Auth live new mod2

config/config.exs

@@ -7,6 +7,19 @@
 # General application configuration
 import Config
 
+config :myapp18, :scopes,
+  user: [
+    default: true,
+    module: Myapp18.Accounts.Scope,
+    assign_key: :current_scope,
+    access_path: [:user, :id],
+    schema_key: :user_id,
+    schema_type: :id,
+    schema_table: :users,
+    test_data_fixture: Myapp18.AccountsFixtures,
+    test_login_helper: :register_and_log_in_user
+  ]
+
 config :myapp18,
   ecto_repos: [Myapp18.Repo],
   generators: [timestamp_type: :utc_datetime]

config/test.exs

@@ -1,5 +1,8 @@
 import Config
 
+# Only in tests, remove the complexity from the password hashing algorithm
+config :bcrypt_elixir, :log_rounds, 1
+
 # Configure your database
 #
 # The MIX_TEST_PARTITION environment variable can be used

lib/myapp18/accounts.ex

@@ -0,0 +1,308 @@
+defmodule Myapp18.Accounts do
+  @moduledoc """
+  The Accounts context.
+  """
+
+  import Ecto.Query, warn: false
+  alias Myapp18.Repo
+
+  alias Myapp18.Accounts.{User, UserToken, UserNotifier}
+
+  ## Database getters
+
+  @doc """
+  Gets a user by email.
+
+  ## Examples
+
+      iex> get_user_by_email("foo@example.com")
+      %User{}
+
+      iex> get_user_by_email("unknown@example.com")
+      nil
+
+  """
+  def get_user_by_email(email) when is_binary(email) do
+    Repo.get_by(User, email: email)
+  end
+
+  @doc """
+  Gets a user by email and password.
+
+  ## Examples
+
+      iex> get_user_by_email_and_password("foo@example.com", "correct_password")
+      %User{}
+
+      iex> get_user_by_email_and_password("foo@example.com", "invalid_password")
+      nil
+
+  """
+  def get_user_by_email_and_password(email, password)
+      when is_binary(email) and is_binary(password) do
+    user = Repo.get_by(User, email: email)
+    if User.valid_password?(user, password), do: user
+  end
+
+  @doc """
+  Gets a single user.
+
+  Raises `Ecto.NoResultsError` if the User does not exist.
+
+  ## Examples
+
+      iex> get_user!(123)
+      %User{}
+
+      iex> get_user!(456)
+      ** (Ecto.NoResultsError)
+
+  """
+  def get_user!(id), do: Repo.get!(User, id)
+
+  ## User registration
+
+  @doc """
+  Registers a user.
+
+  ## Examples
+
+      iex> register_user(%{field: value})
+      {:ok, %User{}}
+
+      iex> register_user(%{field: bad_value})
+      {:error, %Ecto.Changeset{}}
+
+  """
+  def register_user(attrs) do
+    %User{}
+    |> User.email_changeset(attrs)
+    |> Repo.insert()
+  end
+
+  ## Settings
+
+  @doc """
+  Checks whether the user is in sudo mode.
+
+  The user is in sudo mode when the last authentication was done no further
+  than 20 minutes ago. The limit can be given as second argument in minutes.
+  """
+  def sudo_mode?(user, minutes \\ -20)
+
+  def sudo_mode?(%User{authenticated_at: ts}, minutes) when is_struct(ts, DateTime) do
+    DateTime.after?(ts, DateTime.utc_now() |> DateTime.add(minutes, :minute))
+  end
+
+  def sudo_mode?(_user, _minutes), do: false
+
+  @doc """
+  Returns an `%Ecto.Changeset{}` for changing the user email.
+
+  See `Myapp18.Accounts.User.email_changeset/3` for a list of supported options.
+
+  ## Examples
+
+      iex> change_user_email(user)
+      %Ecto.Changeset{data: %User{}}
+
+  """
+  def change_user_email(user, attrs \\ %{}, opts \\ []) do
+    User.email_changeset(user, attrs, opts)
+  end
+
+  @doc """
+  Updates the user email using the given token.
+
+  If the token matches, the user email is updated and the token is deleted.
+  """
+  def update_user_email(user, token) do
+    context = "change:#{user.email}"
+
+    with {:ok, query} <- UserToken.verify_change_email_token_query(token, context),
+         %UserToken{sent_to: email} <- Repo.one(query),
+         {:ok, _} <- Repo.transaction(user_email_multi(user, email, context)) do
+      :ok
+    else
+      _ -> :error
+    end
+  end
+
+  defp user_email_multi(user, email, context) do
+    changeset = User.email_changeset(user, %{email: email})
+
+    Ecto.Multi.new()
+    |> Ecto.Multi.update(:user, changeset)
+    |> Ecto.Multi.delete_all(:tokens, UserToken.by_user_and_contexts_query(user, [context]))
+  end
+
+  @doc """
+  Returns an `%Ecto.Changeset{}` for changing the user password.
+
+  See `Myapp18.Accounts.User.password_changeset/3` for a list of supported options.
+
+  ## Examples
+
+      iex> change_user_password(user)
+      %Ecto.Changeset{data: %User{}}
+
+  """
+  def change_user_password(user, attrs \\ %{}, opts \\ []) do
+    User.password_changeset(user, attrs, opts)
+  end
+
+  @doc """
+  Updates the user password.
+
+  Returns the updated user, as well as a list of expired tokens.
+
+  ## Examples
+
+      iex> update_user_password(user, %{password: ...})
+      {:ok, %User{}, [...]}
+
+      iex> update_user_password(user, %{password: "too short"})
+      {:error, %Ecto.Changeset{}}
+
+  """
+  def update_user_password(user, attrs) do
+    user
+    |> User.password_changeset(attrs)
+    |> update_user_and_delete_all_tokens()
+    |> case do
+      {:ok, user, expired_tokens} -> {:ok, user, expired_tokens}
+      {:error, :user, changeset, _} -> {:error, changeset}
+    end
+  end
+
+  ## Session
+
+  @doc """
+  Generates a session token.
+  """
+  def generate_user_session_token(user) do
+    {token, user_token} = UserToken.build_session_token(user)
+    Repo.insert!(user_token)
+    token
+  end
+
+  @doc """
+  Gets the user with the given signed token.
+
+  If the token is valid `{user, token_created}` is returned, otherwise `nil` is returned.
+  """
+  def get_user_by_session_token(token) do
+    UserToken.valid_user_session_query(token)
+    |> Repo.one()
+  end
+
+  @doc """
+  Gets the user with the given magic link token.
+  """
+  def get_user_by_magic_link_token(token) do
+    with {:ok, query} <- UserToken.verify_magic_link_token_query(token),
+         {user, _token} <- Repo.one(query) do
+      user
+    else
+      _ -> nil
+    end
+  end
+
+  @doc """
+  Logs the user in by magic link.
+
+  There are three cases to consider:
+
+  1. The user has already confirmed their email. They are logged in
+     and the magic link is expired.
+
+  2. The user has not confirmed their email and no password is set.
+     In this case, the user gets confirmed, logged in, and all tokens -
+     including session ones - are expired. In theory, no other tokens
+     exist but we delete all of them for best security practices.
+
+  3. The user has not confirmed their email but a password is set.
+     This cannot happen in the default implementation but may be the
+     source of security pitfalls. See the "Mixing magic link and password registration" section of
+     `mix help phx.gen.auth`.
+  """
+  def login_user_by_magic_link(token) do
+    {:ok, query} = UserToken.verify_magic_link_token_query(token)
+
+    case Repo.one(query) do
+      # Prevent session fixation attacks by disallowing magic links for unconfirmed users with password
+      {%User{confirmed_at: nil, hashed_password: hash}, _token} when not is_nil(hash) ->
+        raise """
+        magic link log in is not allowed for unconfirmed users with a password set!
+
+        This cannot happen with the default implementation, which indicates that you
+        might have adapted the code to a different use case. Please make sure to read the
+        "Mixing magic link and password registration" section of `mix help phx.gen.auth`.
+        """
+
+      {%User{confirmed_at: nil} = user, _token} ->
+        user
+        |> User.confirm_changeset()
+        |> update_user_and_delete_all_tokens()
+
+      {user, token} ->
+        Repo.delete!(token)
+        {:ok, user, []}
+
+      nil ->
+        {:error, :not_found}
+    end
+  end
+
+  @doc ~S"""
+  Delivers the update email instructions to the given user.
+
+  ## Examples
+
+      iex> deliver_user_update_email_instructions(user, current_email, &url(~p"/users/settings/confirm-email/#{&1}"))
+      {:ok, %{to: ..., body: ...}}
+
+  """
+  def deliver_user_update_email_instructions(%User{} = user, current_email, update_email_url_fun)
+      when is_function(update_email_url_fun, 1) do
+    {encoded_token, user_token} = UserToken.build_email_token(user, "change:#{current_email}")
+
+    Repo.insert!(user_token)
+    UserNotifier.deliver_update_email_instructions(user, update_email_url_fun.(encoded_token))
+  end
+
+  @doc ~S"""
+  Delivers the magic link login instructions to the given user.
+  """
+  def deliver_login_instructions(%User{} = user, magic_link_url_fun)
+      when is_function(magic_link_url_fun, 1) do
+    {encoded_token, user_token} = UserToken.build_email_token(user, "login")
+    Repo.insert!(user_token)
+    UserNotifier.deliver_login_instructions(user, magic_link_url_fun.(encoded_token))
+  end
+
+  @doc """
+  Deletes the signed token with the given context.
+  """
+  def delete_user_session_token(token) do
+    Repo.delete_all(UserToken.by_token_and_context_query(token, "session"))
+    :ok
+  end
+
+  ## Token helper
+
+  defp update_user_and_delete_all_tokens(changeset) do
+    %{data: %User{} = user} = changeset
+
+    with {:ok, %{user: user, tokens_to_expire: expired_tokens}} <-
+           Ecto.Multi.new()
+           |> Ecto.Multi.update(:user, changeset)
+           |> Ecto.Multi.all(:tokens_to_expire, UserToken.by_user_and_contexts_query(user, :all))
+           |> Ecto.Multi.delete_all(:tokens, fn %{tokens_to_expire: tokens_to_expire} ->
+             UserToken.delete_all_query(tokens_to_expire)
+           end)
+           |> Repo.transaction() do
+      {:ok, user, expired_tokens}
+    end
+  end
+end

lib/myapp18/accounts/scope.ex

@@ -0,0 +1,33 @@
+defmodule Myapp18.Accounts.Scope do
+  @moduledoc """
+  Defines the scope of the caller to be used throughout the app.
+
+  The `Myapp18.Accounts.UserScope` allows public interfaces to receive
+  information about the caller, such as if the call is initiated from an
+  end-user, and if so, which user. Additionally, such a scope can carry fields
+  such as "super user" or other privileges for use as authorization, or to
+  ensure specific code paths can only be access for a given scope.
+
+  It is useful for logging as well as for scoping pubsub subscriptions and
+  broadcasts when a caller subscribes to an interface or performs a particular
+  action.
+
+  Feel free to extend the fields on this struct to fit the needs of
+  growing application requirements.
+  """
+
+  alias Myapp18.Accounts.User
+
+  defstruct user: nil
+
+  @doc """
+  Creates a scope for the given user.
+
+  Returns nil if no user is given.
+  """
+  def for_user(%User{} = user) do
+    %__MODULE__{user: user}
+  end
+
+  def for_user(nil), do: nil
+end