feat: per-domain branding overrides on /api/config, manifest, pwa-icon #332

lib/admin/domain-branding.ts

@@ -0,0 +1,144 @@
+/**
+ * Per-domain branding overrides: schema, parsing, host extraction, and match.
+ *
+ * The webmail can be served on multiple hostnames (e.g. mail1.example.com,
+ * mail2.other.com). Each hostname can override a subset of branding fields;
+ * unset fields fall back to the global admin/env/default value.
+ */
+
+import type { NextRequest } from 'next/server';
+
+/** Config keys that can be overridden per domain. */
+export const BRANDING_OVERRIDE_KEYS = [
+  'appName',
+  'appShortName',
+  'appDescription',
+  'faviconUrl',
+  'pwaIconUrl',
+  'pwaThemeColor',
+  'pwaBackgroundColor',
+  'appLogoLightUrl',
+  'appLogoDarkUrl',
+  'loginLogoLightUrl',
+  'loginLogoDarkUrl',
+  'loginCompanyName',
+  'loginImprintUrl',
+  'loginPrivacyPolicyUrl',
+  'loginWebsiteUrl',
+] as const;
+
+export type BrandingOverrideKey = (typeof BRANDING_OVERRIDE_KEYS)[number];
+
+export interface DomainBrandingEntry {
+  /**
+   * Hostname this entry applies to. Either an exact host like
+   * "mail.example.com" or a wildcard like "*.example.com" (matches any
+   * direct or deeper subdomain). Case-insensitive; trailing dots are
+   * stripped on parse.
+   */
+  host: string;
+  appName?: string;
+  appShortName?: string;
+  appDescription?: string;
+  faviconUrl?: string;
+  pwaIconUrl?: string;
+  pwaThemeColor?: string;
+  pwaBackgroundColor?: string;
+  appLogoLightUrl?: string;
+  appLogoDarkUrl?: string;
+  loginLogoLightUrl?: string;
+  loginLogoDarkUrl?: string;
+  loginCompanyName?: string;
+  loginImprintUrl?: string;
+  loginPrivacyPolicyUrl?: string;
+  loginWebsiteUrl?: string;
+}
+
+// Accepts plain hostnames (foo, foo.bar, foo.bar.baz) and one-level wildcards
+// at the leftmost label (*.example.com). Rejects IPs, scheme/path/userinfo,
+// and embedded wildcards.
+const HOST_RE = /^(\*\.)?[a-z0-9]([a-z0-9-]*[a-z0-9])?(\.[a-z0-9]([a-z0-9-]*[a-z0-9])?)*$/;
+
+function normalizeHost(host: string): string {
+  return host.trim().toLowerCase().replace(/\.+$/, '');
+}
+
+/** Parse the raw config value (array of entries, or string-JSON). Invalid entries are dropped. */
+export function parseDomainBranding(raw: unknown): DomainBrandingEntry[] {
+  if (!raw) return [];
+  let value = raw;
+  if (typeof value === 'string') {
+    if (!value.trim()) return [];
+    try {
+      value = JSON.parse(value);
+    } catch {
+      return [];
+    }
+  }
+  if (!Array.isArray(value)) return [];
+
+  const seen = new Set<string>();
+  const out: DomainBrandingEntry[] = [];
+  for (const item of value) {
+    if (!item || typeof item !== 'object') continue;
+    const rec = item as Record<string, unknown>;
+    const rawHost = typeof rec.host === 'string' ? rec.host : '';
+    const host = normalizeHost(rawHost);
+    if (!host || !HOST_RE.test(host)) continue;
+    if (seen.has(host)) continue;
+    seen.add(host);
+
+    const entry: DomainBrandingEntry = { host };
+    const writable = entry as unknown as Record<string, string>;
+    for (const key of BRANDING_OVERRIDE_KEYS) {
+      const v = rec[key];
+      if (typeof v === 'string' && v.length > 0) {
+        writable[key] = v;
+      }
+    }
+    out.push(entry);
+  }
+  return out;
+}
+
+type HeadersLike = Headers | { get(name: string): string | null };
+
+/**
+ * Pick the request's host, preferring X-Forwarded-Host (first entry if
+ * comma-separated) over Host. Strips the port. Returns null when no usable
+ * host header is set.
+ */
+export function pickRequestHost(headersOrReq: NextRequest | HeadersLike): string | null {
+  const headers: HeadersLike = 'headers' in headersOrReq ? (headersOrReq as NextRequest).headers : headersOrReq;
+  const raw = headers.get('x-forwarded-host') || headers.get('host');
+  if (!raw) return null;
+  const first = raw.split(',')[0]?.trim();
+  if (!first) return null;
+  return normalizeHost(first.split(':')[0]);
+}
+
+/**
+ * Find the entry whose host matches `host`. Exact match always wins; among
+ * wildcards the longest (most-specific) suffix wins. Returns {} when no
+ * entry matches.
+ */
+export function matchDomainBranding(
+  host: string | null,
+  entries: DomainBrandingEntry[],
+): Partial<DomainBrandingEntry> {
+  if (!host || entries.length === 0) return {};
+  const lower = normalizeHost(host);
+  let wildcardMatch: DomainBrandingEntry | undefined;
+  for (const entry of entries) {
+    if (entry.host === lower) return entry;
+    if (entry.host.startsWith('*.')) {
+      const suffix = entry.host.slice(1); // ".example.com"
+      if (lower.endsWith(suffix) && lower.length > suffix.length) {
+        if (!wildcardMatch || entry.host.length > wildcardMatch.host.length) {
+          wildcardMatch = entry;
+        }
+      }
+    }
+  }
+  return wildcardMatch ?? {};
+}

lib/admin/types.ts

@@ -163,6 +163,7 @@ export const CONFIG_ENV_MAP: Record<string, { envVar: string; fileEnvVar?: strin
   allowCustomJmapEndpoint: { envVar: 'ALLOW_CUSTOM_JMAP_ENDPOINT', type: 'boolean', defaultValue: false },
   jmapServers: { envVar: 'JMAP_SERVERS', type: 'json', defaultValue: [] },
   jmapServerAutoPickByDomain: { envVar: 'JMAP_SERVER_AUTO_PICK_BY_DOMAIN', type: 'boolean', defaultValue: false },
+  domainBranding: { envVar: 'DOMAIN_BRANDING', type: 'json', defaultValue: [] },
   autoSsoEnabled: { envVar: 'AUTO_SSO_ENABLED', type: 'boolean', defaultValue: false },
   cookieSameSite: { envVar: 'COOKIE_SAME_SITE', type: 'enum', defaultValue: 'lax', enumValues: ['lax', 'strict', 'none'] },
   allowedFrameAncestors: { envVar: 'ALLOWED_FRAME_ANCESTORS', type: 'string', defaultValue: '' },