After "mix phx.gen.auth Admins Admin admins" with added working register and login path.

lib/beet_round_server/admins/admin.ex

@@ -0,0 +1,134 @@
+defmodule BeetRoundServer.Admins.Admin do
+  use Ecto.Schema
+  import Ecto.Changeset
+
+  @primary_key {:id, :binary_id, autogenerate: true}
+  @foreign_key_type :binary_id
+  schema "admins" do
+    field :email, :string
+    field :password, :string, virtual: true, redact: true
+    field :hashed_password, :string, redact: true
+    field :confirmed_at, :utc_datetime
+    field :authenticated_at, :utc_datetime, virtual: true
+
+    timestamps(type: :utc_datetime)
+  end
+
+  @doc """
+  A admin changeset for registering or changing the email.
+
+  It requires the email to change otherwise an error is added.
+
+  ## Options
+
+    * `:validate_unique` - Set to false if you don't want to validate the
+      uniqueness of the email, useful when displaying live validations.
+      Defaults to `true`.
+  """
+  def email_changeset(admin, attrs, opts \\ []) do
+    admin
+    |> cast(attrs, [:email])
+    |> validate_email(opts)
+  end
+
+  defp validate_email(changeset, opts) do
+    changeset =
+      changeset
+      |> validate_required([:email])
+      |> validate_format(:email, ~r/^[^@,;\s]+@[^@,;\s]+$/,
+        message: "must have the @ sign and no spaces"
+      )
+      |> validate_length(:email, max: 160)
+
+    if Keyword.get(opts, :validate_unique, true) do
+      changeset
+      |> unsafe_validate_unique(:email, BeetRoundServer.Repo)
+      |> unique_constraint(:email)
+      |> validate_email_changed()
+    else
+      changeset
+    end
+  end
+
+  defp validate_email_changed(changeset) do
+    if get_field(changeset, :email) && get_change(changeset, :email) == nil do
+      add_error(changeset, :email, "did not change")
+    else
+      changeset
+    end
+  end
+
+  @doc """
+  A admin changeset for changing the password.
+
+  It is important to validate the length of the password, as long passwords may
+  be very expensive to hash for certain algorithms.
+
+  ## Options
+
+    * `:hash_password` - Hashes the password so it can be stored securely
+      in the database and ensures the password field is cleared to prevent
+      leaks in the logs. If password hashing is not needed and clearing the
+      password field is not desired (like when using this changeset for
+      validations on a LiveView form), this option can be set to `false`.
+      Defaults to `true`.
+  """
+  def password_changeset(admin, attrs, opts \\ []) do
+    admin
+    |> cast(attrs, [:password])
+    |> validate_confirmation(:password, message: "does not match password")
+    |> validate_password(opts)
+  end
+
+  defp validate_password(changeset, opts) do
+    changeset
+    |> validate_required([:password])
+    |> validate_length(:password, min: 12, max: 72)
+    # Examples of additional password validation:
+    # |> validate_format(:password, ~r/[a-z]/, message: "at least one lower case character")
+    # |> validate_format(:password, ~r/[A-Z]/, message: "at least one upper case character")
+    # |> validate_format(:password, ~r/[!?@#$%^&*_0-9]/, message: "at least one digit or punctuation character")
+    |> maybe_hash_password(opts)
+  end
+
+  defp maybe_hash_password(changeset, opts) do
+    hash_password? = Keyword.get(opts, :hash_password, true)
+    password = get_change(changeset, :password)
+
+    if hash_password? && password && changeset.valid? do
+      changeset
+      # If using Bcrypt, then further validate it is at most 72 bytes long
+      |> validate_length(:password, max: 72, count: :bytes)
+      # Hashing could be done with `Ecto.Changeset.prepare_changes/2`, but that
+      # would keep the database transaction open longer and hurt performance.
+      |> put_change(:hashed_password, Bcrypt.hash_pwd_salt(password))
+      |> delete_change(:password)
+    else
+      changeset
+    end
+  end
+
+  @doc """
+  Confirms the account by setting `confirmed_at`.
+  """
+  def confirm_changeset(admin) do
+    now = DateTime.utc_now(:second)
+    change(admin, confirmed_at: now)
+  end
+
+  @doc """
+  Verifies the password.
+
+  If there is no admin or the admin doesn't have a password, we call
+  `Bcrypt.no_user_verify/0` to avoid timing attacks.
+  """
+  def valid_password?(%BeetRoundServer.Admins.Admin{hashed_password: hashed_password}, password)
+      when is_binary(hashed_password) and byte_size(password) > 0 do
+    Bcrypt.verify_pass(password, hashed_password)
+  end
+
+  def valid_password?(_, _) do
+    Bcrypt.no_user_verify()
+    false
+  end
+end

lib/beet_round_server/admins/admin_notifier.ex

@@ -0,0 +1,84 @@
+defmodule BeetRoundServer.Admins.AdminNotifier do
+  import Swoosh.Email
+
+  alias BeetRoundServer.Mailer
+  alias BeetRoundServer.Admins.Admin
+
+  # Delivers the email using the application mailer.
+  defp deliver(recipient, subject, body) do
+    email =
+      new()
+      |> to(recipient)
+      |> from({"BeetRoundServer", "contact@example.com"})
+      |> subject(subject)
+      |> text_body(body)
+
+    with {:ok, _metadata} <- Mailer.deliver(email) do
+      {:ok, email}
+    end
+  end
+
+  @doc """
+  Deliver instructions to update a admin email.
+  """
+  def deliver_update_email_instructions(admin, url) do
+    deliver(admin.email, "Update email instructions", """
+
+    ==============================
+
+    Hi #{admin.email},
+
+    You can change your email by visiting the URL below:
+
+    #{url}
+
+    If you didn't request this change, please ignore this.
+
+    ==============================
+    """)
+  end
+
+  @doc """
+  Deliver instructions to log in with a magic link.
+  """
+  def deliver_login_instructions(admin, url) do
+    case admin do
+      %Admin{confirmed_at: nil} -> deliver_confirmation_instructions(admin, url)
+      _ -> deliver_magic_link_instructions(admin, url)
+    end
+  end
+
+  defp deliver_magic_link_instructions(admin, url) do
+    deliver(admin.email, "Log in instructions", """
+
+    ==============================
+
+    Hi #{admin.email},
+
+    You can log into your account by visiting the URL below:
+
+    #{url}
+
+    If you didn't request this email, please ignore this.
+
+    ==============================
+    """)
+  end
+
+  defp deliver_confirmation_instructions(admin, url) do
+    deliver(admin.email, "Confirmation instructions", """
+
+    ==============================
+
+    Hi #{admin.email},
+
+    You can confirm your account by visiting the URL below:
+
+    #{url}
+
+    If you didn't create an account with us, please ignore this.
+
+    ==============================
+    """)
+  end
+end

lib/beet_round_server/admins/admin_token.ex

@@ -0,0 +1,195 @@
+defmodule BeetRoundServer.Admins.AdminToken do
+  use Ecto.Schema
+  import Ecto.Query
+  alias BeetRoundServer.Admins.AdminToken
+
+  @hash_algorithm :sha256
+  @rand_size 32
+
+  # It is very important to keep the magic link token expiry short,
+  # since someone with access to the email may take over the account.
+  @magic_link_validity_in_minutes 15
+  @change_email_validity_in_days 7
+  @session_validity_in_days 14
+  @api_validity_in_days 30
+
+  @primary_key {:id, :binary_id, autogenerate: true}
+  @foreign_key_type :binary_id
+  schema "admins_tokens" do
+    field :token, :binary
+    field :context, :string
+    field :sent_to, :string
+    field :authenticated_at, :utc_datetime
+    belongs_to :admin, BeetRoundServer.Admins.Admin
+
+    timestamps(type: :utc_datetime, updated_at: false)
+  end
+
+  @doc """
+  Generates a token that will be stored in a signed place,
+  such as session or cookie. As they are signed, those
+  tokens do not need to be hashed.
+
+  The reason why we store session tokens in the database, even
+  though Phoenix already provides a session cookie, is because
+  Phoenix's default session cookies are not persisted, they are
+  simply signed and potentially encrypted. This means they are
+  valid indefinitely, unless you change the signing/encryption
+  salt.
+
+  Therefore, storing them allows individual admin
+  sessions to be expired. The token system can also be extended
+  to store additional data, such as the device used for logging in.
+  You could then use this information to display all valid sessions
+  and devices in the UI and allow users to explicitly expire any
+  session they deem invalid.
+  """
+  def build_session_token(admin) do
+    token = :crypto.strong_rand_bytes(@rand_size)
+    dt = admin.authenticated_at || DateTime.utc_now(:second)
+
+    {token,
+     %AdminToken{token: token, context: "session", admin_id: admin.id, authenticated_at: dt}}
+  end
+
+  @doc """
+  Checks if the token is valid and returns its underlying lookup query.
+
+  The query returns the admin found by the token, if any, along with the token's creation time.
+
+  The token is valid if it matches the value in the database and it has
+  not expired (after @session_validity_in_days).
+  """
+  def verify_session_token_query(token) do
+    query =
+      from token in by_token_and_context_query(token, "session"),
+        join: admin in assoc(token, :admin),
+        where: token.inserted_at > ago(@session_validity_in_days, "day"),
+        select: {%{admin | authenticated_at: token.authenticated_at}, token.inserted_at}
+
+    {:ok, query}
+  end
+
+  @doc """
+  Builds a token and its hash to be delivered to the admin's email.
+
+  The non-hashed token is sent to the admin email while the
+  hashed part is stored in the database. The original token cannot be reconstructed,
+  which means anyone with read-only access to the database cannot directly use
+  the token in the application to gain access. Furthermore, if the admin changes
+  their email in the system, the tokens sent to the previous email are no longer
+  valid.
+
+  Users can easily adapt the existing code to provide other types of delivery methods,
+  for example, by phone numbers.
+  """
+  def build_email_token(admin, context) do
+    build_hashed_token(admin, context, admin.email)
+  end
+
+  defp build_hashed_token(admin, context, sent_to) do
+    token = :crypto.strong_rand_bytes(@rand_size)
+    hashed_token = :crypto.hash(@hash_algorithm, token)
+
+    {Base.url_encode64(token, padding: false),
+     %AdminToken{
+       token: hashed_token,
+       context: context,
+       sent_to: sent_to,
+       admin_id: admin.id
+     }}
+  end
+
+  @doc """
+  Checks if the token is valid and returns its underlying lookup query.
+
+  If found, the query returns a tuple of the form `{admin, token}`.
+
+  The given token is valid if it matches its hashed counterpart in the
+  database. This function also checks if the token is being used within
+  15 minutes. The context of a magic link token is always "login".
+  """
+  def verify_magic_link_token_query(token) do
+    case Base.url_decode64(token, padding: false) do
+      {:ok, decoded_token} ->
+        hashed_token = :crypto.hash(@hash_algorithm, decoded_token)
+
+        query =
+          from token in by_token_and_context_query(hashed_token, "login"),
+            join: admin in assoc(token, :admin),
+            where: token.inserted_at > ago(^@magic_link_validity_in_minutes, "minute"),
+            where: token.sent_to == admin.email,
+            select: {admin, token}
+
+        {:ok, query}
+
+      :error ->
+        :error
+    end
+  end
+
+  @doc """
+  Checks if the token is valid and returns its underlying lookup query.
+
+  The query returns the admin_token found by the token, if any.
+
+  This is used to validate requests to change the admin
+  email.
+  The given token is valid if it matches its hashed counterpart in the
+  database and if it has not expired (after @change_email_validity_in_days).
+  The context must always start with "change:".
+  """
+  def verify_change_email_token_query(token, "change:" <> _ = context) do
+    case Base.url_decode64(token, padding: false) do
+      {:ok, decoded_token} ->
+        hashed_token = :crypto.hash(@hash_algorithm, decoded_token)
+
+        query =
+          from token in by_token_and_context_query(hashed_token, context),
+            where: token.inserted_at > ago(@change_email_validity_in_days, "day")
+
+        {:ok, query}
+
+      :error ->
+        :error
+    end
+  end
+
+  @doc """
+  Checks if the token is valid and returns its underlying lookup query.
+
+  The query returns the admin found by the token, if any.
+
+  The given token is valid if it matches its hashed counterpart in the
+  database and the user email has not changed. This function also checks
+  if the token is being used within a certain period, depending on the
+  context. The default contexts supported by this function are either
+  "confirm", for account confirmation emails, and "reset_password",
+  for resetting the password. For verifying requests to change the email,
+  see `verify_change_email_token_query/2`.
+  """
+  def verify_email_token_query(token, context) do
+    case Base.url_decode64(token, padding: false) do
+      {:ok, decoded_token} ->
+        hashed_token = :crypto.hash(@hash_algorithm, decoded_token)
+        days = days_for_context(context)
+
+        query =
+          from token in by_token_and_context_query(hashed_token, context),
+            join: admin in assoc(token, :admin),
+            where: token.inserted_at > ago(^days, "day") and token.sent_to == admin.email,
+            select: admin
+
+        {:ok, query}
+
+      :error ->
+        :error
+    end
+  end
+
+  defp days_for_context("api-token"), do: @api_validity_in_days
+
+  defp by_token_and_context_query(token, context) do
+    from AdminToken, where: [token: ^token, context: ^context]
+  end
+end

lib/beet_round_server/admins/scope.ex

@@ -0,0 +1,33 @@
+defmodule BeetRoundServer.Admins.Scope do
+  @moduledoc """
+  Defines the scope of the caller to be used throughout the app.
+
+  The `BeetRoundServer.Admins.Scope` 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 BeetRoundServer.Admins.Admin
+
+  defstruct admin: nil
+
+  @doc """
+  Creates a scope for the given admin.
+
+  Returns nil if no admin is given.
+  """
+  def for_admin(%Admin{} = admin) do
+    %__MODULE__{admin: admin}
+  end
+
+  def for_admin(nil), do: nil
+end