Form Auth Scheme (aka Form based Auth)

aah provides an easy to use form-based auth. Three steps are involved in making use of Form auth scheme -

  • Implement authc.Authenticator to provide subject’s authentication info
  • Implement authz.Authorizer to provide subject’s roles and permissions
  • Configure form auth URLs as needed

Refer aah Form Auth example.

Table of Contents

Configuration

aah supports one or more form auth schemes such as using datasource, Active Directory, REST APIs, etc.

Section: form_scheme_key { … }

form_scheme_key { ... } configuration goes under section security.auth_schemes { ... }. 

# -----------------------------------------------------------------------------
# Form auth scheme
# Choose a unique key name. It gets used as route auth.
#
# Doc: https://docs.aahframework.org/auth-schemes/form.html
# -----------------------------------------------------------------------------
form_scheme_key {
  # Auth scheme name.
  # Supported values are `form`, `oauth2`, `basic` and `generic`.
  #
  # It is required value, no default.
  scheme = "form"

  # To provide subject's authentication info during a login flow, implement
  # interface `authc.Authenticator` and configure here. aah validates the
  # credential using configured password encoder.
  #
  # It is required value, no default.
  authenticator = "security/AuthenticationProvider"

  # To provide subject's Roles and Permissions, implement interface
  # `authz.Authorizer` and configure here.
  #
  # It is required value, no default.
  authorizer = "security/AuthorizationProvider"

  # Password encoder is used to configure password algorithm. aah validates
  # subject credentials with application provided credentials.
  #
  # Doc: https://docs.aahframework.org/password-encoders.html
  #
  # Default value is `bcrypt`.
  password_encoder = "bcrypt"

  # Configure field names to extract `AuthenticationToken`
  # from the HTTP request.
  field {
    # Default value is `username`
    identity = "username"

    # Default value is `password`
    credential = "password"
  }

  # Configure form auth scheme URLs such as login page URL, login submit URL,
  # login failure URL and default target URL.
  url {
    # Login page URL.
    # Default value is `/login.html`.
    login = "/login.html"

    # Login submit URL, used to submit login credential for authentication via
    # POST request.
    #
    # Route name is derived from the user-defined auth scheme key.
    # For example:
    # auth scheme key ~ `form_auth` then route name => `form_auth_login_submit__aah`.
    # On login page -
    #   `<form method="post" action="{{ rurl . "form_auth_login_submit__aah" }}">`
    #
    # Default value is `/login`.
    login_submit = "/login"

    # Login failure URL, on failure during authentication process, aah
    # sends the user to this URL.
    #
    # Default value is `/login.html?error=true`.
    login_failure = "/login.html?error=true"

    # By default, aah redirects the user to the requested page after successful
    # authentication; otherwise, aah sends the user to this URL.
    #
    # Default value is `/`.
    default_target = "/"

    # Always redirects to `default_target` URL regardless of the requested page/URL.
    #
    # Default value is `false`.
    always_to_default = false
  }
}

Auto Semantic Route Configuration

Since v0.11.0 aah does auto semantic route configuration of route login submit for all domains provided auth scheme form is configured in it.

  • aah scans security.auth_schemes { ... } to see whether auth scheme form is configured for the domain
  • If configured, then aah automatically adds route <auth-scheme-name>_login_submit__aah to the domain
  • If user configures the route <auth-scheme-name>_login_submit__aah, then aah will not add it. In other words, it will be overridden
  • In view files, form action URL can be accessed as {{ rurl . "<auth-scheme-name>_login_submit__aah" }}

Example Config: form_auth

Configuration from aah Form Auth example. 

# -----------------------------------------------------------------------------
# Form auth scheme
# Choose a unique key name. It gets used as route auth.
#
# Doc: https://docs.aahframework.org/auth-schemes/form.html
# -----------------------------------------------------------------------------
form_auth {
  scheme = "form"
  authenticator = "security/FormAuthenticationProvider"
  authorizer = "security/FormAuthorizationProvider"
}

Auto Semantic route added as - 

form_auth_login_submit__aah {
  # path value form `security.auth_schemes.form_auth.url.login_submit`
  path = "/login"
  method = "POST"
  auth = "form_auth"
  # max_body_size value from `request.max_body_size`
  max_body_size = "5mb"
}

On view file, form action URL accessed as - 

<form method="post" action="{{ rurl . "form_auth_login_submit__aah" }}">