in nginx or implementing the redis session storage should resolve this.

Facebook Auth Provider

1. Create a new FB App from https://developers.facebook.com/
2. Under FB Login, set your Valid OAuth redirect URIs to https://internal.yourcompany.com/oauth2/callback

GitHub Auth Provider

1. Create a new project: https://github.com/settings/developers
2. Under Authorization callback URL enter the correct url ie https://internal.yourcompany.com/oauth2/callback

The GitHub auth provider supports two additional ways to restrict authentication to either organization and optional team level access, or to collaborators of a repository. Restricting by these options is normally accompanied with --email-domain=*

NOTE: When --github-user is set, the specified users are allowed to login even if they do not belong to the specified org and team or collaborators.

To restrict by organization only, include the following flag:

-github-org="": restrict logins to members of this organisation

To restrict within an organization to specific teams, include the following flag in addition to -github-org:

-github-team="": restrict logins to members of any of these teams (slug), separated by a comma

If you would rather restrict access to collaborators of a repository, those users must either have push access to a public repository or any access to a private repository:

-github-repo="": restrict logins to collaborators of this repository formatted as orgname/repo

If you'd like to allow access to users with read only access to a public repository you will need to provide a token for a user that has write access to the repository. The token must be created with at least the public_repo scope:

-github-token="": the token to use when verifying repository collaborators

To allow a user to login with their username even if they do not belong to the specified org and team or collaborators, separated by a comma

-github-user="": allow logins by username, separated by a comma

If you are using GitHub enterprise, make sure you set the following to the appropriate url:

-login-url="http(s)://<enterprise github host>/login/oauth/authorize"
-redeem-url="http(s)://<enterprise github host>/login/oauth/access_token"
-validate-url="http(s)://<enterprise github host>/api/v3"

Keycloak Auth Provider

1. Create new client in your Keycloak with Access Type 'confidental' and Valid Redirect URIs 'https://internal.yourcompany.com/oauth2/callback'
2. Take note of the Secret in the credential tab of the client
3. Create a mapper with Mapper Type 'Group Membership' and Token Claim Name 'groups'.

Make sure you set the following to the appropriate url:

-provider=keycloak
-client-id=<client you have created>
-client-secret=<your client's secret>
-login-url="http(s)://<keycloak host>/realms/<your realm>/protocol/openid-connect/auth"
-redeem-url="http(s)://<keycloak host>/realms/<your realm>/protocol/openid-connect/token"
-validate-url="http(s)://<keycloak host>/realms/<your realm>/protocol/openid-connect/userinfo"
-keycloak-group=<user_group>

The group management in keycloak is using a tree. If you create a group named admin in keycloak you should define the 'keycloak-group' value to /admin.

GitLab Auth Provider

Whether you are using GitLab.com or self-hosting GitLab, follow these steps to add an application. Make sure to enable at least the openid, profile and email scopes.

Restricting by group membership is possible with the following option:

-gitlab-group="": restrict logins to members of any of these groups (slug), separated by a comma

If you are using self-hosted GitLab, make sure you set the following to the appropriate URL:

-oidc-issuer-url="<your gitlab url>"

LinkedIn Auth Provider

For LinkedIn, the registration steps are:

1. Create a new project: https://www.linkedin.com/secure/developer
2. In the OAuth User Agreement section:
   • In default scope, select r_basicprofile and r_emailaddress.
   • In "OAuth 2.0 Redirect URLs", enter https://internal.yourcompany.com/oauth2/callback
3. Fill in the remaining required fields and Save.
4. Take note of the Consumer Key / API Key and Consumer Secret / Secret Key

Microsoft Azure AD Provider

For adding an application to the Microsoft Azure AD follow these steps to add an application.

Take note of your TenantId if applicable for your situation. The TenantId can be used to override the default common authorization server with a tenant specific server.

OpenID Connect Provider

OpenID Connect is a spec for OAUTH 2.0 + identity that is implemented by many major providers and several open source projects. This provider was originally built against CoreOS Dex and we will use it as an example.

1. Launch a Dex instance using the getting started guide.

2. Setup oauth2-proxy with the correct provider and using the default ports and callbacks.

3. Login with the fixture use in the dex guide and run the oauth2-proxy with the following args:

   -provider oidc -provider-display-name "My OIDC Provider" -client-id oauth2-proxy -client-secret proxy -redirect-url http://127.0.0.1:4180/oauth2/callback -oidc-issuer-url http://127.0.0.1:5556 -cookie-secure=false -email-domain example.com

The OpenID Connect Provider (OIDC) can also be used to connect to other Identity Providers such as Okta. To configure the OIDC provider for Okta, perform the following steps:

Configuring the OIDC Provider with Okta

1. Log in to Okta using an administrative account. It is suggested you try this in preview first, example.oktapreview.com
2. (OPTIONAL) If you want to configure authorization scopes and claims to be passed on to multiple applications, you may wish to configure an authorization server for each application. Otherwise, the provided default will work.

• Navigate to Security then select API
• Click Add Authorization Server, if this option is not available you may require an additional license for a custom authorization server.
• Fill out the Name with something to describe the application you are protecting. e.g. 'Example App'.
• For Audience, pick the URL of the application you wish to protect: https://example.corp.com
• Fill out a Description
• Add any Access Policies you wish to configure to limit application access.
• The default settings will work for other options. See Okta documentation for more information on Authorization Servers

3. Navigate to Applications then select Add Application.

• Select Web for the Platform setting.
• Select OpenID Connect and click Create
• Pick an Application Name such as Example App.
• Set the Login redirect URI to https://example.corp.com.
• Under General set the Allowed grant types to Authorization Code and Refresh Token.
• Leave the rest as default, taking note of the Client ID and Client Secret.
• Under Assignments select the users or groups you wish to access your application.

4. Create a configuration file like the following:

provider = "oidc"
redirect_url = "https://example.corp.com/oauth2/callback"
oidc_issuer_url = "https://corp.okta.com/oauth2/abCd1234"
upstreams = [
    "https://example.corp.com"
]
email_domains = [
    "corp.com"
]
client_id = "XXXXX"
client_secret = "YYYYY"
pass_access_token = true
cookie_secret = "ZZZZZ"
skip_provider_button = true

The oidc_issuer_url is based on URL from your Authorization Server's Issuer field in step 2, or simply https://corp.okta.com The client_id and client_secret are configured in the application settings. Generate a unique client_secret to encrypt the cookie.

Then you can start the oauth2-proxy with ./oauth2-proxy -config /etc/example.cfg

Configuring the OIDC Provider with Okta - localhost

1. Signup for developer account: https://developer.okta.com/signup/
2. Create New Web Application: https://${your-okta-domain}/dev/console/apps/new
3. Example Application Settings for localhost:
   • Name: My Web App
   • Base URIs: http://localhost:4180/
   • Login redirect URIs: http://localhost:4180/oauth2/callback
   • Logout redirect URIs: http://localhost:4180/
   • Group assignments: Everyone
   • Grant type allowed: Authorization Code and Refresh Token
4. Make note of the Client ID and Client secret, they are needed in a future step
5. Make note of the default Authorization Server Issuer URI from: https://${your-okta-domain}/admin/oauth2/as
6. Example config file /etc/localhost.cfg

   provider = "oidc"
   redirect_url = "http://localhost:4180/oauth2/callback"
   oidc_issuer_url = "https://${your-okta-domain}/oauth2/default"
   upstreams = [
       "http://0.0.0.0:8080"
   ]
   email_domains = [
       "*"
   ]
   client_id = "XXX"
   client_secret = "YYY"
   pass_access_token = true
   cookie_secret = "ZZZ"
   cookie_secure = false
   skip_provider_button = true
   # Note: use the following for testing within a container
   # http_address = "0.0.0.0:4180"
   

7. Then you can start the oauth2-proxy with ./oauth2-proxy -config /etc/localhost.cfg

login.gov Provider

login.gov is an OIDC provider for the US Government. If you are a US Government agency, you can contact the login.gov team through the contact information that you can find on https://login.gov/developers/ and work with them to understand how to get login.gov accounts for integration/test and production access.

A developer guide is available here: https://developers.login.gov/, though this proxy handles everything but the data you need to create to register your application in the login.gov dashboard.

As a demo, we will assume that you are running your application that you want to secure locally on http://localhost:3000/, that you will be starting your proxy up on http://localhost:4180/, and that you have an agency integration account for testing.

First, register your application in the dashboard. The important bits are:

• Identity protocol: make this Openid connect
• Issuer: do what they say for OpenID Connect. We will refer to this string as ${LOGINGOV_ISSUER}.
• Public key: This is a self-signed certificate in .pem format generated from a 2048 bit RSA private key. A quick way to do this is openssl req -x509 -newkey rsa:2048 -keyout key.pem -out cert.pem -days 3650 -nodes -subj '/C=US/ST=Washington/L=DC/O=GSA/OU=18F/CN=localhost', The contents of the key.pem shall be referred to as ${OAUTH2_PROXY_JWT_KEY}.
• Return to App URL: Make this be http://localhost:4180/
• Redirect URIs: Make this be http://localhost:4180/oauth2/callback.
• Attribute Bundle: Make sure that email is selected.

Now start the proxy up with the following options:

./oauth2-proxy -provider login.gov \
  -client-id=${LOGINGOV_ISSUER} \
  -redirect-url=http://localhost:4180/oauth2/callback \
  -oidc-issuer-url=https://idp.int.identitysandbox.gov/ \
  -cookie-secure=false \
  -email-domain=gsa.gov \
  -upstream=http://localhost:3000/ \
  -cookie-secret=somerandomstring12341234567890AB \
  -cookie-domain=localhost \
  -skip-provider-button=true \
  -pubjwk-url=https://idp.int.identitysandbox.gov/api/openid_connect/certs \
  -profile-url=https://idp.int.identitysandbox.gov/api/openid_connect/userinfo \
  -jwt-key="${OAUTH2_PROXY_JWT_KEY}"

You can also set all these options with environment variables, for use in cloud/docker environments. One tricky thing that you may encounter is that some cloud environments will pass in environment variables in a docker env-file, which does not allow multiline variables like a PEM file. If you encounter this, then you can create a jwt_signing_key.pem file in the top level directory of the repo which contains the key in PEM format and then do your docker build. The docker build process will copy that file into your image which you can then access by setting the OAUTH2_PROXY_JWT_KEY_FILE=/etc/ssl/private/jwt_signing_key.pem environment variable, or by setting --jwt-key-file=/etc/ssl/private/jwt_signing_key.pem on the commandline.

Once it is running, you should be able to go to http://localhost:4180/ in your browser, get authenticated by the login.gov integration server, and then get proxied on to your application running on http://localhost:3000/. In a real deployment, you would secure your application with a firewall or something so that it was only accessible from the proxy, and you would use real hostnames everywhere.

Skip OIDC discovery

Some providers do not support OIDC discovery via their issuer URL, so oauth2-proxy cannot simply grab the authorization, token and jwks URI endpoints from the provider's metadata.

In this case, you can set the --skip-oidc-discovery option, and supply those required endpoints manually:

    -provider oidc
    -client-id oauth2-proxy
    -client-secret proxy
    -redirect-url http://127.0.0.1:4180/oauth2/callback
    -oidc-issuer-url http://127.0.0.1:5556
    -skip-oidc-discovery
    -login-url http://127.0.0.1:5556/authorize
    -redeem-url http://127.0.0.1:5556/token
    -oidc-jwks-url http://127.0.0.1:5556/keys
    -cookie-secure=false
    -email-domain example.com

Nextcloud Provider

The Nextcloud provider allows you to authenticate against users in your Nextcloud instance.

When you are using the Nextcloud provider, you must specify the urls via configuration, environment variable, or command line argument. Depending on whether your Nextcloud instance is using pretty urls your urls may be of the form /index.php/apps/oauth2/* or /apps/oauth2/*.

Refer to the OAuth2 documentation to setup the client id and client secret. Your "Redirection URI" will be https://internalapp.yourcompany.com/oauth2/callback.

    -provider nextcloud
    -client-id <from nextcloud admin>
    -client-secret <from nextcloud admin>
    -login-url="<your nextcloud url>/index.php/apps/oauth2/authorize"
    -redeem-url="<your nextcloud url>/index.php/apps/oauth2/api/v1/token"
    -validate-url="<your nextcloud url>/ocs/v2.php/cloud/user?format=json"

Note: in all cases the validate-url will not have the index.php.

DigitalOcean Auth Provider

1. Create a new OAuth application
   • You can fill in the name, homepage, and description however you wish.
   • In the "Application callback URL" field, enter: https://oauth-proxy/oauth2/callback, substituting oauth2-proxy with the actual hostname that oauth2-proxy is running on. The URL must match oauth2-proxy's configured redirect URL.
2. Note the Client ID and Client Secret.

To use the provider, pass the following options:

   --provider=digitalocean
   --client-id=<Client ID>
   --client-secret=<Client Secret>

Alternatively, set the equivalent options in the config file. The redirect URL defaults to https://<requested host header>/oauth2/callback. If you need to change it, you can use the --redirect-url command-line option.

Bitbucket Auth Provider

1. Add a new OAuth consumer
   • In "Callback URL" use https://<oauth2-proxy>/oauth2/callback, substituting <oauth2-proxy> with the actual hostname that oauth2-proxy is running on.
   • In Permissions section select:
     • Account -> Email
     • Team membership -> Read
     • Repositories -> Read
2. Note the Client ID and Client Secret.

To use the provider, pass the following options:

   --provider=bitbucket
   --client-id=<Client ID>
   --client-secret=<Client Secret>

The default configuration allows everyone with Bitbucket account to authenticate. To restrict the access to the team members use additional configuration option: --bitbucket-team=<Team name>. To restrict the access to only these users who has access to one selected repository use --bitbucket-repository=<Repository name>.

Gitea Auth Provider

1. Create a new application: https://< your gitea host >/user/settings/applications
2. Under Redirect URI enter the correct URL i.e. https://<proxied host>/oauth2/callback
3. Note the Client ID and Client Secret.
4. Pass the following options to the proxy:

    --provider="github"
    --redirect-url="https://<proxied host>/oauth2/callback"
    --provider-display-name="Gitea"
    --client-id="< client_id as generated by Gitea >"
    --client-secret="< client_secret as generated by Gitea >"
    --login-url="https://< your gitea host >/login/oauth/authorize"
    --redeem-url="https://< your gitea host >/login/oauth/access_token"
    --validate-url="https://< your gitea host >/api/v1"

Email Authentication

To authorize by email domain use --email-domain=yourcompany.com. To authorize individual email addresses use --authenticated-emails-file=/path/to/file with one email per line. To authorize all email addresses use --email-domain=*.

Adding a new Provider

Follow the examples in the [providers package]({{ site.gitweb }}/providers/) to define a new Provider instance. Add a new case to [providers.New()]({{ site.gitweb }}/providers/providers.go) to allow oauth2-proxy to use the new Provider.