WIP: Authenticate

backends/auth.go

@@ -0,0 +1,60 @@
+/*
+Copyright © 2023 Philipp Wolfer <phw@uploadedlobster.com>
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
+*/
+
+package backends
+
+import (
+	"net/url"
+	"strings"
+
+	"github.com/spf13/viper"
+	"go.uploadedlobster.com/scotty/models"
+	"go.uploadedlobster.com/scotty/storage"
+)
+
+func BuildRedirectURL(config *viper.Viper, backend string) (*url.URL, error) {
+	callbackHost, _ := strings.CutSuffix(config.GetString("oauth-host"), "/")
+	if callbackHost == "" {
+		callbackHost = "127.0.0.1:2369"
+	}
+	callbackPath := "/callback/" + backend
+	return url.Parse("http://" + callbackHost + callbackPath)
+}
+
+func Authenticate(backend models.Backend, db storage.Database, config *viper.Viper) error {
+	authenticator, auth := backend.(models.OAuth2Authenticator)
+	if auth {
+		// FIXME
+		backendName := "spotify"
+		redirectURL, err := BuildRedirectURL(config, backendName)
+		if err != nil {
+			return err
+		}
+		// FIXME
+		token, err := db.GetOAuth2Token("spotify")
+		if err != nil {
+			return err
+		}
+		authenticator.OAuth2Setup(redirectURL.String(), token)
+	}
+	return nil
+}

backends/auth_test.go

@@ -0,0 +1,49 @@
+/*
+Copyright © 2023 Philipp Wolfer <phw@uploadedlobster.com>
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
+*/
+
+package backends_test
+
+import (
+	"testing"
+
+	"github.com/spf13/viper"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"go.uploadedlobster.com/scotty/backends"
+)
+
+func TestBuildRedirectURL(t *testing.T) {
+	config := viper.New()
+	config.Set("oauth-host", "localhost:1234/")
+	url, err := backends.BuildRedirectURL(config, "foo")
+	require.NoError(t, err)
+	assert.Equal(t, "localhost:1234", url.Host)
+	assert.Equal(t, "/callback/foo", url.Path)
+}
+
+func TestBuildRedirectURLDefaultHost(t *testing.T) {
+	config := viper.New()
+	url, err := backends.BuildRedirectURL(config, "foo")
+	require.NoError(t, err)
+	assert.Equal(t, "127.0.0.1:2369", url.Host)
+	assert.Equal(t, "/callback/foo", url.Path)
+}

backends/backends.go

@@ -60,6 +60,7 @@ func ResolveBackend[T interface{}](config *viper.Viper) (T, error) {
 		err = errors.New(
 			fmt.Sprintf("Backend %s does not implement %s", backendName, interfaceName))
 	}
+
 	return result, err
 }
 

cmd/auth.go

@@ -25,11 +25,11 @@ import (
 	"context"
 	"fmt"
 	"net/http"
-	"strings"
 
 	"github.com/cli/browser"
 	"github.com/spf13/cobra"
 	"github.com/spf13/viper"
+	"go.uploadedlobster.com/scotty/backends"
 	"go.uploadedlobster.com/scotty/storage"
 	"golang.org/x/oauth2"
 	"golang.org/x/oauth2/spotify"
@@ -42,34 +42,30 @@ var authCmd = &cobra.Command{
 	Long:  `For backends requiring authentication this command can be used to authenticate.`,
 	Run: func(cmd *cobra.Command, args []string) {
 		serviceName, serviceConfig := getConfigFromFlag(cmd, "service")
-		fmt.Print("HERE\n")
 		backend := serviceConfig.GetString("backend")
 
-		callbackHost, _ := strings.CutSuffix(viper.GetString("oauth-host"), "/")
+		redirectURL, err := backends.BuildRedirectURL(viper.GetViper(), backend)
-		if callbackHost == "" {
+		cobra.CheckErr(err)
-			callbackHost = "127.0.0.1:2369"
-		}
-		callbackPath := "/callback/" + backend
 
 		ctx := context.Background()
 		conf := &oauth2.Config{
 			ClientID:     serviceConfig.GetString("client-id"),
 			ClientSecret: serviceConfig.GetString("client-secret"),
 			Scopes:       []string{"user-read-recently-played"},
-			RedirectURL:  "http://" + callbackHost + callbackPath,
+			RedirectURL:  redirectURL.String(),
 			Endpoint:     spotify.Endpoint,
 		}
 
 		responseChan := make(chan string)
 
 		// Start an HTTP server to listen for the response
-		http.HandleFunc(callbackPath, func(w http.ResponseWriter, r *http.Request) {
+		http.HandleFunc(redirectURL.Path, func(w http.ResponseWriter, r *http.Request) {
 			code := r.URL.Query().Get("code")
 			fmt.Fprint(w, "Token received, you can close this window now.")
 			responseChan <- code
 		})
 
-		go http.ListenAndServe(callbackHost, nil)
+		go http.ListenAndServe(redirectURL.Host, nil)
 
 		// use PKCE to protect against CSRF attacks
 		// https://www.ietf.org/archive/id/draft-ietf-oauth-security-topics-22.html#name-countermeasures-6
@@ -80,7 +76,7 @@ var authCmd = &cobra.Command{
 		url := conf.AuthCodeURL("state", oauth2.AccessTypeOffline, oauth2.S256ChallengeOption(verifier))
 		fmt.Printf("Visit the URL for the auth dialog: %v\n", url)
 
-		err := browser.OpenURL(url)
+		err = browser.OpenURL(url)
 		cobra.CheckErr(err)
 
 		code := <-responseChan

models/interfaces.go

@@ -35,15 +35,6 @@ type Backend interface {
 	FromConfig(config *viper.Viper) Backend
 }
 
-type OAuth2Backend interface {
-	Backend
-	// Returns OAuth2 config suitable for this backend
-	OAuth2Config(redirectUrl string) oauth2.Config
-
-	// Setup the OAuth2 client
-	OAuth2Setup(redirectUrl string, token *oauth2.Token) error
-}
-
 type ImportBackend interface {
 	Backend
 
@@ -91,3 +82,12 @@ type LovesImport interface {
 	// Imports the given list of loves.
 	ImportLoves(export LovesResult, importResult ImportResult, progress chan Progress) (ImportResult, error)
 }
+
+// Must be implemented by backends requiring OAuth2 authentication
+type OAuth2Authenticator interface {
+	// Returns OAuth2 config suitable for this backend
+	OAuth2Config(redirectUrl string) oauth2.Config
+
+	// Setup the OAuth2 client
+	OAuth2Setup(redirectUrl string, token *oauth2.Token) error
+}