Merge pull request #107 from aakhter/cod-29-network-auth-downloads

fix: COD-29 harden network auth and downloads

src/web/middleware/auth.ts

@@ -8,7 +8,7 @@
  * - CORS (localhost only)
  */
 
-import { FastifyInstance } from 'fastify';
+import type { FastifyInstance, FastifyReply } from 'fastify';
 import { randomBytes, timingSafeEqual } from 'node:crypto';
 import { StaleExpirationMap } from '../../utils/index.js';
 import type { AuthSessionRecord } from '../ports/auth-port.js';
@@ -69,6 +69,13 @@ export function registerAuthMiddleware(app: FastifyInstance, https: boolean): Au
   const authSessions = state.authSessions;
   const authFailures = state.authFailures;
 
+  function sendAuthRateLimit(reply: FastifyReply, clientIp: string): void {
+    const remainingMs = authFailures.getRemainingTtl(clientIp) ?? AUTH_FAILURE_WINDOW_MS;
+    const retryAfterSeconds = Math.max(1, Math.ceil(remainingMs / 1000));
+    reply.header('Retry-After', String(retryAfterSeconds));
+    reply.code(429).send('Too Many Requests — try again later');
+  }
+
   app.addHook('onRequest', (req, reply, done) => {
     // Hook events come from local Claude Code hooks (curl from localhost) — no auth headers available.
     // Safe: validated by HookEventSchema, only triggers broadcasts.
@@ -90,13 +97,6 @@ export function registerAuthMiddleware(app: FastifyInstance, https: boolean): Au
 
     const clientIp = req.ip;
 
-    // Rate limit: reject if too many failed attempts from this IP
-    const failures = authFailures.get(clientIp) ?? 0;
-    if (failures >= AUTH_FAILURE_MAX) {
-      reply.code(429).send('Too Many Requests — try again later');
-      return;
-    }
-
     // Check session cookie first (avoids re-sending credentials on every request)
     // Use get() instead of has() so refreshOnGet extends the TTL on active sessions
     const sessionToken = req.cookies[AUTH_COOKIE_NAME];
@@ -140,6 +140,13 @@ export function registerAuthMiddleware(app: FastifyInstance, https: boolean): Au
       return;
     }
 
+    // Rate limit only requests that failed to authenticate on this attempt.
+    const failures = authFailures.get(clientIp) ?? 0;
+    if (failures >= AUTH_FAILURE_MAX) {
+      sendAuthRateLimit(reply, clientIp);
+      return;
+    }
+
     // Auth failed — track failure count
     authFailures.set(clientIp, failures + 1);
 

src/web/network-auth-policy.ts

@@ -0,0 +1,21 @@
+import { isIP } from 'node:net';
+
+const EXPLICIT_TRUE_VALUES = new Set(['1', 'true', 'yes', 'on']);
+
+export function isExplicitlyEnabled(value: string | undefined): boolean {
+  return value !== undefined && EXPLICIT_TRUE_VALUES.has(value.trim().toLowerCase());
+}
+
+export function isLoopbackBindHost(host: string): boolean {
+  const normalized = host
+    .trim()
+    .toLowerCase()
+    .replace(/^\[(.*)\]$/, '$1');
+  if (normalized === 'localhost' || normalized === '::1' || normalized === '0:0:0:0:0:0:0:1') {
+    return true;
+  }
+  if (isIP(normalized) === 4 && normalized.startsWith('127.')) {
+    return true;
+  }
+  return normalized.startsWith('::ffff:127.');
+}

src/web/routes/file-routes.ts

@@ -4,7 +4,8 @@
  */
 
 import { FastifyInstance } from 'fastify';
-import { join } from 'node:path';
+import { basename as pathBasename, join } from 'node:path';
+import { homedir } from 'node:os';
 import fs from 'node:fs/promises';
 import { ApiErrorCode, createErrorResponse, getErrorMessage } from '../../types.js';
 import { fileStreamManager } from '../../file-stream-manager.js';
@@ -278,7 +279,6 @@ export function registerFileRoutes(app: FastifyInstance, ctx: SessionPort): void
         jpeg: 'image/jpeg',
         gif: 'image/gif',
         webp: 'image/webp',
-        svg: 'image/svg+xml',
         ico: 'image/x-icon',
         bmp: 'image/bmp',
         mp4: 'video/mp4',
@@ -292,19 +292,21 @@ export function registerFileRoutes(app: FastifyInstance, ctx: SessionPort): void
       };
 
       const content = await fs.readFile(resolvedPath);
-      if (download === 'true') {
-        const rawBasename = filePath!.split('/').pop() || 'download';
-        // Sanitize filename for Content-Disposition header (prevent header injection)
-        const basename = rawBasename.replace(/["\\\r\n]/g, '_');
+      const rawBasename = filePath!.split('/').pop() || 'download';
+      // Sanitize filename for Content-Disposition header (prevent header injection)
+      const basename = rawBasename.replace(/["\\\r\n]/g, '_');
+      if (download === 'true' || ext === 'svg') {
         reply.raw.writeHead(200, {
-          'Content-Type': mimeTypes[ext] || 'application/octet-stream',
+          'Content-Type': ext === 'svg' ? 'application/octet-stream' : mimeTypes[ext] || 'application/octet-stream',
           'Content-Disposition': `attachment; filename="${basename}"`,
           'Content-Length': content.length,
+          'X-Content-Type-Options': 'nosniff',
         });
         reply.raw.end(content);
         return;
       }
       reply.header('Content-Type', mimeTypes[ext] || 'application/octet-stream');
+      reply.header('X-Content-Type-Options', 'nosniff');
       reply.send(content);
     } catch (err) {
       reply
@@ -380,4 +382,108 @@ export function registerFileRoutes(app: FastifyInstance, ctx: SessionPort): void
     const closed = fileStreamManager.closeStream(streamId);
     return { success: closed };
   });
+  // Session-scoped file download.
+  // Uses the same realpath-based workspace boundary as file preview/raw routes;
+  // the sensitive-path blocklist remains defense-in-depth, not the primary boundary.
+  const SENSITIVE_PATTERNS: RegExp[] = [
+    /^\/etc\/shadow$/,
+    /^\/etc\/gshadow$/,
+    /^\/etc\/master\.passwd$/,
+    new RegExp(`^${homedir().replace(/[.*+?^${}()|[\]\\]/g, '\\$&')}\\/\\.ssh\\/`),
+    /\/\.env$/,
+    /\/\.env\./,
+    /\/credentials(\.json|\.yml|\.yaml|\.xml)?$/i,
+    /\/\.aws\/credentials$/,
+    /\/\.gcloud\/credentials\.db$/,
+    /\/\.docker\/config\.json$/,
+  ];
+
+  function isSensitivePath(absPath: string): boolean {
+    return SENSITIVE_PATTERNS.some((pattern) => pattern.test(absPath));
+  }
+
+  app.get('/api/download', async (req, reply) => {
+    const { path: filePath, sessionId } = req.query as { path?: string; sessionId?: string };
+
+    if (!filePath) {
+      reply.code(400).send(createErrorResponse(ApiErrorCode.INVALID_INPUT, 'Missing path parameter'));
+      return;
+    }
+
+    if (!sessionId) {
+      reply.code(400).send(createErrorResponse(ApiErrorCode.INVALID_INPUT, 'Missing sessionId parameter'));
+      return;
+    }
+
+    const session = findSessionOrFail(ctx, sessionId);
+    const validated = validateSessionFilePath(session.workingDir, filePath);
+    if (!validated) {
+      reply.code(404).send(createErrorResponse(ApiErrorCode.NOT_FOUND, 'File not found'));
+      return;
+    }
+    const { resolvedPath } = validated;
+
+    // Check sensitive path blocklist
+    if (isSensitivePath(resolvedPath)) {
+      reply.code(403).send(createErrorResponse(ApiErrorCode.INVALID_INPUT, 'Access to this file is blocked'));
+      return;
+    }
+
+    try {
+      const stat = await fs.stat(resolvedPath);
+
+      if (!stat.isFile()) {
+        reply.code(400).send(createErrorResponse(ApiErrorCode.INVALID_INPUT, 'Path is not a file'));
+        return;
+      }
+
+      // 50MB size limit
+      const MAX_DOWNLOAD_SIZE = 50 * 1024 * 1024;
+      if (stat.size > MAX_DOWNLOAD_SIZE) {
+        reply
+          .code(400)
+          .send(
+            createErrorResponse(
+              ApiErrorCode.INVALID_INPUT,
+              `File too large (${Math.round(stat.size / 1024 / 1024)}MB > 50MB limit)`
+            )
+          );
+        return;
+      }
+
+      const ext = filePath.split('.').pop()?.toLowerCase() || '';
+      const mimeTypes: Record<string, string> = {
+        png: 'image/png',
+        jpg: 'image/jpeg',
+        jpeg: 'image/jpeg',
+        gif: 'image/gif',
+        webp: 'image/webp',
+        svg: 'image/svg+xml',
+        pdf: 'application/pdf',
+        json: 'application/json',
+        txt: 'text/plain',
+        md: 'text/markdown',
+        csv: 'text/csv',
+        xml: 'application/xml',
+        zip: 'application/zip',
+        gz: 'application/gzip',
+        tar: 'application/x-tar',
+      };
+
+      const filename = pathBasename(resolvedPath);
+      const content = await fs.readFile(resolvedPath);
+      // Bypass Fastify compression — write directly to raw response
+      reply.raw.writeHead(200, {
+        'Content-Type': mimeTypes[ext] || 'application/octet-stream',
+        'Content-Disposition': `attachment; filename="${filename}"`,
+        'Content-Length': content.length,
+      });
+      reply.raw.end(content);
+      return;
+    } catch (err) {
+      reply
+        .code(500)
+        .send(createErrorResponse(ApiErrorCode.OPERATION_FAILED, `Failed to read file: ${getErrorMessage(err)}`));
+    }
+  });
 }

src/web/server.ts

@@ -102,6 +102,7 @@ import { SseEvent } from './sse-events.js';
 import type { ScheduledRun } from './ports/index.js';
 import { registerAuthMiddleware, registerSecurityHeaders } from './middleware/auth.js';
 import { installRouteErrorHandler } from './route-error-handler.js';
+import { isExplicitlyEnabled, isLoopbackBindHost } from './network-auth-policy.js';
 import {
   registerPushRoutes,
   registerTeamRoutes,
@@ -191,6 +192,7 @@ export class WebServer extends EventEmitter {
   private sse: SseStreamManager;
   private store = getStore();
   private port: number;
+  private host: string;
   private https: boolean;
   private testMode: boolean;
   private mux: TerminalMultiplexer;
@@ -232,6 +234,10 @@ export class WebServer extends EventEmitter {
   private pushStore: PushSubscriptionStore = new PushSubscriptionStore();
   private teamWatcher: TeamWatcher = new TeamWatcher();
   private _orchestratorLoop: import('../orchestrator-loop.js').OrchestratorLoop | null = null;
+  private readonly titleHostname: string;
+  private readonly windowTitle: string;
+  private readonly indexHtmlTemplate: string;
+  private readonly allowUnauthenticatedNetwork: boolean;
   private _pasteImageGcStop: (() => void) | null = null;
   private _eventLoopMonitor: EventLoopMonitorHandle | null = null;
   private teamWatcherHandlers: {
@@ -240,15 +246,22 @@ export class WebServer extends EventEmitter {
     teamRemoved: (config: unknown) => void;
     taskUpdated: (data: unknown) => void;
   } | null = null;
-  private readonly titleHostname: string;
-  private readonly windowTitle: string;
-  private readonly indexHtmlTemplate: string;
-  constructor(port: number = 3000, https: boolean = false, testMode: boolean = false, titleHostname?: string) {
+  constructor(
+    port: number = 3000,
+    https: boolean = false,
+    testMode: boolean = false,
+    host: string = '127.0.0.1',
+    titleHostname?: string,
+    allowUnauthenticatedNetwork: boolean = false
+  ) {
     super();
     this.setMaxListeners(0);
+    this.host = host;
     this.port = port;
     this.https = https;
     this.testMode = testMode;
+    this.allowUnauthenticatedNetwork =
+      allowUnauthenticatedNetwork || isExplicitlyEnabled(process.env.CODEMAN_ALLOW_UNAUTHENTICATED_NETWORK);
     this.titleHostname = titleHostname || getHostname();
     this.windowTitle = `codeman:${this.titleHostname}`;
     this.indexHtmlTemplate = readFileSync(join(__dirname, 'public', 'index.html'), 'utf-8');
@@ -1646,6 +1659,13 @@ export class WebServer extends EventEmitter {
   }
 
   async start(): Promise<void> {
+    if (!isLoopbackBindHost(this.host) && !process.env.CODEMAN_PASSWORD && !this.allowUnauthenticatedNetwork) {
+      throw new Error(
+        'Refusing to start Codeman on a non-loopback host without CODEMAN_PASSWORD. ' +
+          'Set CODEMAN_PASSWORD or explicitly allow unauthenticated network access.'
+      );
+    }
+
     await this.setupRoutes();
 
     const lifecycleLog = getLifecycleLog();
@@ -1672,19 +1692,23 @@ export class WebServer extends EventEmitter {
       this._eventLoopMonitor = startEventLoopMonitor();
     }
 
-    await this.app.listen({ port: this.port, host: '0.0.0.0' });
+    await this.app.listen({ port: this.port, host: this.host });
     const protocol = this.https ? 'https' : 'http';
-    console.log(`Codeman web interface running at ${protocol}://localhost:${this.port}`);
+    const displayHost = this.host === '0.0.0.0' ? 'localhost' : this.host;
+    console.log(`Codeman web interface running at ${protocol}://${displayHost}:${this.port}`);
 
-    // Security warning: server binds to 0.0.0.0 (all interfaces) — warn if no auth configured
-    if (!process.env.CODEMAN_PASSWORD) {
+    if (!isLoopbackBindHost(this.host) && !process.env.CODEMAN_PASSWORD && this.allowUnauthenticatedNetwork) {
       console.warn('\n⚠  WARNING: No CODEMAN_PASSWORD set — server is accessible without authentication.');
       console.warn('   Anyone on your network can access and control Claude sessions.');
-      console.warn('   Set CODEMAN_PASSWORD environment variable to enable auth.\n');
+      console.warn(
+        '   This was explicitly allowed by --allow-unauthenticated-network or CODEMAN_ALLOW_UNAUTHENTICATED_NETWORK.\n'
+      );
     }
 
     // Set API URL for child processes (MCP server, spawned sessions)
-    process.env.CODEMAN_API_URL = `${protocol}://localhost:${this.port}`;
+    const apiHost =
+      this.host === '0.0.0.0' || this.host === 'localhost' || this.host === '::1' ? '127.0.0.1' : this.host;
+    process.env.CODEMAN_API_URL = `${protocol}://${apiHost}:${this.port}`;
 
     // Start scheduled runs cleanup timer
     this.cleanup.setInterval(
@@ -2176,9 +2200,11 @@ export async function startWebServer(
   port: number = 3000,
   https: boolean = false,
   testMode: boolean = false,
-  titleHostname?: string
+  host: string = '127.0.0.1',
+  titleHostname?: string,
+  allowUnauthenticatedNetwork: boolean = false
 ): Promise<WebServer> {
-  const server = new WebServer(port, https, testMode, titleHostname);
+  const server = new WebServer(port, https, testMode, host, titleHostname, allowUnauthenticatedNetwork);
   await server.start();
   return server;
 }