2025SELab2-project-Dwengo/backend/src/middleware/auth/checks/auth-checks.ts
2025-05-15 19:01:10 +00:00

61 lines
2.6 KiB
TypeScript

import { AuthenticationInfo } from '../authentication-info.js';
import { AuthenticatedRequest } from '../authenticated-request.js';
import * as express from 'express';
import { RequestHandler } from 'express';
import { UnauthorizedException } from '../../../exceptions/unauthorized-exception.js';
import { ForbiddenException } from '../../../exceptions/forbidden-exception.js';
import { envVars, getEnvVar } from '../../../util/envVars.js';
import { AccountType } from '@dwengo-1/common/util/account-types';
/**
* 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 function authorize<P, ResBody, ReqBody, ReqQuery, Locals extends Record<string, unknown>>(
accessCondition: (auth: AuthenticationInfo, req: AuthenticatedRequest<P, ResBody, ReqBody, ReqQuery, Locals>) => boolean | Promise<boolean>
): RequestHandler<P, ResBody, ReqBody, ReqQuery, Locals> {
// Bypass authentication during testing
if (getEnvVar(envVars.RunMode) === 'test') {
return async (
_req: AuthenticatedRequest<P, ResBody, ReqBody, ReqQuery, Locals>,
_res: express.Response,
next: express.NextFunction
): Promise<void> => {
next();
};
}
return async (
req: AuthenticatedRequest<P, ResBody, ReqBody, ReqQuery, Locals>,
_res: express.Response,
next: express.NextFunction
): Promise<void> => {
if (!req.auth) {
throw new UnauthorizedException();
} else if (!(await accessCondition(req.auth, req))) {
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 === AccountType.Student);
/**
* Middleware which rejects requests from unauthenticated users or users that aren't teachers.
*/
export const teachersOnly = authorize((auth) => auth.accountType === AccountType.Teacher);
/**
* Middleware which is to be used on requests no normal user should be able to execute.
* Since there is no concept of administrator accounts yet, currently, those requests will always be blocked.
*/
export const adminOnly = authorize(() => false);