Merge branch 'dev' into chore/docker

backend/src/app.ts

@@ -11,7 +11,9 @@ import assignmentRouter from './routes/assignment.js';
 import submissionRouter from './routes/submission.js';
 import classRouter from './routes/class.js';
 import questionRouter from './routes/question.js';
-import loginRouter from './routes/login.js';
+import authRouter from './routes/auth.js';
+import { authenticateUser } from './middleware/auth/auth.js';
+import cors from './middleware/cors.js';
 import { getLogger, Logger } from './logging/initalize.js';
 import { responseTimeLogger } from './logging/responseTimeLogger.js';
 import responseTime from 'response-time';
@@ -22,8 +24,10 @@ const logger: Logger = getLogger();
 const app: Express = express();
 const port: string | number = getNumericEnvVar(EnvVars.Port);
 
+app.use(cors);
 app.use(express.json());
 app.use(responseTime(responseTimeLogger));
+app.use(authenticateUser);
 
 // TODO Replace with Express routes
 app.get('/', (_, res: Response) => {
@@ -39,8 +43,7 @@ app.use('/assignment', assignmentRouter);
 app.use('/submission', submissionRouter);
 app.use('/class', classRouter);
 app.use('/question', questionRouter);
-app.use('/login', loginRouter);
-
+app.use('/auth', authRouter);
 app.use('/theme', themeRoutes);
 app.use('/learningPath', learningPathRoutes);
 app.use('/learningObject', learningObjectRoutes);

backend/src/controllers/auth.ts

@@ -0,0 +1,33 @@
+import { EnvVars, getEnvVar } from '../util/envvars.js';
+
+type FrontendIdpConfig = {
+    authority: string;
+    clientId: string;
+    scope: string;
+    responseType: string;
+};
+
+type FrontendAuthConfig = {
+    student: FrontendIdpConfig;
+    teacher: FrontendIdpConfig;
+};
+
+const SCOPE = 'openid profile email';
+const RESPONSE_TYPE = 'code';
+
+export function getFrontendAuthConfig(): FrontendAuthConfig {
+    return {
+        student: {
+            authority: getEnvVar(EnvVars.IdpStudentUrl),
+            clientId: getEnvVar(EnvVars.IdpStudentClientId),
+            scope: SCOPE,
+            responseType: RESPONSE_TYPE,
+        },
+        teacher: {
+            authority: getEnvVar(EnvVars.IdpTeacherUrl),
+            clientId: getEnvVar(EnvVars.IdpTeacherClientId),
+            scope: SCOPE,
+            responseType: RESPONSE_TYPE,
+        },
+    };
+}

backend/src/exceptions.ts

@@ -0,0 +1,13 @@
+export class UnauthorizedException extends Error {
+    status = 401;
+    constructor(message: string = 'Unauthorized') {
+        super(message);
+    }
+}
+
+export class ForbiddenException extends Error {
+    status = 403;
+    constructor(message: string = 'Forbidden') {
+        super(message);
+    }
+}

backend/src/middleware/auth/auth.ts

@@ -0,0 +1,141 @@
+import { EnvVars, getEnvVar } from '../../util/envvars.js';
+import { expressjwt } from 'express-jwt';
+import { JwtPayload } from 'jsonwebtoken';
+import jwksClient from 'jwks-rsa';
+import * as express from 'express';
+import * as jwt from 'jsonwebtoken';
+import { AuthenticatedRequest } from './authenticated-request.js';
+import { AuthenticationInfo } from './authentication-info.js';
+import { ForbiddenException, UnauthorizedException } from '../../exceptions';
+
+const JWKS_CACHE = true;
+const JWKS_RATE_LIMIT = true;
+const REQUEST_PROPERTY_FOR_JWT_PAYLOAD = 'jwtPayload';
+const JWT_ALGORITHM = 'RS256'; // Not configurable via env vars since supporting other algorithms would
+// Require additional libraries to be added.
+
+const JWT_PROPERTY_NAMES = {
+    username: 'preferred_username',
+    firstName: 'given_name',
+    lastName: 'family_name',
+    name: 'name',
+    email: 'email',
+};
+
+function createJwksClient(uri: string): jwksClient.JwksClient {
+    return jwksClient({
+        cache: JWKS_CACHE,
+        rateLimit: JWKS_RATE_LIMIT,
+        jwksUri: uri,
+    });
+}
+
+const idpConfigs = {
+    student: {
+        issuer: getEnvVar(EnvVars.IdpStudentUrl),
+        jwksClient: createJwksClient(getEnvVar(EnvVars.IdpStudentJwksEndpoint)),
+    },
+    teacher: {
+        issuer: getEnvVar(EnvVars.IdpTeacherUrl),
+        jwksClient: createJwksClient(getEnvVar(EnvVars.IdpTeacherJwksEndpoint)),
+    },
+};
+
+/**
+ * Express middleware which verifies the JWT Bearer token if one is given in the request.
+ */
+const verifyJwtToken = expressjwt({
+    secret: async (_: express.Request, token: jwt.Jwt | undefined) => {
+        if (!token?.payload || !(token.payload as JwtPayload).iss) {
+            throw new Error('Invalid token');
+        }
+
+        const issuer = (token.payload as JwtPayload).iss;
+
+        const idpConfig = Object.values(idpConfigs).find((config) => config.issuer === issuer);
+        if (!idpConfig) {
+            throw new Error('Issuer not accepted.');
+        }
+
+        const signingKey = await idpConfig.jwksClient.getSigningKey(token.header.kid);
+        if (!signingKey) {
+            throw new Error('Signing key not found.');
+        }
+        return signingKey.getPublicKey();
+    },
+    audience: getEnvVar(EnvVars.IdpAudience),
+    algorithms: [JWT_ALGORITHM],
+    credentialsRequired: false,
+    requestProperty: REQUEST_PROPERTY_FOR_JWT_PAYLOAD,
+});
+
+/**
+ * Get an object with information about the authenticated user from a given authenticated request.
+ */
+function getAuthenticationInfo(req: AuthenticatedRequest): AuthenticationInfo | undefined {
+    if (!req.jwtPayload) {
+        return;
+    }
+    const issuer = req.jwtPayload.iss;
+    let accountType: 'student' | 'teacher';
+
+    if (issuer === idpConfigs.student.issuer) {
+        accountType = 'student';
+    } else if (issuer === idpConfigs.teacher.issuer) {
+        accountType = 'teacher';
+    } else {
+        return;
+    }
+    return {
+        accountType: accountType,
+        username: req.jwtPayload[JWT_PROPERTY_NAMES.username]!,
+        name: req.jwtPayload[JWT_PROPERTY_NAMES.name],
+        firstName: req.jwtPayload[JWT_PROPERTY_NAMES.firstName],
+        lastName: req.jwtPayload[JWT_PROPERTY_NAMES.lastName],
+        email: req.jwtPayload[JWT_PROPERTY_NAMES.email],
+    };
+}
+
+/**
+ * Add the AuthenticationInfo object with the information about the current authentication to the request in order
+ * to avoid that the routers have to deal with the JWT token.
+ */
+const addAuthenticationInfo = (req: AuthenticatedRequest, res: express.Response, next: express.NextFunction) => {
+    req.auth = getAuthenticationInfo(req);
+    next();
+};
+
+export const authenticateUser = [verifyJwtToken, addAuthenticationInfo];
+
+/**
+ * Middleware which rejects unauthenticated users (with HTTP 401) and authenticated users which do not fulfill
+ * the given access condition.
+ * @param accessCondition Predicate over the current AuthenticationInfo. Access is only granted when this evaluates
+ *                        to true.
+ */
+export const authorize =
+    (accessCondition: (auth: AuthenticationInfo) => boolean) =>
+    (req: AuthenticatedRequest, res: express.Response, next: express.NextFunction): void => {
+        if (!req.auth) {
+            throw new UnauthorizedException();
+        } else if (!accessCondition(req.auth)) {
+            throw new ForbiddenException();
+        } else {
+            next();
+        }
+    };
+
+/**
+ * Middleware which rejects all unauthenticated users, but accepts all authenticated users.
+ */
+export const authenticatedOnly = authorize((_) => true);
+
+/**
+ * Middleware which rejects requests from unauthenticated users or users that aren't students.
+ */
+export const studentsOnly = authorize((auth) => auth.accountType === 'student');
+
+/**
+ * Middleware which rejects requests from unauthenticated users or users that aren't teachers.
+ */
+export const teachersOnly = authorize((auth) => auth.accountType === 'teacher');

backend/src/middleware/auth/authenticated-request.d.ts

@@ -0,0 +1,9 @@
+import { Request } from 'express';
+import { JwtPayload } from 'jsonwebtoken';
+import { AuthenticationInfo } from './authentication-info.js';
+
+export interface AuthenticatedRequest extends Request {
+    // Properties are optional since the user is not necessarily authenticated.
+    jwtPayload?: JwtPayload;
+    auth?: AuthenticationInfo;
+}

backend/src/middleware/auth/authentication-info.d.ts

@@ -0,0 +1,11 @@
+/**
+ * Object with information about the user who is currently logged in.
+ */
+export type AuthenticationInfo = {
+    accountType: 'student' | 'teacher';
+    username: string;
+    name?: string;
+    firstName?: string;
+    lastName?: string;
+    email?: string;
+};

backend/src/middleware/cors.ts

@@ -0,0 +1,7 @@
+import cors from 'cors';
+import { EnvVars, getEnvVar } from '../util/envvars.js';
+
+export default cors({
+    origin: getEnvVar(EnvVars.CorsAllowedOrigins).split(','),
+    allowedHeaders: getEnvVar(EnvVars.CorsAllowedHeaders).split(','),
+});

backend/src/routes/auth.ts

@@ -0,0 +1,23 @@
+import express from 'express';
+import { getFrontendAuthConfig } from '../controllers/auth.js';
+import { authenticatedOnly, studentsOnly, teachersOnly } from '../middleware/auth/auth.js';
+const router = express.Router();
+
+// Returns auth configuration for frontend
+router.get('/config', (req, res) => {
+    res.json(getFrontendAuthConfig());
+});
+
+router.get('/testAuthenticatedOnly', authenticatedOnly, (req, res) => {
+    res.json({ message: 'If you see this, you should be authenticated!' });
+});
+
+router.get('/testStudentsOnly', studentsOnly, (req, res) => {
+    res.json({ message: 'If you see this, you should be a student!' });
+});
+
+router.get('/testTeachersOnly', teachersOnly, (req, res) => {
+    res.json({ message: 'If you see this, you should be a teacher!' });
+});
+
+export default router;

backend/src/routes/login.ts

@@ -1,14 +0,0 @@
-import express from 'express';
-const router = express.Router();
-
-// Returns login paths for IDP
-router.get('/', (req, res) => {
-    res.json({
-        // Dummy variables, needs to be changed
-        // With IDP endpoints
-        leerkracht: '/login-leerkracht',
-        leerling: '/login-leerling',
-    });
-});
-
-export default router;

backend/src/util/envvars.ts

@@ -1,5 +1,9 @@
 const PREFIX = 'DWENGO_';
 const DB_PREFIX = PREFIX + 'DB_';
+const IDP_PREFIX = PREFIX + 'AUTH_';
+const STUDENT_IDP_PREFIX = IDP_PREFIX + 'STUDENT_';
+const TEACHER_IDP_PREFIX = IDP_PREFIX + 'TEACHER_';
+const CORS_PREFIX = PREFIX + 'CORS_';
 
 type EnvVar = { key: string; required?: boolean; defaultValue?: any };
 
@@ -11,6 +15,15 @@ export const EnvVars: { [key: string]: EnvVar } = {
     DbUsername: { key: DB_PREFIX + 'USERNAME', required: true },
     DbPassword: { key: DB_PREFIX + 'PASSWORD', required: true },
     DbUpdate: { key: DB_PREFIX + 'UPDATE', defaultValue: false },
+    IdpStudentUrl: { key: STUDENT_IDP_PREFIX + 'URL', required: true },
+    IdpStudentClientId: { key: STUDENT_IDP_PREFIX + 'CLIENT_ID', required: true },
+    IdpStudentJwksEndpoint: { key: STUDENT_IDP_PREFIX + 'JWKS_ENDPOINT', required: true },
+    IdpTeacherUrl: { key: TEACHER_IDP_PREFIX + 'URL', required: true },
+    IdpTeacherClientId: { key: TEACHER_IDP_PREFIX + 'CLIENT_ID', required: true },
+    IdpTeacherJwksEndpoint: { key: TEACHER_IDP_PREFIX + 'JWKS_ENDPOINT', required: true },
+    IdpAudience: { key: IDP_PREFIX + 'AUDIENCE', defaultValue: 'account' },
+    CorsAllowedOrigins: { key: CORS_PREFIX + 'ALLOWED_ORIGINS', defaultValue: '' },
+    CorsAllowedHeaders: { key: CORS_PREFIX + 'ALLOWED_HEADERS', defaultValue: 'Authorization,Content-Type' },
 } as const;
 
 /**