OIDC + SSO

2026-07-08 20:34:25 -05:00
parent 97e9bf8f3d
commit faac5b6029
20 changed files with 1885 additions and 11 deletions
@@ -0,0 +1,489 @@
+import { importJWK, jwtVerify, type JWK, type JWTPayload } from "jose";
+import { getConfig, type Config } from "../config";
+import {
+  getOidcIdentity,
+  getOidcIdentityByEmail,
+  pruneExpiredOidcAuthStates,
+  saveOidcAuthState,
+  takeOidcAuthState,
+  upsertOidcIdentity,
+} from "../db";
+import { logger } from "../logger";
+import {
+  createExternalUser,
+  getUserById,
+  getUserByUsername,
+  updateLastLogin,
+  type User,
+  type UserRole,
+} from "../users";
+import { shouldUseSecureAuthCookie } from "./routes/auth-cookie";
+
+type OidcDiscovery = {
+  issuer: string;
+  authorization_endpoint: string;
+  token_endpoint: string;
+  jwks_uri: string;
+  userinfo_endpoint?: string;
+};
+
+type OidcClaims = JWTPayload & {
+  sub: string;
+  email?: string;
+  email_verified?: boolean;
+  preferred_username?: string;
+  name?: string;
+  groups?: unknown;
+  [key: string]: unknown;
+};
+
+const discoveryCache = new Map<string, { expiresAt: number; metadata: OidcDiscovery }>();
+const jwksCache = new Map<string, { expiresAt: number; keys: JWK[] }>();
+const DISCOVERY_TTL_MS = 60 * 60 * 1000;
+const STATE_TTL_MS = 10 * 60 * 1000;
+const OIDC_STATE_COOKIE = "overlord_oidc_state";
+
+export function getOidcPublicStatus(): { enabled: boolean; label: string; loginUrl: string | null } {
+  const oidc = getConfig().oidc;
+  const configured = Boolean(oidc.enabled && oidc.issuer && oidc.clientId);
+  return {
+    enabled: configured,
+    label: oidc.label || "Single sign-on",
+    loginUrl: configured ? "/api/oidc/login" : null,
+  };
+}
+
+export async function createOidcLoginRedirect(req: Request, url: URL): Promise<Response> {
+  const oidc = getConfig().oidc;
+  if (!isOidcConfigured(oidc)) {
+    return Response.json({ error: "OIDC is not configured" }, { status: 404 });
+  }
+
+  pruneExpiredOidcAuthStates();
+
+  const metadata = await getDiscovery(oidc);
+  const state = randomBase64Url(32);
+  const nonce = randomBase64Url(32);
+  const codeVerifier = randomBase64Url(48);
+  const codeChallenge = await pkceChallenge(codeVerifier);
+  const redirectUri = getRedirectUri(oidc, url);
+  const returnTo = normalizeReturnTo(url.searchParams.get("returnTo") || req.headers.get("Referer"));
+  const now = Date.now();
+
+  saveOidcAuthState({
+    state,
+    nonce,
+    codeVerifier,
+    returnTo,
+    createdAt: now,
+    expiresAt: now + STATE_TTL_MS,
+  });
+
+  const authUrl = new URL(metadata.authorization_endpoint);
+  authUrl.searchParams.set("response_type", "code");
+  authUrl.searchParams.set("client_id", oidc.clientId);
+  authUrl.searchParams.set("redirect_uri", redirectUri);
+  authUrl.searchParams.set("scope", normalizeScopes(oidc.scopes).join(" "));
+  authUrl.searchParams.set("state", state);
+  authUrl.searchParams.set("nonce", nonce);
+  authUrl.searchParams.set("code_challenge", codeChallenge);
+  authUrl.searchParams.set("code_challenge_method", "S256");
+
+  const headers = new Headers({ Location: authUrl.toString() });
+  headers.append("Set-Cookie", makeOidcStateCookie(state, req));
+  return new Response(null, { status: 302, headers });
+}
+
+export async function completeOidcLogin(req: Request, url: URL): Promise<{ user: User; returnTo: string }> {
+  const oidc = getConfig().oidc;
+  if (!isOidcConfigured(oidc)) {
+    throw new Error("OIDC is not configured");
+  }
+
+  const error = url.searchParams.get("error");
+  if (error) {
+    const description = url.searchParams.get("error_description");
+    throw new Error(description || error);
+  }
+
+  const code = url.searchParams.get("code") || "";
+  const state = url.searchParams.get("state") || "";
+  if (!code || !state) {
+    throw new Error("Missing OIDC callback parameters");
+  }
+
+  if (getOidcStateCookie(req) !== state) {
+    throw new Error("OIDC state cookie mismatch. Please try again.");
+  }
+
+  const savedState = takeOidcAuthState(state);
+  if (!savedState || savedState.expiresAt <= Date.now()) {
+    throw new Error("OIDC login expired. Please try again.");
+  }
+
+  const metadata = await getDiscovery(oidc);
+  const redirectUri = getRedirectUri(oidc, url);
+  const tokenSet = await exchangeCodeForTokens(oidc, metadata, {
+    code,
+    codeVerifier: savedState.codeVerifier,
+    redirectUri,
+  });
+
+  const idToken = typeof tokenSet.id_token === "string" ? tokenSet.id_token : "";
+  if (!idToken) {
+    throw new Error("OIDC provider did not return an ID token");
+  }
+
+  const claims = await verifyIdToken(oidc, metadata, idToken, savedState.nonce);
+  const mergedClaims = await maybeFetchUserinfo(metadata, tokenSet.access_token, claims);
+  const user = await resolveOidcUser(oidc, metadata.issuer, mergedClaims);
+
+  return { user, returnTo: savedState.returnTo || "/" };
+}
+
+function isOidcConfigured(oidc: Config["oidc"]): boolean {
+  return Boolean(oidc.enabled && oidc.issuer && oidc.clientId);
+}
+
+async function getDiscovery(oidc: Config["oidc"]): Promise<OidcDiscovery> {
+  const issuer = normalizeIssuerUrl(oidc.issuer);
+  const cached = discoveryCache.get(issuer);
+  if (cached && cached.expiresAt > Date.now()) return cached.metadata;
+
+  const res = await fetch(`${issuer}/.well-known/openid-configuration`, {
+    headers: { Accept: "application/json" },
+  });
+  if (!res.ok) throw new Error(`OIDC discovery failed (${res.status})`);
+
+  const metadata = await res.json() as OidcDiscovery;
+  if (!metadata.authorization_endpoint || !metadata.token_endpoint || !metadata.jwks_uri) {
+    throw new Error("OIDC discovery document is missing required endpoints");
+  }
+
+  const discoveredIssuer = normalizeIssuerUrl(metadata.issuer || "");
+  if (discoveredIssuer !== issuer) {
+    throw new Error("OIDC discovery issuer does not match the configured issuer");
+  }
+
+  const normalized = {
+    ...metadata,
+    issuer: discoveredIssuer,
+    authorization_endpoint: requireHttpsUrl(metadata.authorization_endpoint, "authorization_endpoint"),
+    token_endpoint: requireHttpsUrl(metadata.token_endpoint, "token_endpoint"),
+    jwks_uri: requireHttpsUrl(metadata.jwks_uri, "jwks_uri"),
+    userinfo_endpoint: metadata.userinfo_endpoint
+      ? requireHttpsUrl(metadata.userinfo_endpoint, "userinfo_endpoint")
+      : undefined,
+  };
+  discoveryCache.set(issuer, {
+    expiresAt: Date.now() + DISCOVERY_TTL_MS,
+    metadata: normalized,
+  });
+  return normalized;
+}
+
+async function exchangeCodeForTokens(
+  oidc: Config["oidc"],
+  metadata: OidcDiscovery,
+  input: { code: string; codeVerifier: string; redirectUri: string },
+): Promise<Record<string, any>> {
+  const body = new URLSearchParams({
+    grant_type: "authorization_code",
+    code: input.code,
+    redirect_uri: input.redirectUri,
+    client_id: oidc.clientId,
+    code_verifier: input.codeVerifier,
+  });
+
+  const headers: Record<string, string> = {
+    Accept: "application/json",
+    "Content-Type": "application/x-www-form-urlencoded",
+  };
+
+  if (oidc.clientAuthMethod === "client_secret_post" && oidc.clientSecret) {
+    body.set("client_secret", oidc.clientSecret);
+  } else if (oidc.clientAuthMethod === "client_secret_basic" && oidc.clientSecret) {
+    headers.Authorization = `Basic ${Buffer.from(`${oidc.clientId}:${oidc.clientSecret}`).toString("base64")}`;
+  }
+
+  const res = await fetch(metadata.token_endpoint, {
+    method: "POST",
+    headers,
+    body,
+  });
+  const payload = await res.json().catch(() => ({}));
+  if (!res.ok) {
+    const detail = typeof payload.error_description === "string"
+      ? payload.error_description
+      : typeof payload.error === "string"
+        ? payload.error
+        : `HTTP ${res.status}`;
+    throw new Error(`OIDC token exchange failed: ${detail}`);
+  }
+  return payload;
+}
+
+async function verifyIdToken(
+  oidc: Config["oidc"],
+  metadata: OidcDiscovery,
+  idToken: string,
+  nonce: string,
+): Promise<OidcClaims> {
+  const { payload } = await jwtVerify(idToken, async (protectedHeader) => {
+    const key = await getJwkForHeader(metadata, protectedHeader.kid, protectedHeader.alg);
+    return importJWK(key, protectedHeader.alg);
+  }, {
+    issuer: metadata.issuer,
+    audience: oidc.clientId,
+  });
+  if (payload.nonce !== nonce) {
+    throw new Error("OIDC nonce mismatch");
+  }
+  if (typeof payload.sub !== "string" || !payload.sub) {
+    throw new Error("OIDC ID token is missing subject");
+  }
+  return payload as OidcClaims;
+}
+
+async function getJwkForHeader(metadata: OidcDiscovery, kid?: string, alg?: string): Promise<JWK> {
+  const keys = await getJwks(metadata.jwks_uri);
+  const key = keys.find((candidate) =>
+    (!kid || candidate.kid === kid) &&
+    (!alg || !candidate.alg || candidate.alg === alg) &&
+    (!candidate.use || candidate.use === "sig"),
+  );
+  if (!key) {
+    throw new Error("OIDC signing key was not found in JWKS");
+  }
+  return key;
+}
+
+async function getJwks(jwksUri: string): Promise<JWK[]> {
+  const cached = jwksCache.get(jwksUri);
+  if (cached && cached.expiresAt > Date.now()) return cached.keys;
+
+  const res = await fetch(jwksUri, { headers: { Accept: "application/json" } });
+  if (!res.ok) throw new Error(`OIDC JWKS request failed (${res.status})`);
+  const body = await res.json() as { keys?: JWK[] };
+  const keys = Array.isArray(body.keys) ? body.keys : [];
+  if (!keys.length) throw new Error("OIDC JWKS did not contain signing keys");
+  jwksCache.set(jwksUri, { expiresAt: Date.now() + 10 * 60 * 1000, keys });
+  return keys;
+}
+
+async function maybeFetchUserinfo(
+  metadata: OidcDiscovery,
+  accessToken: unknown,
+  claims: OidcClaims,
+): Promise<OidcClaims> {
+  if (!metadata.userinfo_endpoint || typeof accessToken !== "string" || !accessToken) {
+    return claims;
+  }
+  try {
+    const res = await fetch(metadata.userinfo_endpoint, {
+      headers: { Accept: "application/json", Authorization: `Bearer ${accessToken}` },
+    });
+    if (!res.ok) return claims;
+    const userinfo = await res.json();
+    return { ...claims, ...userinfo, sub: claims.sub };
+  } catch (err) {
+    logger.warn("[oidc] userinfo request failed", err);
+    return claims;
+  }
+}
+
+export async function resolveOidcUser(oidc: Config["oidc"], issuer: string, claims: OidcClaims): Promise<User> {
+  const email = typeof claims.email === "string" ? claims.email.trim().toLowerCase() : "";
+  const usernameClaim = typeof claims.preferred_username === "string"
+    ? claims.preferred_username
+    : typeof claims.name === "string"
+      ? claims.name
+      : "";
+
+  enforceAllowedIdentity(oidc, email);
+
+  const existingIdentity = getOidcIdentity(issuer, claims.sub);
+  if (existingIdentity) {
+    const existingUser = getUserById(existingIdentity.userId);
+    if (existingUser) {
+      updateLastLogin(existingUser.id);
+      upsertOidcIdentity({
+        issuer,
+        subject: claims.sub,
+        userId: existingUser.id,
+        email,
+        username: usernameClaim,
+      });
+      return existingUser;
+    }
+  }
+
+  if (oidc.allowEmailLink && email && claims.email_verified === true) {
+    const existingEmailIdentity = getOidcIdentityByEmail(issuer, email);
+    if (existingEmailIdentity) {
+      const user = getUserById(existingEmailIdentity.userId);
+      if (user) {
+        updateLastLogin(user.id);
+        upsertOidcIdentity({ issuer, subject: claims.sub, userId: user.id, email, username: usernameClaim });
+        return user;
+      }
+    }
+  }
+
+  if (!oidc.autoProvision) {
+    throw new Error("No linked Overlord account exists for this OIDC identity");
+  }
+
+  const username = pickAvailableUsername(usernameClaim || email.split("@")[0] || `oidc_${claims.sub.slice(0, 12)}`);
+  const role = roleFromClaims(oidc, claims);
+  const created = await createExternalUser(username, role, "oidc", "oidc");
+  if (!created.success || !created.userId) {
+    throw new Error(created.error || "Failed to provision OIDC user");
+  }
+
+  upsertOidcIdentity({ issuer, subject: claims.sub, userId: created.userId, email, username: usernameClaim });
+  updateLastLogin(created.userId);
+  const user = getUserById(created.userId);
+  if (!user) throw new Error("Provisioned user could not be loaded");
+  return user;
+}
+
+function enforceAllowedIdentity(oidc: Config["oidc"], email: string): void {
+  const allowedEmails = oidc.allowedEmails.map((v) => v.toLowerCase());
+  const allowedDomains = oidc.allowedDomains.map((v) => v.toLowerCase().replace(/^@/, ""));
+
+  if (allowedEmails.length > 0 && (!email || !allowedEmails.includes(email))) {
+    throw new Error("This OIDC account is not allowed to access Overlord");
+  }
+
+  if (allowedDomains.length > 0) {
+    const domain = email.includes("@") ? email.split("@").pop()!.toLowerCase() : "";
+    if (!domain || !allowedDomains.includes(domain)) {
+      throw new Error("This OIDC email domain is not allowed to access Overlord");
+    }
+  }
+}
+
+function roleFromClaims(oidc: Config["oidc"], claims: OidcClaims): UserRole {
+  const groups = getClaimStrings(claims[oidc.groupClaim || "groups"]);
+  const hasGroup = (configured: string[]) => configured.some((group) => groups.has(group));
+  if (hasGroup(oidc.adminGroups)) return "admin";
+  if (hasGroup(oidc.operatorGroups)) return "operator";
+  if (hasGroup(oidc.viewerGroups)) return "viewer";
+  return oidc.defaultRole;
+}
+
+function getClaimStrings(value: unknown): Set<string> {
+  if (Array.isArray(value)) return new Set(value.map((v) => String(v)));
+  if (typeof value === "string" && value.trim()) return new Set([value.trim()]);
+  return new Set();
+}
+
+function pickAvailableUsername(seed: string): string {
+  const base = sanitizeUsername(seed) || "oidc_user";
+  if (!getUserByUsername(base)) return base;
+  const trimmed = base.slice(0, 27);
+  for (let i = 1; i < 1000; i++) {
+    const candidate = `${trimmed}_${i}`;
+    if (!getUserByUsername(candidate)) return candidate;
+  }
+  return `oidc_${randomBase64Url(8)}`.slice(0, 32);
+}
+
+function sanitizeUsername(value: string): string {
+  const cleaned = value
+    .toLowerCase()
+    .replace(/[^a-z0-9_-]+/g, "_")
+    .replace(/^_+|_+$/g, "")
+    .slice(0, 32);
+  return cleaned.length >= 3 ? cleaned : "";
+}
+
+function normalizeScopes(scopes: string[]): string[] {
+  const result = Array.from(new Set(["openid", ...scopes.map((s) => String(s).trim()).filter(Boolean)]));
+  return result;
+}
+
+function getRedirectUri(oidc: Config["oidc"], url: URL): string {
+  return oidc.redirectUri || new URL("/api/oidc/callback", url.origin).toString();
+}
+
+export function makeOidcStateCookie(state: string, req: Request): string {
+  const securePart = shouldUseSecureAuthCookie(req) ? "Secure; " : "";
+  return `${OIDC_STATE_COOKIE}=${state}; HttpOnly; ${securePart}SameSite=Lax; Path=/api/oidc/callback; Max-Age=${Math.ceil(STATE_TTL_MS / 1000)}`;
+}
+
+export function makeOidcStateCookieClear(req: Request): string {
+  const securePart = shouldUseSecureAuthCookie(req) ? "Secure; " : "";
+  return `${OIDC_STATE_COOKIE}=; HttpOnly; ${securePart}SameSite=Lax; Path=/api/oidc/callback; Max-Age=0`;
+}
+
+function getOidcStateCookie(req: Request): string | null {
+  const cookieHeader = req.headers.get("Cookie");
+  if (!cookieHeader) return null;
+
+  const cookies = cookieHeader.split(/;\s*/);
+  for (const cookie of cookies) {
+    const [name, ...valueParts] = cookie.split("=");
+    if (name === OIDC_STATE_COOKIE) {
+      return valueParts.join("=") || null;
+    }
+  }
+  return null;
+}
+
+function normalizeIssuerUrl(value: string): string {
+  let parsed: URL;
+  try {
+    parsed = new URL(value);
+  } catch {
+    throw new Error("OIDC issuer must be a valid HTTPS URL");
+  }
+  if (parsed.protocol !== "https:") {
+    throw new Error("OIDC issuer must use HTTPS");
+  }
+  if (parsed.username || parsed.password) {
+    throw new Error("OIDC issuer must not include credentials");
+  }
+  return parsed.toString().replace(/\/+$/, "");
+}
+
+function requireHttpsUrl(value: string, field: string): string {
+  let parsed: URL;
+  try {
+    parsed = new URL(value);
+  } catch {
+    throw new Error(`OIDC ${field} must be a valid HTTPS URL`);
+  }
+  if (parsed.protocol !== "https:") {
+    throw new Error(`OIDC ${field} must use HTTPS`);
+  }
+  if (parsed.username || parsed.password) {
+    throw new Error(`OIDC ${field} must not include credentials`);
+  }
+  return parsed.toString();
+}
+
+function normalizeReturnTo(value: string | null): string | null {
+  if (!value) return null;
+  try {
+    const url = new URL(value, "https://placeholder.local");
+    const relative = `${url.pathname}${url.search}${url.hash}`;
+    if (!relative.startsWith("/") || relative.startsWith("//")) return null;
+    if (relative.startsWith("/api/")) return null;
+    return relative;
+  } catch {
+    return null;
+  }
+}
+
+function randomBase64Url(bytes: number): string {
+  const buf = new Uint8Array(bytes);
+  crypto.getRandomValues(buf);
+  return Buffer.from(buf).toString("base64url");
+}
+
+async function pkceChallenge(verifier: string): Promise<string> {
+  const digest = await crypto.subtle.digest("SHA-256", new TextEncoder().encode(verifier));
+  return Buffer.from(digest).toString("base64url");
+}
@@ -8,6 +8,7 @@ import {
  revokeToken,
 } from "../../auth";
 import { AuditAction, logAudit } from "../../auditLog";
+import { getConfig } from "../../config";
 import { buildTotpUri, generateMfaSecret, verifyTotpCode } from "../../mfa";
 import { createQrSvg } from "../../qr";
 import {
@@ -50,6 +51,10 @@ export async function handleAuthRoutes(
  url: URL,
  server: RequestIpProvider,
 ): Promise<Response | null> {
+  if (req.method === "GET" && url.pathname === "/api/login/branding") {
+    return Response.json(getConfig().appearance.loginBranding);
+  }
+
  if (req.method === "POST" && url.pathname === "/api/login") {
    const ip = server.requestIP(req)?.address || "unknown";

@@ -1,7 +1,7 @@
 import { authenticateRequest } from "../../auth";
 import { AuditAction, getAuditLogs, logAudit } from "../../auditLog";
 import { logger } from "../../logger";
-import { getConfig, updateSecurityConfig, updateTlsConfig, updateAppearanceConfig, updateChatConfig, getExportableConfig, importFullConfig, updateRegistrationConfig, updateBuildRateLimitConfig, updateThumbnailsConfig, updateInputArchiveConfig } from "../../config";
+import { getConfig, updateSecurityConfig, updateTlsConfig, updateOidcConfig, updateAppearanceConfig, updateChatConfig, getExportableConfig, importFullConfig, updateRegistrationConfig, updateBuildRateLimitConfig, updateThumbnailsConfig, updateInputArchiveConfig } from "../../config";
 import {
  getClientMetricsSummary,
  getClientMetricsSummaryForUser,
@@ -39,6 +39,15 @@ type MiscRouteDeps = {
  tlsSource?: "certbot" | "configured" | "self-signed";
 };

+function maskOidcSettings() {
+  const oidc = getConfig().oidc;
+  return {
+    ...oidc,
+    clientSecret: "",
+    clientSecretSet: Boolean(oidc.clientSecret),
+  };
+}
+
 function clampProfileDuration(value: unknown): number {
  const parsed = Number(value);
  if (!Number.isFinite(parsed)) return 5000;
@@ -686,6 +695,63 @@ export async function handleMiscRoutes(
    }
  }

+  if (url.pathname === "/api/settings/oidc") {
+    const user = await authenticateRequest(req);
+    if (!user) {
+      return new Response("Unauthorized", { status: 401 });
+    }
+    try {
+      requirePermission(user, "system:oidc");
+    } catch (error) {
+      if (error instanceof Response) return error;
+      return new Response("Forbidden", { status: 403 });
+    }
+
+    if (req.method === "GET") {
+      return Response.json({ oidc: maskOidcSettings() }, { headers: deps.CORS_HEADERS });
+    }
+
+    if (req.method === "PUT") {
+      let body: any = {};
+      try {
+        body = await req.json();
+      } catch {
+        return Response.json({ error: "Invalid JSON" }, { status: 400 });
+      }
+
+      const updated = await updateOidcConfig({
+        enabled: Boolean(body?.enabled),
+        label: typeof body?.label === "string" ? body.label : undefined,
+        issuer: typeof body?.issuer === "string" ? body.issuer : undefined,
+        clientId: typeof body?.clientId === "string" ? body.clientId : undefined,
+        clientSecret: typeof body?.clientSecret === "string" && body.clientSecret.length > 0 ? body.clientSecret : undefined,
+        redirectUri: typeof body?.redirectUri === "string" ? body.redirectUri : undefined,
+        scopes: body?.scopes,
+        clientAuthMethod: body?.clientAuthMethod,
+        autoProvision: Boolean(body?.autoProvision),
+        allowEmailLink: Boolean(body?.allowEmailLink),
+        defaultRole: body?.defaultRole,
+        allowedEmails: body?.allowedEmails,
+        allowedDomains: body?.allowedDomains,
+        groupClaim: typeof body?.groupClaim === "string" ? body.groupClaim : undefined,
+        adminGroups: body?.adminGroups,
+        operatorGroups: body?.operatorGroups,
+        viewerGroups: body?.viewerGroups,
+      });
+
+      logAudit({
+        timestamp: Date.now(),
+        username: user.username,
+        ip: deps.requestIP?.(req)?.address || "unknown",
+        action: AuditAction.COMMAND,
+        details: `Updated OIDC settings (enabled=${updated.enabled})`,
+        success: true,
+      });
+
+      return Response.json({ ok: true, oidc: maskOidcSettings() }, { headers: deps.CORS_HEADERS });
+    }
+  }
+
  if (req.method === "POST" && url.pathname === "/api/settings/tls/certbot/setup") {
    const user = await authenticateRequest(req);
    if (!user) {
@@ -1135,8 +1201,12 @@ export async function handleMiscRoutes(
    }

    if (req.method === "GET") {
+      const appearance = getConfig().appearance;
      return Response.json(
-        { customCSS: getConfig().appearance?.customCSS || "" },
+        {
+          customCSS: appearance?.customCSS || "",
+          loginBranding: appearance.loginBranding,
+        },
        { headers: deps.CORS_HEADERS },
      );
    }
@@ -1153,8 +1223,12 @@ export async function handleMiscRoutes(
      if (customCSS.length > 51200) {
        return Response.json({ error: "CSS exceeds 50 KB limit" }, { status: 400 });
      }
+      const loginBranding =
+        body?.loginBranding && typeof body.loginBranding === "object"
+          ? body.loginBranding
+          : undefined;

-      const updated = await updateAppearanceConfig(customCSS);
+      const updated = await updateAppearanceConfig(customCSS, loginBranding);

      logAudit({
        timestamp: Date.now(),
@@ -1165,7 +1239,10 @@ export async function handleMiscRoutes(
        success: true,
      });

-      return Response.json({ ok: true, customCSS: updated.customCSS }, { headers: deps.CORS_HEADERS });
+      return Response.json(
+        { ok: true, customCSS: updated.customCSS, loginBranding: updated.loginBranding },
+        { headers: deps.CORS_HEADERS },
+      );
    }
  }

@@ -0,0 +1,177 @@
+import { afterAll, beforeAll, describe, expect, test } from "bun:test";
+import { getConfig, updateOidcConfig, updateSecurityConfig, type Config } from "../../config";
+import { createUser } from "../../users";
+import { createOidcLoginRedirect, resolveOidcUser } from "../oidc";
+import { getOidcLocalMfaBlockReason, handleOidcRoutes } from "./oidc-routes";
+
+const server = {
+  requestIP: () => ({ address: "127.0.0.1" }),
+};
+
+let originalOidc: Config["oidc"];
+let originalSecurity: Config["security"];
+const originalFetch = globalThis.fetch;
+
+beforeAll(() => {
+  originalOidc = { ...getConfig().oidc, scopes: [...getConfig().oidc.scopes] };
+  originalSecurity = { ...getConfig().security };
+});
+
+afterAll(async () => {
+  globalThis.fetch = originalFetch;
+  await updateOidcConfig(originalOidc);
+  await updateSecurityConfig(originalSecurity);
+});
+
+describe("OIDC routes", () => {
+  test("status reports disabled when OIDC is not configured", async () => {
+    const req = new Request("https://localhost/api/oidc/status");
+    const url = new URL(req.url);
+
+    const res = await handleOidcRoutes(req, url, server);
+
+    expect(res?.status).toBe(200);
+    const body = await res!.json();
+    expect(body.enabled).toBe(false);
+    expect(body.loginUrl).toBeNull();
+  });
+
+  test("login redirect stores a browser-bound OIDC state cookie", async () => {
+    const issuer = `https://oidc-state-${Date.now()}.example.test`;
+    await configureOidc(issuer);
+    mockDiscovery(issuer);
+
+    const req = new Request("https://localhost/api/oidc/login?returnTo=/settings.html");
+    const res = await createOidcLoginRedirect(req, new URL(req.url));
+
+    expect(res.status).toBe(302);
+    expect(res.headers.get("Set-Cookie")).toContain("overlord_oidc_state=");
+    expect(res.headers.get("Set-Cookie")).toContain("HttpOnly");
+    expect(res.headers.get("Set-Cookie")).toContain("SameSite=Lax");
+
+    const redirect = new URL(res.headers.get("Location")!);
+    expect(redirect.searchParams.get("state")).toBeTruthy();
+    expect(redirect.searchParams.get("code_challenge_method")).toBe("S256");
+  });
+
+  test("callback rejects state values that are not bound to the browser cookie", async () => {
+    const issuer = `https://oidc-csrf-${Date.now()}.example.test`;
+    await configureOidc(issuer);
+    mockDiscovery(issuer);
+
+    const loginReq = new Request("https://localhost/api/oidc/login");
+    const loginRes = await createOidcLoginRedirect(loginReq, new URL(loginReq.url));
+    const state = new URL(loginRes.headers.get("Location")!).searchParams.get("state")!;
+
+    const callbackReq = new Request(`https://localhost/api/oidc/callback?code=fake-code&state=${state}`);
+    const callbackRes = await handleOidcRoutes(callbackReq, new URL(callbackReq.url), server);
+
+    expect(callbackRes?.status).toBe(302);
+    const location = new URL(callbackRes!.headers.get("Location")!);
+    expect(location.pathname).toBe("/login.html");
+    expect(location.searchParams.get("oidc_error")).toContain("state cookie mismatch");
+    expect(callbackRes!.headers.get("Set-Cookie")).toContain("overlord_oidc_state=;");
+  });
+
+  test("login redirect rejects non-HTTPS issuers before discovery", async () => {
+    await configureOidc("http://oidc-insecure.example.test");
+    setMockFetch(async () => {
+      throw new Error("fetch should not be called for insecure issuer");
+    });
+
+    const req = new Request("https://localhost/api/oidc/login");
+    await expect(createOidcLoginRedirect(req, new URL(req.url))).rejects.toThrow("HTTPS");
+  });
+
+  test("email linking does not fall back to local usernames", async () => {
+    const username = `oidc_link_${Date.now().toString(36)}`;
+    const created = await createUser(username, "Aa1!VeryLongTestPassword_2026", "operator", "test");
+    expect(created.success).toBe(true);
+
+    const oidc: Config["oidc"] = {
+      ...getConfig().oidc,
+      enabled: true,
+      issuer: "https://issuer.example.test",
+      clientId: "client",
+      allowEmailLink: true,
+      autoProvision: false,
+      allowedEmails: [],
+      allowedDomains: [],
+    };
+
+    await expect(resolveOidcUser(oidc, "https://issuer.example.test", {
+      sub: `subject-${Date.now()}`,
+      email: `${username}@example.test`,
+      email_verified: true,
+      preferred_username: "not-local",
+    } as any)).rejects.toThrow("No linked Overlord account exists");
+  });
+
+  test("OIDC session issuance is blocked when local MFA is enabled or required", async () => {
+    await updateSecurityConfig({
+      ...getConfig().security,
+      mfaRequiredForAdmins: true,
+      mfaRequiredForNonAdmins: false,
+    });
+
+    expect(getOidcLocalMfaBlockReason({
+      role: "operator",
+      mfa_enabled: 1,
+      mfa_secret: "secret",
+    })).toContain("Local MFA is enabled");
+
+    expect(getOidcLocalMfaBlockReason({
+      role: "admin",
+      mfa_enabled: 0,
+      mfa_secret: null,
+    })).toContain("Local MFA is required");
+
+    expect(getOidcLocalMfaBlockReason({
+      role: "operator",
+      mfa_enabled: 0,
+      mfa_secret: null,
+    })).toBeNull();
+  });
+});
+
+async function configureOidc(issuer: string): Promise<void> {
+  await updateOidcConfig({
+    enabled: true,
+    issuer,
+    clientId: "overlord-test",
+    clientSecret: "secret",
+    redirectUri: "https://localhost/api/oidc/callback",
+    scopes: ["openid", "profile", "email"],
+    clientAuthMethod: "client_secret_post",
+    autoProvision: false,
+    allowEmailLink: false,
+    defaultRole: "viewer",
+    allowedEmails: [],
+    allowedDomains: [],
+    groupClaim: "groups",
+    adminGroups: [],
+    operatorGroups: [],
+    viewerGroups: [],
+  });
+}
+
+function mockDiscovery(issuer: string): void {
+  setMockFetch(async (input: RequestInfo | URL) => {
+    const url = String(input);
+    if (url === `${issuer}/.well-known/openid-configuration`) {
+      return Response.json({
+        issuer,
+        authorization_endpoint: `${issuer}/authorize`,
+        token_endpoint: `${issuer}/token`,
+        jwks_uri: `${issuer}/jwks`,
+      });
+    }
+    throw new Error(`Unexpected OIDC fetch: ${url}`);
+  });
+}
+
+function setMockFetch(handler: (input: RequestInfo | URL, init?: RequestInit) => Promise<Response>): void {
+  globalThis.fetch = Object.assign(handler, {
+    preconnect: originalFetch.preconnect,
+  }) as typeof fetch;
+}
@@ -0,0 +1,98 @@
+import { generateToken, getSessionTtlSeconds } from "../../auth";
+import { AuditAction, logAudit } from "../../auditLog";
+import { logger } from "../../logger";
+import { isMfaRequiredForUser, type User } from "../../users";
+import {
+  completeOidcLogin,
+  createOidcLoginRedirect,
+  getOidcPublicStatus,
+  makeOidcStateCookieClear,
+} from "../oidc";
+import { makeAuthCookie } from "./auth-cookie";
+
+type RequestIpProvider = {
+  requestIP: (req: Request) => { address?: string } | null | undefined;
+};
+
+export async function handleOidcRoutes(
+  req: Request,
+  url: URL,
+  server: RequestIpProvider,
+): Promise<Response | null> {
+  if (req.method === "GET" && url.pathname === "/api/oidc/status") {
+    return Response.json(getOidcPublicStatus());
+  }
+
+  if (req.method === "GET" && url.pathname === "/api/oidc/login") {
+    try {
+      return await createOidcLoginRedirect(req, url);
+    } catch (error) {
+      logger.error("[oidc] login redirect failed", error);
+      return redirectToLoginError(url, "OIDC login is not available");
+    }
+  }
+
+  if (req.method === "GET" && url.pathname === "/api/oidc/callback") {
+    const ip = server.requestIP(req)?.address || "unknown";
+    try {
+      const { user, returnTo } = await completeOidcLogin(req, url);
+      const mfaBlockReason = getOidcLocalMfaBlockReason(user);
+      if (mfaBlockReason) throw new Error(mfaBlockReason);
+
+      const userAgent = req.headers.get("User-Agent") || null;
+      const token = await generateToken(user, { ip, userAgent: userAgent || undefined });
+      const headers = new Headers({
+        "Location": new URL(returnTo, url.origin).toString(),
+      });
+      headers.append("Set-Cookie", makeAuthCookie(token, getSessionTtlSeconds(), req));
+      headers.append("Set-Cookie", makeOidcStateCookieClear(req));
+
+      logAudit({
+        timestamp: Date.now(),
+        username: user.username,
+        ip,
+        action: AuditAction.LOGIN,
+        success: true,
+        details: "OIDC login",
+      });
+
+      return new Response(null, {
+        status: 302,
+        headers,
+      });
+    } catch (error) {
+      logger.warn("[oidc] callback failed", error);
+      logAudit({
+        timestamp: Date.now(),
+        username: "unknown",
+        ip,
+        action: AuditAction.LOGIN_FAILED,
+        success: false,
+        errorMessage: error instanceof Error ? error.message : String(error),
+      });
+      return redirectToLoginError(url, error instanceof Error ? error.message : "OIDC login failed", req);
+    }
+  }
+
+  return null;
+}
+
+export function getOidcLocalMfaBlockReason(
+  user: Pick<User, "role" | "mfa_enabled" | "mfa_secret">,
+): string | null {
+  if (user.mfa_enabled && user.mfa_secret) {
+    return "Local MFA is enabled for this account. Use password login to complete MFA.";
+  }
+  if (isMfaRequiredForUser(user)) {
+    return "Local MFA is required for this account and cannot be completed through OIDC.";
+  }
+  return null;
+}
+
+function redirectToLoginError(url: URL, message: string, req?: Request): Response {
+  const loginUrl = new URL("/login.html", url.origin);
+  loginUrl.searchParams.set("oidc_error", message);
+  const headers = new Headers({ Location: loginUrl.toString() });
+  if (req) headers.append("Set-Cookie", makeOidcStateCookieClear(req));
+  return new Response(null, { status: 302, headers });
+}