g1t/apps/web/app/lib/session.server.ts
| 1 | import { |
| 2 | type MiddlewareFunction, |
| 3 | type RouterContextProvider, |
| 4 | createContext, |
| 5 | data, |
| 6 | redirect, |
| 7 | } from "react-router"; |
| 8 | |
| 9 | import { type Result, type Role, type User, type Viewer, httpStatus } from "@g1t/contracts"; |
| 10 | |
| 11 | import { safeNext } from "./next"; |
| 12 | import { identity } from "./services.server"; |
| 13 | |
| 14 | const SESSION_COOKIE = "g1t_session"; |
| 15 | const SESSION_TTL_SECONDS = 30 * 24 * 60 * 60; |
| 16 | |
| 17 | const viewerContext = createContext<Viewer>(null); |
| 18 | |
| 19 | function sessionToken(request: Request): string | null { |
| 20 | const cookies = request.headers.get("cookie") ?? ""; |
| 21 | const match = new RegExp(`(?:^|; )${SESSION_COOKIE}=([0-9a-f]{64})`).exec(cookies); |
| 22 | return match ? match[1] : null; |
| 23 | } |
| 24 | |
| 25 | function sessionCookie(value: string, maxAge: number): string { |
| 26 | return `${SESSION_COOKIE}=${value}; Path=/; HttpOnly; Secure; SameSite=Lax; Max-Age=${maxAge}`; |
| 27 | } |
| 28 | |
| 29 | /** Pages a signed-in person can use before they have a workspace. */ |
| 30 | const BEFORE_WORKSPACE = ["/workspaces/new", "/settings", "/verify", "/logout", "/auth/github", "/auth/github/callback"]; |
| 31 | |
| 32 | /** |
| 33 | * Root middleware: resolves the signed-in user once per request. |
| 34 | * |
| 35 | * Everything on g1t lives in a workspace, so a confirmed account with none |
| 36 | * is sent to create one, from wherever it was going, and returned there |
| 37 | * afterwards. |
| 38 | */ |
| 39 | export const viewerMiddleware: MiddlewareFunction<Response> = async ({ |
| 40 | request, |
| 41 | context, |
| 42 | }) => { |
| 43 | const token = sessionToken(request); |
| 44 | if (!token) return; |
| 45 | const viewer = await identity.userForSession(token); |
| 46 | context.set(viewerContext, viewer); |
| 47 | |
| 48 | const { pathname, search } = new URL(request.url); |
| 49 | if ( |
| 50 | request.method === "GET" && |
| 51 | viewer?.verified && |
| 52 | (viewer.workspaces ?? []).length === 0 && |
| 53 | // Someone a repository is shared with can use it without a workspace. |
| 54 | (viewer.grants ?? []).length === 0 && |
| 55 | !BEFORE_WORKSPACE.includes(pathname) && |
| 56 | // An invite to a workspace is how someone without one gets one, and an |
| 57 | // invitation to a repository is answered before anything else. |
| 58 | !pathname.startsWith("/invite/") && |
| 59 | !/^\/[^/]+\/[^/]+\/invitations\/?$/.test(pathname) && |
| 60 | !pathname.endsWith(".data") |
| 61 | ) { |
| 62 | const next = pathname === "/" ? "" : `?next=${encodeURIComponent(pathname + search)}`; |
| 63 | throw redirect(`/workspaces/new${next}`); |
| 64 | } |
| 65 | }; |
| 66 | |
| 67 | type Context = Readonly<RouterContextProvider>; |
| 68 | |
| 69 | export function getViewer(context: Context): Viewer { |
| 70 | return context.get(viewerContext); |
| 71 | } |
| 72 | |
| 73 | /** The viewer's role in a workspace, or null if they are not a member. */ |
| 74 | export function roleIn(viewer: Viewer, slug: string): Role | null { |
| 75 | const wanted = slug.toLowerCase(); |
| 76 | return ( |
| 77 | viewer?.workspaces?.find((membership) => membership.slug === wanted)?.role ?? null |
| 78 | ); |
| 79 | } |
| 80 | |
| 81 | export function requireUser(context: Context, request: Request): User { |
| 82 | const viewer = getViewer(context); |
| 83 | if (!viewer) { |
| 84 | // Keep the query string: a device sign-in link carries its code there. |
| 85 | const { pathname, search } = new URL(request.url); |
| 86 | throw redirect(`/login?next=${encodeURIComponent(pathname + search)}`); |
| 87 | } |
| 88 | return viewer; |
| 89 | } |
| 90 | |
| 91 | /** |
| 92 | * Where to go after signing in. Only same-site paths are honoured, so |
| 93 | * `next` cannot redirect off g1t. |
| 94 | */ |
| 95 | export function nextPath(request: Request): string { |
| 96 | return safeNext(new URL(request.url).searchParams.get("next")); |
| 97 | } |
| 98 | |
| 99 | /** `Set-Cookie` value that starts a session. */ |
| 100 | export function startSession(token: string): string { |
| 101 | return sessionCookie(token, SESSION_TTL_SECONDS); |
| 102 | } |
| 103 | |
| 104 | /** Ends the session and returns the `Set-Cookie` value that clears it. */ |
| 105 | export async function endSession(request: Request): Promise<string> { |
| 106 | const token = sessionToken(request); |
| 107 | if (token) await identity.signOut(token); |
| 108 | return sessionCookie("", 0); |
| 109 | } |
| 110 | |
| 111 | /** The session token the request carries, for proof of a recent sign-in. */ |
| 112 | export function sessionTokenOf(request: Request): string | null { |
| 113 | return sessionToken(request); |
| 114 | } |
| 115 | |
| 116 | /** The visitor's IP address, as Cloudflare saw it, for rate limits. */ |
| 117 | export function clientOf(request: Request): string | null { |
| 118 | return request.headers.get("cf-connecting-ip"); |
| 119 | } |
| 120 | |
| 121 | /** Rejects cross-site form posts; call at the top of every action. */ |
| 122 | export function assertSameOrigin(request: Request): void { |
| 123 | const origin = request.headers.get("origin"); |
| 124 | if (origin && origin !== new URL(request.url).origin) { |
| 125 | throw new Response("Cross-origin request rejected", { status: 403 }); |
| 126 | } |
| 127 | } |
| 128 | |
| 129 | /** The value of a service result, or the matching HTTP error. */ |
| 130 | export function unwrap<T>(result: Result<T>): T { |
| 131 | if (result.ok) return result.value; |
| 132 | throw data(result.error.message, { status: httpStatus(result.error) }); |
| 133 | } |