Add minimal SSH key management

lib/recycledcloud/accounts.ex

@@ -5,7 +5,7 @@ defmodule RecycledCloud.Accounts do
 
   import Ecto.Query, warn: false
   alias RecycledCloud.Repo
-  alias RecycledCloud.Accounts.{User, UserToken, UserNotifier}
+  alias RecycledCloud.Accounts.{User, Key, UserToken, UserNotifier}
   alias RecycledCloud.LDAP
 
   ## Database getters
@@ -356,4 +356,27 @@ defmodule RecycledCloud.Accounts do
       {:error, :user, changeset, _} -> {:error, changeset}
     end
   end
+
+  ## Keys
+
+  def get_key!(id), do: Repo.get!(Key, id)
+
+  def get_keys_for(%User{} = user) do
+    Repo.preload(user, :keys).keys
+  end
+
+  def change_user_key(user, attrs \\ %{}) do
+    Key.changeset(user, attrs)
+  end
+
+  def add_key(%User{} = user, value, comment \\ nil) do
+    %Key{}
+    |> Key.changeset(%{value: value, comment: comment})
+    |> Ecto.Changeset.put_assoc(:user, user)
+    |> Repo.insert()
+  end
+
+  def remove_key!(%Key{} = key) do
+    Repo.delete!(key)
+  end
 end

lib/recycledcloud/accounts/key.ex

@@ -0,0 +1,48 @@
+defmodule RecycledCloud.Accounts.Key do
+  use Ecto.Schema
+  import Ecto.Changeset
+
+  schema "keys" do
+    field :comment, :string
+    field :value, :string
+    field :fingerprint, :string
+    belongs_to :user, RecycledCloud.Accounts.User
+
+    timestamps()
+  end
+
+  def process_ssh_key(changeset, value_field, fingerprint_field, comment_field) do
+    raw_value = get_field(changeset, value_field)
+    comment = get_field(changeset, comment_field)
+
+    with {:is_valid, true} <- {:is_valid, changeset.valid?},
+      [{pk, attrs}] <- :public_key.ssh_decode(raw_value, :public_key) do
+
+      fingerprint = :public_key.ssh_hostkey_fingerprint(pk) |> List.to_string
+      changeset = put_change(changeset, fingerprint_field, fingerprint)
+
+      # Fetch comment from key, if not provided.
+      embedded_comment = attrs
+                         |> Enum.into(%{})
+                         |> Map.get(:comment)
+
+      case {comment, embedded_comment} do
+        {nil, nil} -> changeset
+        {nil, new_comment} ->
+          put_change(changeset, comment_field, List.to_string(new_comment))
+        {_, _} -> changeset
+      end
+    else
+      {:is_valid, false} -> changeset
+      _ -> add_error(changeset, value_field, "key is invalid")
+    end
+  end
+
+  @doc false
+  def changeset(key, attrs) do
+    out = key
+    |> cast(attrs, [:comment, :value])
+    |> validate_required([:value])
+    |> process_ssh_key(:value, :fingerprint, :comment)
+  end
+end

lib/recycledcloud/accounts/user.ex

@@ -15,6 +15,8 @@ defmodule RecycledCloud.Accounts.User do
     field :email, :string, virtual: true
     field :confirmed_at, :naive_datetime
 
+    has_many :keys, Accounts.Key
+
     timestamps()
   end
 

lib/recycledcloud_web/controllers/user_keys_controller.ex

@@ -0,0 +1,53 @@
+defmodule RecycledCloudWeb.UserKeysController do
+  use RecycledCloudWeb, :controller
+
+  alias RecycledCloud.Accounts
+
+  def index(conn, %{"username" => username}) do
+    case Accounts.get_user_by_username(username) do
+      nil ->
+        conn
+        |> put_status(:not_found)
+        |> text("")
+
+      user ->
+        keys = Accounts.get_keys_for(user)
+               |> Enum.map(fn k -> k.value end)
+               |> Enum.join("\n")
+
+        body = "# Keys for #{user.username}\n" <> keys
+        conn |> text(body)
+    end
+  end
+
+  def new(conn, %{"key" => key} = params) do
+    %{"value" => value, "comment" => comment} = key
+    user = conn.assigns.current_user
+
+    case Accounts.add_key(user, value, comment) do
+      {:ok, _} ->
+        conn
+        |> put_flash(:info, "Key added successfully.")
+        |> redirect(to: Routes.user_settings_path(conn, :edit))
+
+      {:error, _} ->
+        conn
+        |> put_flash(:error, "Submitted key is invalid.")
+        |> redirect(to: Routes.user_settings_path(conn, :edit))
+    end
+  end
+
+  def delete(conn, %{"key_id" => id}) do
+    user = conn.assigns.current_user
+    key = Accounts.get_key!(id)
+
+    if key.user_id == user.id do
+      Accounts.remove_key!(key)
+
+      conn
+      |> put_flash(:info, "Key removed.")
+      |> redirect(to: Routes.user_settings_path(conn, :edit))
+    end
+
+  end
+end

lib/recycledcloud_web/controllers/user_settings_controller.ex

@@ -70,5 +70,7 @@ defmodule RecycledCloudWeb.UserSettingsController do
     conn
     |> assign(:email_changeset, Accounts.change_user_email(user))
     |> assign(:password_changeset, Accounts.change_user_password(user))
+    |> assign(:key_changeset, Accounts.change_user_key(%Accounts.Key{}))
+    |> assign(:keys, Accounts.get_keys_for(user))
   end
 end

lib/recycledcloud_web/router.ex

@@ -16,16 +16,21 @@ defmodule RecycledCloudWeb.Router do
     plug :accepts, ["json"]
   end
 
+  pipeline :plain do
+    plug :accepts, ["text"]
+  end
+
   scope "/", RecycledCloudWeb do
     pipe_through :browser
 
     get "/", PageController, :index
   end
 
-  # Other scopes may use custom stacks.
-  # scope "/api", RecycledCloudWeb do
-  #   pipe_through :api
-  # end
+  scope "/", RecycledCloudWeb do
+    pipe_through :plain
+
+    get "/keys/:username", UserKeysController, :index
+  end
 
   ## Authentication routes
 
@@ -48,6 +53,8 @@ defmodule RecycledCloudWeb.Router do
     get "/users/settings", UserSettingsController, :edit
     put "/users/settings", UserSettingsController, :update
     get "/users/settings/confirm_email/:token", UserSettingsController, :confirm_email
+    post "/users/settings/keys/new", UserKeysController, :new
+    get  "/users/settings/keys/:key_id/delete", UserKeysController, :delete
   end
 
   scope "/", RecycledCloudWeb do

lib/recycledcloud_web/templates/user_settings/edit.html.eex

@@ -58,3 +58,46 @@ method.
     <%= submit "Change password" %>
   </div>
 <% end %>
+
+<h3>SSH Keys</h3>
+
+<%= form_for @key_changeset, Routes.user_keys_path(@conn, :new), fn f -> %>
+  <%= if @key_changeset.action do %>
+    <div class="alert alert-danger">
+      <p>Oops, something went wrong! Please check the errors below.</p>
+    </div>
+  <% end %>
+
+  <%= text_input f, :comment, placeholder: "comment" %>
+  <%= error_tag f, :comment %>
+
+  <br />
+
+  <%= textarea f, :value, required: true, placeholder: "value" %>
+  <%= error_tag f, :value %>
+
+  <div>
+    <%= submit "Add key" %>
+  </div>
+<% end %>
+
+<table>
+  <thead>
+    <tr>
+      <th>Comment</th>
+      <th>Imported on</th>
+      <th>Fingerprint</th>
+      <th>Actions</th>
+    </tr>
+  </thead>
+  <tbody>
+    <%= for key <- @keys do %>
+      <tr>
+        <td><%= key.comment %></td>
+        <td><%= key.inserted_at %></td>
+        <td><%= key.fingerprint %></td>
+        <td><%= link "Delete", to: Routes.user_keys_path(@conn, :delete, key.id) %></td>
+      </tr>
+    <% end %>
+  </tbody>
+</table>

priv/repo/migrations/20201222142443_create_keys.exs

@@ -0,0 +1,15 @@
+defmodule RecycledCloud.Repo.Migrations.CreateKeys do
+  use Ecto.Migration
+
+  def change do
+    create table(:keys) do
+      add :comment, :string
+      add :value, :text
+      add :user_id, references(:users, on_delete: :nothing)
+
+      timestamps()
+    end
+
+    create index(:keys, [:user_id])
+  end
+end

priv/repo/migrations/20201223114606_add_key_fingerprint.exs

@@ -0,0 +1,10 @@
+defmodule RecycledCloud.Repo.Migrations.AddKeyFingerprint do
+  use Ecto.Migration
+
+  def change do
+    alter table(:keys) do
+      add :fingerprint, :string
+    end
+
+  end
+end