Add protected handlers for next (#121)

* Add protected handlers for next

* Remove unneeded awaits

src/get-app-id.ts

@@ -0,0 +1,43 @@
+import { AuthData } from "./APL";
+import { createDebug } from "./debug";
+
+const debug = createDebug("getAppId");
+
+type GetIdResponseType = {
+  data?: {
+    app?: {
+      id: string;
+    };
+  };
+};
+
+export const getAppId = async (authData: AuthData): Promise<string | undefined> => {
+  try {
+    const response = await fetch(`https://${authData.domain}/graphql/`, {
+      method: "POST",
+      headers: {
+        "Content-Type": "application/json",
+        Authorization: `Bearer ${authData.token}`,
+      },
+      body: JSON.stringify({
+        query: `
+        {
+          app{
+            id
+          }
+        }
+        `,
+      }),
+    });
+    if (response.status !== 200) {
+      debug(`Could not get the app ID: Saleor API has response code ${response.status}`);
+      return undefined;
+    }
+    const body = (await response.json()) as GetIdResponseType;
+    const appId = body.data?.app?.id;
+    return appId;
+  } catch (e) {
+    debug("Could not get the app ID: %O", e);
+    return undefined;
+  }
+};

src/handlers/next/create-protected-handler.ts

@@ -0,0 +1,57 @@
+import { NextApiHandler, NextApiRequest, NextApiResponse } from "next";
+
+import { APL } from "../../APL";
+import { createDebug } from "../../debug";
+import { ProtectedHandlerContext } from "./process-async-saleor-webhook";
+import {
+  processSaleorProtectedHandler,
+  ProtectedHandlerError,
+  SaleorProtectedHandlerError,
+} from "./process-protected-handler";
+
+const debug = createDebug("ProtectedHandler");
+
+export const ProtectedHandlerErrorCodeMap: Record<SaleorProtectedHandlerError, number> = {
+  OTHER: 500,
+  MISSING_HOST_HEADER: 400,
+  MISSING_DOMAIN_HEADER: 400,
+  NOT_REGISTERED: 401,
+  JWT_VERIFICATION_FAILED: 401,
+  NO_APP_ID: 401,
+  MISSING_AUTHORIZATION_BEARER_HEADER: 400,
+};
+
+export type NextProtectedApiHandler<TResp = unknown> = (
+  req: NextApiRequest,
+  res: NextApiResponse<TResp>,
+  ctx: ProtectedHandlerContext
+) => unknown | Promise<unknown>;
+
+/**
+ * Wraps provided function, to ensure incoming request comes from Saleor Dashboard.
+ * Also provides additional `context` object containing request properties.
+ */
+export const createProtectedHandler =
+  (handlerFn: NextProtectedApiHandler, apl: APL): NextApiHandler =>
+  (req, res) => {
+    debug("Protected handler called");
+    processSaleorProtectedHandler({
+      req,
+      apl,
+    })
+      .then(async (context) => {
+        debug("Incoming request validated. Call handlerFn");
+        return handlerFn(req, res, context);
+      })
+      .catch((e) => {
+        debug("Unexpected error during processing the request");
+
+        if (e instanceof ProtectedHandlerError) {
+          debug(`Validation error: ${e.message}`);
+          res.status(ProtectedHandlerErrorCodeMap[e.errorType] || 400).end();
+          return;
+        }
+        debug("Unexpected error: %O", e);
+        res.status(500).end();
+      });
+  };

src/handlers/next/index.ts

@@ -1,3 +1,5 @@
 export * from "./create-app-register-handler";
 export * from "./create-manifest-handler";
+export * from "./create-protected-handler";
+export * from "./process-protected-handler";
 export * from "./saleor-async-webhook";

src/handlers/next/process-async-saleor-webhook.ts

@@ -43,6 +43,11 @@ export type WebhookContext<T> = {
   authData: AuthData;
 };
 
+export type ProtectedHandlerContext = {
+  baseUrl: string;
+  authData: AuthData;
+};
+
 interface ProcessSaleorWebhookArgs {
   req: NextApiRequest;
   apl: APL;

src/handlers/next/process-protected-handler.test.ts

@@ -0,0 +1,125 @@
+import { NextApiRequest } from "next/types";
+import { createMocks } from "node-mocks-http";
+import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
+
+import { APL } from "../../APL";
+import { getAppId } from "../../get-app-id";
+import { verifyJWT } from "../../verify-jwt";
+import { processSaleorProtectedHandler } from "./process-protected-handler";
+
+const validToken =
+  "eyJ0eXAiOiJKV1QiLCJhbGciOiJFUzI1NiIsImtpZCI6Ijk4ZTEzNDk4YmM5NThjM2QyNzk2NjY5Zjk0NzYxMzZkIn0.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.PUyvuUlDvUBXMGSaexusdlkY5wF83M8tsjefVXOknaKuVgLbafvLOgx78YGVB4kdAybC7O3Yjs7IIFOzz5U80Q";
+
+const validAppId = "QXBwOjI3NQ==";
+
+vi.mock("./../../get-app-id", () => ({
+  // eslint-disable-next-line @typescript-eslint/no-unused-vars
+  getAppId: vi.fn(),
+}));
+
+vi.mock("./../../verify-jwt", () => ({
+  // eslint-disable-next-line @typescript-eslint/no-unused-vars
+  verifyJWT: vi.fn(),
+}));
+
+describe("processSaleorProtectedHandler", () => {
+  let mockRequest: NextApiRequest;
+
+  const mockAPL: APL = {
+    get: async (domain: string) =>
+      domain === "example.com"
+        ? {
+            domain: "example.com",
+            token: "mock-token",
+          }
+        : undefined,
+    set: vi.fn(),
+    delete: vi.fn(),
+    getAll: vi.fn(),
+    isReady: vi.fn(),
+    isConfigured: vi.fn(),
+  };
+
+  beforeEach(() => {
+    // Create request method which passes all the tests
+    const { req } = createMocks({
+      headers: {
+        host: "some-saleor-host.cloud",
+        "x-forwarded-proto": "https",
+        "saleor-domain": "example.com",
+        "saleor-event": "product_updated",
+        "saleor-signature": "mocked_signature",
+        "authorization-bearer": validToken,
+      },
+      method: "POST",
+    });
+    mockRequest = req;
+  });
+
+  afterEach(() => {
+    vi.resetAllMocks();
+  });
+
+  it("Process valid request", async () => {
+    vi.mocked(getAppId).mockResolvedValue(validAppId);
+    vi.mocked(verifyJWT).mockResolvedValue();
+
+    expect(await processSaleorProtectedHandler({ apl: mockAPL, req: mockRequest })).toStrictEqual({
+      authData: {
+        domain: "example.com",
+        token: "mock-token",
+      },
+      baseUrl: "https://some-saleor-host.cloud",
+    });
+  });
+
+  it("Throw error when app ID can't be fetched", async () => {
+    vi.mocked(getAppId).mockResolvedValue("");
+
+    await expect(processSaleorProtectedHandler({ apl: mockAPL, req: mockRequest })).rejects.toThrow(
+      "Could not get the app ID from the domain example.com"
+    );
+  });
+
+  it("Throw error when domain header is missing", async () => {
+    vi.mocked(getAppId).mockResolvedValue(validAppId);
+    vi.mocked(verifyJWT).mockResolvedValue();
+
+    delete mockRequest.headers["saleor-domain"];
+
+    await expect(processSaleorProtectedHandler({ apl: mockAPL, req: mockRequest })).rejects.toThrow(
+      "Missing saleor-domain header"
+    );
+  });
+
+  it("Throw error when token header is missing", async () => {
+    vi.mocked(getAppId).mockResolvedValue(validAppId);
+    vi.mocked(verifyJWT).mockResolvedValue();
+
+    delete mockRequest.headers["authorization-bearer"];
+
+    await expect(processSaleorProtectedHandler({ apl: mockAPL, req: mockRequest })).rejects.toThrow(
+      "Missing authorization-bearer header"
+    );
+  });
+
+  it("Throw error when APL has no auth data for the given domain", async () => {
+    vi.mocked(getAppId).mockResolvedValue(validAppId);
+    vi.mocked(verifyJWT).mockResolvedValue();
+
+    mockRequest.headers["saleor-domain"] = "wrong.example.com";
+
+    await expect(processSaleorProtectedHandler({ apl: mockAPL, req: mockRequest })).rejects.toThrow(
+      "Can't find auth data for domain wrong.example.com. Please register the application"
+    );
+  });
+
+  it("Throw error when token verification fails", async () => {
+    vi.mocked(getAppId).mockResolvedValue(validAppId);
+    vi.mocked(verifyJWT).mockRejectedValue("Verification error");
+
+    await expect(processSaleorProtectedHandler({ apl: mockAPL, req: mockRequest })).rejects.toThrow(
+      "JWT verification failed: "
+    );
+  });
+});

src/handlers/next/process-protected-handler.ts

@@ -0,0 +1,106 @@
+import { NextApiRequest } from "next";
+
+import { APL } from "../../APL";
+import { AuthData } from "../../APL/apl";
+import { createDebug } from "../../debug";
+import { getAppId } from "../../get-app-id";
+import { getBaseUrl, getSaleorHeaders } from "../../headers";
+import { verifyJWT } from "../../verify-jwt";
+
+const debug = createDebug("processProtectedHandler");
+
+export type SaleorProtectedHandlerError =
+  | "OTHER"
+  | "MISSING_HOST_HEADER"
+  | "MISSING_DOMAIN_HEADER"
+  | "MISSING_AUTHORIZATION_BEARER_HEADER"
+  | "NOT_REGISTERED"
+  | "JWT_VERIFICATION_FAILED"
+  | "NO_APP_ID";
+
+export class ProtectedHandlerError extends Error {
+  errorType: SaleorProtectedHandlerError = "OTHER";
+
+  constructor(message: string, errorType: SaleorProtectedHandlerError) {
+    super(message);
+    if (errorType) {
+      this.errorType = errorType;
+    }
+    Object.setPrototypeOf(this, ProtectedHandlerError.prototype);
+  }
+}
+
+export type ProtectedHandlerContext = {
+  baseUrl: string;
+  authData: AuthData;
+};
+
+interface ProcessSaleorProtectedHandlerArgs {
+  req: NextApiRequest;
+  apl: APL;
+}
+
+type ProcessAsyncSaleorProtectedHandler = (
+  props: ProcessSaleorProtectedHandlerArgs
+) => Promise<ProtectedHandlerContext>;
+
+/**
+ * Perform security checks on given request and return ProtectedHandlerContext object.
+ * In case of validation issues, instance of the ProtectedHandlerError will be thrown.
+ */
+export const processSaleorProtectedHandler: ProcessAsyncSaleorProtectedHandler = async ({
+  req,
+  apl,
+}: ProcessSaleorProtectedHandlerArgs): Promise<ProtectedHandlerContext> => {
+  debug("Request processing started");
+  const { domain, authorizationBearer: token } = getSaleorHeaders(req.headers);
+
+  const baseUrl = getBaseUrl(req.headers);
+  if (!baseUrl) {
+    debug("Missing host header");
+    throw new ProtectedHandlerError("Missing host header", "MISSING_HOST_HEADER");
+  }
+
+  if (!domain) {
+    debug("Missing saleor-domain header");
+    throw new ProtectedHandlerError("Missing saleor-domain header", "MISSING_DOMAIN_HEADER");
+  }
+
+  if (!token) {
+    debug("Missing authorization-bearer header");
+    throw new ProtectedHandlerError(
+      "Missing authorization-bearer header",
+      "MISSING_AUTHORIZATION_BEARER_HEADER"
+    );
+  }
+
+  // Check if domain has been registered in the APL
+  const authData = await apl.get(domain);
+  if (!authData) {
+    debug("APL didn't found auth data for domain %s", domain);
+    throw new ProtectedHandlerError(
+      `Can't find auth data for domain ${domain}. Please register the application`,
+      "NOT_REGISTERED"
+    );
+  }
+
+  const appId = await getAppId(authData);
+  if (!appId) {
+    debug("Could not get the app ID.");
+    throw new ProtectedHandlerError(
+      `Could not get the app ID from the domain ${domain}`,
+      "NO_APP_ID"
+    );
+  }
+
+  try {
+    await verifyJWT({ appId, token, domain });
+  } catch (e) {
+    throw new ProtectedHandlerError("JWT verification failed: ", "JWT_VERIFICATION_FAILED");
+  }
+
+  return {
+    baseUrl,
+    authData,
+  };
+};

src/handlers/next/saleor-async-webhook.ts

@@ -34,7 +34,7 @@ type WebhookManifestConfiguration =
   | WebhookManifestConfigurationWithAst
   | WebhookManifestConfigurationWithQuery;
 
-export const ErrorCodeMap: Record<SaleorWebhookError, number> = {
+export const AsyncWebhookErrorCodeMap: Record<SaleorWebhookError, number> = {
   OTHER: 500,
   MISSING_HOST_HEADER: 400,
   MISSING_DOMAIN_HEADER: 400,
@@ -145,7 +145,7 @@ export class SaleorAsyncWebhook<TPayload = unknown> {
 
           if (e instanceof WebhookError) {
             debug(`Validation error: ${e.message}`);
-            res.status(ErrorCodeMap[e.errorType] || 400).end();
+            res.status(AsyncWebhookErrorCodeMap[e.errorType] || 400).end();
             return;
           }
           debug("Unexpected error: %O", e);

src/infer-webhooks.ts

@@ -12,6 +12,7 @@ const dropFileExtension = (filename: string) => path.parse(filename).name;
 export const inferWebhooks = async (
   baseURL: string,
   webhooksPath: string,
+  // eslint-disable-next-line @typescript-eslint/no-explicit-any
   generatedGraphQL: any
 ) => {
   let entries;
@@ -38,6 +39,7 @@ export const inferWebhooks = async (
     const statement = `${camelCaseName}SubscriptionDocument`;
     let query: string;
     if (statement in generatedGraphQL) {
+      // eslint-disable-next-line @typescript-eslint/no-explicit-any
       query = print((generatedGraphQL as any)[statement]);
     } else {
       throw Error("Subscription not found.");

src/verify-jwt.test.ts

@@ -0,0 +1,44 @@
+import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
+
+import { verifyJWT } from "./verify-jwt";
+
+const validToken =
+  "eyJ0eXAiOiJKV1QiLCJhbGciOiJFUzI1NiIsImtpZCI6Ijk4ZTEzNDk4YmM5NThjM2QyNzk2NjY5Zjk0NzYxMzZkIn0.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.PUyvuUlDvUBXMGSaexusdlkY5wF83M8tsjefVXOknaKuVgLbafvLOgx78YGVB4kdAybC7O3Yjs7IIFOzz5U80Q";
+
+const validDomain = "demo.eu.saleor.cloud";
+
+const validAppId = "QXBwOjI3NQ==";
+
+describe("verifyJWT", () => {
+  beforeEach(() => {
+    vi.mock("jose", async () => {
+      const original = await vi.importActual("jose");
+      return {
+        // @ts-ignore
+        ...original,
+        createRemoteJWKSet: vi.fn().mockImplementation(() => ""),
+        jwtVerify: vi.fn().mockImplementation(() => ""),
+      };
+    });
+  });
+
+  afterEach(() => {
+    vi.restoreAllMocks();
+  });
+
+  it("Process valid request", async () => {
+    await verifyJWT({ appId: validAppId, domain: validDomain, token: validToken });
+  });
+
+  it("Throw error on decode issue", async () => {
+    await expect(
+      verifyJWT({ appId: validAppId, domain: validDomain, token: "wrong_token" })
+    ).rejects.toThrow("JWT verification failed: Could not decode authorization token.");
+  });
+
+  it("Throw error on app ID missmatch", async () => {
+    await expect(
+      verifyJWT({ appId: "wrong_id", domain: validDomain, token: validToken })
+    ).rejects.toThrow("JWT verification failed: Token's app property is different than app ID.");
+  });
+});

src/verify-jwt.ts

@@ -0,0 +1,52 @@
+import * as jose from "jose";
+
+import { createDebug } from "./debug";
+import { getJwksUrl } from "./urls";
+
+const debug = createDebug("verify-jwt");
+
+export interface DashboardTokenPayload extends jose.JWTPayload {
+  app: string;
+}
+
+export interface verifyJWTArguments {
+  appId: string;
+  domain: string;
+  token: string;
+}
+
+export const verifyJWT = async ({ domain, token, appId }: verifyJWTArguments) => {
+  let tokenClaims: DashboardTokenPayload;
+  const ERROR_MESSAGE = "JWT verification failed:";
+
+  try {
+    tokenClaims = jose.decodeJwt(token as string) as DashboardTokenPayload;
+    debug("Token Claims decoded from jwt");
+  } catch (e) {
+    debug("Token Claims could not be decoded from JWT, will respond with Bad Request");
+    throw new Error(`${ERROR_MESSAGE} Could not decode authorization token.`);
+  }
+
+  if (tokenClaims.app !== appId) {
+    debug(
+      "Resolved App ID value from token to be different than in request, will respond with Bad Request"
+    );
+
+    throw new Error(`${ERROR_MESSAGE} Token's app property is different than app ID.`);
+  }
+
+  try {
+    debug("Trying to create JWKS");
+
+    const JWKS = jose.createRemoteJWKSet(new URL(getJwksUrl(domain)));
+    debug("Trying to compare JWKS with token");
+    await jose.jwtVerify(token, JWKS);
+  } catch (e) {
+    debug("Failure: %s", e);
+    debug("Will return with Bad Request");
+
+    console.error(e);
+
+    throw new Error(`${ERROR_MESSAGE} JWT signature verification failed.`);
+  }
+};