Werther ¹

Werther is an Identity Provider for ORY Hydra over LDAP. It implements Login And Consent Flow and provides basic UI.

Features

• Support Active Directory;
• Mapping LDAP attributes to OpenID Connect claims;
• Mapping LDAP groups to user roles;
• OAuth 2.0 scopes;
• Caching users roles;
• UI customization.

Limitations

• Werther grants all requested permissions to a client without displaying the consent page;
• Werther confirms a logout request without displaying the logout confirmation page.

Requirements

ORY Hydra v1.0.0-rc.12 or higher.

Table of Contents

• Installing
• Configuration
• User roles
• UI customization
• Example
• Resources
• Footnotes
• Contributing
• License

Installing

From Docker

docker pull icoreru/werther

From sources

go install ./...

Configuration

The application is configured via environment variables. Names of the environment variables starts with prefix WERTHER_. See a list of the environment variables using the command:

werther -h

User roles

In LDAP user's roles are groups in which a user is a member.

The environment variable WERTHER_LDAP_ROLE_DN is a DN for searching roles.

For example, create an OU that repserents an application, and then in the created OU create groups that represent application's roles:

dc=com
|-- dc=example
    |-- ou=AppRoles
        |-- ou=App1
            |-- cn=app1_role1 (objectClass="group", description="role1")
            |-- cn=app1_role2 (objectClass="group", description="role2")

Run Werther with the environment variable WERTHER_LDAP_ROLE_DN that equals to ou=AppRoles,dc=example,dc=com.

In the above example Werther returns user's roles as a value of the user role's claim https://github.com/i-core/werther/claims/roles.

{
    "https://github.com/i-core/werther/claims/roles": {
        "App1": ["role1", "role2"],
    }
}

To customize the roles claim's name you should set a value of the environment variable WERTHER_LDAP_ROLE_CLAIM. Also you should map the custom name of the roles' claim to a roles's scope using the environment variable WERTHER_IDENTP_CLAIM_SCOPES (the name must be URL encoded):

env WERTHER_LDAP_ROLE_CLAIM=https://my-company.com/claims/roles                                                                                     \
    WERTHER_IDENTP_CLAIM_SCOPES=name:profile,family_name:profile,given_name:profile,email:email,https%3A%2F%2Fmy-company.com%2Fclaims%2Froles:roles \
    werther

For more details about claims naming see OpenID Connect Core 1.0.

NB There are cases when we need to create several roles with the same name in LDAP. For example, when we want to configure multiple applications or several environments for the same application.

dc=com
|-- dc=example
    |-- ou=AppRoles
        |-- ou=Test
            |-- ou=App1
                |-- cn=test_app1_role1 (objectClass="group", description="role1")
                |-- cn=test_app1_role2 (objectClass="group", description="role2")
            |-- ou=App2
                |-- cn=test_app2_role1 (objectClass="group",description-"role1")
                |-- cn=test_app2_role2 (objectClass="group",description-"role2")
        |-- ou=Dev
            |-- ou=App1
                |-- cn=dev_app1_role1 (objectClass="group", description="role1")
                |-- cn=dev_app1_role3 (objectClass="group", description="role3")
            |-- ou=App2
                |-- cn=dev_app2_role1 (objectClass="group",description-"role1")
                |-- cn=dev_app2_role4 (objectClass="group",description-"role4")

Active Directory requires unique CNs in a domain. But in Active Directory creating groups with the same CN in different OUs is difficult. Because of it, Werther uses a LDAP attribute as a role's name instead of CN. A name of a LDAP attribute is specified using the environment variable WERTHER_LDAP_ROLE_ATTR, and has the default value description.

In the above example, Werther returns a response that contains the next roles:

• when the environment variable WERTHER_LDAP_ROLE_DN equals to ou=Test,ou=AppRoles,dc=example,dc=com:

  {
      "https://github.com/i-core/werther/claims/roles": {
          "App1": ["role1", "role2"],
          "App2": ["role1", "role2"]
      }
  }
  

• when the environment variable WERTHER_LDAP_ROLE_DN equals to ou=Dev,ou=AppRoles,dc=example,dc=com:

  {
      "https://github.com/i-core/werther/claims/roles": {
          "App1": ["role1", "role3"],
          "App2": ["role1", "role4"]
      }
  }
  

UI customization

Werther uses the Go templates to render UI pages. To customize the UI you should create a directory that contains UI pages' templates. After that you should set the directory path to the environment variable WERTHER_WEB_DIR.

Custom login page

A login page's template must be a Go template. The template has access to data conforming the next JSON-schema:

type: object
properties:
  - WebBasePath:
      description: The base path of the login page
      type: string
  - LangPrefs:
      description: The user language preferences (the parsed value of the header Accept-Language)
      type: array
      items:
        type: object
        properties:
          - Lang:
              description: The language canonical name.
              type: string
          - Weight:
              description: The language weight.
              type: number
        required:
          - Lang
          - Weight
  - Data:
      type: object
      properties:
        - CSRFToken:
            description: A CSRF token.
            type: string
        - Challenge:
            description: A login challenge ID.
            type: string
        - LoginURL:
            description: An endpoint that finishes the login process.
            type: string
        - IsInvalidCredentials:
            description: Specifies that a user types an invalid username or password.
            type: boolean
        - IsInternalError:
            description: Specifies that an internal server error happens when finishing the login process.
            type: boolean
      required:
        - CSRFToken
        - Challenge
        - LoginURL
        - IsInvalidCredentials
        - IsInternalError
required:
  - WebBasePath
  - LangPrefs
  - Data

When a login page's template contains static resources (like styles, scripts, and images) they must be placed in a subdirectory called static.

For a full example of a login page's template see source code.

Custom login page (old format)

The old template format is also supported but it will be removed in the future major release.

A login page's template should contains blocks title, style, script, content. Each block has access to data conforming the next JSON-schema:

type: object
properties:
  - CSRFToken:
    description: A CSRF token.
    type: string
  - Challenge:
    description: A login challenge ID.
    type: string
  - LoginURL:
    description: An endpoint that finishes the login process.
    type: string
  - IsInvalidCredentials:
    description: Specifies that a user types an invalid username or password.
    type: boolean
  - IsInternalError:
    description: Specifies that an internal server error happens when finishing the login process.
    type: boolean
required:
  - CSRFToken
  - Challenge
  - LoginURL
  - IsInvalidCredentials
  - IsInternalError

When a login page's template contains static resources (like styles, scripts, and images) they must be placed in a subdirectory called static.

For a full example of a login page's template see source code.

Example

1. Create file ldap.ldif:

   dn: uid=kolya_gerasyimov,ou=Users,dc=example,dc=com
   objectClass: inetOrgPerson
   cn: Kolya Gerasyimov
   sn: Gerasyimov
   uid: kolya_gerasyimov
   userPassword: 123
   mail: kolya_gerasyimov@example.com
   ou: Users
   
   dn: ou=AppRoles,dc=example,dc=com
   objectClass: organizationalunit
   ou: AppRoles
   description: AppRoles
   
   dn: ou=App1,ou=AppRoles,dc=example,dc=com
   objectClass: organizationalunit
   ou: App1
   description: App1
   
   dn: cn=traveler,ou=App1,ou=AppRoles,dc=example,dc=com
   objectClass: groupofnames
   cn: traveler
   description: traveler
   member: uid=kolya_gerasyimov,ou=Users,dc=example,dc=com
   

2. Create file docker-compose.yml:

   version: "3"
   services:
       hydra-client:
           image: oryd/hydra:v1.0.0-rc.12
           environment:
               HYDRA_ADMIN_URL: http://hydra:4445
           command:
               - clients
               - create
               - --skip-tls-verify
               - --id
               - test-client
               - --secret
               - test-secret
               - --response-types
               - id_token,token,"id_token token"
               - --grant-types
               - implicit
               - --scope
               - openid,profile,email,roles
               - --callbacks
               - http://localhost:3000
               - --post-logout-callbacks
               - http://localhost:3000/post-logout-callback
           networks:
               - hydra-net
           deploy:
               restart_policy:
                   condition: none
           depends_on:
               - hydra
           healthcheck:
               test: ["CMD", "curl", "-f", "http://hydra:4445"]
               interval: 10s
               timeout: 10s
               retries: 10
       hydra:
           image: oryd/hydra:v1.0.0-rc.12
           environment:
               URLS_SELF_ISSUER: http://localhost:4444
               URLS_SELF_PUBLIC: http://localhost:4444
               URLS_LOGIN: http://localhost:8080/auth/login
               URLS_CONSENT: http://localhost:8080/auth/consent
               URLS_LOGOUT: http://localhost:8080/auth/logout
               WEBFINGER_OIDC_DISCOVERY_SUPPORTED_SCOPES: profile,email,phone,roles
               WEBFINGER_OIDC_DISCOVERY_SUPPORTED_CLAIMS: name,family_name,given_name,nickname,email,phone_number,https://github.com/i-core/werther/claims/roles
               DSN: memory
           command: serve all --dangerous-force-http
           networks:
               - hydra-net
           ports:
               - "4444:4444"
               - "4445:4445"
           deploy:
               restart_policy:
                   condition: on-failure
           depends_on:
               - werther
       werther:
           image: icoreru/werther:v1.1.1
           environment:
               WERTHER_IDENTP_HYDRA_URL: http://hydra:4445
               WERTHER_LDAP_ENDPOINTS: ldap:389
               WERTHER_LDAP_BINDDN: cn=admin,dc=example,dc=com
               WERTHER_LDAP_BINDPW: password
               WERTHER_LDAP_BASEDN: "dc=example,dc=com"
               WERTHER_LDAP_ROLE_BASEDN: "ou=AppRoles,dc=example,dc=com"
           networks:
               - hydra-net
           ports:
               - "8080:8080"
           deploy:
               restart_policy:
                   condition: on-failure
           depends_on:
               - ldap
       ldap:
           image: pgarrett/ldap-alpine
           volumes:
               - "./ldap.ldif:/ldif/ldap.ldif"
           networks:
               - hydra-net
           ports:
               - "389:389"
           deploy:
               restart_policy:
                   condition: on-failure
   networks:
       hydra-net:
   

3. Run the command:

   docker stack deploy -c docker-compose.yml auth
   

4. Open the browser with http://localhost:4444/oauth2/auth?client_id=test-client&response_type=token&scope=openid%20profile%20email%20roles&state=12345678.

Resources

• Introduction to ORY Hydra, OAuth 2.0, and OpenID Connect;
• ORY Hydra: Integrating with (existing) User Management;
• ORY Hydra: Configuration;
• ORY Hydra: Official User Login & Consent Example;
• OpenID Connect Core 1.0;
• OpenID Connect Session Management 1.0;
• OpenID Connect Front-Channel Logout 1.0;
• OpenID Connect Back-Channel Logout 1.0.

Footnotes

1. Werther is named after robot Werther from Guest from the Future.

Contributing

Thanks for your interest in contributing to this project. Get started with our Contributing Guide.

License

The code in this project is licensed under MIT license.