Exchange Chinese SSO tokens

lib/tesla_api/auth.ex

@@ -1,6 +1,8 @@
 defmodule TeslaApi.Auth do
   use Tesla
 
+  alias TeslaApi.Error
+
   @web_client_id "ownerapi"
   @redirect_uri "https://auth.tesla.com/void/callback"
 
@@ -26,6 +28,54 @@ defmodule TeslaApi.Auth do
   defdelegate login(email, password), to: __MODULE__.Login
   defdelegate refresh(auth), to: __MODULE__.Refresh
 
+  def issuer_url(%__MODULE__{token: access_token}) do
+    case derive_issuer_url_from_oat(access_token) do
+      {:ok, issuer_url} ->
+        issuer_url
+
+      :error ->
+        case decode_jwt_payload(access_token) do
+          {:ok, %{"iss" => iss}} -> URI.parse(iss)
+          _ -> "https://auth.tesla.com/oauth2/v3"
+        end
+    end
+  end
+
+  def region(%__MODULE__{} = auth) do
+    tld =
+      auth
+      |> issuer_url()
+      |> URI.parse()
+      |> Map.fetch!(:host)
+      |> String.split(".")
+      |> List.last()
+
+    case tld do
+      "cn" -> :chinese
+      "com" -> :global
+      _other -> :other
+    end
+  end
+
+  defp derive_issuer_url_from_oat("qts-" <> _), do: {:ok, "https://auth.tesla.com/oauth2/v3"}
+  defp derive_issuer_url_from_oat("eu-" <> _), do: {:ok, "https://auth.tesla.com/oauth2/v3"}
+  defp derive_issuer_url_from_oat("cn-" <> _), do: {:ok, "https://auth.tesla.cn/oauth2/v3"}
+  defp derive_issuer_url_from_oat(_), do: :error
+
+  defp decode_jwt_payload(jwt) do
+    with [_algo, payload, _signature] <- String.split(jwt, "."),
+         {:ok, payload} <- Base.decode64(payload, padding: false),
+         {:ok, payload} <- Jason.decode(payload) do
+      {:ok, payload}
+    else
+      l when is_list(l) ->
+        Error.into({:error, :invalid_jwt}, :invalid_access_token)
+
+      error ->
+        Error.into(error, :invalid_access_token)
+    end
+  end
+
   defp log_level(%Tesla.Env{} = env) when env.status >= 400, do: :error
   defp log_level(%Tesla.Env{}), do: :info
 end

lib/tesla_api/auth/login.ex

@@ -2,7 +2,7 @@ defmodule TeslaApi.Auth.Login do
   import TeslaApi.Auth, only: [get: 2, post: 2, post: 3]
 
   alias TeslaApi.Error
-  alias TeslaApi.Auth.{MFA, Util}
+  alias TeslaApi.Auth.{MFA, OwnerApi, Util}
 
   require Logger
 
@@ -57,7 +57,8 @@ defmodule TeslaApi.Auth.Login do
     with {:ok, %Tesla.Env{} = env} <- submit_form(form, ctx),
          {:ok, {redirect_uri, code}} <- Util.parse_location_header(env, ctx.state),
          {:ok, auth} <-
-           get_web_token(code, ctx.code_verifier, redirect_uri, ctx.state, base: ctx.base_url) do
+           get_web_token(code, ctx.code_verifier, redirect_uri, ctx.state, base: ctx.base_url),
+         {:ok, auth} <- maybe_exchange_sso_tokens(auth) do
       {:ok, auth}
     end
   rescue
@@ -193,7 +194,8 @@ defmodule TeslaApi.Auth.Login do
                          MFA.verify_passcode(device_id, mfa_passcode, transaction_id, headers),
                        {:ok, {redirect_uri, code}} <- Util.parse_location_header(env, ctx.state),
                        {:ok, auth} <-
-                         get_web_token(code, ctx.code_verifier, redirect_uri, ctx.state) do
+                         get_web_token(code, ctx.code_verifier, redirect_uri, ctx.state),
+                       {:ok, auth} <- maybe_exchange_sso_tokens(auth) do
                     {:ok, auth}
                   end
                 rescue
@@ -247,4 +249,14 @@ defmodule TeslaApi.Auth.Login do
         Error.into(error, :web_token_error)
     end
   end
+
+  defp maybe_exchange_sso_tokens(%TeslaApi.Auth{} = auth) do
+    case TeslaApi.Auth.region(auth) do
+      :chinese ->
+        OwnerApi.exchange_sso_token(auth)
+
+      _other ->
+        {:ok, auth}
+    end
+  end
 end

lib/tesla_api/auth/owner_api.ex

@@ -0,0 +1,34 @@
+defmodule TeslaApi.Auth.OwnerApi do
+  import TeslaApi.Auth, only: [post: 3]
+
+  alias TeslaApi.{Auth, Error}
+
+  @client_id "81527cff06843c8634fdc09e8ac0abefb46ac849f38fe1e431c2ef2106796384"
+  @client_secret "c7257eb71a564034f9419ee651c7d0e5f7aa6bfbd18bafb5c5c033b093bb2fa3"
+
+  def exchange_sso_token(%Auth{} = sso_auth) do
+    data = %{
+      grant_type: "urn:ietf:params:oauth:grant-type:jwt-bearer",
+      client_id: @client_id,
+      client_secret: @client_secret
+    }
+
+    headers = [{"Authorization", "Bearer #{sso_auth.token}"}]
+
+    case post("https://owner-api.teslamotors.com/oauth/token", data, headers: headers) do
+      {:ok, %Tesla.Env{status: 200, body: body}} ->
+        auth = %Auth{
+          token: body["access_token"],
+          type: body["token_type"],
+          expires_in: body["expires_in"],
+          refresh_token: sso_auth.refresh_token,
+          created_at: body["created_at"]
+        }
+
+        {:ok, auth}
+
+      error ->
+        Error.into(error, :api_token_error)
+    end
+  end
+end

lib/tesla_api/auth/refresh.ex

@@ -2,21 +2,12 @@ defmodule TeslaApi.Auth.Refresh do
   import TeslaApi.Auth, only: [post: 2]
 
   alias TeslaApi.{Auth, Error}
+  alias TeslaApi.Auth.OwnerApi
 
   @web_client_id TeslaApi.Auth.web_client_id()
 
   def refresh(%Auth{} = auth) do
-    issuer_url =
-      case derive_issuer_url_from_oat(auth.token) do
-        {:ok, issuer_url} ->
-          issuer_url
-
-        :error ->
-          case decode_jwt_payload(auth.token) do
-            {:ok, %{"iss" => iss}} -> URI.parse(iss)
-            _ -> "https://auth.tesla.com/oauth2/v3"
-          end
-      end
+    issuer_url = Auth.issuer_url(auth)
 
     data = %{
       grant_type: "refresh_token",
@@ -35,29 +26,16 @@ defmodule TeslaApi.Auth.Refresh do
           created_at: body["created_at"]
         }
 
-        {:ok, auth}
+        case Auth.region(auth) do
+          :chinese ->
+            OwnerApi.exchange_sso_token(auth)
+
+          _other ->
+            {:ok, auth}
+        end
 
       error ->
         Error.into(error, :token_refresh)
     end
   end
-
-  defp derive_issuer_url_from_oat("qts-" <> _), do: {:ok, "https://auth.tesla.com/oauth2/v3"}
-  defp derive_issuer_url_from_oat("eu-" <> _), do: {:ok, "https://auth.tesla.com/oauth2/v3"}
-  defp derive_issuer_url_from_oat("cn-" <> _), do: {:ok, "https://auth.tesla.cn/oauth2/v3"}
-  defp derive_issuer_url_from_oat(_), do: :error
-
-  defp decode_jwt_payload(jwt) do
-    with [_algo, payload, _signature] <- String.split(jwt, "."),
-         {:ok, payload} <- Base.decode64(payload, padding: false),
-         {:ok, payload} <- Jason.decode(payload) do
-      {:ok, payload}
-    else
-      l when is_list(l) ->
-        Error.into({:error, :invalid_jwt}, :invalid_access_token)
-
-      error ->
-        Error.into(error, :invalid_access_token)
-    end
-  end
 end