88 lines
3.5 KiB
TypeScript
88 lines
3.5 KiB
TypeScript
import crypto from "crypto";
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import type { IncomingMessage, OutgoingMessage } from "http";
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import { z } from "zod";
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import { IS_PRODUCTION } from "@calcom/lib/constants";
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import { WEBAPP_URL } from "@calcom/lib/constants";
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function getCspPolicy(nonce: string) {
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//TODO: Do we need to explicitly define it in turbo.json
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const CSP_POLICY = process.env.CSP_POLICY;
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// Note: "non-strict" policy only allows inline styles otherwise it's the same as "strict"
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// We can remove 'unsafe-inline' from style-src when we add nonces to all style tags
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// Maybe see how @next-safe/middleware does it if it's supported.
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const useNonStrictPolicy = CSP_POLICY === "non-strict";
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// We add WEBAPP_URL to img-src because of booking pages, which end up loading images from app.cal.com on cal.com
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// FIXME: Write a layer to extract out EventType Analytics tracking endpoints and add them to img-src or connect-src as needed. e.g. fathom, Google Analytics and others
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return `
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default-src 'self' ${IS_PRODUCTION ? "" : "data:"};
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script-src ${
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IS_PRODUCTION
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? // 'self' 'unsafe-inline' https: added for Browsers not supporting strict-dynamic not supporting strict-dynamic
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"'nonce-" + nonce + "' 'strict-dynamic' 'self' 'unsafe-inline' https:"
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: // Note: We could use 'strict-dynamic' with 'nonce-..' instead of unsafe-inline but there are some streaming related scripts that get blocked(because they don't have nonce on them). It causes a really frustrating full page error model by Next.js to show up sometimes
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"'unsafe-inline' 'unsafe-eval' https: http:"
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};
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object-src 'none';
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base-uri 'none';
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child-src app.cal.com;
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style-src 'self' ${
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IS_PRODUCTION ? (useNonStrictPolicy ? "'unsafe-inline'" : "") : "'unsafe-inline'"
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} app.cal.com;
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font-src 'self';
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img-src 'self' ${WEBAPP_URL} https://www.gravatar.com https://img.youtube.com https://eu.ui-avatars.com/api/ data:;
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connect-src 'self'
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`;
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}
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// Taken from @next-safe/middleware
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const isPagePathRequest = (url: URL) => {
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const isNonPagePathPrefix = /^\/(?:_next|api)\//;
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const isFile = /\..*$/;
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const { pathname } = url;
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return !isNonPagePathPrefix.test(pathname) && !isFile.test(pathname);
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};
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export function csp(req: IncomingMessage | null, res: OutgoingMessage | null) {
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if (!req) {
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return { nonce: undefined };
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}
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const existingNonce = req.headers["x-nonce"];
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if (existingNonce) {
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const existingNoneParsed = z.string().safeParse(existingNonce);
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return { nonce: existingNoneParsed.success ? existingNoneParsed.data : "" };
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}
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if (!req.url) {
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return { nonce: undefined };
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}
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const CSP_POLICY = process.env.CSP_POLICY;
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const cspEnabledForInstance = CSP_POLICY;
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const nonce = crypto.randomBytes(16).toString("base64");
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const parsedUrl = new URL(req.url, "http://base_url");
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const cspEnabledForPage = cspEnabledForInstance && isPagePathRequest(parsedUrl);
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if (!cspEnabledForPage) {
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return {
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nonce: undefined,
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};
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}
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// Set x-nonce request header to be used by `getServerSideProps` or similar fns and `Document.getInitialProps` to read the nonce from
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// It is generated for all page requests but only used by pages that need CSP
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req.headers["x-nonce"] = nonce;
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if (res) {
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res.setHeader(
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req.headers["x-csp-enforce"] === "true"
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? "Content-Security-Policy"
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: "Content-Security-Policy-Report-Only",
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getCspPolicy(nonce)
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.replace(/\s{2,}/g, " ")
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.trim()
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);
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}
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return { nonce };
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}
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