OmniAuth::OpenIDConnect renewed

Authentication strategy using OpenID Connect for OmniAuth2.

The original is jjbohn/omniauth-openid-connect. I gathered the changes that were scattered in many places and integrated them here. In particular, Shopify/omniauth-identity, patatoid/omniauth-openid-reconnect and m0n9oose/omniauth_openid_connect.

This package is the successor to the following:

omniauth-google-oauth2
omniauth-yahoojp
omniauth-azure-oauth2
omniauth-azure-adv2
omniauth-line
omniauth-line-openid-connect
omniauth-salesforce

Important: OmniAuth v1.9.1 and earlier is vulnerable to Cross-Site Request Forgery. Application developers need to avoid this vulnerability. See CVE-2015-9284, Resolving CVE 2015 9284 · omniauth/omniauth Wiki.

OpenID Connect

If you use the raw OAuth 2.0 for authentication purposes, it will cause a huge security vulnerability. The OAuth 2.0 is a mechanism for authorization and does not identify who the access token belongs to. Therefore, there is a risk of token hijacking.

Each company has created its countermeasures. OpenID Connect is a standardized, simple identity layer on top of the OAuth 2.0 protocol. By using OpenID Connect, we don't need to implement variety extensions of each company.

OpenID Connect uses a mechanism id_token. In addition to access_token, the authentication server and clients exchange the id_token, and verifying the signature and nonce makes preventing spoofing.

There is no technical continuity with OpenID 2.0 and OpenID Connect. Only names are similar. For more information on OpenID Connect, see OpenID Connect Core 1.0.

Features

OmniAuth::OpenIDConnect renewed is tested under Ruby v2.5, v2.6, v2.7 and v3.0.

Single Sign-On: OpenID Connect Core 1.0 the Authorization Code Flow and the Implicit Flow. Single Logout (SLO): OpenID Connect RP-Initiated Logout 1.0.

Tested OpenID Providers

Organization	Implementation	Note
Google	Google Identity Platform	Developer's Guide
Yahoo! JAPAN	Yahoo! ID連携 v2	Developer's Guide
Microsoft	Azure Active Directory (v1), Microsoft ID Platform (v2)	Understand the OpenID Connect authentication code flow in Azure AD
nov	OpenID Connect OP sample	Sample Application
Red Hat	Keycloak	Securing Applications

~~(2017-09) As of now, Azure AD doesn't meet the OpenID Connect specification. You must set true of :send_client_secret_to_token_endpoint option.~~ (2020.6) OmniAuth::OpenIDConnect v0.8 has configured automatically for Azure AD. Simply set the option discovery:true.

Installation

This repository is a forked version. You can install gem file locally. Clone this repository:

$ git clone https://github.com/netsphere-labs/omniauth-openid-connect.git
$ cd omniauth-openid-connect
$ git checkout v0.8.1.pre
$ rake build
omniauth-openid-connect 0.8.1.pre built to pkg/omniauth-openid-connect-0.8.1.pre.gem.
$ su
# rake install:local
omniauth-openid-connect (0.8.1.pre) installed.
# gem list omniauth-openid-connect
omniauth-openid-connect (0.8.1.pre)

Gemfile:

    # 認証系
    gem "omniauth"

    # Facebook OAuth2 Strategy for OmniAuth
    # https://github.com/mkdynamic/omniauth-facebook
    gem "omniauth-facebook"

    # OpenID Connect対応
    # googleはこちら。
    gem 'openid_connect', '1.1.5'   # バージョン固定.
    gem "omniauth-openid-connect"

And then execute:

$ bundle

Usage

A sample Rails program: https://gitlab.com/netsphere/rails-examples/-/tree/main/omniauth-oidc-rp-sample/

Manual: https://www.nslabs.jp/omniauth-openid-connect.rhtml

Options Overview

Field	Description	Required	Default
name [Symbol or String]	Arbitrary string to identify connection and identify it from other openid_connect providers `:my_idp`	Yes	`'openid_connect'`
`issuer` [String]	IdP identifier URI `https://auth.login.yahoo.co.jp/yconnect/v2`	Yes	--
`discovery`	Should OpenID discovery be used. This is recommended if the IdP provides a discovery endpoint. See client config for how to manually enter discovered values. one of: true, false	no	false
`client_auth_method`	Which authentication method to use to authenticate your app with the authorization server's token endpoint `:basic`, `:secret_in_body`	no	Sym: basic
scope	Which OpenID scopes to include (`:openid` is always required) [:openid, :profile, :email]	no	Array [:openid]
response_type	Which OAuth2 response type to use with the authorization request. one of: 'code', ['id_token', 'token'] Security issue: Do not use 'token' or 'id_token'. The 'id_token' is used for only Self-Issued OpenID Providers. Instead, use ['id_token', 'token'] (the Implicit Flow).	no	String: code
state	A value to be used for the OAuth2 state parameter on the authorization request. Can be a proc that generates a string. `Proc.new {SecureRandom.hex(32)}`	no	Random 16 character string
`response_mode`	The response mode per OAuth 2.0 Form Post Response Mode one of: :query, :fragment, :form_post, :web_message	No. [NOT RECOMMENDED]	nil
display	An optional parameter to the authorization request to determine how the authorization and consent page one of: :page, :popup, :touch, :wap	no	nil
prompt	An optional parameter to the authrization request to determine what pages the user will be shown one of: :none, :login, :consent, :select_account	no	nil
send_scope_to_token_endpoint	Should the scope parameter be sent to the authorization token endpoint? one of: true, false	no	true
`post_logout_redirect_uri`	The redirect-back URI after IdP's logout. To use per the OpenID Connect RP-Initiated Logout 1.0 `https://myapp.com/logout/callback`	no	empty
uid_field	The field of the user info response to be used as a unique id "sub", "preferred_username"	no	'sub'
client_options	A hash of client options detailed in its own section	yes

Additional Configuration Notes

name is arbitrary, I recommend using the name of your provider. The name configuration exists because you could be using multiple OpenID Connect providers in a single app.

NOTE: if you use this gem with Devise you should use :openid_connect name, or Devise would route to 'users/auth/:provider' rather than 'users/auth/openid_connect'

response_type tells the authorization server which grant type the application wants to use, currently, only 'code' (Authorization Code grant) and ['id_token', 'token'] (Implicit grant) are valid. Do not use id_token. This is valid only under Self-Issued OpenID Providers.
If you want to pass state paramete by yourself. You can set Proc Object. e.g. state: Proc.new { SecureRandom.hex(32) }
ON Authorization Code Flow, nonce is optional. If you don't want to pass the "nonce" parameter to provider, you should specify false to send_nonce option (default true). On Implicit Flow, the nonce is required. send_nonce option is ignored.

Client Config Options

These are the configuration options for the client_options hash of the configuration.

Field	Description	Default	Replaced by discovery?
identifier	The OAuth2 client_id
secret	The OAuth2 client secret
redirect_uri	The OAuth2 authorization callback url in your app
scheme	The http scheme to use. If not set, built by `options.issuer`	https
host	The host of the authorization server. If not set, built by `options.issuer`	nil
port	The port for the authorization server. If not set, built by `options.issuer`	nil
authorization_endpoint	The authorize endpoint on the authorization server	/authorize	yes
token_endpoint	The token endpoint on the authorization server	/token	yes
userinfo_endpoint	The user info endpoint on the authorization server	/userinfo	yes
expires_in		nil

These are strategy's options.

Field	Description	Default	Replaced by discovery?
jwks_uri	The `jwks_uri` on the authorization server	/jwk	yes
end_session_endpoint	The url to call to log the user out at the authorization server. See OpenID Connect RP-Initiated Logout 1.0	nil	yes

Metadata Discovery

See OpenID Connect Discovery 1.0

If the provider supports "OpenID Connect Discovery", You should specify true to discovery option. (default false)
In the "OpenID Connect Discovery", generally provider has Webfinger endpoint. If provider does not have Webfinger endpoint, You can specify "Issuer" to option. e.g. issuer: "https://myprovider.com" It means to get configuration from "https://myprovider.com/.well-known/openid-configuration".
The uid is by default using the sub value from the user_info response, which in some applications is not the expected value. To avoid such limitations, the uid label can be configured by providing the omniauth uid_field option to a different label (i.e. preferred_username) that appears in the user_info details.
The issuer property should exactly match the provider's issuer link.
Some OpenID Connect providers require the scope attribute in requests to the token endpoint, even if this is not in the protocol specifications. In those cases, the send_scope_to_token_endpoint property can be used to add the attribute to the token request. Initial value is true, which means that the scope attribute is included by default.

Contributing

Fork it ( https://github.com/netsphere-labs/omniauth-openid-connect )
Create your feature branch (git checkout -b my-new-feature)
Cover your changes with tests and make sure they're green (bundle install && bundle exec rake test)
Commit your changes (git commit -am 'Add some feature')
Push to the branch (git push origin my-new-feature)
Create new Pull Request

ondrejpialek/omniauth-openid-connect