# Proof of concept OpenID Connect / OAuth server with ORY Hydra

This repository contains a proof of concept implementation for an identity
provider and an application using OIDC. [ORY Hydra](https://www.ory.sh/hydra/)
is used for the actual OAuth2 / OpenID Connect operations. The implementation
in this repository provides the UI components that are required by Hydra.

## Setup

### Certificates

You need a set of certificates for the IDP, the application and Hydra. You
can use the Test CA created by the ``setup_test_ca.sh`` script from the
[CAcert developer setup](https://git.dittberner.info/jan/cacert-devsetup)
repository like this:

1. create signing requests

   ```
   mkdir certs
   cd certs
   openssl req -new -newkey rsa:3072 -nodes \
       -keyout hydra.cacert.localhost.key \
       -out hydra.cacert.localhost.csr.pem \
       -subj /CN=hydra.cacert.localhost \
       -addext subjectAltName=DNS:hydra.cacert.localhost,DNS:auth.cacert.localhost
   openssl req -new -newkey rsa:3072 -nodes \
       -keyout idp.cacert.localhost.key \
       -out idp.cacert.localhost.csr.pem \
       -subj /CN=idp.cacert.localhost \
       -addext subjectAltName=DNS:idp.cacert.localhost,DNS:login.cacert.localhost,DNS:register.cacert.localhost
   openssl req -new -newkey rsa:3072 -nodes \
       -keyout app.cacert.localhost.key \
       -out app.cacert.localhost.csr.pem \
       -subj /CN=app.cacert.localhost \
       -addext subjectAltName=DNS:app.cacert.localhost
   cp *.csr.pem $PATH_TO_DEVSETUP_TESTCA/
   ```

2. Use the CA to sign the certificates

   ```
   pushd $PATH_TO_DEVSETUP_TESTCA/
   for csr in hydra idp app; do
       openssl ca -config ca.cnf -name class3_ca -extensions server_ext \
           -in ${csr}.cacert.localhost.csr.pem \
           -out ${csr}.cacert.localhost.crt.pem -days 365
   done
   popd
   cp $PATH_TO_DEVSETUP_TESTCA/{hydra,idp,app}.cacert.localhost.crt.pem .
   ```

3. Copy CA certificate for client certificates
  
   ```
   openssl x509 -in $PATH_TO_DEVSETUP_TESTCA/class3/ca.crt.pem \
       -out client_ca.pem
   ```

### Setup Hydra

We use the ORY Hydra OAuth2 / OpenID Connect implementation. Install Hydra
according to their [documentation](https://www.ory.sh/hydra/docs/install).
The setup has been tested with the Linux binary installation.

Perform the Hydra database setup:

```
sudo -i -u postgres psql
> CREATE DATABASE hydra_local ENCODING utf-8;
> CREATE USER hydra_local WITH PASSWORD '${YOUR_POSTGRESQL_PASSWORD}';
> GRANT CONNECT, CREATE ON DATABASE hydra_local TO hydra_local;

hydra migrate sql "postgres://hydra_local:${YOUR_POSTGRESQL_PASSWORD}@localhost:5432/hydra_local"
```

Create a configuration file for Hydra i.e. ``hydra.yaml``:

```
serve:
  admin:
    host: hydra.cacert.localhost
  public:
    host: auth.cacert.localhost
  tls:
    cert:
      path: certs/hydra.cacert.localhost.crt.pem
    key:
      path: certs/hydra.cacert.localhost.key
  dsn: 'postgres://hydra_local:${YOUR_POSTGRESQL_PASSWORD}@localhost:5432/hydra_local'

webfinger:
  oidc_discovery:
    supported_claims:
      - email
      - email_verified
      - given_name
      - family_name
      - middle_name
      - name
      - birthdate
      - zoneinfo
      - locale
      - https://cacert.localhost/groups
    supported_scope:
      - profile
      - email

oauth2:
  expose_internal_errors: false

urls:
  login: https://login.cacert.localhost:3000/login
  consent: https://login.cacert.localhost:3000/consent
  logout: https://login.cacert.localhost:3000/logout
  error: https://login.cacert.localhost:3000/error
  post_logout_redirect: https://login.cacert.localhost:3000/logout-successful
  self:
    public: https://auth.cacert.localhost:4444/
    issuer: https://auth.cacert.localhost:4444/

secrets:
  system:
    - "${YOUR SECRET FOR HYDRA}"
```

The available configuration options are described in the
[Hydra configuration documentation](https://www.ory.sh/hydra/docs/reference/configuration).

Hydra needs to be able to resolve its hostnames and does not work with the
systemd-nss module. You therefore need to define Hydra's hostnames in your
``/etc/hosts`` file:

```
::1 auth.cacert.localhost hydra.cacert.localhost
```

### Add OpenID Connect configuration for a client

Create an OpenID Connect (OIDC) client configuration for the demo application

```
hydra clients create --endpoint https://hydra.cacert.localhost:4445/ \
    --callbacks https://app.cacert.localhost:4000/callback \
    --logo-uri https://register.cacert.localhost:3000/images/app.png \
    --name "Client App Demo" \
    --scope "openid offline_access profile email" \
    --post-logout-callbacks https://app.cacert.localhost:4000/after-logout \
    --client-uri https://register.cacert.localhost:3000/info/app
```

The command returns a client id and a client secret, that you need for the
demo application configuration.

### Configure IDP

The Identity Provider application (IDP) requires a strong random key for its
CSRF cookie. You can generate such a key using the following openssl command:

```
openssl rand -base64 32
```

Use this value and the database credentials from your cacert-devsetup and
create `idp.toml`:

```
[security]
csrf.key = "<32 bytes of base64 encoded data>"
  
[db]
dsn = "$MYSQL_USER:$MYSQL_PASSWORD@tcp(localhost:13306)/cacert
```

### Configure the Demo Application

You will need a 32 byte and a 64 byte random secret for the session
authentication and encryption keys:

```
openssl rand -base64 64
openssl rand -base64 32
```

You also need the client id and the client secret, that have been generated
during the OIDC client setup described above.

```
[oidc]
client-id = "<client id from hydra clients invocation>"
client-secret = "<client secret from hydra clients invocation>"

[session]
auth-key = "<64 bytes of base64 encoded data>"
enc-key = "<32 bytes of base64 encoded data>"
```

## Frontend resource build

The frontend resources are built using [webpack 5](https://webpack.js.org/)
and [yarn](https://classic.yarnpkg.com/lang/en/). You need recent nodejs
and yarn versions. See the
[Debian installation instructions](https://github.com/nodesource/distributions/blob/master/README.md#debinstall)
of nodesource or look at the other options on the
[nodejs Download page](https://nodejs.org/en/download/) if you cannot use
Debian Bullseye or newer.

When you are sure that you have nodejs >= 12 and yarn you can install the
required dependencies and run webpack like this:

```
yarn
yarn run build
```

## Start

Now you can start Hydra, the IDP and the demo app in 3 terminal windows:

  ```
  hydra serve all --config hydra.yaml
  ```

  ```
  go run cmd/idp/main.go
  ```

  ```
  go run cmd/app/main.go
  ```

Visit https://app.cacert.localhost:4000/ in a Browser and you will be directed
through the OpenID connect authorization code flow.

## Translations

This application uses [go-i18n](https://github.com/nicksnyder/go-i18n/) for internationalization (i18n) support.

The translation workflow needs the `go18n` binary which can be installed via

```
go get -u  github.com/nicksnyder/go-i18n/v2/goi18n
```

To extract new messages from the code run

```
goi18n extract .
```

Then use

```
goi18n merge active.*.toml
```

to create TOML files for translation as `translate.<locale>.toml`. After translating the messages run

```
goi18n merge active.*.toml translate.*.toml
```

to merge the messages back into the active translation files. To add a new language you need to add the language code
to the languages configuration option (default is defined in the configmap in cmd/idp/main.go and cmd/app/main.go).