Merge pull request #178 from overmindtech/device-authz

Use Device Authorization flow

Author: DavidS-ovm

cmd/root.go

@@ -7,13 +7,11 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
-	"net/http"
 	"net/url"
 	"os"
 	"path"
 	"path/filepath"
 	"strings"
-	"time"
 
 	"connectrpc.com/connect"
 	"github.com/google/uuid"
@@ -26,9 +24,6 @@ import (
 	"golang.org/x/oauth2"
 )
 
-const Auth0ClientId = "j3LylZtIosVPZtouKI8WuVHmE6Lluva1"
-const Auth0Domain = "om-prod.eu.auth0.com"
-
 var logLevel string
 
 //go:generate sh -c "echo -n $(git describe --tags --long) > commit.txt"
@@ -147,6 +142,7 @@ func readLocalToken(homeDir string, expectedScopes []string) (string, []string,
 		}
 	}
 
+	log.Debugf("Using local token from %v", path)
 	return token.AccessToken, currentScopes, nil
 }
 
@@ -204,92 +200,28 @@ func ensureToken(ctx context.Context, requiredScopes []string) (context.Context,
 		// keep replacing it
 		requestScopes := append(requiredScopes, localScopes...)
 
-		// Authenticate using the oauth resource owner password flow
+		// Authenticate using the oauth device authorization flow
 		config := oauth2.Config{
-			ClientID: Auth0ClientId,
-			Scopes:   requestScopes,
+			ClientID: viper.GetString("cli-auth0-client-id"),
 			Endpoint: oauth2.Endpoint{
-				AuthURL:  fmt.Sprintf("https://%v/authorize", Auth0Domain),
-				TokenURL: fmt.Sprintf("https://%v/oauth/token", Auth0Domain),
+				AuthURL:       fmt.Sprintf("https://%v/authorize", viper.GetString("cli-auth0-domain")),
+				TokenURL:      fmt.Sprintf("https://%v/oauth/token", viper.GetString("cli-auth0-domain")),
+				DeviceAuthURL: fmt.Sprintf("https://%v/oauth/device/code", viper.GetString("cli-auth0-domain")),
 			},
-			RedirectURL: "http://127.0.0.1:7837/oauth/callback",
+			Scopes: requestScopes,
 		}
 
-		tokenChan := make(chan *oauth2.Token, 1)
-		// create a random token for this exchange
-		oAuthStateString := uuid.New().String()
-
-		// Start the web server to listen for the callback
-		handler := func(w http.ResponseWriter, r *http.Request) {
-			ctx := r.Context()
-
-			queryParts, err := url.ParseQuery(r.URL.RawQuery)
-			if err != nil {
-				log.WithContext(ctx).WithError(err).WithFields(log.Fields{
-					"url": r.URL,
-				}).Error("Failed to parse url")
-			}
-
-			// Use the authorization code that is pushed to the redirect
-			// URL.
-			code := queryParts["code"][0]
-			log.WithContext(ctx).Debugf("Got code: %v", code)
-
-			state := queryParts["state"][0]
-			log.WithContext(ctx).Debugf("Got state: %v", state)
-
-			if state != oAuthStateString {
-				log.WithContext(ctx).Errorf("Invalid state, expected %v, got %v", oAuthStateString, state)
-				return
-			}
-
-			// Exchange will do the handshake to retrieve the initial access token.
-			log.WithContext(ctx).Debug("Exchanging code for token")
-			tok, err := config.Exchange(ctx, code)
-			if err != nil {
-				log.WithContext(ctx).Error(err)
-				return
-			}
-			log.WithContext(ctx).Debug("Got token")
-
-			tokenChan <- tok
-
-			// show success page
-			msg := "<p><strong>Success!</strong></p>"
-			msg = msg + "<p>You are authenticated and can now return to the CLI.</p>"
-			fmt.Fprint(w, msg)
+		deviceCode, err := config.DeviceAuth(ctx, oauth2.SetAuthURLParam("audience", "https://api.overmind.tech"))
+		if err != nil {
+			return ctx, fmt.Errorf("error getting device code: %w", err)
 		}
 
-		audienceOption := oauth2.SetAuthURLParam("audience", "https://api.overmind.tech")
-
-		u := config.AuthCodeURL(oAuthStateString, oauth2.AccessTypeOnline, audienceOption)
-		log.WithContext(ctx).Infof("Follow this link to authenticate: %v", Underline.TextStyle(u))
+		fmt.Printf("Go to %v and verify this code: %v\n", deviceCode.VerificationURIComplete, deviceCode.UserCode)
 
-		// Start the webserver
-		log.WithContext(ctx).Trace("Starting webserver to listen for callback, press Ctrl+C to cancel")
-		srv := &http.Server{Addr: ":7837", ReadHeaderTimeout: 30 * time.Second}
-		http.HandleFunc("/oauth/callback", handler)
-
-		go func() {
-			if err := srv.ListenAndServe(); err != http.ErrServerClosed {
-				// unexpected error. port in use?
-				log.WithContext(ctx).Errorf("HTTP Server error: %v", err)
-			}
-		}()
-
-		// Wait for the token or cancel
-		var token *oauth2.Token
-		select {
-		case token = <-tokenChan:
-			// Keep working
-		case <-ctx.Done():
-			return ctx, ctx.Err()
-		}
-
-		// Stop the server
-		err = srv.Shutdown(ctx)
+		token, err := config.DeviceAccessToken(ctx, deviceCode)
 		if err != nil {
-			log.WithContext(ctx).WithError(err).Warn("failed to shutdown auth callback server, but continuing anyway")
+			fmt.Printf(": %v\n", err)
+			return ctx, fmt.Errorf("Error exchanging Device Code for for access token: %w", err)
 		}
 
 		// Check that we actually got the claims we asked for. If you don't have
@@ -438,15 +370,17 @@ func init() {
 		log.WithError(err).Fatal("could not bind api key to env")
 	}
 
-	// tracing
+	// internal configs
+	rootCmd.PersistentFlags().String("cli-auth0-client-id", "QMfjMww3x4QTpeXiuRtMV3JIQkx6mZa4", "OAuth Client ID to use when connecting with auth0")
+	rootCmd.PersistentFlags().String("cli-auth0-domain", "om-prod.eu.auth0.com", "Auth0 domain to connect to")
 	rootCmd.PersistentFlags().String("honeycomb-api-key", "", "If specified, configures opentelemetry libraries to submit traces to honeycomb. This requires --otel to be set.")
-	// Mark this as hidden. This means that it will still be parsed of supplied,
+
+	// Mark these as hidden. This means that it will still be parsed of supplied,
 	// and we will still look for it in the environment, but it won't be shown
 	// in the help
-	err = rootCmd.PersistentFlags().MarkHidden("honeycomb-api-key")
-	if err != nil {
-		log.WithError(err).Fatal("could not mark `honeycomb-api-key` flag as hidden")
-	}
+	must(rootCmd.PersistentFlags().MarkHidden("cli-auth0-client-id"))
+	must(rootCmd.PersistentFlags().MarkHidden("cli-auth0-domain"))
+	must(rootCmd.PersistentFlags().MarkHidden("honeycomb-api-key"))
 
 	// Create groups
 	rootCmd.AddGroup(&cobra.Group{
@@ -502,3 +436,11 @@ func initConfig() {
 	viper.SetEnvKeyReplacer(replacer)
 	viper.AutomaticEnv() // read in environment variables that match
 }
+
+// must panics if the passed in error is not nil
+// use this for init-time error checking of viper/cobra stuff that sometimes errors if the flag does not exist
+func must(err error) {
+	if err != nil {
+		panic(fmt.Errorf("error initialising: %w", err))
+	}
+}