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https://github.com/smpallen99/coherence

Coherence is a full featured, configurable authentication system for Phoenix
https://github.com/smpallen99/coherence

authentication elixir hex package phoenix-framework

Last synced: 21 days ago
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Coherence is a full featured, configurable authentication system for Phoenix

Host: GitHub
URL: https://github.com/smpallen99/coherence
Owner: smpallen99
License: mit
Created: 2016-07-04T19:47:25.000Z (over 8 years ago)
Default Branch: master
Last Pushed: 2024-08-20T16:24:14.000Z (3 months ago)
Last Synced: 2024-09-30T17:40:54.979Z (about 1 month ago)
Topics: authentication, elixir, hex, package, phoenix-framework
Language: Elixir
Size: 1.05 MB
Stars: 1,267
Watchers: 29
Forks: 223
Open Issues: 73
Metadata Files:
- Readme: README.md
- Changelog: CHANGELOG.md
- Contributing: CONTRIBUTING.md
- License: LICENSE
- Code of conduct: CODE_OF_CONDUCT.md

Awesome Lists containing this project

freaking_awesome_elixir - Elixir - Coherence is a full featured, configurable authentication system for Phoenix. ([Docs](https://hexdocs.pm/coherence/Coherence.html)). (Authentication)
fucking-awesome-elixir - coherence - Coherence is a full featured, configurable authentication system for Phoenix. ([Docs](https://hexdocs.pm/coherence/Coherence.html)). (Authentication)
awesome-elixir - coherence - Coherence is a full featured, configurable authentication system for Phoenix. ([Docs](https://hexdocs.pm/coherence/Coherence.html)). (Authentication)

README

# Coherence

[![Build Status](https://travis-ci.org/smpallen99/coherence.svg?branch=master)](https://travis-ci.org/smpallen99/coherence) [![Hex Version][hex-img]][hex] [![License][license-img]][license]

[hex-img]: https://img.shields.io/hexpm/v/coherence.svg
[hex]: https://hex.pm/packages/coherence
[license-img]: http://img.shields.io/badge/license-MIT-brightgreen.svg
[license]: http://opensource.org/licenses/MIT

Checkout the [Coherence Demo Project](https://github.com/smpallen99/coherence_demo) to see an example project using Coherence.

Coherence is a full featured, configurable authentication system for Phoenix, with the following modules:

* [Database Authenticatable](#authenticatable): handles hashing and storing an encrypted password in the database.
* [Invitable](#invitable): sends invites to new users with a sign-up link, allowing the user to create their account with their own password.
* [Registerable](#registerable): allows anonymous users to register a users email address and password.
* [Confirmable](#confirmable): new accounts require clicking a link in a confirmation email.
* [Recoverable](#recoverable): provides a link to generate a password reset link with token expiry.
* [Trackable](#trackable): saves login statistics like login counts, timestamps, and IP address for each user.
* [Lockable](#lockable): locks an account when a specified number of failed sign-in attempts has been exceeded.
* [Unlockable With Token](#unlockable-with-token): provides a link to send yourself an unlock email.
* [Rememberable](#remember-me): provides persistent login with 'Remember me?' check box on login page.

Coherence provides flexibility by adding namespaced templates and views for only the options specified by the `mix coh.install` command. This boiler plate code is added to your `lib/my_project/web/templates/coherence` and `lib/my_project/web/views/coherence` directories.

Once the boilerplate has been generated, you are free to customize the source as required.

As well, a `lib/my_project/web/coherence_web.ex` is added. Migrations are also generated to add the required database fields.

See the [Docs](https://hexdocs.pm/coherence/Coherence.html) and [Wiki](https://github.com/smpallen99/coherence/wiki) for more information.

## Installation

1. Add coherence to your list of dependencies in `mix.exs`:

```elixir
def deps do
[{:coherence, "~> 0.8"}]
end
```

2. Ensure coherence is started before your application:

```elixir
def application do
extra_applications: [..., :coherence]]
end
```

## Upgrading

After upgrading a Coherence version, you should generate the boilerplate files. To assist this process, use the `--reinstall` option.

This option uses your project's existing coherence config and runs the the installer with the same options.

```shell
mix coh.install --reinstall
```

Run a `git diff` to review the updated files. If you had updated any of the boilerplate files, you may need to manually integrate the changes into the newly generated files.

Run `mix help coh.install` for more information.

## Phoenix & Phx Project Structure

Coherence supports projects created with the older `mix phoenix.new` and the newer `mix phx.new` commands. Separate versions of the mix tasks exist for each project structure.

For projects created with `mix phx.new`, use the following mix tasks:

* `coh.install`
* `coh.clean`

For projects created with `mix phx.new --umbrella`, ensure you are in the app directory and use the following options for the install:
* `cd apps/my_project`
* `coh.install --web-module MyProjectWeb --web-path ../my_project_web/lib/my_project_web`

## Getting Started

First, decide which modules you would like to use for your project. For the following example we are going to use a full install except for the confirmable option.

Run the installer

```bash
$ mix coh.install --full-invitable
```

This will:

* add the coherence configuration to the end of your `config/config.exs` file.
* add a new User model if one does not already exist
* add migration files
* timestamp_add_coherence_to_user.exs if the User model already exists
* timestamp_create_coherence_user.exs if the User model does not exist
* timestamp_create_coherence_invitable.exs
* add view files lib/my_project/web/views/coherence/
* add template files to lib/my_project/web/templates/coherence
* add email files to lib/my_project/web/emails/coherence
* add lib/my_project/web/coherence_web.ex file
* add lib/my_project/web/coherence_messages.ex file

You should review your `config/config.exs` as there are a couple items you will need to customize like email address and mail api_key. If you don't edit the email_from value to something different than its default, emails may not be sent.

See [Installer](#installer) for more install options.

You will need to update a few files manually.

```elixir
# lib/my_project_web/router.ex

defmodule MyProjectWeb.Router do
use MyProjectWeb, :router
use Coherence.Router # Add this

pipeline :browser do
plug :accepts, ["html"]
plug :fetch_session
plug :fetch_flash
plug :protect_from_forgery
plug :put_secure_browser_headers
plug Coherence.Authentication.Session # Add this
end

# Add this block
pipeline :protected do
plug :accepts, ["html"]
plug :fetch_session
plug :fetch_flash
plug :protect_from_forgery
plug :put_secure_browser_headers
plug Coherence.Authentication.Session, protected: true
end

# Add this block
scope "/" do
pipe_through :browser
coherence_routes()
end

# Add this block
scope "/" do
pipe_through :protected
coherence_routes :protected
end

scope "/", MyProjectWeb do
pipe_through :browser

get "/", PageController, :index
# add public resources below
end

scope "/", MyProjectWeb do
pipe_through :protected

# add protected resources below
resources "/privates", MyProjectWeb.PrivateController
end
end
```
**Important**: Note the name-spacing above. Unless you generate coherence controllers, ensure that the scopes, `scope "/" do`, do not include your projects' scope here. If so, the coherence routes will not work!

If the installer created a user schema (one did not already exist), there is nothing you need to do with that generated file. Otherwise, update your existing schema (assuming its `Accounts.User` like this:

```elixir
# lib/my_project/accounts/user.ex

defmodule MyProject.Accounts.User do
use Ecto.Schema
use Coherence.Schema # Add this

schema "users" do
field :name, :string
field :email, :string
coherence_schema() # Add this

timestamps()
end

def changeset(model, params \\ %{}) do
model
|> cast(params, [:name, :email] ++ coherence_fields) # Add this
|> validate_required([:name, :email])
|> validate_format(:email, ~r/@/)
|> validate_coherence(params) # Add this
end

def changeset(model, params, :password) do
model
|> cast(params, ~w(password password_confirmation reset_password_token reset_password_sent_at))
|> validate_coherence_password_reset(params)
end
end
```

An alternative approach is add the authentication plugs to individual controllers that require authentication. You will want to use this approach if you require authentication for a subset of actions in a controller.

For example, lets say you want to show a list of products for everyone visiting the site, but only want authenticated users to be able to create, update, and delete products. You could do the following:

Ensure the following is in your `lib/my_project_web/router.ex` file:

```elixir
scope "/", MyProjectWeb do
pipe_through :browser
resources "/products", ProductController
end
```

In your product controller add the following:

```elixir
defmodule MyProjectWeb.ProductController do
use MyProjectWeb, :controller

plug Coherence.Authentication.Session, [protected: true] when action != :index

# ...
end
```

## Default Configuration

```elixir
{:require_current_password, true}, # Current password is required when updating new password.
{:reset_token_expire_days, 2},
{:confirmation_token_expire_days, 5},
{:allow_unconfirmed_access_for, 0},
{:max_failed_login_attempts, 5},
{:unlock_timeout_minutes, 20},
{:unlock_token_expire_minutes, 5},
{:rememberable_cookie_expire_hours, 2*24},
{:forwarded_invitation_fields, [:email, :name]}
{:allow_silent_password_recovery_for_unknown_user, false},
{:password_hashing_alg, Comeonin.Bcrypt}
```

You can override this default configs. For example: you can add the following codes inside `config/config.exs`

```elixir
config :coherence,
require_current_password: false,
max_failed_login_attempts: 3
```

## Custom registration and sessions routes

Coherence supports custom routes for registration and login. These configurations can be set globally or scoped.

Which routes can be custom?

```
%{
registrations_new: "/registrations/new",
registrations: "/registrations",
passwords: "/passwords",
confirmations: "/confirmations",
unlocks: "/unlocks",
invitations: "/invitations",
invitations_create: "/invitations/create",
invitations_resend: "/invitations/:id/resend",
sessions: "/sessions",
registrations_edit: "/registrations/edit"
}
```

To set them globally add the following to you configuration:

```elixir
config :coherence,
default_routes: %{
registrations_edit: "/accounts/edit", ...},
```

To set them scoped for each mode (protected, public, etc..):

```elixir
scope "/" do
pipe_through :protected
coherence_routes :protected, [
custom_routes: %{registratons_edit: "/accounts/edit", ...}
]
end
```

## Phoenix Channel Authentication

Coherence supports channel authentication using `Phoenix.Token`. To enable channel authentication do the following:

Add the following option to coherence configuration.

```elixir
config :coherence,
user_token: true
```

Update your socket module:

```elixir
defmodule MyProjectWeb.UserSocket do
use Phoenix.Socket

def connect(%{"token" => token}, socket) do
case Coherence.verify_user_token(socket, token, &assign/3) do
{:error, _} -> :error
{:ok, socket} -> {:ok, socket}
end
end
end
```

## Localization with Gettext

Coherence supports `Gettext` for all User facing messages. Your project's `Gettext` module is used by default.

All Coherence messages use `dgettext` with the `"coherence"` domain. This means that after you run `mix gettext.extract`, you will see `coherence.pot` files generated. Running `mix gettext.merge priv/gettext` will generate the corresponding `coherence.po` files.

Coherence does not come with pre-translated `.po` files. We figure that you will want to tweak the Coherence language to suite your application.

All files added to your project with the Coherence generators include a `import MyProjectWeb.Gettext` with the `"coherence"` domain.

The other messages that Coherence uses internal are pulled from the `my_project_web/coherence_messages.ex` file that is generated with the `coh.install` mix task. You can edit this file and customize it as required.

To assist in upgrades to future releases of Coherence, the `MyProject.Coherence.Messages` module uses the `Coherence.Messages` behaviour which defines each message function. So, if you miss a message after upgrading, you will see a message during compile time.

## Option Overview

### Authenticatable

Handles hashing and storing an encrypted password in the database.

Provides `/sessions/new` and `/sessions/delete` routes for logging in and out with
the appropriate templates and view.

The following columns are added the `_add_coherence_to_user.exs` migration:

* :password_hash, :string - the encrypted password

### Invitable

Handles sending invites to new users with a sign-up link, allowing the user to create their account with their own password.

Provides `/invitations/new` and `invitations/edit` routes for creating a new invitation and creating a new account from the invite email.

These routes can be configured to require login by using the `coherence_routes :private` macro in your router.exs file.

Invitation token timeout will be added in the future.

The following table is created by the generated `_create_coherence_invitable.exs` migration:

```elixir
create table(:invitations) do
add :name, :string
add :email, :string
add :token, :string
end
```

### Registerable

Allows anonymous users to register a users email address and password.

Provides `/registrations/new`, `create`, `edit`, `update`, `show`, and `delete` routes for managing registrations.

Adds the following:

* `Register New Account` to the log-in page.
* `Link to account page on layout helpers`
* Show page with `edit` and `delete` links
* `edit` page

It is recommended that the :confirmable option is used with :registerable to
ensure a valid email address is captured.

### Confirmable

Requires a new account be confirmed. During registration, a confirmation token is generated and sent to the registering email. This link must be clicked before the user can sign-in.

Provides `edit` action for the `/confirmations` route.

The confirmation token expiry default of 5 days can be changed with the `:confirmation_token_expire_days` config entry.

### Recoverable

Allows users to reset their password using an expiring token send by email.

Provides `new`, `create`, `edit`, `update` actions for the `/passwords` route.

Adds a "Forgot your password?" link to the log-in form. When clicked, the user provides their email address and if found, sends a reset password instructions email with a reset link.

The expiry timeout can be changed with the `:reset_token_expire_days` config entry.

By default, providing an unknown email address will result in a form error. If you want to prevent that and display a confirmation message even if the email isn’t found, set the `:allow_silent_password_recovery_for_unknown_user` to `true`.

### Trackable

Saves login statistics like login counts, timestamps, and IP address for each user.

Adds the following database field to your User model with the generated migration:

```elixir
add :sign_in_count, :integer, default: 0 # how many times the user has logged in
add :current_sign_in_at, :datetime # the current login timestamp
add :last_sign_in_at, :datetime # the timestamp of the previous login
add :current_sign_in_ip, :string # the current login IP adddress
add :last_sign_in_ip, :string # the IP address of the previous login
```

### Lockable

Locks an account when a specified number of failed sign-in attempts has been exceeded.

The following defaults can be changed with the following config entries:

* `:unlock_timeout_minutes`
* `:max_failed_login_attempts`

Adds the following database field to your User model with the generated migration:

```elixir
add :failed_attempts, :integer, default: 0
add :unlock_token, :string
add :locked_at, :datetime
```

### Unlockable with Token

Provides a link to send yourself an unlock email. When the user clicks the link, the user is presented a form to enter their email address and password. If the token has not expired and the email and password are valid, a unlock email is sent to the user's email address with an expiring token.

The default expiry time can be changed with the `:unlock_token_expire_minutes` config entry.

### Remember Me

The `rememberable` option provides persistent login when the 'Remember Me?' box is checked during login.

With this feature, you will automatically be logged in from the same browser when your current login session dies using a configurable expiring persistent cookie.

For security, both a token and series number stored in the cookie on initial login. Each new creates a new token, but preserves the series number, providing protection against fraud. As well, both the token and series numbers are hashed before saving them to the database, providing protection if the database is compromised.

The following defaults can be changed with the following config entries:

* :rememberable_cookie_expire_hours (2\*24)
* :login_cookie ("coherence_login")

The following table is created by the generated `_create_coherence_rememberable.exs` migration:

```elixir
create table(:rememberables) do
add :series_hash, :string
add :token_hash, :string
add :token_created_at, :datetime
add :user_id, references(:users, on_delete: :delete_all)

timestamps
end

create index(:rememberables, [:user_id])
create index(:rememberables, [:series_hash])
create index(:rememberables, [:token_hash])
create unique_index(:rememberables, [:user_id, :series_hash, :token_hash])
```

The `--rememberable` install option is not provided in any of the installer group options. You must provide the `--rememberable` option to install the migration and its support.

### User Active Field

The `--user-active-field` option can be given to the installer to support inactive users. When a user is set as inactive, they will not be able to login.

Using this option adds a `active` field to the user schema with a default of `true`.

## Mix Tasks

### Installer

The following examples illustrate various configuration scenarios for the install mix task:

```bash
# Install with only the `authenticatable` option
$ mix coh.install

# Install all the options except `confirmable` and `invitable`
$ mix coh.install --full

# Install all the options except `invitable`
$ mix coh.install --full-confirmable

# Install all the options except `confirmable`
$ mix coh.install --full-invitable

# Install the `full` options except `lockable` and `trackable`
$ mix coh.install --full --no-lockable --no-trackable
```

And some reinstall examples:

```bash
# Reinstall with defaults (--silent --no-migrations --no-config --confirm-once)
$ mix coh.install --reinstall

# Confirm to overwrite files, show instructions, and generate migrations
$ mix coh.install --reinstall --no-confirm-once --with-migrations
```

Run `$ mix help coh.install` for more information.

### Clean

The following examples illustrate how to remove the files created by the installer:

```bash
# Clean all the installed files
$ mix coh.clean --all

# Clean only the installed view and template files
$ mix coh.clean --views --templates

# Clean all but the models
$ mix coh.clean --all --no-models

# Prompt once to confirm the removal
$ mix coh.clean --all --confirm-once
```

After installation, if you later want to remove one more options, here are a couple examples:

```bash
# Clean one option
$ mix coh.clean --options=recoverable

# Clean several options without confirmation
$ mix coh.clean --no-confirm --options="recoverable unlockable-with-token"

# Test the uninstaller without removing files
$ mix coh.clean --dry-run --options="recoverable unlockable-with-token"
```

## Customization

The `coh.install` mix task generates a bunch of boiler plate code so you can easily customize the views, templates, and mailer.

Also, checkout the Coherence.Config module for a list of config items you can use to tune the behaviour of Coherence.

### Custom Controllers

By default, controller boilerplate is not generated. To add controllers, use the controller generators.

* For phx projects, use the `mix coh.gen.controllers` task.

The generated controllers are named `MyProjectWeb.Coherence.SessionController` as an example. Generated controllers are located in `lib/my_project_web/controllers/coherence/`

If the controllers are generated, you will need to change your router to use the new names. For example:

```elixir
# lib/my_project_web/router.ex

defmodule MyProjectWeb.Router do
use MyProjectWeb, :router
use Coherence.Router

# ...

scope "/", MyProjectWeb do # note the addition of MyProjectWeb
pipe_through :public
coherence_routes()
end

scope "/", MyProjectWeb do # note the addition of MyProjectWeb
pipe_through :browser
coherence_routes :protected
end

# ...
end
```

As of Coherence v0.6.0, the generated controller modules have very little code. All the controller actions and helper functions are included with a `use xxxControllerBase` call.

To change an action, simply define the appropriate function and add your own implementation. You may want to copy over the implementation found in your projects `deps/coherence/lib/coherence/controllers/xxx_controller_base.ex` file as a starting point and customize it as needed.

Alternatively, if can create the action, handle some specify behavior and call `super(conn, params)` so invoke the default action. Depending on your customization, this may be the best approach since its easier to see how changes when upgrading to new versions of Coherence.

### Customizing Routes

By default, Coherence assumes you want all available routes for the `opts` you've configured. However, you can specify which routes should be available by modifying your configuration.

For example, if you want all of the routes for `authenticatable`, but only the `new` and `create` actions from `registerable`:

```elixir
# config/config.exs
config :coherence,
# ...
opts: [:authenticatable, registerable: [:new, :create]]
```

### Customizing Redirections

Many of the controller actions redirect the user after create and update actions. These redirections can be customized by adding function call backs in the `lib/my_project_web/controllers/coherence/redirect.ex` module that is generated by the `mix coh.install` task.

For example, to have the user redirected to the login screen after logging out at the following:

```elixir
defmodule Coherence.Redirects do
use Redirects
import MyProjectWeb.Router.Helpers

# override the log out action back to the log in page
def session_delete(conn, _), do: redirect(conn, session_path(conn, :new))
end
```

See the documentation for further details.

### Customizing Responders

To customize how application responds to html or json format, you can override methods in the `lib/my_project_web/controllers/coherence/responders/html.ex` or `lib/my_project_web/controllers/coherence/responders/json.ex`.

### Customizing layout

By default coherence uses its own layout which is installed to `lib/my_project_web/templates/coherence/layout/app.html.eex`.

If you want to customize coherence controllers layout, you can follow different approaches:

* Edit the generated layout at `lib/my_project_web/templates/coherence/layout/app.html.eex`.
* Set `:layout` in your config file. e.g. `config :coherence, :layout, {MyProjectWeb.LayoutView, :app}`
* Install coherence controllers to application and edit them, to use layout module different from `Coherence.LayoutView`
* And the last solution is to use `plug :put_layout` in your `lib/my_project_web/router.ex` file. For example:

```elixir
defmodule MyProjectWeb.Router do
# ...
pipeline :coherence do
plug :put_layout, {MyProjectWeb.LayoutView, :app}
end
# ...
scope "/" do
pipe_through [:protected, :coherence]
coherence_routes :protected
end
#...
end
```

## Customizing User Changeset

The User model changeset used by Coherence can be customized for each Coherence controller. To customize the changeset, set the `changeset` config option.

For example, the following defines a changeset/3 function in your user model:

```elixir
# config/config.exs
config :coherence,
# ...
changeset: {MyProject.User, :changeset}
```

Now add a new `changeset/3` function to the user model. The following example defines a custom changeset for the registration controller:

```elixir
# lib/coherence/coherence/user.ex
defmodule CoherenceDemo.User do
use Ecto.Schema
use Coherence.Schema

# ...

def changeset(model, params \\ %{}) do
model
|> cast(params, [:name, :email] ++ coherence_fields)
|> validate_required([:name, :email])
|> validate_format(:email, ~r/@/)
|> unique_constraint(:email)
|> validate_coherence(params)
end
def changeset(model, params, :registration) do
# custom changeset for registration controller
model
|> cast(params, [:name, :email] ++ coherence_fields)
|> validate_required([:name, :email])
|> validate_format(:email, ~r/@/)
|> unique_constraint(:email)
|> validate_coherence(params)
end
def changeset(model, params, _which) do
# use the default changeset for all other coherence controllers
changeset model, params
end
end
```

When a custom changeset is configured, the changeset function is called with an atom indicating the controller calling the changeset, allowing you to match on specific controllers.

The list of controller actions are:

* :confirmation
* :invitation
* :password
* :registration
* :session
* :unlock

## Customizing Password Hashing Algorithm

Coherence uses the `Bcrypt` algorithm by default for hashing passwords. However, with the update to Comeonin 4.0, you can now change the hashing algorithm.

Comeonin currently supports the following 3 algorithms:

* [Argon2](https://github.com/riverrun/argon2_elixir)
* [Bcrypt](https://github.com/riverrun/bcrypt_elixir)
* [Pbkdf2](https://github.com/riverrun/pbkdf2_elixir)

### Change the Hashing Algorithm in an Existing Project

To change the default in an existing project (to Argon2 for example), make the following 2 changes:

* Edit your `config/config.exs` file add/change the following line:

```elixir
# config/config.exs
config :coherence,
# ...
password_hashing_alg: Comeonin.Argon2,
# ...
```

* add the dependency to `mix.exs`

```elixir
# mix.exs
defp deps do
[
# ...
{:argon2_elixir, "~> 1.3"}
]
end
```

### Change the Hashing Algorithm in an Existing Project

To install Coherence in a new project with the `Pbkdf2` hashing algorithm (with the --full option for example):

```bash
# mix coh.install --full --password-hashing-alg=Comeonin.Argon2
```

and add the dependency

```elixir
# mix.exs
defp deps do
[
# ...
{:pbkdf2_elixir, "~> 0.12"}
]
end
```

### Speed up Tests and Database Seeding of Users

The default hashing algorithms are setup for production use. They are very slow by design which can cause very slow tests and database seeding in the dev and test environments. To speed this up, you can add the following to you `config/dev.exs` and/or `config/test.exs` configuration.

However, *DON'T USE THESE SETTINGS IN PRODUCTION*

```elixir
# config/test.exs
config :argon2_elixir,
t_cost: 1,
m_cost: 8
config :bcrypt_elixir, log_rounds: 4
config :pbkdf2_elixir, rounds: 1
```

Note: Only configure the algorithm you have configured!

## Accessing the Currently Logged In User

During login, a current version of the user model is cashed in the credential store. During each authentication request, the user model is fetched from the credential store and placed in conn.assigns[:current_user] to avoid a database fetch on each request.

You can access the current user's name in a template like this:

```elixir
<%= Coherence.current_user_name(@conn) %>
```

Any of the user model's available data can be accessed this way.

## Updating the User Model

If the user model is changed after login, a call to `update_login` must be done to update the credential store. For example, in your controller update function, call:

```elixir
Coherence.update_user_login(conn, user)
```

to update the credential store.

This is not needed for registration update page.

## Configuring the Swoosh Email Adapter

The following configuration must be setup to send emails:

```elixir
config :coherence,
email_from_name: "Some Name",
email_from_email: "[email protected]"

config :coherence, CoherenceDemoWeb.Coherence.Mailer,
adapter: Swoosh.Adapters.Sendgrid,
api_key: "SENDGRID_API_KEY"
```

You may want to configure the email system to use system environment variables.

```elixir
config :coherence,
email_from_name: {:system, "NAME"},
email_from_email: {:system, "EMAIL"}

config :coherence, CoherenceDemoWeb.Coherence.Mailer,
api_key: {:system, "SENDGRID_API_KEY"}
```

## Permitted Attributes

For security, Coherence restricts what fields of a schema can be created or
updated with several configurable permitted attributes settings. When installing
a new project these settings are generated in the `:coherence` Config block.

In the case of an upgrade, the following values will be used when the configuration
is not found:

| Configuration Field | Defaults |
| --- | --- |
| `:registration_permitted_attributes` | ["email","name","password", "current_password", "password_confirmation"] |
| `:invitation_permitted_attributes` | ["name","email"] |
| `:password_reset_permitted_attributes` | ["reset_password_token","password", "password_confirmation"] |
| `:session_permitted_attributes` | ["remember","email","password"] |

## Authentication

Currently Coherence supports three modes of authentication including HTTP Basic, Session, and Token authentication.

For HTTP Basic and Token authentication, you will need to add the credentials into the Credential Store. This is not required for Session or IpAddress Authentication.

IpAddress authentication is a good solution for server to server rest APIs.

### Add HTTP Basic Credentials Example

```elixir
creds = Coherence.Authentication.Basic.encode_credentials("Admin", "SecretPass")
Coherence.CredentialStore.Server.put_credentials(creds, %{id: "USER_ID_HERE", role: :admin})
```

### Add Token Credentials Example

```elixir
token = Coherence.Authentication.Token.generate_token
Coherence.CredentialStore.Server.put_credentials(token, %{id: "USER_ID_HERE", role: :admin})
```

### Add IP Credentials Example

```elixir
Coherence.CredentialStore.Server.put_credentials({127,0,0,1}, %{id: "USER_ID_HERE", role: :admin})
```

IpAddress authentication does not require this step. Its optional. If the user_data
is not found in the credential store, the conn.assigns will not be set.

To add authentication, use on of the following three:

### HTTP Basic Plug Example

```elixir
plug Coherence.Authentication.Basic, realm: "Secret"
```

The realm parameter is optional and can be omitted. By default "Restricted Area" will be used as realm name. You can also pass the error parameter, which should be a string or a function. If a string is passed, that string will be sent instead of the default message "HTTP Authentication Required" on authentication failure (with status code 401). If a function is passed, that function will be called with one argument, `conn`.

### Token Plug Example

```elixir
plug Coherence.Authentication.Token, source: :params, param: "auth_token", error: ~s'{"error":"authentication required"}'
```

The error parameter is optional and is treated as in the example above. The source parameter defines how to retrieve the token from the connection. Currently, the three acceptable values are: `:params`, `:header` and `:session`. Their name is self-explainatory. The param parameter defines the name of the parameter/HTTP header/session key where the token is stored. This should cover most cases, but if retrieving the token is more complex than that, you can pass a tuple for the source parameter. The tuple must be in the form `{MyModule, :my_function, ["param1", 42]}`. The function must accept a connection as its first argument (which will be injected as the head of the given parameter list) and any other number of parameters, which must be given in the third element of the tuple. If no additional arguments are needed, an empty list must be given.

### Session Plug Example

```elixir
plug Coherence.Authentication.Session, cookie_expire: 10*60*60, login: &MyController.login/1, assigns_key: :authenticated_user
```

The `:cookie_expire` value the expire time in seconds. The `:login` is a fun that will be passed `conn` if the user is not logged in. Use the `:assigns_key` to change the default `:current_user` value.

Note that if you provide a login callback, that you must return `halt conn` a the end of the function.

### IP Address Plug Example

```elixir
plug Coherence.Authentication.IpAddress, allow: ~w(127.0.0.1 192.168.1.0/24)
plug Coherence.Authentication.IpAddress, allow: ~w(0.0.0.0/0), deny: ~w(127.0.0.1)
```

The first example will allow local host and any ip address in the subnet 192.168.1.0/255.255.255.0

The second example allows any ip except for localhost.

## Authorization

Coherence is a user management and authentication solution. Support for authorization (access control) can be achieved using another package like [Canary](https://github.com/cpjk/canary).

For an example of using [Canary](https://github.com/cpjk/canary) with Coherence, please visit the [CoherenceDemo canary branch](https://github.com/smpallen99/coherence_demo/tree/canary).

## Contributing

We appreciate any contribution to Coherence. Check our [CODE_OF_CONDUCT.md](CODE_OF_CONDUCT.md) and [CONTRIBUTING.md](CONTRIBUTING.md) guides for more information. We usually keep a list of features and bugs [in the issue tracker][1].

## References

* Detailed Example [Coherence Demo](https://github.com/smpallen99/coherence_demo)
* [Docs](https://hexdocs.pm/coherence/)

[1]: https://github.com/smpallen99/coherence/issues

## License

The source is released under the MIT License.

Check [LICENSE](LICENSE) for more information.