Fix delete behaviour

README.md

@@ -1,12 +1,8 @@
 # gonotes
 
-A toyish project for a shared notebook of sorts implemented in go.  It's mostly
-a learning opportunity for using go, and partially an intent to end up with a
-shared notebook!
-
-It's not shared in the sense of simultaneous editing, don't do that!
-
-## TODO
-
-* handle static urls in the django url mapping style
-* Style up the templates better
+A shared notebook of sorts implemented in go. Shared here means that the
+content is visible to more than one user.  It does not currently support
+simultaneous editing and there are no plans to do that.  Furthe, it
+*currently* does not support the concept of a lock or checkout when a note
+is edited.  It's the responsibility of the editing parties to prevent races
+and conflicts.

cmd/server/main.go

@@ -12,18 +12,26 @@ import (
 	"forgejo.gwairfelin.com/max/gonotes/internal/middleware"
 	"forgejo.gwairfelin.com/max/gonotes/internal/notes"
 	"forgejo.gwairfelin.com/max/gonotes/internal/notes/views"
+	"golang.org/x/oauth2"
 )
 
 func main() {
 	var confFile string
 
-	sessions := middleware.NewSessionStore()
-
 	flag.StringVar(&confFile, "c", "/etc/gonotes/conf.toml", "Specify path to config file.")
 	flag.Parse()
 
 	conf.LoadConfig(confFile)
 
+	oauth := &oauth2.Config{
+		ClientID:     conf.Conf.OIDC.ClientID,
+		ClientSecret: conf.Conf.OIDC.ClientSecret,
+		Endpoint:     oauth2.Endpoint{AuthURL: conf.Conf.OIDC.AuthURL, TokenURL: conf.Conf.OIDC.TokenURL},
+		RedirectURL:  conf.Conf.OIDC.RedirectURL,
+	}
+
+	sessions := middleware.NewSessionStore(oauth, "/auth")
+
 	err := notes.Init()
 	if err != nil {
 		log.Fatal(err)
@@ -33,6 +41,7 @@ func main() {
 
 	router := http.NewServeMux()
 	notesRouter := views.GetRoutes("/notes")
+	sessionRouter := sessions.Routes.GetRouter()
 
 	cacheExpiration, err := time.ParseDuration("24h")
 	if err != nil {
@@ -41,31 +50,21 @@ func main() {
 
 	etag := middleware.NewETag("static", cacheExpiration)
 
-	if !conf.Conf.Production {
-		router.HandleFunc("/login/", func(w http.ResponseWriter, r *http.Request) {
-			user := r.FormValue("user")
-			if len(user) == 0 {
-				user = "anon"
-			}
-			sessions.Login(user, w)
-
-			http.Redirect(w, r, "/notes/", http.StatusFound)
-		})
-	}
-	router.Handle("/logout/", sessions.AsMiddleware(
-		http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-			user := r.FormValue("user")
-			if len(user) == 0 {
-				user = "anon"
-			}
-
-			sessions.Logout(w, r)
-
-			http.Redirect(w, r, "/notes/", http.StatusFound)
-		})))
-
 	router.Handle("/", middleware.LoggingMiddleware(http.RedirectHandler("/notes/", http.StatusFound)))
-	router.Handle("/notes/", sessions.AsMiddleware(middleware.LoggingMiddleware(http.StripPrefix("/notes", notesRouter))))
+	router.Handle(
+		"/notes/",
+		sessions.AsMiddleware(
+			middleware.LoggingMiddleware(
+				middleware.RejectAnonMiddleware(
+					"/auth/login/",
+					http.StripPrefix(
+						"/notes", notesRouter,
+					),
+				),
+			),
+		),
+	)
+	router.Handle("/auth/", sessions.AsMiddleware(middleware.LoggingMiddleware(http.StripPrefix("/auth", sessionRouter))))
 	router.Handle(
 		"/static/",
 		middleware.LoggingMiddleware(

go.mod

@@ -8,9 +8,7 @@ require (
 	forgejo.gwairfelin.com/max/gispatcho v0.1.2
 	github.com/pelletier/go-toml/v2 v2.2.3
 	github.com/teekennedy/goldmark-markdown v0.5.1
-)
-
-require (
-	github.com/yuin/goldmark-meta v1.1.0 // indirect
-	gopkg.in/yaml.v2 v2.3.0 // indirect
+	github.com/yuin/goldmark-meta v1.1.0
+	golang.org/x/oauth2 v0.34.0
+	gopkg.in/yaml.v2 v2.3.0
 )

go.sum

@@ -18,6 +18,9 @@ github.com/yuin/goldmark-meta v1.1.0 h1:pWw+JLHGZe8Rk0EGsMVssiNb/AaPMHfSRszZeUei
 github.com/yuin/goldmark-meta v1.1.0/go.mod h1:U4spWENafuA7Zyg+Lj5RqK/MF+ovMYtBvXi1lBb2VP0=
 go.abhg.dev/goldmark/toc v0.11.0 h1:IRixVy3/yVPKvFBc37EeBPi8XLTXrtH6BYaonSjkF8o=
 go.abhg.dev/goldmark/toc v0.11.0/go.mod h1:XMFIoI1Sm6dwF9vKzVDOYE/g1o5BmKXghLG8q/wJNww=
+golang.org/x/oauth2 v0.34.0 h1:hqK/t4AKgbqWkdkcAeI8XLmbK+4m4G5YeQRrmiotGlw=
+golang.org/x/oauth2 v0.34.0/go.mod h1:lzm5WQJQwKZ3nwavOZ3IS5Aulzxi68dUSgRHujetwEA=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/yaml.v2 v2.3.0 h1:clyUAQHOM3G0M3f5vQj7LuJrETvjVot3Z5el9nffUtU=
 gopkg.in/yaml.v2 v2.3.0/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=

internal/auth/oauth.go

@@ -0,0 +1,66 @@
+package auth
+
+import (
+	"context"
+	"crypto/rand"
+	"encoding/base64"
+	"encoding/json"
+	"fmt"
+	"net/http"
+
+	"forgejo.gwairfelin.com/max/gonotes/internal/conf"
+	"golang.org/x/oauth2"
+)
+
+func GenerateStateOAUTHCookie(w http.ResponseWriter, prefix string) string {
+
+	b := make([]byte, 16)
+	rand.Read(b)
+	state := base64.URLEncoding.EncodeToString(b)
+	cookie := http.Cookie{
+		Name: "oauthstate", Value: state,
+		MaxAge: 30, Secure: true, HttpOnly: true, Path: prefix,
+	}
+	http.SetCookie(w, &cookie)
+
+	return state
+}
+
+func GetUserFromForgejo(code string, oauth *oauth2.Config) (string, error) {
+	// Use code to get token and get user info from Google.
+
+	token, err := oauth.Exchange(context.Background(), code)
+	if err != nil {
+		return "", fmt.Errorf("code exchange wrong: %s", err.Error())
+	}
+
+	request, err := http.NewRequest("GET", conf.Conf.OIDC.UserinfoURL, nil)
+	if err != nil {
+		return "", fmt.Errorf("failed to init http client for userinfo: %s", err.Error())
+	}
+	request.Header.Set("Authorization", fmt.Sprintf("token %s", token.AccessToken))
+	response, err := http.DefaultClient.Do(request)
+
+	if err != nil {
+		return "", fmt.Errorf("failed getting user info: %s", err.Error())
+	}
+	defer response.Body.Close()
+
+	uInf := make(map[string]any)
+
+	err = json.NewDecoder(response.Body).Decode(&uInf)
+	if err != nil {
+		return "", fmt.Errorf("failed to parse response as json: %s", err.Error())
+	}
+
+	username, ok := uInf["preferred_username"]
+	if !ok {
+		return "", fmt.Errorf("no username in response: %s", err.Error())
+	}
+	userStr, ok := username.(string)
+	if !ok {
+		return "", fmt.Errorf("username not a string: %s", err.Error())
+	}
+
+	return userStr, nil
+}

internal/conf/conf.go

@@ -60,6 +60,15 @@ type Config struct {
 	NotesDir   string
 	LogAccess  bool
 	Production bool
+	OIDC       struct {
+		ClientID     string `toml:"client_id"`
+		ClientSecret string `toml:"client_secret"`
+		AuthURL      string `toml:"auth_url"`
+		TokenURL     string `toml:"token_url"`
+		RedirectURL  string `toml:"redirect_url"`
+		UserinfoURL  string `toml:"userinfo_url"`
+	}
+	AnonCIDRs []string `toml:"anon_networks"`
 }
 
 var (

internal/conf/templates/base.tmpl.html

@@ -62,9 +62,15 @@
                             </ul>
                         </li>
                         {{template "navLinks" .}}
+                        {{if eq .user "anon"}}
                         <li>
-                            <a class="nav-link" href="/logout/">Logout {{.user}}</a>
+                            <a class="nav-link" href="/auth/login/">Login</a>
                         </li>
+                        {{else}}
+                        <li>
+                            <a class="nav-link" href="/auth/logout/">Logout {{.user}}</a>
+                        </li>
+                        {{end}}
                     </ul>
                     {{template "navExtra" .}}
                 </div>

internal/middleware/reject_anon.go

@@ -0,0 +1,99 @@
+// Middleware designed to reject requests from anon users unless from 'safe'
+// IP addresses
+
+package middleware
+
+import (
+	"errors"
+	"fmt"
+	"log"
+	"net"
+	"net/http"
+	"strings"
+
+	"forgejo.gwairfelin.com/max/gonotes/internal/conf"
+)
+
+type netList []net.IPNet
+
+const ipHeader = "x-forwarded-for"
+
+// Check if any IPNet in the netList contains the given IP
+func (n *netList) Contains(ip net.IP) bool {
+	for _, net := range *n {
+		if contains := net.Contains(ip); contains {
+			return true
+		}
+	}
+	return false
+}
+
+// Redirect to redirect url any request where the user is anon and the request
+// does not appear to come from a safe origin
+func RejectAnonMiddleware(redirect string, next http.Handler) http.Handler {
+	safeOriginNets := make(netList, 0, len(conf.Conf.AnonCIDRs))
+
+	for _, cidr := range conf.Conf.AnonCIDRs {
+		_, net, err := net.ParseCIDR(cidr)
+
+		if err != nil {
+			log.Printf("ignoring invalid cidr: %s", err)
+			continue
+		}
+
+		safeOriginNets = append(safeOriginNets, *net)
+	}
+
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		user := r.Context().Value(ContextKey("user")).(string)
+
+		originIP, err := getOriginIP(r)
+
+		if err != nil {
+			log.Printf("unable to check origin ip: %s", err)
+			http.Redirect(w, r, redirect, http.StatusTemporaryRedirect)
+			return
+		}
+
+		log.Printf("origin ip: %s", originIP)
+		safeOrigin := safeOriginNets.Contains(originIP)
+
+		if user == "anon" && !safeOrigin {
+			http.Redirect(w, r, redirect, http.StatusTemporaryRedirect)
+			return
+		}
+		next.ServeHTTP(w, r)
+	})
+}
+
+// Get the origin ip from the x-forwarded-for header, or the source of
+// the request if not available
+func getOriginIP(r *http.Request) (net.IP, error) {
+	sourceIpHeader, ok := r.Header[http.CanonicalHeaderKey(ipHeader)]
+
+	if !ok {
+		addrParts := strings.Split(r.RemoteAddr, ":")
+
+		if len(addrParts) == 0 {
+			return nil, errors.New("no source ip available")
+		}
+
+		ip := net.ParseIP(addrParts[0])
+		if ip == nil {
+			return nil, fmt.Errorf("ip could not be parsed: %s", addrParts[0])
+		}
+		return ip, nil
+	}
+
+	if len(sourceIpHeader) != 1 {
+		return nil, fmt.Errorf("header has more than 1 value: %s=%v", ipHeader, sourceIpHeader)
+	}
+
+	ips := strings.Split(sourceIpHeader[0], ",")
+	ip := net.ParseIP(ips[0])
+	if ip == nil {
+		return nil, fmt.Errorf("not parseable as ip: %s", ips[0])
+	}
+
+	return ip, nil
+}

internal/middleware/session.go

@@ -4,7 +4,12 @@ package middleware
 import (
 	"context"
 	"crypto/rand"
+	"log"
 	"net/http"
+
+	urls "forgejo.gwairfelin.com/max/gispatcho"
+	"forgejo.gwairfelin.com/max/gonotes/internal/auth"
+	"golang.org/x/oauth2"
 )
 
 type Session struct {
@@ -13,14 +18,29 @@ type Session struct {
 
 type SessionStore struct {
 	sessions map[string]Session
+	oauth    *oauth2.Config
+	Routes   urls.URLs
 }
 
 type ContextKey string
 
-func NewSessionStore() SessionStore {
-	return SessionStore{sessions: make(map[string]Session, 10)}
+func NewSessionStore(oauth *oauth2.Config, prefix string) SessionStore {
+	store := SessionStore{
+		sessions: make(map[string]Session, 10),
+		oauth:    oauth,
+	}
+	store.Routes = urls.URLs{
+		Prefix: prefix,
+		URLs: map[string]urls.URL{
+			"login":    {Path: "/login/", Protocol: "GET", Handler: store.LoginViewOAUTH},
+			"callback": {Path: "/callback/", Protocol: "GET", Handler: store.CallbackViewOAUTH},
+			"logout":   {Path: "/logout/", Protocol: "GET", Handler: store.LogoutView},
+		},
+	}
+	return store
 }
 
+// Log a user in
 func (s *SessionStore) Login(user string, w http.ResponseWriter) string {
 	sessionID := rand.Text()
 	s.sessions[sessionID] = Session{User: user}
@@ -34,7 +54,8 @@ func (s *SessionStore) Login(user string, w http.ResponseWriter) string {
 	return sessionID
 }
 
-func (s *SessionStore) Logout(w http.ResponseWriter, r *http.Request) {
+// View to logout a user
+func (s *SessionStore) LogoutView(w http.ResponseWriter, r *http.Request) {
 	session := r.Context().Value(ContextKey("session")).(string)
 
 	delete(s.sessions, session)
@@ -44,42 +65,68 @@ func (s *SessionStore) Logout(w http.ResponseWriter, r *http.Request) {
 	}
 
 	http.SetCookie(w, &cookie)
+	http.Redirect(w, r, "/", http.StatusTemporaryRedirect)
 }
 
+// View to log in a user via oauth
+func (s *SessionStore) LoginViewOAUTH(w http.ResponseWriter, r *http.Request) {
+	log.Printf("%+v", *s.oauth)
+
+	oauthState := auth.GenerateStateOAUTHCookie(w, s.Routes.Prefix)
+
+	url := s.oauth.AuthCodeURL(oauthState)
+	log.Printf("Redirecting to %s", url)
+	http.Redirect(w, r, url, http.StatusTemporaryRedirect)
+}
+
+// Oauth callback view
+func (s *SessionStore) CallbackViewOAUTH(w http.ResponseWriter, r *http.Request) {
+	// Read oauthState from Cookie
+	oauthState, err := r.Cookie("oauthstate")
+	if err != nil {
+		log.Printf("An error occured during login: %s", err)
+		http.Redirect(w, r, "/", http.StatusTemporaryRedirect)
+		return
+	}
+
+	log.Printf("%v", oauthState)
+
+	if r.FormValue("state") != oauthState.Value {
+		log.Println("invalid oauth state")
+		http.Redirect(w, r, "/", http.StatusTemporaryRedirect)
+		return
+	}
+
+	username, err := auth.GetUserFromForgejo(r.FormValue("code"), s.oauth)
+	if err != nil {
+		log.Println(err.Error())
+		http.Redirect(w, r, "/", http.StatusTemporaryRedirect)
+		return
+	}
+
+	s.Login(username, w)
+	http.Redirect(w, r, "/", http.StatusTemporaryRedirect)
+}
+
+// Turn the session store into a middleware.
+// Sets the user on the context based on the available session cookie
 func (s *SessionStore) AsMiddleware(next http.Handler) http.Handler {
 	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		sessionCookie, err := r.Cookie("id")
-		// No session yet
-		if err != nil {
-			user := r.Header.Get("X-Auth-Request-User")
+		user := "anon"
+		var cookieVal string
+		// Session exists
+		if err == nil {
+			session, ok := s.sessions[sessionCookie.Value]
 
-			if user != "" {
-				sessionID := s.Login(user, w)
-				nextWithSessionContext(w, r, next, user, sessionID)
-			} else {
-				http.Redirect(w, r, "/login/", http.StatusFound)
+			// Session not expired
+			if ok {
+				user = session.User
+				cookieVal = sessionCookie.Value
 			}
-
-			return
 		}
 
-		session, ok := s.sessions[sessionCookie.Value]
-
-		// Session expired
-		if !ok {
-			user := r.Header.Get("X-Auth-Request-User")
-
-			if user != "" {
-				sessionID := s.Login(user, w)
-				nextWithSessionContext(w, r, next, user, sessionID)
-			} else {
-				http.Redirect(w, r, "/login/", http.StatusFound)
-			}
-
-			return
-		}
-
-		nextWithSessionContext(w, r, next, session.User, sessionCookie.Value)
+		nextWithSessionContext(w, r, next, user, cookieVal)
 	})
 }
 

internal/notes/notes.go

@@ -5,13 +5,16 @@ package notes
 import (
 	"bufio"
 	"bytes"
+	"cmp"
 	"crypto/rand"
 	"errors"
 	"fmt"
 	"html/template"
 	"log"
+	"maps"
 	"os"
 	"path/filepath"
+	"slices"
 	"strings"
 	"time"
 
@@ -98,14 +101,26 @@ func Init() error {
 	return nil
 }
 
+func (ns *noteSet) Sort() []*Note {
+	orderByTitle := func(a, b *Note) int {
+		return cmp.Compare(a.Title, b.Title)
+	}
+	return slices.SortedFunc(maps.Keys(*ns), orderByTitle)
+}
+
 func (ns *NoteStore) Get(owner string) noteSet {
 	return ns.notes[owner]
 }
 
+func (ns *NoteStore) GetOrdered(owner string) []*Note {
+	notes := ns.Get(owner)
+	return notes.Sort()
+}
+
 func (ns *NoteStore) GetOne(owner string, uid string) (*Note, bool) {
 	notes := ns.Get(owner)
 
-	for note, _ := range notes {
+	for note := range notes {
 		if note.Uid == uid {
 			log.Printf("Found single note during GetOne %s", note.Title)
 			return note, true
@@ -121,8 +136,9 @@ func (ns *NoteStore) Add(note *Note, user string) {
 	ns.notes[user][note] = true
 }
 
-func (ns *NoteStore) Del(note *Note, user string) {
+func (ns *NoteStore) Del(note *Note, user string) error {
 	delete(ns.notes[user], note)
+	return note.Delete()
 }
 
 func (ns *NoteStore) UserTags(user string) []string {
@@ -145,13 +161,7 @@ func (ns *NoteStore) UserTags(user string) []string {
 
 	log.Printf("Tagset is %v", tagSet)
 
-	tags := make([]string, len(tagSet))
-	i := 0
-	for tag := range tagSet {
-		tags[i] = tag
-		i++
-	}
-	return tags
+	return slices.Sorted(maps.Keys(tagSet))
 }
 
 func fmtPath(path string) string {
@@ -331,8 +341,8 @@ func (n *Note) DelViewer(viewer string) {
 	delete(n.Viewers, viewer)
 }
 
-func DeleteNote(uid string) error {
-	filename := filepath.Join(conf.Conf.NotesDir, fmtPath(uid))
+func (n *Note) Delete() error {
+	filename := filepath.Join(conf.Conf.NotesDir, fmtPath(n.Uid))
 	return os.Remove(filename)
 }
 
@@ -408,10 +418,5 @@ func (n *Note) ToggleBox(nthBox int) (bool, bool) {
 }
 
 func (n *Note) HasTag(tag string) bool {
-	for _, tag_ := range n.Tags {
-		if tag_ == tag {
-			return true
-		}
-	}
-	return false
+	return slices.Contains(n.Tags, tag)
 }

internal/notes/views/views.go

@@ -107,10 +107,18 @@ func new(w http.ResponseWriter, r *http.Request) {
 }
 
 func delete(w http.ResponseWriter, r *http.Request) {
-	// user := r.Context().Value(middleware.ContextKey("user")).(string)
+	user := r.Context().Value(middleware.ContextKey("user")).(string)
+
+	uid := r.PathValue("note")
+
+	note, ok := notes.Notes.GetOne(user, uid)
+
+	if !ok {
+		http.NotFound(w, r)
+	}
+
+	err := notes.Notes.Del(note, user)
 
-	encodedTitle := r.PathValue("note")
-	err := notes.DeleteNote(encodedTitle)
 	if err != nil {
 		log.Print(err.Error())
 		http.Error(w, "Couldn't delete note", http.StatusInternalServerError)
@@ -215,11 +223,11 @@ func list(w http.ResponseWriter, r *http.Request) {
 
 	titlesAndUrls := make([]titleAndURL, 0)
 
-	ns := notes.Notes.Get(user)
+	ns := notes.Notes.GetOrdered(user)
 	log.Printf("Notes: %+v", notes.Notes)
 	log.Printf("Notes for %s: %+v", user, ns)
 
-	for note := range ns {
+	for _, note := range ns {
 		if tag == "" || note.HasTag(tag) {
 			titlesAndUrls = append(
 				titlesAndUrls,