documentation/tutorials/microsoft.md

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# Microsoft Tutorial

This is a quick tutorial on how to configure Microsoft (Azure AD) authentication.

## Quick setup with Igniter

The fastest way to add Microsoft authentication is with the Igniter generator:

```bash
mix ash_authentication.add_strategy microsoft
```

This creates the UserIdentity resource, register action, secrets wiring, and strategy DSL for you. Follow the printed instructions to register your Azure AD application and set the required environment variables. The rest of this tutorial covers manual setup.

## Manual setup

First you'll need a registered application in the [Microsoft Entra admin center](https://entra.microsoft.com/), in order to get your OAuth 2.0 credentials.

1. Under the **Entra ID** fan click **App registrations**
2. Click **New registration**
3. Enter a name for your application
4. Under **Redirect URI**, select **Web** and enter your callback URL. E.g. `http://localhost:4000/auth/user/microsoft/callback`
5. Click **Register**
6. From the app's **Overview** page, copy the **Application (client) ID** — this is your `client_id`
7. From the same **Overview** page, copy the **Directory (tenant) ID** — you'll need this if you want to restrict sign-in to a specific tenant
8. Navigate to **Certificates & secrets** > **+ New client secret**, add a description and expiry, then copy the secret **Value** — this is your `client_secret`

Next we configure our resource to use Microsoft credentials:

```elixir
defmodule MyApp.Accounts.User do
  use Ash.Resource,
    extensions: [AshAuthentication],
    domain: MyApp.Accounts

  attributes do
    ...
  end

  authentication do
    strategies do
      microsoft do
        client_id MyApp.Secrets
        redirect_uri MyApp.Secrets
        client_secret MyApp.Secrets
      end
    end
  end
end
```

By default the strategy uses the `common` tenant endpoint, which allows any Microsoft
account (personal, work, or school). To restrict sign-in to a specific Azure tenant,
override `base_url`:

```elixir
microsoft do
  client_id MyApp.Secrets
  redirect_uri MyApp.Secrets
  client_secret MyApp.Secrets
  base_url "https://login.microsoftonline.com/YOUR_TENANT_ID/v2.0"
end
```

Please check the [guide](https://hexdocs.pm/ash_authentication/AshAuthentication.Secret.html) on how to properly configure your Secrets.
Then we need to define an action that will handle the oauth2 flow, for the Microsoft case it is `:register_with_microsoft` — it will handle both cases for our resource, user registration & login.

```elixir
defmodule MyApp.Accounts.User do
  require Ash.Resource.Change.Builtins
  use Ash.Resource,
    extensions: [AshAuthentication],
    domain: MyApp.Accounts

  # ...
  actions do
    create :register_with_microsoft do
      argument :user_info, :map, allow_nil?: false
      argument :oauth_tokens, :map, allow_nil?: false
      upsert? true
      upsert_identity :unique_email

      change AshAuthentication.GenerateTokenChange

      # Required if you have the `identity_resource` configuration enabled.
      change AshAuthentication.Strategy.OAuth2.IdentityChange

      change {AshAuthentication.Strategy.OAuth2.UserInfoToAttributes, fields: [:email]}

      # Required if you're using the password & confirmation strategies
      upsert_fields []
      change set_attribute(:confirmed_at, &DateTime.utc_now/0)
    end
  end

  # ...

end
```

Ensure you set the `hashed_password` to `allow_nil?` if you are also using the password strategy.

```elixir
defmodule MyApp.Accounts.User do
  # ...
  attributes do
    # ...
    attribute :hashed_password, :string, allow_nil?: true, sensitive?: true
  end
  # ...
end
```

And generate and run migrations in that case.

```bash
mix ash.codegen make_hashed_password_nullable
mix ash.migrate
```