Implement initial login functionality

internal/dis/component/auth/auth.go

@@ -0,0 +1,23 @@
+package auth
+
+import (
+	"sync"
+
+	"github.com/FAU-CDI/wisski-distillery/internal/dis/component"
+	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/sql"
+	"github.com/gorilla/sessions"
+)
+
+type Auth struct {
+	component.Base
+	Dependencies struct {
+		SQL *sql.SQL
+	}
+
+	storeOnce sync.Once
+	store     sessions.Store
+}
+
+var (
+	_ component.Routeable = (*Auth)(nil)
+)

internal/dis/component/auth/templates/login.html

@@ -0,0 +1,31 @@
+{{ template "_base.html" . }}
+{{ define "title" }}Login{{ end }}
+
+{{ define "header/time" }}
+<!-- no header/time -->
+{{ end }}
+{{ define "header"}}
+<!-- no header -->
+{{ end }}
+
+{{ define "content" }}
+<div class="pure-u-1">
+
+    {{ if .Message }}
+        <div>
+            {{ .Message }}
+        </div>
+    {{ end }}
+
+    <form class="pure-form" method="POST">
+        <fieldset>
+            <legend>Login Required</legend>
+
+            <input type="text" name="username">
+            <input type="password" name="password">
+            <input type="submit" value="Login">
+        </fieldset>
+    </form>
+</div>
+
+{{ end }}

internal/dis/component/auth/user.go

@@ -0,0 +1,176 @@
+package auth
+
+import (
+	"context"
+	"errors"
+	"fmt"
+
+	"github.com/FAU-CDI/wisski-distillery/internal/models"
+	"golang.org/x/crypto/bcrypt"
+)
+
+// ErrUserNotFound is returned when a user is not found
+var ErrUserNotFound = errors.New("user not found")
+
+// Users returns all users in the database
+func (auth *Auth) Users(ctx context.Context) (users []*AuthUser, err error) {
+	// query the user table
+	table, err := auth.Dependencies.SQL.QueryTable(ctx, false, models.UserTable)
+	if err != nil {
+		return
+	}
+
+	// find all the users
+	var dUsers []models.User
+	err = table.Find(&dUsers).Error
+	if err != nil {
+		return nil, err
+	}
+
+	// and map them to high-level user objects
+	users = make([]*AuthUser, len(dUsers))
+	for i, user := range dUsers {
+		users[i] = &AuthUser{
+			User: user,
+			auth: auth,
+		}
+	}
+
+	return users, nil
+}
+
+// User returns a single user.
+// If the user does not exist, returns ErrUserNotFound.
+func (auth *Auth) User(ctx context.Context, name string) (user *AuthUser, err error) {
+	// quick and dirty check for the empty username (which is not allowed)
+	if name == "" {
+		return nil, ErrUserNotFound
+	}
+
+	// return the user
+	table, err := auth.Dependencies.SQL.QueryTable(ctx, false, models.UserTable)
+	if err != nil {
+		return
+	}
+
+	user = &AuthUser{}
+
+	// find the user
+	res := table.Where(&models.User{User: name}).Find(&user.User)
+	err = res.Error
+	if err != nil {
+		return
+	}
+
+	// check if the user was not found
+	if res.RowsAffected == 0 {
+		return nil, ErrUserNotFound
+	}
+
+	user.auth = auth
+
+	return
+}
+
+// CreateUser creates a new user and returns it.
+// The user is not associated to any WissKIs, and has no password set.
+func (auth *Auth) CreateUser(ctx context.Context, name string) (user *AuthUser, err error) {
+	// return the user
+	table, err := auth.Dependencies.SQL.QueryTable(ctx, false, models.UserTable)
+	if err != nil {
+		return
+	}
+
+	user = &AuthUser{
+		User: models.User{
+			User:    name,
+			Enabled: false,
+		},
+	}
+
+	// do the create statement
+	err = table.Create(&user.User).Error
+	if err != nil {
+		return nil, err
+	}
+
+	user.auth = auth
+	return user, nil
+}
+
+// AuthUser represents an authorized user
+type AuthUser struct {
+	auth *Auth
+	models.User
+}
+
+func (au AuthUser) String() string {
+	hasPassword := len(au.PasswordHash) > 0
+	return fmt.Sprintf("User{Name:%q,Enabled:%t,HasPassword:%t,Admin:%t}", au.User.User, au.User.Enabled, hasPassword, au.User.Admin)
+}
+
+// SetPassword sets the password for this user and turns the user on
+func (au *AuthUser) SetPassword(ctx context.Context, password []byte) (err error) {
+	au.User.PasswordHash, err = bcrypt.GenerateFromPassword(password, bcrypt.DefaultCost)
+	if err != nil {
+		return err
+	}
+	au.User.Enabled = true
+	return au.Save(ctx)
+}
+
+// UnsetPassword removes the password from this user, and disables them
+func (au *AuthUser) UnsetPassword(ctx context.Context) error {
+	au.User.PasswordHash = nil
+	au.User.Enabled = false
+	return au.Save(ctx)
+}
+
+var ErrUserDisabled = errors.New("user is disabled")
+var ErrUserBlank = errors.New("user has no password set")
+
+// CheckPassword checks if this user can login with the provided password.
+// Returns nil on success, an error otherwise.
+func (au *AuthUser) CheckPassword(ctx context.Context, password []byte) error {
+	if !au.User.Enabled {
+		return ErrUserDisabled
+	}
+
+	if len(au.User.PasswordHash) == 0 {
+		return ErrUserDisabled
+	}
+
+	return bcrypt.CompareHashAndPassword(au.User.PasswordHash, password)
+}
+
+// MakeAdmin makes this user an admin, and saves the update in the database.
+// If the user is already an admin, does not return an error.
+func (au *AuthUser) MakeAdmin(ctx context.Context) error {
+	au.User.Admin = true
+	return au.Save(ctx)
+}
+
+// MakeRegular removes admin rights from this user.
+// If this user is not an dmin, does not return an error.
+func (au *AuthUser) MakeRegular(ctx context.Context) error {
+	au.User.Admin = true
+	return au.Save(ctx)
+}
+
+// Save saves the given user in the database
+func (au *AuthUser) Save(ctx context.Context) error {
+	table, err := au.auth.Dependencies.SQL.QueryTable(ctx, false, models.UserTable)
+	if err != nil {
+		return err
+	}
+	return table.Save(&au.User).Error
+}
+
+// Delete deletes the user from the database
+func (au *AuthUser) Delete(ctx context.Context) error {
+	table, err := au.auth.Dependencies.SQL.QueryTable(ctx, false, models.UserTable)
+	if err != nil {
+		return err
+	}
+	return table.Delete(&au.User).Error
+}

internal/dis/component/auth/web.go

@@ -0,0 +1,260 @@
+package auth
+
+import (
+	"context"
+	"net/http"
+	"net/url"
+
+	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/control/static"
+	"github.com/FAU-CDI/wisski-distillery/pkg/httpx"
+	"github.com/gorilla/sessions"
+	"github.com/julienschmidt/httprouter"
+
+	_ "embed"
+)
+
+func (auth *Auth) Routes() []string {
+	return []string{"/auth/"}
+}
+
+type contextUserKey struct{}
+
+var ctxUserKey = contextUserKey{}
+
+const (
+	sessionCookieName = "distillery-session"
+	sessionUserKey    = "user"
+)
+
+// session returns the session belonging to a request
+func (auth *Auth) session(r *http.Request) (*sessions.Session, error) {
+	auth.storeOnce.Do(func() {
+		auth.store = sessions.NewCookieStore([]byte(auth.Config.SessionSecret))
+	})
+	return auth.store.Get(r, sessionCookieName)
+}
+
+// UserOf returns the user logged into the given request.
+// If there is no user associated with the given user, user and error will be nil.
+//
+// When no UserOf exists in the given session returns nil.
+// An invalid session (for a UserOf)
+func (auth *Auth) UserOf(r *http.Request) (user *AuthUser, err error) {
+	ctx := r.Context()
+	if user, ok := ctx.Value(ctxUserKey).(*AuthUser); ok && user != nil {
+		return user, nil
+	}
+
+	// first read the session
+	sess, err := auth.session(r)
+	if err != nil {
+		return nil, err
+	}
+
+	// try to read the name from the session
+	name, ok := sess.Values[sessionUserKey]
+	if !ok {
+		return nil, nil
+	}
+	nameS, ok := name.(string)
+	if !ok || nameS == "" {
+		return nil, nil
+	}
+
+	// fetch the user, check if they still exist
+	user, err = auth.User(ctx, nameS)
+	if err == ErrUserNotFound {
+		return nil, nil
+	}
+	if err != nil {
+		return nil, err
+	}
+
+	// user isn't enabled
+	if !user.Enabled {
+		return nil, nil
+	}
+
+	// get the user
+	return user, nil
+}
+
+// writeLogin marks the user as logged in on the given writer
+func (auth *Auth) writeLogin(w http.ResponseWriter, r *http.Request, user *AuthUser) error {
+	sess, err := auth.session(r)
+	if err != nil {
+		return err
+	}
+	sess.Values[sessionUserKey] = user.User.User
+	return sess.Save(r, w)
+}
+
+// writeLogout logs out the user form the given session
+func (auth *Auth) writeLogout(w http.ResponseWriter, r *http.Request) error {
+	sess, err := auth.session(r)
+	if err != nil {
+		return err
+	}
+	sess.Options.MaxAge = -1
+	return sess.Save(r, w)
+}
+
+//go:embed "templates/login.html"
+var loginHTMLStr string
+var loginTemplate = static.AssetsAuthLogin.MustParseShared("login.html", loginHTMLStr)
+
+var loginResponse = httpx.Response{
+	ContentType: "text/plain",
+	Body:        []byte("user is signed in"),
+}
+
+// HandleRoute returns the handler for the requested route
+func (auth *Auth) HandleRoute(ctx context.Context, route string) (http.Handler, error) {
+	router := httprouter.New()
+
+	router.Handler(http.MethodGet, route, auth.Protect(loginResponse, nil))
+
+	router.HandlerFunc(http.MethodGet, route+"login", auth.loginRoute)
+	router.HandlerFunc(http.MethodPost, route+"login", auth.loginRoute)
+
+	router.HandlerFunc(http.MethodGet, route+"logout", auth.logoutRoute)
+
+	return router, nil
+}
+
+type loginContext struct {
+	Message string
+}
+
+// Protect returns a new handler which requires a user to be logged in and pass the perm function.
+//
+// If an unauthenticated user attempts to access the returned handler, they are redirected to the login endpoint.
+// When a user is logged in, and they pass the perm function (or the perm function is nil), the original handler is called.
+func (auth *Auth) Protect(handler http.Handler, perm func(user *AuthUser, r *http.Request) (ok bool, err error)) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		// load the user in the session
+		user, err := auth.UserOf(r)
+		if err != nil {
+			goto err
+		}
+
+		// if there is no user in the session
+		// we need to login the user
+		if user == nil {
+
+			// we can't redirect anything other than GET
+			// (because it might be a form)
+			// => so we just return a forbidden
+			if r.Method != http.MethodGet {
+				goto forbidden
+			}
+
+			// redirect the user to the login endpoint, with the original URI as a return
+			dest := "/auth/login?next=" + url.QueryEscape(r.URL.RequestURI())
+			http.Redirect(w, r, dest, http.StatusSeeOther)
+			return
+		}
+
+		// if we have a permission check, we need to call it
+		// to find out if the user is actually allowed to access the page
+		if perm != nil {
+			ok, err := perm(user, r)
+			if err != nil {
+				goto err
+			}
+			if !ok {
+				goto forbidden
+			}
+		}
+
+		// store the user into the session
+		r = r.WithContext(context.WithValue(r.Context(), ctxUserKey, user))
+		handler.ServeHTTP(w, r)
+		return
+	forbidden:
+		httpx.HTMLInterceptor.Intercept(w, r, httpx.ErrForbidden)
+		return
+	err:
+		httpx.HTMLInterceptor.Fallback.ServeHTTP(w, r)
+	})
+}
+
+func (auth *Auth) loginRoute(w http.ResponseWriter, r *http.Request) {
+	var message string
+
+	// try to read a user from the session
+	user, err := auth.UserOf(r)
+	if err != nil {
+		httpx.HTMLInterceptor.Fallback.ServeHTTP(w, r)
+		return
+	}
+
+	if user != nil {
+		goto success
+	}
+
+	switch r.Method {
+	default:
+		panic("never reached")
+	case http.MethodGet:
+		goto form
+	case http.MethodPost:
+		// parse the form!
+		if err := r.ParseForm(); err != nil {
+			message = "Login failed"
+			goto form
+		}
+
+		// get the username and password
+		username := r.Form.Get("username")
+		password := r.Form.Get("password")
+
+		// make sure that the user exists
+		user, err := auth.User(r.Context(), username)
+		if err != nil {
+			message = "Login failed"
+			goto form
+		}
+
+		// check the password (TODO: Support TOTP)
+		err = user.CheckPassword(r.Context(), []byte(password))
+		if err != nil {
+			message = "Login failed"
+			goto form
+		}
+
+		// and we logged the user in!
+		auth.writeLogin(w, r, user)
+		goto success
+	}
+
+form:
+	httpx.WriteHTML(loginContext{
+		Message: message,
+	}, nil, loginTemplate, "", w, r)
+	return
+success:
+	// get the destination
+	next := r.URL.Query().Get("next")
+	if next == "" || next[0] != '/' {
+		next = "/"
+	}
+
+	// and redirect to it!
+	http.Redirect(w, r, next, http.StatusSeeOther)
+}
+
+func (auth *Auth) logoutRoute(w http.ResponseWriter, r *http.Request) {
+	// do the logout
+	auth.writeLogout(w, r)
+
+	// get the destination
+	next := r.URL.Query().Get("next")
+	if next == "" || next[0] != '/' {
+		next = "/"
+	}
+
+	// and redirect to it!
+	http.Redirect(w, r, next, http.StatusSeeOther)
+
+}

internal/dis/component/control/control.go

@@ -16,8 +16,8 @@ import (
 type Control struct {
 	component.Base
 	Dependencies struct {
-		Servables []component.Servable
-		Cronables []component.Cronable
+		Routeables []component.Routeable
+		Cronables  []component.Cronable
 	}
 }
 

internal/dis/component/control/home/home.go

@@ -22,12 +22,12 @@ type Home struct {
 }
 
 var (
-	_ component.Servable = (*Home)(nil)
+	_ component.Routeable = (*Home)(nil)
 )
 
 func (*Home) Routes() []string { return []string{"/"} }
 
-func (home *Home) Handler(ctx context.Context, route string) (http.Handler, error) {
+func (home *Home) HandleRoute(ctx context.Context, route string) (http.Handler, error) {
 	return home, nil
 }
 

internal/dis/component/control/info/info.go

@@ -29,12 +29,12 @@ type Info struct {
 
 var (
 	_ component.DistilleryFetcher = (*Info)(nil)
-	_ component.Servable          = (*Info)(nil)
+	_ component.Routeable         = (*Info)(nil)
 )
 
 func (*Info) Routes() []string { return []string{"/dis/"} }
 
-func (info *Info) Handler(ctx context.Context, route string) (handler http.Handler, err error) {
+func (info *Info) HandleRoute(ctx context.Context, route string) (handler http.Handler, err error) {
 
 	router := httprouter.New()
 

internal/dis/component/control/server.go

@@ -5,6 +5,7 @@ import (
 	"io"
 	"net/http"
 
+	"github.com/FAU-CDI/wisski-distillery/pkg/cancel"
 	"github.com/rs/zerolog"
 )
 
@@ -12,20 +13,24 @@ import (
 // The server may spawn background tasks, but these should be terminated once context closes.
 //
 // Logging messages are directed to progress
-func (control *Control) Server(ctx context.Context, progress io.Writer) (*http.ServeMux, error) {
+func (control *Control) Server(ctx context.Context, progress io.Writer) (http.Handler, error) {
 	// create a new mux
 	mux := http.NewServeMux()
 
 	// add all the servable routes!
-	for _, s := range control.Dependencies.Servables {
+	for _, s := range control.Dependencies.Routeables {
 		for _, route := range s.Routes() {
 			zerolog.Ctx(ctx).Info().Str("component", s.Name()).Str("route", route).Msg("mounting route")
-			handler, err := s.Handler(ctx, route)
+			handler, err := s.HandleRoute(ctx, route)
 			if err != nil {
 				return nil, err
 			}
 			mux.Handle(route, handler)
 		}
 	}
-	return mux, nil
+
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		r = r.WithContext(cancel.ValuesOf(r.Context(), ctx))
+		mux.ServeHTTP(w, r)
+	}), nil
 }

internal/dis/component/control/static/assets.go

@@ -21,7 +21,7 @@ type Assets struct {
 	Styles  string // <link> tags inserted by the asset
 }
 
-//go:generate node build.mjs HomeHome ComponentsIndex ControlIndex ControlInstance InstanceComponentsIndex
+//go:generate node build.mjs HomeHome ComponentsIndex ControlIndex ControlInstance InstanceComponentsIndex AuthLogin
 
 // MustParse parses a new template from the given source
 // and calls [RegisterAssoc] on it.

internal/dis/component/control/static/assets_dist.go

@@ -31,3 +31,9 @@ var AssetsInstanceComponentsIndex = Assets{
 	Scripts: `<script type="module" src="/static/HomeHome.38d394c2.js"></script><script src="/static/HomeHome.38d394c2.js" nomodule="" defer></script><script type="module" src="/static/InstanceComponentsIndex.38d394c2.js"></script><script src="/static/InstanceComponentsIndex.38d394c2.js" nomodule="" defer></script>`,
 	Styles:  `<link rel="stylesheet" href="/static/HomeHome.a75f04fa.css"><link rel="stylesheet" href="/static/InstanceComponentsIndex.38d394c2.css">`,	
 }
+
+// AssetsAuthLogin contains assets for the 'AuthLogin' entrypoint.
+var AssetsAuthLogin = Assets{
+	Scripts: `<script type="module" src="/static/HomeHome.38d394c2.js"></script><script src="/static/HomeHome.38d394c2.js" nomodule="" defer></script><script type="module" src="/static/AuthLogin.38d394c2.js"></script><script src="/static/AuthLogin.38d394c2.js" nomodule="" defer></script>`,
+	Styles:  `<link rel="stylesheet" href="/static/HomeHome.a75f04fa.css"><link rel="stylesheet" href="/static/AuthLogin.38d394c2.css">`,	
+}

internal/dis/component/control/static/src/entry/AuthLogin/index.css

@@ -0,0 +1 @@
+/* nothing for now */

internal/dis/component/control/static/src/entry/AuthLogin/index.ts

@@ -0,0 +1 @@
+// nothing for now

internal/dis/component/control/static/static.go

@@ -15,7 +15,7 @@ type Static struct {
 }
 
 var (
-	_ component.Servable = (*Static)(nil)
+	_ component.Routeable = (*Static)(nil)
 )
 
 func (*Static) Routes() []string { return []string{"/static/"} }
@@ -23,7 +23,7 @@ func (*Static) Routes() []string { return []string{"/static/"} }
 //go:embed dist
 var staticFS embed.FS
 
-func (static *Static) Handler(ctx context.Context, route string) (http.Handler, error) {
+func (static *Static) HandleRoute(ctx context.Context, route string) (http.Handler, error) {
 	// take the filesystem
 	fs, err := fs.Sub(staticFS, "dist")
 	if err != nil {

internal/dis/component/resolver/resolver.go

@@ -28,13 +28,15 @@ type Resolver struct {
 }
 
 var (
-	_ component.Servable = (*Resolver)(nil)
-	_ component.Cronable = (*Resolver)(nil)
+	_ component.Routeable = (*Resolver)(nil)
+	_ component.Cronable  = (*Resolver)(nil)
 )
 
 func (resolver *Resolver) Routes() []string { return []string{"/go/", "/wisski/get/"} }
 
-func (resolver *Resolver) Handler(ctx context.Context, route string) (http.Handler, error) {
+func (resolver *Resolver) HandleRoute(ctx context.Context, route string) (http.Handler, error) {
+	logger := zerolog.Ctx(ctx)
+
 	var err error
 	return resolver.handler.Get(func() (p wdresolve.ResolveHandler) {
 		p.TrustXForwardedProto = true
@@ -47,13 +49,13 @@ func (resolver *Resolver) Handler(ctx context.Context, route string) (http.Handl
 		domainName := resolver.Config.DefaultDomain
 		if domainName != "" {
 			fallback.Data[fmt.Sprintf("^https?://(.*)\\.%s", regexp.QuoteMeta(domainName))] = fmt.Sprintf("https://$1.%s", domainName)
-			zerolog.Ctx(ctx).Info().Str("name", domainName).Msg("registering default domain")
+			logger.Info().Str("name", domainName).Msg("registering default domain")
 		}
 
 		// handle the extra domains!
 		for _, domain := range resolver.Config.SelfExtraDomains {
 			fallback.Data[fmt.Sprintf("^https?://(.*)\\.%s", regexp.QuoteMeta(domain))] = fmt.Sprintf("https://$1.%s", domainName)
-			zerolog.Ctx(ctx).Info().Str("name", domainName).Msg("registering legacy domain")
+			logger.Info().Str("name", domainName).Msg("registering legacy domain")
 		}
 
 		// resolve the prefixes

internal/dis/component/server.go

@@ -5,13 +5,13 @@ import (
 	"net/http"
 )
 
-// Servable is a component that is servable
-type Servable interface {
+// Routeable is a component that is servable
+type Routeable interface {
 	Component
 
 	// Routes returns the routes served by this servable
 	Routes() []string
 
-	// Handler returns the handler for the requested route
-	Handler(ctx context.Context, route string) (http.Handler, error)
+	// HandleRoute returns the handler for the requested route
+	HandleRoute(ctx context.Context, route string) (http.Handler, error)
 }

internal/dis/component/sql/update.go

@@ -103,6 +103,11 @@ func (sql *SQL) Update(ctx context.Context, progress io.Writer) error {
 			&models.Lock{},
 			models.LockTable,
 		},
+		{
+			"users",
+			&models.User{},
+			models.UserTable,
+		},
 	}
 
 	// migrate all of the tables!