admin/files: support %(theme)s variable in media file paths

authentik/admin/files/tests/test_validation.py

@@ -62,10 +62,10 @@ def test_sanitize_invalid_characters_raises(self):
             "test@file.png",  # @
             "test#file.png",  # #
             "test$file.png",  # $
-            "test%file.png",  # %
+            "test%file.png",  # % (but %(theme)s is allowed)
             "test&file.png",  # &
             "test*file.png",  # *
-            "test(file).png",  # parentheses
+            "test(file).png",  # parentheses (but %(theme)s is allowed)
             "test[file].png",  # brackets
             "test{file}.png",  # braces
         ]
@@ -108,3 +108,30 @@ def test_sanitize_too_long_component_raises(self):
 
         with self.assertRaises(ValidationError):
             validate_file_name(path)
+
+    def test_sanitize_theme_variable_valid(self):
+        """Test sanitizing filename with %(theme)s variable"""
+        # These should all be valid
+        validate_file_name("logo-%(theme)s.png")
+        validate_file_name("brand/logo-%(theme)s.svg")
+        validate_file_name("images/icon-%(theme)s.png")
+        validate_file_name("%(theme)s/logo.png")
+        validate_file_name("brand/%(theme)s/logo.png")
+
+    def test_sanitize_theme_variable_multiple(self):
+        """Test sanitizing filename with multiple %(theme)s variables"""
+        validate_file_name("%(theme)s/logo-%(theme)s.png")
+
+    def test_sanitize_theme_variable_invalid_format(self):
+        """Test that partial or malformed theme variables are rejected"""
+        invalid_paths = [
+            "test%(theme.png",  # missing )s
+            "test%theme)s.png",  # missing (
+            "test%(themes).png",  # wrong variable name
+            "test%(THEME)s.png",  # wrong case
+            "test%()s.png",  # empty variable name
+        ]
+
+        for path in invalid_paths:
+            with self.assertRaises(ValidationError):
+                validate_file_name(path)

authentik/admin/files/validation.py

@@ -12,6 +12,13 @@
 MAX_FILE_NAME_LENGTH = 1024
 MAX_PATH_COMPONENT_LENGTH = 255
 
+# Theme variable placeholder that can be used in file paths
+# This allows for theme-specific files like logo-%(theme)s.png
+THEME_VARIABLE = "%(theme)s"
+
+# Valid themes that can be substituted for %(theme)s
+VALID_THEMES = ("light", "dark")
+
 
 def validate_file_name(name: str) -> None:
     if PassthroughBackend(FileUsage.MEDIA).supports_file(name) or StaticBackend(
@@ -39,12 +46,17 @@ def validate_upload_file_name(
     if not name:
         raise ValidationError(_("File name cannot be empty"))
 
-    # Same regex is used in the frontend as well
-    if not re.match(r"^[a-zA-Z0-9._/-]+$", name):
+    # Allow %(theme)s placeholder for theme-specific files
+    # We temporarily replace it for validation, then check the result
+    name_for_validation = name.replace(THEME_VARIABLE, "theme")
+
+    # Same regex is used in the frontend as well (without %(theme)s handling there)
+    if not re.match(r"^[a-zA-Z0-9._/-]+$", name_for_validation):
         raise ValidationError(
             _(
                 "File name can only contain letters (a-z, A-Z), numbers (0-9), "
-                "dots (.), hyphens (-), underscores (_), and forward slashes (/)"
+                "dots (.), hyphens (-), underscores (_), forward slashes (/), "
+                "and the special placeholder %(theme)s for theme-specific files"
             )
         )
 

internal/web/static.go

@@ -5,6 +5,7 @@ import (
 	"encoding/hex"
 	"fmt"
 	"net/http"
+	"strings"
 	"time"
 
 	"github.com/go-http-utils/etag"
@@ -17,11 +18,44 @@ import (
 	staticWeb "goauthentik.io/web"
 )
 
+// Theme variable placeholder that can be used in file paths
+// This allows for theme-specific files like logo-%(theme)s.png
+const themeVariable = "%(theme)s"
+
+// Valid themes that can be substituted for %(theme)s
+var validThemes = []string{"light", "dark"}
+
 type StorageClaims struct {
 	jwt.RegisteredClaims
 	Path string `json:"path,omitempty"`
 }
 
+// pathMatchesWithTheme checks if the requested path matches the JWT path,
+// accounting for theme variable substitution.
+// If the JWT path contains %(theme)s, it will match the requested path
+// if substituting %(theme)s with any valid theme produces the requested path.
+func pathMatchesWithTheme(jwtPath, requestedPath string) bool {
+	// Direct match (no theme variable)
+	if jwtPath == requestedPath {
+		return true
+	}
+
+	// Check if JWT path contains theme variable
+	if !strings.Contains(jwtPath, themeVariable) {
+		return false
+	}
+
+	// Try substituting each valid theme and check for a match
+	for _, theme := range validThemes {
+		substituted := strings.ReplaceAll(jwtPath, themeVariable, theme)
+		if substituted == requestedPath {
+			return true
+		}
+	}
+
+	return false
+}
+
 func storageTokenIsValid(usage string, r *http.Request) bool {
 	tokenString := r.URL.Query().Get("token")
 	if tokenString == "" {
@@ -51,11 +85,8 @@ func storageTokenIsValid(usage string, r *http.Request) bool {
 		return false
 	}
 
-	if claims.Path != fmt.Sprintf("%s/%s", usage, r.URL.Path) {
-		return false
-	}
-
-	return true
+	requestedPath := fmt.Sprintf("%s/%s", usage, r.URL.Path)
+	return pathMatchesWithTheme(claims.Path, requestedPath)
 }
 
 func (ws *WebServer) configureStatic() {

internal/web/static_test.go

@@ -0,0 +1,95 @@
+package web
+
+import "testing"
+
+func TestPathMatchesWithTheme(t *testing.T) {
+	tests := []struct {
+		name          string
+		jwtPath       string
+		requestedPath string
+		want          bool
+	}{
+		{
+			name:          "exact match without theme variable",
+			jwtPath:       "media/public/logo.png",
+			requestedPath: "media/public/logo.png",
+			want:          true,
+		},
+		{
+			name:          "no match without theme variable",
+			jwtPath:       "media/public/logo.png",
+			requestedPath: "media/public/other.png",
+			want:          false,
+		},
+		{
+			name:          "theme variable matches light theme",
+			jwtPath:       "media/public/logo-%(theme)s.png",
+			requestedPath: "media/public/logo-light.png",
+			want:          true,
+		},
+		{
+			name:          "theme variable matches dark theme",
+			jwtPath:       "media/public/logo-%(theme)s.png",
+			requestedPath: "media/public/logo-dark.png",
+			want:          true,
+		},
+		{
+			name:          "theme variable does not match invalid theme",
+			jwtPath:       "media/public/logo-%(theme)s.png",
+			requestedPath: "media/public/logo-blue.png",
+			want:          false,
+		},
+		{
+			name:          "theme variable in directory path",
+			jwtPath:       "media/%(theme)s/logo.png",
+			requestedPath: "media/light/logo.png",
+			want:          true,
+		},
+		{
+			name:          "multiple theme variables",
+			jwtPath:       "media/%(theme)s/logo-%(theme)s.png",
+			requestedPath: "media/light/logo-light.png",
+			want:          true,
+		},
+		{
+			name:          "multiple theme variables with dark",
+			jwtPath:       "media/%(theme)s/logo-%(theme)s.png",
+			requestedPath: "media/dark/logo-dark.png",
+			want:          true,
+		},
+		{
+			name:          "multiple theme variables mixed themes should not match",
+			jwtPath:       "media/%(theme)s/logo-%(theme)s.png",
+			requestedPath: "media/light/logo-dark.png",
+			want:          false,
+		},
+		{
+			name:          "theme variable with nested path",
+			jwtPath:       "media/public/brand/logo-%(theme)s.svg",
+			requestedPath: "media/public/brand/logo-dark.svg",
+			want:          true,
+		},
+		{
+			name:          "empty paths",
+			jwtPath:       "",
+			requestedPath: "",
+			want:          true,
+		},
+		{
+			name:          "theme variable only",
+			jwtPath:       "%(theme)s",
+			requestedPath: "light",
+			want:          true,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := pathMatchesWithTheme(tt.jwtPath, tt.requestedPath)
+			if got != tt.want {
+				t.Errorf("pathMatchesWithTheme(%q, %q) = %v, want %v",
+					tt.jwtPath, tt.requestedPath, got, tt.want)
+			}
+		})
+	}
+}

web/src/admin/files/FileUploadForm.ts

@@ -14,18 +14,26 @@ import { html } from "lit";
 import { customElement, property, state } from "lit/decorators.js";
 import { createRef, ref } from "lit/directives/ref.js";
 
-// Same regex is used in the backend as well
+// Theme variable placeholder that can be used in file paths
+// This allows for theme-specific files like logo-%(theme)s.png
+const THEME_VARIABLE = "%(theme)s";
+
+// Same regex is used in the backend as well (after replacing %(theme)s)
 const VALID_FILE_NAME_PATTERN = /^[a-zA-Z0-9._/-]+$/;
 
 // Note: browsers compile `pattern` using the new `v` RegExp flag (Unicode sets). Under `/v`,
 // both `/` and `-` must be escaped inside character classes.
-const VALID_FILE_NAME_PATTERN_STRING = "^[a-zA-Z0-9._\\/\\-]+$";
+// This pattern allows %(theme)s by including %, (, and ) characters
+const VALID_FILE_NAME_PATTERN_STRING = "^[a-zA-Z0-9._\\/\\-%()+]+$";
 
 function assertValidFileName(fileName: string): void {
-    if (!VALID_FILE_NAME_PATTERN.test(fileName)) {
+    // Allow %(theme)s placeholder for theme-specific files
+    // We temporarily replace it for validation, then check the result
+    const nameForValidation = fileName.replaceAll(THEME_VARIABLE, "theme");
+    if (!VALID_FILE_NAME_PATTERN.test(nameForValidation)) {
         throw new Error(
             msg(
-                "Filename can only contain letters, numbers, dots, hyphens, underscores, and slashes",
+                "Filename can only contain letters, numbers, dots, hyphens, underscores, slashes, and the special placeholder %(theme)s",
             ),
         );
     }