Handle authentication with proxy

The cookie will be set for the proxy domain so it'll work for all of its
subdomains.

Author: code-asher

src/node/app/proxy.ts

@@ -1,50 +1,52 @@
 import * as http from "http"
 import { HttpCode, HttpError } from "../../common/http"
-import { AuthType, HttpProvider, HttpProviderOptions, HttpResponse, Route } from "../http"
+import { HttpProvider, HttpProviderOptions, HttpProxyProvider, HttpResponse, Route } from "../http"
 
 /**
  * Proxy HTTP provider.
  */
-export class ProxyHttpProvider extends HttpProvider {
-  public constructor(options: HttpProviderOptions, private readonly proxyDomains: string[]) {
+export class ProxyHttpProvider extends HttpProvider implements HttpProxyProvider {
+  public readonly proxyDomains: string[]
+
+  public constructor(options: HttpProviderOptions, proxyDomains: string[] = []) {
     super(options)
+    this.proxyDomains = proxyDomains.map((d) => d.replace(/^\*\./, "")).filter((d, i, arr) => arr.indexOf(d) === i)
   }
 
-  public async handleRequest(route: Route): Promise<HttpResponse> {
-    if (this.options.auth !== AuthType.Password || route.requestPath !== "/index.html") {
-      throw new HttpError("Not found", HttpCode.NotFound)
+  public async handleRequest(route: Route, request: http.IncomingMessage): Promise<HttpResponse> {
+    if (!this.authenticated(request)) {
+      if (route.requestPath === "/index.html") {
+        return { redirect: "/login", query: { to: route.fullPath } }
+      }
+      throw new HttpError("Unauthorized", HttpCode.Unauthorized)
     }
+
     const payload = this.proxy(route.base.replace(/^\//, ""))
-    if (!payload) {
-      throw new HttpError("Not found", HttpCode.NotFound)
+    if (payload) {
+      return payload
     }
-    return payload
+
+    throw new HttpError("Not found", HttpCode.NotFound)
   }
 
-  public async getRoot(route: Route, error?: Error): Promise<HttpResponse> {
-    const response = await this.getUtf8Resource(this.rootPath, "src/browser/pages/login.html")
-    response.content = response.content.replace(/{{ERROR}}/, error ? `<div class="error">${error.message}</div>` : "")
-    return this.replaceTemplates(route, response)
+  public getProxyDomain(host?: string): string | undefined {
+    if (!host || !this.proxyDomains) {
+      return undefined
+    }
+
+    return this.proxyDomains.find((d) => host.endsWith(d))
   }
 
-  /**
-   * Return a response if the request should be proxied. Anything that ends in a
-   * proxy domain and has a subdomain should be proxied. The port is found in
-   * the top-most subdomain.
-   *
-   * For example, if the proxy domain is `coder.com` then `8080.coder.com` and
-   * `test.8080.coder.com` will both proxy to `8080` but `8080.test.coder.com`
-   * will have an error because `test` isn't a port. If the proxy domain was
-   * `test.coder.com` then it would work.
-   */
   public maybeProxy(request: http.IncomingMessage): HttpResponse | undefined {
-    const host = request.headers.host
-    if (!host || !this.proxyDomains) {
+    // No proxy until we're authenticated. This will cause the login page to
+    // show as well as let our assets keep loading normally.
+    if (!this.authenticated(request)) {
       return undefined
     }
 
-    const proxyDomain = this.proxyDomains.find((d) => host.endsWith(d))
-    if (!proxyDomain) {
+    const host = request.headers.host
+    const proxyDomain = this.getProxyDomain(host)
+    if (!host || !proxyDomain) {
       return undefined
     }
 

src/node/entry.ts

@@ -46,19 +46,11 @@ const main = async (args: Args): Promise<void> => {
     throw new Error("--cert-key is missing")
   }
 
-  /**
-   * Domains can be in the form `coder.com` or `*.coder.com`. Either way,
-   * `[number].coder.com` will be proxied to `number`.
-   */
-  const proxyDomains = args["proxy-domain"]
-    ? args["proxy-domain"].map((d) => d.replace(/^\*\./, "")).filter((d, i, arr) => arr.indexOf(d) === i)
-    : []
-
   const httpServer = new HttpServer(options)
   const vscode = httpServer.registerHttpProvider("/", VscodeHttpProvider, args)
   const api = httpServer.registerHttpProvider("/api", ApiHttpProvider, httpServer, vscode, args["user-data-dir"])
   const update = httpServer.registerHttpProvider("/update", UpdateHttpProvider, !args["disable-updates"])
-  const proxy = httpServer.registerHttpProvider("/proxy", ProxyHttpProvider, proxyDomains)
+  const proxy = httpServer.registerHttpProvider("/proxy", ProxyHttpProvider, args["proxy-domain"])
   httpServer.registerHttpProvider("/login", LoginHttpProvider)
   httpServer.registerHttpProvider("/static", StaticHttpProvider)
   httpServer.registerHttpProvider("/dashboard", DashboardHttpProvider, api, update)
@@ -109,11 +101,11 @@ const main = async (args: Args): Promise<void> => {
     logger.info("  - Not serving HTTPS")
   }
 
-  if (proxyDomains.length === 1) {
-    logger.info(`  - Proxying *.${proxyDomains[0]}`)
-  } else if (proxyDomains && proxyDomains.length > 1) {
+  if (proxy.proxyDomains.length === 1) {
+    logger.info(`  - Proxying *.${proxy.proxyDomains[0]}`)
+  } else if (proxy.proxyDomains.length > 1) {
     logger.info("  - Proxying the following domains:")
-    proxyDomains.forEach((domain) => logger.info(`    - *.${domain}`))
+    proxy.proxyDomains.forEach((domain) => logger.info(`    - *.${domain}`))
   }
 
   logger.info(`Automatic updates are ${update.enabled ? "enabled" : "disabled"}`)

src/node/http.ts

@@ -395,7 +395,29 @@ export interface HttpProvider3<A1, A2, A3, T> {
 }
 
 export interface HttpProxyProvider {
+  /**
+   * Return a response if the request should be proxied. Anything that ends in a
+   * proxy domain and has a subdomain should be proxied. The port is found in
+   * the top-most subdomain.
+   *
+   * For example, if the proxy domain is `coder.com` then `8080.coder.com` and
+   * `test.8080.coder.com` will both proxy to `8080` but `8080.test.coder.com`
+   * will have an error because `test` isn't a port. If the proxy domain was
+   * `test.coder.com` then it would work.
+   */
   maybeProxy(request: http.IncomingMessage): HttpResponse | undefined
+
+  /**
+   * Get the matching proxy domain based on the provided host.
+   */
+  getProxyDomain(host: string): string | undefined
+
+  /**
+   * Domains can be provided in the form `coder.com` or `*.coder.com`. Either
+   * way, `<number>.coder.com` will be proxied to `number`. The domains are
+   * stored here without the `*.`.
+   */
+  readonly proxyDomains: string[]
 }
 
 /**
@@ -538,7 +560,13 @@ export class HttpServer {
               "Set-Cookie": [
                 `${payload.cookie.key}=${payload.cookie.value}`,
                 `Path=${normalize(payload.cookie.path || "/", true)}`,
-                request.headers.host ? `Domain=${request.headers.host}` : undefined,
+                // Set the cookie against the host so it can be used in
+                // subdomains. Use a matching proxy domain if possible so
+                // requests to any of those subdomains will already be
+                // authenticated.
+                request.headers.host
+                  ? `Domain=${(this.proxy && this.proxy.getProxyDomain(request.headers.host)) || request.headers.host}`
+                  : undefined,
                 // "HttpOnly",
                 "SameSite=strict",
               ]
@@ -566,8 +594,8 @@ export class HttpServer {
 
     try {
       const payload =
-        (this.proxy && this.proxy.maybeProxy(request)) ||
         this.maybeRedirect(request, route) ||
+        (this.proxy && this.proxy.maybeProxy(request)) ||
         (await route.provider.handleRequest(route, request))
       if (!payload) {
         throw new HttpError("Not found", HttpCode.NotFound)