feat(dav): accept Bearer access tokens on WebDAV auth (#3548)

WebDAVAuth now falls back to the API JWT verifier when no Basic
credentials are present, mounting token users at their 'my' root.
OIDC-only users and API clients (rclone, davfs2, ChromeOS Files) no
longer need a separate DAV password.

- WWW-Authenticate advertises both Basic and Bearer
- Scoped client tokens need Files.Read; missing Files.Write confines
  to read-only alongside the group/account read-only bits
- Unguarded DavAccounts[0] accesses len-guarded for account-less users
- stripPrefix defaults the mount root to cloudreve://my when no dav
  account exists

IdP-token introspection (option 2 of the upstream request) is not
included; it needs JWKS/userinfo plumbing against the provider.

middleware/auth.go

@@ -3,6 +3,7 @@ package middleware
 import (
 	"crypto/subtle"
 	"net/http"
+	"strings"
 
 	"github.com/cloudreve/Cloudreve/v4/application/dependency"
 	"github.com/cloudreve/Cloudreve/v4/ent"
@@ -104,23 +105,55 @@ func LoginRequired() gin.HandlerFunc {
 // WebDAVAuth 验证WebDAV登录及权限
 func WebDAVAuth() gin.HandlerFunc {
 	return func(c *gin.Context) {
+		dep := dependency.FromContext(c)
+		l := dep.Logger()
+
 		username, password, ok := c.Request.BasicAuth()
+		var expectedUser *ent.User
+		bearerAuth := false
 		if !ok {
+			// Bearer auth: accept Cloudreve API access tokens so OIDC-only
+			// users and API clients can mount without a DAV password (#3548).
+			if !strings.HasPrefix(c.GetHeader(auth.AuthorizationHeader), auth.TokenHeaderPrefix) {
 				// OPTIONS 请求不需要鉴权
 				if c.Request.Method == http.MethodOptions {
 					c.Next()
 					return
 				}
-			c.Writer.Header()["WWW-Authenticate"] = []string{`Basic realm="cloudreve"`}
+				c.Writer.Header().Add("WWW-Authenticate", `Basic realm="cloudreve"`)
+				c.Writer.Header().Add("WWW-Authenticate", `Bearer realm="cloudreve"`)
 				c.Status(http.StatusUnauthorized)
 				c.Abort()
 				return
 			}
 
-		dep := dependency.FromContext(c)
-		l := dep.Logger()
+			if _, err := dep.TokenAuth().VerifyAndRetrieveUser(c); err != nil {
+				l.Debug("WebDAVAuth: bearer token rejected: %s", err)
+				c.Status(http.StatusUnauthorized)
+				c.Abort()
+				return
+			}
+
+			uid := inventory.UserIDFromContext(c)
+			if uid == 0 {
+				c.Status(http.StatusUnauthorized)
+				c.Abort()
+				return
+			}
+
+			if err := SetUserCtx(c, uid); err != nil {
+				l.Debug("WebDAVAuth: failed to load bearer user %d: %s", uid, err)
+				c.Status(http.StatusUnauthorized)
+				c.Abort()
+				return
+			}
+
+			expectedUser = inventory.UserFromContext(c)
+			bearerAuth = true
+		} else {
 			userClient := dep.UserClient()
-		expectedUser, err := userClient.GetActiveByDavAccount(c, username, password)
+			var err error
+			expectedUser, err = userClient.GetActiveByDavAccount(c, username, password)
 			if err != nil {
 				if username == "" {
 					if u, err := userClient.GetByEmail(c, username); err == nil {
@@ -143,6 +176,7 @@ func WebDAVAuth() gin.HandlerFunc {
 				c.Abort()
 				return
 			}
+		}
 
 		// 用户组已启用WebDAV？
 		group, err := expectedUser.Edges.GroupOrErr()
@@ -160,9 +194,27 @@ func WebDAVAuth() gin.HandlerFunc {
 			return
 		}
 
+		// Scoped client tokens need at least Files.Read; tokens without
+		// Files.Write are confined to read-only access.
+		if bearerAuth {
+			if err := auth.CheckScope(c, types.ScopeFilesRead); err != nil {
+				c.Status(http.StatusForbidden)
+				c.Abort()
+				return
+			}
+		}
+
 		// 检查是否只读
-		if expectedUser.Edges.DavAccounts[0].Options.Enabled(int(types.DavAccountReadOnly)) ||
-			group.Permissions.Enabled(int(types.GroupPermissionWebDAVReadOnly)) {
+		readOnly := group.Permissions.Enabled(int(types.GroupPermissionWebDAVReadOnly))
+		if len(expectedUser.Edges.DavAccounts) > 0 &&
+			expectedUser.Edges.DavAccounts[0].Options.Enabled(int(types.DavAccountReadOnly)) {
+			readOnly = true
+		}
+		if bearerAuth && auth.CheckScope(c, types.ScopeFilesWrite) != nil {
+			readOnly = true
+		}
+
+		if readOnly {
 			switch c.Request.Method {
 			case http.MethodDelete, http.MethodPut, "MKCOL", "COPY", "MOVE", "LOCK", "UNLOCK", "PROPPATCH":
 				c.Status(http.StatusForbidden)
@@ -171,7 +223,9 @@ func WebDAVAuth() gin.HandlerFunc {
 			}
 		}
 
+		if !bearerAuth {
 			SetUserCtxByUser(c, expectedUser)
+		}
 		c.Next()
 	}
 }

middleware/davbearer_test.go

@@ -0,0 +1,194 @@
+package middleware
+
+import (
+	"context"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/cloudreve/Cloudreve/v4/application/dependency"
+	"github.com/cloudreve/Cloudreve/v4/ent/enttest"
+	"github.com/cloudreve/Cloudreve/v4/inventory"
+	"github.com/cloudreve/Cloudreve/v4/inventory/types"
+	"github.com/cloudreve/Cloudreve/v4/pkg/auth"
+	"github.com/cloudreve/Cloudreve/v4/pkg/boolset"
+	"github.com/cloudreve/Cloudreve/v4/pkg/cache"
+	"github.com/cloudreve/Cloudreve/v4/pkg/logging"
+	"github.com/cloudreve/Cloudreve/v4/pkg/util"
+	"github.com/gin-gonic/gin"
+)
+
+type stubTokenAuth struct {
+	uid    int
+	scopes []string
+}
+
+func (s stubTokenAuth) Issue(ctx context.Context, args *auth.IssueTokenArgs) (*auth.Token, error) {
+	return nil, nil
+}
+
+func (s stubTokenAuth) VerifyAndRetrieveUser(c *gin.Context) (bool, error) {
+	if c.GetHeader(auth.AuthorizationHeader) == "Bearer good" {
+		util.WithValue(c, inventory.UserIDCtx{}, s.uid)
+		if s.scopes != nil {
+			util.WithValue(c, auth.ScopeContextKey{}, s.scopes)
+		}
+	}
+	return false, nil
+}
+
+func (s stubTokenAuth) Refresh(ctx context.Context, refreshToken string) (*auth.Token, error) {
+	return nil, nil
+}
+
+func (s stubTokenAuth) Claims(ctx context.Context, tokenStr string) (*auth.Claims, error) {
+	return nil, nil
+}
+
+func newDavAuthDep(t *testing.T, groupPerms *boolset.BooleanSet, scopes []string) dependency.Dep {
+	t.Helper()
+	client := enttest.Open(t, "sqlite3", "file:ent?mode=memory&_fk=1")
+	t.Cleanup(func() { client.Close() })
+
+	group := client.Group.Create().
+		SetName("g").
+		SetPermissions(groupPerms).
+		SaveX(context.Background())
+
+	u := client.User.Create().
+		SetEmail("dav@test.com").
+		SetNick("dav").
+		SetStatus("active").
+		SetPassword("x").
+		SetGroup(group).
+		SaveX(context.Background())
+
+	return dependency.NewDependency(
+		dependency.WithKV(cache.NewMemoStore("", nil)),
+		dependency.WithLogger(logging.NewConsoleLogger(logging.LevelDebug)),
+		dependency.WithUserClient(inventory.NewUserClient(client)),
+		dependency.WithTokenAuth(stubTokenAuth{uid: u.ID, scopes: scopes}),
+	)
+}
+
+func newDavRequest(t *testing.T, dep dependency.Dep, method, authHeader string) (*gin.Context, *httptest.ResponseRecorder) {
+	t.Helper()
+	w := httptest.NewRecorder()
+	c := gin.CreateTestContextOnly(w, testEngine)
+	req := httptest.NewRequest(method, "/dav/file.txt", nil)
+	if authHeader != "" {
+		req.Header.Set("Authorization", authHeader)
+	}
+	c.Request = req.WithContext(context.WithValue(req.Context(), dependency.DepCtx{}, dep))
+	return c, w
+}
+
+func TestWebDAVBearerAuth(t *testing.T) {
+	gin.SetMode(gin.TestMode)
+	handler := WebDAVAuth()
+
+	davPerms := &boolset.BooleanSet{}
+	boolset.Set(int(types.GroupPermissionWebDAV), true, davPerms)
+	readOnlyPerms := &boolset.BooleanSet{}
+	boolset.Set(int(types.GroupPermissionWebDAV), true, readOnlyPerms)
+	boolset.Set(int(types.GroupPermissionWebDAVReadOnly), true, readOnlyPerms)
+
+	t.Run("valid bearer token authenticates", func(t *testing.T) {
+		dep := newDavAuthDep(t, davPerms, nil)
+		c, _ := newDavRequest(t, dep, http.MethodGet, "Bearer good")
+		handler(c)
+		if c.IsAborted() {
+			t.Fatal("valid bearer token was rejected")
+		}
+		u := inventory.UserFromContext(c)
+		if u == nil || u.Email != "dav@test.com" {
+			t.Fatalf("expected bearer user in ctx, got %+v", u)
+		}
+	})
+
+	t.Run("invalid bearer token rejected", func(t *testing.T) {
+		dep := newDavAuthDep(t, davPerms, nil)
+		c, _ := newDavRequest(t, dep, http.MethodGet, "Bearer bad")
+		handler(c)
+		if !c.IsAborted() || c.Writer.Status() != http.StatusUnauthorized {
+			t.Fatalf("expected 401, got %d", c.Writer.Status())
+		}
+	})
+
+	t.Run("no credentials still issues basic+bearer challenge", func(t *testing.T) {
+		dep := newDavAuthDep(t, davPerms, nil)
+		c, w := newDavRequest(t, dep, http.MethodGet, "")
+		handler(c)
+		if c.Writer.Status() != http.StatusUnauthorized {
+			t.Fatalf("expected 401, got %d", c.Writer.Status())
+		}
+		if challenges := w.Header().Values("WWW-Authenticate"); len(challenges) != 2 {
+			t.Fatalf("expected Basic+Bearer challenges, got %v", challenges)
+		}
+	})
+
+	t.Run("options without credentials passes", func(t *testing.T) {
+		dep := newDavAuthDep(t, davPerms, nil)
+		c, _ := newDavRequest(t, dep, http.MethodOptions, "")
+		handler(c)
+		if c.IsAborted() {
+			t.Fatal("unauthenticated OPTIONS was rejected")
+		}
+	})
+
+	t.Run("bearer user without group dav permission forbidden", func(t *testing.T) {
+		dep := newDavAuthDep(t, &boolset.BooleanSet{}, nil)
+		c, _ := newDavRequest(t, dep, http.MethodGet, "Bearer good")
+		handler(c)
+		if c.Writer.Status() != http.StatusForbidden {
+			t.Fatalf("expected 403, got %d", c.Writer.Status())
+		}
+	})
+
+	t.Run("group read-only blocks bearer writes", func(t *testing.T) {
+		dep := newDavAuthDep(t, readOnlyPerms, nil)
+		c, _ := newDavRequest(t, dep, http.MethodPut, "Bearer good")
+		handler(c)
+		if c.Writer.Status() != http.StatusForbidden {
+			t.Fatalf("expected 403 for PUT, got %d", c.Writer.Status())
+		}
+		c, _ = newDavRequest(t, dep, http.MethodGet, "Bearer good")
+		handler(c)
+		if c.IsAborted() {
+			t.Fatal("read-only bearer GET was rejected")
+		}
+	})
+
+	t.Run("scoped token without Files.Write is read-only", func(t *testing.T) {
+		dep := newDavAuthDep(t, davPerms, []string{types.ScopeFilesRead})
+		c, _ := newDavRequest(t, dep, http.MethodDelete, "Bearer good")
+		handler(c)
+		if c.Writer.Status() != http.StatusForbidden {
+			t.Fatalf("expected 403 for DELETE, got %d", c.Writer.Status())
+		}
+		c, _ = newDavRequest(t, dep, http.MethodGet, "Bearer good")
+		handler(c)
+		if c.IsAborted() {
+			t.Fatal("scoped read token GET was rejected")
+		}
+	})
+
+	t.Run("scoped token without Files.Read forbidden", func(t *testing.T) {
+		dep := newDavAuthDep(t, davPerms, []string{"User.Read"})
+		c, _ := newDavRequest(t, dep, http.MethodGet, "Bearer good")
+		handler(c)
+		if c.Writer.Status() != http.StatusForbidden {
+			t.Fatalf("expected 403, got %d", c.Writer.Status())
+		}
+	})
+
+	t.Run("basic auth path unchanged", func(t *testing.T) {
+		dep := newDavAuthDep(t, davPerms, nil)
+		c, _ := newDavRequest(t, dep, http.MethodGet, "Basic dGVzdDp0ZXN0")
+		handler(c)
+		// No dav account exists -> 401 via the basic credential path.
+		if c.Writer.Status() != http.StatusUnauthorized {
+			t.Fatalf("expected 401, got %d", c.Writer.Status())
+		}
+	})
+}

pkg/webdav/webdav.go

@@ -41,7 +41,13 @@ const (
 )
 
 func stripPrefix(p string, u *ent.User) (string, *fs.URI, int, error) {
-	base, err := fs.NewUriFromString(u.Edges.DavAccounts[0].URI)
+	// Bearer-authenticated users carry no dav account; mount them at their
+	// "my" root. Basic-auth users keep their configured mount point (#3548).
+	baseUri := fs.NewMyUri("")
+	if len(u.Edges.DavAccounts) > 0 {
+		baseUri = u.Edges.DavAccounts[0].URI
+	}
+	base, err := fs.NewUriFromString(baseUri)
 	if err != nil {
 		return "", nil, http.StatusInternalServerError, err
 	}
@@ -262,7 +268,8 @@ func handlePut(c *gin.Context, user *ent.User, fm manager.FileManager) (status i
 		return purposeStatusCodeFromError(err), err
 	}
 
-	if user.Edges.DavAccounts[0].Options.Enabled(int(types.DavAccountDisableSysFiles)) {
+	if len(user.Edges.DavAccounts) > 0 &&
+		user.Edges.DavAccounts[0].Options.Enabled(int(types.DavAccountDisableSysFiles)) {
 		if strings.HasPrefix(reqPath.Name(), ".") {
 			return http.StatusMethodNotAllowed, nil
 		}
@@ -560,7 +567,8 @@ func handleGetHeadPost(c *gin.Context, user *ent.User, fm manager.FileManager) (
 
 	es.Apply(entitysource.WithSpeedLimit(int64(user.Edges.Group.SpeedLimit)))
 	if es.ShouldInternalProxy() ||
-		(user.Edges.DavAccounts[0].Options.Enabled(int(types.DavAccountProxy)) &&
+		(len(user.Edges.DavAccounts) > 0 &&
+			user.Edges.DavAccounts[0].Options.Enabled(int(types.DavAccountProxy)) &&
 			user.Edges.Group.Permissions.Enabled(int(types.GroupPermissionWebDAVProxy))) {
 		es.Serve(c.Writer, c.Request)
 	} else {